WO2015122434A1 - Light guide plate, and lighting device - Google Patents

Light guide plate, and lighting device Download PDF

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Publication number
WO2015122434A1
WO2015122434A1 PCT/JP2015/053764 JP2015053764W WO2015122434A1 WO 2015122434 A1 WO2015122434 A1 WO 2015122434A1 JP 2015053764 W JP2015053764 W JP 2015053764W WO 2015122434 A1 WO2015122434 A1 WO 2015122434A1
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WO
WIPO (PCT)
Prior art keywords
light
guide plate
main plane
light guide
emitted
Prior art date
Application number
PCT/JP2015/053764
Other languages
French (fr)
Japanese (ja)
Inventor
恵一 望月
尚志 岩本
史紀 高橋
Original Assignee
日東光学株式会社
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Filing date
Publication date
Application filed by 日東光学株式会社 filed Critical 日東光学株式会社
Publication of WO2015122434A1 publication Critical patent/WO2015122434A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F21V3/04—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0038—Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/004—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles
    • G02B6/0043—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles provided on the surface of the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
    • G02B6/0061—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to provide homogeneous light output intensity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
    • F21V13/12—Combinations of only three kinds of elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F21V3/04—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings
    • F21V3/049—Patterns or structured surfaces for diffusing light, e.g. frosted surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00—Planar light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • the present invention relates to a light guide plate and a lighting device.
  • Patent Documents 1 to 3 there is known a light guide plate that emits light emitted from an LED (Light Emitting Diode) light source as a surface light source from an emission surface.
  • LED Light Emitting Diode
  • JP 2010-218693 A JP-A-9-101521 JP-A-9-61631
  • an object of the present invention is to provide a light guide plate and an illumination device that can emit light emitted from a light source and emitting light with uniform brightness on the emission surface and improvement of emission efficiency.
  • the light guide plate of the present invention receives light emitted from a plurality of light sources arranged in parallel, and is incident from the first end surface and the second end surface arranged to face each other, and from each end surface.
  • the first main plane and the second main plane arranged opposite to each other from which the light from the plurality of light sources emits, and the light emitted from the second main plane arranged in the first main plane are opposed to the second main plane.
  • the first light diffusing portion is formed, and the first light diffusing portion formed on any one of the main planes is a point-like first light formed by a set of many protrusions or holes.
  • the first light diffusing portion that is the diffusing portion and is formed on the other main plane has a plurality of length directions. And it is linear first light diffusing portion formed at a collection of a large number of ridges or grooves parallel to the array direction of the source.
  • the dotted first light diffusing portion is formed on the second main plane, and the linear first light diffusing portion is formed on the first main plane.
  • the dotted first light diffusing portion and the linear first light diffusing portion are formed in a range outside 70% of the irradiation angle of the light source.
  • the light guide plate may be provided on each main plane between the first light diffusion portion formed on the first end surface side and the first light diffusion portion formed on the second end surface side.
  • the second light diffusing portion formed on the main plane on the side where the two light diffusing portions are formed and the point-like first light diffusing portion is formed as the first diffusing portion is formed by a set of many protrusions or holes.
  • the second light diffusing portion formed on the main plane on the side where the linear first light diffusing portion is formed as the first diffusing portion has a length direction parallel to the light source. It is assumed that the linear second light diffusing portion is formed by a set of a large number of ridges or grooves parallel to each other.
  • the dotted second light diffusion portion has a higher formation density as the distance from the illumination optical axis of the light source is longer.
  • the light guide plate has a distance between the first end surface and the second end surface of 30 mm or more and 80 mm or less.
  • the light guide plate is an LED in which the light source is an LED chip disposed in a cup-shaped reflection plate, and the distance between the first main plane and the second main plane of the light guide plate is the reflection plate. It is assumed that the opening diameter is not less than three times the opening diameter.
  • the light guide plate is formed such that the first end surface and the second end surface are inclined surfaces in which portions corresponding to the regions are spaced apart from each other from the second main plane toward the first main plane.
  • the light guide plate includes a light diffusing plate having a light incident surface on which light emitted from the first main plane is incident and a light emitting surface from which light incident from the light incident surface is emitted.
  • the diffuser plate is disposed on the main plane side, and the diffusion plate protrudes toward the first main plane side, and is provided at a position facing at least the peripheral portion on each end face side of the peripheral portion of the first main plane of the light guide plate. It has a ridge part which has a peripheral light incident surface which is a light incident surface in which the light radiate
  • the light guide plate is a light shield that restricts the amount of light emitted from the peripheral portion from entering the peripheral light incident surface between each peripheral portion and the peripheral light incident surface of the ridge. Parts are provided.
  • the illumination device of the present invention includes the above-described light guide plate and a light source that makes light incident on an end surface of the light guide plate.
  • FIG. 2 is a cross-sectional view illustrating a cross-sectional structure of the lighting device taken along a cutting line AA illustrated in FIGS. It is the top view which looked at the illuminating device from the light-projection surface side. It is the perspective view which looked at the illuminating device of the state which removed the reflecting plate from the downward direction.
  • FIG. 8 is a cross-sectional view showing a cross-sectional structure of the illumination device taken along a cutting line DD shown in FIG. 7.
  • the illumination device 1 and the light guide plate 2 according to embodiments of the present invention will be described with reference to the drawings.
  • the light guide plate 2 will be described together with the configuration of the lighting device 1.
  • FIG. 1 is a perspective view showing a configuration of a lighting device 1 according to the first embodiment of the present invention
  • an upper stage (A) is a perspective view of the lighting apparatus 1 viewed from the right rear side
  • a lower stage (B ) Is a perspective view of the illumination device 1 as viewed from the right front.
  • FIG. 2 is a cross-sectional view showing a cross-sectional structure of the lighting device 1 taken along the cutting line AA shown in FIGS. In FIG. 2, hatching is omitted for easy understanding of the configuration.
  • FIG. 3 is a plan view of the illumination device 1 as seen from the light exit surface side.
  • FIG. 4 is a perspective view of the lighting device 1 with the reflection plate 5 removed, as viewed from below.
  • the light guide direction of the light guide plate 2 is the front-rear direction
  • the arrow X1 direction is the front (front side)
  • the arrow X2 direction is the rear (rear side).
  • the parallel direction of LED 3A and LED 3B will be described as the left-right direction
  • the arrow Y1 direction will be left (left side)
  • the arrow Y2 direction will be right (right side).
  • the light emission direction of the illuminating device 1 is set as an upward direction
  • the arrow Z1 direction is upward (upper side)
  • the arrow Z2 direction is downward (lower side).
  • the lighting device 1 includes a light guide plate 2 and LEDs 3A and 3B as light sources.
  • the light guide plate 2 includes a light guide plate main body 4 and a reflection plate 5 that constitutes a reflection means, and the light guide plate main body 4 is disposed above the reflection plate 5.
  • a plurality of LEDs 3 ⁇ / b> A are provided on the end face 6 on the rear side of the light guide plate body 4.
  • the LEDs 3A are arranged in parallel in the left-right direction.
  • the front end face 7 of the light guide plate body 4 is provided with a plurality of LEDs 3B, and the LEDs 3B are also juxtaposed in the left-right direction, like the LEDs 3A. That is, the LED 3A and the LED 3B disposed with respect to the light guide plate body 4 are disposed on the opposite side with the light guide plate body 4 sandwiched in the front-rear direction.
  • a CCFL Cold Cathode Fluorescent Lamp
  • a light bulb for example, an incandescent light bulb
  • a fluorescent light or the like
  • LEDs are superior to other light sources in that they consume less power and generate more heat, and are easier to miniaturize. Therefore, it is preferable to use an LED as the light source.
  • the light guide plate body 4 has a solid structure formed of, for example, a transparent acrylic resin.
  • the light guide plate main body 4 has a rectangular shape in plan view, presents a plate-like body flattened in the vertical direction as a whole, an end surface 6 on which the LEDs 3A are disposed, an end surface 7 on which the LEDs 3B are disposed, and a first main plane 8 And a second main plane 9.
  • a dotted light diffusion portion 10A as a dotted first light diffusion portion is formed in the peripheral portion 8A on the end face 6 side.
  • the dotted light diffusing portion 10A is formed at a position corresponding to between adjacent LEDs 3A of a plurality of LEDs 3A (see FIG. 1A) provided for the light guide plate body 4.
  • the dotted light diffusion portion 10A is also formed on the left and right edges of the peripheral portion 8A.
  • the dotted light diffusing portion 10A has a shape in which the width in the left-right direction becomes narrower from the rear toward the front. That is, the point light diffuser 10A has a triangular shape with the end face 6 side as a base.
  • a dotted light diffusion portion 10 ⁇ / b> B as a dotted first light diffusion portion is formed on the peripheral portion 8 ⁇ / b> B on the end surface 7 side.
  • the dotted light diffusing portion 10B is formed at a position corresponding to between adjacent LEDs 3B of a plurality of LEDs 3B (see FIG. 1B) provided for the light guide plate body 4.
  • the point light diffusion part 10B is also formed on the left and right edges of the peripheral edge part 8B.
  • the dotted light diffusion portion 10B has a shape in which the width in the left-right direction becomes narrower from the front to the rear. That is, the dotted light diffusion portion 10B has a triangular shape with the end face 7 side as a base.
  • a point light diffusion portion 11 as a point second light diffusion portion is formed between the point light diffusion portion 10 ⁇ / b> A and the point light diffusion portion 10 ⁇ / b> B.
  • the dotted light diffusing portion 11 is formed between the dotted light diffusing portion 10A and the dotted light diffusing portion 10B, which are arranged to face each other in the front-rear direction.
  • the spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 perform a roughening process at positions corresponding to the spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 on the first main plane 8. It is the uneven surface formed by.
  • the spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 have, for example, a concavo-convex surface formed by a set of many holes.
  • the spot-like light diffusing parts 10A and 10B and the spot-like light diffusing part 11 may form a concavo-convex surface with a set of many protrusions.
  • a linear light diffusion portion 12 ⁇ / b> A as a linear first light diffusion portion is provided on the peripheral portion 9 ⁇ / b> A on the end surface 6 side. Is formed.
  • the linear light diffusion portion 12A is formed at a position corresponding to between adjacent LEDs 3A of a plurality of LEDs 3A (see FIG. 1A) provided for the light guide plate body 4.
  • the linear light diffusion portion 12A is also formed on the left and right edges of the peripheral portion 9A.
  • the linear light diffusion portion 12A has a shape in which the width in the left-right direction becomes narrower from the rear toward the front. That is, the linear light diffusion portion 12A has a triangular shape with the end face 6 side as a base.
  • a linear light diffusion portion 12B as a linear first light diffusion portion is formed in the peripheral portion 9B on the end face 7 side.
  • the linear light diffusion portion 12B is formed at a position corresponding to between adjacent LEDs 3B of a plurality of LEDs 3B (see FIG. 1B) provided for the light guide plate body 4.
  • the linear light diffusion portion 12B is also formed on the left and right edges of the peripheral portion 9B.
  • the linear light diffusion portion 12B has a shape in which the width in the left-right direction becomes narrower from the front toward the rear. That is, the linear light diffusing portion 12B has a triangular shape with the end face 7 side as a base.
  • the linear light diffusion portions 12A and 12B can be formed by a plurality of grooves 12AA and 12BB formed in the second main plane 9.
  • the grooves 12AA and 12BB are grooves whose longitudinal direction is parallel to the parallel direction of the plurality of LEDs 3A and 3B. That is, the grooves 12AA and 12BB are grooves that are parallel to the end faces 6 and 7 and whose longitudinal direction is formed in the left-right direction.
  • a linear light diffusion portion 13 (FIG. 2) as a linear second light diffusion portion between the linear light diffusion portion 12A and the linear light diffusion portion 12B. , 4).
  • the linear light diffusion portion 13 can be formed by a plurality of grooves 13A formed in the second main plane 9.
  • the groove 13A is a groove whose longitudinal direction is parallel to the parallel direction of the plurality of LEDs 3A and 3B. That is, the groove 13 ⁇ / b> A is parallel to the end surfaces 6 and 7 and is formed from one end edge in the left-right direction of the second main plane 9 to the other end edge.
  • the grooves 12AA, 12BB and the groove 13A are formed, for example, by cutting the first main plane 8 or the second main plane 9, or when the light guide plate body 4 is manufactured by a mold, simultaneously with the molding. It can also be formed as a mold transfer shape. Moreover, you may form the linear light-diffusion parts 12A and 12B and the linear light-diffusion part 13 with a protruding item
  • the groove widths and depths of the grooves 12AA and 12BB are wider and deeper than the groove 13A. Further, the interval between adjacent grooves 12AA (formation pitch in the front-rear direction of the plurality of grooves 12AA) is formed denser than the interval adjacent to each other groove 13A (formation pitch in the front-rear direction of the plurality of grooves 13A). Yes. The formation pitch in the front-rear direction of the plurality of grooves 12BB is also formed denser than the formation pitch in the front-rear direction of the plurality of grooves 13A.
  • the reflecting plate 5 has a reflecting surface 5A formed on the surface of the light guide plate body 4 facing the second main plane 9 by, for example, aluminum vapor deposition.
  • the reflecting plate 5 preferably has a shape facing the entire surface of the second main plane 9. That is, it is preferable that the reflecting plate 5 has the same shape as that of the light guide plate main body 4 in a plan view or is slightly larger in outline than the second main plane 9. Thereby, the light quantity which reflects the light radiate
  • the reflecting plate 5 is disposed so that the reflecting surface 5A faces the second main plane 9 of the light guide plate body 4 in parallel.
