JP2012173473A - Diffusion member and lighting system - Google Patents

Abstract

To provide a diffusing member and an illuminating device capable of suppressing glare derived from a point light source with high luminance and suppressing a decrease in total luminous flux.
A diffusing member (13) according to the present invention is a diffusing member (13) made of a light transmissive material and having a pair of main surfaces, and is provided adjacent to each other in the pair of main surfaces. It has at least one first region A1 and a plurality of second regions A2, and the first region A1 and / or the second region A2 has a first surface on at least one main surface of the pair of main surfaces. Including a concavo-convex structure for diffusing the light emitted from the region A1 and the second region A2, the light incident on the first region A1 and the second region A2 is mutually transmitted from the first region A1 and the second region A2. It emits light at different diffusion angles.
[Selection] Figure 8

Description

  The present invention relates to a diffusing member, for example, a diffusing member that diffuses light emitted from a point light source such as an LED, and an illumination device using the diffusing member.

  In recent years, the light source of an illuminating device is being largely replaced by an LED light source effective for power saving from a conventional incandescent bulb or fluorescent lamp. However, since the LED light source has a small area of the light emitting portion and high luminance, there is a problem that unpleasant glare (glare) can be felt when looking directly. In order to suppress this glare, the LED light source is arranged at the bottom of the concave reflector, the light emission angle is limited by a baffle or louver, or a diffusing member such as a lens or milky white diffusion cover is arranged on the light emitting surface. Such a method is used.

  When a diffusing member is disposed on the light exit surface of the lighting device, the amount of light (total luminous flux) is generally reduced with the diffusion of light. In order to solve such a decrease in the amount of light accompanying the diffusion of light, there has been proposed an illuminating device using a diffusion cover whose transmittance is partially changed (see, for example, Patent Document 1).

  The illumination device described in Patent Literature 1 includes a plurality of LEDs mounted on a substrate and a light-transmitting cover provided on the light exit surface side of the plurality of LEDs. In the illuminating device described in Patent Document 1, a diffusion means in which a diffusing agent such as titanium oxide is applied is provided in a partial region of the light-transmitting cover, and the light emitted from the LED by the diffusion means is provided. By blocking a part, the occurrence of glare is suppressed.

JP 2010-123344 A

  However, in the illuminating device described in Patent Document 1, since the transmittance of light is controlled by shielding a part of the transmitted light by the diffusing means, the transmittance is higher than that of the milky white plate, but the occurrence of glare is sufficiently suppressed. In order to achieve this, a certain decrease in transmittance is unavoidable, and there is a problem that the total luminous flux decreases.

  Moreover, in the illuminating device of patent document 1, generation | occurrence | production of a glare is suppressed by providing a spreading | diffusion means in the area | region corresponding to the LED light source in a translucent cover. However, since the LED light source has a small area of the light emitting part, the light emitting part of the LED light source and the light transmissive cover are caused by play of the attaching part when the light transmissive cover is attached to the lighting device or deformation of the lighting device itself. When the position of the diffusing unit is shifted, there is a problem that the occurrence of glare cannot be suppressed. In addition, there is a problem that the light-transmitting cover whose optical characteristics are customized in accordance with the position corresponding to the LED light source cannot be diverted to other lighting devices having different LED light source positions.

  This invention is made | formed in view of this point, and it aims at providing the diffusion member and illuminating device which can suppress the glare originating in a high-luminance point light source and can suppress the fall of a total light beam.

  As means for solving the above problems, a diffusing member and a lighting device having the following configurations are proposed.

  The diffusing member of the present invention is a diffusing member made of a light-transmitting material and having a pair of main surfaces, and at least one first region and a plurality of adjacent regions provided adjacent to each other in the pair of main surfaces. The first region and / or the second region has light emitted from the first and second regions on at least one main surface of the pair of main surfaces. In which the diffusion angles in the first and second regions are different from each other.

  According to this configuration, the light emitted from the first and second regions is diffused in different directions and emitted by the uneven structure provided in the first region and / or the second region. The luminance of the area near the light source in the main surface can be reduced. As a result, it is possible to suppress the occurrence of glare even in an illumination device using a point light source with high luminance. Further, since glare is suppressed by the difference in diffusion angle between the first and second regions, it is possible to suppress a decrease in total luminous flux.

  In the diffusing member of the present invention, the first and second regions are provided on at least one main surface of the pair of main surfaces, respectively, and unevenness for diffusing light emitted from the first and second regions. It preferably includes a structure. With this configuration, since the diffusion patterns of the first and second regions are controlled by the uneven structures provided in the first and second regions, the occurrence of glare can be effectively suppressed.

  In the diffusing member of the present invention, it is preferable that the pair of main surfaces of either the first region or the second region is flat. With this configuration, the diffusion of light in either the first or second region is reduced, so that the decrease in the total luminous flux can be further suppressed.

  In the diffusing member of the present invention, it is preferable that the plurality of second regions have the same shape.

  In the diffusing member of the present invention, it is preferable that the plurality of second regions are regularly arranged.

  In the diffusing member of the present invention, it is preferable that the diffusion member has a plurality of the first regions, and that all of the first and second regions have the same shape.

  In the diffusing member of the present invention, the diffusion angle of light emitted when light enters perpendicularly from the concavo-convex structure forming surface in the first region, and the concavo-convex structure forming surface in the second region It is preferable that both of the diffusion angles of light emitted when light enters vertically from within the range of 0.1 to 100 degrees.

  The illumination device of the present invention includes at least one point light source and the diffusion member provided in the light emission direction of light emitted from the point light source. According to this configuration, the light emitted from the point light source is diffused and emitted by the diffusing members having the first and second regions showing different diffusion patterns, so that the occurrence of glare can be suppressed. Moreover, since the shielding and absorption of light in the first and second regions can be reduced, it is possible to suppress a decrease in the total luminous flux.

  In the illumination device of the present invention, when the light exit surface of the diffusing member is viewed from the front, at least a part of the first region and the second region are within the projection range of the light emitting units of at least half of the point light sources. It is preferable that at least a part of the region is included.

  In the illuminating device of the present invention, at least the areas of all of the plurality of first regions and the plurality of second regions that overlap with the projection region of the light emitting unit of the point light source are the points. It is preferable that the area is smaller than the area of the projection region of the light emitting part of the light source.

  In the illuminating device of the present invention, it is preferable that the area of all the regions of the plurality of first regions and the plurality of second regions is smaller than the area of the light emitting projection unit of the point light source.

  ADVANTAGE OF THE INVENTION According to this invention, the diffusion member and illuminating device which can suppress the glare originating in a point light source with a high brightness | luminance and can suppress the fall of a total light beam can be provided.

It is a cross-sectional schematic diagram of the illuminating device which concerns on this Embodiment. It is explanatory drawing which shows the measurement direction of the diffusion angle of the diffusion member which concerns on this Embodiment. It is explanatory drawing which shows the definition of the diffusion angle in the diffusion member which concerns on this Embodiment. FIG. 4A is an explanatory diagram of an isotropic diffusion pattern according to the present embodiment, and FIG. 4B is an explanatory diagram of an anisotropic diffusion pattern according to the present embodiment. It is a plane schematic diagram of the diffusion member which concerns on this Embodiment. It is a plane schematic diagram of the diffusion member which concerns on this Embodiment. It is a plane schematic diagram of the diffusion member which concerns on this Embodiment. It is a schematic diagram which shows an example of the positional relationship of the 1st-3rd area | region of a diffusing member, and a point light source in the illuminating device which concerns on this Embodiment. It is a schematic diagram which shows the other example of the positional relationship of the 1st-3rd area | region of a diffusion member and point light source in the illuminating device which concerns on this Embodiment. It is a schematic diagram of the LED light source used in the Example. It is a cross-sectional schematic diagram which shows arrangement | positioning with the point light source and diffusion member of the illuminating device of an Example. It is a figure which shows the light distribution of the illuminating device which concerns on an Example. It is a figure which shows the light distribution of the illuminating device which concerns on a comparative example.

