JPH11149269A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To see a display face of wider range from the direction of wider range by constituting a display device so that it is provided with a light conducting body of the outside being a convex cured face and transmitting light and a display body having the display face opposed to the outside, and the light conducting body adheres to the display face through no gas layer. SOLUTION: A light conducting body 11 and a display body 14 are fixed together with an adhesive of extremely high transparency, on the back side 11b opposed to the outside 11a and on the display face 14a formed with an image. The boundary between the adhesive and the back side 11b and the boundary between the adhesive and the display face 14a adhere closely to each other through no gas layers. A doughnut-like first light source 12 projects light from the vicinity of the lower part of the light conducting body 11 to the light conductive body 11. The display body 14 is formed with an image such as a letter or a figure, formed into a cylinder form of thin thickness, and translucent of white or milk-white, a second light source 13 projects light toward the back side of the display body 14, and hence the display face can be seen from the wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device such as a signboard, a guide plate, a display tower or the like which is placed indoors or outdoors, and more particularly to a display body for forming display information such as characters and figures as a display surface. The present invention relates to a display device related to a light-transmitting light guide for displaying.

[0002]

2. Description of the Related Art As a display device capable of observing a display surface from a wider azimuth range, a cylindrical display device having a cylindrical display surface is well known. The observable azimuth of this cylindrical display device is as wide as 360 degrees.

Further, as a method of illuminating the columnar display device, a back illumination type in which a light source is provided inside a cylindrical display body is well known. Further, as an example of a display device that directly illuminates the display surface from the front side, a display device having a structure in which a long arm is protruded from the upper or lower part of a display body and an illumination lamp is attached to the end thereof is well known. Japanese Patent Application Laid-Open No. 5-273926 discloses a technique for reducing the length of a normal arm, which needs to be approximately the same as the height of a display surface, to about 1/4 in order to make the brightness of the display surface somewhat uniform. Have been.

[0004] As another example of the back illumination type, a box type display device having a structure in which a light source such as a fluorescent lamp is placed in a box and the displayed content is recognized as transmitted light is well known. A display device using a light guide type surface light source as a light source for back lighting is disclosed in Japanese Unexamined Patent Publication No. Hei.
184079. Each of the light guide type surface light sources is used as a light source of a rear illumination display device.

FIG. 45 is a view for explaining the basic structure and operation principle of a conventional display device, and is a perspective view of a light guide plate type display device using a surface light source as a light source for back illumination. The plate-shaped light guide 311 is formed of an acrylic resin or the like. The light source 313 projects light to the side end surface of the light guide 311. The reflector 314 reflects a part of the light from the light source 313 and emits the light to the side end surface of the light guide 311. The light scattering plate 315 is placed on the front side of the light guide 311. The light scattering / reflecting surface 316 is formed directly on the back side of the light guide 311. The display 312 is placed outside the light guide 311 with the light scattering plate 315 interposed therebetween. Although the light scattering / reflecting surface 316 is a surface having no thickness, the light scattering / reflecting surface 316 is shown with a thickness for clarifying the position.

FIG. 46 is a sectional view taken along line AA of FIG. The light guide 311 has surfaces such as an outer surface 311a, a back surface 311b, and a side end surface 311c. The light scattering plate 315 is placed parallel to the outer surface 311a. Light emitted from the light source 313 disposed close to the side end face 311c enters the light guide 311 from the side end face 311c and travels while repeating reflection. That is, the light that reaches the back side surface 311b from the side end surface 311c is reflected by the light scattering reflection surface 316 formed there, and reaches the outer side surface 311a. In addition to this light, the light that reaches the outer surface 311a is
There is light directly from the side end face 311c. These outer surfaces 3
11a, the light whose incident angle is larger than the critical angle is totally reflected by the outer surface 311a and is again reflected on the back surface 311b.
To reach. On the other hand, light having an incident angle smaller than the critical angle transmits through the outer surface 311a, reaches the light scattering plate 315, and is diffused. Part of the diffused light is emitted light, and the display 312
Is a surface light source.

As described above, light is guided along the light guide by the reflection on the light scattering / reflecting surface 316, the total reflection on the front surface, or the diffusion on the light scattering plate 315, and a part of the light is guided. The light emitted from the light guide through the scattering plate 315 forms a surface light source. The surface light source illuminates the display 312 from behind.

A display device using a light guide type surface light source is:
This is a type in which display contents are transmitted to an observer by transmitted light. The light guide plate is not limited to a flat light guide plate having a constant thickness as described above, but may have a shape in which the center portion is thin and the end portions are thick. Further, as disclosed in Japanese Utility Model Laid-Open Publication No. 48-30983, a liquid is applied to the light guide. Various types, such as those using a light guide, are known, such as the shape and material of the light guide. Recently, many patent applications have been filed especially for backlights of liquid crystal display devices.

In the following description, unless otherwise specified, a display surface is a surface on which display information is formed on a display body, and an outer surface is a surface on a light guide or a display portion described later. The light reflected by the display surface is a surface from which light is emitted to the outside, and the back surface and the side end surface are surfaces of the light guide, respectively, the surface facing the outer surface, and the narrow side portion. It is the end face of.

[0010]

However, the conventional display device has the following problems. In a cylindrical display device, the range of the display surface that can be observed from a fixed position is limited to a range of up to 2π at the central angle of the cylindrical display surface even if it is the widest. In addition, as the column display surface moves away from the central portion looking toward the front and toward the edge, the display surface becomes obliquely opposed to the viewer, and the display content is more strongly compressed as approaching the outer edge portion. To be observed.

The back-illuminated cylindrical display device requires that the display body be translucent and have a relatively high transmittance. Also, in combination with the fact that the display content is more strongly compressed and observed as approaching the outer edge described above, many of them display extremely rough display figures like a barber shop display tower, It is difficult to use a high-quality printed matter by a highly developed printing technique as a display body.

The direct illumination type display device disclosed in Japanese Patent Application Laid-Open No. 5-273926 has a very large illumination space because the arm portion to which the illumination lamp is attached protrudes. In the box-type display device, the distance between the display surface and the light source needs to be correspondingly large in order to make the brightness of the display surface uniform, and the number of light sources is also required accordingly.

Further, in the case of the above-mentioned display devices using back lighting, such as the above-mentioned box-shaped display device and the display device using a light guide type light source, the display body is translucent and high as in the case of the columnar display device. There are restrictions on the display, such as the need for transmittance.

The present invention has been proposed to solve the above problems, and provides a display device capable of viewing a wider range of display surfaces from a wider range of azimuths. A display device having a narrow illumination space is provided.

A first object of the present invention is to provide an easy-to-read display device which has a wide range of azimuths in which the display surface can be observed, and in which the deformation of the display content at the outer edge portion is reduced. A second object of the present invention is to provide a display device capable of illuminating a display surface from a front side in a narrow illumination space.

A third object of the present invention is to provide a display device which can illuminate the display surface from the front side by illuminating the display surface only from the back side. A fourth object of the present invention is to provide a display device capable of illuminating a display surface from both a back side and a front side in a narrow illumination space.

A fifth object of the present invention is to return light that has been emitted in a direction not useful in the conventional display device to the display surface again,
It is an object of the present invention to provide an efficient display device that changes effective light to illuminate a display surface.

[0018]

The present invention employs the following means in order to solve the above-mentioned problems. The invention according to claim 1 is a display device comprising: a light-transmitting light guide whose outer surface is a convex curved surface; and a display having a display surface facing the outer surface. The incident light from any point on the outer surface is closer to the arbitrary point than the focal point of the incident light,
And at a position distant from the outer surface, intersect with the display surface of the display body, the light guide is in close contact with the display surface without a gas layer, a display device, is there.

According to a second aspect of the present invention, there is provided the display device according to the first aspect, wherein the first illuminating portion and / or the display surface of the display body project light toward a side end surface of the light guide. A lighting unit having a second lighting unit for projecting light toward the surface on the opposite side of the display device.

According to a third aspect of the present invention, in the display device according to the first or second aspect, the light guide is orthogonal to the plane through a conductor whose outer surface is a smooth curve on a plane. A column surface with a straight line as a generating line, or a conical surface with a straight line passing through a point outside the plane through the conducting wire as a generating line, the display body has a smooth curved surface on the plane. A display device characterized by being a columnar surface having a straight line passing through a conductor and orthogonal to the plane as a generating line, or a conical surface having a generating line as a straight line passing through the conductor and passing through a point outside the plane. It is.

According to a fourth aspect of the present invention, in the display device according to the first or second aspect, the light guide has a cylindrical shape, a hollow cylindrical shape, a centrally symmetric cone, and a centrally symmetric cone. A hollow conical body, a columnar body having a part of a conducting wire on a plane formed into an arc having a central angle smaller than 2π and having a straight line perpendicular to the plane passing through the conducting wire as a generatrix, and having an outwardly convex columnar surface; A hollow columnar body having the shape of the columnar surface, convex outwardly with a line passing through the conducting line at a point other than a point on the central axis perpendicular to the plane passing through the center of the arc and intersecting the plane; The display device may be any one of the above-mentioned group of shapes, a conical surface having a conical surface, a hollow conical surface having the shape of the conical surface.

According to a fifth aspect of the present invention, there is provided a cylindrical body having an outer surface having a cylindrical surface, a hollow cylindrical body having an outer surface having a cylindrical surface, and a conical body having an outer surface having a centrally symmetrical conical surface. Is a hollow conical shape having a central axis symmetrical conical surface, and a part of the conductor whose outer surface is on a plane is formed into an arc having a central angle smaller than 2π and larger than π / 20, and is orthogonal to the plane through the arc. A columnar surface that is a convex columnar surface with a straight line as the generating line, a hollow columnar shape that is the shape of the columnar surface, intersects the plane on the central axis perpendicular to the plane through the center of the arc Any one of the above group of shapes, such as a pyramidal shape that is an outwardly convex conical surface having a line other than a point and a straight line passing through the circular arc as a generating line, a hollow conical surface shape that is the shape of the conical surface, and A light guide having a central or axially symmetric single-layer or multilayer structure made of one or more materials, and a display surface Is a centrally symmetric rotating surface, or a part of the display surface is a central angle of the centrally symmetric rotating surface which is smaller than 2π and larger than π / 20, and the display surface is not interposed with a gas layer. Adhere to the light guide,
And a radius Rc of the outer surface of the light guide at an arbitrary cross section where a center axis of the outer surface coincides with a center axis of the display surface and is orthogonal to the center axis of the light guide, and A refractive index na of air in contact with the side surface, a radius R of the display surface,
The relationship between the refractive index nsi of the material in contact with the display surface, the radius Rs of the total reflection surface S0 most strongly regulated, and the refractive index ns of the material in contact with the outside of the total reflection surface S0 is different from the display surface. When the total reflection surface S0 that regulates the path of light reaching the side surface by total reflection exists inside the light guide having a multilayer structure, the following inequalities A and B are simultaneously satisfied, or C and E is established when the light guide is installed at a position satisfying the condition that D is satisfied at the same time, and the total reflection surface that regulates the light path from the display surface to the outer surface by total reflection does not exist inside the light guide. And a display body installed at a condition position. ns / na ≦ Rc / Rs ≦ 1.25 · ns / na (inequality A) Rs / R ≦ nsi / ns (inequality B) 0.5 · nsi / na ≦ Rc / R <nsi / na ... (inequality C) Rc / Rs <ns / na ... (inequality D) 0.5 nsi / na ≤ Rc / R ≤ 1.25 nsi / na ... (inequality E) The display device according to claim 5, wherein
The illumination device further includes a first illumination unit that emits light toward a side end surface of the light guide and / or a second illumination unit that emits light toward a back surface of the display body. It is a display device characterized by the following.

According to a seventh aspect of the present invention, there is provided a light guide having a single-layer or multi-layer structure having an outer surface which is at least a part of a spherical surface and symmetrical with respect to a center point made of a single material or a plurality of materials; A translucent or transparent display body that is a part of a spherical surface and closely adheres to the light guide without interposing the display surface with a gas layer, and an illuminating unit including a point-like or spherical illumination unit. A display device comprising:
The center of the outer surface and the center of the display surface coincide with each other, and the radius Rc of the outer surface of the light guide at an arbitrary cross section passing through the center of the light guide, and the refraction of air in contact with the outer surface. Rate na, the radius R of the display surface, the refractive index nsi of the material in contact with the display surface, the radius Rs of the total reflection surface S0 that most strongly regulates, and the refractive index ns of the material in contact with the outside of the total reflection surface S0. The total reflection surface S0 restricts the path of light from the display surface to the outer surface by total reflection.
Is a multilayer structure existing inside the light guide, the following inequalities A and B are simultaneously satisfied, or the inequality is set at a position where C and D are simultaneously satisfied. The display device is characterized in that when a total reflection surface for regulating a light path to a side surface by total reflection does not exist inside the light guide, the light guide is installed at a position where E is satisfied. ns / na ≦ Rc / Rs ≦ 1.25 · ns / na... Inequality A Rs / R ≦ nsi / ns... Inequality B 0.5.nsi / na ≦ Rc / R <nsi / na... Inequality C Rc / Rs <ns / na inequality D 0.5 · nsi / na ≦ Rc / R ≦ 1.25 · nsi / na inequality E In all of the inventions according to claims 1 to 7 configured as described above. The outer surface of the light guide has a smooth outwardly convex curved surface, and the display surface is in close contact with the light guide without a gas layer. That is, the light guide functions as a convex lens having a display surface inside the lens.

According to the first aspect of the present invention, the display surface is always located closer to the outer surface than the observer than the focal point of the lens, and the display surface is located farther from the outer surface. Therefore, the image of the display figure drawn on the display surface that can be seen from the outside is an erect image without inversion in the vertical and horizontal directions.
The image is enlarged to a finite size.

According to the second aspect of the present invention, the lighting means is added to the first aspect of the present invention. The positional relationship between the outer surface of the light guide and the display surface of the display is exactly the same, and the effect on the image of the display graphic is the same as in the first invention.

With respect to the illumination, when the first illuminating means for projecting light toward the side end surface of the light guide is used, light entering from the side end surface of the light guide and traveling toward the outer surface becomes the refractive index of air. The main part of the totally reflected light is displayed because the light is totally reflected on the outer surface of the light guide, which has a sufficiently large refractive index, and the display surface is in close contact with the light guide without passing through the gas layer. The light can reach the surface and illuminates the display surface from the front.

When the second illuminating unit for projecting light toward the back surface of the display body is used, light is transmitted through the display surface in the transparent or translucent body of the display surface. Of this light, light incident on the outer surface at an angle smaller than the critical angle becomes light that passes through the outer surface and is seen by an observer. Light incident at an angle larger than the critical angle is totally reflected on the outer surface,
The light returns to the display surface again and illuminates the display surface from the front. In this way, the display surface is illuminated from the front even though the display is illuminated from behind.

According to the third aspect of the present invention, the generatrix is a straight line, and the outer surface of the light guide is constituted by a set of the straight lines.
Therefore, there is no scaling of the image in the direction along the generatrix.
This means that if this bus is viewed diagonally, it will be viewed on a uniform scale everywhere. In a cross section parallel to the plane containing the conductor, the outer surface of the light guide is curved. Therefore, the image is enlarged according to the curvature of the outer surface. Moreover, if the conductor curve is freely changed, various deformed images can be produced on the plane parallel to the plane containing the conductor, but in the direction along the bus, there is no deformation of the image, or it is reduced to a constant scale wherever there is I can see

Further, in the case where the light guide is provided, since the outer surface of the light guide is a set of straight lines which are parallel or oblique to the light guiding direction, the incident angles of the outer surface with respect to the generatrix direction are equal. Light has the same reflection angle due to total reflection at any position on the outer surface.

According to the fourth aspect of the present invention, the outer surface of the light guide has a central axis symmetric cylindrical surface, a part of the central axis symmetric cylindrical surface, a central axis symmetric conical surface, or a center. It is part of an axisymmetric conical surface. Also, the conductor is a circle or a part of the conductor is an arc. The bus is a straight line,
With respect to the generatrix direction, the image is not seen in the direction along the generatrix, and is seen at a uniform scale everywhere when the generatrix is viewed obliquely. Also in the case where the illumination means is provided, the light having the same incident angle with respect to the generatrix direction of the outer surface has the same reflection angle by total reflection at any position on the outer surface.

In a cross section parallel to the plane including the conductor, the outer surface of the light guide is a circle or an arc. In this cross section, the curvature of the outer surface is uniform, the outer surface is symmetric about the central axis with respect to the direction of the observer, and when the outer surface is a cylinder, the outer surfaces in the cross section perpendicular to the generating line are all circles having the same radius. Or an arc. Therefore, even if the observer moves around the outer surface,
Since the outer surfaces have the same curvature, the displayed figure does not suddenly change due to the outer surface. Further, the appearance of the observer's image changes gently even if it changes. In particular, when the outer surface is a cylindrical surface, the curve created by the outer surface is the same regardless of the position of the generatrix, so if the position of the display surface with respect to the outer surface is the same, the position perpendicular to the generatrix at any position of the generatrix. The magnification of the image is the same.

According to the fifth aspect of the present invention, the shape of the outer surface and the display surface of the light guide is a cylindrical surface symmetrical with respect to the central axis, a conical surface symmetrical with the central axis, or the center of the cylindrical surface or the conical surface. Any part of the range of less than π / 2 and more than π / 20 at the central angle around the axis. In addition, the central axis of the outer surface and the central axis of the display surface coincide. Therefore, the relationship between the outer surface and the display surface in a cross section orthogonal to the central axis is a concentric circle or a partial arc of the concentric circle. For this reason, the appearance of the image on the display surface is exactly the same when viewed from a certain range of orientation. In particular, when the outer surface and the display surface are a cylindrical surface and a conical surface, the display contents can be viewed in the entire range of 360 degrees. I can do it.

When viewed in a cross section perpendicular to the central axis, the surface is a convex lens having a circular surface, and the display surface is located in this lens and is positioned at an equal distance from the surface of the lens.
With respect to the image of the display surface formed in this positional relationship, an image formed on the optical axis when the outer surface is viewed perpendicularly is emitted from a position in contact with the display surface, away from the optical axis position and closer to the peripheral portion of the outer surface. The image of the incoming light is formed at a position close to the outer surface, and the image of the light from the position closer to the periphery of the outer surface connects the outer surface from the observer tangentially beyond this outer surface. The image approaches the straight line, and finally comes into contact with this tangent line. When this final state is reached, the image on the display surface is seen to be maximized on the outer surface up to the tangential direction. The manner in which such an image is formed depends on the relationship between the radius of the outer surface and the radius of the display surface, and the display surface can be viewed in the maximum range, and the image in the maximum visible range can be viewed tangentially to the outer surface. There are optimal conditions that can be seen as images. If the radius of the outer surface becomes larger than the optimum condition, the image on the display surface becomes smaller, and an image can be formed only in a range smaller than the range in which the outer surface is viewed at the maximum. Conversely, when the radius of the outer surface is reduced, the image can be made full as in the case of the optimal condition, but the range of the display surface that can be viewed becomes smaller. The image formation becomes more complicated than the above description when the total reflection surface exists in the light guide, but the tendency is the same. Also, the visible range of the display surface is π / 6 or more at the emission angle, and the visual field range of the image viewed on the display surface is 80% or less of the maximum visual angle at which the outer surface is viewed in the tangential direction. It places restrictions on the radius of the side and the radius of the display surface. This restriction differs depending on whether or not there is a total reflection surface S0 inside the light guide, which regulates the path of light from the display surface to the outer surface by total reflection.

When the total reflection surface S0 exists, the condition that the radius Rc of the outer surface and the radius R of the display surface satisfy the expressions A and B at the same time or the expressions C and D are satisfied at the same time. It is determined from the relationship with the radius Rs of the total reflection surface S0 based on the conditions. This means that the light emitted from the display surface at an emission angle of π / 6 or more can be seen, and the outer surface can be seen as an image of 80% or more of the visual field range in which the outer surface is maximized. Further, the allowable range of the radius Rc of the outer surface and the radius R of the display surface is:
Rc / Rs = ns / n, which is the optimal condition for light tangentially exiting the display surface to exit the outer surface tangentially and reach the viewer.
a, and Rs / Rsi = nsi / ns.

When the total reflection surface S0 does not exist, the radius Rc of the outer surface and the radius R of the display surface are determined based on the condition that satisfies the expression (5). As described above, the light emitted from the display surface at an emission angle of π / 6 or more can be seen, and the outer surface can be seen as an image of 80% or more of the visual field range in which the maximum can be seen. Further, the allowable range of the radius Rc of the outer surface and the radius R of the display surface determined by the formula E is an optimal condition for light tangentially exiting the display surface to exit the outer surface tangentially and reach the observer. , Rc / R
= Nsi / na.

Further, the outer surface and the display surface of the light guide are both a circular or arc-shaped conductor, a central axis symmetrical conical surface or a cylindrical surface having a generatrix as a straight line, or a central angle around these central axes.
Any of the portions smaller than / 2 and larger than π / 20, and formation of an image in a plane orthogonal to the central axis is as described above. In the direction of the generatrix, there is no enlargement or reduction of the image.In the direction of the central axis seen by the observer, there is no enlargement or reduction of the image when the outer surface is cylindrical, and in the case of a conical surface, the generatrix is constant with respect to the central axis. The scale is reduced due to the angle, but the rate is constant.

According to a sixth aspect of the present invention, an illuminating means is added to the fifth aspect of the present invention, and the effect on the appearance of the image is as described above. The illumination uses the total reflection on the outer surface of the light guide, and has the same effect as the second aspect of the present invention. The difference from the invention according to claim 2 is that both the outer surface and the display surface of the light guide are a group of straight lines inclined parallel or oblique to the direction of guiding light, that is, the direction of the central axis of the light guide. is there.

Both the outer surface and the display surface of the light guide are formed as a circular or arc-shaped conductor and a central axis symmetrical conical surface with a generatrix as a straight line, a cylindrical surface, or π at a central angle around these central axes. /
Any part of the range smaller than 2 and larger than π / 20. Therefore, the light guide and the display surface form a group of straight lines that are parallel or oblique to the direction in which light is guided, that is, the center axis of the outer surface. Therefore, light having the same incident angle with respect to the generatrix direction of the outer surface has the same reflection angle due to total reflection at any position on the outer surface. Further, the generatrix of the display surface is also a straight line, and is a group of straight lines which are parallel to or obliquely inclined with respect to the generatrix of the outer surface, and can uniformly receive light reflected parallel to the outer surface.

According to the seventh aspect of the present invention, both the outer surface and the display surface are part of a spherical surface. Moreover, the center position is the same. Therefore, the relationship between the outer surface and the display surface in a cross section including the center is a concentric circle or a partial arc of the concentric circle. This is exactly the same as the fifth and sixth aspects of the present invention. The relationship between the display surface and its image on the cross section is as follows.
Same as claim 5. The difference from the invention of claim 5 is that the outer surface and the display surface are concentric in all directions including the center, that is, three-dimensionally.

Since the point-like or spherical light source is located at the center of the display surface, the display body is evenly illuminated from behind. The invention according to claim 8 is directed to a light guide having an outer surface having a flat shape or a smooth curved surface, a display having a display surface opposed to the outer surface, and a light guide which is directed toward a side end surface of the light guide. A lighting unit including a first illuminating unit that emits light and / or a second illuminating unit that emits light toward a back surface of the display body, wherein the display body includes the display surface. Is disposed at a predetermined distance from the outer surface and in close contact with the light guide without an intervening gas layer.

According to a ninth aspect of the present invention, there is provided a display having a translucent light diffusing sheet or a transparent sheet, and a first light guide which is in close contact with one surface of the display without interposing a gas layer. A second light guide that adheres to the other surface of the display body without a gas layer therebetween, and at least one side end surface of the first light guide or the second light guide. And a lighting means for projecting light toward one side.

According to a tenth aspect of the present invention, there is provided a first display having a translucent light diffusing sheet or a transparent sheet, a second display having a translucent light diffusing sheet or a transparent sheet, A first light guide that is sandwiched between one surface of the first display body and one surface of the second display body without interposing a gas layer therebetween; and the other of the first display body. A second light guide having an outer surface opposed to the other surface of the first display body, the second light guide body being in close contact with the surface without a gas layer interposed therebetween, and being provided on the other surface of the second display body. A third light guide that has an outer surface facing the other surface of the second display body and that is in close contact with the gas display without interposing a gas layer, and at least one side end surface of the first light guide; And a lighting unit for projecting light toward the display device.