  • the second main plane 9 of the light guide plate main body 4 is attached with a reflecting sheet, or the second main plane 9 is directly subjected to, for example, aluminum vapor deposition, so that the second A reflecting surface may be formed outside the main plane 9 to serve as reflecting means.
  • a linear light diffusion portion 13 is formed on the second main plane 9.
  • Each of the plurality of grooves 13 ⁇ / b> A forming the linear light diffusion portion 13 has an inclined surface 13 ⁇ / b> B with an inclined surface facing the end surface 6 side.
  • the inclined surface 13B By forming the inclined surface 13B on the second main plane 9, the light emitted from the LED 3A can be compared with the case where the area of the linear light diffusion portion 13 of the second main plane 9 is composed of only a plane. The amount of light totally reflected by the two main planes 9 can be reduced, and the amount of light transmitted through the second main plane 9 can be increased.
  • the amount of light emitted from the LED 3A can be increased from the second main plane 9 toward the reflecting surface 5A.
  • the light emitted to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate main body 4, and is emitted upward from the first main plane 8. Therefore, the amount of light emitted from the first main plane 8 can be increased by forming the linear light diffusion portion 13 on the second main plane 9.
  • the area outside the irradiation range between the irradiation ranges of the adjacent LEDs 3B tends to be low in luminance.
  • the area where the dotted light diffusing portion 10B is formed tends to be an area outside the irradiation angle range of the adjacent LED 3B and LED 3B, and the luminance tends to be low. Focusing on this point, in the light guide plate 2, the linear light diffusion portion 12B is formed on the peripheral edge portion 9B on the end surface 7 side of the second main plane 9, thereby improving the luminance of the region between the LED 3B and the LED 3B. ing.
  • each of the plurality of grooves 12BB forming the linear light diffusion portion 12B has an inclined surface 12BC with the inclined surface facing the end surface 6 side.
  • the inclined surface 12BC is formed, so that the light emitted from the LED 3A is entirely emitted from the second main plane 9.
  • the amount of light reflected can be reduced, and the amount of light transmitted through the second main plane 9 can be increased.
  • the light emitted from the region where the linear light diffusing portion 12B is formed to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate body 4, and is mainly dotted light on the first main plane 8.
  • the light is emitted upward from the region including the diffusion portion 10B. Therefore, by forming the linear light diffusion portion 12B on the second main plane 9, the amount of light emitted from the region including the point light diffusion portion 10B on the first main plane 8 can be increased.
  • the light emitted from the LED 3B enters the light guide plate body 4 from the end face 7 of the light guide plate body 4, and a part of the light is guided directly from the first main plane 8 in the same manner as the light emitted from the LED 3A.
  • the other part of the light emitted above the optical plate body 4 is emitted from the second main plane 9 toward the reflection plate 5, reflected by the reflection surface 5A, and transmitted through the light guide plate body 4 again to the first.
  • the light is emitted upward from the main plane 8.
  • Each of the plurality of grooves 13A forming the linear light diffusion portion 13 has an inclined surface 13C with the inclined surface facing the end surface 7 side. Therefore, similarly to the above-described inclined surface 13B, the amount of light emitted from the LED 3B is totally reflected on the second main plane 9, and the amount of light emitted from the second main plane 9 toward the reflecting surface 5A is increased. Can do.
  • the light emitted to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate body 4, and is emitted upward from the first main plane 8, so that the amount of light emitted from the first main plane 8 is reduced. Can be increased.
  • the area outside the irradiation range between the irradiation ranges of the adjacent LEDs 3A tends to be low in luminance.
  • the area where the dotted light diffusion portion 10A is formed is likely to be an area outside the range of the irradiation angle of the adjacent LED 3A and LED 3A, and the luminance is likely to be low. Focusing on this point, in the light guide plate 2, the linear light diffusion portion 12A is formed on the peripheral edge portion 9A on the end surface 6 side of the second main plane 9, thereby improving the luminance of the region between the LED 3A and the LED 3A. ing.
  • each of the plurality of grooves 12AA forming the linear light diffusion portion 12A has an inclined surface 12AC with the inclined surface facing the end surface 7 side.
  • the inclined surface 12AC is formed so that the light emitted from the LED 3B is totally reflected by the second main plane 9.
  • the amount of light transmitted can be reduced, and the amount of light transmitted through the second main plane 9 can be increased.
  • the light emitted from the region where the linear light diffusing portion 12A is formed to the reflecting surface 5A side is reflected by the reflecting surface 5A, passes through the light guide plate body 4, and is mainly point-like light on the first main plane 8.
  • the light is emitted upward from the region including the diffusion portion 10A. Therefore, by forming the linear light diffusion portion 12A on the second main plane 9, the amount of light emitted from the region including the point light diffusion portion 10A on the first main plane 8 can be increased.
  • the light incident on the light guide plate body 4 from the LEDs 3A and 3B is formed by forming the linear light diffusion portion 12A, the linear light diffusion portion 12B, and the linear light diffusion portion 13 on the second main plane 9. Is emitted from the first main plane 8.
  • the linear light diffusion portions 12A and 12B are formed, it is possible to improve the luminance of the low-luminance region outside the irradiation angle range of the adjacent LED 3A and LED 3B, and the luminance of the first main plane 8 Can be made uniform.
  • the light in the light guide plate body 4 is diffused by the linear light diffusing portion 12A, the linear light diffusing portion 12B, or the linear light diffusing portion 13 when emitted from the second main plane 9 to the reflecting surface 5A.
  • the state is emitted.
  • the linear light diffusion portion 12A, the linear light diffusion portion 12B, or the linear light diffusion is used. It is diffused by the part 13. That is, the linear light diffusing portion 12A, the linear light diffusing portion 12B, and the linear light diffusing portion 13 improve the emission efficiency from the first main plane 8 of the light incident on the light guide plate body 4 from the LEDs 3A and 3B.
  • the diffusion of light contributes to uniform brightness in the first main plane 8.
  • the light emitted from the LEDs 3A and 3B and entering the light guide plate main body 4 is transmitted through the light guide plate main body 4 and directly emitted from the first main plane 8 or reflected from the light guide plate main body 4 as described above. After exiting to the surface 5A side, it is reflected by the reflecting surface 5A, passes through the light guide plate body 4 again, and exits upward from the first main plane 8.
  • point light diffusion portions 10 ⁇ / b> A and 10 ⁇ / b> B and a point light diffusion portion 11 are formed on the first main plane 8.
  • Light emitted from the light guide plate body 4 through the point light diffusion portions 10A and 10B or the point light diffusion portions 11 is diffused and emitted by the point light diffusion portions 10A and 10B or the point light diffusion portions 11. The That is, by forming the point light diffusing portions 10A and 10B and the point light diffusing portion 11 on the first main plane 8, the luminance on the first main plane 8 is made uniform.
  • the light transmitted mainly through the linear light diffusion portion 12A is incident on the point light diffusion portion 10A, and is diffused and emitted. That is, the linear light diffusing unit 12A can make the luminance of the light emitted from the region including the point light diffusing unit 10A uniform. Further, the linear light diffusion portion 12A is emitted from the LED 3B, and the light that travels through the light guide plate body 4 and reaches the linear light diffusion portion 12A is diffused by the linear light diffusion portion 12A and emitted from the first main plane 8. . Therefore, the linear light diffusion portion 12A can also increase the emission efficiency in the linear light diffusion portion 12A of the first main plane 8.
  • the light transmitted mainly through the linear light diffusion portion 12B is incident on the point light diffusion portion 10B, and is diffused and emitted. That is, the linear light diffusing unit 12B makes it possible to make the luminance of light emitted from the region including the point light diffusing unit 10B uniform. Further, the linear light diffusion portion 12B is emitted from the LED 3A, and the light that travels through the light guide plate body 4 and reaches the linear light diffusion portion 12B is diffused by the linear light diffusion portion 12B and emitted from the first main plane 8. . Therefore, the linear light diffusion portion 12B can also increase the emission efficiency in the linear light diffusion portion 12B on the first main plane 8.
  • the point light diffusing unit 11 mainly transmits light transmitted through the linear light diffusing unit 13 or light emitted from the LEDs 3A and 3B, travels through the light guide plate body 4 and reaches the point light diffusing unit 11. However, it progresses and is diffused by the point light diffusion part 11 and is emitted from the first main plane 8. Therefore, the point light diffusing unit 11 that travels can increase the emission efficiency of the point light diffusing unit 11 on the first main plane 8.
  • the cross-sectional shapes of the grooves 12AA and 12BB and the grooves 13A forming the linear light diffusion portions 12A and 12B and the linear light diffusion portion 13 are substantially triangular.
  • the cross-sectional shape of the groove is not limited to a triangle as long as it has an inclined surface facing the end faces 6 and 7, and may be, for example, a substantially semicircular shape or a trapezoid.
  • the linear light diffusing portions 12A and 12B and the linear light diffusing portion 13 may be formed by ridges projecting downward, that is, toward the reflecting surface 5A, instead of being grooves.
  • the light guide plate 2 receives the light emitted from the plurality of LEDs 3A and the plurality of LEDs 3B, which are a plurality of light sources arranged in parallel, and the end surface 6 as the first end surface disposed opposite to each other and the first surface 6
  • An end face 7 as two end faces, a first main plane 8 and a second main plane 9 arranged opposite to each other, which emit light from the plurality of LEDs 3A and 3B incident from the end faces 6 and 7;
  • a reflecting plate 5 is disposed as opposed to the plane 9 and serves as reflecting means for reflecting the light emitted from the second main plane 9 to the second main plane 9 side.
  • the point light diffusion parts 10A and 10B and the linear light diffusion parts 12A and 12B are formed.
  • the first main plane 8 and the second main plane 9 the first main plane 8, which is one of the main planes, is formed with point light diffusion portions 10A, 10B, and the second main plane is the second main plane.
  • linear light diffusion portions 12A and 12B are formed.
  • the point light diffusing portions 10A and 10B are formed by a set of a large number of protrusions or holes.
  • the linear light diffusion portions 12A and 12B are formed by a set of a large number of ridges or grooves parallel to the parallel direction of the plurality of LEDs 3A and 3B whose length directions are parallel.
  • the light guide plate 2 By configuring the light guide plate 2 in this way, the light emitted from the LEDs 3A and 3B and entering the light guide plate main body 4 can improve the output efficiency of emitting from the first main plane 8,
  • the luminance distribution on the first main plane 8 can be made uniform.
  • luminance tends to become low in the area
  • the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B to the light guide plate body 4, the light emitted from the first main plane 8 where the luminance tends to be low is emitted.
  • the light quantity can be improved and the luminance distribution can be made uniform.
  • the formation density of a recessed part or a convex part becomes high, so that the point-like light-diffusion part 11 leaves
  • the total reflection on the first main plane 8 of the light traveling through the light guide plate body 4 is easily broken. Therefore, in the point light diffusion part 11, the emission efficiency of light traveling through the light guide plate body 4 is improved.
  • the intensity of light emitted from the LEDs 3A and 3B decreases as the distance from the optical axis of the LEDs 3A and 3B increases. Therefore, as the distance from the optical axis of each LED 3A and LED 3B increases, the distance from the optical axis of the LEDs 3A and 3B increases by increasing the formation density of the concave portions or the convex portions constituting the point light diffusing portion 11.
  • the light emission efficiency at the position can be improved, and the luminance of the light emission efficiency on the first main plane 8 can be made uniform.
  • punctate light-diffusion part 11 becomes high gradually as the distance from the optical axis of each LED3A and LED3B leaves
  • the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed in a range outside 70% of the irradiation angle of the LEDs 3A and 3B.
  • the light emission efficiency of light traveling in the light guide plate body 4 is increased. Therefore, if the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed on the optical axes of the LEDs 3A and 3B, the light emission efficiency in the originally high luminance portion is increased. The amount of light traveling to the low-luminance part away from the optical axis is reduced.
  • the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed in a range outside 70% of the irradiation angle of the LEDs 3A and 3B, and in a region close to the optical axis of the LEDs 3A and 3B.
  • the amount of emitted light By reducing the amount of emitted light, the amount of light traveling to a region far from the optical axis where the luminance tends to decrease can be increased.
  • the light guide plate 2 preferably has an interval between the end surface 6 and the end surface 7 of 30 mm or more and 80 mm or less.
  • the light guide plate body 4 and the reflection plate 5 are provided, and the end face 6 and the end face are formed by forming the point light diffusion portions 10A and 10B and the linear light diffusion portions 12A and 12B in the light guide plate body 4. Even if the distance to 7 is not less than 30 mm and not more than 80 mm, the light emission efficiency in the first main plane 8 can be improved and the luminance distribution can be made uniform. Furthermore, by forming the point light diffusing portion 11 and the linear light diffusing portion 13, it is possible to further improve the light emission efficiency and make the luminance distribution uniform in the first main plane 8.
  • the LEDs 3A and 3B for example, as shown in FIG. 5, a configuration in which the LED chip 20 is disposed in a cup-shaped reflecting plate 21 can be used.
  • the thickness of the light guide plate body 4, that is, the distance D between the first main plane 8 and the second main plane 9 is not less than the opening diameter R of the reflecting plate 21 and not more than three times the opening diameter R. preferable.
  • the thickness of the light guide plate body 4 is less than the opening diameter R, the amount of light emitted from the LEDs 3A and 3B cannot be incident on the end faces 6 and 7 and increases, which is not appropriate.
  • the thickness of the light guide plate body 4 increases, the light traveling from one end face (end face 6 or end face 7) to the other end face (end face 7 or end face 6) becomes the first main plane 8 and the second main plane 9. Reduces the number of reflections between and. Therefore, the number of times the light incident from the end faces 6 and 7 is diffused by the point light diffusion portions 10A and 10B, the linear light diffusion portions 12A and 12B, the point light diffusion portion 11 or the linear light diffusion portion 13 is reduced.