  The diffusing member according to the embodiment of the present invention is a diffusing member made of a light transmissive material and having a pair of main surfaces. This diffusion member has at least one first region and a plurality of second regions provided adjacent to each other in a pair of main surfaces, and the first region and / or the second region The region includes a concavo-convex structure that diffuses light emitted from the first and second regions on at least one main surface of the pair of main surfaces, and the diffusion angles in the first and second regions are different from each other.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following, an embodiment in which the diffusing member according to the present invention is applied to a lighting device will be described. However, the diffusing member according to the present invention is not limited to this as long as it diffuses incident light and emits light. It can be applied to various devices.

1A to 1C are schematic cross-sectional views of an illumination device according to an embodiment of the present invention.
As shown in FIGS. 1A to 1C, the lighting device according to the present embodiment is arranged so as to be separated from each other on the support body 11 having side walls at both ends and one surface side (light-emitting surface side) of the support body 11. A plurality of point light sources 12 provided, and a diffusing member 13 provided on the light exit surface side of the plurality of point light sources 12 are provided.

  The support 11 is provided with a reflection member on the arrangement surface (light exit surface) of the point light source 12, and is configured to reflect the light emitted from the point light source 12 toward the diffusion member 13. The diffusing member 13 has a generally flat plate shape and is made of a light transmissive material composed of a thermoplastic resin, a thermosetting resin, a photocurable resin, glass, or a composite material thereof.

  The diffusing member 13 has at least one first region A1 and a plurality of second regions A2 provided adjacent to each other in a pair of main surfaces (see FIGS. 5 to 7). An uneven structure for diffusing light emitted from the first region A1 and / or the second region A2 is provided in at least one main surface of the first region A1 and / or the second region A2 of the diffusion member 13. Provided, and the first region A1 and the second region A2 are configured to exhibit different diffusion patterns. In the diffusing member 13, incident light incident from the main surface on the light source side (hereinafter referred to as "incident surface") passes through the first region A1 and the second region A2 that show different diffusion patterns, respectively. Glare can be reduced by emitting light at different diffusion angles from the main surface (hereinafter referred to as “light-emitting surface”) opposite to the point light source 12. The light exit surface of the diffusing member 13 may be subjected to predetermined antireflection treatment or the like within a range that does not impair the desired light distribution characteristics in order to suppress glare.

  In the present embodiment, it is preferable that the first region A1 and the second region A2 of the diffusing member 13 include an uneven structure provided on the incident surface and / or the light exit surface of the diffusing member 13, respectively. Thereby, it becomes possible to control the diffusion angles of the first region A1 and the second region A2 respectively by the concavo-convex structure, and it becomes easy to suppress the occurrence of glare. The uneven structure of the diffusing member 13 may be provided on the light exit surface side (FIG. 1A), may be provided on the incident surface side (FIG. 1B), and is provided on each of the entrance surface and the light exit surface. (FIG. 1C). In the following description, the main surface of the diffusing member 13 on the point light source 12 side will be referred to as an incident surface, and the main surface opposite to the incident surface will be described as a light exit surface.

  The first region A1 and the second region A2 of the diffusing member 13 are preferably provided over the entire incident surface and / or light exit surface of the diffusing member 13. By providing the first region A1 and the second region A2 over the entire surface, the occurrence of glare can be effectively suppressed when the diffusing member 13 is used in a lighting device. Further, since the first region A1 and the second region A2 are provided over the entire incident surface and / or light exit surface of the diffusing member 13, glare other than the direction perpendicular to the main surface of the diffusing member 13 is also suppressed. It is also possible to prevent glare depending on the angle at which the illumination member is viewed (oblique glare).

  In the illumination device according to the present embodiment, the distribution of the emitted light intensity (diffusion angle, isotropic / anisotropy) is controlled by the shape, width, and height of the concavo-convex structure of the diffusing member 13. For this reason, it is possible to control the diffusion pattern in the first region A1 and the second region A2 by providing an arbitrary uneven structure on at least one main surface of the diffusion member 13. In the present invention, the diffusion angle is defined as the diffusion angle of the outgoing light and the state of the outgoing light intensity distribution defined by the isotropic / anisotropy of the outgoing direction of the outgoing light.

  Here, the isotropic / anisotropy of the diffusion angle and the outgoing direction of the outgoing light will be described. In the present invention, the diffusion angle is an angle measured by measuring the intensity of light emitted when light is incident in a direction perpendicular to the main surface on which the concavo-convex structure of the diffusion member 13 is formed, as shown in FIG. In the curve plotted with the intensity (FIG. 3), the angle (Full Width Half Maximum, hereinafter also referred to as “FWHM”) that is twice the angle that attenuates to half the peak intensity (half-value angle) is shown.

  For the diffusion angle, for example, using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., GC 5000L), the main surface on which the concavo-convex structure of the diffusing member 13 is formed (hereinafter referred to as the concavo-convex surface) is used as the light incident surface. It is obtained by measuring the angular distribution of transmitted light intensity with respect to incident light in the normal direction of the main surface (see the dotted line in FIG. 2) on which the concavo-convex structure is formed. Here, the normal direction of the diffusing member 13 indicates a direction perpendicular to the concavo-convex surface of the diffusing member 13, as shown in FIG. In FIG. 2, light that is incident from the normal direction of the concavo-convex surface among the light in various directions that transmits the diffusing member 13 is transmitted in the vertical direction (reference angle 0 degree) from the concavo-convex surface of the diffusing member 13 Has the highest transmitted light intensity. A double angle of the angle (angle from the reference angle) when the transmitted light intensity is half of the highest transmitted light intensity (peak intensity) is the diffusion angle (FWHM) (see FIG. 3).

  4A and 4B are explanatory diagrams of the isotropic / anisotropy of the emitted light. In the present invention, as shown in FIG. 4A, the isotropic diffusion pattern is used when the outgoing light transmitted through the diffusing member 13 shows the same diffusion angle in any direction (in FIG. Direction and the diffusion angle in the Y direction are the same). On the other hand, as shown in FIG. 4B, when the outgoing light transmitted through the diffusing member 13 has different diffusion angles depending on directions, anisotropic diffusion is performed (in FIG. 4B, the diffusion angle in the X direction is Y Great with respect to direction). In the present embodiment, as the diffusing member 13, a member showing either an isotropic diffusion pattern or an anisotropic diffusion pattern can be used.

  Further, in the diffusing member 13 according to the present embodiment, when the diffusion pattern is an isotropic diffusion pattern, the difference in diffusion angle with respect to the diffusion angle a at the point A and the diffusion angle b at the point B ( When ab) is within a range of ± 10% of the average value of diffusion angles {(a + b) / 2}, point A and point B are assumed to belong to the same region. Further, when the above conditions are not satisfied, the points A and B belong to regions having different diffusion patterns.