According to the eighth aspect of the present invention, when the first illuminating unit that projects light toward the side end surface of the light guide is used, light enters from the side end surface of the light guide. Light directed to the outer surface is totally reflected by the outer surface of the light guide having a refractive index sufficiently higher than the refractive index of air. Moreover, since the display surface is in close contact with the light guide without passing through the gas layer, the main part of the totally reflected light can reach the display surface, and the light illuminates the display surface from the front. Further, the outer surface is limited to a flat surface or a curved surface having a relatively large radius of curvature, and is limited to a parallel or relatively gentle inclination with respect to the direction in which light is to be guided. Can be extremely focused,
There is no dispersion, and the reflection angle due to total reflection falls within a certain range at any position on the outer surface.

When the second illuminating unit for projecting light toward the back surface of the display body is used, light is transmitted through the display surface in the transparent or translucent body of the display surface. Of this light, light incident on the outer surface at an angle smaller than the critical angle is transmitted through the outer surface and becomes light to be viewed by an observer. Light incident at an angle larger than the critical angle is totally reflected on the outer surface,
The light returns to the display surface again and illuminates the display surface from the front. In this way, the display surface is illuminated from the front even though the display is illuminated from behind. In addition, since the outer surface is flat or a curved surface having a relatively large radius of curvature, light that is totally reflected by the outer surface and illuminates the display surface from the front is continuous without abrupt change due to the outer surface. It will change smoothly.

According to the ninth aspect of the present invention, the light guide is provided on the display surface side and the back side of the display body, and the second light guide is in close contact with the back side of the display body without interposing a gas layer. Light is projected toward at least one side end surface, and travels through the light guide to illuminate the display from behind. Since the display body is in the form of a translucent or transparent sheet, it transmits light illuminated from the back and enters the first light guide body which is in close contact with the display surface of the display body without passing through a gas layer. Light reaching the outer surface of the light guide and having an incident angle smaller than the critical angle passes through the outer surface and reaches the observer, and light having an incident angle larger than the critical angle is reflected. The reflected light reaches the display surface and illuminates the display surface because the first light guide and the display surface are in close contact with each other and there is no gas layer.

According to the tenth aspect, the first display body is sandwiched between the back surface of the first display body and the back surface of the second display body.
The light is projected toward at least one side end surface of the light guide, and propagates through the first light guide, and the first and second light guides are in close contact with the first light guide. The display body is illuminated from behind simultaneously. Since the first and second display bodies are translucent or transparent sheets, they transmit light illuminated from behind,
The light enters the second and third light guides that are in close contact with the display surfaces of the first and second display bodies, reaches the outer surfaces of the second and third light guides, respectively, and has an incident angle smaller than the critical angle. Is transmitted through the outer surface and reaches the observer, and light having an incident angle larger than the critical angle is reflected. The reflected light reaches the display surface and illuminates the display surface because the light guide and the display surface are in close contact with each other and there is no gas layer.

[0047] The invention of claim 11 is the display device according to any one of claims 5 to 10, wherein the display, the first display, or the second display is provided on a surface. A display device characterized by having a convex protrusion and / or a concave depression locally outside.

According to a twelfth aspect of the present invention, there is provided a light guide including an outer surface having a straight line group or a straight line group or a curve group having an inclination parallel to a light guiding direction, and a gas layer formed on the light guide. A display device having a display surface that is in close contact without interposition, and a lighting device that emits light to a side end surface of the light guide, wherein the degree of inclination of the display surface with respect to the outer surface is determined by the above-described method. The display device is characterized in that it is changed according to a distance from a side end surface of the light guide.

According to a thirteenth aspect of the present invention, there is provided a light guide having an outer surface having a flat or curved shape, a display having a display surface which is in close contact with the light guide without a gas layer therebetween, and A display device comprising: illuminating means for projecting light toward a side end face of a body; and partition means having a gas layer separated from both surfaces between the outer surface and the display surface. The means has a thickness smaller than one tenth of a distance between the outer surface and the display surface on the side end face and a thickness larger than 1 micrometer, and the partition means is fixed from the side end face side. A display device, wherein part of light directly projected on the display surface at a distance is blocked.

According to a fourteenth aspect of the present invention, there is provided the display device according to any one of the first to thirteenth aspects, wherein the light guide, the first light guide, the second light guide, or the light guide. The third light guide is a display device, which is a composite in which a transparent liquid is injected into a hollow transparent container.

The invention according to claim 15 is the display device according to claim 14, wherein the transparent liquid is distilled water or an aqueous solution containing a disinfectant or a coloring agent.

A sixteenth aspect of the present invention is the display device according to the fourteenth aspect, wherein the hollow transparent container is made of a flexible transparent resin. The invention according to claim 17 is the display device according to claim 14, wherein the display, the first display, or the second display is immersed in a transparent liquid. It is.

According to an eighteenth aspect of the present invention, in the display device according to the seventeenth aspect, the display, the first display, or the second display is formed of a transparent resin or a transparent plastic sheet. The display device is characterized in that the display device is tightly covered without a layer.

A nineteenth aspect of the present invention is the display device according to the seventeenth aspect, wherein the display, the first display, or the second display is the light guide or the first light guide. The display device moves relative to a light body, the second light guide, or the third light guide with time.

According to a twentieth aspect of the present invention, in the display device according to the eighteenth aspect, the display body, the first display body, or the second display body is a sheet, and the light guide is The display, the first display, or the second display.
A dedicated liquid reservoir for immersing the display body, wherein the display body or the first display body or the second display body is installed in the dedicated liquid reservoir. is there.

According to a twenty-first aspect of the present invention, a light-transmitting light guide,
A display body on which a display image is formed, a first reflection unit having a first reflection surface facing a side end surface of the light guide, and a second reflection surface having a second reflection surface facing one surface of the display body. 2 illuminating means comprising a light source located at a position facing both the first reflecting surface and the second reflecting surface;
A display device comprising:
The first reflection surface is arranged obliquely with respect to the side end surface of the light guide and the light source such that light emitted toward the reflection surface of the light guide is reflected toward the side end surface of the light guide. And the second light is emitted from the illumination means toward the second reflection surface so as to be reflected toward one surface of the display body.
Wherein the reflection surface is disposed obliquely with respect to one surface of the display body and the illumination means.

According to a twenty-second aspect of the present invention, a part of a conducting wire on a hollow cylindrical body, a hollow conical body, and a plane is formed into an arc having a central angle smaller than 2π and passing through the arc and orthogonal to the plane. A light guide which is a hollow columnar body having an outer convex columnar surface serving as a generatrix as an outer surface, or a light guide of any of the above-mentioned shape groups; a display means; and a fixing means for fixing the light guide. The display device according to claim 1, wherein the fixing unit is provided in a hollow portion of the light guide.

According to the eleventh aspect of the present invention, the newly added projections and depressions are such that the projections are closer to the outer surface than the other display surfaces, and the depressions are farther from the outer surface. For this reason, the projections or depressions become a three-dimensionally convex or concave surface, and the display surface can be seen as a convex or concave image.

According to the twelfth aspect of the present invention, when the degree of inclination of the display surface with respect to the outer surface is changed according to the distance from the side end surface of the light guide, the light totally reflected on the outer surface and the side end surface are obtained. The amount of light that directly reaches from the display unit per unit area of the display surface can be changed. When illuminating the display surface by entering light from the side end surface of the light guide, if the outer surface and the display surface are parallel, the display surface generally becomes darker as the distance from the side end surface increases. It is. this is,
It is difficult for the light entering from the side end face to be a perfect parallel ray, and there is a component of non-parallel light, and even with light of the same solid angle, the irradiation area increases as the distance from the side end face increases. This is because the farther the amount of light per unit area becomes, the smaller the amount of light becomes. By tilting the display surface with respect to the outer surface, the amount of light per unit area that is reflected on the outer surface and reaches the display surface can be adjusted, and the brightness of the display surface can be made uniform. In addition, naturally, the light that reaches the display surface directly from the side end face can be similarly adjusted. Further, it is possible to illuminate the display body from behind and adjust the light that exits the display surface and is reflected by the outer surface and returns.

According to the thirteenth aspect, a gas layer is inserted between the outer surface and the display surface, and total reflection occurs in the gas layer. Between the outer surface and this layer of gas, and if there is more than one layer of gas, between adjacent layers of gas,
While repeating total reflection, light is guided in a direction away from the light source, and when the gas layer is cut off, the light is released and becomes light illuminating the display surface.

According to the fourteenth aspect of the present invention, the light guide is a composite in which a transparent liquid is injected into a hollow transparent container, and the transparent liquid, together with the hollow container, has a strong effect on a light path and the like. Performs the optical function of the body. The hollow transparent container and the transparent liquid can be separated in each process such as production and transportation, and the liquid and the display body can easily adhere to each other without passing gas.

According to the fifteenth aspect, the transparent liquid is distilled water or an aqueous solution containing a bactericide and a coloring agent, and is easily available and inexpensive. The germicide can suppress the growth of aqueous plants such as micro-animals and algae, and can easily color the light guide with a coloring agent or the like. These fungicides,
If an appropriate coloring agent is selected, the occurrence of pollution and the like can be suppressed.

According to the sixteenth aspect of the present invention, the material of the hollow transparent container is a flexible transparent resin, and an inexpensive material such as flexible vinyl chloride can be used.
Production is easy. Further, it can be folded during the manufacturing process and transportation.

According to the seventeenth aspect of the present invention, the display body is immersed in the transparent liquid, so that the display body and the light guide can be easily brought into close contact with each other, and the display body can be brought into close contact with the light guide. Can be maintained and moved.

According to the eighteenth aspect of the present invention, the display body is closely covered with the transparent resin or the transparent plastic sheet without the gas layer therebetween. Thereby, the display body is protected from the transparent liquid of the light guide, and the display surface and the light guide can be in close contact with each other through the gas layer through the transparent resin or the transparent plastic sheet.

According to the nineteenth aspect of the invention, in order to temporally move the display surface of the display with respect to the outer surface of the light guide, the positional relationship between the display surface and the outer surface changes, and the image of the display figure is displayed. Changes over time.

According to the twentieth aspect of the present invention, a dedicated liquid reservoir for immersing the display body is provided along the back surface of the light guide having a shape conforming to the shape of the display body in the installed state. A sheet-shaped display is dipped and used. Therefore, the display is brought into a used state only by inserting the display into the dedicated liquid reservoir. Further, since the exclusive liquid reservoir contains liquid, the display surface can be brought into close contact with the light guide.

According to the twenty-first aspect, the first reflecting surface is located at a position facing the side end surface of the light guide, and the second reflecting surface is located at a position facing the back surface of the display. ing. A light source is placed at a position facing both the first reflecting surface and the second reflecting surface, and the light source generates a light beam traveling in at least the directions of both the first and second reflecting surfaces. The first reflecting surface adjusts the reflecting surface to reflect the light from the light source toward the side end surface of the light guide, and the second reflecting surface transfers the light from the light source to the back surface of the display. The reflective surface is adjusted so that it reflects toward the camera. Thus, the light emitted from a single light source can illuminate both the side end surface of the light guide and the back surface of the display.

According to the twenty-second aspect, each of the light guides has a hollow portion, and a fixing portion for supporting the display device is provided in the hollow portion. Therefore, the fixed portion is installed on the back side of the display. Thus, the fixing portion does not block the outer surface.

According to a twenty-third aspect of the present invention, there is provided a display device for making an object visible by transmitting the object, wherein the object has an object surface on which at least a part of the object is in close contact, and the object is opposed to the object with respect to the object. A display unit installed on the side and having an outer surface for displaying the object through the objective unit.

According to a twenty-fourth aspect of the present invention, there is provided the display device according to the twenty-third aspect, wherein the first illuminating unit for projecting light from one position with respect to the objective surface of the objective unit and / or the other with respect to the objective surface. And a lighting unit having a second lighting unit for projecting light from the position.

According to a twenty-fifth aspect of the present invention, there is provided the display device according to the twenty-third aspect, further comprising a display member for forming an image such as a character or a figure with an object that is in close contact with the objective surface. Device.

According to a twenty-sixth aspect of the present invention, in the display device according to the twenty-third aspect, the first illuminating section for projecting light to the objective section and / or the first illuminating section for the objective section A display device further comprising: an illuminating unit having a second illuminating unit for projecting light from the opposite side; and a display body for forming an image such as a character or a figure with an object that is in close contact with the objective unit. .

The invention according to claim 27 is the display device according to claim 26, wherein the light projected from the first lighting section and / or the light projected from the second lighting section and The light transmitted through the objective section is reflected by the outer surface and projected to the objective section.

According to the twenty-third aspect of the present invention, in the display device for displaying the object to be observed by the observer through the display device, the objective section makes the object adhere to the object surface,
The display unit displays the object on the display surface through the objective unit by being installed on the opposite side of the object unit with respect to the object.

According to the twenty-fourth aspect of the present invention, the first light source emits light from one position to the objective surface of the objective portion, thereby transmitting an object that is in close contact with the objective surface through the objective portion. Illuminate with light. The second light source emits light on the opposite side of the object plane emitted from the first light source,
Illuminate the object directly.

According to the twenty-fifth aspect, the display forms an image such as a character or a figure which can be observed by the observer. According to the twenty-sixth aspect, the display forms an image such as a character or a figure that can be observed by the observer. The first light source emits light from one position to the object plane of the object unit,
The display body that is in close contact with the object surface is illuminated with light transmitted through the object part. The second light source directly illuminates the display by projecting light on the opposite side of the object plane from which light is emitted from the first light source.

According to the twenty-seventh aspect, the first light source emits light from one position to the object plane of the object part, thereby directly moving the object in close contact with the object plane to the object part. Illuminate with transmitted light and light totally reflected by the display surface. The second light source illuminates the object with light transmitted through the objective surface and totally reflected by the display surface by projecting the light from the first light source onto the opposite side of the objective surface.

According to a twenty-eighth aspect of the present invention, in the display device according to any one of the twenty-third to the twenty-third aspect, the display section has a curvature circle at an arbitrary point on the outer surface which is the same as that of the outer surface. The display device is generated on the side.

A display device according to a twenty-ninth aspect of the present invention is the display device according to the twenty-eighth aspect, wherein the display portion has at least a part or all of a cylindrical surface or a conical surface. Device.

According to a thirtieth aspect of the present invention, there is provided the display device according to the twenty-eighth aspect, wherein the display portion has at least a part or all of a curved surface having a spherical surface or an oval shape. Is a display device.

According to a thirty-first aspect of the present invention, in the display device according to the twenty-eighth aspect, the display portion has a flat or smooth curved outer surface.

According to the twenty-eighth aspect of the present invention, the display section is configured such that a curvature circle at an arbitrary point on the display surface is generated on the same side of the display surface, so that the display portion is convex at any point on the display surface. It has a convex or concave curved surface and acts as a convex or concave lens.

According to the twenty-ninth aspect, the display portion functions as a smooth convex lens. Further, the display surface is linear with respect to the direction in which light is guided, and is parallel or at a fixed angle.

According to the thirtieth aspect, the display section functions as a smooth convex lens. According to the thirty-first aspect, the display unit is limited at any point on the outer surface without extremely converging or dispersing the luminous flux of the emitted light.

The invention of claim 32 is the display device according to any one of claims 23 to 31, wherein the objective section has an arbitrary shape. A thirty-third aspect of the present invention is the display device according to the thirty-second aspect, wherein the objective portion has at least a cylindrical surface or a conical surface or a part thereof. A display device.

According to a thirty-fourth aspect of the present invention, in the display device according to the thirty-second aspect, the objective portion is at least a part or all of a curved surface having a spherical surface or an oval shape. Is a display device.

The invention according to claim 35 is the display device according to claim 32, wherein the objective section has a flat or smooth curved display section.

According to the thirty-second aspect of the present invention, the shape of the objective portion is adjusted to the object that is in close contact. According to the thirty-third aspect of the present invention, at least a part of the objective surface is brought into close contact with a cylindrical or conical object, and functions as a smooth convex or concave lens in the horizontal direction.

According to the thirty-fourth aspect, at least a part of the object surface is brought into close contact with a spherical or oval object, and functions as a smooth convex or concave lens.
According to the thirty-fifth aspect of the present invention, the objective section makes an object having at least a part thereof a flat surface or a curved surface having a relatively large radius of curvature adhere to each other, and at any point on the objective surface, radiates the luminous fluxes of the incident light and the emitted light. Without converging or dispersing extremely,
Limited.

According to a thirty-sixth aspect, in the display device according to any one of the twenty-third to thirty-fifth aspects, incident light from an arbitrary point on the outer surface of the display portion is more than a focal point of the incident light. A display device, wherein the display device crosses the object plane of the object part at an arbitrary point.

[0092] The invention according to claim 37 is the display device according to any one of claims 23 to 36, further comprising a holding member that holds the objective unit by connecting to the display unit. The objective unit is a display device formed of a transparent liquid.

[0093] The invention according to claim 38 is the display device according to any one of claims 23 to 36, wherein a hollow portion surrounded by the objective section and the display section is formed. Display device.

The invention according to claim 39 is the display device according to claim 38, wherein the hollow portion contains a transparent substance. The invention according to claim 40 is the display device according to claim 39, wherein the hollow portion is filled with a transparent liquid.

According to the thirty-sixth aspect of the present invention, the image of the object observed by the observer is set as an erect image having no upside down, left and right. According to the thirty-seventh aspect of the present invention, the holding member is connected to the display unit to hold the objective portion, which is a transparent liquid, so as not to flow.

According to the thirty-eighth aspect of the present invention, by forming the hollow portion, the observer observes the object that is in close contact with the objective portion through the objective portion, the hollow portion, and the display portion.
According to the thirty-ninth aspect of the present invention, since the transparent material is contained in the hollow portion, the observer observes the object that is in close contact with the objective portion through the objective portion, the transparent material, and the display portion.

According to the forty-ninth aspect, since the transparent liquid is contained in the hollow portion, the observer observes the object that is in close contact with the objective portion through the objective portion, the transparent liquid, and the display portion. I do.

The invention of claim 41 is the invention of claim 24 or 2
41. The display device according to any one of 6 to 40, wherein the first lighting unit and the second lighting unit are the same.

The invention of claim 42 is the invention of claim 24 or 2
42. The display device according to any one of items 6 to 41, further comprising a reflection unit configured to reflect light emitted from the first illumination unit and / or the second illumination unit. A display device.

[0100] The invention according to claim 43 is the display device according to claim 42, further comprising a light scattering sheet for covering the first lighting section and / or the second lighting section. A display device.

According to the forty-first aspect, a part of the light emitted from the same light source is projected on the objective surface of the objective part, so that the object which is in close contact with the objective surface can be removed. The object is illuminated with the transmitted light. Another part illuminates the object directly by projecting light on the opposite side of the object plane.

According to the invention of claim 42, the reflecting member is
By reflecting the light emitted from the first light source and projecting the light onto the objective surface of the objective unit, the object that is in close contact with the objective surface is illuminated with the light transmitted through the objective unit. Further, the object is directly illuminated by reflecting light emitted from the second light source and projecting the light on the opposite side of the object plane.

According to the invention of claim 43, the light scattering sheet scatters light projected from the light source. The invention according to claim 44 is the display device according to any one of claims 25 to 43, wherein the display is a display device such as a CRT display device, a liquid crystal display device, or a plasma display device. It is a display device characterized by the following.

[0104] The invention according to claim 45 is the display device according to any one of claims 25 to 43, wherein the display body comprises:
A display device having a sheet shape. The invention according to claim 46 is the display device according to claim 45, wherein the display body is plural.

The invention of claim 47 is the invention of claim 45 or claim 4.
7. The display device according to 6, wherein the display body is movable. The invention of claim 48 is the display device according to any one of claims 45 to 47, wherein the display is a screen.

(49) The display device according to any one of (45) to (47), wherein the display is
A display device characterized in that characters, figures, and the like are formed by gaps, depressions, protrusions, and the like.

[0107] The invention according to claim 50 is the display device according to any one of claims 45, 48 and 49, characterized in that the display body is drawn with characters, figures and the like. A display device.

[0108] The invention according to claim 51 is the display device according to any one of claims 44 to 50, wherein the display body comprises:
A display device characterized in that at least a part thereof is transparent or translucent.

The invention according to claim 52 is the display device according to any one of claims 23 to 51, further comprising a dedicated liquid reservoir for installing a display member for forming an image such as a character or a figure. And a display device characterized by the following.

According to the forty-fourth aspect, the display image on the display device is made visible to the observer through the objective part and the display part. According to the forty-fifth aspect, the display image formed by the observer is made visible through the objective part and the display part.

[0111] According to the forty-sixth aspect, each display image is made visible to the observer through the objective section and the display section. According to the forty-seventh aspect, the change of each display image is made visible to the observer through the objective part and the display part.

According to the forty-eighth aspect, the display image projected to the observer is made visible through the objective part and the display part. According to the forty-ninth aspect, a display image formed by a gap, a dent, a projection, or the like is made visible to an observer through the objective unit and the display unit.

According to the fiftyth aspect of the present invention, the display image drawn by the observer is made visible through the objective part and the display part. According to the invention of claim 51, the light projected from the second light source is transmitted to the objective section.

According to the fifty-second aspect of the present invention, the display body is brought into a use state only by inserting the display body into the exclusive liquid reservoir.
Further, since the exclusive liquid reservoir contains liquid, the display surface can be brought into close contact with the objective portion.

[0115] The invention according to claim 53 is a display device, wherein at least a part of the display unit is transparent, and a holding member for closing an end of the display unit so that liquid can be stored inside the display unit.
And a support unit for supporting a display body to be displayed on the display unit inside the display unit.

The invention of claim 54 is the display device according to claim 53, wherein at least a part of the outer periphery of the horizontal section is circular or elliptical, and the thickness of the display section is Is extremely small compared to the radius of the outer periphery, and the support portion can be immersed in the water stored inside the display portion by forming the display body on which the flat image is formed in a flat shape or in a tubular shape. So that the ratio of the radius of the outer periphery to a value obtained by subtracting the distance between the outer periphery of the display unit and the display body from the radius of the outer periphery is equal to or less than the refractive index of the stored liquid. A display device.

The invention according to claim 55 is the display device according to claim 53, wherein at least a part of the outer periphery of the horizontal section is circular or elliptical, and the thickness of the display unit is Is extremely small compared to the radius of the outer periphery, and the support portion can be immersed in the water stored inside the display portion by forming the display body on which the flat image is formed in a flat shape or in a tubular shape. So that the ratio of the radius of the outer periphery to a value obtained by subtracting the distance between the outer periphery of the display unit and the display body from the radius of the outer periphery is equal to or more than the refractive index of the stored liquid. A display device.

The invention according to claim 56 is the display device according to claims 53 to 55, wherein the first illuminating means for projecting light inward from an end face of the display unit and / or the support unit. Second illumination means provided on the opposite side to the display unit with the display body interposed therebetween so as to project light on the display body;
Is a display device further comprising:

The invention according to claim 57 is the display device according to any one of claims 23 to 56, further comprising fixing means for fixing the display section, wherein the fixing means is The display device is provided at a position sandwiching the display body with respect to the display unit and the objective unit.

According to the invention of claim 53, the display portion functions as a smooth convex lens in one direction. The holding member prevents the liquid acting as a convex lens integrated with the display unit from flowing out. The support unit supports the display body observed by the observer.

According to the fifty-fourth aspect, the display portion is formed in a thin cylindrical shape so that the liquid acting as a convex lens integrally plays a role of the convex lens. The supporter supports the display in the liquid. The supporting position is
This is the position where the observer can observe the image of the display body as an erect image.

According to the fifty-fifth aspect of the present invention, the display portion is formed in a thin cylindrical shape so that the liquid acting as a convex lens integrally plays a role of the convex lens. The supporter supports the display in the liquid. The supporting position is
This is a position where the viewer can observe up to a partial area on the back side of the display, which can only be seen by moving around.

According to the fifty-sixth aspect, the first illuminating means emits light from the end face of the tubular display section to directly and directly contact the display body supported by the support section with the surface of the display section. Illuminate with light that is totally reflected. Further, the second illumination means emits light from the opposite side to the optical path emitted from the first illumination means, so that the display body supported by the support part is projected from the back side and on the surface of the display part. Illuminate with totally reflected light.

According to the fifty-seventh aspect, the fixing means includes:
The entire display device is fixed so as not to move or fall. Further, the fixing means is located at a position invisible to an observer.

[0125]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a columnar display device according to the first embodiment of the present invention. When the inner diameter is R, the outer diameter of the light guide 11 is m × R.
(A coefficient satisfying m> 1) and is formed of a material such as acrylic resin or glass. The refractive index of the light guide 11 is sufficiently larger than that of air, and light is transmitted. The donut-shaped first light source 12 emits light to the light guide 11 from near the lower portion of the light guide 11. Rod-shaped second light source 13
Is near the central axis of the light guide 11. The display 14 has an image such as a character or a figure formed thereon, has a very thin cylindrical shape, and is translucent white or milky white. The second light source 13 emits light toward the back surface of the display body 14.