  • the thickness of the light guide plate body 4 not less than the opening diameter R and not more than three times the opening diameter R, the incident efficiency of the light emitted from the LEDs 3A and 3B to the end faces 6 and 7 can be increased. At the same time, the emission efficiency of the light emitted from the first main plane 8 and the luminance distribution can be made uniform efficiently.
  • the spot-like light diffusing portion 10 ⁇ / b> A is formed so that projections or holes are densely formed closer to the end face 6 side and become rougher as it is farther from the end face 6.
  • the spot-like light diffusing portion 10 ⁇ / b> B is formed so that projections or holes are densely formed closer to the end surface 7 side and become rougher as it is farther from the end surface 7.
  • the linear light diffusing portion 12 ⁇ / b> A is formed so that convex ridges or grooves are densely formed closer to the end surface 6 side and become rougher as the distance from the end surface 6 increases.
  • the linear light diffusing portion 12B is formed so that convex ridges or grooves are formed closer to the end face 7 side and become rougher as the distance from the end face 7 increases. By doing in this way, it is effective in the brightness fall in the darkening position between adjacent LED3A and LED3A and between adjacent LED3B and LED3B, and the edge part position on either side where LED3A and LED3B are not arrange
  • the brightness of the first main plane 8 that is the light exit surface of the light guide plate 2 can be made more uniform.
  • punctate light-diffusion parts 10A and 10B are comprised by many fine euros
  • punctate light-diffusion parts 10A and 10B are a fine several, for example You may form with a lens-shaped uneven part.
  • the concavo-convex shape of the point light diffusion portions 10A and 10B may be a structure in which a convex lens shape, a concave lens shape, or a conical concavo-convex portion is provided.
  • the portion corresponding to the light diffusion portion 12B is formed with a slope 6A and a slope 7A that are spaced apart from each other from the lower side (second main plane 9 side) to the upper side (first main plane 8 side). Is preferred.
  • the inclined surfaces 6A and 7A it is possible to improve the emission efficiency of emitting the light emitted from the LEDs 3A and 3B from the first main plane 8. That is, the light emitted from the LED 3A, incident on the light guide plate body 4 from the end face 6 and reaches the inclined surface 7A is reflected upward by the inclined surface 7A. Further, the light emitted from the LED 3B, incident on the light guide plate main body 4 from the end surface 7 and reaches the slope 6A is reflected upward by the slope 6A. Thereby, it is possible to improve the emission efficiency of emitting the light emitted from the LEDs 3A and 3B from the first main plane 8.
  • the light guide plate 2 may be configured to include a diffusion plate 30 and a light shielding plate 31 as a light shielding member above the first main plane 8.
  • the diffusion plate 30 includes a light incident surface 32 on which light emitted from the first main plane 8 is incident on the light guide plate body 4 side of the light guide plate 2, and a light emission surface from which light incident from the light incident surface 32 is emitted. 33.
  • protruding line portions 34 are formed on the front and rear sides of the diffuser plate 30, protruding line portions 34 are formed. The ridge 34 protrudes toward the light guide plate main body 4 and has a peripheral edge 8A (see FIGS.
  • a peripheral light incident surface 35 which is a light incident surface on which light emitted from the peripheral portions 8A and 8B is incident, is formed.
  • a gap 36 is formed between the front and rear ridges 34 of the diffusion plate 30.
  • the light incident surface 32 that is the bottom surface of the recess 36 is formed as a light incident surface on which light emitted from the first main plane 8 is incident.
  • the diffusion plate 30 for example, light scattering particles are mixed with a transparent material such as acrylic resin, polycarbonate resin, or glass, so that light incident on the diffusion plate 30 can be scattered and emitted to the outside. Yes.
  • the light scattering particles for example, the light scattering particles disclosed in JP2010-97088A, JP2010-123309A, and the like can be used.
  • the diffuser plate 30 has a light scattering surface on which an uneven surface is formed by a collection of a large number of holes or protrusions by performing a roughening treatment on the surface of the diffuser plate 30 instead of mixing light scattering particles. It is good also as a structure to have.
  • the diffuser plate 30 is rectangular in plan view, and the outer peripheral side surfaces (front, rear, left and right side surfaces) of the diffuser plate 30 are the same as the outer peripheral side surfaces (end surface 6, end surface 7, and left and right side surfaces) of the light guide plate body 4. It is arranged inside or protrudes outside it. 7 and 8, in the front-rear direction, the ridge outer surface 37 protrudes outward from the end surface 6 and the end surface 7 of the light guide plate body 4, and the left and right side surfaces of the light guide plate body 4 in the left-right direction. Are arranged in the same plane.
  • the outer peripheral side surface of the diffusing plate 30 is arranged in the same plane as the outer peripheral side surface of the light guide plate main body 4 or protrudes outward from the outer peripheral side surface. It is prescribed.
  • the ridges 34 are formed only on the front and rear sides of the peripheral edge of the diffusion plate 30, but may also be formed on the left and right sides of the diffusion plate 30. . By forming the ridges 34 over the entire periphery of the diffusion plate 30, the rigidity of the diffusion plate 30 can be increased.
  • the convex portion outer side surface 37 which is the outer side surface of the convex portion 34 is a surface in contact with air.
  • the ridge inner side surface 38 which is the inner side surface of the ridge 34 is also a surface in contact with air. Accordingly, a part of the light incident from the peripheral light incident surface 35 into the protruding portion 34 is totally reflected by the protruding portion outer surface 37 and the protruding portion inner side surface 38 and can be emitted from the light emitting surface 33.
  • the ridge outer surface 37 and the ridge inner surface 38 are parallel to each other, and the peripheral light incident surface 35 is a surface orthogonal to the ridge outer surface 37 and the ridge inner surface 38.
  • the peripheral light incident surface 35 of the ridge 34 is not shielded by the light shielding plate 31 and the light shielding region B, which is a region where the light emitted from the LEDs 3A, 3B or the peripheral portions 8A, 8B is shielded by the light shielding plate 31.
  • an incident region C that is an incident region. That is, by arranging the light shielding plate 31 between the peripheral light incident surface 35 of the ridge 34 and the peripheral portions 8A and 8B, the light emitted from the peripheral portions 8A and 8B enters the peripheral light incident surface 35. The amount of light can be limited.
  • the light shielding region B has at least a width (front and rear width dimensions) that does not allow the light emitted from the LEDs 3A and 3B to directly enter the diffusion plate 30 without passing through the light guide plate 2.
  • the width of the light-shielding region B (width dimension in the front-rear direction) and the width of the incident region C (width dimension in the front-rear direction) are determined from the peripheral portions 8A and 8B (see FIGS. 1 and 3) to the peripheral light incident surface 35.
  • the entire brightness of the light exit surface 33 is set to be uniform.
  • the light incident on the peripheral light incident surface 35 from the peripheral portions 8A and 8B is mainly emitted from the peripheral portion of the light emitting surface 33.
  • the width of the light shielding region B and the width of the incident region C are set so that the brightness of the peripheral portion of the light emitting surface 33 approaches the brightness inside the peripheral portion.
  • the light emitted from the first main plane 8 is incident on the light incident surface 32 and the peripheral light incident surface 35 of the diffusion plate 30, travels through the diffusion plate 30, and is emitted from the light emission surface 33.
  • the diffusion plate 30 contains light scattering particles. Therefore, the light incident on the diffusion plate 30 is scattered in the diffusion plate 30, and the luminance distribution of the light emitted from the light exit surface 33 can be made uniform.
  • the light emitted from the LEDs 3A and 3B is bright at a position close to the LEDs 3A and 3B, and becomes darker as the distance increases.
  • the LED 3A is provided on the end surface 6 of the light guide plate body 4
  • the LED 3B is provided on the end surface 7 of the light guide plate body 4, and the light travels forward and backward. By complementing each other, the luminance of the first main plane 8 of the light guide plate 2 is made uniform.
  • a light shielding plate 31 is disposed on the peripheral portions 8A and 8B of the light guide plate 2 near the LEDs 3A and 3B.
  • the light shielding plate 31 restricts light that is incident directly on the LEDs 3A and 3B or from the peripheral edge portions 8A and 8B to the ridges 34, and a part of the peripheral light incident surface 35 is a light shielding region B. That is, part of the light emitted from the LEDs 3 ⁇ / b> A and 3 ⁇ / b> B toward the peripheral light incident surface 35 is shielded by the light shielding region B, that is, the light shielding plate 31.
  • the incident region C a part of the light emitted from the first main plane 8 toward the peripheral light incident surface 35 of the ridge 34 is incident.
  • a part of the light incident from the peripheral light incident surface 35 of the ridge portion 34 is totally reflected by the ridge portion inner side surface 38 and the ridge portion outer surface 37 of the ridge portion 34, and is also a light scattering particle.
  • the light travels while being scattered, and is emitted mainly from the light exit surface 33 of the diffuser plate 30 above the region where the protrusions 34 are disposed, that is, from the peripheral portion of the light exit surface 33 on the side where the LEDs 3A and 3B are disposed.
  • a part of the light incident in the ridge 34 is totally reflected on the ridge outer surface 37 and the ridge inner surface 38 and is scattered while being scattered by the light scattering particles.
  • the light is emitted from the emission surface 33 in a diffuse state.
  • the light incident on the ridge 34 is emitted mainly from above the position where the ridge 34 is disposed.
  • the light shielding region B is formed by the light shielding plate 31. This prevents the light emitted from the LEDs 3A and 3B from directly entering the diffusion plate 30. Further, part of the light incident on the light guide plate 2 is guided while being scattered by the light scattering particles in the light guide plate 2, emitted as diffused light from the first main plane 8, and incident on the diffuser plate 30. . The light emitted from the first main plane 8 passes through the diffusion plate 30 and is emitted from the light emission surface 33 in a state of being further diffused by the diffusion plate 30. Furthermore, the illuminating device 1 has a ridge 34 formed on the peripheral edge of the diffusion plate 30 on the side where the LEDs 3A and 3B are arranged.
  • the protruding line part 34 By providing the protruding line part 34, the protruding line part outer surface 37 and the protruding line part inner side surface 38 are formed. Therefore, part of the light emitted from the peripheral portions 8A and 8B of the light guide plate 2 and incident on the peripheral light incident surface 35 of the convex portion 34 is a convex portion outer side surface 37 and a convex portion inner side surface 38 of the convex portion 34. And diffused light is emitted from the peripheral edge of the light emitting surface 33 of the diffusion plate 30 while being totally reflected by the light scattering particles and scattered by the light scattering particles.
  • the light shielding region B with the light shielding plate 31, the light emitted from the LEDs 3 ⁇ / b> A and 3 ⁇ / b> B can be incident on the light guide plate 2 without being directly incident on the diffusion plate 30.
  • a part of the light incident on the light guide plate 2 is guided while being scattered by the light scattering particles in the light guide plate 2, exits from the first main plane 8 as diffused light, and enters the diffuser plate 30.
  • the emitted light of LED3A, 3B injects into the diffuser plate 30 directly, it can prevent that the part of LED3A, 3B looks like a point light source.
  • the ridge 34 is provided on the diffusion plate 30, the light emitted from the peripheral portions 8 ⁇ / b> A and 8 ⁇ / b> B is guided into the ridge 34 from the peripheral light incident surface 35 of the ridge 34, and The light is scattered by the light scattering particles while being totally reflected by the inner surface 38 and the outer surface 37 of the protruding portion of the portion 34, and is emitted as diffused light from the peripheral portion of the light emitting surface 33 of the diffusion plate 30.
  • the light shielding plate 31 even when the light shielding plate 31 is provided, it is possible to prevent a dark portion that is shielded by the light shielding plate 31 from the edge of the light emitting surface 33 on the side where the light shielding plate 31 is provided.
  • the lighting device 1 does not darken the peripheral portion of the light emitting surface 33 as if the peripheral portion of the light emitting surface 33 is edged while eliminating the appearance that the LEDs 3A and 3B appear as point light sources.
  • the overall brightness of the emission surface 33 can be made uniform.
  • the size of the light incident area C of the ridge 34 can be adjusted by increasing or decreasing the width of the ridge 34. That is, the brightness of the central portion and the peripheral portion of the light exit surface of the diffuser plate 30 can be easily made uniform by adjusting the amount of light emitted from the light guide plate 2 to the ridges 34. it can.
  • the light shielding region B is formed by, for example, attaching a light shielding tape to the peripheral light incident surface 35 or applying a light shielding coating. Can do.
  • the light shielding plate 31 may not be provided between the light guide plate 2 and the peripheral light incident surface 35. Even in such a configuration, the light that has entered the ridge 34 from the peripheral light incident surface 35 enters the ridge 34. The light is emitted from the light emitting surface 33 in a diffused state while being totally reflected by the protruding portion outer surface 37 and the protruding portion inner side surface 38 and being scattered by the light scattering particles. Therefore, a decrease in luminance is suppressed at the periphery of the light emitting surface 33, and the overall brightness of the light emitting surface 33 can be made uniform.
  • the light guide plate main body 4 is formed by forming the point light diffusing portions 10A and 10B and the point light diffusing portion 11 on the second main plane 9 facing the reflecting surface 5A, and the linear light diffusing portion 12A. , 12B and the linear light diffusion portion 13 may be formed on the first main plane 8 serving as a light emission surface.
  • the large-sized panel type illuminating device 100 can be comprised by paralleling the illuminating device 1 provided with the diffusion plate 30 shown in the above-mentioned 3rd Embodiment in parallel.
