JPH07209524A - Image display device and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] An image display that provides a bright and clear image, in which the optical image on the image display surface has a wide viewing angle and the image information is not difficult to recognize due to reflection of ambient light. An apparatus and a method for manufacturing the same are provided by an extremely simple method. [Structure] After arranging one end surfaces of a large number of optical fibers 8 on a support plate 3 in a plane, a photosensitive transparent resin 5 containing a light diffusing agent 6 and a surfactant is applied to the surface of the support plate 3, Then, light is projected onto the other end surface of the optical fiber 8 to cure the photosensitive transparent resin 5 around the end surface of the optical fiber 8 in the support plate 3 to form a large number of microlens-shaped light diffusion layers 4, thereby optically. Form the image display surface 3 of the video

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device for transmitting and displaying an optical image from one end face of a large number of optical fibers to an image display face of the other end face, and an improvement in its manufacturing method. The present invention relates to an image display device capable of increasing the size of a surface, having a wide viewing angle, hardly affected by ambient light, and capable of displaying a clear image with high resolution, and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a conventional device for transmitting and displaying an optical image using a large number of optical fibers, there is known an image guide for displaying an image of a full size or an image scope. This device obtains a magnified image on the image display surface by making the distance between the optical fibers on the image display surface, which is the emission surface of the optical fiber, larger than that on the incident surface. The screen size is as large as several tens of inches. The one on the screen. In any of these devices, the image display surface (screen surface) is formed by a cut end surface of a large number of optical fibers, and the light emitted from this end surface has a strong directivity, and an angle of a certain range with the image display surface, That is, although it looks good from a direction close to vertical, it has a drawback that the viewing angle is narrow, that is, it becomes very difficult to see when the angle formed with the vertical of the image display becomes large. Therefore, in the case of a large screen that is supposed to be viewed by a large number of people at once, some means for diffusing the emitted light over a wide angle is required.

As a conventional measure against this problem, a light scattering plate or a light scattering film is attached to an image display surface (hereinafter, referred to as a screen surface when mainly targeting a large screen), and the light is emitted from the optical fiber. It can be classified into two methods: a method of scattering incident light and a method of providing a light scattering structure on the end face of each optical fiber from which light is emitted. However, in the former method, since both the scattering plate and the scattering film have the property of reflecting ambient light, the reflected light mixes with the image information to be originally displayed, which makes the image unclear. There was a problem that the resolution and the contrast of the were lowered.

Regarding the latter method of providing a light-scattering structure only in the light-exiting portion, it is necessary to process each end face of a large number of optical fibers into a shape in which light is easily scattered, especially on a screen surface of several hundred thousand. It was virtually impossible for large screens with the optical fibers of the book.

On the other hand, a method of stacking optical fiber bundles in parallel with each other at a predetermined angle with respect to the screen surface, that is, forming a screen surface with an end surface cut at an angle shallower than perpendicular to the axis of the optical fiber. Have been proposed (for example,
JP-A-61-11782). However, in this method, the magnification ratio to the incident surface and the degree of scattering of the screen surface, that is, the viewing angle are determined at the same time depending on how much the axial direction of the optical fiber bundle is inclined with respect to the screen surface. There was a problem that could not be adjusted independently.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical image on an image display surface with a wide viewing angle and to reflect environmental disturbance light. An object of the present invention is to provide an image display device capable of obtaining a bright and clear image in which image information is not difficult to recognize and a manufacturing method thereof.

[0007]

In order to solve the above-mentioned problems, an image display apparatus according to the present invention has an optical fiber bundle in which a large number of optical fibers are bundled into a bundle, and one end surface and the other end surface of each optical fiber bundle are optically An image display device having an image image display surface and an image incidence surface of an image, wherein (a) the image display surface has a light diffusion layer made of a photosensitive transparent resin formed at an end portion of the optical fiber in a convex lens shape. Many are dispersed as islands of
(B) The height from the end face of the optical fiber of the convex lens to the top of the spherical surface is d / 4 or more and 3d / 2 or less when the diameter of the optical fiber is d (μm), and (c) the light The concentration of the light diffusing agent added to the diffusion layer to the photosensitive transparent resin is 1% by weight or more and 10% by weight or less,
Further, (d) when the height of the convex lens is H (μm) and the added concentration of the light diffusing agent is C (wt%), the value of H × C is 150 or more and 1000 or less. . In this case, the diameter D (μm) of the convex lens is preferably set to the optical fiber diameter d or more and 3d or less.