  In the diffusion member according to the present embodiment, when the diffusion pattern is an anisotropic diffusion pattern, the diffusion angle amax in the direction in which the diffusion angle at the point A is the maximum and the direction in which the diffusion angle is the minimum The difference in maximum diffusion angle (amax−bmax) is the maximum diffusion angle with respect to the diffusion angle amin, the diffusion angle bmax in the direction in which the diffusion angle at the point B is maximum, and the diffusion angle bmin in the direction in which the diffusion angle is minimum. Is within the range of ± 10% of the average value {(amax + bmax) / 2}, and the difference of the minimum diffusion angle (amin−bmin) is within the range of ± 10% of the average value {(amin + bmin) / 2} of the minimum diffusion angle When the angle formed by the direction in which the diffusion angles at points A and B are the maximum is within 5 degrees, point A and point B belong to the same region where the diffusion patterns belong to each other. It shall be. Further, when at least one of the above conditions is not satisfied, the point A and the point B belong to regions having different diffusion patterns. In the following description, for the convenience of explanation, the diffusion pattern is assumed to be an isotropic diffusion pattern unless otherwise specified.

  In the present embodiment, the diffusion angles of the first region A1 and the second region A2 of the diffusing member 13 can be obtained by the following method. First, for example, the diffusion angle is measured over the entire surface of the diffusion member 13 at a pitch of 2 mm in the vertical direction (X direction) and 2 mm in the horizontal direction (Y direction) (measured partially at a finer pitch if necessary). You may do it.) Second, each measurement point is divided into a first area A1 and a second area A2 in accordance with the criteria for determining whether the diffusion pattern is the same area or a different area.

  For example, when the diffusion angles of the measurement points measured in the vertical direction (X direction) are 50, 47, 50, 53, 50, 10, 11, 9, 10, 49, 51 degrees in order, the first region The diffusion angle indicated by A1 is 50 ± 5 degrees, and the diffusion angle indicated by the second region A2 is 10 ± 1 degrees. In this case, there is a boundary line between the first region A1 and the second region A2 between the measurement point with the diffusion angle of 50 and the measurement point of 10, and the measurement point with the diffusion angle of 10 and 49 There is a boundary line between the second region A2 and the first region A1 in the middle. Thus, the main surface of the diffusing member 13 can be divided into the first region A1 and the second region A2 by drawing a boundary line over the entire surface of the diffusing member 13.

  The diffusion angle of a region means an average value of the maximum value and the minimum value of the measurement values of the diffusion angle in the region. As the diffusion angle indicated by the diffusion pattern of the first region A1 and the second region A2, the difference in diffusion angle between the first region A1 and the second region A2 is preferably 10 degrees or more. If the difference in diffusion angle between the first region A1 and the second region A2 is 10 degrees or more, the difference between the diffusion pattern indicated by the first region A1 and the diffusion pattern indicated by the second region A2 becomes large. Therefore, the change in the optical characteristics of the transmitted light that passes through the diffusing member becomes large, and glare can be suppressed.

  In the diffusing member 13 according to the present embodiment, at least one first region A1 and a plurality of second regions A2 showing different diffusion patterns are provided adjacent to each other in the main surface of the diffusing member 13. It is done. “The first region A1 and the second region A2 are arranged adjacent to each other in the main surface” means that a plurality of values in the main surface of the diffusing member 13 are measured according to the measurement value of the diffusion angle as described above. When dividing into regions, it means that at least part of the boundary line of the first region A1 is a boundary line with the second region A2, and the entire boundary line of the first region A1 is not necessarily It does not have to be a boundary line with the second region A2. The first region A1 is disposed adjacent to the second region A2, and is disposed adjacent to the third region A3 that does not belong to the first region A1 or the second region A2. May be. Further, the first area A1 is arranged adjacent to the second area A2 and the third area A3, and the first area A1 and the second area A2 are both in the third area A3. May be arranged adjacent to the fourth region A4 that does not belong (see FIG. 7).

  For the diffusion member 13 whose diffusion pattern is isotropic diffusion, the diffusion pattern is expressed as 60 degrees or 60 degrees x 60 degrees based on the result of measuring the diffusion angle by the above-described measurement method. With respect to the diffusion member 13 for anisotropic diffusion, the diffusion angle in two directions, that is, the direction in which the diffusion angle is maximum and the direction orthogonal to the direction in which the diffusion angle is maximum is measured, for example, 60 degrees × 10 degrees Or 90 degrees × 30 degrees or the like (usually, the maximum diffusion angle is described before and the minimum diffusion angle is described later).

  Next, referring to FIGS. 5A to 5F and FIGS. 6A to 6C, an example of the arrangement of the first region A1 and the second region A2 in the diffusing member 13 of the lighting device according to the present embodiment will be described in detail. explain. FIGS. 5A to 5F and FIGS. 6A to 6C are schematic plan views of the diffusing member 13 in the lighting apparatus according to the present embodiment, and show an arrangement example of the first region A1 and the second region A2. . In FIGS. 5A to 5F and FIGS. 6A to 6C, the first area A1 is also referred to as area A1, and the second area A2 is also referred to as area A2.

  In the example shown in FIGS. 5A to 5F, the first region A1 exists continuously in the plane of the diffusing member 13, and a plurality of second regions A2 are surrounded by the first region A1. Exists. Thus, when the second region A2 is divided by the closed line in the main surface of the diffusing member 13, the first region A1 is singular, and a plurality of the first regions A1 are surrounded by the first region A1. A second area A2 exists.

  In the example shown in FIGS. 6A to 6C, an example is shown in which the second region A <b> 2 is not separated by a closed line in the main surface of the diffusing member 13. In this case, a configuration having a plurality of first regions A1 and a plurality of second regions A2 may be used (FIG. 6A), and a configuration having a single first region A1 and a plurality of second regions A2. (FIGS. 6B and 6C). The shape of the diffusion member 13 may be a substantially rectangular shape (FIGS. 5A to 5C, 5E, 5F, 6A, and 6B) in a plan view, or a circular shape (FIGS. 5D and 5B). 6C), and can be appropriately selected depending on the lighting device to which the diffusing member 13 is applied.

  In the diffusing member 13 according to the present embodiment, the shapes of the plurality of second regions A2 provided in the main surface of the diffusing member 13 are preferably substantially the same shape, and the second regions A2 are regularly formed. More preferably, they are arranged. Thus, by arranging the second regions A2 showing substantially the same diffusion pattern in substantially the same shape, regularity occurs in the distribution of the diffusion angle in the main surface of the diffusion member 13, so that the diffusion angle of the emitted light is It is possible to effectively reduce the uniform glare. Furthermore, by arranging the second regions A2 regularly, the diffusion angles of the emitted light are more uniform, so that the glare can be reduced more effectively.

  5A, FIG. 5C to FIG. 5F, and FIG. 6A to FIG. 6C have described examples in which the diffusion patterns of the first region A1 and the second region A2 are both isotropic diffusion patterns. As described above, the diffusion patterns of the first region A1 and the second region A2 may both be anisotropic diffusion patterns. Further, either one of the first region A1 and the second region A2 may be an isotropic diffusion pattern, and the other diffusion pattern may be an anisotropic diffusion pattern.

  When both of the first region A1 and the second region A2 are anisotropic diffusion patterns, they are classified into the following cases. That is, the diffusion angle of the anisotropic diffusion pattern in the first region A1 is a degree × b degrees, and the diffusion angle of the anisotropic diffusion pattern in the second region A2 is c degrees × d degrees (a ≠ c, In the case of b ≠ d, a> b, c> d), and as shown in FIG. 5B, the anisotropic diffusion patterns of the first region A1 and the second region A2 are both a degree × b degree. There are cases where the direction of maximum anisotropy is different. In the first region A1 and the second region A2 in FIG. 5B, the direction of anisotropy is schematically shown in the direction of the oblique lines. The diffusion angle of the anisotropic diffusion pattern is a degree × b degree in both the first region A1 and the second region A2, but the directions indicating anisotropic diffusion are different from each other by 90 degrees.