  • FIG. 10 is a plan view showing an example of a panel-type lighting device 100 in which two lighting devices 1 are arranged in parallel. As shown in FIG. 10, in the panel illumination device 100, each illumination device 1 is arranged such that the protruding portion outer surfaces 37 of the illumination devices 1 are in close contact with each other.
  • the illumination device 1 is not dark as if the peripheral portion of the light emitting surface 33 is trimmed, and the luminance is uniform including the peripheral portion. Therefore, even when the two lighting devices 1 are juxtaposed, the large-sized panel type lighting device 100 having a good appearance can be realized without the joint portion being trimmed.
  • the arrangement of the illumination devices 1 is not limited.
  • the number of the lighting devices 1 may be three or more, and the direction of the arrangement is not particularly limited.

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  • General Physics & Mathematics (AREA)
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  • General Engineering & Computer Science (AREA)
  • Planar Illumination Modules (AREA)

Abstract

Provided is a light guide plate capable of emitting light that was emitted from a light source and incident thereto while achieving uniform luminance and improved emission efficiency of an emission surface. Also provided is a lighting device. This light guide plate comprises: an end surface (6) and an end surface (7) which are disposed facing each other and to which light respectively emitted from a plurality of LEDs (3A, 3B) arranged in rows is incident; a first main flat surface (8) and a second main flat surface (9) which are disposed facing each other and from which the light incident from the respective end surfaces (6, 7) is emitted; and a reflection means (5) which is disposed facing the second main flat surface (9). In the respective main flat surfaces (8, 9), dotted light diffusion portions (10A, 10B) and linear light diffusion portions (12A, 12B), said portions having widths that decrease from the respective end surfaces (6, 7) toward the end surface opposite thereto, are formed in regions corresponding to spaces between adjacent light sources of the plurality of LEDs (3A, 3B) arranged in rows.

Description

導光板、照明装置Light guide plate, lighting device
　本発明は、導光板および照明装置に関する。 The present invention relates to a light guide plate and a lighting device.
　従来、特許文献１から３に開示されるように、ＬＥＤ（Ｌｉｇｈｔ Ｅｍｉｔｔｉｎｇ Ｄｉｏｄｅ）光源から出射された光を出射面から面光源として出射させる導光板が知られている。かかる導光板においては、ＬＥＤから出射され入射した光を出射する出射面における輝度の均一化と出射効率の向上を図ることが要求されている。 Conventionally, as disclosed in Patent Documents 1 to 3, there is known a light guide plate that emits light emitted from an LED (Light Emitting Diode) light source as a surface light source from an emission surface. In such a light guide plate, it is required to make the luminance uniform and improve the emission efficiency on the emission surface that emits the light emitted from the LED.
特開２０１０－２１８６９３号公報JP 2010-218693 A 特開平９－１０１５２１号公報JP-A-9-101521 特開平９－６１６３１号公報JP-A-9-61631
　そこで、本発明は、光源から出射され入射した光を出射面における輝度の均一化と出射効率の向上を図って出射することができる導光板および照明装置を提供することを目的とする。 Accordingly, an object of the present invention is to provide a light guide plate and an illumination device that can emit light emitted from a light source and emitting light with uniform brightness on the emission surface and improvement of emission efficiency.
　上記課題を解決するために、本発明の導光板は、並列される複数の光源から出射される光が入射し、互いに対向して配置される第１端面および第２端面と、各端面から入射した複数の光源からの光が出射する互いに対向して配置される第１主平面および第２主平面と、第２主平面に対向して配置され、第２主平面から出射された光を第２主平面側に反射する反射手段とを有し、各主平面には、並列される複数の光源の隣り合う光源の間に対応した領域に、各端面から対向する端面に向かうに従って幅が狭くなる第１光拡散部が形成され、各主平面のうち、いずれか一方の主平面に形成される第１光拡散部は、多数の突起または穴の集合にて形成される点状第１光拡散部であり、他方の主平面に形成される第１光拡散部は、長さ方向が複数の光源の並列方向に平行な多数の凸条または溝の集合にて形成される線状第１光拡散部であることとする。 In order to solve the above-described problems, the light guide plate of the present invention receives light emitted from a plurality of light sources arranged in parallel, and is incident from the first end surface and the second end surface arranged to face each other, and from each end surface. The first main plane and the second main plane arranged opposite to each other from which the light from the plurality of light sources emits, and the light emitted from the second main plane arranged in the first main plane are opposed to the second main plane. 2 reflecting means for reflecting on the main plane side, and in each main plane, the width becomes narrower from each end face toward the opposite end face in a region corresponding to between adjacent light sources of a plurality of light sources arranged in parallel. The first light diffusing portion is formed, and the first light diffusing portion formed on any one of the main planes is a point-like first light formed by a set of many protrusions or holes. The first light diffusing portion that is the diffusing portion and is formed on the other main plane has a plurality of length directions. And it is linear first light diffusing portion formed at a collection of a large number of ridges or grooves parallel to the array direction of the source.
　また、上記発明に加えて、導光板は、点状第１光拡散部は、第２主平面に形成され、線状第１光拡散部は、第１主平面に形成されていることとする。 In addition to the above invention, in the light guide plate, the dotted first light diffusing portion is formed on the second main plane, and the linear first light diffusing portion is formed on the first main plane. .
　また、上記発明に加えて、導光板は、点状第１光拡散部および線状第１光拡散部は、光源の照射角の７０％よりも外側の範囲に形成されていることとする。 In addition to the above invention, in the light guide plate, the dotted first light diffusing portion and the linear first light diffusing portion are formed in a range outside 70% of the irradiation angle of the light source.
　また、上記発明に加えて、導光板は、各主平面には、第１端面側に形成される第１光拡散部と第２端面側に形成される第１光拡散部との間に第２光拡散部が形成され、第１拡散部として点状第１光拡散部が形成される側の主平面に形成される第２光拡散部は、多数の突起または穴の集合にて形成される点状第２光拡散部であり、第１拡散部として線状第１光拡散部が形成される側の主平面に形成される第２光拡散部は、長さ方向が光源の並列方向に平行な多数の凸条または溝の集合にて形成される線状第２光拡散部であることとする。 Further, in addition to the above invention, the light guide plate may be provided on each main plane between the first light diffusion portion formed on the first end surface side and the first light diffusion portion formed on the second end surface side. The second light diffusing portion formed on the main plane on the side where the two light diffusing portions are formed and the point-like first light diffusing portion is formed as the first diffusing portion is formed by a set of many protrusions or holes. The second light diffusing portion formed on the main plane on the side where the linear first light diffusing portion is formed as the first diffusing portion has a length direction parallel to the light source. It is assumed that the linear second light diffusing portion is formed by a set of a large number of ridges or grooves parallel to each other.
　また、上記発明に加えて、導光板は、点状第２光拡散部は、光源の照明光軸からの距離が遠いほど形成密度が高いこととする。 Further, in addition to the above invention, in the light guide plate, it is assumed that the dotted second light diffusion portion has a higher formation density as the distance from the illumination optical axis of the light source is longer.
　また、上記発明に加えて、導光板は、第１端面と第２端面との間隔が３０ｍｍ以上８０ｍｍ以下であることとする。 Further, in addition to the above invention, the light guide plate has a distance between the first end surface and the second end surface of 30 mm or more and 80 mm or less.
　また、上記発明に加えて、導光板は、光源が、ＬＥＤチップをカップ状の反射板内に配置したＬＥＤであり、導光板の第１主平面と第２主平面との間隔は、反射板の開口径以上であり開口径の３倍以下であることとする。 In addition to the above invention, the light guide plate is an LED in which the light source is an LED chip disposed in a cup-shaped reflection plate, and the distance between the first main plane and the second main plane of the light guide plate is the reflection plate. It is assumed that the opening diameter is not less than three times the opening diameter.
　また、上記発明に加えて、導光板は、第１端面と第２端面とは、領域に対応した部分が第２主平面から第１主平面に向かって互いに間隔が広くなる斜面に形成されていることとする。 Further, in addition to the above invention, the light guide plate is formed such that the first end surface and the second end surface are inclined surfaces in which portions corresponding to the regions are spaced apart from each other from the second main plane toward the first main plane. Suppose that
　また、上記発明に加えて、導光板は、第１主平面から出射した光が入射する光入射面と、この光入射面から入射した光が出射する光出射面とを有する拡散板が第１主平面の側に配置され、拡散板は、第１主平面側に突出し、導光板の第１主平面の周縁部のうち少なくとも各端面側の周縁部に対向する位置に設けられ、各周縁部から出射する光が入射する光入射面である周縁光入射面を有する凸条部を有することとする。 In addition to the above invention, the light guide plate includes a light diffusing plate having a light incident surface on which light emitted from the first main plane is incident and a light emitting surface from which light incident from the light incident surface is emitted. The diffuser plate is disposed on the main plane side, and the diffusion plate protrudes toward the first main plane side, and is provided at a position facing at least the peripheral portion on each end face side of the peripheral portion of the first main plane of the light guide plate. It has a ridge part which has a peripheral light incident surface which is a light incident surface in which the light radiate | emitted from enters.
　また、上記発明に加えて、導光板は、各周縁部と凸条部の周縁光入射面との間には、周縁部から出射した光が周縁光入射面に入射する光量を制限する光遮蔽部が備えられていることとする。 In addition to the above invention, the light guide plate is a light shield that restricts the amount of light emitted from the peripheral portion from entering the peripheral light incident surface between each peripheral portion and the peripheral light incident surface of the ridge. Parts are provided.
　上記課題を解決するために、本発明の照明装置は、上述の導光板と、この導光板の端面に光を入射する光源とを有することとする。 In order to solve the above-described problems, the illumination device of the present invention includes the above-described light guide plate and a light source that makes light incident on an end surface of the light guide plate.
本発明の第１の実施の形態に係る照明装置の構成を示す斜視図である。上段（Ａ）は、照明装置を右後方から見た斜視図であり、下段（Ｂ）は、照明装置を右前方から見た斜視図である。It is a perspective view which shows the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The upper part (A) is a perspective view of the lighting device as viewed from the right rear, and the lower part (B) is a perspective view of the lighting device as viewed from the right front. 図１（Ａ）（Ｂ）に示す切断線Ａ－Ａにおける照明装置の断面の構造を示す断面図である。FIG. 2 is a cross-sectional view illustrating a cross-sectional structure of the lighting device taken along a cutting line AA illustrated in FIGS. 照明装置を光出射面側から見た平面図である。It is the top view which looked at the illuminating device from the light-projection surface side. 反射板を取り除いた状態の照明装置を、下方から見た斜視図である。It is the perspective view which looked at the illuminating device of the state which removed the reflecting plate from the downward direction. ＬＥＤの反射板の開口径と導光板本体の厚さとの関係を説明する図である。It is a figure explaining the relationship between the opening diameter of the reflecting plate of LED, and the thickness of a light-guide plate main body. 本発明の第２の実施の形態に係る照明装置の構成を示す斜視図である。上段（Ａ）は、照明装置を右後方から見た斜視図であり、下段（Ｂ）は、照明装置を右前方から見た斜視図である。It is a perspective view which shows the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The upper part (A) is a perspective view of the lighting device as viewed from the right rear, and the lower part (B) is a perspective view of the lighting device as viewed from the right front. 本発明の第３の実施の形態に係る照明装置の構成を示す斜視図である。It is a perspective view which shows the structure of the illuminating device which concerns on the 3rd Embodiment of this invention. 図７に示す切断線Ｄ－Ｄにおける照明装置の断面の構造を示す断面図である。なお、構成を判り易くするため、ハッチングを省略している。FIG. 8 is a cross-sectional view showing a cross-sectional structure of the illumination device taken along a cutting line DD shown in FIG. 7. Note that hatching is omitted for easy understanding of the configuration. 本発明の第４の実施の形態に係る照明装置の構成を示す断面図である。なお、構成を判り易くするため、ハッチングを省略している。It is sectional drawing which shows the structure of the illuminating device which concerns on the 4th Embodiment of this invention. Note that hatching is omitted for easy understanding of the configuration. 本発明の照明装置を２個並列させたパネル型照明装置の１例を示す平面図である。It is a top view which shows an example of the panel type illuminating device which arranged two illuminating devices of this invention in parallel.
　以下、本発明の実施の形態に係る照明装置１および導光板２について、図面を参照しながら説明する。なお、導光板２は、照明装置１の構成に併せて説明する。 Hereinafter, the illumination device 1 and the light guide plate 2 according to embodiments of the present invention will be described with reference to the drawings. The light guide plate 2 will be described together with the configuration of the lighting device 1.
（第１の実施の形態）
　図１は、本発明の第１の実施の形態に係る照明装置１の構成を示す斜視図であり、上段（Ａ）は、照明装置１を右後方から見た斜視図であり、下段（Ｂ）は、照明装置１を右前方から見た斜視図である。図２は、図１（Ａ）（Ｂ）に示す切断線Ａ－Ａにおける照明装置１の断面の構造を示す断面図である。図２においては、構成を判り易くするため、ハッチングが省略されている。図３は、照明装置１を光出射面側から見た平面図である。図４は、反射板５を取り除いた状態の照明装置１を、下方から見た斜視図である。なお、以下の各実施の形態の説明において、導光板２の光の導光方向を前後方向とし、矢視Ｘ１方向を前方（前側）、矢視Ｘ２方向を後方（後側）として説明する。また、ＬＥＤ３ＡおよびＬＥＤ３Ｂの並列方向を左右方向とし、矢視Ｙ１方向を左方（左側）、矢視Ｙ２方向を右方（右側）として説明する。そして、照明装置１の光の出射方向を上方向とし、矢視Ｚ１方向を上方（上側）、矢視Ｚ２方向を下方（下側）として説明する。 (First embodiment)
FIG. 1 is a perspective view showing a configuration of a lighting device 1 according to the first embodiment of the present invention, and an upper stage (A) is a perspective view of the lighting apparatus 1 viewed from the right rear side, and a lower stage (B ) Is a perspective view of the illumination device 1 as viewed from the right front. FIG. 2 is a cross-sectional view showing a cross-sectional structure of the lighting device 1 taken along the cutting line AA shown in FIGS. In FIG. 2, hatching is omitted for easy understanding of the configuration. FIG. 3 is a plan view of the illumination device 1 as seen from the light exit surface side. FIG. 4 is a perspective view of the lighting device 1 with the reflection plate 5 removed, as viewed from below. In the following description of each embodiment, the light guide direction of the light guide plate 2 is the front-rear direction, the arrow X1 direction is the front (front side), and the arrow X2 direction is the rear (rear side). The parallel direction of LED 3A and LED 3B will be described as the left-right direction, the arrow Y1 direction will be left (left side), and the arrow Y2 direction will be right (right side). And the light emission direction of the illuminating device 1 is set as an upward direction, the arrow Z1 direction is upward (upper side), and the arrow Z2 direction is downward (lower side).