In order to solve the above-mentioned problems, in the method of manufacturing an image display device according to the present invention, after arranging one end surfaces of a large number of optical fibers in a support plate in a flat shape, the surface of the support plate is exposed to light. A photosensitive transparent resin containing a diffusing agent and a surfactant is applied, and then light is projected onto the other end surface of the optical fiber to cure the photosensitive transparent resin around the end surface of the optical fiber in the support plate to form a convex lens shape. It is characterized in that an image display surface of an optical image is formed by forming a large number of the light diffusion layers. In this case, the coating thickness T (μm) of the photosensitive resin on the support plate is preferably 1.5 times or more the height H of the convex lens to be formed.

[0009]

According to the present invention, when an optical image is projected from the light source onto the image incident surface of the optical fiber bundle, the individual pixels forming the image propagate through the respective optical fibers and exit from the image display surface. Reach the edge. All the pixels emitted from the emission surface of the optical fiber are diffused by the light diffusing agent in the convex lens, and are emitted after passing through the transparent resin.

Therefore, the optical image formed on the image display surface has a wide viewing angle, and a bright and clear image can be obtained in which the image information is not easily recognized by the reflection of the ambient disturbance light.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below by taking a large screen as an example. FIG. 1 is a schematic view of an embodiment of the image display device according to the present invention. In this figure, 1 is a bundle of optical fibers for transmitting image information such as an optical image, 2 is an image incident surface in which end faces of individual optical fibers 8 are arranged in close contact with each other in a plane, and 3 is an image incident surface. , The image display surface, that is, the screen surface, in which the optical fibers are arranged similarly to the incident surface and are arranged at a density lower than that of the incident surface 2. Further, 4 on the display surface 3 is a cured region of a transparent resin formed on the emission end face 7 of each optical fiber 8 by a method described later, that is, a convex lens called a microlens (hereinafter,
It is called a micro lens. ) Is a light diffusion layer. As a method of making an image incident on the image incident surface 2, for example, a transmissive liquid crystal screen is brought into close contact with the image incident surface and light is applied from the back surface, or an image is directly projected on the incident surface by a projector or a video projector.

Next, FIG. 2 is an enlarged plan view of the microlens of FIG. 1, and FIG. 3 is a sectional view of the microlens of FIG. Each optical fiber 8 is sharply cut by aligning the end face with the surface of the support plate 3a constituting the screen surface 3, and the microlens 4 is formed on the end face 7. 5 is a transparent resin that constitutes the microlens 4, 6
Is a light diffusing agent added to the transparent resin. One microlens 4 may be formed on each end face of each optical fiber 7, but one microlens 4 should be formed on each end face of a bundle of any number of 3 to 4 or more optical fibers. You can also By doing so, images of the three primary colors can be separately sent for each bundle of optical fibers, and can be combined on the screen surface 3 for color display, or two optical fibers can be displayed for a weak primary color such as blue. You can also send it with to adjust the overall color balance.

Next, FIG. 4 is a view showing a specific method for forming the light diffusing microlens 4 in the present invention, and the manufacturing method of the present invention will be described based on this drawing.

First, the photosensitive resin 11 containing the light diffusing agent 6 is applied on the support plate 3a to a thickness of several hundreds of micrometers to several thousands of micrometers using a means such as a bar coater. Next, the image entrance surface 2
By irradiating the light source 9 with light having a wavelength suitable for curing the photosensitive resin, the light is transmitted to the image display surface by the individual optical fibers 8 themselves and scattered by the light diffusing agent 6,
A microlens 4 which is a cured region of resin corresponding to the intensity of light in each direction is formed in the peripheral portion of the end surface of the optical fiber.
After irradiation for a certain period of time (details will be described later), the uncured resin is removed, so that only the cured resin remains on the screen surface 3 and microlenses 4 are formed at the end portions of each optical fiber.

By the way, the photosensitive resin used here is
It is preferably as transparent as possible so as not to interfere with the transmission of visible light, and is a polymer compound having a group that undergoes a crosslinking reaction by light, a polymer compound that becomes a photosensitive material by mixing a photocrosslinking agent, or polymerized by light. Although a resin such as a monomer can be used, a photosensitive resin such as acryl, polyamide, or polyester is particularly preferable from the viewpoint of stability of curing and adhesiveness with an optical fiber. Further, in the present invention, the definition of photosensitivity broadly includes a resin curable by light such as visible light, electron beam and X-ray, but an ultraviolet curable resin is preferable from the viewpoint of easy availability and easy handling.