  In the present embodiment, in the diffusing member 13, the arrangement of the first region A1 and the second region A2 may be random, and the shapes of the first region A1 and the second region A2 are different from each other. May be. From the viewpoint of ease of manufacturing, it is preferable that at least the second region A2 is regularly arranged. The second region A2 is regularly arranged means that the arrangement of the points serving as the center of gravity of the second region A2 in plan view of the main surface of the diffusing member 13 has a structure that is periodically repeated. Means that Manufacturing is easy because a plurality of second regions A2 are arranged on a straight line at equal intervals (for example, FIGS. 5A, 5B, 5C, 5E, and 5F) or on the same circumference. The second region is arranged at equal intervals (for example, FIG. 5D).

  In the present embodiment, the shape of the second region A2 in the main surface of the diffusing member 13 is a circle, a polygon, or a shape composed of a curve and / or a straight line. The shape and area of the second region A2 can be appropriately selected according to the application and purpose. However, from the simplicity of manufacturing, the shape itself such as a perfect circle, an ellipse, a polygon, and a star is symmetrical with respect to the figure itself. Or a shape having point symmetry.

  The first region A1 and the second region A2 (third region A3 and fourth region A4) are regions having substantially the same shape in plan view, and can fill the in-plane. It is preferable for the production of the pattern prototype to be a simple shape. For example, as shown in FIG. 7A to FIG. 7F, the region in which the in-plane can be filled with the region having the same shape is a square (rectangular) shape in the first to fourth regions A1 to A4. , Regular triangles, right-angled isosceles triangles, regular hexagons, and unit figures connected by points and sides.

  As shown in FIGS. 7A to 7F, when the main surface of the diffusing member 13 is filled with the first to fourth regions A1 to A4 having the same shape, there are necessarily two types of diffusion patterns. In particular, in the first to fourth regions A1 to A4, two types of regions are repeatedly arranged (FIGS. 7C and 7F). When there are three or more types of areas, the arrangement of the first area A1 to the third area A3 may be regular as shown in FIGS. 7A and 7D, as shown in FIGS. 7B and 7E. In addition, the arrangement of the first region A1 to the fourth region A4 may be irregular.

  In the diffusing member 13 according to the present embodiment, the concavo-convex structure that forms a diffusion pattern of emitted light has a function of controlling a diffusion angle and anisotropy called a diffusion pattern. The concavo-convex structure is formed by forming a minute lens pattern or concavo-convex by machining, laser cutting, interference exposure method, or the like. In such a processing method, since the process is very complicated and the original mold is expensive, it is difficult to obtain a fine uneven pattern having a large area. In the present embodiment, if a small uneven pattern with a small area can be formed, the light emission characteristics of the entire diffusing member can be freely controlled by combining several patterns. Further, if the shapes of the first region A1 and the second region A2 are the same, a simulation for obtaining a required light emission characteristic from a certain type of diffusion pattern becomes simple, and there is little difference from the actually measured value. Become.

  In the present embodiment, the diffusing member 13 has a diffusion angle of light emitted when light is incident vertically from a surface where the concavo-convex structure is formed in the first region A1, and a concavo-convex structure in the second region A2. From the viewpoint of manufacturing, it is preferable that the diffusion angles of the light emitted when light is vertically incident from the formed surface are in the range of 0.1 to 100 degrees. When the diffusion pattern of a certain region is anisotropic diffusion, it is preferable that both the minimum diffusion angle and the maximum diffusion angle are within this range.

  Specifically, a diffusion member composed of two regions, a first region A1 having a diffusion angle of 0 to 20 degrees and a second region A2 having a diffusion angle of 30 to 50 degrees, and a diffusion angle of 0 to 5 degrees A diffusion member consisting of three regions, a first region A1, a second region A2 having a diffusion angle of 6 to 19 degrees, and a third region A3 having a diffusion angle of 20 to 40 degrees. A diffusion member composed of three regions: a first region A1 of ˜9 degrees, a second region A2 of a diffusion angle of 10 to 29 degrees, and a third region A3 of a diffusion angle of 30 to 50 degrees; It consists of three regions: a first region A1 having a diffusion angle of 0 to 19 degrees, a second region A2 having a diffusion angle of 20 to 39 degrees, and a third region A3 having a diffusion angle of 40 to 60 degrees. A diffusion member can be preferably exemplified.

  Moreover, in the illuminating device according to the present embodiment, either one of the first area A1 and the second area A2 in the main surface of the diffusion member 13 is flat on both main surfaces of the diffusion member 13. It is preferable. Here, flat means that the diffusion angle measured in the first region A1 or the second region A2 is less than 0.1 degree. That is, at least two types of regions including one or a plurality of first regions A1 and a plurality of second regions A2 are provided in the main surface of the diffusing member 13, and the first region A1 and the second region A2 are provided. Are provided adjacent to each other in the main surface. One of the first region A1 and the second region A2 is flat on both main surfaces, and a diffusion pattern is shown on at least one other main surface of the first region A1 and the second region A2. An uneven structure is formed. Thereby, in one of the first region A1 and the second region A2, the incident light is transmitted without diffusing, and the light incident on the other region is diffused by the concavo-convex structure and is emitted. It is possible to further suppress the decrease in the total luminous flux while suppressing the occurrence of.

  When the diffusion member 13 is provided with two or more types of regions showing different diffusion patterns in which the emitted light transmitted through the diffusion member 13 is different, it is preferable that the difference between the diffusion angles of the diffusion patterns in each region is 10 degrees or more. If the difference in diffusion angle in each region is greater than 10 degrees, the change in optical characteristics due to the combination of a plurality of diffusion patterns increases.

  In addition, as in the example shown in FIG. 5B, the ones having anisotropic diffusion characteristics with the same diffusion angle of a degree × b degrees are arranged at different angles for each of the first region A1 and the second region A2. In this case, the angle difference in the direction of the angle indicating the maximum angle is preferably 15 degrees or more. When the angle difference is 15 degrees or more, a change in optical characteristics caused by changing the direction of anisotropy becomes large.

  In the diffusing member 13 according to this embodiment, the concavo-convex structure is formed on at least one of a light incident surface on which light from the point light source 12 enters and a light output surface on which light from the light source emits light. What is necessary is just to be formed in both surfaces of the light-incidence surface and the light emission surface.

  In particular, it is arranged so that the surface on which the concavo-convex structure is formed becomes the light exit surface, and the light that is emitted from the light source in an oblique direction is raised in the front direction by retroreflection, and the transmitted image of the light source is blurred. It is preferable from the viewpoint of obtaining the effect of suppressing glare.

  The concavo-convex structure of the diffusing member 13 is not particularly limited as long as it has a structure in which a large number of protrusions are provided on the surface, and concavo-convex structures of various shapes can be used. The shape of the protrusions may be, for example, a substantially conical shape, a substantially spherical shape, a substantially ellipsoidal shape, a substantially lenticular lens shape, or a substantially parabolic shape, and the protrusions may be regularly arranged, They may be arranged irregularly. Moreover, between each projection part which comprises an uneven structure may be connected with the continuous curved surface. Furthermore, a pseudo-random structure in which irregular irregularities are connected by a continuous curved surface can be preferably used.

  The shape of the concavo-convex structure is controlled by adjusting the spraying amount by the sand blast method, adjusting the coating amount by applying resin beads to the main surface of the diffusion member 13 to form the concavo-convex structure, or adjusting the bead diameter. can do. By controlling the shape of the concavo-convex structure by these methods, a desired diffusion angle can be obtained. Among these methods, it is particularly preferable to control the shape of the concavo-convex structure using a speckle pattern by interference exposure because the setting of the diffusion angle becomes easy. Further, the three-dimensional structure formed using the speckle pattern by interference exposure can be a fine concavo-convex structure having a concavo-convex pitch of 20 μm or less, which has been difficult by machining.