（照明装置１）
　図１（Ａ）（Ｂ）および図２に示すように、照明装置１は、導光板２と、光源としてのＬＥＤ３Ａ，３Ｂとを有する。導光板２は、導光板本体４と、反射手段を構成する反射板５とを有し、反射板５の上方に導光板本体４が配置されている。導光板本体４の後側の端面６には、複数のＬＥＤ３Ａが備えられている。ＬＥＤ３Ａは、左右方向に並列されている。また、導光板本体４の前側の端面７には、複数のＬＥＤ３Ｂが備えられ、ＬＥＤ３ＢもＬＥＤ３Ａと同様に、左右方向に並列されている。すなわち、導光板本体４に対して配置されるＬＥＤ３ＡおよびＬＥＤ３Ｂとは、導光板本体４を前後方向に挟んで反対側に配置されている。 (Lighting device 1)
As shown in FIGS. 1A and 1B and FIG. 2, the lighting device 1 includes a light guide plate 2 and LEDs 3A and 3B as light sources. The light guide plate 2 includes a light guide plate main body 4 and a reflection plate 5 that constitutes a reflection means, and the light guide plate main body 4 is disposed above the reflection plate 5. A plurality of LEDs 3 </ b> A are provided on the end face 6 on the rear side of the light guide plate body 4. The LEDs 3A are arranged in parallel in the left-right direction. The front end face 7 of the light guide plate body 4 is provided with a plurality of LEDs 3B, and the LEDs 3B are also juxtaposed in the left-right direction, like the LEDs 3A. That is, the LED 3A and the LED 3B disposed with respect to the light guide plate body 4 are disposed on the opposite side with the light guide plate body 4 sandwiched in the front-rear direction.
　なお、ＬＥＤ３Ａ，３Ｂに代えて、ＣＣＦＬ（Ｃｏｌｄ Ｃａｔｈｏｄｅ Ｆｌｕｏｒｅｓｃｅｎｔ Ｌａｍｐ：冷陰極蛍光管）、電球（たとえば白熱電球）や蛍光灯などを光源として用いてもよい。ＬＥＤは、他の光源と比べ、消費電力および発熱量が小さく、また、小型化しやすい点等で優れている。したがって、光源としては、ＬＥＤを用いることが好ましい。 In place of the LEDs 3A and 3B, a CCFL (Cold Cathode Fluorescent Lamp), a light bulb (for example, an incandescent light bulb), a fluorescent light, or the like may be used as a light source. LEDs are superior to other light sources in that they consume less power and generate more heat, and are easier to miniaturize. Therefore, it is preferable to use an LED as the light source.
（導光板本体４）
　導光板本体４は、たとえば、透明なアクリル樹脂から形成される充実構造である。導光板本体４は、平面視において矩形であり、全体として上下方向に扁平した板状体を呈し、ＬＥＤ３Ａが配置される端面６と、ＬＥＤ３Ｂが配置される端面７と、第１主平面８と、第２主平面９とを有する。 (Light guide plate body 4)
The light guide plate body 4 has a solid structure formed of, for example, a transparent acrylic resin. The light guide plate main body 4 has a rectangular shape in plan view, presents a plate-like body flattened in the vertical direction as a whole, an end surface 6 on which the LEDs 3A are disposed, an end surface 7 on which the LEDs 3B are disposed, and a first main plane 8 And a second main plane 9.
　導光板本体４の第１主平面８の周縁部のうち、端面６側の周縁部８Ａには、点状第１光拡散部としての点状光拡散部１０Ａが形成されている。点状光拡散部１０Ａは、導光板本体４に対して備えられる複数のＬＥＤ３Ａ（図１（Ａ）参照）の隣接するＬＥＤ３Ａ同士の間に対応する位置に形成されている。点状光拡散部１０Ａは、周縁部８Ａの左右の端縁にも形成されている。点状光拡散部１０Ａは、後方から前方に向かうに従って左右方向の幅が狭くなる形状を呈している。すなわち、点状光拡散部１０Ａは、端面６側を底辺とする三角形を呈している。 Of the peripheral portion of the first main plane 8 of the light guide plate main body 4, a dotted light diffusion portion 10A as a dotted first light diffusion portion is formed in the peripheral portion 8A on the end face 6 side. The dotted light diffusing portion 10A is formed at a position corresponding to between adjacent LEDs 3A of a plurality of LEDs 3A (see FIG. 1A) provided for the light guide plate body 4. The dotted light diffusion portion 10A is also formed on the left and right edges of the peripheral portion 8A. The dotted light diffusing portion 10A has a shape in which the width in the left-right direction becomes narrower from the rear toward the front. That is, the point light diffuser 10A has a triangular shape with the end face 6 side as a base.
　また、導光板本体４の第１主平面８の周縁部のうち、端面７側の周縁部８Ｂには、点状第１光拡散部としての点状光拡散部１０Ｂが形成されている。点状光拡散部１０Ｂは、導光板本体４に対して備えられる複数のＬＥＤ３Ｂ（図１（Ｂ）参照）の隣接するＬＥＤ３Ｂ同士の間に対応する位置に形成されている。点状光拡散部１０Ｂは、周縁部８Ｂの左右の端縁にも形成されている。点状光拡散部１０Ｂは、前方から後方に向かうに従って左右方向の幅が狭くなる形状を呈している。すなわち、点状光拡散部１０Ｂは、端面７側を底辺とする三角形を呈している。 Further, among the peripheral portions of the first main plane 8 of the light guide plate body 4, a dotted light diffusion portion 10 </ b> B as a dotted first light diffusion portion is formed on the peripheral portion 8 </ b> B on the end surface 7 side. The dotted light diffusing portion 10B is formed at a position corresponding to between adjacent LEDs 3B of a plurality of LEDs 3B (see FIG. 1B) provided for the light guide plate body 4. The point light diffusion part 10B is also formed on the left and right edges of the peripheral edge part 8B. The dotted light diffusion portion 10B has a shape in which the width in the left-right direction becomes narrower from the front to the rear. That is, the dotted light diffusion portion 10B has a triangular shape with the end face 7 side as a base.
　導光板本体４の第１主平面８には、点状光拡散部１０Ａと点状光拡散部１０Ｂとの間に点状第２光拡散部としての点状光拡散部１１が形成されている。点状光拡散部１１は、前後方向で互いに対向して配置される点状光拡散部１０Ａと点状光拡散部１０Ｂとのそれぞれの間に形成されている。 On the first main plane 8 of the light guide plate body 4, a point light diffusion portion 11 as a point second light diffusion portion is formed between the point light diffusion portion 10 </ b> A and the point light diffusion portion 10 </ b> B. . The dotted light diffusing portion 11 is formed between the dotted light diffusing portion 10A and the dotted light diffusing portion 10B, which are arranged to face each other in the front-rear direction.
　点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１は、第１主平面８の点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１に対応する位置に粗面化処理を施すことにより形成される凹凸面である。粗面化処理により、点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１は、たとえば、多数の孔の集合にて凹凸面が形成される。点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１は、多数の突起の集合にて凹凸面を形成してもよい。 The spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 perform a roughening process at positions corresponding to the spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 on the first main plane 8. It is the uneven surface formed by. By the roughening treatment, the spot-like light diffusing parts 10A, 10B and the spot-like light diffusing part 11 have, for example, a concavo-convex surface formed by a set of many holes. The spot-like light diffusing parts 10A and 10B and the spot-like light diffusing part 11 may form a concavo-convex surface with a set of many protrusions.
　図２，４に示すように、導光板本体４の第２主平面９の周縁部のうち、端面６側の周縁部９Ａには、線状第１光拡散部としての線状光拡散部１２Ａが形成されている。線状光拡散部１２Ａは、導光板本体４に対して備えられる複数のＬＥＤ３Ａ（図１（Ａ）参照）の隣接するＬＥＤ３Ａ同士の間に対応する位置に形成されている。線状光拡散部１２Ａは、周縁部９Ａの左右の端縁にも形成されている。線状光拡散部１２Ａは、後方から前方に向かうに従って左右方向の幅が狭くなる形状を呈している。すなわち、線状光拡散部１２Ａは、端面６側を底辺とする三角形を呈している。 As shown in FIGS. 2 and 4, among the peripheral portions of the second main plane 9 of the light guide plate body 4, a linear light diffusion portion 12 </ b> A as a linear first light diffusion portion is provided on the peripheral portion 9 </ b> A on the end surface 6 side. Is formed. The linear light diffusion portion 12A is formed at a position corresponding to between adjacent LEDs 3A of a plurality of LEDs 3A (see FIG. 1A) provided for the light guide plate body 4. The linear light diffusion portion 12A is also formed on the left and right edges of the peripheral portion 9A. The linear light diffusion portion 12A has a shape in which the width in the left-right direction becomes narrower from the rear toward the front. That is, the linear light diffusion portion 12A has a triangular shape with the end face 6 side as a base.
　また、導光板本体４の第２主平面９の周縁部のうち、端面７側の周縁部９Ｂには、線状第１光拡散部としての線状光拡散部１２Ｂが形成されている。線状光拡散部１２Ｂは、導光板本体４に対して備えられる複数のＬＥＤ３Ｂ（図１（Ｂ）参照）の隣接するＬＥＤ３Ｂ同士の間に対応する位置に形成されている。線状光拡散部１２Ｂは、周縁部９Ｂの左右の端縁にも形成されている。線状光拡散部１２Ｂは、前方から後方に向かうに従って左右方向の幅が狭くなる形状を呈している。すなわち、線状光拡散部１２Ｂは、端面７側を底辺とする三角形を呈している。 Further, among the peripheral portions of the second main plane 9 of the light guide plate body 4, a linear light diffusion portion 12B as a linear first light diffusion portion is formed in the peripheral portion 9B on the end face 7 side. The linear light diffusion portion 12B is formed at a position corresponding to between adjacent LEDs 3B of a plurality of LEDs 3B (see FIG. 1B) provided for the light guide plate body 4. The linear light diffusion portion 12B is also formed on the left and right edges of the peripheral portion 9B. The linear light diffusion portion 12B has a shape in which the width in the left-right direction becomes narrower from the front toward the rear. That is, the linear light diffusing portion 12B has a triangular shape with the end face 7 side as a base.
　線状光拡散部１２Ａ，１２Ｂは、第２主平面９に形成される複数の溝１２ＡＡ，１２ＢＢにて形成することができる。溝１２ＡＡ，１２ＢＢは、長手方向が複数のＬＥＤ３Ａ，３Ｂの並列方向に平行な溝である。すなわち、溝１２ＡＡ，１２ＢＢは、端面６，端面７に平行であり、長手方向が左右方向に形成される溝である。 The linear light diffusion portions 12A and 12B can be formed by a plurality of grooves 12AA and 12BB formed in the second main plane 9. The grooves 12AA and 12BB are grooves whose longitudinal direction is parallel to the parallel direction of the plurality of LEDs 3A and 3B. That is, the grooves 12AA and 12BB are grooves that are parallel to the end faces 6 and 7 and whose longitudinal direction is formed in the left-right direction.
　また、導光板本体４の第２主平面９には、線状光拡散部１２Ａと線状光拡散部１２Ｂとの間に線状第２光拡散部としての線状光拡散部１３（図２，４参照）が形成されている。線状光拡散部１３は、第２主平面９に形成される複数の溝１３Ａにて形成することができる。溝１３Ａは、長手方向が複数のＬＥＤ３Ａ，３Ｂの並列方向に平行な溝である。すなわち、溝１３Ａは、端面６，端面７に平行であり、第２主平面９の左右方向の一端縁から他端縁に亘って形成される。 Further, on the second main plane 9 of the light guide plate body 4, a linear light diffusion portion 13 (FIG. 2) as a linear second light diffusion portion between the linear light diffusion portion 12A and the linear light diffusion portion 12B. , 4). The linear light diffusion portion 13 can be formed by a plurality of grooves 13A formed in the second main plane 9. The groove 13A is a groove whose longitudinal direction is parallel to the parallel direction of the plurality of LEDs 3A and 3B. That is, the groove 13 </ b> A is parallel to the end surfaces 6 and 7 and is formed from one end edge in the left-right direction of the second main plane 9 to the other end edge.
　溝１２ＡＡ，１２ＢＢおよび溝１３Ａは、たとえば、第１主平面８あるいは第２主平面９に対して切削により形成したり、あるいは、導光板本体４を成形型により製造する場合には、成形時に同時に型の転写形状として形成することもできる。また、線状光拡散部１２Ａ，１２Ｂおよび線状光拡散部１３は、凸条にて形成してもよい。 The grooves 12AA, 12BB and the groove 13A are formed, for example, by cutting the first main plane 8 or the second main plane 9, or when the light guide plate body 4 is manufactured by a mold, simultaneously with the molding. It can also be formed as a mold transfer shape. Moreover, you may form the linear light- diffusion parts 12A and 12B and the linear light-diffusion part 13 with a protruding item | line.