The light source for irradiation is selected according to the characteristics of the resin to be used. For example, in the case of a general UV curable resin, it is preferable to generate UV light having a wavelength of 300 to 400 nm, a metal halide lamp, a high pressure. Mercury lamps and mercury-xenon lamps are suitable.

The light diffusing agent added is 800 at a visible light wavelength.
A transparent granular material having a particle size larger than nm is preferable, and specific examples thereof include glass, quartz, granular materials of inorganic materials such as SiO ₂ LiF and NaF, methacrylic resin, styrene resin,
A shell made of a transparent organic material such as a tetrafluoroethylene resin may be used, but air or a gas such as N ₂ or Ar contained in the micropores formed in the photosensitive resin may be used. Generally, in consideration of stability, dispersibility, price, etc., inorganic materials such as glass and SiO ₂ and Al ₂ O ₃ are preferable.
Moreover, as a concrete method when using them, several μm
It is effective to add 1 to 10% by weight of a granular material having a particle size of several tens of μm. If the amount of the diffusing agent added is too large, the light transmission will be hindered, and the brightness for visually recognizing information, that is, the brightness will be insufficient. On the contrary, when the addition amount is small, the effect of improving the brightness at the viewing angle cannot be obtained, and the brightness retention ratio with respect to the front brightness decreases.

Particularly important is the relationship between the amount of the diffusing agent added and the height of the microlens 4. The preferable lens height is expressed as the height from the end face of the optical fiber to the top of the microlens, and is d / 4 or more and 3d / 2 or less, where d is the diameter of the optical fiber used. When the lens height is d / 4 or less, even if the front luminance is high, the luminance retention rate at the viewing angle becomes too low, and when 3d / 2 or more, the lens height becomes too high and the front luminance becomes low. It will be.

The inventors of the present invention have conducted extensive studies to put this microlens into practical use, and have found that the relationship between the amount of the diffusing agent added and the lens height is very important.

That is, the height of the microlens 4 is set to Hμ.
m and diffusing agent concentration is Cwt%, H × C is 150 to
The fact is that it is preferable to design to a value of 1000, preferably 300-600. This fact means that in the case of a low-height microlens, the diffusing agent concentration is increased to increase the viewing angle luminance retention rate, and in the case of a high lens, the viewing angle luminance can be retained only by the lens shape. This means that the front luminance can be maintained high by decreasing the density.

Further, the diameter Dμm of the microlens 4
Is preferably an optical fiber diameter d or more and 3d or less. The reason is that by setting the lens diameter to be equal to or larger than the diameter d of the optical fiber, the lens spherical surface has an ideal shape having a wide viewing angle in the balance between the lens height and the lens diameter. This is because if the value is 3d or more, the emitted light is excessively diffused and the brightness is insufficient as a whole. Further, in order to form a microlens having the above-mentioned diameter, it is necessary to add the above-mentioned diffusing agent,
Without the appropriate amount of diffusing agent, microlenses having the desired diameter cannot be formed. In order to enhance the light scattering effect of the microlens 4, it is preferable that the transparent particles, which are the diffusing agent, and the photosensitive resin have different refractive indexes. The light diffusing agent may be one that reflects light without absorbing it, such as aluminum fine particles. Further, even if the light diffusing agent is not used, a similar effect can be obtained by providing fine irregularities on the surface of the light diffusing layer. For example, after the uncured transparent resin is removed, the image display surface 3 can be heated and pressed with a roller having fine surface irregularities, or the lens surface can be rubbed with sandpaper or the like to provide fine irregularities. is there.

Next, in order to form the convex lens-shaped microlens 4 of the present invention, a sufficient resin coating thickness T is required as shown in FIG. The coating thickness Tμm of the resin needs to be equal to or larger than the required thickness H of the microlens, but unnecessarily thick coating increases the amount of the uncured resin to be removed, which is not efficient. However, the diameter d of the optical fiber 8 used for the purpose of the present invention is generally 100 to 1
It is in the range of 000 μm, and considering the shape of the microlens required for light diffusion, the resin coating thickness T needs to be 1.5 times or more the required lens height H.
In general, in a photosensitive resin, oxygen in the air acts as a polymerization inhibitor, so it is necessary to allow for an unreacted portion where polymerization is suppressed by oxygen. Without the prospective resin layer in this unreacted area, the desired spherical microlens could not be formed no matter how the light irradiation amount was controlled, resulting in a disc or trapezoidal lens, and the retention rate of the viewing angle luminance decreased. Will cause Coating thickness T of such resin
In the above, the microlens 4 having a height of d / 4 or more and 3d / 2 or less of the optical fiber diameter d, which is the object of the present invention, can be successfully formed.