FIG. 2 is a sectional view taken along the line BB passing through the central axis of the cylindrical display device of FIG. The light guide 11 has a radius of mx
An outer side surface 11a which is a cylindrical surface of R, a back side surface 11b which is a cylindrical surface of radius R, and a side end surface 1 closer to the first light source 12
1c and a far side end surface 11d. The reflector 15 reflects a part of the light from the first light source 12 by covering the first light source, and emits the light to the side end surface 11c. In FIG. 1, the reflector 15 is not shown in order to clearly show the first light source 12. The light guide 11 and the display 14 have a rear side surface 11b facing the outer side surface 11a.
And the display surface 14a on which an image is formed are fixed with an adhesive having extremely high transparency. The boundary between the adhesive and the back surface 11b and the boundary between the adhesive and the display surface 14a are in close contact with each other without a gas layer.
Further, the thickness of the adhesive layer is assumed to be sufficiently small and the refractive index is also equal to that of the light guide 11, and the description will be continued hereinafter by regarding the adhesive layer as a part of the light guide 11.

The close contact between the back side surface 11b of the light guide 11 and the display surface 14a of the display 14 is important in the present invention and will be described later in detail. FIG. 3 is a cross-sectional view of the columnar display device of FIG. 1 and 2 indicate the central axis of the light guide 11. This central axis is the z-axis. The plane orthogonal to the z-axis is represented by orthogonal coordinates of the x-axis and the y-axis orthogonal to each other, or polar coordinates using a radius and an angle. The BB section shown in FIG. 1 is a section passing through the z-axis. 2 is a cross section orthogonal to the z-axis.

Hereinafter, various embodiments using a cylindrical surface or a conical surface as the outer surface or the display surface will be described. In the description, the central axis of the light guide may be referred to as the z-axis, and a plane orthogonal to the z-axis may be referred to as an xy plane. In addition, when it is not necessary to particularly describe the position of the cross section and the direction in which the cross section is viewed, a cut plane passing through the z-axis which is the central axis is abbreviated as a BB cross section, and a cut plane orthogonal to the central axis is denoted by C-B.
Abbreviated as C section.

Next, the first light source 12 and the second light source 1
The path and function of light emitted from No. 3 will be described. The light from the first light source 12 is guided exclusively in the z-axis direction by the light guide 11, and becomes light for illuminating the display surface 14a from the front side. On the other hand, the light from the second light source 13 is light for illuminating the display 14 from behind. The different types of illumination light will be described individually.

First, the first light source 12 generates the side end surface 11.
The light which is projected on the light guide c and guided in the z-axis direction through the light guide 11 will be described. In this case, the outer surface 11a plays an important role.

FIG. 4 shows the first embodiment.
FIG. 3 is a diagram conceptually showing a path in the z-axis direction of light projected from a light source 12 of FIG. Light emitted from one point Q of the first light source 12 passes through the light guide 11 through three types of paths i, j, and k,
The point P on the display surface 14a is reached. The path h is a path that is emitted to the outside from the side end face 11d without reaching the display surface 14a. In addition, as is clear from FIG. 2, the light guide 11 is symmetric with respect to the central axis. Therefore, in describing the light guided in the z-axis direction, it is sufficient to describe only one side of the central axis. FIG. 4 also shows only one side. Strictly speaking, light emitted from the first light source 12 is refracted on the side end surface 11c and the side end surface 1d. However, since these refractions are irrelevant in describing the path of light, FIG.
In the illustration, this is ignored.

The path i is also provided on the outer surface 11a on the display surface 14a.
Is the path of the light that arrives at the point P without ever hitting it. The path j is a path that reaches the point P by being reflected only once on the outer surface 11a. The path k is a path that reaches the point P after being reflected at the point R on the display surface 14a before hitting the outer side surface 11a. Exiting the first light source 12, these paths i,
Light arriving at j and k is effective light for illuminating the display surface 14a. That is, the light is reflected by the display surface 14a and transmitted through the outer surface 11a to allow the observer to visually recognize the display figure. If the light guide 11 does not exist, all the light once reflected on the display surface 14a is radiated to the space on the observer side as it is.
However, in the case of the present invention in which the light guide 11 exists, a part of the light guide 11 is reflected by the outer side surface 11a to illuminate the display surface 14a again. Then, the remaining part transmits through the light guide 11 and becomes light for the observer to visually recognize the display surface 14a.

FIG. 5 shows that the light reflected on the display surface 14a is
A state where the light is split into reflected light and transmitted light on the outer side surface 11a is shown. The light that reaches the point P on the display surface 14a that is in close contact with the back surface 11b is reflected by the display surface 14a. In the figure,
The display surface 14a is regarded as the same as the back surface 11b. The display surface 14a is a scattering surface that can be observed from all directions, and the reflected light here has components in all directions as indicated by a plurality of arrows. These reflected lights reach the outer surface 11a. The component whose incident angle γ is larger than the critical angle θ is totally reflected and returns to the display surface 14a again. On the other hand, light whose incident angle γ is smaller than the critical angle θ is transmitted light according to the well-known law of refraction and emitted from the outer surface 11a to the outside of the display device. In this case, the outer surface 11a
In, reflection and transmission occur simultaneously. However, since the reflected light is smaller than the transmitted light, the incident angle γ smaller than the critical angle θ
Will be described assuming only transmitted light.

The point R and the point S on the outer surface 11a are
The point at which the incident angle γ and the critical angle θ when the light reflected at the point P on 4a reaches the outer side surface 11a becomes equal.
The light arriving between the point R and the point S has an incident angle γ and an outgoing angle δ.
The light is emitted out of the light guide 11 as shown by the arrow line. Since the light travels from a light guide having a large refractive index to a small air, the exit angle δ becomes larger than the incident angle γ and spreads over a wider range. The closer the incident angle is to the critical angle θ, the more the direction advances toward the outer surface 11a, and ultimately, the direction along the outer surface 11a. That is, even if the light guide 11 is present, the observable range is sufficiently wide as in the case where the light guide 11 is not present.

On the other hand, light having an incident angle γ larger than the critical angle θ and reaching outside the points R and S is totally reflected and becomes light for illuminating the display surface 14a again. As is clear from the above description, the presence of the light guide causes the light to jump out of the angle direction larger than the critical angle θ, and the display surface 14
The light which has hardly helped to observe a becomes the light for illuminating the display surface 14a again. The closest position that returns again is Dtan, where D is the distance between the display surface 14a and the outer surface 11a and θ is the critical angle of the outer surface 11a.
θ.

With the above configuration, the illumination efficiency when illuminating the display surface 14a is improved as follows. For example, as shown by a path j in FIG. 4, if the light guide 11 does not exist, the light radiated to the space irrelevant to the display device is directly reflected by the outer surface 11a for display. It is effectively used as light for illuminating the surface 14a. Two, as shown by a path k in FIG. 4, only light having an incident angle smaller than the critical angle θ out of the light reflected from the display surface 14a goes out of the outer surface 11a, and the critical angle θ Light having a larger incident angle becomes light for illuminating the display surface 14a again by total reflection. Three are irregular reflection on the display surface 14a and the outer surface 11a.
The light can be efficiently guided to the display surface located at a position distant from the light source by repeating the total reflection in the light source. further,
A relatively thin light guide, that is, light can be efficiently guided to a place away from the light source in a narrow illumination space, and the display surface can be illuminated from the front.

In the above description, the light guided in the z direction has been described, but light traveling in the circumferential direction perpendicular to the z direction will be briefly described. As is apparent from the cross-sectional view taken along the line CC in FIG. 3, the next arrival point of the light that is totally reflected on the outer surface 11a and transmitted in the circumferential direction is either the display surface 14a or the outer surface 11a again. Is. Which one is determined by two factors: the initial angle of incidence on the outer surface 11a and the ratio of the radii of the outer surface 11a and the display surface 14a. When the next arrival point is the display surface 14a, the light becomes effective light for illuminating the display surface 14a. However, the next point is the outer surface 11
In the case of a, since the incident angle becomes the same as the incident angle at the time of the previous total reflection, the light is totally reflected again. And the outer surface 11a
From the display surface 14a to the outer surface 11a.
It becomes invalid light that does not illuminate.

The manner in which light is guided in the light guide 11 has been described in the z-axis direction and the circumferential direction, focusing on the illumination light. Originally, it is necessary to discuss the total reflection and the like with the angle formed by the direction of the light as one vector and the normal to the surface on which the light shines. However, the direction in which light is desired to be guided from the light source is the z direction, and the light intensity in the circumferential direction is generally made as uniform as possible. If this condition is satisfied, the circumferential direction may be ignored as a secondary component, and only the way in which light is guided in the z-axis direction may be considered. In the present embodiment, the first light source 12 has a donut shape, but point light sources or spherical light sources may be arranged in a circle. An appropriate light source is selected according to the shape of the side end face 11c and the like, and a single light source or a plurality of light sources may be used.

Next, light emitted from the second light source 13 and illuminating the display 14 from behind will be described. The display 14 is a white or milky translucent body, and the ink drawn on the display surface 14a is sufficiently thin and has transparency. A representative example of such a display 14 is a printed matter printed on paper such as a calendar. Light emitted from the back of the display 14 passes through the display surface 14a and becomes scattered light having all directions. Therefore, the transmitted scattered light that passes through the display 14 and exits the display surface 14a exhibits the same behavior as the scattered light reflected on the display surface 14a described with reference to FIG. That is, in the transmitted scattered light emitted from each point on the display surface 14a,
Light whose incident angle on the outer side surface 11a is smaller than the critical angle θ passes through the outer side surface 11a, and becomes light for the observer to visually recognize the display surface 14a. Light having an incident angle larger than the critical angle θ is reflected by the outer surface 11a and becomes illumination light for illuminating other parts of the display surface 14a.

As described above, the observer can observe and recognize the display 14 with only two kinds of light, the transmitted light and the reflected light, by merely illuminating the translucent display 14 from behind. This is different from the case where the individual illuminations are performed independently, and a sharper feeling is felt, and an excellent unique illumination effect is obtained.

In the first embodiment, in order to illuminate the display 14 from behind, the entire display 14 is made of a white or milky translucent body. However, only a part of the material may be translucent and the other part may be opaque. The color is not limited to white or milky white. Also,
A transparent body may be used instead of a translucent body. However, in the case of a transparent body, it is effective to provide a translucent light diffusion sheet between the light source and the display body if it is necessary to prevent the back of the display body from being seen through. Naturally, when the display is not illuminated from behind, such a restriction on the display is unnecessary.

The lighting has been described above. Next, how the display screen looks will be described. Since the outer surface 11a of the light guide 11 is a cylindrical surface, the light guide 11 may be considered as a kind of lens. Then, the display surface 14a of the display body 14 as an object to be placed is located between the outer surface of the light guide 11 as a lens and the focal point, and the observer sees the virtual image. Since the outer side surface is a cylindrical surface, the center axis and the outer side surface are parallel to each other, and there is no enlargement or reduction of the image in the center axis direction (z-axis direction). Therefore, the deformation of the image on the plane perpendicular to the central axis may be considered.

FIG. 6 is a diagram for explaining how the image of the display figure is viewed, and is a cross-sectional view taken along a plane perpendicular to the central axis of the light guide 11. One component of the light that has exited the point Px on the display surface 14a reaches the outer surface 11a at a point Tx at an incident angle α, exits the light guide 11 at an emission angle η, and follows a path of a straight line jx. To reach the observer. The image of the point Px is given by an intersection Px ′ between a straight line ix connecting the point Px and the center point O and a straight line jx. It should be noted that the observer is sufficiently far from the outer surface 11a, and all the light reaching the observer through the outer surface 11a has a sufficiently small angle with the optical axis and is approximately parallel to the optical axis e. And is omitted from the figure.

FIG. 6 also shows a point Pm on the display surface where the displayed figure can be viewed as the largest image, and a point Pm ′ that becomes the image. The displayed figure can be viewed as the largest image when the light emitted from the display surface 14a exits the outer surface 11a in a tangential direction and reaches the observer. The range in which the display surface 14a can be seen to the maximum depends on the mutual relationship between the display surface 14a and a straight line im that is a path in the light guide 11 for light that exits the outer surface 11a in a tangential direction. When the radius of the display surface 14a is so small that it does not intersect the straight line im, the light that has exited the display surface 14a cannot exit the outer surface 11a in the tangential direction, and the display surface 11a can be viewed as an image having the maximum visual field. become unable.

The above description of the image forming method is based on well-known geometrical optics, and is easy to understand. The image of the range of the display surface from the point Q intersecting the optical axis f of the display surface 14a to the point Px through the point Px is G indicated by a thick line from the point Q to the point Px 'to the point Pm'. . The image G of the display surface
Shows only one side of the optical axis. Although it can be formed on the opposite side, it is omitted because it is complicated. Note that, in this specification, only one side of the optical axis is basically shown.

FIG. 6 shows the case where the observer is sufficiently far away, but the relationship with the case where the observer is close here will be described. If the observer is near the outer surface 11a, the angle between the line of sight looking at the outer surface 11a and the optical axis becomes a significant angle γ and cannot be ignored. When this angle is taken into consideration, the result obtained under a simplified and negligible condition, that is, under the condition that the observer is far enough, can be applied as it is or can be changed by a simple method. That is, as shown in the figure, the optical axis rotates around the central axis by an angle γ and f
It can be regarded as having changed from e to e. It is sufficient if the observer is sufficiently far away and the object H and the image H ′ having dropped their feet on the optical axis f have changed to I and I ′ perpendicular to the new optical axis e.
Even if the optical axis is changed from e to f, the positional relationship between Pm and Pm ', which are the vertices of the object and the image, does not change at all. However, both the object and the image change in height from the optical axis. Here, the Pm point is taken as an example, but this relationship holds at every point on the display surface.

The rate of change is the same for the object and the image. When the foot on the optical axis of the object and the image is closer to the center O as viewed from the observer, the rate of change w1 is greater than 1. The rate of change w2 when the distance is smaller and located farther from the center O
Is greater than one. The rate of change of one point on the display surface at the center angle 中心 with respect to the optical axis f can be easily derived from the figure as follows. w1 = Sin (χ−γ) / Sin (χ) (Equation 1) w2 = Sin (χ + γ) / Sin (χ) (Equation 2) Even if the optical axis changes, the object and the image Since the rate of each change is equal, the magnification of the image to the object is
It does not change even if the optical axis changes. However, if χ = 0,
Both the height of the object and the image with respect to the optical axis f become zero, and are excluded from the above definition of the rate of change, and the magnification is set to zero. χ = γ
In the case of, both the height of the object and the image with respect to the optical axis e become zero. Also in this case, it is excluded from the definition of the rate of change, and the amplification rate is set to zero.

As described above, it is easy to change from a case where the observer is far enough to a case where the observer is close.
In addition, since the result obtained assuming that the observer is far away can be applied to the case where the observer is close, in this specification, in order to make the explanation easy to understand, it is assumed that the observer is far enough. I will explain everything.

The characteristics of the image G on the display surface shown in FIG. 6 are extremely useful for the present invention and are as follows. The image can be formed outside the display surface 14a. As the display surface 14a is closer to the optical axis, an image is formed at a position closer to the display surface 14a,
The point Q on the display surface 14a crossing the optical axis is the same as the image Q
Can be. As the distance from the point Q intersecting the optical axis increases,
The image can be formed at a position distant from the display surface 14a, and even at the farthest position, the image cannot be formed outside a tangent connecting the observer and the outer surface 11a in a tangential direction. As a result, the display surface 14 shown in FIG.
As is clear from the image G of FIG.
In addition, a becomes a curved surface having a larger radius of curvature than the outer surface 11a, and is observed as an image closer to a flat surface, so that the display contents can be easily recognized. (2) The amplification factor increases as the image is located farther from the intersection Q with the optical axis. As a result, as the display surface 14a is viewed more obliquely as the distance from the intersection point Q with the optical axis increases, what is seen as being reduced in scale can be corrected and the degree of reduction can be reduced, and the image can be observed as a more easily viewable image. (3) π on one side at a central angle from the intersection Q with the optical axis
/ 2, it is possible to observe up to a partial area on the back side of the display body 11, and by aligning both sides of the optical axis, the range of the display surface 14a exceeding π at the central angle can be captured in the field of view. They are,
Each of them is a great feature that has never been seen as a display device.

Here, π is a circle ratio. In this specification, all units of angle are in radian unless otherwise indicated with "degree". Next, a description will be given of the optimum conditions for viewing the display surface in the maximum range and the maximum range as the maximum image.

It is optimal that the light tangentially exiting the display surface 14a is refracted tangentially on the outer surface 11a and reaches the observer. In FIG. 6, the case where the straight line im which is the path of the light emitted from the point Pm on the display surface 14a is in contact with the display surface 14a is a condition under which the display surface can be viewed in the maximum range. Then, the case where light emitted in the tangential direction from the display surface exits tangentially to the outside on the outer surface and reaches the observer is a condition that can be regarded as an image of the largest size. Light guide 1
1 is made of a single material, this condition can be easily derived, and the radius ratio m of the radius Rc of the outer surface 11a to the radius R of the display surface 14a is made equal to the refractive index n of the light guide. Rc / R = m = n (Equation 3) Optimum when the following holds. If the radius ratio m deviates from the optimum condition, the appearance of the image changes in a complicated manner. The appearance of the image when the radius ratio deviates from the optimum condition and the derivation of (Equation 3) will be described later in detail with a multilayer light guide.

The first embodiment in which both the outer surface and the display surface are cylindrical surfaces has been described in detail above. Next, an example of a plane corresponding to a special case where the radius of the cylindrical surface is infinitely large will be described. This will be described as a second embodiment.

FIG. 7 is a perspective view of a display device showing a second embodiment in which the outer side surface is a plane. Flat light guide 5
1. Linear light source 52 such as a fluorescent lamp, reflector 53, display 5
4 is provided.

FIG. 8 is a sectional view taken along the line AA shown in FIG.
Note that the AA cross section is a surface orthogonal to the outer surface and orthogonal to the length direction of the linear light source. Hereinafter, embodiments of various outer surfaces guided on the basis of a plane will be described. In the description, if the position of the cross section and the viewing direction can be read without particular explanation, a cross-sectional view taken along a plane perpendicular to the length direction of the linear light source placed along the side end face is taken along A-. A description will be made by abbreviated as an A sectional view. Also, this A-
The direction of a line formed by the intersection of the A section and the outer surface is defined as the z-axis direction, and a plane orthogonal to this direction is referred to as an xy plane. In addition,
The direction of the z-axis corresponds to the direction in which light introduced from the side end surface of the light guide in the light guide is guided.

The light guide 51 has an outer surface 51a and a back surface 5a.
1b, there are side end surfaces 51c and 51d. The outer side surface 51a and the back side surface 51b are planes parallel to each other. The reflector 53 has a first reflection surface 53a and a second reflection surface 53b.

The light guide 51 is made of a transparent material such as acrylic resin or glass as in the first embodiment, and the display 54 is fixed to the back side surface 51b with a transparent adhesive. The display body 54 has a display figure drawn on the surface of a white or milky translucent body, and has the display surface 54a facing the back surface 51b of the light guide. In the case of the second embodiment, as in the case of the first embodiment, the adhesion by the adhesive is ensured. Also in this case, the thickness of the adhesive layer is sufficiently small and the refractive index is equal to that of the light guide 51, and the adhesive layer will be described as a part of the light guide 51. Light guide 51
A linear light source 52 such as a fluorescent lamp is disposed near one of the side end surfaces 51c.

In the display device of the present invention configured as described above, first, a part of the light from the linear light source 52 is directly reflected on the first reflecting surface disposed near the side end face 51c of the reflector 53. The light is reflected by the surface 53a and enters the light guide 51 from the side end surface 51c. The display surface 54a is guided in the direction of the end face 51d.
We illuminate each place. As is clear from the cross-sectional views of FIGS. 8 and 2, the cross-sectional structures of the light guide and the display are similar only on one side of the central axis of the second embodiment and on one side of the central axis of the first embodiment. In addition, the behavior of the light entering from the side end surface of the light guide is the same as that of the first embodiment described with reference to FIGS. 4 and 5, and the description is omitted here. In addition,
In the present embodiment, the light guide 51 has a flat plate shape, and the side end faces are 51c and 51d shown in the figure, as well as the side end face seen from the front in FIG. There is a plurality of side end surfaces, and one of the side end surfaces 51c is selected to project light. However, light may be projected to any side end surface, and light may be projected to a plurality of side end surfaces. You may. As long as this is the first embodiment of the cylindrical light guide described above, the light may be projected on any of the two side end faces, and the same applies to various embodiments described below.

Another part of the light of the linear light source 52 is reflected by the reflector 5.
The second reflection surface 53b disposed on the back side of the third display body 54
, And becomes light for irradiating the rear surface of the display body 54. The behavior of light emitted from the rear surface of the display 54 is the same as that of the first embodiment described with reference to FIG.

Regarding the illumination, the display 54 is basically illuminated from the front and the rear with respect to the first embodiment and the second embodiment.
Are similar. However, in the first embodiment, separate light sources are used for illumination from the front and for illumination from the rear, and in the second embodiment, both illuminations are performed by a single light source. Is the difference, but not the essential difference.

The description of performing both illuminations with a single light source is the same as in the seventeenth embodiment described later, and will not be repeated. The basic difference between the first embodiment and the second embodiment is the appearance of the display graphic. In the first embodiment, the displayed figure appears as an amplified image because the outer surface is curved, but in the second embodiment, since the outer surface is flat, the image is almost the same as the graphic on the display surface. Absent.

The back light display device of the light guide plate type described as the conventional example is similar to the second embodiment in that a flat light guide is used. So let's compare the two. In a conventional light guide plate type display device, the display is placed in front of the light guide, and the display surface and the light guide are not in close contact. Light emitted from the light guide is used as a light source to illuminate from behind the display, and transmitted light is viewed.

In the display device of the present invention, the display is placed behind the light guide, and the display surface is in close contact with the light guide without interposing a gas layer. There are two types of illumination: a reflective type in which light is projected toward the side end surface of the light guide, and the display surface is illuminated from the front to see reflected light. At the same time, there are two types of transmission and reflection, both of which are illuminated with light by total reflection on the outer surface and are also illuminated from the front as reflected light, and either one or both are applied. All of these illuminations illuminate the display surface from the front, which is fundamentally different from conventional light guide plate type illumination.

Next, an embodiment in which a part of the light guide is made of a liquid such as water will be described. FIG. 9 and FIG.
It is a third embodiment of the present invention having a structure in which a part of the hollow cylindrical light guide is changed to a liquid. FIG. 9 is BB
FIG. 10 is a cross-sectional view taken along a line CC in FIG.

FIG. 11 is a sectional view taken on line AA of the fourth embodiment in which a part of the light guide having a flat outer surface is a liquid. The third and fourth embodiments are different in that the light guide is made of two kinds of materials, but the basic shape of the light guide is the same as that of the first embodiment. Light sources other than the light guide are the same including their positions. The same applies to the relationship between the display and the light guide.

In FIGS. 9, 10 and 11, the hollow transparent containers 66 and 76 are made of glass or acrylic resin. The hollow transparent containers 66 and 76 have injection ports 68 and 78, and liquids 67 and 77 such as water are injected into the hollow portions from the injection ports 68 and 78. That is, the light guides 61 and 71 are formed by the hollow transparent containers 66 and 76 and the liquids 67 and 77 injected into the hollow transparent containers 66 and 76. The hollow transparent containers 66 and 76 include an outer wall portion 66a and 76a of the hollow transparent container, an inner wall portion 66b of the hollow transparent container,
76b, bottom portions 66c and 7 near the light sources 62 and 72
6c, a ceiling portion 66d, 76d remote from the light sources 62, 72 is provided. 9 and 10
The shape of the light guide 61 in this embodiment is a hollow cylindrical body as in the case of the first embodiment, and the shape of the light guide 71 in the fourth embodiment of FIG. 11 is the shape of the second embodiment. It is a rectangle as in the case of. In the third embodiment shown in FIG. 6, an outer surface 61a of a light guide 66, and a boundary surface 67 between the liquid 67 and the hollow transparent container 61 located near the outer surface 61a
a, a back surface 61b of the light guide, and a boundary surface 67 between the hollow transparent container 61 and the liquid 67 at a position close to the back surface 61b
b is a cylindrical surface that equalizes the position of the central axis. FIG.
In the fourth embodiment, the outer surface 71 of the light guide 67
a, a boundary surface 77a between the hollow transparent container 71 and the liquid 77 near the outer surface 71a, a back surface 71b of the light guide, and a boundary between the hollow transparent container 71 and the liquid 77 near the back surface 71b. The surfaces 77b are planes parallel to each other.