　溝１２ＡＡ，１２ＢＢの溝の幅および深さは、溝１３Ａに比べて幅広であり深い形状となっている。また、溝１２ＡＡ同士が隣接する間隔（複数の溝１２ＡＡの前後方向の形成ピッチ）は、溝１３Ａ同士が隣接する間隔（複数の溝１３Ａの前後方向の形成ピッチ）に比べて密に形成されている。複数の溝１２ＢＢの前後方向の形成ピッチも複数の溝１３Ａの前後方向の形成ピッチに比べて密に形成されている。 The groove widths and depths of the grooves 12AA and 12BB are wider and deeper than the groove 13A. Further, the interval between adjacent grooves 12AA (formation pitch in the front-rear direction of the plurality of grooves 12AA) is formed denser than the interval adjacent to each other groove 13A (formation pitch in the front-rear direction of the plurality of grooves 13A). Yes. The formation pitch in the front-rear direction of the plurality of grooves 12BB is also formed denser than the formation pitch in the front-rear direction of the plurality of grooves 13A.
（反射板５）
　反射板５は、導光板本体４の第２主平面９と対向する面に、たとえば、アルミ蒸着を施すことで反射面５Ａが形成されている。反射板５は、第２主平面９の全面に対向する形状であることが好ましい。すなわち、反射板５は、平面視において導光板本体４と同一の形状か、あるいは第２主平面９よりも若干輪郭において大きいことが好ましい。これにより、後述するように第２主平面９から出射した光を導光板本体４側に反射させる光量を増やすことができる。また、反射板５は、反射面５Ａを導光板本体４の第２主平面９に平行に対向するように配置される。なお、反射板５を備える代わりに、導光板本体４の第２主平面９に反射シートを貼着したり、あるいは、第２主平面９に直接、たとえば、アルミ蒸着を施すことで、第２主平面９の外側に反射面を形成し、反射手段としてもよい。 (Reflector 5)
The reflecting plate 5 has a reflecting surface 5A formed on the surface of the light guide plate body 4 facing the second main plane 9 by, for example, aluminum vapor deposition. The reflecting plate 5 preferably has a shape facing the entire surface of the second main plane 9. That is, it is preferable that the reflecting plate 5 has the same shape as that of the light guide plate main body 4 in a plan view or is slightly larger in outline than the second main plane 9. Thereby, the light quantity which reflects the light radiate | emitted from the 2nd main plane 9 to the light-guide plate main body 4 side can be increased so that it may mention later. The reflecting plate 5 is disposed so that the reflecting surface 5A faces the second main plane 9 of the light guide plate body 4 in parallel. Instead of providing the reflecting plate 5, the second main plane 9 of the light guide plate main body 4 is attached with a reflecting sheet, or the second main plane 9 is directly subjected to, for example, aluminum vapor deposition, so that the second A reflecting surface may be formed outside the main plane 9 to serve as reflecting means.
（出射光の出射効率の向上および輝度の均一化）
　次に、照明装置１のＬＥＤ３Ａ，３Ｂの出射光が、端面６，７から導光板２に入射し、導光板２から出射するまでの光の進行の様子を説明する。 (Improved emission efficiency and uniform brightness)
Next, how the light emitted from the LEDs 3 </ b> A and 3 </ b> B of the lighting device 1 enters the light guide plate 2 from the end faces 6 and 7 and proceeds from the light guide plate 2 will be described.
　先ず、ＬＥＤ３Ａから出射し、導光板本体４の端面６から導光板本体４内に入射した光の進行について説明する。端面６から導光板本体４に入射した光の一部は、導光板本体４内を透過し、直接、第１主平面８から導光板本体４の上方に出射する。また、他の一部の光は、第２主平面９から反射板５の側に出射し、反射面５Ａで反射され、再び導光板本体４を透過して第１主平面８から上方に出射する。 First, the progression of light emitted from the LED 3A and incident into the light guide plate body 4 from the end face 6 of the light guide plate body 4 will be described. A part of the light incident on the light guide plate main body 4 from the end face 6 is transmitted through the light guide plate main body 4 and directly emitted from the first main plane 8 to the upper side of the light guide plate main body 4. The other part of the light is emitted from the second main plane 9 toward the reflecting plate 5, reflected by the reflecting surface 5 </ b> A, again transmitted through the light guide plate body 4, and emitted upward from the first main plane 8. To do.
　第２主平面９には、線状光拡散部１３が形成されている。線状光拡散部１３を形成する複数の溝１３Ａは、各々、端面６側に斜面を向けた傾斜面１３Ｂを有する。第２主平面９に傾斜面１３Ｂが形成されることで、第２主平面９の線状光拡散部１３の領域が平面だけで構成される場合に比べて、ＬＥＤ３Ａから出射された光が第２主平面９で全反射する光量を低減でき、第２主平面９を透過する光量を増加させことができる。つまり、第２主平面９に線状光拡散部１３を形成することで、ＬＥＤ３Ａから出射された光が、第２主平面９から反射面５Ａ側に出射する量を増やすことができる。反射面５Ａ側に出射された光は、反射面５Ａで反射され導光板本体４を透過して第１主平面８から上方に出射する。そのため、第２主平面９に線状光拡散部１３を形成することで、第１主平面８からの出射する光の量を増やすことができる。 A linear light diffusion portion 13 is formed on the second main plane 9. Each of the plurality of grooves 13 </ b> A forming the linear light diffusion portion 13 has an inclined surface 13 </ b> B with an inclined surface facing the end surface 6 side. By forming the inclined surface 13B on the second main plane 9, the light emitted from the LED 3A can be compared with the case where the area of the linear light diffusion portion 13 of the second main plane 9 is composed of only a plane. The amount of light totally reflected by the two main planes 9 can be reduced, and the amount of light transmitted through the second main plane 9 can be increased. That is, by forming the linear light diffusion portion 13 on the second main plane 9, the amount of light emitted from the LED 3A can be increased from the second main plane 9 toward the reflecting surface 5A. The light emitted to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate main body 4, and is emitted upward from the first main plane 8. Therefore, the amount of light emitted from the first main plane 8 can be increased by forming the linear light diffusion portion 13 on the second main plane 9.
　隣接するＬＥＤ３Ｂの照射範囲と照射範囲との間の照射範囲外となる領域は、輝度が低くなり易い。具体的には、点状光拡散部１０Ｂが形成される領域は、隣接するＬＥＤ３ＢとＬＥＤ３Ｂの照射角の範囲外となる領域となり易く、輝度が低くなり易い。この点に着目し、導光板２では、第２主平面９の端面７側の周縁部９Ｂに線状光拡散部１２Ｂを形成することで、ＬＥＤ３ＢとＬＥＤ３Ｂの間の領域の輝度の向上を図っている。 The area outside the irradiation range between the irradiation ranges of the adjacent LEDs 3B tends to be low in luminance. Specifically, the area where the dotted light diffusing portion 10B is formed tends to be an area outside the irradiation angle range of the adjacent LED 3B and LED 3B, and the luminance tends to be low. Focusing on this point, in the light guide plate 2, the linear light diffusion portion 12B is formed on the peripheral edge portion 9B on the end surface 7 side of the second main plane 9, thereby improving the luminance of the region between the LED 3B and the LED 3B. ing.
　つまり、線状光拡散部１２Ｂを形成する複数の溝１２ＢＢは、各々、端面６側に斜面を向けた傾斜面１２ＢＣを有する。第２主平面９の線状光拡散部１２Ｂの領域が平面だけで構成される場合に比べて、傾斜面１２ＢＣが形成されることで、ＬＥＤ３Ａから出射された光が第２主平面９で全反射する光量を低減でき、第２主平面９を透過する光量を増加させることができる。線状光拡散部１２Ｂが形成される領域から反射面５Ａ側に出射された光は、反射面５Ａで反射され導光板本体４を透過して、主に、第１主平面８の点状光拡散部１０Ｂを含む領域から上方に出射する。したがって、第２主平面９に線状光拡散部１２Ｂを形成することで、第１主平面８の点状光拡散部１０Ｂを含む領域から出射する光の量を増やすことができる。 That is, each of the plurality of grooves 12BB forming the linear light diffusion portion 12B has an inclined surface 12BC with the inclined surface facing the end surface 6 side. Compared with the case where the region of the linear light diffusion portion 12B of the second main plane 9 is configured by only a plane, the inclined surface 12BC is formed, so that the light emitted from the LED 3A is entirely emitted from the second main plane 9. The amount of light reflected can be reduced, and the amount of light transmitted through the second main plane 9 can be increased. The light emitted from the region where the linear light diffusing portion 12B is formed to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate body 4, and is mainly dotted light on the first main plane 8. The light is emitted upward from the region including the diffusion portion 10B. Therefore, by forming the linear light diffusion portion 12B on the second main plane 9, the amount of light emitted from the region including the point light diffusion portion 10B on the first main plane 8 can be increased.
　次に、ＬＥＤ３Ｂから出射し、導光板本体４の端面７から導光板本体４内に入射した光の進行について説明する。ＬＥＤ３Ｂから出射した光は、導光板本体４の端面７から導光板本体４内に入射し、上述したＬＥＤ３Ａから出射した光と同様に、光の一部は、直接、第１主平面８から導光板本体４の上方に出射し、他の一部の光は、第２主平面９から反射板５の側に出射し、反射面５Ａで反射され、再び導光板本体４を透過して第１主平面８から上方に出射する。 Next, the progression of light emitted from the LED 3B and entering the light guide plate body 4 from the end face 7 of the light guide plate body 4 will be described. The light emitted from the LED 3B enters the light guide plate body 4 from the end face 7 of the light guide plate body 4, and a part of the light is guided directly from the first main plane 8 in the same manner as the light emitted from the LED 3A. The other part of the light emitted above the optical plate body 4 is emitted from the second main plane 9 toward the reflection plate 5, reflected by the reflection surface 5A, and transmitted through the light guide plate body 4 again to the first. The light is emitted upward from the main plane 8.
　線状光拡散部１３を形成する複数の溝１３Ａは、各々、端面７側に斜面を向けた傾斜面１３Ｃを有する。したがって、上述した傾斜面１３Ｂと同様に、ＬＥＤ３Ｂから出射した光が、第２主平面９で全反射される量を低減され、第２主平面９から反射面５Ａ側に出射する量を増やすことができる。反射面５Ａ側に出射された光は、反射面５Ａで反射され導光板本体４を透過して第１主平面８から上方に出射するため、第１主平面８からの出射する光の量を増やすことができる。 Each of the plurality of grooves 13A forming the linear light diffusion portion 13 has an inclined surface 13C with the inclined surface facing the end surface 7 side. Therefore, similarly to the above-described inclined surface 13B, the amount of light emitted from the LED 3B is totally reflected on the second main plane 9, and the amount of light emitted from the second main plane 9 toward the reflecting surface 5A is increased. Can do. The light emitted to the reflective surface 5A side is reflected by the reflective surface 5A, passes through the light guide plate body 4, and is emitted upward from the first main plane 8, so that the amount of light emitted from the first main plane 8 is reduced. Can be increased.
　隣接するＬＥＤ３Ａの照射範囲と照射範囲との間の照射範囲外となる領域は、輝度が低くなり易い。具体的には、点状光拡散部１０Ａが形成される領域は、隣接するＬＥＤ３ＡとＬＥＤ３Ａの照射角の範囲外となる領域となり易く、輝度が低くなり易い。この点に着目し、導光板２では、第２主平面９の端面６側の周縁部９Ａに線状光拡散部１２Ａを形成することで、ＬＥＤ３ＡとＬＥＤ３Ａの間の領域の輝度の向上を図っている。 The area outside the irradiation range between the irradiation ranges of the adjacent LEDs 3A tends to be low in luminance. Specifically, the area where the dotted light diffusion portion 10A is formed is likely to be an area outside the range of the irradiation angle of the adjacent LED 3A and LED 3A, and the luminance is likely to be low. Focusing on this point, in the light guide plate 2, the linear light diffusion portion 12A is formed on the peripheral edge portion 9A on the end surface 6 side of the second main plane 9, thereby improving the luminance of the region between the LED 3A and the LED 3A. ing.
　つまり、線状光拡散部１２Ａを形成する複数の溝１２ＡＡは、各々、端面７側に斜面を向けた傾斜面１２ＡＣを有する。第２主平面９の線状光拡散部１２Ａの領域が平面だけで構成される場合に比べて、傾斜面１２ＡＣが形成されることで、ＬＥＤ３Ｂから出射した光が第２主平面９で全反射される光量を低減でき、第２主平面９を透過する光量を増加させることができる。線状光拡散部１２Ａが形成される領域から反射面５Ａ側に出射された光は、反射面５Ａで反射され導光板本体４を透過して、主に、第１主平面８の点状光拡散部１０Ａを含む領域から上方に出射する。したがって、第２主平面９に線状光拡散部１２Ａを形成することで、第１主平面８の点状光拡散部１０Ａを含む領域から出射する光の量を増やすことができる。 That is, each of the plurality of grooves 12AA forming the linear light diffusion portion 12A has an inclined surface 12AC with the inclined surface facing the end surface 7 side. Compared with the case where the area of the linear light diffusing portion 12A of the second main plane 9 is composed of only a plane, the inclined surface 12AC is formed so that the light emitted from the LED 3B is totally reflected by the second main plane 9. The amount of light transmitted can be reduced, and the amount of light transmitted through the second main plane 9 can be increased. The light emitted from the region where the linear light diffusing portion 12A is formed to the reflecting surface 5A side is reflected by the reflecting surface 5A, passes through the light guide plate body 4, and is mainly point-like light on the first main plane 8. The light is emitted upward from the region including the diffusion portion 10A. Therefore, by forming the linear light diffusion portion 12A on the second main plane 9, the amount of light emitted from the region including the point light diffusion portion 10A on the first main plane 8 can be increased.