  Also, according to the method of forming a concavo-convex structure using a speckle pattern by interference exposure, both a shape showing isotropic diffusion like a microlens and a shape showing anisotropic diffusion like a lenticular lens are used. Since it can be formed easily, it is a suitable method for forming the concavo-convex structure of the diffusion member.

  The shape of the concavo-convex structure provided on the light entrance surface and / or the light exit surface of the diffusing member 13 can be arbitrarily designed according to the width and shape of the target irradiation range. The shape can be controlled.

  The pitch and height of the concavo-convex structure of the diffusing member 13 is preferably less than the resolution of the human eye, that is, 20 μm or less. Further, the wavelength of visible light is preferably 0.8 μm or more.

  In addition, the uneven structure is preferably an irregular uneven structure formed by a continuous curved surface from the viewpoint of suppressing the glare on the surface and the viewing angle dependency of luminance on the light emitting surface of the lighting device. The irregular fine concavo-convex structure formed from a continuous curved surface can be manufactured as follows.

  First, the original pattern of unevenness that becomes a uniform diffusion pattern area in which a speckle pattern is formed by previously irradiating a photosensitive material or photoresist with laser light through a lens, a diffuser plate, an aperture, a mask, etc. by interference exposure. Is made. A desired concavo-convex structure, that is, a light diffusion pattern, can be obtained by adjusting the size, shape and direction of the speckle pattern by changing the distance and size between the members constituting the laser irradiation system.

  In general, the diffusion angle of light transmitted through the diffusion member depends on the average size and shape of the speckle pattern. The higher the speckle pattern height and the narrower the pitch, that is, the higher the aspect ratio, the larger the diffusion angle. The size of the speckle pattern can be measured by, for example, an SEM (scanning electron microscope) or an ultra-deep microscope.

  Further, the unit structure constituting the concavo-convex structure of the diffusing member 13 is not limited to an isotropic one, and an anisotropic one can be formed, and a concavo-convex structure in which isotropic and anisotropy are combined. You can also If the speckle pattern is an ellipse with the horizontal axis as the major axis, anisotropic diffusivity is obtained, and the vertical diffusion angle is increased. This isotropic or anisotropic adjustment can be formed by changing the size and shape of the diffusion plate and aperture.

  After obtaining the concave / convex original molds of several types of diffusion patterns by the above method, they are arranged in a predetermined shape to obtain the submaster of the diffusion member 13 according to the present embodiment. A metal master mold to which a speckle pattern is transferred is manufactured by depositing a metal on the sub master by a method such as electroforming.

  The metal master mold may be a flat plate or a roll obtained by forming the flat plate into a cylindrical shape. In the case of a roll, a master seam is generated in a normal diffusing member, and the productivity and quality of the sheet are reduced by this seam. However, in the diffusing member 13 according to the present embodiment, there is a master seam. However, by making the boundary line into a region having a shape that can be matched with the master seam, the seam can be made inconspicuous. Further, even if there is a seam, the optical characteristics are not deteriorated.

  Next, a photosensitive resin is applied on a light-transmitting substrate sheet, and ultraviolet light is irradiated using a master mold to transfer and form a concavo-convex structure with a speckle pattern.

  Ultraviolet rays are irradiated from the back surface of the base material sheet having light permeability, thereby forming a cured photosensitive resin layer having a concavo-convex structure transferred to the boundary surface between the base material sheet and the master mold.

  As the base sheet having light transmittance, a material that transmits ultraviolet rays can be used. For example, a glass sheet or a resin sheet of polyester, polycarbonate, triacetyl cellulose, or the like is preferably used.

  The diffusion angle of the diffusing member 13 can be controlled by changing the pitch, height, and aspect ratio of the concavo-convex structure, but can also be controlled by changing the refractive index of the photosensitive resin layer that is cured by ultraviolet rays.

  After obtaining the base sheet having the concavo-convex structure as described above, the base sheet is made of a light-transmitting material and a predetermined adhesive material or heat is used for a predetermined substrate having supportability. Thus, the diffusion member may be bonded together.

  As the substrate, for example, a translucent material having a total light transmittance of 70% or more as defined in JIS K7361-1, such as glass, polyethylene terephthalate, polymethyl methacrylate, and polycarbonate can be preferably used.

  The diffusing member 13 may also be formed by placing the above-described master mold in a predetermined molding machine and performing injection molding with a transparent resin such as polymethyl methacrylate, polycarbonate, polystyrene, or cycloolefin polymer using the molding machine. Can be manufactured. According to this injection molding method, a bonding step with a substrate is not required, the transfer rate of the concavo-convex structure is high, and the strength of the molded product is also high, so that it is preferably used for lighting applications.

  FIG. 8 is a schematic diagram illustrating an example of the positional relationship between the first to third regions A1 to A3 of the diffusing member 13 and the point light source 12. 8A shows the positional relationship between the diffusing member 13 in a plan view of the diffusing member 13, and the light emitting unit 14 and the projection range 15 of the point light source 12, and FIG. 8B shows the diffusing member shown in FIG. 8A. 13 is a schematic perspective view of a part of FIG. As shown in FIGS. 8A and 8B, in the illumination device according to the present embodiment, when the light exit surface of the diffusing member 13 is viewed from the front, the projection range 15 of at least half the light emitting units 14 of the all-point light source 12 is used. It is preferable that at least two of the first region A1, the second region A2, and the third region A3 are included. With this configuration, since multiple surfaces of at least two regions having the same diffusion pattern appear to emit light with the same luminance, glare is suppressed because a single light source appears to exist. When the projection area 15 includes three areas of the first area A1, the second area A2, and the third area A3, the plurality of surfaces of the three areas having the same diffusion pattern are respectively Since it seems to emit light with the same brightness | luminance, it is more preferable.

  Even in the shape of the diffusing member 13 as shown in FIG. 5D, at least a part of the first area A1 and at least a part of the second area A2 are included in the projection range 15 of the light emitting unit 14 of the point light source 12. When the point light source 12 is arranged as described above, the glare suppressing effect is exhibited. Although it is preferable that all the point light sources 12 are arranged in this way, if there are less than half of all the point light sources 12 arranged in this way, depending on the viewing angle, the projection range 15 of the point light source 12 Since it appears that at least a part of the first region A1 and at least a part of the second region A2 are included, glare suppression can be achieved.

  Moreover, in the illuminating device which concerns on this Embodiment, at least all the area | regions which overlap with the projection area | region of the light emission part 14 of the point light source 12 among several 1st area | region A1 and several 2nd area | region A2. The area is preferably smaller than the area of the projection region of the light emitting part of the point light source 12. Thus, glare can be further suppressed by matching the relative positional relationship between the point light source 12 and the diffusing member 13.

  In the lighting device according to the present embodiment, the area of all the first regions A1 and second regions A2 among the plurality of first regions A1 and second regions A2 is the light emission of the point light source 12, respectively. It is preferable that the area is smaller than the area of the projection range 15 of the part. With this configuration, as shown in FIG. 9, regardless of the relative positional relationship between the point light source 12 and the diffusing member 13, at least one of the first areas A1 is always in the projection range 15 of the light emitting part of the point light source 12. Part and at least a part of the second region A2 are included, so that it is not necessary to perform relative alignment between the diffusing member 13 and the point light source 12 in order to achieve a glare suppressing effect.