In order to remove the resin in the uncured portion on the support plate 3a, the surface of the cured portion that maintains the shape of the microlenses is dissolved and removed with a solvent such as alcohol without applying mechanical force. Is desirable. However, depending on the type of solvent, it may affect the screen surface constituent member described below or the cured resin itself, which is not suitable. The best method is to vertically stand the image display surface 3 on which the microlens of FIG. 4 is formed, and naturally remove the uncured resin by free fall. According to this, since the boundary between the cured and uncured resin is not touched, it is possible to form a desired high-quality lens without damaging the surface of the microlens formed according to the light amount distribution. In this case, when the uncured resin is removed with a brush, a spatula, or the like, the lens shape is sometimes deformed, and microlenses having different light directivities are formed, which is not preferable.

Support plate 3 which is the base of screen surface 3
The member forming a is preferably a dark-colored body, particularly a black-colored body. Further, although ceramics, metals, polymeric materials, etc. can be used, polymeric materials such as polyester, polyamide, ABS, vinyl chloride and the like are preferable from the viewpoints of workability, adhesiveness, weight and the like. The area of the ground portion is preferably 70% of the area of the image display surface 3, more preferably 85% or more in order to maintain the contrast of the image.

It is preferable that the microlens 4 does not unnecessarily extend to the ground portion of the screen. The irradiation time that satisfies this condition is, for example, an output of 50 in the case of an ultraviolet curable resin.
With a metal halide lamp of 0 to 1 kw, it takes between a few seconds and a few minutes. However, this alone not only causes insufficient curing of the resin and adhesion to the optical fiber, but when the uncured portion is removed by free fall, the uncured resin is still coated on the surface of the cured resin. , It cannot be put to practical use as it is. Therefore, there is a method of irradiating the formed light diffusion layer with light again after removing the uncured portion. In other words, the same kind of light that was needed to cure the microlens,
The method of irradiating the screen surface from the position of the light source 10 or the method of irradiating the incident surface from the position of the light source 9 may be simultaneously performed. As a result, the formed microlens 4 has an increased adhesive force with the cut end face 7 of the optical fiber and can maintain sufficient strength. In addition, the transparency of the resin is improved by increasing the degree of curing of the resin, and the resin is made uniform as a whole, and a remarkable improvement effect can be obtained in terms of image quality.

In order to obtain the expected effect by the method described above, it is necessary that the photosensitive resin is evenly applied to the screen surface in the state of FIG. The screen surface 3 is often made of a black resin or metal because of the requirement that it has the least reflection as described above and that it is strongly bonded to the cut end surface 7 of the optical fiber. Generally, the photosensitive resin has a large surface tension and poor wettability, and when it is applied as it is, bubbles are generated due to a cissing phenomenon at the interface to form a portion which cannot be coated with the resin. In the production method of the present invention, the surfactant can be applied to the screen surface in advance, or the surfactant can be directly added to the photosensitive resin, whereby the entire screen surface can be evenly applied.

As the surfactant to be used here, various kinds can be adopted as long as they do not impair the properties required for the photosensitive resin of the present application, that is, the transparency and the adhesiveness with the optical fiber. That is, in addition to fatty acid salts, ammonium salts, and ethers generally known as surfactants, silcon oil known to have an effect of lowering surface tension may be used.

According to the manufacturing method of the present invention described above,
Since a large number of light diffusion layers can be simultaneously and easily formed on one support plate, the image display device can be manufactured extremely easily.

The display device of the present invention obtained by such a manufacturing method has the following excellent effects. 1) The viewing angle of an optical image on the image display surface can be arbitrarily set over a wide range. 2) An image display surface with high front brightness, that is, a bright and clear optical image can be obtained. For example, when the front luminance retention ratio (%) is used as an index for determining the size of the viewing angle of the optical image, a conventional image display surface having no light diffusion layer of the present invention has a viewing angle of 20 °. The front luminance retention ratio was at most 10%, but the apparatus of the present invention can obtain a large front luminance retention ratio of about 50% or more. Note that the front luminance retention ratio (%) at a viewing angle of 20 ° is represented by the following definition. Light is projected from the incident surface, and the brightness (Cd /
m ² ) is measured. This is taken as the front luminance (K ₀ ), and then a viewing angle of 20 ° is set to the left or right, and the luminance is measured while keeping the same distance from the display surface. This brightness is 20 ° viewing angle
When the luminance (K ₂₀₎ in pairs front luminance retention rate (%) is represented by _{(K 20 / K 0) ×} 100. 3) Since the ambient light is reflected by forming the light diffusion layer in the shape of a convex lens, a clear image can be obtained.