In the third and fourth embodiments, when the solid transparent hollow containers 66 and 76 and the liquids 67 and 77 have the same refractive index, it is equivalent to the case where they are made of a single material. It functions in the same way as the first and second embodiments described. Hollow transparent containers 66 and 76 and liquid 6
If the refractive indices 7 and 77 are different from each other, the light guide has a multilayer structure, and either refraction or total reflection of light occurs at the boundary surface, and the light is guided in the first and second embodiments. Slightly different form.

In the third and fourth embodiments, the light guide is provided with two light guides.
Due to the different materials, a new boundary surface of hollow transparent container-liquid and liquid-hollow transparent container is added. If there is a difference between the refractive indices of the materials on both sides at these boundary surfaces, either refraction or total reflection necessarily occurs. These boundaries affect the illumination of the display surface and the appearance of the displayed graphic.

First, the effect on illumination will be described. Light that is incident from a medium having a high refractive index to a medium having a low refractive index at an incident angle equal to or greater than the critical angle θ undergoes total reflection. Other light undergoes ordinary refraction and passes through the boundary surface to change the traveling direction of the light, but those having the same incident angle change in the same direction. In addition, the traveling direction does not suddenly change due to the difference in the incident angle, but changes continuously. Therefore, there is no problem from the viewpoint of guiding light to illuminate the display surface.

[0169] When the light directed to the display surface undergoes total reflection, the illumination efficiency decreases. Note that even if total reflection occurs in light traveling in the direction of the outer surface, the illumination efficiency does not decrease. The reason is that the totally reflected light can be used as light for illuminating the display surface.

One measure for preventing a decrease in illumination efficiency due to total reflection is to use a material having a higher refractive index for a layer closer to the display surface so that total reflection of light toward the display surface does not occur. . However, in this case, the critical angle on the outer surface where the amount of total internal reflection is to be maximized is reduced, and the illumination efficiency is reduced. It is difficult to select a material that satisfies these conditions and enhances the efficiency, and it is desirable to consider that a material having a difference in refractive index as small as possible comes into contact. Since the illumination performance is determined at the boundary where the critical angle is the largest, it depends on how small the ratio of the boundary layer having the largest refractive index ratio is.

When a material having a large refractive index is sandwiched by a material having a small refractive index and the boundary surfaces are parallel, light having an incident angle larger than the larger critical angle of either of the two boundaries is converted to a material having a large refractive index. Is trapped inside and becomes ineffective light.

In the third and fourth embodiments, the hollow transparent containers 66 and 76 are made of acrylic resin (refractive index 1.49), liquid 6
Outer walls 66a, 7 of outermost hollow transparent containers 66, 76 when water 7 (refractive index: 1.33)
Let's take a look at 6a. On the outer side surfaces 61a and 71a (critical angle of about 42.1 degrees), light having an incident angle of 42.1 degrees or more is applied to the boundary surfaces 67a and 77a with the waters 67 and 77 (critical angle of about 63.degree.).
At 2 degrees), light having an incident angle of 63.2 degrees or more is totally reflected. As a result, light having an incident angle of 63.2 degrees or more is confined in the outer walls of the hollow transparent containers 66 and 76. When total reflection occurs as in this example, the illumination efficiency decreases.

Naturally, the light in the range where total reflection does not occur is used for illumination, and the light invalidated by total reflection is reflected by a reflector placed near the side end surfaces of the light guides 61 and 71. In general, the light is reflected and converted into effective light again. By the way, the hollow transparent containers 66 and 76 are made of acrylic resin,
When the liquids 67 and 77 are water, sufficient performance is obtained as an illumination function.

Next, the way in which the display figure is seen by the observer will be described. In addition, the surface including the path of the light transmitting the display figure and the surface including the light path for illumination that is projected on the side end face of the light guide toward the opposite side end face are included. Mutually orthogonal. In addition, illumination light has a problem whether or not light directed toward the display surface undergoes total reflection. However, light that transmits a display figure to an observer is basically light directed to the outer surface, and total reflection occurs in illumination. The boundary surface has no problem with the light transmitting the display figure to the observer. Awareness of this is important for understanding.

In the case of the fourth embodiment in which the light guide 71 is a flat plate, the boundary surface added by forming the light guide 71 from a plurality of materials including the outer surface 71a and the display surface 74a is also included. Since light is transmitted at an angle almost perpendicular, refraction or total reflection at the added boundary surface does not affect the appearance of the display graphic. Therefore, there is no difference from the second embodiment.

In the third embodiment in which the outer surface 61a is a cylindrical surface, the boundary surface is a cylindrical surface, and the angle of incidence of light incident on each boundary surface is larger than that of a flat surface. Therefore, the condition of the boundary surface greatly affects the appearance of the display figure.

FIG. 12 is a view for explaining a third embodiment in which a hollow cylindrical body filled with a liquid in a container is a light guide, and is a cross-sectional view taken along a line CC perpendicular to the center axis. It is. Light emitted from one point P0 of the display surface 64a is applied to boundary surfaces 67b and 67 between the solid hollow transparent container 66 and the liquid 67.
7a, the points P1 and P2, and further, the path of light that is refracted at P3 of the outer side surface 61a and reaches the observer Z through the path e. It is assumed that the observer is sufficiently far from the outer side surface 61a, and the angle between the optical axis of the light exiting the outer side surface 61a and reaching the observer is sufficiently small. Note that the observer Z is on the left side of the figure and is omitted from the figure. Straight lines a, b, c, d
Is a straight line connecting the center point O and each of the points P0, P1, P2, and P3, and a straight line f is an optical axis connecting the observer Z and the center point O. The angle β is the angle between the path e and the straight line d, and also the angle between the optical axis f and the straight line d. η is the central angle between the straight lines d and c, φ is the central angle between the straight lines c and b, and τ is the central angle between the straight lines b and a. The angles δ, α, and λ are points P3, P2, and P on each boundary surface, which correspond to the path of light reaching the observer through the point P0 on the display surface.
1 is the angle of incidence. The image of the point P0 on the display surface 64a is indicated by P0 '. The point P0 'of the image is
It is given by the intersection of a straight line connecting 0 and a line connecting the observer and the point P3 on the outer surface when exiting the point P0 and passing through the point P3 on the outer surface to reach the observer. The point P0 can be regarded as the vertex of the object A of the arrow perpendicular to the optical axis, and the image P0 'can be regarded as the vertex of the image A' of the arrow also perpendicular to the optical axis.

Further, the radius of the display surface 64a is R,
The radius of 1a is m · R (a coefficient satisfying m> 1), the thickness of the outer wall 66a of the hollow transparent container 66 is Dso, and the inner wall 66 is
The thickness of b is shown as Dsi. In the following description, the refractive index is nL for the liquid 67 and ns for the outer wall 66a.
o, the inner wall 66b is nsi. Further, the refractive index of air is na.

In the system shown in FIG. 12, the condition that the light emitted from the display surface 64a at the emission angle ξ0 and the emission angle at the outer surface 61a becomes β0 is that the radius ratio m of the outer surface 61a to the display surface 64a is This is the case where the following expression is satisfied. The derivation of this formula is based on the supplementary explanation "How to see the display figure with a three-layered light guide"
Is described later. m = nsi · Sin (ξ0) / na · Sin (β0) (Equation 4) Equation 4 is determined only by the conditions of the outermost surface and the innermost surface, ie, the outer surface 61a and the display surface 64a. The effect is not affected by the layer sandwiched between the layers. Equation 4 is a necessary condition, not a necessary and sufficient condition. The meaning of the necessary condition is that even if the range satisfies Equation 4, ξ0 and β0 may not be able to take values freely, and are limited by other internal conditions. This limiting factor is the phenomenon of total reflection.

Next, a necessary and sufficient condition in consideration of total reflection will be described. The k-th boundary surface from the inside at which total reflection may occur with respect to light traveling from the display surface side toward the outer surface is referred to as an Sk surface. In order to set a condition under which total reflection does not occur on the Sk surface, the light guide is virtually divided at all the Sk surfaces. The light guide inside the Sk plane is called the k-th light guide, and the outside is called the (k + 1) -th light guide. Assuming that the emission angle of the Sk plane is ρk, the following equation must be satisfied for all k-th light guides. For the derivation of this equation,
Please refer to “How to see a display figure with a three-layer structure light guide” as a supplementary explanation. mk = n (k−1) · Sin ρ (k−1) / nk · Sin (ρk) (Equation 5) where mk is the innermost surface of the outermost surface of the kth light guide. And nk is the refractive index of the material in contact with the outside of the Sk plane.

In all Sk planes, with respect to the k-th light guide, Equation 5
Needs to be satisfied. When an initial condition is set for a certain k0th light guide and k is sequentially changed to obtain Sin (ρk) from Equation 5, if an irrationality of Sin (ρk)> 1 occurs, the set initial condition is Total reflection occurs on the Sk surface.
In this case, the incident angle on the Sk plane has already exceeded the critical angle θ. In this case, it is necessary to set new initial conditions, such as setting the incident angle of the Sk plane to the critical angle θ and setting the output angle to π / 2.

In the Sk plane, the incident angle is the critical angle θ, and the outgoing angle is π /
When Sin (ρk) is obtained from Equation 5 while further changing k as 2, the new Sk surface restricts the light path more strongly than the previous Sk surface when the irrationality occurs again. . That is, the incidence angle is the critical angle θ and the emission angle is π / 2 on the new Sk plane.
If the initial conditions are set again, the condition that total reflection occurs on the previous Sk surface does not occur. Therefore, the above operation makes it possible to find a total reflection surface that most strongly regulates the path through which light travels due to total reflection. Hereinafter, the S surface that most strongly regulates the limit of the light path is referred to as the S0 surface.

Here, regarding the S0 surface that regulates the limit of the light path, assuming that the refractive index of the material in contact with the S0 surface is ns and the emission angle of the S0 surface is ρs, it is necessary to satisfy Equation 5 for all k. The necessary and sufficient conditional expression can be expressed by the following two expressions. m1 · ns / nsi = Sin (ξ0) / Sin (ρs) (6) m2 · na / ns = Sin (ρs) / Sin (β0) (7) where ρs ≦ π / 2 Where m1 is the radius ratio of the outer surface to the S0 surface, and m2 is the radius ratio of the S0 surface to the display surface.

As described above, the necessary and sufficient conditions for exiting the display surface at an angle ξ0 and exiting the outer surface at an angle β0 have been clarified. As a display device, the image on the display surface is as large as possible, and it is desirable that the image be seen to be enlarged to a range where the outer surface is viewed with the maximum field of view. Further, it is desirable that an image can be formed in a wider range depending on conditions. Therefore, next, a condition for maximizing the field of view of the image is determined. It is how to increase Sin (β0) in Equation 7, and the conditions are summarized as follows. , B. It is. I. When ns / na ≦ m2 Sin (β0) can be maximized when Sin (ρs) = 1 can be satisfied. When this condition is applied to Expression 6, m1 ≦ ns
i / ns must be satisfied. When this condition is satisfied, if m2 = k1 · ns / na (k1 ≧ 1), the following Expression 8 is obtained. Sin (β0) represents the field of view of the image. Therefore, even if the radius of the outer side surface is increased to k1 times the radius ratio, the field of view of the image becomes 1 / k1 of the outer side surface, and the field of view of the image itself is not different from the optimum case. k1 = 1 / Sin (β0) (Equation 8) If m2 <ns / na To make β0 the maximum π / 2, Sin (β0) = 1,
Sin (ρs) = m2 · na / ns obtained from Expression 7 is calculated by Expression 6
To satisfy m1 · m2 <nsi / na. When this condition is satisfied, m1 · m2 = k2 · n
Assuming that si / na (k2 <1), the following equation 9 is obtained. Here, m1 · m2 is a radius ratio m of the outer surface to the display surface. If the outer surface is smaller than the optimum case for the display surface, the visible range of the display surface is reduced. k2 = Sin (ξ0) (Equation 9) , B. The appearance of the display surface will be described based on the above condition. The conditions under which the widest range of the display surface can be viewed as the image of the widest viewing range are as follows:
11) is satisfied. m2 = ns / na (Equation 10) m1 = nsi / ns (Equation 11) It is most suitable for the display device to satisfy this condition, but it is necessary to improve the installation conditions of the display device or the illumination efficiency. In some cases, it may be necessary to adopt a set value in which the radius of the outer surface deviates from the optimum condition determined by Expressions 10 and 11.

When the radius of the outer surface is increased, the range of the visual field of the image becomes narrower. Therefore, if the upper limit is about 80% of the case where the visual field is optimal, k1 = 1.25 from the equation (8). The limit is up to 1.25 times.

On the other hand, when reducing the radius of the outer surface,
Since the field of view of the image is kept at the maximum, the field of view of the image as a display device is not so severe as to be narrower than the maximum field of view on the outer surface. However, limitations are required due to the disadvantage that the advantage that the image appears closer to a flat surface is lost, and that the visible area of the display surface is narrowed. When the display surface appears to be the maximum, ξ0 = π / 2.
= Π / 6, from equation (9), k2 = 0.5
And the limit is 0.5 times the optimal case.

In the above, the case where the light guide has a multilayer structure has been described. Here is a summary of this. When the total reflection surface S0 that regulates the path of light from the display surface to the outer surface by total reflection exists between the outer surface of the light guide and the display, the radius Rc of the outer surface of the light guide is equal to the outer radius. The refractive index of the air in contact with the side surface is na, the radius of the display surface R, the refractive index of the material in contact with the display surface is nsi, the radius of the total reflection surface S0 that most strongly regulates is Rs, and the material of the material in contact with the outside of the total reflection surface S0. Assuming that the refractive index is ns, the following equations 12 and 13 are simultaneously satisfied or ns / na ≦ Rc / Rs ≦ 1.25 · ns / na (Equation 12) Rs / R ≦ nsi / ns (Equation 13) Or, Equation 14 and Equation 15 are simultaneously satisfied, and 0.5 · nsi / na ≦ Rc / R <nsi / na (Equation 14) Rc / Rs <ns / na (Equation 15) The total reflection surface that regulates the light path from the display surface to the outer surface by total reflection In the case where there is no space between the outer surface of the display and the display body, when the following equation 16 is satisfied, light exiting the display surface at an emission angle of about π / 6 can be observed, and the image formed by the display surface can be observed. Can be seen in a field of view that is about 80% or more of the field of view in which the outer surface is maximally visible. 1.25 · nsi / na ≧ Rc / R ≧ 0.5 · nsi / na (Equation 16) As long as the conditions described above are satisfied, the outer surface and the display surface are cylindrical surfaces. As in the first embodiment having a light guide whose central axes coincide with each other, an image to be formed is displayed on the display surface, rather than directly viewing the display surface or an enlarged display of the display surface on the outer surface. The curvature is larger than the outer side surface, it becomes more planar, and the scale generated when viewing the display surface at an angle is corrected. It can be observed up to a partial area on the back side.

Here, in the third embodiment, the hollow transparent container 66 is made of an acrylic resin (refractive index nsi = nso = 1.4).
9) An optimal condition will be obtained for a case where the liquid 67 is water (refractive index ns = 1.33). Note that the radius of the display surface 64a is 300 mm, and the thickness of the hollow transparent container 66 is 5 mm, which cannot be changed. The S surface is only one boundary surface between the inner wall 66b of the hollow transparent container 66 and water.
This S plane is the S0 plane. Rs / R = m1 = 305/3
00 = 1.017 <1.12 = nsi / ns. In this case, Expression 13 holds. Therefore, it is possible to derive the range of 405.7 ≦ Rc ≦ 454.3 from the formula 12, and 317.4 ≦ Rc <405.7 from the formulas 14 and 15, and collectively, 317.4 ≦ Rc ≦ 454. 3 (Equation 17), the minimum value of the emission angle exiting the display surface 64a can be limited to about π / 6, and at the same time, the field of view of the image on the display surface 64a is maximized on the outer surface 61a. Can be within about 80%.

The appearance of the display surface of the columnar display device has been described above. Next, the relationship between the light guide and the display surface, which is important in the present invention, will be described. In the present invention, the light guide and the display surface must be in close contact. The close contact state means that the light guide and the display surface are optically connected via a liquid or a solid without a gas layer interposed between the light guide and the display surface.
The refractive index of a gas such as air is close to 1, which is the refractive index of a vacuum, and can be approximated to 1.00 under conditions where a display device is normally used, whereas the refractive index of a liquid or solid of a light guide is However, no matter how small, 1.2 or more can be secured and used. That is, it is a close contact state that the display surface is in direct contact with the light guide without passing through a gas layer having a small refractive index, or is optically connected through a liquid or solid having a large refractive index.

In the case where the outer surface is a curved surface such as a cylindrical surface, if a gas layer having a refractive index substantially equal to that of air enters immediately near the display surface, the image of the display figure cannot be enlarged. This is the first reason for bringing the display surface into close contact with the light guide.

Consider a case where a “gas layer” having a small refractive index ng exists between the light guide having a large refractive index nv and the display surface. The condition that the light emitted from the outer surface of the “gas layer” at an angle ξ and emitted from the outer surface at an angle β0 is obtained from the necessary condition shown in Expression 4 as follows: m = nv · Sin (ξ) / na · Sin ( β0) (Equation 18) Here, m is the radius ratio of the radius of the outer surface to the radius of the outer surface of the “gas layer”, and na is the refractive index of air in contact with the outer surface. The limit here to see the image at its maximum size is
The angle ξ of light exiting the outer surface of the “gas layer” corresponds to the critical angle θ. Therefore, Sin (ξ) = ng / nv is substituted into Expression 18, and the following Expression 19 is established. m = ng / na · Sin (β0) (Equation 19) Since the refractive index ng of the “gas layer” is substantially equal to the refractive index na of air, m = 1 / Sin (β0), and m is increased. Then, it becomes smaller in inverse proportion to Sin (β0). This indicates that no matter how large the radius ratio m, the range of the image that can be seen by the observer is limited to the range of the visual field that looks at the outer surface of the gas. If this gas layer is very close to the display surface, it will not be possible to enlarge it beyond the size of the display surface even by using a light guide. However, if the material of this layer is sufficiently larger than the gas, m = ng / Sin (β0), and if the radius ratio m is selected to be approximately the same as ng, the image is enlarged to the extent that the outer surface is viewed almost tangentially. You can try.

Next, the second reason why the display surface is in close contact with the light guide will be described. When a “gas layer” is formed between the display surface and the light guide, the critical angle θ at the interface between the light guide and the gas becomes smaller, and the light passing through this interface and illuminating the display surface from the front side is reduced. The amount is to be reduced. This is a problem that occurs not only when the outer surface is a curved surface but also when the outer surface is a flat surface.

For example, if the light guide is acrylic (refractive index 1.4)
9) and the display surface, a thin layer of air (refractive index 1.0
0), the critical angle θ at the interface between the light guide and air
Is about 42.1 degrees. When the air layer is water (refractive index: 1.33), the critical angle θ is about 63.2 degrees. In the case of air, the incident angle is about 4 compared to the case of water.
Light from 2.1 degrees to about 63.2 degrees is extraly reflected. This means that the display surface is darkened at a position distant from the light source having a large incident angle, so that there is no point in using a light guide.
When the boundary surface between the outer surface of the light guide and the air is parallel, the light that has been totally reflected once on the outer surface and the boundary surface repeats reflection on both surfaces, reaches the side end surface, and is reflected on the display surface. You will not be able to reach it.

At the interface between materials having different refractive indices, total reflection necessarily occurs. However, in the case of solids, liquids, and solids and liquids, the refractive indices have relatively similar values. The critical angle θs is sufficiently larger than the critical angle θa in the case of gas, and the illumination efficiency is significantly improved as compared with the case of the boundary with the gas. If the boundary layer is solid or liquid and made of a material with a similar refractive index to the original light guide, this boundary layer is a part of the light guide, and the light guide becomes a composite and adheres to the display surface. You can think that you are doing.

In order to make the light guide and the display surface adhere to each other without interposing a gas layer, as in the first and second embodiments,
A method in which a display body drawn on paper or the like is attached to the back surface with a transparent adhesive or pressure-sensitive adhesive (hereinafter, adhesives or pressure-sensitive adhesives are collectively referred to as an adhesive or the like). As in the embodiment, there is a method of immersing a surface on which a display figure is drawn in a liquid forming a part of the light guide. However, simply placing the display body close to the back surface creates a narrow gap and does not achieve a close contact state.

One of the reasons for making a part of the light guide a liquid is as follows.
The light guide can be easily brought into close contact with the display surface. In particular, when water is used as the liquid, it is the cheapest, has high safety, and is excellent in handleability. In the case of water, if you use it for a long time,
It is necessary to prevent the growth of small animals such as algae or plankton, and measures such as using an aqueous solution of a bactericide such as calcium hypochlorite or sealing with distilled water become useful. Further, an aqueous solution in which a dye is dissolved may be used to color the water of the light guide.

Although there is no problem when the printed plastic sheet is immersed in water as a display, the display cannot be directly immersed in water if the display is a display such as a paper print. In such a case, a method of laminating a thin plastic material on the display is effective. As a laminate material, a double-layered film of polyester and polyethylene is well known.
Polyethylene is attached to the display surface as an adhesive. In this case, the polyethylene and the display surface are in optically close contact with the polyester interposed therebetween. This laminate forms a boundary layer and is a double layer of polyester and polyethylene. In this case, respective boundaries between the light guide and the polyethylene, between the polyethylene and the polyester, and between the polyester and the display surface are produced.

Although the case of immersing the printed matter of paper in water has been suggested above, it is suggested that alcohol, glycerin, silicone oil, or the like be used instead of water, or that a printing sheet be used instead of paper. When it is necessary to prevent the interaction with the liquid, it is only necessary to select an appropriate plastic material and an adhesive, and to laminate under conditions that ensure the adhesion.

Next, the outer surface of the light guide and the display surface are spherical.
A fifth embodiment in which the display surface is immersed in the liquid of the light guide will be described with reference to FIGS. FIG. 13 is a transparent perspective view. A spherical light guide 91 having a hollow portion 93 and a spherical light source 92 are provided. The hollow disk-shaped lid 99 has an opening 98.

FIG. 14 is a sectional view taken along the line DD passing through the center of the light guide shown in FIG. The light guide 91 includes a hollow transparent container 96 and a liquid 97. The hollow transparent container 96
It has a spherical outer wall 96a, a spherical inner wall 96b, and a cylindrical partition wall 96c.

The spherical outer wall 96a is formed of a transparent acrylic resin, and the spherical inner wall 96b is a semi-transparent light diffuser, for example, a surface of a transparent acrylic resin is roughened to provide a clouded light scattering surface. is there. This surface is a display surface 94a.
As a display figure is drawn. A liquid 97 is injected into a closed space surrounded by the spherical inner wall 96b and the spherical outer wall 96a, the cylindrical partition wall 96c, and the lid 99, thereby forming the light guide 91. Each of the spherical outer wall 96a and the spherical inner wall 96b has a shape in which a part thereof is cut in a plane, and the spherical outer wall 96a is connected to a hollow disk-shaped lid portion 99. The spherical inner wall 96b is connected to a cylindrical partition 96c, and the cylindrical partition 96c is connected to a hollow disk-shaped lid 99. The front surface of the cylindrical partition wall 96c has a spherical inner wall 96b.
As with the surface on the front side, there is a cloudy light scattering surface with rough small irregularities. Note that the spherical inner wall 96b is disposed so that the center thereof coincides with the center of the spherical outer wall 96a. A spherical light source 92 is placed in a hollow portion 93 formed by the spherical inner wall 96b and the cylindrical partition wall 96c such that the center of the light source 92 substantially coincides with the center of the spherical inner wall 96b.

The spherical display device according to the fifth embodiment can be placed on the ceiling of a building with the lid 99 facing upward, placed on the wall facing the wall, or placed on the floor or desk facing downward. How to put it in. In this spherical display device, the spherical inner wall 9
6b is immersed in the liquid 97, and the display surface 94a
Are in close contact with the light guide without a gas layer.

Any light that exits an arbitrary point on the display surface 94a and reaches the observer through the outer surface 91a passes through one plane including the observer, the center of the spherical outer wall 96a, and the center of the spherical inner wall 96b. On this plane, the spherical outer wall 96a and the spherical inner wall 96b are concentric. The radius ratio m of the concentric circles is the same for any path. Therefore,
The appearance of the display surface of the fifth embodiment is the same as that of the third embodiment which is a columnar display device. The difference is that in the third embodiment, the image is deformed on a plane orthogonal to the central axis, but in the fourth embodiment, the image is three-dimensionally deformed on any plane including the center. .