  The diffusion member 13 according to the present embodiment can be used as a blind film for window pasting as a diffusion sheet formed in a sheet shape and laminated with an adhesive layer on one side. In this case, the uneven structure on the surface of the diffusing member 13 does not necessarily have to be formed on the entire surface. That is, among the regions, there may be a region that is flat without any unevenness. The presence of a flat region allows the outside to be seen from the inside through the portion, and the portion of the pattern that diffuses the light can be blinded from the outside. Moreover, since the light transmittance is higher than that of the sheet mixed with the diffusing agent, the indoor brightness is not impaired.

  As described above, in the diffusing member according to the above embodiment, the first region A1 and the second region A2 are formed by the uneven structure provided in the first region A1 and / or the second region A2. Indicate different diffusion patterns, the incident light incident from the light incident surface side of the diffusing member 13 is dispersed at different diffusion angles by the first region A1 and the second region A2 and emitted from the light output surface side. . Thereby, since the brightness | luminance of the area | region near the point light source 12 in the diffusion member 13 can be reduced, it becomes possible to suppress generation | occurrence | production of a glare also in the illuminating device using a point light source with a high brightness | luminance. In addition, since glare is suppressed by the difference in diffusion pattern between the first region A1 and the second region A2, it is possible to suppress a decrease in the total luminous flux.

  In particular, in the diffusing member according to the above embodiment, the uneven structure provided in the first region A1 and the second region A2 allows light to be transmitted without reducing the light transmittance within the main surface of the diffusing member 13. Since the occurrence of glare can be suppressed by diffusion, the light utilization efficiency can be increased, and the decrease in the total luminous flux of transmitted light can be effectively suppressed. For this reason, compared with a conventionally known diffuser plate containing a diffusing agent or a diffuser member with partially reduced permeability, the light emitted from the light source and transmitted through the diffuser plate is emitted. It is possible to suppress a decrease in the total luminous flux.

  In the diffusing member according to the above embodiment, by providing different first and second regions in a desired region in the main surface of the diffusing member 13, the permeability in the main surface of the diffusing member 13 is improved. Since the occurrence of glare can be suppressed without being reduced, the occurrence of glare can be suppressed even when, for example, play of the lighting device with respect to the diffusion member 13 or deformation due to bending or the like occurs in the diffusion member 13. For this reason, the effect of suppressing the occurrence of glare is not impaired even when a relative positional deviation between the light source and the diffusing member 13 occurs as compared with the conventional illumination device.

  Hereinafter, examples and comparative examples performed for clarifying the effects of the present invention will be described in detail. In addition, this invention is not limited at all by the following examples and comparative examples.

(Diffusion member)
By controlling the speckle pattern, a master mold having various uneven structures formed on the surface was produced. A prototype of a diffusion pattern in which a speckle pattern was formed by previously irradiating a photoresist with a laser beam through a lens, a diffusion plate, an aperture, and a mask by interference exposure. By changing the size of the diffuser and the aperture, several types of concave and convex masters with different diffusion patterns of emitted light were created, and masters arranged as the shapes of the respective regions of the respective diffusing members in the embodiments described below were prepared. Created. Next, using this master mold, an uneven structure made of an ultraviolet curable resin was formed on a polyethylene terephthalate resin film having a thickness of 250 μm to produce a diffusion member.

[Diffusion angle of diffusion member]
The surface on which the concavo-convex structure of the diffusion member produced as described above was formed was used as the light exit surface of the lighting device. The angle distribution of the transmitted light intensity with respect to the light incident in the normal direction of the surface of the diffusion member with the concavo-convex structure is measured with a goniophotometer (GC 5000L, manufactured by Nippon Denshoku Industries Co., Ltd.), and the diffusion angle of the diffusion member Got.

  Example 1 to Example 5 and Comparative Example 1 to Comparative Example 6 were evaluated using the lighting devices described below.

[Lighting device]
A white polyester resin reflective sheet (Furukawa Electric Co., Ltd., MCPET (registered trademark)) is pasted on the aluminum die-cast substrate surface, and a 10 mm high wall is formed on the periphery of the substrate surface by the reflective sheet. A lighting device having the configuration shown in FIG. 1A was produced.

  As the point light source 12, as shown in FIG. 10, a 1 W LED light source having dimensions of 5 mm in length and 1 mm in height and having a light emitting part of 4 mmφ is arranged with 8 pieces in length and 8 pieces in a 45 mm pitch on the substrate surface. A total of 64 pieces were arranged in a square lattice pattern.

  Furthermore, as shown in FIG. 11, a diffusing member, which will be described later, is arranged at a predetermined distance h from the substrate surface, and the overall illumination device is approximately 360 mm × 360 mm.

[Light distribution measurement]
(1/2 beam angle)
The light distribution measurement was performed using an illuminometer (Lux Hitester, manufactured by Hioki Electric Co., Ltd.).
The absolute value of the angle formed between the normal direction of the light emitting surface of the lighting device and the direction of the light beam emitted from the light emitting surface of the lighting device is as follows with respect to the center position of the light emitting surface of the lighting device. Set by rotating.

Specifically, the horizontal position d is set to be 4000 mm apart from the center position of the light exit surface of the illumination device that measures the illuminometer, and the illumination device is rotated every 5 degrees in the horizontal direction while the vertical direction of the light exit surface. From the illuminance value E (lx) measured in the range of the horizontal rotation angle γ from −90 ° to 90 ° with the horizontal angle d (m) as 0 °, the luminous intensity I ( The light distribution characteristic of the lighting device was obtained in terms of cd).
I = E · d ² (Formula 1)
Here, an angle that is twice the absolute value of the angle formed between the normal direction of the light exit surface of the illuminating device and the direction in which the luminous intensity is ½ of the luminous intensity in the normal direction is defined as a ½ beam angle.

  The 1/2 beam angle was measured while rotating the light source every 1 degree so that the luminous intensity value in the normal direction of the light exit surface of the lighting fixture becomes 1/2.

  In this case, when the light distribution characteristic and the 1/2 beam angle are measured, the shape of the light exit surface of the illuminating device is a square, and therefore a line segment passing through the center of the square and parallel to any of the four sides. Minutes were measured as the axis of rotation.

[Light distribution measurement]
(60 degree luminous intensity)
From the result of the light distribution measurement, when the vertical direction of the light emitting surface of the lighting device is 0 degree, the light intensity in the oblique 60 degree direction is set as one of the evaluation criteria of the oblique glare. As a relative value when the luminous intensity in the direction of 60 degrees when the diffusion panel or the like does not exist only with the LED light source is set to 100, the luminous intensity in the direction of 60 degrees of each optical sheet was calculated and compared. In ceiling lighting used in offices and the like, it is preferable to reduce the amount of light emitted in the wide-angle direction from 60 degrees obliquely.

(Total luminous flux) Measurement with integrating sphere Total luminous flux was measured using an integrating sphere type total luminous flux measurement system. As the integrating sphere, a 1000 mmφ integrating whole sphere (manufactured by Labsphere, CSLMS LED 4061) was used, and the measurement was performed with the illuminating device placed at the center of the integrating sphere with the light exit surface facing away from the receiving optical fiber. In addition, the measured value of the total luminous flux was expressed as a relative value with the measured value of Comparative Example 3 (in the case where only the LED light source is used and no diffusing panel or the like is present) as 100.