[0030]

EXAMPLE 1 In the image display device of FIGS. 1 to 3 described above, as the optical fiber 8, the core is made of PMMA (refractive index 1.49) and the clad is made of fluorine resin (refractive index 1.41). Wire diameter 4
A 00 μm plastic optical fiber was used. The image incident surface 2 has a rectangular shape of 146 mm × 205 mm,
The fibers were laminated in a hexagonal close packed state. On the other hand, on the image display surface 3, the arrangement of the optical fibers 8 was made similar to each other, and the fiber pitch was provided with an interval of 2 mm, that is, a magnifying function of 5 times.
Therefore, the size of the image display surface 3 is 760 mm × 10
It became 00 mm. Note that ABS resin was used for the supporting plate 3a on the other part of the screen surface 3.

Further, the image display surface 3 is formed by cutting each optical fiber 8 along with the surface of the supporting plate 3a and polishing the fiber end surface and the supporting plate surface to make them uniform in the same plane.
Approximately 500 acrylic-based UV-curing resin containing 4% by weight of Al ₂ O ₃ powder having a diameter of 5 μm as a light diffusing agent and 1% by weight of silicone oil for reducing the surface tension.
The coating was applied to a thickness of μm, and ultraviolet rays were radiated from the incident surface 2 for 5 minutes to form resin-cured portions on the image display surface 3 to be scattering microlenses. The output of the light source 2 is 1kw.
The high-pressure mercury lamp of No. ² was used to set the ultraviolet intensity on the image display surface 3 to 0.3 w / m ² . After the irradiation, the uncured portion of the ultraviolet curable resin is removed, and again the metal halide lamps (3 units) having an output of 400 w are used as the light source 10, and the screen surface is irradiated with ultraviolet rays continuously for 2.5 hours to expose the final screen surface 3. Formed.

As a result, the microlens 4 on the display surface
Is completely cured and has sufficient adhesive strength with the fiber to withstand impacts such as transportation and cleaning of the display surface. Its height H is 156 μm (0.39 d) and lens diameter D is 6
The thing of 23 micrometers was obtained. The areas of the lens and the ground portion were 8% and 92%, respectively. The optical image on the image display surface 3 has a high luminance retention property at the viewing angle, and the front luminance can maintain a high value of 55% at the viewing angle of 20 °. The front brightness at that time is 293 Cd /
The brightness was perfect at m ² .

Examples 2 to 4 All of Example 1 except that the light diffusion agent addition amount C (Wt%), the transparent resin coating thickness T (μm), the ultraviolet irradiation time and the intensity thereof were appropriately adjusted. Three types of image display surfaces were formed under the same conditions.

As a result, the front luminance is 279 and 2 respectively.
At 83, 265 Cd / m ² and a viewing angle of 20 °, the front luminance retention ratios were 70, 67, and 65%, respectively.

[0035]

[Comparative Examples] Comparative Examples 1 to 8 For comparison, the microlens 4 is not provided on the image display surface 3 at all, the additive amount C, the resin coating thickness T, the lens height H and the lens diameter D are compared. The screen surface 3 was formed in the same manner as in Example 1 except that the values were set to values different from those in Examples 1 to 4. The conditions and effects of Examples 1 to 4 and Comparative Examples 1 to 8 are summarized as follows.
Table 1 below.

[0036]

[Table 1] As is clear from Table 1, in each of Examples 1 to 4, there is a difference in the lens height H and the diffusing agent concentration C, but the front luminance and the front luminance retention rate have high values. On the other hand, in Comparative Examples 1 to 3, all of the values of H × C are 150 to 1000 inclusive, but in Comparative Example 1, the lens 4 is not provided. Sa H is 90
Since it is as low as μm, the diffusing agent concentration C is 0.5 in Comparative Example 3.
Since the wt% is too low, Comparative Example 1 has a front luminance of 560μ.
m is extremely high, but the viewing angle is 6%, which is extremely low.
Has a low viewing angle of 31%, and Comparative Example 3 has a front luminance of 1
It was inferior to 55 Cd / m ² . In Comparative Example 4, the lens height H and the diffusing agent concentration C are satisfied, but the value H × C is low. Therefore, although the front luminance is sufficient, the luminance retention rate at the viewing angle is low at 37%. In Comparative Example 5, the lens height H, the diffusing agent concentration C, H × C, and the lens diameter D are satisfied, but the coating thickness T of the transparent resin is less than 1.5H, so the lens shape is spherical. Since it does not form a convex lens, the viewing angle characteristics are slightly inferior. Further, in Comparative Example 6, since the lens height H is too high, in Comparative Example 7, the density C is too high, and in Comparative Example 8, the lens diameter D is too high, so that the front luminance is inferior to that in each Example. Was there. Therefore, although the front luminance and the viewing angle are different from each other when compared with the comparative example, it is found that the high values of the two are well balanced in Examples 1 to 4.