Next, a sixth embodiment which is a columnar display device in which a display body is immersed in a liquid of a light guide will be described with reference to FIGS. FIG. 15 is a BB cross-sectional view,
FIG. 16 is a CC sectional view. In both figures, the light guide 101 includes a columnar hollow transparent container 106 which is a solid such as glass or acrylic, and a liquid 107. The light source 102 that projects light onto the light guide 101 includes the light guide 10
1 is arranged near. The light guide 101 has a display surface 101a.
, A side end face 101c close to the light source 102, and the light source 10
2 is provided with a side end face 101d remote from the second end face 101d. Liquid 107
Is injected into the light guide 101 through the injection port 108. Inside of the light guide 101 into which the liquid 107 is injected,
The display body 104 is immersed. That is, the light guide 101 is
The light guide 101 is formed of a hollow transparent container 106 and a liquid 107 injected therein, and the shape of the light guide 101 is a column. The difference from the third embodiment is that the inside of the light guide from the center axis is hollow. The only difference is whether it is or not. However, the outer surface of the light guide is a cylindrical surface as in the third embodiment.

The display 104 is a thin sheet having a surface covered with a coating material. This is wound in a cylindrical shape with the display surface 104a facing the outer surface 101a,
Align the central axis of this cylinder with the central axis of the light guide 101,
It is immersed in the liquid 107 injected into the hollow transparent container 106.

The sixth embodiment is different from the third embodiment only in that the inner wall of the hollow transparent container is eliminated and the adhesive layer is changed to a coating material. In particular, when the coating layer is thin and the refractive index is relatively close to the refractive index of the liquid, it may be considered that the liquid approximately directly adheres to the display surface. In the third embodiment, the display surface is in close contact with the back surface of the light guide with an adhesive or the like. However, as in the sixth embodiment, the liquid of the hollow cylindrical light guide is used. It is also possible to immerse a thin cylindrical display body in the inside.

The seventh embodiment will be described with reference to FIGS. 17 and 18 as another example of a display device in which a display body is immersed in liquid. 17 is a sectional view taken along the line BB, and FIG. 18 is a sectional view taken along the line CC shown in FIG. This display device is similar to the third embodiment described with reference to FIGS. The difference is that a cylindrical innermost wall 116 having a small radius is further inside the inner wall 66b of the hollow transparent container 66.
c, and a gap between the innermost wall 116c and the inner wall 66b of the hollow transparent container 66 is filled with the liquid reservoir 11 for immersing the display body 64.
It is set to 8. The light guide 111 including the liquid reservoir 118
Is formed. The reservoir 118 has a bottom 119,
There is no ceiling, and after inserting the thin sheet-shaped display body 64, the lid is closed by pushing an elastic body such as a string-like rubber. In both figures, an elastic body for covering the display body 64 and the liquid reservoir 118 is not shown. In the seventh embodiment,
Obviously, it has a function similar to that of the third or sixth embodiment.

Next, a flat display device having a liquid reservoir for immersing a display body will be described as an eighth embodiment with reference to FIG. FIG. 19 is a sectional view taken along the line AA, and FIG.
Is similar to the fourth embodiment described with reference to FIG. The difference is that a flat innermost wall 126c is provided further outside the inner wall 76b of the hollow transparent container 76,
c and the inner wall 76b of the hollow transparent container 76
4 is a liquid reservoir 128 for immersion. The light guide 121 including the liquid reservoir 128 is formed. The liquid reservoir 128 has a bottom portion 129, but has no ceiling. After inserting the thin sheet-shaped display body 74, the lid is closed by pushing an elastic body such as a string-like rubber. In FIG. 19, the elastic body for covering the liquid reservoir is not shown. In the eighth embodiment,
Obviously, it has a function similar to that of the fourth embodiment.

In the seventh and eighth embodiments, a wall is provided inside the light guide, in which the liquid is injected into the hollow transparent container, along the back surface, and the wall is connected to the light guide. The space formed between them is a liquid reservoir for immersing the display body. The liquid injected into the hollow transparent container and the liquid injected into the liquid reservoir may be the same or different. Also, the part of the light guide consisting of a hollow transparent container is
A light guide made of a single material, like the light guide of the first or second embodiment, may be used.

In each of the seventh, eighth, and twelfth embodiments described below, the light guide has a thin sheet-like display body and a rear surface adapted to the installation shape of the display body. And a wall provided along the back surface of the light guide, and a space is formed as a dedicated liquid reservoir for immersing the display body. For this reason, the shape of the display is determined by the shape of the liquid reservoir, and the creation of the display is facilitated. Also, replacement of the display body is facilitated.

Next, illumination will be described. The present invention
It has the following features regarding the illumination of the display surface. (1) Illumination from the front can be performed in a relatively narrow illumination space. (2) The illumination from the front is inevitably performed by the total reflection on the outer surface only by the illumination from the back, and a more attractive display device using the illumination from the front and the back together is obtained. (3) Active front illumination and back illumination can be used together in a narrow illumination space, and a clearer and more vivid display device can be obtained. In addition, the brightness of the display surface can be made more uniform by using both illuminations together.

[0212] Illumination by the intrinsic light source can be divided into two types, as is clear from the description of the embodiments. One is to illuminate the display surface of the display from the front,
Illumination means for projecting light toward the side end surface of the light guide (hereinafter, abbreviated as "illumination method from the front"), and the other one emits light toward the back side of the display. Lighting means (hereinafter,
This is abbreviated as “backside lighting method”). When the light source is included in the display device, one or both of the light sources are used.

In the embodiment described so far, the embodiment using only the “lighting method from the front” is shown in FIGS.
A sixth embodiment shown in FIG. 17, a seventh embodiment shown in FIGS. 17 and 18, and an eighth embodiment shown in FIG. Next, two methods for making the brightness of the display surface uniform in these “lighting methods from the front” will be described.

The first method is a method of disposing the display surface and the outer surface at an angle. This will be described with reference to FIG. FIG. 20 shows the outer surface 1 parallel to the light guiding direction.
This shows a case where the display surface 134a is inclined by an angle δ with respect to 31a. Here, the inclination angle δ is positive when the display surface 134a faces more toward the light source and negative when the display surface 134a is farther away. The display surface 13 of light having a solid angle ω (light corresponding to the path i shown in FIG. 4) that directly exits from the light source at one point Q and directly reaches the display surface 134a.
The range for illuminating 4a illuminates the area of area s when the inclination is + δ, but illuminates an area s' larger than s when the display surface 134a is parallel to the outer surface 131a.
That is, the irradiation amount per unit area of the display surface 134a increases due to the positive inclination. Conversely, when the tilt angle is negative, the irradiation amount per unit area of the display surface 134a decreases. However, after reflection on the outer surface 131a, the display surface 1
The light reaching the light-receiving portion 34a (light corresponding to the paths j and k shown in FIG. 4) is only light having an emission angle larger than the critical angle, and the inclination angle δ of the display surface 134a is inclined to the critical angle θ or more. Also, the tilting effect is reduced. When the outer surface 131a and the display surface 134a are parallel to each other, invalid light (path h shown in FIG. 4) that does not reach the display surface 134a and exits from the side end surface located at a position away from the light source. Light equivalent to
However, when the display surface 134a is tilted with respect to the outer surface 131a, the display surface 134a directly reaches the display surface 134a.

As is clear from the above description, the amount of light per unit area of the display surface can be controlled by tilting the outer surface and the display surface of the light of the paths i, j, and k shown in FIG. Also, the light on the path h can be used as effective light if it is tilted positively. In order to make the brightness of the display surface uniform, it is necessary to change the inclination as the distance from the light source increases. At a constant inclination, the ineffective light that escapes from the side end surface of the light guide can be used, and the whole becomes brighter, but the effect of uniformity is small. On the other hand, the brightness is made more uniform by increasing the angle at which the display surface is inclined toward the outer surface as the distance from the light source increases. It is the easiest and most effective method to experimentally determine the tilt angle for each display device.

It is easy to think that inclining the display surface with respect to the outer surface is relatively equivalent to inclining the outer surface to the display surface. The incident angle of the arriving light gradually decreases, and the degree of light that all the light in the paths i, j, k, and h shown in FIG. Absent.

As a display device in which the display surface is inclined with respect to the outer surface, the ninth embodiment and the tenth embodiment are described.
This will be described with reference to FIGS. 21 and 22. Both figures are AA sectional views on a plane perpendicular to the length direction of the linear light source 142. In both figures, the light guide 141 is a linear light source 142.
It is shown with In these embodiments, the light guide 1
The outer side surface 141a of the 41 is a flat surface, and the back side surface 141b to which the sheet-like display body is attached is such that the inclination angle becomes stronger in the positive direction with respect to the outer side surface 141a as the distance from the linear light source 142 increases. Is configured. FIG.
Is the inclination angle of the linear light source 142 very close to zero,
A ninth embodiment in which the tilt angle is gradually increased in the positive direction is shown. FIG. 22 shows that the inclination of the negative angle is extremely close to the linear light source 142, and the degree of the negative inclination angle is gradually reduced as the distance from the linear light source 142 is increased. This is a tenth embodiment in which the inclination angle is increased in the direction.

In these embodiments, the sheet-like display is stuck, but the display figure may be drawn directly on the inclined back surface of the light guide. Angle of display surface to outer surface δ
The point tilted only appears to a sufficiently far observer to be scaled to cos (δ). The distortion due to this scale can be corrected by drawing a figure enlarged at a magnification corresponding to the compression ratio. Or,
Considering that there is a limit to the tilt angle for making the illumination of the display surface uniform, there is also a method of limiting the tilt angle to such an extent that the compression of the figure is not bothersome. The specific degree of inclination may be determined according to the shape of the light guide.

In the ninth and tenth embodiments, the light guide 14
The outer surface 141a and the display surface 14 are changed by changing the shape of the display surface 14 itself.
This is an example in which 4a is inclined. When the light guide is formed in a unique shape, there are problems that the manufacturing cost of the light guide increases and that it is difficult to draw a display figure.

In the eleventh embodiment, a part of the light guide is made of a liquid, and a display body whose display surface is bent so as to have a desired inclination is immersed in this liquid. It is a shape display device. This flat display device will be described with reference to FIGS.

FIG. 23 is a perspective view showing a cut surface cut along the AA plane. FIG. 24 is a sectional view taken along line AA. In both figures, the sheet-shaped display 154 is formed by coating paper having a figure or the like printed on its surface with a plastic sheet. The display body 154 is fixed to the display body support 20 made of plastic, which is previously bent to a desired curved surface, and is immersed in the liquid 157. The light guide 151 in which the display 154 is immersed is similar to the light guide 71 of the fourth embodiment described with reference to FIG. Thus, the display 154 is attached to the liquid 157.
, The bent display surface 154a can be easily brought into close contact with the light guide 151.

Next, a twelfth embodiment of the display device of the present invention will be described with reference to the AA sectional view shown in FIG. In this display device, the liquid reservoir 1 is formed by a wall 166c on the back side of the light guide 161 whose back side surface 161b is inclined with respect to the outer side surface 161a.
68 is a flat panel display device. The reservoir 168 is
The thickness is set to such an extent that the display body 164 is inserted, and the rear side surface 161b of the light guide 161 is formed with a slope so that the display body 164 is arranged in advance with a desired slope.
By simply inserting the display body 164 into the liquid reservoir 168, the display surface 164a can have a desired inclination with respect to the outer side surface 161a.

Next, thirteenth and fourteenth embodiments of the cylindrical display device in which the display surface is inclined with respect to the outer surface as the distance from the light source increases, will be described with reference to FIGS. 26 and 27, respectively.

FIG. 26 is a sectional view taken along the line BB of the display device according to the thirteenth embodiment. In the figure, a light guide 171 and a light source 172 are shown. The outer side surface 171a is a cylindrical surface having the same radius, while the back side surface 171b is a light guide 171 in the shape of a trumpet tube whose radius increases with distance from the light source 182, and is made of acrylic resin. A circular light source 172 is placed near the thicker side end face 171 c of the light guide 171, and the side end face 171 is provided.
Light is emitted toward c. The display figure is drawn on the back side surface 171b, but is omitted in the figure. Display surface 174a
Are the same as the back side surface 171b, and both have a shape like a trumpet tube. Also, the outer surface 171a and the display surface 17
The central axis of 4a is at the same position.

FIG. 27 is a sectional view taken along the line BB of the display device according to the fourteenth embodiment. In the figure, a light guide 181 and a light source 182 are shown. This display device is the same as the display device according to the third embodiment described with reference to FIGS. The difference is in the shape and location of the display 184. That is, in the liquid 187 of the light guide 181 in the form of a hollow cylinder, a tubular display 184 in the shape of a trumpet tube, whose radius increases as the distance from the light source 182 in the circle, increases. And the display body 184 is aligned with the center axis thereof.

In the display devices according to the thirteenth and fourteenth embodiments, both sides thereof are symmetric with respect to the center axis in the BB sectional view. Looking at only one side, the relationship between the outer surface and the display surface is the same as that of the ninth embodiment of the display device described with reference to FIG. Is clear.

The ninth embodiment (FIG. 21), the tenth embodiment (FIG. 22), the eleventh embodiment (FIGS. 23 and 24), and the twelfth embodiment (FIG. 25) , And the light guide having the cylindrical outer surface shown in the thirteenth embodiment (FIG. 26) and the fourteenth embodiment (FIG. 27). In any case, the outer surface is straight with respect to the direction in which light is guided. That is, an illuminating means for projecting light to the side end surface of the light guide, a light guide in which the outer surface of the light guide is straight with respect to a direction in which the illumination light is guided, and a gas layer interposed in the light guide. When having a display body having a display surface that is in close contact with the display body, the display surface is inclined to the outer surface with respect to the light guiding direction, and the degree of the inclination is changed depending on the distance from the side end surface of the light guide, The brightness of the display surface can be controlled.

The first described with reference to FIGS. 26 and 27
The appearance of the display figure when the outer surface of the light guide is cylindrical and the display surface is inclined with respect to the outer surface as in the third and fourteenth embodiments will be described. In any of the embodiments, in a cross-sectional view cut along a plane orthogonal to the central axis, the outer surface and the display surface are concentric circles regardless of the cut position. However, the radius of the inner display surface changes depending on the cutting position in the Z direction. That is, since the radius ratio m varies depending on the location, the appearance of the image becomes complicated such that it is divided into the following three cases.

The first is a case where the radius ratio is equal to or smaller than the optimum condition at the portion where the radius ratio is the largest (the portion closest to the light source). In this case, in the z-direction along the central axis,
The image on the display screen can be spread out to the maximum extent on the outer surface everywhere and a columnar image resembling the cylindrical surface on the outer surface is created.

The second is that the radius ratio m is at an intermediate position on the z-axis.
Is the optimum condition, which is larger on the light source side and smaller on the opposite side. In this case, at a position distant from the light source, the field of view of the image on the display surface is narrower than the range in which the outer surface is fully viewed, and the image has a feeling smaller than the outer surface. In the vicinity of the light source, an image can be formed in a range where the image fully views the outer surface. In other words, the size of the image continuously increases from a position away from the light source to a position under the optimum condition.

The third case is that m is larger than the optimum condition at all positions. In this case, an image is formed in a range narrower than the range of the thickness of the light guide at all positions, and the shape of the image is similar to the shape of the display.

In general, as in the first case above,
It is advisable to set the radius ratio of the position closest to the light source to the optimum condition and to form a large image with the full size of the light guide. However, in order to attract people's interest, the display device often prefers unusual figures and images, and may be selected and configured depending on the application.

As is clear from the above description, FIG.
In the cylindrical display devices according to the thirteenth and fourteenth embodiments described with reference to FIG. 27 and FIG. The magnification of the image in the direction changes. This is a distortion of the image in the circumferential direction in a plane perpendicular to the central axis, which is not a problem when the outer side is a plane. Image distortion also occurs.

The distortion in the direction along the central axis is caused by tilting the display surface in the direction of the outer surface, and is the same as that of the ninth embodiment in which the outer surface is flat as described with reference to FIG.
At the position where the tilt angle is δ, the magnification of the image is cos (δ). This correction is easy, and it suffices if the displayed figure is enlarged to 1 / cos (δ). The reason why the magnification of the image in the circumferential direction changes is that the radius of the display surface changes depending on the position of the central axis. In order to correct this distortion, the radius of the display surface with respect to the position z of the central axis is obtained from the inclination angle δ, the enlargement ratio L is obtained from this, and a 1 / L-fold figure is drawn so as to correct this. good. These magnifications can be calculated using the basic formulas described later in “How to View Displayed Graphics with a Three-Layer Structure Light Guide” as a supplementary explanation.

Next, a description will be given of a second method of making the brightness uniform in the “lighting method from the table”. The second method is to insert a thin partition layer having a small refractive index between the outer surface and the display surface, and use the total reflection at the boundary between the partition layer and the light guide having a high refractive index to make use of a light source. This is to transmit light directly to a display surface at a position away from the display.

A fifteenth embodiment in which the second technique is applied to a flat panel display will be described with reference to FIG. FIG.
Is a sectional view taken along the line AA. Light guide 191 having a large refractive index
, Two partition layers 193a and 193b composed of a sufficiently thin air layer are provided on the display surface 1 from the outer side surface 191a.
It is inserted at a position distant from 94a. These partition layers 193a and 193b are parallel to the outer side surface 191a and partition the light guide 191 into three regions indicated by A, B and C. The display body 194 is adhered to the back side surface 191b with the display surface 194a facing. The partition layer 19
3a is a partition layer 19 having a height from 0 to La in the z-axis direction.
3b is arranged between the height 0 in the z-axis direction and Lb. The height of the partition layer is higher as it is closer to the outside of the light guide 191. In addition, the partition layer is embedded between two thin transparent sheets of plastic or the like, which are formed by dispersing spacers for determining the thickness of the air layer and bonding the periphery of the two sheets to each other. Formed.

When a part of the light guide 191 is liquid, it can be easily formed by immersing the sheet made as described above in the liquid. Note that the thickness of the air of the partition layer made of air is about 1 micron. The thicker one may be any thicker, but if it is unnecessarily thicker, there is a limit because the cross-sectional area of the light guide that guides light is reduced. Light source 19
In the portion of the side end face 191c close to 2, the outer face 19
It is appropriate to suppress the thickness from 1a to the display surface 194a to about 1/10 or less.

The light having entered the region A in FIG.
Until the above, total reflection is repeated between the partition layer 193a and the outer surface 191a. After the height La, the partition layer 193a disappears, and the light transmitted through the region A is reflected on the display surface 19.
4a. Thereafter, as is apparent from the above description, the light is reflected on the display surface 194a in all directions, a part of the light is emitted from the outer surface 191a, and becomes light for the observer to recognize the display surface 194a, and another part is light. Outer side 19
The light is totally reflected at 1 a and illuminates the display surface 194 a at a position further away from the light source 192.

The light that has entered the region B in FIG.
Until the above, total reflection is repeated between the partition layer 193a and the partition layer 193b.
Disappears and reaches the display surface 194a. Thereafter, up to the height La, total reflection is repeated between the partition layer 193a and the display surface 194a while illuminating the display surface 194a. Further, after passing the height La, the light becomes the same as the light transmitted through the region A.

The light that has entered the region C in FIG.
Up to this point, total reflection is repeated between the partition layer 193b and the display surface 194a, and after the distance Lb, the partition layer 193b disappears, and the light becomes the same as the light transmitted through the region B.

By introducing a partition layer as described above,
The light introduced into the light guide is guided to a direction away from the light source while repeating total reflection without hitting the light to the display surface to a certain height, and the display surface is illuminated from the place where the partition layer disappears. By appropriately selecting the regions A, B, and C as described above, the brightness of the display surface can be made uniform. The number of partition layers may be set according to the required uniformity. Further, in the fifteenth embodiment, the partition layer is parallel to the outer surface in the entire region, but prevents the light reaching the display surface from rapidly increasing where the partition layer is cut. for,
Near the end of the partition layer away from the light source, the partition layer is gradually inclined toward the outer surface, so that the light reaching the display surface can be gradually increased. The partition layer is a layer made of air, but may be any transparent gas.

The second method of making the brightness uniform in the “lighting method from the front” can be applied to the case where the outer surface is a curved surface. Thus, an image larger than the partition layer cannot be formed. Therefore, the application is limited, such as using this restriction as a special effect.

The "lighting method from the table" has been described above. Next, the “lighting method from behind” will be described. FIG. 13 shows an example in which only the “lighting method from behind” is applied.
Only the fifth embodiment shown in FIG. Further, as an embodiment in which the “lighting method from the front” and the “lighting method from the back” are used together, there are an example in which the light sources are separated in both methods, and an example in which one common light source is used. In the former,
The first embodiment shown in FIG. 1, FIG. 2 and FIG.
And a third embodiment shown in FIG. The latter includes the second embodiment shown in FIG. 7 and FIG.
There is a fourth embodiment shown in FIG.

When performing the “backside illumination method”, light from behind needs to be transmitted through the display. To this end, a translucent light diffusion layer is arranged between the light source and the display surface.
This translucent light diffusion layer may be the display body itself,
Paper or the like on which a display figure is drawn may be used. As seen in shoji paper, paper is translucent if it is thin to some extent and has the function of diffusing transmitted light in all directions. When the display forms a part of the light guide and the display screen is drawn on the front side, a translucent light diffusion sheet may be placed between the light source and the display. Further, the light diffusion layer made translucent here may be made transparent.

In the first and third embodiments in which separate light sources are provided for the “lighting method from the front” and the “lighting method from the back”, the first light source is a side end face of the light guide. And a second light source is disposed facing the back side of the display body and is exclusively disposed on the back side of the display body. It is the light source of the "lighting method from behind" that projects light toward the surface. In these examples, the second light source for the “backside illumination method” is a linear light source, which is placed at the position of the central axis of the cylindrical display body and the intensity of light illuminating the back side of the display body Are equal everywhere in the circumferential direction.

Next, a description will be given of a sixteenth embodiment using a “lighting from behind” method in which a plurality of light sources are arranged because a single light source is dark, with reference to FIG. FIG. 29 is a CC sectional view. In the first embodiment shown in FIG. 1, the center light source 13 is removed and a plurality of light sources 20 are newly added.
3a, 203b, 203c, 203d and 204e are arranged on the circumference to enhance the illumination from behind.
These five light sources are arranged at substantially equal intervals around the central axis, a light diffusion sheet 209 is placed between these light sources and the back surface 201d of the light guide 201, and light emitted from each light source is The luminous intensity distribution of light that is diffused by the light diffusion sheet 209 and impinges on the back side of the display body 204 is made more uniform.

The fixing portion 208 shown in FIG. 29 is a column for mechanically supporting each component such as the light guide 201 constituting the display device. In a display device using a hollow cylindrical body or a hollow cone as a light guide, if a fixed portion is installed in the hollow portion of the hollow light guide, the fixed portion that covers and covers the outer surface of the light guide from the outside can be eliminated, and the display content can be reduced. An excellent display device that does not shield the display can be configured.

The "lighting method from the front" and the "lighting method from the back" have been described above by taking as an example a columnar display device provided with a dedicated light source. Also in the flat display device, the first light source is arranged at a position facing the side end surface of the light guide, and the second light source is arranged at a position facing the back side surface of the display body. The light source may be composed of a plurality of light sources, or a light diffusion sheet may be disposed between the back surface of the display and the light source to make the luminous intensity distribution of the light hitting the back surface of the display more uniform. It can be easily analogized that it is the same as the case of the cylindrical display device.

When one of the light sources is removed in these embodiments, a display device using only the “lighting method from the front” or the “lighting method from the back” is obtained. Next, a single light source is called the “lighting method from the front” and the “lighting method from the back”
A configuration which also serves as a light source for the following will be described. First, the flat panel display will be described.

The second embodiment shown in FIGS. 7 and 8 and the fourth embodiment shown in FIG. 11 both use a part of the light emitted from one light source as a “lighting method from the front”. Next, an example of a flat-panel display device in which a part of the remaining light is used for the “backside illumination method” is the same for illumination. Here, the illumination of the second embodiment will be described with reference to FIG.

The first reflecting surface 53a (thick line in the figure) of the reflector 53 is disposed obliquely with respect to the side end surface 51c at a position facing the side end surface 51c of the light guide 51. The second reflection surface 53b (the thick line in the drawing) is disposed obliquely with respect to the back side of the display body 54 at a position facing the back side of the display body 54. Part of the light emitted from the linear light source 52 is transmitted to the first reflection surface 5.
The light is projected toward the side end face 51c of the light guide 51 by the reflection of the light 3a. The remaining part is projected toward the back side of the display 54 by the reflection of the second reflector 53b. Thus, one light source performs both the “lighting method from the front” and the “lighting method from the back”.