[Glare evaluation]
Glare was evaluated while rotating the illumination device in the same manner as the light distribution measurement.
The front glare looks directly at the lighting device from a distance of 4000 mm in the vertical direction (0 degree) of the light emitting surface of the lighting device, and the oblique glare looks from a distance of 4000 mm in the diagonal direction of the light emitting surface (azimuth angle of 30 to 60 degrees). The lighting device was directly viewed and evaluated visually.
○: Not uncomfortable (withstands direct viewing, LED bright spots are blurred / appear to be multiple)
Δ: Slightly uncomfortable (LED bright spots are slightly blurred)
×: Uncomfortable (LED bright spots are conspicuous and cannot withstand direct viewing)

〔Comprehensive judgment〕
Negative determination elements in the evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, the front glare, and the oblique glare were set, and comprehensive determination was performed using the number of negative determination elements according to the following criteria as an index.
(Negative judgment element)
Total luminous flux (relative value): less than 95
Luminous intensity in the direction of 60 degrees: 75 or more
Glare evaluation: × (equivalent to 2 elements), △ (equivalent to 1 element)
(Criteria)
A determination: No negative determination element.
B determination: One negative determination element.
C determination: Two or more negative determination elements.

[Example 1]
In the illuminating device of Example 1, a diffusion member having two types of diffusion angle levels and regularly arranging regions having different diffusion angles as shown in FIG. 5E was used.

  The level of the diffusion angle is 10 degrees and 40 degrees, and a plurality of second areas A2 having a diffusion angle of 40 degrees of 2 mm square are 90 mm long by 90 mm wide at a pitch of 4 mm in the first area A1 having a diffusion angle of 10 degrees. Diffusion members that are distributed individually were produced and placed in a lighting device. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 1 are shown in Table 1 below.

  In this embodiment, compared with the case where no diffusing member is provided, the front glare and the oblique glare can be suppressed by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4%. As a result, it was found that it has practically good characteristics.

  In this embodiment, based on two different diffusion angle levels, as shown in FIG. 12A, the light distribution characteristics of the diffusing member that is an intermediate diffusion angle between the two diffusion angles are reproduced, and glare suppression is achieved. The effect could be improved.

[Example 2]
In the illuminating device of Example 2, a diffusion member having two types of diffusion angle levels and regularly arranging regions having different diffusion angles as shown in FIG. 5F was used.

  The diffusion angle levels are 10 degrees and 40 degrees, and a plurality of second areas A2 having a diffusion angle of 40 degrees of 3 mm square and 90 mm length × width 90 degrees in a pitch of 4 mm in the first area A1 having a diffusion angle of 10 degrees. Diffusion members that are distributed individually were produced and placed in a lighting device. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 2 are shown in Table 1 below.

  In this embodiment, compared with the case where no diffusing member is provided, the front glare and the oblique glare can be suppressed by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4%. As a result, it was found that it has practically good characteristics.

  In this embodiment, based on two different diffusion angle levels, as shown in FIG. 12B, the light distribution characteristics of the diffusing member such that the diffusion angle is intermediate between the two diffusion angles are reproduced, and the glare is suppressed. The effect could be improved.

Example 3
In the illuminating device of Example 3, a diffusion member having three levels of diffusion angles and having a square shape of 5 mm square in each region having a different diffusion angle as shown in FIG. 7A was used.

  The diffusion angle levels are a first area A1 with a diffusion angle of 1 degree, a second area A2 with a diffusion angle of 11 degrees, and a third area A3 with a diffusion angle of 30 degrees, and the projection ranges of the light emitting portions of all LED light sources. It arrange | positioned in the illuminating device so that at least 2 area | region of 1st area | region A1, 2nd area | region A2, and 3rd area | region A3 might be included in it. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 3 are shown in Table 1 below.

  In this embodiment, compared with the case where no diffusing member is provided, the front glare and the oblique glare can be suppressed by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4%. As a result, it was found that it has practically good characteristics.

  In the present embodiment, as shown in FIG. 12C, compared with the case where the diffusion angle is uniform in the main surface, there are more light emission components in the wide angle direction of 30 ° to 45 °, and the wide surface is uniformly irradiated. Therefore, a preferable form as a lighting device used for the ceiling surface could be realized. That is, a light distribution characteristic that cannot be realized by a diffusion member having a uniform diffusion angle in the main surface was obtained.

Example 4
In the illuminating device of Example 4, diffusion equipment having three types of diffusion angle levels and having a square shape of 5 mm square in each region having different diffusion angles as shown in FIG. 7A was used.

  The diffusion angle levels are a first area A1 with a diffusion angle of 4 degrees, a second area A2 with a diffusion angle of 20 degrees, and a third area A3 with a diffusion angle of 42 degrees, and the projection ranges of the light emitting portions of all LED light sources. It arrange | positioned in the illuminating device so that at least 2 area | region of 1st area | region A1, 2nd area | region A2, and 3rd area | region A3 might be included in it. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 4 are shown in Table 1 below.

  In this embodiment, compared with the case where no diffusing member is provided, the front glare and the oblique glare can be suppressed by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4%. As a result, it was found that it has practically good characteristics.

  In this embodiment, as shown in FIG. 12D, the illumination device is configured such that the light emission component in the direction of 5 degrees is larger than the light emission component in the direction of 0 degrees as compared with the diffusion angle uniform in the main surface. It became possible to selectively irradiate a certain range in the direct downward direction. That is, a light distribution characteristic that cannot be realized by a diffusion member having a uniform diffusion angle in the main surface was obtained.

Example 5
In the illuminating device of Example 5, a diffusion member having three types of diffusion angle levels and having a square shape of 5 mm square in each of the regions having different diffusion angles as shown in FIG. 7A was used.

  The diffusion angle levels are a first area A1 with a diffusion angle of 11 degrees, a second area A2 with a diffusion angle of 29 degrees, and a third area A3 with a diffusion angle of 41 degrees, and the projection ranges of the light emitting sections of all LED light sources. It arrange | positioned in the illuminating device so that at least 2 area | region among 1st area | region A1, 2nd area | region 2, and 3rd area | region A3 might be included in it. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 5 are shown in Table 1 below.

  In this embodiment, compared with the case where no diffusing member is provided, the front glare and the oblique glare can be suppressed by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4%. As a result, it was found that it has practically good characteristics.

  In this embodiment, as shown in FIG. 12E, the light emission component in the 10 degree direction is made larger than the light emission component in the 0 degree direction as compared with the case where the diffusion angle is uniform in the main surface. It is possible to selectively irradiate a certain range directly below the apparatus. That is, a light distribution characteristic that cannot be realized by a diffusion member having a uniform diffusion angle in the main surface was obtained.

Example 6
In the illuminating device of Example 6, a diffusion member having three types of diffusion angle levels and each region having a different diffusion angle having a square shape of 2.5 mm square as shown in FIG. 7A was used.

  The diffusion angle levels were the first region A1 with a diffusion angle of 1 degree, the second region A2 with a diffusion angle of 31 degrees, and the third region A3 with a diffusion angle of 45 degrees, and these were arranged in the lighting device. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 6 are shown in Table 1 below.

  In the present embodiment, the light distribution characteristics as shown in FIG. 12F are shown, and the front glare and the light source are reduced by the pseudo multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4% as compared with the case where the diffusing member is not provided. It was found that oblique glare can be suppressed, and that the lighting device has practically good characteristics.

Example 7
In the illuminating device of Example 7, a diffusion member having three types of diffusion angle levels and having a 2.5 mm square shape in each region having different diffusion angles as shown in FIG. 7A was used.

The diffusion angle levels were the first region A1 with a diffusion angle of 1 degree, the second region A2 with a diffusion angle of 20 degrees, and the third region A3 with a diffusion angle of 48 degrees, and these were arranged in the lighting device. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Example 7 are shown in Table 1 below.