　上述したように、第２主平面９に線状光拡散部１２Ａ、線状光拡散部１２Ｂおよび線状光拡散部１３が形成されることで、ＬＥＤ３Ａ，３Ｂから導光板本体４に入射した光が第１主平面８から出射される出射効率が図られる。また、線状光拡散部１２Ａ，１２Ｂが形成されることで、隣接するＬＥＤ３ＡとＬＥＤ３Ｂの照射角の範囲外となる輝度が低い領域の輝度を向上させることができ、第１主平面８の輝度の均一化を図ることができる。 As described above, the light incident on the light guide plate body 4 from the LEDs 3A and 3B is formed by forming the linear light diffusion portion 12A, the linear light diffusion portion 12B, and the linear light diffusion portion 13 on the second main plane 9. Is emitted from the first main plane 8. In addition, since the linear light diffusion portions 12A and 12B are formed, it is possible to improve the luminance of the low-luminance region outside the irradiation angle range of the adjacent LED 3A and LED 3B, and the luminance of the first main plane 8 Can be made uniform.
　また、導光板本体４内の光は、第２主平面９から反射面５Ａ側に出射する際、線状光拡散部１２Ａ、線状光拡散部１２Ｂあるいは線状光拡散部１３により拡散された状態で出射する。さらに、第２主平面９から出射した光は、反射面５Ａで反射され再び第２主平面９に入射する際にも、線状光拡散部１２Ａ、線状光拡散部１２Ｂあるいは線状光拡散部１３により拡散される。つまり、線状光拡散部１２Ａ、線状光拡散部１２Ｂおよび線状光拡散部１３は、ＬＥＤ３Ａ，３Ｂから導光板本体４に入射した光の第１主平面８からの出射効率の向上を図ることに加えて、光の拡散を行うことで第１主平面８における輝度の均一化にも寄与する。 In addition, the light in the light guide plate body 4 is diffused by the linear light diffusing portion 12A, the linear light diffusing portion 12B, or the linear light diffusing portion 13 when emitted from the second main plane 9 to the reflecting surface 5A. The state is emitted. Furthermore, when the light emitted from the second main plane 9 is reflected by the reflecting surface 5A and enters the second main plane 9 again, the linear light diffusion portion 12A, the linear light diffusion portion 12B, or the linear light diffusion is used. It is diffused by the part 13. That is, the linear light diffusing portion 12A, the linear light diffusing portion 12B, and the linear light diffusing portion 13 improve the emission efficiency from the first main plane 8 of the light incident on the light guide plate body 4 from the LEDs 3A and 3B. In addition, the diffusion of light contributes to uniform brightness in the first main plane 8.
　ＬＥＤ３Ａ，３Ｂから出射し導光板本体４内に入射した光は、上述したように、導光板本体４を透過し、直接、第１主平面８から出射したり、あるいは、導光板本体４から反射面５Ａ側に出射した後、反射面５Ａで反射され、再び導光板本体４を透過して第１主平面８から上方に出射する。第１主平面８には、点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１が形成されている。導光板本体４から点状光拡散部１０Ａ，１０Ｂあるいは点状光拡散部１１を透過して出射する光は、点状光拡散部１０Ａ，１０Ｂあるいは点状光拡散部１１により拡散されて出射される。つまり、第１主平面８に点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１が形成されることで、第１主平面８における輝度の均一化が図られる。 The light emitted from the LEDs 3A and 3B and entering the light guide plate main body 4 is transmitted through the light guide plate main body 4 and directly emitted from the first main plane 8 or reflected from the light guide plate main body 4 as described above. After exiting to the surface 5A side, it is reflected by the reflecting surface 5A, passes through the light guide plate body 4 again, and exits upward from the first main plane 8. On the first main plane 8, point light diffusion portions 10 </ b> A and 10 </ b> B and a point light diffusion portion 11 are formed. Light emitted from the light guide plate body 4 through the point light diffusion portions 10A and 10B or the point light diffusion portions 11 is diffused and emitted by the point light diffusion portions 10A and 10B or the point light diffusion portions 11. The That is, by forming the point light diffusing portions 10A and 10B and the point light diffusing portion 11 on the first main plane 8, the luminance on the first main plane 8 is made uniform.
　点状光拡散部１０Ａには、主に線状光拡散部１２Ａを透過した光が入射し、拡散され出射される。つまり、線状光拡散部１２Ａにより、点状光拡散部１０Ａを含む領域から出射する光の輝度の均一化が図られる。また、線状光拡散部１２Ａは、ＬＥＤ３Ｂから出射し、導光板本体４を進行し線状光拡散部１２Ａに到達した光が線状光拡散部１２Ａで拡散され第１主平面８から出射する。したがって、線状光拡散部１２Ａは、第１主平面８の線状光拡散部１２Ａにおける出射効率を上げることもできる。 The light transmitted mainly through the linear light diffusion portion 12A is incident on the point light diffusion portion 10A, and is diffused and emitted. That is, the linear light diffusing unit 12A can make the luminance of the light emitted from the region including the point light diffusing unit 10A uniform. Further, the linear light diffusion portion 12A is emitted from the LED 3B, and the light that travels through the light guide plate body 4 and reaches the linear light diffusion portion 12A is diffused by the linear light diffusion portion 12A and emitted from the first main plane 8. . Therefore, the linear light diffusion portion 12A can also increase the emission efficiency in the linear light diffusion portion 12A of the first main plane 8.
　点状光拡散部１０Ｂには、主に線状光拡散部１２Ｂを透過した光が入射し、拡散され出射される。つまり、線状光拡散部１２Ｂにより、点状光拡散部１０Ｂを含む領域から出射する光の輝度の均一化が図られる。また、線状光拡散部１２Ｂは、ＬＥＤ３Ａから出射し、導光板本体４を進行し線状光拡散部１２Ｂに到達した光が線状光拡散部１２Ｂで拡散され第１主平面８から出射する。したがって、線状光拡散部１２Ｂは、第１主平面８の線状光拡散部１２Ｂにおける出射効率を上げることもできる。 The light transmitted mainly through the linear light diffusion portion 12B is incident on the point light diffusion portion 10B, and is diffused and emitted. That is, the linear light diffusing unit 12B makes it possible to make the luminance of light emitted from the region including the point light diffusing unit 10B uniform. Further, the linear light diffusion portion 12B is emitted from the LED 3A, and the light that travels through the light guide plate body 4 and reaches the linear light diffusion portion 12B is diffused by the linear light diffusion portion 12B and emitted from the first main plane 8. . Therefore, the linear light diffusion portion 12B can also increase the emission efficiency in the linear light diffusion portion 12B on the first main plane 8.
　さらに、点状光拡散部１１には、主に線状光拡散部１３を透過した光、あるいは、ＬＥＤ３Ａ，３Ｂから出射し、導光板本体４を進行し点状光拡散部１１に到達した光が、進行し点状光拡散部１１で拡散され第１主平面８から出射する。したがって、進行し点状光拡散部１１は、第１主平面８の点状光拡散部１１における出射効率を上げることもできる。 Further, the point light diffusing unit 11 mainly transmits light transmitted through the linear light diffusing unit 13 or light emitted from the LEDs 3A and 3B, travels through the light guide plate body 4 and reaches the point light diffusing unit 11. However, it progresses and is diffused by the point light diffusion part 11 and is emitted from the first main plane 8. Therefore, the point light diffusing unit 11 that travels can increase the emission efficiency of the point light diffusing unit 11 on the first main plane 8.
　上述の実施の形態では、線状光拡散部１２Ａ，１２Ｂおよび線状光拡散部１３を形成する溝１２ＡＡ，１２ＢＢおよび溝１３Ａの断面の形状は、略三角形を呈している。しかしながら、該溝の断面形状は、端面６，７に向く斜面を有すれば三角形に限らず、たとえば、略半円形や台形等とすることもできる。また、線状光拡散部１２Ａ，１２Ｂおよび線状光拡散部１３は、溝とする替りに、下方、すなわち反射面５Ａ側に突出する凸条にて形成してもよい。 In the above-described embodiment, the cross-sectional shapes of the grooves 12AA and 12BB and the grooves 13A forming the linear light diffusion portions 12A and 12B and the linear light diffusion portion 13 are substantially triangular. However, the cross-sectional shape of the groove is not limited to a triangle as long as it has an inclined surface facing the end faces 6 and 7, and may be, for example, a substantially semicircular shape or a trapezoid. Further, the linear light diffusing portions 12A and 12B and the linear light diffusing portion 13 may be formed by ridges projecting downward, that is, toward the reflecting surface 5A, instead of being grooves.
　導光板２は、上述したように、並列される複数の光源である複数のＬＥＤ３Ａと複数のＬＥＤ３Ｂから出射される光が入射し、互いに対向して配置される第１端面としての端面６および第２端面としての端面７と、　各端面６，７から入射した複数のＬＥＤ３Ａ，３Ｂからの光が出射する互いに対向して配置される第１主平面８および第２主平面９と、　第２主平面９に対向して配置され、第２主平面９から出射された光を第２主平面９側に反射する反射手段としての反射板５とを有する。そして、第１主平面８には、複数のＬＥＤ３Ａの隣り合うＬＥＤ３Ａの間に対応した領域に、端面６および端面７の各端面から他方の端面に向かうに従って幅が狭くなる第１光拡散部としての点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂが形成されている。第１主平面８および第２主平面９のうち、いずれか一方の主平面である第１主平面８には、点状光拡散部１０Ａ，１０Ｂが形成され、他方の主平面である第２主平面９には、線状光拡散部１２Ａ，１２Ｂが形成されている。点状光拡散部１０Ａ，１０Ｂは、多数の突起または穴の集合にて形成される。線状光拡散部１２Ａ，１２Ｂは、長さ方向が並列される複数のＬＥＤ３Ａ，３Ｂの並列方向に平行な多数の凸条または溝の集合にて形成される。 As described above, the light guide plate 2 receives the light emitted from the plurality of LEDs 3A and the plurality of LEDs 3B, which are a plurality of light sources arranged in parallel, and the end surface 6 as the first end surface disposed opposite to each other and the first surface 6 An end face 7 as two end faces, a first main plane 8 and a second main plane 9 arranged opposite to each other, which emit light from the plurality of LEDs 3A and 3B incident from the end faces 6 and 7; A reflecting plate 5 is disposed as opposed to the plane 9 and serves as reflecting means for reflecting the light emitted from the second main plane 9 to the second main plane 9 side. And in the 1st main plane 8, it is a 1st light-diffusion part where a width | variety becomes narrow as it goes to the other end surface from each end surface of the end surface 6 and the end surface 7 in the area | region corresponding between LED3A which adjoins several LED3A. The point light diffusion parts 10A and 10B and the linear light diffusion parts 12A and 12B are formed. Of the first main plane 8 and the second main plane 9, the first main plane 8, which is one of the main planes, is formed with point light diffusion portions 10A, 10B, and the second main plane is the second main plane. On the main plane 9, linear light diffusion portions 12A and 12B are formed. The point light diffusing portions 10A and 10B are formed by a set of a large number of protrusions or holes. The linear light diffusion portions 12A and 12B are formed by a set of a large number of ridges or grooves parallel to the parallel direction of the plurality of LEDs 3A and 3B whose length directions are parallel.
　導光板２がこのように構成されることで、ＬＥＤ３Ａ，３Ｂから出射し導光板本体４内に入射した光が、第１主平面８から出射する出射効率を向上させることができ、併せて、第１主平面８における輝度分布の均一化を図ることができる。また、隣接するＬＥＤ３ＢとＬＥＤ３Ｂの間の照射角の範囲外となる領域、および隣接するＬＥＤ３ＡとＬＥＤ３Ａの間の照射角の範囲外となる領域は輝度が低くなり易い。しかしながら、導光板本体４に点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂが形成されることで、第１主平面８の該輝度が低くなり易い領域から出射する光の出射光量の向上および輝度分布の均一化が図られる。 By configuring the light guide plate 2 in this way, the light emitted from the LEDs 3A and 3B and entering the light guide plate main body 4 can improve the output efficiency of emitting from the first main plane 8, The luminance distribution on the first main plane 8 can be made uniform. Moreover, the brightness | luminance tends to become low in the area | region outside the range of the irradiation angle between adjacent LED3B and LED3B, and the area | region outside the range of the irradiation angle between adjacent LED3A and LED3A. However, by emitting the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B to the light guide plate body 4, the light emitted from the first main plane 8 where the luminance tends to be low is emitted. The light quantity can be improved and the luminance distribution can be made uniform.
　点状光拡散部１１は、各ＬＥＤ３ＡおよびＬＥＤ３Ｂの光軸からの距離が離れるほど、凹部あるいは凸部の形成密度が高くなることが好ましい。 It is preferable that the formation density of a recessed part or a convex part becomes high, so that the point-like light-diffusion part 11 leaves | separates the distance from the optical axis of each LED3A and LED3B.
　点状光拡散部１１が形成される部分は、導光板本体４を進行する光の第１主平面８における全反射が破られ易い。したがって、点状光拡散部１１では、導光板本体４を進行する光の出射効率が向上する。 In the portion where the dotted light diffusing portion 11 is formed, the total reflection on the first main plane 8 of the light traveling through the light guide plate body 4 is easily broken. Therefore, in the point light diffusion part 11, the emission efficiency of light traveling through the light guide plate body 4 is improved.