The direction of the linear light source 52 toward the linear light source 52 increases as the distance from the linear light source 52 increases, and the second reflective surface 53b of the reflector is curved to increase the degree of inclination with respect to the back side of the display member 54. It has a shaped shape. Thereby, the light illuminating from the back side of the display body 54 is strengthened at a position away from the linear light source 52, and the overall brightness of the display surface 54a is made uniform.

FIG. 30 is a sectional view taken along the line BB for explaining a seventeenth embodiment which is a columnar display device. In this cylindrical display device, a single light source serves both as a “lighting method from the front” and a “lighting method from the back”. The hollow cylindrical light guide 211 is formed by injecting a liquid 217 into a transparent container 216, and a cylindrical display 214 is immersed in the liquid 217. The display body 214 has a display figure printed on a paper that is a translucent diffusion sheet, and is coated with a plastic resin. Above the light guide 214, there are three donut-shaped light source groups of light sources 212d, 212e, and 212f. On the lower side, a light source 212
There are three donut-shaped light source groups a, 212b, and 212c. Opposing the ceiling part 216d of the transparent container 216,
The reflector 215 with the reflecting surface 215a facing the light source 212
d, 212e, and 212f. The reflecting surface 21 faces the bottom portion 216c of the transparent container 216.
The reflector 213 with the 3a facing the light source 212a, 212
b, 212c. These reflecting surfaces 215a and 213a are the first reflecting surface 53 of the second embodiment which is the flat display device described with reference to FIG.
corresponds to a and performs the same function. The reflection surface 215a reflects light from the upper light sources 212d, 212e, and 212f, and projects the light on the ceiling portion 216d of the transparent container 216. The reflecting surface 213a is connected to the lower light sources 212a, 212b, 21.
2c is reflected from the bottom portion 216 of the transparent container 216.
Light is projected on c. Of these light paths, the paths of the light from the lower light sources 212a, 212b, 212c are indicated by an arrow group A in the figure as an example. In the hollow portion of the light guide 211, a reflector 218 facing the back side of the display 214 is provided.
Is placed. The reflector 218 has a shape in which two trumpet-shaped tubes are connected to each other through a large opening. As the reflecting surface 218a of the reflector 218 moves away from the upper light sources 212d, 212e, 212f or the lower light sources 212a, 212b, 212c,
It has a curved shape that increases the degree of inclination with respect to the display body 214. The reflecting surface 218a is provided in the second embodiment, which is the flat display device described with reference to FIG.
It corresponds to the second reflection surface 53b and performs the same function. The reflection surface 218 a reflects light from three light source groups on the upper and lower sides, respectively, and projects the light on the back side of the display 214. Of these light paths, for example, the lower light sources 212a, 212
b, the path of light from 212c is indicated by arrow group B in the figure.

The reflecting surfaces 215a and 213a for the “lighting from the front” in the seventeenth embodiment are straight lines in the cross-sectional view, and are different from those in the “lighting from the front” in the second embodiment. Reflective surface 53a is a circular arc-shaped curve in the cross-sectional view, but there is no essential difference.
Any of the curves may be applied. The point is how to efficiently guide the light to the surface to be projected, which may be determined based on the positional relationship with the light source, ease of production, and the like.

In the seventeenth embodiment, the reflector 21
The reason why the shape of 8 is a trumpet shape is to make the brightness of the display surface 214a uniform. If it is not necessary to make the uniformity very large, a conical shape may be used, and the reflector 218 may be removed.

FIG. 31 is an eighteenth example in which the “lighting method from the front” and the “lighting method from the back” are applied to the flat display device.
It is an AA sectional view of an embodiment. The display body 224 is
The display drawing is drawn on the surface of the translucent light diffusion sheet. The first light guide 221 is in close contact with the display surface 224a without a gas layer. Second light guide 227
Are in close contact with the surface on the back side of the display surface 224a without interposing a gas layer. The light scattering / reflecting plate 228 is bonded to the second light guide 227 with a transparent adhesive so that the light reflecting surface 228a faces the second light guide 227 without passing through a gas layer. The first light source 222 is provided on one side end surface 221 of the first light guide 221.
c and one side end surface 227c of the second light guide 227 are located at positions facing both side end surfaces. The second light source 223 faces both side end surfaces of the other one side end surface 221d of the first light guide 221 and the other one side end surface 227d of the second light guide 227. Is in place. The reflector 225 reflects light from the first light source 222,
The light is reflected toward the side end surfaces 221c and 227c. The reflector 226 transmits the light from the second light source 223 to the side end surface 22.
The light is reflected toward 1d and 227d.

The side end face 221c of the first light guide 221
The light incident from 221d is, as already described,
The light is guided by the light guide 221 and illuminates the display surface 224a from the front. On the other hand, the side end surface 227 of the second light guide 227
c, 227d is incident on the second light guide 227
And illuminates the display 224 from behind. The system including the second light guide 227, the light scattering surface 228a, and the surface on the back side of the display body 224 is a light guide type surface light source, and the light scattering surface 228a and the back side of the display body 224 are provided. The light is guided to a place distant from the light source by, for example, repeating reflection with the surface.

In the eighteenth embodiment, both the “lighting method from the front” and the “lighting method from the back” use the light guide 221,
227, and the display surface 2 of the display body 224
24a and the back surface are the respective light guides 221 and 227.
The feature is that it is in close contact with. In particular, since the back surface of the display body 224 is in close contact with the second light guide 227, an unnecessary boundary layer with air or the like can be eliminated, and illumination from behind can be efficiently performed.

As a method of arranging the light guides in close contact with the front side and the back side of the display body, in addition to a method of connecting the light guides with an adhesive, a liquid liquid of an acrylic resin before polymerization is applied to the front side and the back side of the display body. Is disclosed in Japanese Patent Application No. 1-324330. Also,
The display and the light scattering reflector may be immersed in the liquid of the light guide in which the liquid is injected into the transparent container.

The embodiment shown here is for the case where the outer surface of the display and the light guide and the light scattering surface of the light scattering reflector are parallel to each other. You may arrange | position inclining.

As described above, with respect to the flat display device, the light guides are arranged in front of and behind the display, and the “lighting method from the front” is used.
And the lighting format using the "lighting method from behind" has been described. Even in the case of a hollow cylindrical display device, a similar illumination format can be realized. That is, a cylindrical display is placed at an intermediate position between the outer surface and the back surface of the hollow cylindrical light guide. The light scattering surface of the light scattering reflector is adhered to the back surface of the light guide. Then, when viewed from the display, the light may be projected toward the side end surface portion on the front side and the side end surface portion on the back side. It is not necessary to dispose a light scattering reflector on the back surface of the light guide as long as the light guide is used in a state of being symmetric with respect to the central axis. However, in the case where light is blocked by the hollow portion, it is preferable to increase the lighting efficiency by providing a light scattering reflector.

In the case of the sixth embodiment shown in FIGS. 15 and 16, the light guide 101 is placed before and after the display 104.
There will be. Therefore, the light source 102 is
6, a little further from the side end face 101c, and the side end face 10c.
Light is introduced from near the central axis of 1c. Furthermore, if the display body 104 is a translucent light diffusion sheet,
By disposing the light guides 101 before and after the display body 104, a display device having a "lighting method from the front" and a "lighting method from the back" is obtained.

As described above, the display made of a translucent light diffusion sheet, the first light guide that is in close contact with the display surface of the display without a gas layer interposed therebetween, and the display on the back side of the display. If the structure has a second light guide that adheres to the surface without a gas layer therebetween, and an illuminating unit that projects light toward at least one side end surface of the second light guide, the outer surface Irrespective of a flat surface or a curved surface, it is possible to illuminate from the back in the form of a light guide, it is possible to eliminate the need to arrange a light source on the back side of the display, and to realize a thin display device. In addition, the second light guide is in close contact with the rear surface of the display, so that the illumination efficiency is improved.

FIG. 32 is an AA sectional view for explaining a nineteenth embodiment of the display device of the present invention. This display device is a flat display device that can be observed from both sides. Rectangular box-shaped hollow transparent container 236
The light guide 231 is formed by the liquid 237 injected therein. The first display 234 and the second display 235 made of a translucent light diffusion sheet are immersed in the liquid 237. The first display body 234 and the second display body 235 are separated from each other with their back surfaces facing each other. The first display body 224 and the second display body 235 divide the liquid 237 into three regions. First display body 234
An area sandwiched between the first light guide 2311 and the second display body 235 is the first light guide 2311. Display surface 234 of first display body 234
The region sandwiched by the transparent transparent container 236a and the hollow transparent container 236 becomes the second light guide 2312. Display surface 23 of second display body 235
The region sandwiched between 5a and the hollow transparent container 236 becomes the third light guide 2313. The first light source 232 is connected to the side end surface 2321 c of the second light guide 2312 and the third light guide 23.
13 is located at a position facing the side end surface 2313c. Second
The light source 238 of the first light guide 2311
11d. The reflectors 233 and 23 surround the first light source 232 and the second light source 238, respectively.
9 are placed.

Light emitted from the first light source 232 is reflected by the reflector 2
33, the side end surfaces 2312c, 2312
13c, enter the second light guide 2312 and the third light guide 2313, and display the display surface 234a of the first display 234.
Then, the display surface 235a of the second display body 235 is illuminated. The light emitted from the second light source 238, together with the light reflected by the reflector 239, passes through the side end surface 2311d, enters the first light guide 2311, and enters the first display body 234 and the second display body 234. The display 235 is illuminated from behind.

The first display body 234 and the second display body 235 are not limited to the first and second display bodies 234 and 235 shown in FIG. In 237, it can be placed in a free position to some extent. For example, at least one of the first display and the second display may be rotated by 90 degrees in the yz plane. In addition, both display bodies 234 and 235 are arranged in parallel, the inclination is made gentle, and all of the first, second and third light guides 2311, 2312 and 2313 are connected to the first light source 232 and the second light guide 232. A configuration in which light can be guided from both of the light sources 238 may be employed.

Furthermore, the first light source 232 and the second light source 2
The arrangement position of 38 is not limited to the position shown in FIG.
The light source may be placed at a position facing the side end face on the near side or the far side with respect to the drawing. The nineteenth embodiment is characterized in that both the “lighting method from the front” and the “lighting method from the back” are placed on the side end surface side of the light guide having a small thickness, and the lighting space is small.

In the nineteenth embodiment, the liquid 237
To the first, second, and third light guides 2311, 2312, and 23.
13 has been described. However, a structure in which these light guides 2311, 2312, and 2313 are made of a solid such as acryl and adhered to the first and second display bodies 234 and 235 with an adhesive or the like may be used. Also, the second and third light guides 2
For 312 and 2313, the second light source is divided into a plurality of light sources,
They can be distributed separately.

Although various embodiments in which the outer surface of the light guide is planar have been described above, these embodiments are not necessarily limited to the planar shape, and even if the curved surface has a somewhat large radius of curvature. good. In the case of a curved surface having a somewhat large radius of curvature, whether it is a convex surface or a concave surface, the deformation of an image seen on the display surface is restricted to some extent, and a display figure can be recognized in a form approximately similar to a flat surface. Further, from the viewpoint of illumination, the light beam of the total reflection on the outer surface does not extremely converge or disperse, and can be used as illumination light with less unevenness. By the way, with respect to a curvature circle that is in contact with an arbitrary direction at an arbitrary point on the outer surface, the radius of curvature is more than twice the effective length of the outer surface along the direction. The display device can be regarded as an approximately planar display device. Manufacturing may be facilitated by allowing such a curved surface.

FIGS. 33 and 34 are views for explaining a twentieth embodiment of the display device of the present invention. FIG.
FIG. 3 is a perspective perspective view of a display device having a conical surface as an outer surface. FIG. 34 is a cross-sectional view taken along a line BB of a plane including the central axis of the conical light guide. The light source and the like are omitted.

A liquid 247 is poured into a hollow transparent container 246 having a conical shape, and cylindrical first, second, and third display bodies 242, 243, and 245 are immersed therein. The embodiment described so far, in which the outer surface is a curved surface,
All were cylindrical surfaces with a circle on a plane as a conducting wire, a straight line passing through the conducting wire and perpendicular to the plane as a generating line. However, in the twentieth embodiment, a circle on a plane is defined as a conducting wire, a straight line passing through the center of the circle and orthogonal to the plane is defined as a central axis, and a point on the central axis and separated from the plane is defined as It is a conical surface with a straight line connecting the conductors as a generating line.

By making the light guide a conical shape, stability in installing the display device can be obtained. In particular, in the case of forming a hollow transparent container with a flexible resin such as vinyl chloride or the like, when the large radius side is set as the lower part, the stability is further improved as compared with the case of a cylindrical shape. On the other hand, if the large radius side is set as the upper part, the display device can be easily seen by humans.

The appearance of the image of the circular surface with the conical outer surface is the same as that of the case where the outer surface and the display surface are cylindrical as far as each cross section is orthogonal to the central axis. However, since the radius of the outer surface changes according to the position in the central axis direction, the magnification of the image changes according to the position in the central axis direction.

In the twentieth embodiment, the three cylindrical display members 232, 233, and 234 have different display surface radii and coincide with the central axis. Are placed in agreement. Also, on any cross section orthogonal to the central axis of the three light guides, the radius ratio of the outer surface to the display surface is set to be equal to or greater than the optimum condition. As a result, the image of the display unit having a large radius is larger than the image of the display unit having a small radius, and three-dimensional display can be performed while maintaining the magnitude relationship between the three display units.

In the display device according to the twentieth embodiment,
Even if the shape of the light guide is changed from conical to cylindrical, if the radius of the outer surface and the display surface satisfies the above condition, three-dimensional display can be performed in the same manner while maintaining the magnitude relationship of the three display members.

In the twentieth embodiment, the display surface is constituted by three display elements having different radii. However, the display surface itself can be regarded as one display surface having a sharply changed radius.
Even if the radius continuously changes arbitrarily, if the radius ratio satisfies the above condition, it can be observed as a three-dimensional image similar to the shape of the display surface.

An example in which the radius of the display surface continuously changes is as follows.
It is a twenty-first embodiment of the display device of the present invention. This will be described with reference to FIG. A display body 254 having a barrel-shaped display surface 254a is arranged inside the cylindrical light guide 251 so as to be aligned with the center axis. When the radius ratio of the outer surface 251a to the display surface 254a is greater than or equal to the value of the optimal condition in each section perpendicular to the central axis, the display body 254
Image similar to the barrel-like shape can be observed. When a part of the radius ratio has a small value, the part appears to have the same shape as the cylindrical light guide 251. When the radius ratio becomes small in all cases, the entire display body 254 looks like the light guide 251 having a cylindrical shape.

This is because the outer surface has a cylindrical surface or a conical surface, the display surface has a rotational surface symmetric with respect to the central axis, and the central axis of the outer surface coincides with the central axis of the display surface. Holds for

[0279] The cylindrical surface and the conical surface are straight lines along the generatrix. Light is applied in the direction of this straight line, and the light is directed to a place away from the light source by using the total reflection. The light illuminating the display surface can be made uniform by increasing the parallelism of the light directed toward the. If the outer surface is curved in the direction in which the light is guided, even if parallel rays are applied, the brightness of the display surface can be increased or decreased due to the curved outer surface. This is not limited to the case where the conducting wire of the cylindrical surface and the conical surface is a circle, but also holds an arbitrary curve if the generating line is a straight line.

FIG. 36 is a view for explaining a display device according to the twenty-first embodiment of the present invention. The light guide 261 is
The outer surface 261a has a barrel shape and is curved with respect to the direction in which light is guided. The display body 264 has a cylindrical display surface 264.
It is a cylindrical shape having a. The display device according to the twenty-first embodiment is obtained by replacing the shape of the outer surface and the shape of the display surface of the display device according to the twenty-second embodiment. Also in this case, when the ratio of the radius of the outer surface 261a to the display surface 264a on the cross section orthogonal to the central axis is equal to or greater than the value of the optimal condition, an image similar to the shape of the display body 264 appears. When the size is small, the display surface 264a appears to have the same shape as the outer surface.

In this case, in the “lighting method from the front”, since the outer surface 261a is a curved surface in a direction in which light is to be guided, the outer surface 261a is illuminated with parallel rays to uniformly illuminate the display surface 264a. Things get harder. However, in the case of the barrel shape, a considerable degree of uniformity can be obtained by employing an illuminating means for irradiating light toward both side end surfaces.

In the embodiments described above in which the outer surface is a curved surface, a surface having the same radius around the central axis, such as a cylindrical surface, a conical surface, or a barrel-shaped surface, or a spherical surface symmetrical to the center point. . When the outer surface is symmetrical with respect to the central axis, the display body is also a display surface having the same radius from the central axis, and is a surface that is convex outward. In addition, the center axis of the outer surface and the display surface coincided with each other. When the outer side surface is a spherical surface, the display body is also arranged as a spherical display surface with the center of the outer surface and the center of the display surface coincident. This is because these embodiments are configured so as to look the same three-dimensionally or two-dimensionally from all directions. In the present invention, the outer surface of the light guide and the display surface of the display are allowed to have more free shapes than in the embodiments presented so far. That is, the outer surface may be any smooth curved surface or flat surface. In other words, a circle on a plane is used as a conducting wire, and either a columnar surface passing through a conducting wire and a straight line orthogonal to the plane as a generating line, or a conical surface passing through a conducting line and passing through a point outside the plane as a generating line. However, this conductor may be changed to an arbitrary curve. Furthermore, any curve may be used as long as it is a smooth curve apart from the concept of a conductor or a bus.

The display surface also needs a certain relationship with the outer surface, but has a high degree of freedom. Here, the conditions for the outer surface and the display surface will be described from both aspects of illumination and how the image is viewed. As described above, the present invention is characterized by illumination utilizing total internal reflection on the outer surface. First, the “lighting method from the table” will be described.

The presence or absence of total reflection is determined by the angle of incidence of each point on the outer surface with respect to the tangent plane. Therefore, when the curvature of the outer surface in the direction in which light is to be guided changes abruptly, the aspect of total reflection changes abruptly, and the display surface is partially shaded. In order to eliminate the partial shading of the display surface, it is necessary to make a straight line that does not change the curvature of the outer surface with respect to the direction in which the light is guided, or to make it a gradual monotone increase. However, in order to locally deform the image, there may be a case where irregularities are locally formed on the display surface. In such a case, the restriction on the outer surface is not absolute.

On the other hand, with respect to the display surface, in order to provide illumination without partial shading, the display surface is placed in a positional relationship substantially along the smooth outer surface, and the curvature of the display surface in the direction in which light is guided is adjusted. , It must be kept from changing rapidly. That is, it is desirable that the positional relationship between the display surface and the outer surface be kept constant or change gradually, in order to make the brightness of the display surface uniform. However, this is not a limitation when emphasizing the appearance of the image.

Further, the display surface has been described as an example of a smooth curved surface such as a cylindrical surface, a conical surface, or a barrel-shaped surface, but may be an arbitrary surface. Instead of a cylindrical or conical surface with a conductor as a circle or an arc and a straight line as a bus,
Any conductor can be used. The advantage of using a straight line for the generating line is when using the “lighting method from the front”, which is advantageous in making the brightness of the display surface uniform as described above. The method is also advantageous in terms of uniform brightness. When no illumination is performed, that is, when the display surface is used in a bright place in the daytime when the display surface is illuminated from all directions, the shape of the display surface is more free, and attention should be paid only to the distance from the outer surface. Even in the case where there is an illuminating means, a display that gives a strong impression by giving a three-dimensional expression by providing a locally convex protrusion or a concave outside on a smooth display surface may be used. In this case, the unevenness of the light and shade is caused by the projections and depressions. However, the unevenness is local, and the unevenness itself can be used as one feature.

Next, regarding the distance between the outer side surface and the display surface,
At the position of the side end surface where the light is projected, an interval is required to guide the light from the light source into the light guide, and the required interval is determined by the relationship of the illumination means.

Next, the “lighting method from behind” will be described. The transmitted light is totally reflected on the outer surface, and this illuminates the display surface from the front. This effect is remarkable when light transmitted through a bright portion of the display surface illuminates a relatively dark portion around the display surface. The minimum distance L from the point on the display surface through which the transmitted light has passed to the point where the light is totally reflected on the outer surface and illuminates the display surface again is a distance d when the display surface and the outer surface are parallel, and a critical angle. Is represented by θ, L = 2 · d · Tan (θ) (Equation 20) Therefore, when the dark part and the bright part on the display surface are separated by more than this distance L, an effect of illuminating the display surface from the front by the “lighting method from behind” appears.
However, these are not problems of local individual points, but problems of the design of the entire display surface. If the symbol is small, the interval d may be small, but if the symbol is large, it is advantageous to increase the interval d.

Next, how the image is viewed will be described. The positional relationship between the outer surface and the display surface is largely related to how the image is viewed. If the outer side surface is a curved surface convex outward, the displayed image appears to be enlarged. Conversely, if the outer surface is a curved surface that is concave outward, the displayed image appears to be reduced in scale. The enlargement or reduction magnification of the image changes depending on the curvature of the outer surface, the positional relationship between the outer surface and the display surface, and the angle at which the observer views the outer surface. Also,
The image of the graphic on the display surface may be inverted up, down, left, and right. If the image appears to be inverted left and right or up and down from the viewpoint of the observer, the display contents cannot be correctly recognized. The condition under which the image is not inverted is the positional relationship between the outer surface and the display surface.

First, the case where the outer surface is outwardly convex will be described. The light exiting from the point P ′ on the display surface travels through the light guide, reaches the point P on the outer surface, and is refracted at the point P according to the law of refraction to reach the observer. In order for the point P 'on this display surface to be able to form an image in the correct positional relationship without inverting the top, bottom, left and right relations with other points on the display surface, the point P' must be located on the outer surface side from the focal point. There must be.

The focus is an optical axis which is a straight line parallel to the tangent of the curvature circle at point P through the center point of the curvature circle tangent to the outside surface at point P, and the light incident on point P is refracted at the outside surface. Is the point at which the paths of light traveling through the light guide intersect. As is well known, the position of the focal point changes depending on the incident angle of the incident light.

The path of the light exiting the point P 'on the display surface, reaching the point P on the outer surface, and coming out of the light guide, and reaching the point P on the outer surface from outside the light guide. The path of the light traveling through the light guide and reaching the point P 'on the display surface is the same. That is, there is reversibility. Considering that the point P on the outer surface can be viewed from all directions, in order for the graphic image on the display surface to be displayed correctly without being inverted up, down, left and right, any point on the outer surface of the light guide is required. It is necessary that the incident light from the camera intersects the display surface of the display body at a position on the outer side of the focus of the incident light. As a matter of course, the contact between the display body and the outer side surface must be crossed at a position distant from the outer side surface because the existence of the light guide loses its meaning.

Next, the case where the outer side surface is concave toward the outside will be briefly described. On a concave surface, the focal point is outside the display surface, and the image is not inverted up, down, left, or right. The extent to which the scale is allowed will limit the position where the display surface is placed. Even if it is separated by the focal length d0, the scale is reduced to at most 1/2.

FIGS. 37, 38 and 39 are views for explaining a twenty-third embodiment of the cylindrical display device according to the present invention. In the twenty-third embodiment, the position of the display surface with respect to the outer surface is variously changed. FIG. 37, FIG.
8 and FIG. 39 are BB sectional views of the cylindrical display device. Liquid 2 in a hollow transparent container 276 of cylindrical acrylic resin
In the light guide 271 into which the first display body 27 is injected,
4 and the second display body 275 are soaked. The first display body 274 and the second display body 275 are in the form of a sheet having a sufficiently small thickness, and have a semi-cylindrical shape having a semicircular horizontal section.
Each central axis coincides with the central axis of the light guide 271 and is rotatable about this central axis. First
The radius of the light guide 274 is slightly smaller than the inner diameter of the hollow transparent container 276, and the display figure is drawn on the inner surface. The radius of the second display body 275 is smaller than the radius of the first light guide 274, and display figures are drawn on both the inner surface and the outer surface.

The straight lines a and b indicate the limits that can be seen by the observer, and indicate the path in the light guide of the light emitted tangentially on the outer surface. Therefore, the straight lines a, b
Is the critical angle θ. Also, a, b
Is the focal point F0 of the light emitted tangentially on the outer surface.