  In this embodiment, the light distribution characteristic as shown in FIG. 12G is shown, and the front glare and the light source are reduced by quasi-multiple lighting of the light source while suppressing the decrease in the total luminous flux to about 4% as compared with the case where the diffusion member is not provided. It was found that oblique glare can be suppressed, and that the lighting device has practically good characteristics.

[Comparative Example 1]
About the illuminating device in the comparative example 1, it evaluated without arrange | positioning anything on the light emission surface side of a light source. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Comparative Example 1 are shown in Table 2 below. The light distribution characteristics are shown in FIG. 13A. As a result, since the diffusing member is not disposed, the glare is very strong and uncomfortable when viewed from any direction.

[Comparative Example 2]
About the illuminating device in Comparative Example 2, a louver having a height of 10 mm and a lattice interval of 45 mm is made of a white polyester resin reflective sheet (manufactured by Furukawa Electric Co., Ltd., MCPET (registered trademark)), and a point light source is arranged. The evaluation was performed by arranging between each point light source on the substrate surface. The evaluation results of the total luminous flux, 60 degree luminosity and glare of Comparative Example 2 are shown in Table 2 below, and the light distribution characteristics are shown in FIG. 13B.

  As a result, although the luminous intensity in the 60-degree direction can be suppressed, the front glare and the oblique glare from the angle region inside the 60-degree direction cannot be suppressed. In addition, in order to suppress the luminous intensity in the direction of 60 degrees, it is necessary to adjust the height of the louver, and it is bulky.

[Comparative Example 3]
The lighting device in Comparative Example 3 is made of polystyrene having a thickness of 1.5 mm, contains 2000 ppm of silicone fine particles having a true specific gravity of 1.35 and an average particle diameter of 2 μm inside, and has a surface on which no irregularities are formed. The member was placed on the light exit surface side of the light source for evaluation. The evaluation results of the total luminous flux, the luminous intensity in the direction of 60 degrees, and the glare of Comparative Example 3 are shown in Table 2 below, and the light distribution characteristics are shown in FIG. 13C.

  As a result, although the glare was suppressed, the total luminous flux was reduced by about 6%, which proved unpreferable as a lighting device. Moreover, the luminous intensity in the direction of 60 degrees could not be sufficiently suppressed.

[Comparative Example 4]
The diffusion member used for the illumination device in Comparative Example 4 is made of polystyrene having a thickness of 1.5 mm, contains 8000 ppm of silicone fine particles having a true specific gravity of 1.35 and an average particle diameter of 2 μm inside, and has an uneven shape on the surface. Evaluation was carried out by placing the non-lighted one on the light exit surface side of the light source. The evaluation results of the total luminous flux, 60 degree luminosity and glare of Comparative Example 4 are shown in Table 2 below, and the light distribution characteristics are shown in FIG. 13D.

  As a result, although the glare was suppressed, the total luminous flux was reduced by about 9%, which proved unpreferable as a lighting device. Moreover, the luminous intensity in the direction of 60 degrees could not be sufficiently suppressed.

[Comparative Example 5]
About the illuminating device in the comparative example 5, the diffusion member which has the fine concavo-convex structure on the surface which shows a diffusion angle of 20 degrees on the whole surface by the same interference exposure method as an Example was produced and used. The evaluation results of the total luminous flux, 60 degree luminosity and glare of Comparative Example 5 are shown in Table 2 below, and the light distribution characteristics are shown in FIG. 13E. As a result, it was possible to reduce the luminous intensity in the direction of 60 degrees and to suppress the oblique glare satisfactorily, but it was somewhat uncomfortable because the front glare was felt a little.

[Comparative Example 6]
About the illuminating device in the comparative example 6, the diffusion member which has the fine concavo-convex structure on the surface which shows the diffusion angle of 40 degrees on the whole surface by the same interference exposure method as an Example was produced and used. The evaluation results of the total luminous flux, 60 degree luminosity and glare of Comparative Example 6 are shown in Table 2 below, and the light distribution characteristics are shown in FIG. 13F. As a result, it was possible to suppress front glare satisfactorily, but it was somewhat uncomfortable because a slight amount of oblique glare was felt.

  As shown in Table 1 and Table 2, the first region A1 and the second region A2 having different diffusion patterns, or the first region A1 and the second region A2 having different diffusion patterns, In the diffusing member according to Examples 1 to 7 having the third region A3, both front glare and oblique glare can be suppressed, and the total luminous flux is maintained at a high level.

  On the other hand, when the diffusing member is not provided, frontal and oblique glare is remarkable (Comparative Example 1). When the louver is provided, frontal glare can be suppressed, but oblique glare cannot be suppressed. (Comparative example 2). Moreover, although the generation of a constant glare could be suppressed by adding silicone fine particles, when the addition amount was small, frontal glare and oblique glare could not be sufficiently reduced (Comparative Example 3), and the addition amount was increased. In this case, the occurrence of front glare and oblique glare can be suppressed, but the total luminous flux is greatly reduced (Comparative Example 4). Furthermore, by providing a fine concavo-convex structure showing a predetermined diffusion angle on the entire surface of the diffusion member, either front glare or oblique glare could be reduced, but both front glare and oblique glare could be reduced. None (Comparative Example 5 and Comparative Example 6).

  INDUSTRIAL APPLICABILITY The present invention has an effect that it is possible to realize a diffusing member and an illuminating device that can suppress glare derived from a point light source with high luminance and suppress a decrease in the total luminous flux. Application to seats, ceiling lighting devices, etc. can be expected.

DESCRIPTION OF SYMBOLS 11 Support body 12 Point light source 13 Diffusion member 14 Light emission part 15 Projection range

Claims (11)

A diffusion member made of a light transmissive material and having a pair of main surfaces,
In the pair of main surfaces, at least one first region and a plurality of second regions provided adjacent to each other,
The first region and / or the second region includes a concavo-convex structure for diffusing light emitted from the first and second regions on at least one main surface of the pair of main surfaces,
A diffusion member characterized in that diffusion angles in the first and second regions are different from each other.   Each of the first and second regions includes a concavo-convex structure provided on at least one main surface of the pair of main surfaces and diffusing light emitted from the first and second regions. The diffusion member according to claim 1.   The diffusion member according to claim 1, wherein the pair of main surfaces of one of the first and second regions is flat.   The diffusing member according to any one of claims 1 to 3, wherein the plurality of second regions have the same shape.   The diffusion member according to claim 4, wherein the plurality of second regions are regularly arranged.   The diffusion member according to claim 3, wherein the diffusion member has a plurality of the first regions, and all of the first and second regions have the same shape.   When the light is incident vertically from the diffusion surface of the concavo-convex structure in the second region, and the diffusion angle of the light emitted when the light enters perpendicularly from the concavo-convex structure formation surface in the first region The diffusion angle of the light emitted to the light source is in the range of 0.1 degrees to 100 degrees, and is defined in any one of claims 1 to 2 and claims 4 to 6. Diffusion member.   An illuminating device comprising: at least one point light source; and the diffusing member according to any one of claims 1 to 7 provided in a light emission direction of light emitted from the point light source.   When the light exit surface of the diffusing member is viewed from the front, at least part of the first region and at least part of the second region are within the projection range of the light emitting units of at least half of the point light sources, respectively. The illumination device according to claim 8, wherein the illumination device is included.   Of the plurality of first regions and the plurality of second regions, at least the area of all the regions that overlap with the projection region of the light emitting unit of the point light source is the projection region of the light emitting unit of the point light source, respectively. The lighting device according to claim 8 or 9, wherein the lighting device is smaller than an area.   The area of all the areas among the plurality of first areas and the plurality of second areas is smaller than the area of the light emission projection part of the point light source, respectively. The illuminating device in any one of.

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