[0037]

As described above, in the image display device according to the first and second aspects, the optical image on the image display surface has a wide viewing angle, and the image information is not easily recognized due to the reflection of the ambient disturbance light. , A bright and clear image can be obtained.

That is, whether it is indoors or outdoors, a small image that can be displayed on a liquid crystal screen or the like can be enlarged to display a high-contrast, clear image, and can be viewed by a large number of people at the same time. It is very useful as a large display device. Further, since the light diffusion layers of many spherical microlenses are distributed on the island on the image display surface, an uneven surface is inevitably formed on the display surface.
It makes the ambient light extremely difficult to reflect, and when it recognizes the information light expressed by the light diffusion layer, it mixes with the ambient light,
There is no drawback that the information light is difficult to recognize, and the information light can be recognized very easily by visual observation.

According to the method of manufacturing the image display device of claims 3 and 4, the photosensitivity is obtained by adding a light diffusing agent and a surfactant to the surface of the supporting plate on which one end surfaces of a large number of optical fibers are arranged in a plane. A transparent resin is applied, and then light is projected from the other end surface of the optical fiber to cure the photosensitive transparent resin on the support plate.Thus, by such an operation, a large number of light diffusion layers are simultaneously formed on one support plate, and It can be easily formed, and the image display device can be manufactured very easily.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of an image display device according to the present invention.

FIG. 2 is an enlarged plan view of the microlens of FIG.

FIG. 3 is a cross-sectional view of the microlens of FIG. 2 taken along arrow XX.

FIG. 4 is an explanatory view of the method for manufacturing the image display device according to the present invention.

[Explanation of symbols]

 1: Optical fiber bundle 2: Image incident surface 3: Image display surface (screen surface) 3a: Support plate 4: Convex lens (light diffusion layer) 5: Cured photosensitive transparent resin 6: Light diffusion agent 7: Cutting of optical fiber End face (image emission surface) 8: Optical fiber 9, 10: Light source 11: Coated photosensitive resin 12: Support frame d: Diameter of optical fiber D: Outer diameter of convex lens

Claims (4)

[Claims] 1. An image display device in which one end surface and the other end surface of the optical fiber bundle, in which a large number of optical fibers are bundled, are an image display surface and an image incident surface of an optical image, respectively. ) On the image display surface, a large number of light diffusion layers made of a photosensitive transparent resin formed at the end portion of the optical fiber are dispersed as convex lens-shaped islands, and (b) from the end surface of the optical fiber of the convex lens. The height to the top of the spherical surface is d / 4 or more and 3d / 2 or less, where d (μm) is the diameter of the optical fiber, and (c) the light diffusing agent added to the light diffusing layer. The addition concentration to the photosensitive transparent resin is 1% by weight or more and 10% by weight or less, and (d) the height of the convex lens is H (μm), and the addition concentration of the light diffusing agent is C (wt%). And the value of H × C is 15
An image display device, which is 0 or more and 1000 or less. 2. The image display device according to claim 1, wherein a diameter D (μm) of the convex lens is not less than the optical fiber diameter d and not more than 3d. 3. After arranging one end surfaces of a large number of optical fibers on a support plate in a plane, a photosensitive transparent resin containing a light diffusing agent and a surfactant is applied to the surface of the support plate, and then the above-mentioned. By projecting light on the other end surface of the optical fiber to cure the photosensitive transparent resin around the end surface of the optical fiber in the support plate to form a large number of convex lens-shaped light diffusing layers, an image display surface of an optical image is formed. A method for manufacturing an image display device, which is characterized by being formed. 4. The coating thickness T (μm) of the photosensitive resin on the support plate is 1.5 times or more the height H of the convex lens to be formed. A method for manufacturing the image display device described.