FIG. 37 shows the first display body 274 and the second display body 274.
Is a state where the display body 275 is placed on the opposite side of the central axis when viewed from an observer who is distant on the right side in the figure. In this state, the range that can be seen by the observer is the two observation portions 274a on the inner surface of the first display body 274.
(Indicated by a dotted line in the figure. The same applies to the following observation parts.) And one observation part 275 on the inner surface of the second display body 274.
a. It can be easily understood from the above description that the observation portions 274a and 275a are observed while being enlarged.

FIG. 38 shows that the second display body 275
Shows a state rotated by π / 2 from the state shown in FIG. In this state, the range that can be seen from the observer is the observation portion 274a, which is a part of the inner surface of the first light guide 274, and the second portion.
Observation part 2 occupying slightly more than half of the outer surface of the display body 275
75b. The observation part 274b is the observation part 275b
Since it is closer to the focal point F0, the magnification is large, but the observation area is small.

FIG. 39 shows that the second display body 275
Shows a state further rotated by π / 2 from the state shown in FIG. In this state, the entire outer surface of the second display body 275 can be viewed by the observer as the observation portion 275c.
The first display body can be viewed at the observation portion 274b.

Strictly, the observer sees a part of both ends of the first display body 274 in FIGS. 37, 38 and 39 and both ends of the second display body 275 in FIG. Can be. Further, these two end portions hide the above-described observation portions. However, these two ends do not form a clear image that is strongly viewed obliquely. Moreover, it is not essential for describing the invention of the present application. Therefore, the description is omitted here.

As described above, in the twenty-third embodiment, the second display body 275 is rotated, but the first display body 274 may be rotated, or, of course, both display bodies may be rotated. May be. Although the center axis serving as the center of rotation has been described as being coincident, the center axis may be shifted as long as rotation is not hindered. Further, the shape is a semi-cylindrical shape, but may be any shape such as a flat shape or a waveform.

As described above, by rotating or shifting the axis of the rotation, the positional relationship between the display surface and the outer surface changes variously. Then, the image that the observer sees becomes rich. In order to easily change the positional relationship, a structure in which a part of the light guide is immersed in the display body as a liquid is extremely useful.

Further, even if the display body is not moved, for example, when the outer surface and the display body are symmetrical with respect to the center axis, if the center axes are displaced from each other, an image that can be seen depending on the position where the display device is viewed can be obtained. Changes and the image appears to change before, during and after the observer passes by the display.

In some embodiments described above, when the display has a central axis and is rotatable, the display is rotated around this axis to provide a wider range of display contents. It can be uniformly transmitted to the observer.

FIG. 40 is a cross-sectional view of a display device according to a twenty-fourth embodiment of the display device in which the light guide is formed of a part of a cylindrical body.
It is sectional drawing. In the twenty-fourth embodiment, the light guide 2
81 is a shape obtained by cutting a cylindrical body along the central axis.
That is, it has a semi-cylindrical shape whose central angle is π. The outer surface 281a of the light guide 281 made of acrylic resin is a semi-cylindrical surface. The display body 284 is at least partially translucent, and has a flat display surface 284a and a flat back surface 281a.
Is connected closely. On the back side of the display body 284, linear light sources 282 and 285 are placed. Reflector 3
Is disposed on the opposite side of the display body 284 across the linear light sources 282 and 285, and serves to reflect light from both light sources 282 and 285 toward the back side of the display body 274.

The twenty-fourth embodiment is designed to reduce the installation space, and the range of azimuths that can be observed is greatly increased as compared with the case of the flat plate type. It can be easily understood from the explanation so far.

The twenty-fourth embodiment has been described with the two linear light sources 282 and 285 placed behind the display 284. However, the shape may not be linear, and the installation position may be on the side of the light guide 281. Further, the light source is not necessarily required if the purpose is only to be viewed from a wide azimuth range in a sufficiently bright place or the like.

The shape of the light guide 281 does not need to be a semi-cylindrical shape, and may be a shape obtained by cutting a cylindrical body at an arbitrary position along a plane parallel to the central axis. In short, if the outer surface 281a is a smooth curved surface having a convex shape outward, the image can be enlarged. Further, in order to locally distort the image to make a noticeable display image, the outer surface 281a may have a locally concave curved surface. In this case, a partial brightness unevenness occurs on the display surface 284a, and the unevenness itself is an element that attracts human attention.

FIG. 41 is a cross-sectional view taken along the line CC of the display device using an LCD as a display. The light guide 291 is shown in FIG.
0 is the same as that of the light guide 281 of the display device according to the twenty-fourth embodiment described with reference to FIG. The light guide 291 and the display 294 as an LCD are brought into close contact with an adhesive 292 or the like.

FIG. 42 is a cross-sectional view of a display device using an LCD as a display body, taken along line CC. The difference from FIG. 41 is that
The contact surface of the light guide 301 to which the display 304, which is an LCD, adheres is the liquid 307. If the liquid crystal 307 has high resistance to the liquid 307 used, the end of the light guide 301 which is a solid portion and the display 304 may be brought into close contact with an adhesive or the like. However, if not very resistant, liquid 30
A transparent sheet 303 made of plastic or the like is sandwiched between the display unit 7 and the display body 304 and is adhered with an adhesive 302 or the like. Further, sealing may be performed using a rubber packing 305 and a fixing bracket 306 so that the liquid 307 does not leak.

Of course, a CRT display or a plasma display may be used instead of the LCD.
Furthermore, using a translucent screen as a display,
An image may be projected on the screen from behind.

In the above, some of the embodiments in which a part of the light guide is made of a transparent liquid have been described. Among them, in the embodiment in which the display is immersed in the transparent liquid, the opening for inserting the display is provided. It is necessary for a hollow transparent container and is made by putting a lid after putting the display body. The lid portion is omitted. Also,
In order to replace the display, a hollow threaded container may be provided with a threaded lid, and the display may be easily replaced by opening and closing the lid. This lid can be fixed by simply press-fitting it.

When the hollow transparent container is sealed in order to prevent the transparent liquid from evaporating or the like, a void may be provided in a part of the container as necessary in preparation for expansion of the transparent liquid due to a change in temperature. Is natural.

FIG. 43 is a diagram showing a B-type light source according to the twenty-fifth embodiment in which the light guide in the display device according to the third embodiment described with reference to FIG. 9 is divided into an objective part and a display part. It is -B sectional drawing.

[0314] The twenty-fifth embodiment is different from the third embodiment in that the light guide is composed of three types of parts, a display portion, an objective portion, and a liquid. The shape and the like are basically the same. The same applies to the relationship between the display and the light guide.

The light guide 61 having the same function as the light guide 61 in the third embodiment described with reference to FIG.
Is a light guide 431. The light guide 431
Are the display unit 432 and the display body 434 that the observer directly observes.
An object section 433 and a liquid 437 that come into close contact with each other are provided. The holding member 435 connects the display unit 432 and the objective unit 433, and holds the liquid 437 so as not to spill. The fixing portion 436 serves as a support for fixing the display device to the ground or the like. Fixed part 4
If the display device is large, it plays a role of preventing overturning, and if the display device is small, it helps to prevent theft. Moreover, since the fixing portion 436 is provided in the hollow portion of the light guide 431, the display content is not shielded.

FIG. 44 is a view showing a light guide in the display device according to the sixth embodiment described with reference to FIG. 15, which is divided into an objective section and a display section. -B
It is sectional drawing.

[0317] The twenty-sixth embodiment is different from the sixth embodiment in that the light guide is composed of two types of parts, a display section and an objective section. Is basically the same. The same applies to the relationship between the display and the light guide.

The light guide 441 in FIG. 44 plays a role similar to that of the light guide 101 in the sixth embodiment described with reference to FIG. The light guide 44
Reference numeral 1 includes a display unit 442 for direct observation by an observer and an objective unit 443 which is a liquid. Object part 443 which is liquid
By immersing the display body 444 in the display body 444,
And the objective section 443 are in close contact with each other. The surface of the liquid that is in close contact with the surface of the display body 444 facing the display unit is the object surface. Holding member 4 in the twenty-fifth embodiment
35 holds the liquid 437 so as not to spill by relatively connecting the display unit 432 and the objective unit 433, but the holding member 445 in the present embodiment is connected to the display unit 442, Object part 443 which is liquid
Hold.

The support portion 446 is for supporting the display body 444 at a predetermined position in the display device. In the twenty-fifth embodiment, the objective section 433 has also served to support the display body 434 at a predetermined position. In the twenty-sixth embodiment, the display body 444 is positioned in a liquid. In order to prevent change, the support portion 446 is used.
Is required.

Note that the second embodiment is different from the first embodiment in the second embodiment.
The same concept as that of the twenty-fifth embodiment or the twenty-sixth embodiment, that is, the concept of dividing the light guide into an objective unit and a display unit, and the like is applied to the fourth embodiment. Is within the scope of the present invention.

Finally, as a supplementary explanation, “how to see a display figure with a light guide having a three-layer structure” will be described. FIG.
Using the third embodiment shown in FIG. 2, the appearance of a display figure in a light guide having a three-layer structure is determined by the relationship between the exit angle of light exiting the display surface and the exit angle of light exiting the outer surface. explain.

First, a description will be given of a case where total reflection does not occur at two boundary surfaces 67a and 67b between the display surface 64a and the outer surface 61a. When the law of refraction is applied to each of the points P1, P2, and P3, the following equation is established. Sin (λ) / Sin (α + φ) = nL / nsi (Equation A1) Sin (α) / Sin (δ + η) = nso / nL (Equation A2) Sin (δ) / Sin (β) = n0 / nso (Formula A3) Here, nL is the refractive index of the liquid 67, nso and nsi are the refractive indexes of the outer wall 66a and the inner wall 66b of the hollow transparent container 66, and na is the refraction of air in contact with the outer surface 61a. Rate. Dso and Dsi are the thickness of the outer wall 66a and the inner wall 66b of the hollow transparent container 66, respectively. Triangle O
Regarding P2P3, if attention is paid to the perpendicular drawn from the point P2 to the facing side (straight line d), the following equation is established. ｛M · R− (m · R−Dso) · Cos (η) ETan (δ) = (m · R−Dso) · Sin (η) (Equation A4) With respect to the triangle OP1 P2, it faces from the point P1. Focusing on the perpendicular drawn down to the side (straight line c), the following equation holds. ｛(MR−Dso) − (R + Dsi) Cos (φ) ETan (α) = (R + Dsi) Sin (φ) (Equation A5) With respect to the triangle OP0P1, the side facing the point P0 (straight line b) Focusing on the vertical line, the following equation is established. ｛(R + Dsi) −R · Cos (τ) ETan (λ) = R · Sin (τ) (Equation A6) By transforming Equations A4, A5 and A6, (m · R−Dso) · Sin (δ) Cos (η) + Cos (δ) Sin (η) = mR Sin (δ) (Equation A7) (R + Dsi) Sin (α) Cos (φ) + Cos (α) Sin (φ ) = (M · R−Dso) · Sin (α) (Expression A8) R · Sin (λ) Cos (τ) + Cos (λ) Sin (τ) = (R + Dsi) Sin (λ) (Expression A8) A9) Here, the expressions (A7), (A8), and (A
9) By deformation, the following equation is obtained. m · R · Sin (δ) = (m · R−Dso) · Sin (δ + η) (Equation A10) (m · R−Dso) · Sin (α) = (R + Dsi) Sin (α + φ) (Equation A11) (R + Dsi) Sin (λ) = R · Sin (λ + τ) (Equation A12) The above-mentioned six expressions A1 to A3 and A10 to A12 are the basic expressions.

The point P3 on the outer side surface 64a is defined as having an outgoing angle of π /
For light emitted at an angle β0 of 2 or less, the following expression A13 is established from expression A3. Sin (δ) = na · Sin (β0) / nso (Equation A13) For light that exits the point P0 on the display surface 61a at an angle ξ0 with an emission angle of π / 2 or less, (λ + τ) = ξ0, and this is applied to equation (A12) to obtain the following equation A14. (R + Dsi) Sin (λ) = R · Sin (ξ0) (Formula A14) Next, from Formula A2 and Formula A11, (R + Dsi) · nL · Sin (α + φ) = (m · R−Dso) · nso Sin (δ + η) (Equation A15) From Equations A13 and A10, na · m · R · Sin (β0) = (m · R−Dso) · nso · Sin (δ + η) (Equation A16) From the expressions A1 and A14, (R + Dsi) · nL · Sin (α + φ) = R · Sin (ξ0) · nsi (Formula A17) By substituting the right side of Equation A17 for the left side of Equation A15 and the left side of Equation A16 for the right side of Equation A15, the following equation is obtained. m = nsi · Sin (ξ0) / na · Sin (β0) (Equation A18) This expression A18 indicates that the light guide 61 of the third embodiment is 3
Although it was derived in the case of the layer structure, the invention is not limited to the case of a solid and a liquid, but can be made of any material. It is easily understood that the present invention can be applied to the case of being composed of even more layers and to the case of two layers.

[0324] The resulting expression A18 is expressed by
By appropriately selecting the radius ratio m with respect to the display surface 64a, light emitted from the display surface 64a at an arbitrary angle β0 can be emitted from the outer surface 61a at an arbitrary emission angle ξ0. In addition, it shows that there is no effect of the layer interposed therebetween. However, the expression A18 is expressed by the display surface 64a
Is a necessary condition for the angle at which the light exiting at the angle ξ0 exits the outer side surface 61a to be β0, but not a necessary and sufficient condition.

Next, the necessary and sufficient conditions in consideration of total reflection will be described. When light travels from a material having a large refractive index to a material having a small refractive index, total reflection may occur at the boundary surface Lj. There may be a plurality of such boundary surfaces Lj, but it is necessary to prevent total reflection from occurring at these boundary surfaces.

In order to set a boundary condition so that total reflection does not occur at such a boundary surface, the boundary surface Lj is virtually set.
, And the divided light guides on both sides are referred to as a j-th light guide and a (j + 1) -th light guide, respectively. j are numbered in ascending order from the inside, and assuming that the emission angle of each boundary surface Lj is ρj, in each divided light guide,
The following equation holds. Regarding the first light guide, m1 = nsi · Sin (ξ0) / n1 · Sin (ρ1) (Equation A19) Arbitrary values from the second light guide to the (p−1) th light guide For the k-th light guide, mk = n (k−1) · Sin ρ (k−1) / nk · Sin (ρk) (Equation A20) For the last p-th light guide, mp = n ( p-1) · Sin ρ (p-1) / na · Sin (β0) (Equation A21) must be satisfied. Here, nk is the refractive index of the material in contact with the outside of the boundary layer Lk. Here, np = n0,
If na = nsi, ρp = β0, ρ0 = ξ0, then
Formula A19, Formula A20, and Formula A21 can be represented by Formula A20. That is, when Expression A20 is established, the display graphic is visible to the observer.

[0327]

As described above, according to the present invention,
The following effects are obtained. According to the first aspect of the present invention, since the display graphic is not inverted vertically and horizontally and is variously deformed according to the curved surface, the display graphic is easily noticeable.

According to the invention of claim 2, since the same light emitted from the light source illuminates the display figure many times due to total reflection on the outer surface, the display content can be further enhanced. The invention of claim 3 is
Since the display graphic is smoothly deformed, the display graphic without discomfort can be noticed. Furthermore, the light from the light source can be illuminated uniformly by approaching a parallel light beam.

According to the fourth aspect of the present invention, even if the observer moves around the outer surface, the displayed figure does not change suddenly due to the outer surface. Even if there is a change, since the image is gently changed, it is possible to easily recognize the displayed content while deforming the image to make it more noticeable. The light guide is
The shape is a cone, a hollow cone, a cone, a hollow cone, or a shape obtained by cutting out a part of the cone, which is easy to manufacture.

According to the fifth aspect of the present invention, since the image on the display surface is an image closer to a plane, the display contents can be easily recognized. In addition, since the amplification factor of the image becomes larger as the display surface is farther from the optical axis, the display figure at a position farther from the optical axis, which has been viewed more strongly and scaled, is corrected, and the degree of the scale can be reduced. The display image is easy to see. In addition, it is possible to see the back side of the display surface that can only be viewed by the observer moving and moving around, and it is possible to see a wider range of display contents at a time than when directly viewing the display surface I can do it. Also, the worst case is that the visible range of the display surface is about π
/ 6, so that the worst case view range of the image in the viewable range of the display surface can be suppressed to 80% of the maximum view angle in which the outer surface is viewed in the tangential direction. In addition, the appearance of the image becomes equal in a certain range around the central axis, and the direction in which the display device can be viewed can be widened. In particular, when the display surface is a cylindrical surface or a conical surface, the display surface can be viewed from a 360-degree azimuth around the light guide.

According to the invention of claim 6, since the same light emitted from the light source illuminates the display figure many times due to the total reflection on the display surface, the display contents can be further enhanced. The parallel rays are
Since the angle of reflection by total reflection becomes equal at any position on the outer side surface, control for making the brightness of the display surface more uniform becomes easier.

According to the seventh aspect of the present invention, it is possible to convert the image into a three-dimensional image closer to a plane and to view it. Also,
The manufacture of the light guide is easy. In the invention of claim 8, the display surface can be illuminated from the front by limiting the space for illumination to only the thickness of the light guide. In addition, since the light from the lighting unit that projects toward the back surface of the display body can be simultaneously illuminated from the back and from the front by total internal reflection of the display surface, the display content can be further reflected and the front It is different from just lighting or lighting from behind. In addition, the light incident in parallel is not extremely concentrated or dispersed, and the reflection angle due to total reflection falls within a certain range at any position on the outer surface, so that the display surface is more uniform. It becomes easy to control to illuminate with light.

According to the ninth aspect of the present invention, since the thin light guide is disposed in close contact with the front and rear of the display, the display with the thin illuminator can illuminate the display from behind and in front. The device can be realized.

According to a tenth aspect of the present invention, by disposing thin light guides before and after the display, the two displays facing each other are simultaneously illuminated from behind and in front by a single illumination means. Therefore, it is possible to realize a display device with a small thickness for displaying a display figure on the front side and the back side with illumination.

According to the eleventh aspect of the present invention, an image on the display surface is formed as a three-dimensional image having a projection or a depression due to a projection or a depression. By expressing with, a strong impression can be given. In addition, the unevenness of the lightness and darkness due to the projections or depressions can be used as one expression means.

According to the twelfth aspect of the invention, the amount of light can be adjusted by changing the degree of inclination of the display surface with respect to the outer surface, so that the brightness of the display surface can be made uniform. In addition, naturally, light that directly reaches the display surface from the side end surface can be similarly adjusted. Further, it is possible to adjust the light that is illuminated from behind the display body, exits the display surface, is reflected by the outer surface, and returns. With these adjustments, the display surface can be more uniformly illuminated.

According to the thirteenth aspect of the present invention, it is possible to guide the light inside the light guide by limiting the exclusive light for illuminating the display surface far from the side end face into which the light is guided, and to guide the light away from the light source. Illuminate the display surface brightly to uniform the brightness of the display surface.

According to the fourteenth aspect of the present invention, since the light guide is a composite, the hollow transparent container and the transparent liquid can be separated in each process such as production and transportation. Further, since the transparent liquid is used as a part of the light guide, it can be manufactured at lower cost and the transportation cost is lower than when the whole is formed only of a transparent solid material such as acrylic resin or glass. In particular, when water is used as the liquid, the cost becomes extremely low. Further, by immersing the display body in the transparent liquid, the display surface can be easily brought into close contact with the light guide without passing through the gas.

According to the fifteenth aspect, the transparent liquid is easily available and inexpensive. In addition, micro-animals,
Since the propagation of aqueous plants such as algae can be suppressed, the display figure can be displayed stably over a long period of time. Further, the entire display content can be easily colored by the coloring agent, and the appearance of the entire display device can be easily changed.

According to the sixteenth aspect, inexpensive materials such as flexible vinyl chloride can be used. Further, depending on the shape of the light guide, manufacture and production are easy. In addition, it can be folded during the manufacturing process and transportation. Further, the manufacturing cost can be reduced, and an inexpensive display device can be provided. Further, unlike glass, the risk of breakage is further reduced.

According to the seventeenth aspect of the present invention, the display surface can be easily brought into close contact with the light guide without gas through by immersing the display in a transparent liquid. The position of the display body can be easily moved, and by changing the positional relationship between the outer surface and the display surface, the display image changes in a complicated manner, and a display device that attracts human interest can be configured.

According to the eighteenth aspect of the invention, the transparent resin or the transparent plastic sheet can secure the adhesion between the display surface and the light guide, and protect the display from the transparent liquid. According to the nineteenth aspect of the present invention, since the image of the display graphic changes with time, the display image changes in a complicated manner, and it is possible to configure a display device that attracts human interest.

According to the twentieth aspect of the present invention, the shape of the display can be determined and the light can be adhered to the light guide simply by inserting the sheet-like display into the exclusive liquid reservoir. This is convenient when the display body whose display content has been changed is frequently replaced. Transparent liquid inside the light guide can be semi-fixed or fixed in a sealed state, and when replacing the display,
This reduction of the transparent liquid can be eliminated.

According to the twenty-first aspect of the present invention, a single light source
Both the side end surface of the light guide and the back surface of the display can be illuminated. In addition, the size of the entire apparatus is reduced, and the reliability is improved.

According to the invention of claim 22, a fixing device for stabilizing the installation state of the device does not block the outer surface, and a display device excellent in display characteristics can be realized. Further, the size of the device can be reduced.

According to the twenty-third aspect of the present invention, since the object and the object surface of the object part can be easily brought into close contact with each other, the visible portion of the object observed by the observer can be protected from contact with other objects and the like. According to the invention of claim 24, the same light emitted from the light source illuminates the display figure many times due to the total reflection on the display surface, so that the display content can be further enhanced.

According to the twenty-fifth aspect of the present invention, the display body on which an image or the like to be observed by an observer is formed can be observed simply by bringing the display body into close contact with the objective surface of the objective section. According to the twenty-sixth aspect, the same light emitted from the light source illuminates the image of the display body and the like many times due to total reflection on the display surface, so that the display content can be further enhanced. Further, the display body on which an image or the like to be observed by the observer is formed can be observed simply by bringing the display body into close contact with the object plane of the objective section.

According to the twenty-seventh aspect, the same light emitted from the light source illuminates the display figure many times due to the total reflection on the display surface, so that the display content can be further enhanced. According to the twenty-eighth aspect, the display graphic is variously deformed by being enlarged or reduced in accordance with the curved surface, so that the display graphic is easily noticeable.

According to the twenty-ninth aspect of the present invention, since the display graphic is smoothly deformed, the display graphic without discomfort can be noticed. Further, the light from the light source is uniformly illuminated.
According to the 30th aspect of the present invention, since the display figure is three-dimensionally deformed smoothly, it is possible to draw the eye from a wide three-dimensional direction with the display figure without a sense of incongruity. Further, the light from the light source is uniformly illuminated. Further, the manufacture of the light guide is easy.

According to the thirty-first aspect of the present invention, the angle of reflection due to total reflection falls within a certain range at any position on the outer surface of the light incident in parallel without being extremely concentrated or dispersed. Therefore, it is easy to control the display surface to be illuminated with uniform light.

[0351] According to the invention of claim 32, the object to be displayed can be viewed regardless of its shape. In the invention according to claim 33, even if the observer moves around the outer surface, the displayed figure does not suddenly change due to the outer surface. Even if there is a change, since the image is gently changed, it is possible to easily recognize the displayed content while deforming the image to make it more noticeable. Also, the shape is easy to manufacture.

According to the invention of claim 34, it is possible to convert the image into a three-dimensional image closer to a plane and to view it. Also, it is easy to manufacture. Further, the light illuminating the display surface from the front is made uniform by total reflection.

[0353] According to the thirty-fifth aspect of the present invention, the sheet-like display body can be fixed in close contact with the object plane of the object part. In addition, it is easy to irradiate uniform light without abrupt changes to the display body that is in close contact with the object surface.

[0354] According to the invention of claim 36, since the displayed figure is not inverted upside down, left and right, the displayed figure can be observed without a sense of discomfort. According to the invention of claim 37, since the display body can be fixed at a fixed position, the display image is stable. In addition, since the entire display device can be fixed at a fixed position, it is possible to prevent the display device from falling or being stolen.

The invention according to claim 38 is inexpensive and easy to manufacture. Also, the weight can be reduced. The invention according to claim 39 can be easily manufactured and assembled.

According to the invention of claim 40, since a transparent liquid is easily available, a display device can be formed anytime and anywhere. In the invention according to claim 41, both the side surface of the display unit and the surface on the back side of the display body can be illuminated by a single light source. In addition, the size of the entire apparatus is reduced, and the reliability is improved.

[0357] The invention of claim 42 is based on the single light source,
It is possible to more reliably illuminate both the side surface of the display unit and the surface on the back side of the display body with a larger amount of light. According to the invention of claim 43, the display surface can be illuminated in a more uniform state by a relatively easy method of making the irradiated light closer to a parallel light beam.

According to the invention of claim 44, it is possible to display a display body which is easily available and has abundant expression contents including a moving image, in a more attractive manner. According to the forty-fifth aspect of the present invention, a display body that is easy to obtain and manufacture and has abundant expression contents can be displayed more attractively.

According to the invention of claim 46, a large number of display contents are
It can be changeable and eye-catching. According to the invention of claim 47, the display content can be more varied.

According to the invention of claim 48, it is possible to display projected display contents including a moving image. Claim 4
According to the ninth aspect, various shapes of display bodies can be displayed, and display contents can be abundant.

According to the fiftieth aspect, a display object that can be easily created can be a display object. According to the invention of claim 51, a display object for improving a lighting effect can be a display target.

According to the invention of claim 52, the display body can be easily replaced, and the reduction of the liquid can be suppressed. The invention according to claim 53 can provide a display device which is easy to assemble or manufacture. Further, the display body can be displayed brightly.

According to the fifty-fourth aspect of the present invention, the displayed graphic is enlarged without any inversion up, down, left and right, and is easily noticeable. According to the fifty-fifth aspect, a display graphic in a wider range is easily noticeable.

According to the fifty-sixth aspect of the present invention, the same light emitted from the light source illuminates the display figure many times due to total reflection on the display surface, so that the display content is further enhanced and the display body is displayed brighter and more clearly. I can do it.

According to the invention of claim 57, the display device can be safely stabilized. In addition, since the fixing portion for stabilizing the installation state of the device does not block the outer surface, a display device having excellent display characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment in which a hollow cylindrical body is used as a light guide.

FIG. 2 is a cross-sectional view passing through a central axis in the first embodiment in which a hollow cylindrical body is used as a light guide.

FIG. 3 is a cross-sectional view taken along a plane orthogonal to the central axis of the light guide in the first embodiment in which a hollow cylindrical body is used as a light guide.

FIG. 4 is a diagram for conceptually explaining a light path in the light guide according to the first embodiment.

FIG. 5 is a diagram illustrating a path of light reflected on a display surface of a display body.

FIG. 6 is a view showing the outer surface of the light guide and the display surface of the display body as cylindrical surfaces;
FIG. 7 is a diagram for explaining how an image is viewed in a case.

FIG. 7 is a perspective view of a second embodiment having an outer surface as a plane.

FIG. 8 is a sectional view of a second embodiment in which the outer side surface is a plane.

FIG. 9 is a cross-sectional view taken along a plane including a central axis in a third embodiment in which a hollow cylindrical body in which a transparent liquid is injected into a hollow transparent container is a light guide.

FIG. 10 is a cross-sectional view taken along a plane orthogonal to a central axis in a third embodiment in which a hollow cylindrical body in which a transparent liquid is injected into a hollow transparent container is a light guide.

FIG. 11 is a sectional view of a fourth embodiment in which a part of a light guide having a flat outer surface is used as a liquid.

FIG. 12 is a cross-sectional view taken along a plane perpendicular to the central axis of a third embodiment in which a hollow cylindrical body filled with a liquid in a hollow transparent container is a light guide. It is a figure for explaining image formation.

FIG. 13 is a perspective view of a fifth embodiment in which both the outer surface of the light guide and the display surface are spherical.

FIG. 14 is a cross-sectional view of a fifth embodiment in which both the outer surface of the light guide and the display surface are spherical, and a plane passing through the center is a cut surface.

FIG. 15 is a sectional view taken along a plane including a central axis in a sixth embodiment of a cylindrical light guide in which a display body is immersed in a liquid of a light guide.

FIG. 16 is a sectional view of a cylindrical light guide in which a display body is immersed in a liquid of a light guide according to a sixth embodiment, in which a plane orthogonal to a central axis is a cut surface.

FIG. 17 is a sectional view taken along a plane including a central axis in a seventh embodiment in which a liquid reservoir for inserting a display body is provided in a hollow portion of a hollow cylindrical light guide.

FIG. 18 is a sectional view taken along a plane perpendicular to a central axis in a seventh embodiment in which a liquid reservoir for inserting a display body is provided in a hollow portion of a hollow cylindrical light guide.

FIG. 19 is a cross-sectional view of an eighth embodiment having a flat light guide having a liquid reservoir for immersing a display body.

FIG. 20 is a cross-sectional view of the light guide for explaining the amount of light received on the display surface when the display surface is inclined with respect to the outer surface of the light guide.

FIG. 21 is a sectional view of a ninth embodiment in which a display surface is inclined with respect to an outer surface.

FIG. 22 is a sectional view of a tenth embodiment in which a display surface is inclined with respect to an outer surface.

FIG. 23 is a perspective view showing a cut surface in an eleventh embodiment having a flat outer surface formed by a method of immersing a display body having a display surface bent so as to have a desired inclination in this liquid and having a flat outer surface. It is.

FIG. 24 is a sectional view of an eleventh embodiment having a flat outer surface formed by immersing a display body whose display surface is bent so as to have a desired inclination in this liquid.

FIG. 25 is a sectional view of a twelfth embodiment having a liquid reservoir for inserting a display body on the back side of a light guide.

FIG. 26 is a sectional view of a thirteenth embodiment composed of a cylindrical light guide having a structure in which a display surface is inclined with respect to an outer surface.

FIG. 27 is a cross-sectional view of a fourteenth embodiment including a cylindrical light guide including a liquid having a structure in which a display surface is inclined with respect to an outer surface.

FIG. 28 is a cross-sectional view of a fifteenth embodiment in which a gas layer is disposed between the outer surface of the light guide and the display surface.

FIG. 29 is a sectional view taken along a plane orthogonal to a central axis of a sixteenth embodiment in which a column supporting a display device and a plurality of light sources are arranged in a hollow portion of a hollow cylindrical light guide.

FIG. 30 is a cross-sectional view in which a plane including a central axis of a seventeenth embodiment formed of a cylindrical light guide that combines a front-side lighting method and a back-side lighting method with a single light source is cut.

FIG. 31 is a cross-sectional view of an eighteenth embodiment in which a conventionally known light guide type illumination is applied to the illumination method from behind.

FIG. 32 is a cross-sectional view of a nineteenth embodiment of a display device in which a conventionally known light guide type illumination is applied to the backside illumination method and the display device is observed from both front and back directions.

FIG. 33 is a perspective perspective view in a twentieth embodiment having a conical surface as an outer surface.

FIG. 34 is a sectional view taken along a plane including a central axis of a conical light guide in a twentieth embodiment in which a conical surface is an outer surface.

FIG. 35 is a perspective view of a twenty-first embodiment in which the radius of the display surface changes continuously along the central axis.

FIG. 36 is a transparent perspective view of a twenty-second embodiment in which the radius of the outer surface of the light guide changes continuously along the central axis.

FIG. 37 is a sectional view of a twenty-third embodiment in which the position of the display surface with respect to the outer surface is changed with time.

FIG. 38 is a sectional view of a twenty-third embodiment in which the position of the display surface with respect to the outer surface is changed with time.

FIG. 39 is a sectional view of a twenty-third embodiment in which the position of the display surface with respect to the outer surface is changed with time.

FIG. 40 is a cross-sectional view of a twenty-fourth embodiment in which the light guide includes a part of a cylindrical body.

FIG. 41 is a sectional view of a twenty-fourth embodiment using an LCD as a display.

FIG. 42 is a sectional view of a twenty-fourth embodiment using an LCD as a display.

FIG. 43 is a cross-sectional view of the twenty-fifth embodiment in which the light guide in the display device of the third embodiment is divided into an objective part and a display part.

FIG. 44 is a cross-sectional view of the twenty-sixth embodiment when the light guide in the display device of the sixth embodiment is divided into an objective part and a display part.

FIG. 45 is a perspective view of a display device to which a well-known conventional technique is applied, in which a surface light source of a light guide plate type is used as a light source for back lighting.

FIG. 46 is a cross-sectional view of a display device to which a well-known conventional technique is applied, in which a surface light source of a light guide plate type is used as a light source for back lighting.

[Explanation of symbols]

 Reference Signs List 11 light guide 11a outer surface of light guide 11b back surface of light guide 11c side end surface of light guide 11d side end surface of light guide 12 first light source 13 second light source 14 display 14a display Display surface of 15 reflector

[Procedure amendment]

[Submission date] November 21, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

One of the reasons for making a part of the light guide a liquid is as follows.
The light guide can be easily brought into close contact with the display surface. In particular, when water is used as the liquid, it is the cheapest, has high safety, and is excellent in handleability. In the case of water, if you use it for a long time,
It is necessary to prevent the growth of small animals such as algae or plankton, and measures such as using an aqueous solution of a bactericide such as sodium hypochlorite or sealing with distilled water become useful. Further, an aqueous solution in which a dye is dissolved may be used to color the water of the light guide.

Claims (57)

[Claims] 1. A display device comprising: a light-transmitting light guide whose outer side surface is a convex curved surface; and a display body having a display surface facing the outer side surface. Incident light from an arbitrary point on the side surface is located closer to the arbitrary point than the focal point of the incident light, and intersects with the display surface of the display body at a position away from the outer surface; A display device, which is in close contact with the display surface without interposing a gas layer. 2. The display device according to claim 1, wherein the first illuminating unit that projects light toward a side end surface of the light guide and / or a surface of the display opposite to the display surface. A lighting unit having a second lighting unit for projecting light toward the display device. 3. The display device according to claim 1, wherein the light guide has, as a generating line, a straight line that passes through a conductor whose outer surface is a smooth curved line on a plane and is orthogonal to the plane. A columnar surface or a conical surface having a straight line passing through a point outside the plane through the conducting wire as a generating line, wherein the display body passes through a conducting wire whose display surface is a smooth curve on a plane. A display device comprising: a column surface having a straight line orthogonal to the plane as a generating line; or a conical surface having a generating line as a straight line passing through the conductor and passing through a point outside the plane. 4. The display device according to claim 1, wherein the light guide has a cylindrical shape, a hollow cylindrical shape, a centrally symmetric cone, a centrally symmetric hollow cone, and the like. A columnar body having a part of a conducting wire on a plane, an arc having a central angle smaller than 2π, and having a straight line passing through the conducting line and orthogonal to the plane as a generating line. A hollow columnar surface, and a convex pyramid surface with a line passing through the conductor and a point other than a point on the central axis perpendicular to the plane passing through the center of the arc and the line passing through the conductor. A display device comprising: a conical surface, a hollow conical surface that is the shape of the conical surface, or any of the above group of shapes. 5. A cylindrical body having an outer surface having a cylindrical surface, a hollow cylindrical body having an outer surface having a cylindrical surface, a conical body having an outer surface having a central axis symmetrical conical surface, and an outer surface having a central axis symmetrical shape. A hollow conical body with a conical surface, and a part of the conductor whose outer surface is on a plane is a circular arc having a central angle smaller than 2π and larger than π / 20, and a straight line passing through the circular arc and orthogonal to the plane is defined as a generating line. A columnar surface that is an outwardly convex columnar surface, a hollow columnar shape that is the shape of the columnar surface, a point other than a point passing through the center of the arc and intersecting with the plane on a central axis perpendicular to the plane. A pyramidal shape that is an outwardly protruding conical surface having a straight line passing through the arc as a generating line, a hollow conical surface shape that is a shape of the conical surface, or any of the above group of shapes;
And a light guide having a central axis symmetric single-layer or multi-layer structure made of one or more materials, and a display surface having a central axis symmetric rotation surface or a display surface having a central axis symmetric rotation surface. Π / 20 smaller than 2π at central angle
A larger portion, and the display surface is in close contact with the light guide without a gas layer interposed therebetween, and the central axis of the outer surface coincides with the central axis of the display surface; Radius R of the outer surface of the light guide at any cross section orthogonal to the central axis of
c, the refractive index na of the air in contact with the outer surface, the radius R of the display surface, the refractive index nsi of the material in contact with the display surface,
The relationship between the radius Rs of the total reflection surface S0, which is most strongly restricted, and the refractive index ns of a material in contact with the outside of the total reflection surface S0 restricts the path of light from the display surface to the outer surface by total reflection. When the total reflection surface S0 exists inside the light guide having a multilayer structure, the inequality A and the following inequality A are satisfied at the same time; And a display member installed at a position where E is satisfied when a total reflection surface that regulates a light path from the display surface to the outer surface by total reflection is not present inside the light guide. A display device characterized by the above-mentioned. ns / na ≦ Rc / Rs ≦ 1.25 · ns / na (inequality A) Rs / R ≦ nsi / ns (inequality B) 0.5 · nsi / na ≦ Rc / R <nsi / na ... (inequality C) Rc / Rs <ns / na ... (inequality D) 0.5 nsi / na ≤ Rc / R ≤ 1.25 nsi / na ... (inequality E) 6. The display device according to claim 5, wherein the light is emitted toward a first illumination unit that emits light toward a side end surface of the light guide and / or a rear surface of the display body. A display unit, further comprising: a lighting unit including a second lighting unit. 7. The outer surface is at least a part of a spherical surface,
And a light guide having a single-layer or multilayer structure having a central point symmetry made of a single material or a plurality of materials, wherein the display surface is at least a part of a spherical surface, and the display surface is formed without passing through a gas layer. A display device comprising: a translucent or transparent display body that is in close contact with the light guide; and illumination means including a point-like or spherical illumination unit. The display body includes a center of the outer surface and the display surface. And the radius Rc of the outer surface of the light guide at an arbitrary cross section passing through the center of the light guide, the refractive index na of air in contact with the outer surface, and the radius of the display surface. R, the refractive index nsi of the material in contact with the display surface, and the total reflection surface S that regulates the most strongly.
The relationship between the radius Rs of 0 and the refractive index ns of the material in contact with the outside of the total reflection surface S0 is determined by the total reflection surface S0 that regulates the path of light from the display surface to the outside surface by total reflection. In the case of a multilayer structure present inside the light body, the following inequality A
And B are set at the same time or C and D are set at the same time, and the total reflection surface that regulates the path of light from the display surface to the outer surface by total reflection is the light guide. The display device, wherein the display device is installed at a position where the condition that E is satisfied is not present inside the device. ns / na ≦ Rc / Rs ≦ 1.25 · ns / na... Inequality A Rs / R ≦ nsi / ns... Inequality B 0.5.nsi / na ≦ Rc / R <nsi / na... Inequality C Rc / Rs <ns / na inequality D 0.5 · nsi / na ≦ Rc / R ≦ 1.25 · nsi / na inequality E 8. A light guide having an outer surface that is flat or smooth curved surface, a display having a display surface facing the outer surface, and projecting light toward a side end surface of the light guide. A lighting unit including a first lighting unit and / or a second lighting unit for projecting light toward a back surface of the display body, wherein the display body includes the display surface. A display device having a predetermined distance from an outer side surface and being arranged in close contact with the light guide without interposing a gas layer. 9. A display comprising a translucent light-diffusing sheet or a transparent sheet, a first light guide adhered to one surface of the display without a gas layer therebetween, and A second light guide that adheres to the other surface without a gas layer interposed therebetween, and projects toward at least one of the side end surfaces of at least one of the first light guide and the second light guide. A display device, comprising: lighting means for emitting light. 10. A first display comprising a translucent light diffusion sheet or a transparent sheet, and a second display comprising a translucent light diffusion sheet or a transparent sheet.
And a first member that is closely attached to one surface of the first display member and one surface of the second display member without a gas layer therebetween.
And a second light guide having an outer surface facing the other surface of the first display body, the second light guide being in close contact with the other surface of the first display body without a gas layer therebetween. A third light guide, which is in close contact with the light body and the other surface of the second display body without a gas layer therebetween, and has an outer surface facing the other surface of the second display body; And a lighting means for projecting light toward at least one side end surface of the first light guide. 11. The display device according to claim 5, wherein the display body, the first display body, or the second display body is locally outside on a surface. Having a convex protrusion and / or a concave depression. 12. A light guide provided with an outer surface having a straight line group or a straight line group or a curved line group having a straight line group or a slope group parallel to a direction in which light is guided, and closely adhered to the light guide body without passing through a gas layer. A display device comprising: a display body having a display surface; and illuminating means for projecting light to a side end surface of the light guide, wherein a degree of inclination of the display surface with respect to the outer surface is determined by a side of the light guide. A display device that changes according to a distance from an end face of the display device. 13. A light guide having a flat or curved outer surface, a display having a display surface in close contact with the light guide without a gas layer therebetween, and a side end face of the light guide. A lighting device that projects light toward the display device; and a partition device that is separated from both surfaces between the outer surface and the display surface and has a gas layer. The display having a thickness smaller than one-tenth of a distance between the outer side surface and the display surface at a portion end face, a thickness larger than 1 micrometer, and the partitioning means at a fixed distance from the side end face side; A part of light directly projected on a surface is blocked. 14. The display device according to claim 1, wherein the light guide, the first light guide, the second light guide, or the third light guide is provided. The display device, wherein the body is a composite in which a transparent liquid is injected into a hollow transparent container. 15. The display device according to claim 14, wherein the transparent liquid is distilled water or an aqueous solution containing a bactericide or a coloring agent. 16. The display device according to claim 14, wherein the hollow transparent container is made of a flexible transparent resin. 17. The display device according to claim 14, wherein the display, the first display, or the second display is immersed in a transparent liquid. 18. The display device according to claim 17, wherein the display body, the first display body, or the second display body is formed of a transparent resin or a transparent plastic sheet without a gas layer. A display device characterized by being closely covered. 19. The display device according to claim 17, wherein the display, the first display, or the second display is the light guide, the first light guide, or the first light guide. 2. The display device, wherein the display device moves relative to the second light guide or the third light guide with time. 20. The display device according to claim 18, wherein the display body, the first display body, or the second display body is in a sheet shape, and the light guide is the display body or the display body. A dedicated liquid reservoir for immersing the first display or the second display, wherein the display or the first display or the second display is installed in the dedicated reservoir; A display device characterized by the above-mentioned. 21. A light-transmitting light guide, a display on which a display image is formed, a first reflecting means including a first reflecting surface facing a side end face of the light guide, and the display. A second reflecting means provided with a second reflecting surface facing one side of; and an illuminating means provided with an illuminating unit located at a position facing both the first reflecting surface and the second reflecting surface. A display device provided with the first reflection surface so that light emitted from the illumination means toward the first reflection surface is reflected toward a side end surface of the light guide. It is arranged obliquely with respect to the side end surface of the light body and the illumination unit, and the light emitted from the illumination means toward the second reflection surface is reflected toward one surface of the display body. A display device, wherein the second reflection surface is arranged obliquely with respect to one surface of the display body and the illumination means. 22. A part of a conducting wire on a plane having a hollow columnar shape, a hollow conical shape, and a plane having an arc whose central angle is smaller than 2π and a straight line passing through the arc and being perpendicular to the plane is defined as an outside line. A display device comprising: a light guide having a hollow columnar shape having a convex columnar surface as an outer surface; and a display unit; and a fixing unit for fixing the light guide. Wherein the fixing means is provided in a hollow portion of the light guide. 23. A display device that allows an object to be visible through transmission, comprising: an objective section having an object surface on which at least a part of the object is in close contact; and an opposite side to the object section with respect to the object section; A display unit having an outer surface for displaying the object through the objective unit. 24. The display device according to claim 23, wherein light is projected from one position to an object plane of the object section.
A lighting unit having a lighting unit and / or a second lighting unit for projecting light from the other position to the object plane. 25. The display device according to claim 23, further comprising: a display member that forms an image such as a character or a figure with an object that is in close contact with the objective surface. 26. The display device according to claim 23, wherein the first illuminating unit that illuminates the objective unit and / or the illuminating unit emits light from the side opposite to the first illuminating unit. A display device, further comprising: a lighting unit having a second lighting unit for performing the operation; and a display body for forming an image such as a character or a figure with an object in close contact with the objective unit. 27. The display device according to claim 26, wherein the light emitted from the first illumination unit and / or the light emitted from the second illumination unit is transmitted through the display unit and the objective unit. Light reflected from the outer surface and projected onto the objective section. 28. The display device according to claim 23, wherein the display unit generates a curvature circle at an arbitrary point on the outer surface on the same side of the outer surface. A display device characterized by the above-mentioned. 29. The display device according to claim 28, wherein the outer surface of the display unit is at least part or all of a cylindrical surface or a conical surface. 30. The display device according to claim 28, wherein the display unit has at least a part or all of a curved surface having an outer surface having a spherical surface or an oval shape. 31. The display device according to claim 28, wherein the display portion has a flat outer surface or a smooth curved outer surface. 32. The display device according to claim 23, wherein the objective section has an arbitrary shape. 33. The display device according to claim 32, wherein the objective portion has at least a cylindrical surface or a conical surface or a part thereof. . 34. The display device according to claim 32, wherein in the objective section, the objective surface is at least a part or all of a curved surface having a spherical or oval shape. 35. The display device according to claim 32, wherein, in the objective section, the display section has a flat shape or a smooth curved shape. 36. The display device according to claim 23, wherein incident light from an arbitrary point on the outer surface of the display unit is closer to the arbitrary point than a focal point of the incident light. Intersects with the objective surface of the objective section. 37. The display device according to claim 23, further comprising: a holding member that holds the objective unit by being connected to the display unit, wherein the objective unit is transparent. A display device characterized by being formed of a liquid. 38. The display device according to claim 23, wherein a hollow portion surrounded by the objective portion and the display portion is formed. 39. The display device according to claim 38, wherein the hollow portion contains a transparent substance. 40. The display device according to claim 39, wherein the hollow portion is filled with a transparent liquid. 41. The display device according to claim 24, wherein the first illuminating unit and the second illuminating unit are the same. . 42. The display device according to claim 24, wherein the reflection unit reflects light emitted from the first illumination unit and / or the second illumination unit. A display device, further comprising: 43. The display device according to claim 42, further comprising: a light scattering sheet that covers the first lighting unit and / or the second lighting unit. 44. The display device according to claim 25, wherein the display is a display device such as a CRT display device, a liquid crystal display device, or a plasma display device. Display device. 45. The display device according to claim 25, wherein the display body is in a sheet shape. 46. The display device according to claim 45, wherein the number of the display bodies is plural. 47. The display device according to claim 45, wherein the display is movable. 48. The display device according to claim 45, wherein the display is a screen. 49. The display device according to any one of claims 45 to 47, wherein the display body is formed with characters, figures, and the like by means of gaps, dents, projections, and the like. Display device. 50. The display device according to any one of claims 45, 48, and 49, wherein the display body is configured to draw characters, graphics, and the like. 51. The display device according to claim 44, wherein at least a part of the display is transparent or translucent. 52. The display device according to any one of claims 23 to 51, further comprising a dedicated liquid reservoir for installing a display for forming an image such as a character or a figure. Display device. 53. A display unit at least partially formed of a transparent cylinder, a holding member for closing an end of the display unit so that liquid can be stored inside the display unit, and a display to be displayed on the display unit A display device, comprising: a support portion for supporting a body inside the display portion. 54. The display device according to claim 53, wherein at least a part of an outer periphery of the display unit is circular or elliptical, and a thickness of the display unit is smaller than a radius of the outer periphery. Extremely small, the support portion supports the display body on which a planar image is formed, so that the display body can be immersed in water stored inside the display portion while remaining flat or cylindrical, and The ratio of the radius of the outer periphery to the value obtained by subtracting the distance between the outer periphery of the display unit and the display body from the radius of the outer periphery is set at a position where the ratio of the radius of the outer periphery is equal to or less than the refractive index of the stored liquid. A display device characterized by the above-mentioned. 55. The display device according to claim 53, wherein at least a part of an outer periphery of the display unit is circular or elliptical, and a thickness of the display unit is smaller than a radius of the outer periphery. Extremely small, the support portion supports the display body on which a planar image is formed, so that the display body can be immersed in water stored inside the display portion while remaining flat or cylindrical, and The ratio of the radius of the outer periphery to the value obtained by subtracting the distance between the outer periphery of the display unit and the display body from the radius of the outer periphery is set to a position where the ratio of the radius of the outer periphery is equal to or larger than the refractive index of the stored liquid. A display device characterized by the above-mentioned. 56. The display device according to claim 53, wherein the first illumination unit projects light inward from an end surface of the display unit,
And / or a second illuminating means provided on the opposite side of the display unit so as to project light onto the display unit supported by the support unit. Display device. 57. The display device according to claim 23, further comprising: fixing means for fixing the display unit, wherein the fixing means comprises the display unit and the fixing unit. A display device, wherein the display device is provided at a position sandwiching the display body with respect to the objective section.