　ＬＥＤ３Ａ，３Ｂの光軸からの距離が離れるほど、ＬＥＤ３Ａ，３Ｂから出射される光の強度は弱まる。そこで、各ＬＥＤ３ＡおよびＬＥＤ３Ｂの光軸からの距離が離れるほど、点状光拡散部１１を構成する凹部あるいは凸部の形成密度を高くすることにより、ＬＥＤ３Ａ，３Ｂの光軸からの距離が離れた位置での光の出射効率を向上させることができ、第１主平面８における光の出射効率の輝度の均一化を図ることができる。 The intensity of light emitted from the LEDs 3A and 3B decreases as the distance from the optical axis of the LEDs 3A and 3B increases. Therefore, as the distance from the optical axis of each LED 3A and LED 3B increases, the distance from the optical axis of the LEDs 3A and 3B increases by increasing the formation density of the concave portions or the convex portions constituting the point light diffusing portion 11. The light emission efficiency at the position can be improved, and the luminance of the light emission efficiency on the first main plane 8 can be made uniform.
　なお、点状光拡散部１１の凹部あるいは凸部の形成密度は、各ＬＥＤ３ＡおよびＬＥＤ３Ｂの光軸からの距離が離れるに従って徐々に高くなることが好ましい。徐々に高くすることで、輝度分布の変化が滑らかになり第１主平面８の輝度分布の均一化を図ることができる。 In addition, it is preferable that the formation density of the recessed part or convex part of the dotted | punctate light-diffusion part 11 becomes high gradually as the distance from the optical axis of each LED3A and LED3B leaves | separates. By gradually increasing the luminance distribution, the luminance distribution changes smoothly, and the luminance distribution of the first main plane 8 can be made uniform.
　点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂは、ＬＥＤ３Ａ，３Ｂの照射角の７０％よりも外側の範囲に形成されることが好ましい。 It is preferable that the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed in a range outside 70% of the irradiation angle of the LEDs 3A and 3B.
　点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂでは、導光板本体４内を進行する光の出射効率が高くなる。そのため、仮に、ＬＥＤ３Ａ，３Ｂの光軸上に点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂを形成すると、もともと輝度の高い部分での光の出射効率が高くなってしまい、光軸から離れた輝度の低い部分へ進行する光の量が低減されてしまう。 In the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B, the light emission efficiency of light traveling in the light guide plate body 4 is increased. Therefore, if the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed on the optical axes of the LEDs 3A and 3B, the light emission efficiency in the originally high luminance portion is increased. The amount of light traveling to the low-luminance part away from the optical axis is reduced.
　そこで、点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂは、ＬＥＤ３Ａ，３Ｂの照射角の７０％よりも外側の範囲に形成し、ＬＥＤ３Ａ，３Ｂの光軸に近い領域での光の出射量を減らすことで、該光軸から遠い輝度の低下し易い領域に進行する光の量を増やすことができる。 Therefore, the point light diffusing portions 10A and 10B and the linear light diffusing portions 12A and 12B are formed in a range outside 70% of the irradiation angle of the LEDs 3A and 3B, and in a region close to the optical axis of the LEDs 3A and 3B. By reducing the amount of emitted light, the amount of light traveling to a region far from the optical axis where the luminance tends to decrease can be increased.
　導光板２は、端面６と端面７との間隔が３０ｍｍ以上８０ｍｍ以下であることが好ましい。 The light guide plate 2 preferably has an interval between the end surface 6 and the end surface 7 of 30 mm or more and 80 mm or less.
　導光板２のサイズが小さくなるほど、ＬＥＤ３Ａ，３Ｂから出射した光が導光板本体４内で拡散される回数が減り、輝度斑が生じやすくなる。しかしながら、上述したように、導光板本体４と反射板５を備え、導光板本体４に点状光拡散部１０Ａ，１０Ｂおよび線状光拡散部１２Ａ，１２Ｂを形成することで、端面６と端面７との間隔が３０ｍｍ以上８０ｍｍ以下であっても、第１主平面８における光出射効率の向上と輝度分布の均一化を図ることができる。さらに、点状光拡散部１１および線状光拡散部１３が形成されることで、第１主平面８における光の出射効率の向上と輝度分布の均一化が一層図られる。 As the size of the light guide plate 2 is reduced, the number of times the light emitted from the LEDs 3A and 3B is diffused in the light guide plate body 4 is reduced, and luminance spots are more likely to occur. However, as described above, the light guide plate body 4 and the reflection plate 5 are provided, and the end face 6 and the end face are formed by forming the point light diffusion portions 10A and 10B and the linear light diffusion portions 12A and 12B in the light guide plate body 4. Even if the distance to 7 is not less than 30 mm and not more than 80 mm, the light emission efficiency in the first main plane 8 can be improved and the luminance distribution can be made uniform. Furthermore, by forming the point light diffusing portion 11 and the linear light diffusing portion 13, it is possible to further improve the light emission efficiency and make the luminance distribution uniform in the first main plane 8.
　ＬＥＤ３Ａ，３Ｂが、たとえば、図５に示すように、ＬＥＤチップ２０をカップ状の反射板２１内に配置されている構成のものを用いることができる。この場合、導光板本体４の厚さ、すなわち第１主平面８と第２主平面９との間隔Ｄは、反射板２１の開口径Ｒ以上であり開口径Ｒの３倍以下であることが好ましい。 As the LEDs 3A and 3B, for example, as shown in FIG. 5, a configuration in which the LED chip 20 is disposed in a cup-shaped reflecting plate 21 can be used. In this case, the thickness of the light guide plate body 4, that is, the distance D between the first main plane 8 and the second main plane 9 is not less than the opening diameter R of the reflecting plate 21 and not more than three times the opening diameter R. preferable.
　導光板本体４の厚さが、開口径Ｒ未満となると、ＬＥＤ３Ａ，３Ｂから出射した光が端面６，７に入射しきれず漏れてしまう量が増え適当でない。一方、導光板本体４の厚さが増すほど、一方の端面（端面６または端面７）から他方の端面（端面７または端面６）に進行する光が第１主平面８と第２主平面９との間で反射を繰り返す回数が減る。そのため、端面６，７から入射した光が、点状光拡散部１０Ａ，１０Ｂ、線状光拡散部１２Ａ，１２Ｂ、点状光拡散部１１あるいは線状光拡散部１３により拡散される回数が減り、出射効率の向上や輝度分布の均一化を図り難くなる。したがって、導光板本体４の厚さを、開口径Ｒ以上であり開口径Ｒの３倍以下とすることで、ＬＥＤ３Ａ，３Ｂから出射した光の端面６，７への入射効率を上げることができると共に、第１主平面８から出射する光の出射効率と輝度分布の均一化を効率的に図ることができる。 If the thickness of the light guide plate body 4 is less than the opening diameter R, the amount of light emitted from the LEDs 3A and 3B cannot be incident on the end faces 6 and 7 and increases, which is not appropriate. On the other hand, as the thickness of the light guide plate body 4 increases, the light traveling from one end face (end face 6 or end face 7) to the other end face (end face 7 or end face 6) becomes the first main plane 8 and the second main plane 9. Reduces the number of reflections between and. Therefore, the number of times the light incident from the end faces 6 and 7 is diffused by the point light diffusion portions 10A and 10B, the linear light diffusion portions 12A and 12B, the point light diffusion portion 11 or the linear light diffusion portion 13 is reduced. It becomes difficult to improve the emission efficiency and make the luminance distribution uniform. Therefore, by making the thickness of the light guide plate body 4 not less than the opening diameter R and not more than three times the opening diameter R, the incident efficiency of the light emitted from the LEDs 3A and 3B to the end faces 6 and 7 can be increased. At the same time, the emission efficiency of the light emitted from the first main plane 8 and the luminance distribution can be made uniform efficiently.
　なお、点状光拡散部１０Ａは、端面６側に近いほど密に突起または穴が形成され、端面６から遠ざかるにしたがって粗となるように形成することが好ましい。点状光拡散部１０Ｂも同様に、端面７側に近いほど密に突起または穴が形成され、端面７から遠ざかるにしたがって粗となるように形成することが好ましい。さらに、線状光拡散部１２Ａは、端面６側に近いほど密に凸条または溝が形成され、端面６から遠ざかるにしたがって粗となるように形成することが好ましい。そして、線状光拡散部１２Ｂも同様に、端面７側に近いほど密に凸条または溝が形成され、端面７から遠ざかるにしたがって粗となるように形成することが好ましい。このようにすることによって、隣接するＬＥＤ３ＡとＬＥＤ３Ａとの間、および隣接するＬＥＤ３ＢとＬＥＤ３Ｂとの間の暗くなる位置や、ＬＥＤ３ＡやＬＥＤ３Ｂが配置されない左右の端部位置における明るさの落ち込みを効果的に低減でき、導光板２の光出射面である第１主平面８の輝度の均一化をより効果的に図ることができる。 In addition, it is preferable that the spot-like light diffusing portion 10 </ b> A is formed so that projections or holes are densely formed closer to the end face 6 side and become rougher as it is farther from the end face 6. Similarly, it is preferable that the spot-like light diffusing portion 10 </ b> B is formed so that projections or holes are densely formed closer to the end surface 7 side and become rougher as it is farther from the end surface 7. Furthermore, it is preferable that the linear light diffusing portion 12 </ b> A is formed so that convex ridges or grooves are densely formed closer to the end surface 6 side and become rougher as the distance from the end surface 6 increases. Similarly, it is preferable that the linear light diffusing portion 12B is formed so that convex ridges or grooves are formed closer to the end face 7 side and become rougher as the distance from the end face 7 increases. By doing in this way, it is effective in the brightness fall in the darkening position between adjacent LED3A and LED3A and between adjacent LED3B and LED3B, and the edge part position on either side where LED3A and LED3B are not arrange | positioned. The brightness of the first main plane 8 that is the light exit surface of the light guide plate 2 can be made more uniform.
　なお、点状光拡散部１０Ａ，１０Ｂは、粗面化処理によって形成された多数の微細な突起または穴で構成されているが、点状光拡散部１０Ａ，１０Ｂは、たとえば、微細な複数のレンズ形状の凹凸部等で形成してもよい。点状光拡散部１０Ａ，１０Ｂの凹凸形状は、凸レンズ形状、凹レンズ形状、円錐形状の凹凸部を設ける構造としてもよい。 In addition, although the dotted | punctate light- diffusion parts 10A and 10B are comprised by many fine processus | protrusions or holes formed by the roughening process, the dotted | punctate light- diffusion parts 10A and 10B are a fine several, for example You may form with a lens-shaped uneven part. The concavo-convex shape of the point light diffusion portions 10A and 10B may be a structure in which a convex lens shape, a concave lens shape, or a conical concavo-convex portion is provided.
（第２の実施の形態）
　図６の上段（Ａ）および下段（Ｂ）に示すように、端面６の点状光拡散部１０Ａおよび線状光拡散部１２Ａに対応した部分と、端面７の点状光拡散部１０Ｂおよび線状光拡散部１２Ｂに対応した部分とは、下方（第２主平面９側）から上方（第１主平面８側）に向かって、互いに間隔が広くなる斜面６Ａと斜面７Ａとを形成することが好ましい。 (Second Embodiment)
As shown in the upper part (A) and lower part (B) of FIG. 6, the part corresponding to the dotted light diffusing part 10 </ b> A and the linear light diffusing part 12 </ b> A on the end face 6, and the dotted light diffusing part 10 </ b> B and the line on the end face 7. The portion corresponding to the light diffusion portion 12B is formed with a slope 6A and a slope 7A that are spaced apart from each other from the lower side (second main plane 9 side) to the upper side (first main plane 8 side). Is preferred.
　斜面６Ａ，７Ａを形成することで、ＬＥＤ３Ａ，３Ｂから出射した光を第１主平面８から出射させる出射効率の向上を図ることができる。つまり、ＬＥＤ３Ａから出射し端面６から導光板本体４に入射し斜面７Ａに到達した光は、斜面７Ａで上側に向けて反射される。また、ＬＥＤ３Ｂから出射し端面７から導光板本体４に入射し斜面６Ａに到達した光は、斜面６Ａで上側に向けて反射される。これにより、ＬＥＤ３Ａ，３Ｂから出射した光を第１主平面８から出射させる出射効率の向上を図ることができる。 By forming the inclined surfaces 6A and 7A, it is possible to improve the emission efficiency of emitting the light emitted from the LEDs 3A and 3B from the first main plane 8. That is, the light emitted from the LED 3A, incident on the light guide plate body 4 from the end face 6 and reaches the inclined surface 7A is reflected upward by the inclined surface 7A. Further, the light emitted from the LED 3B, incident on the light guide plate main body 4 from the end surface 7 and reaches the slope 6A is reflected upward by the slope 6A. Thereby, it is possible to improve the emission efficiency of emitting the light emitted from the LEDs 3A and 3B from the first main plane 8.
（第３の実施の形態）
　図７，８に示すように、導光板２は、第１主平面８の上方に拡散板３０と、光遮蔽部材としての遮光板３１を備えた構成としてもよい。拡散板３０は、導光板２の導光板本体４の側に、第１主平面８から出射した光が入射する光入射面３２と、この光入射面３２から入射した光が出射する光出射面３３を有する。また、拡散板３０の前後には、凸条部３４が形成されている。凸条部３４は、導光板本体４側に突出し、導光板本体４の第１主平面８の点状光拡散部１０Ａが形成される縁部である周縁部８Ａ（図１，３参照）と、点状光拡散部１０Ｂが形成される縁部である周縁部８Ｂ（図１，３参照）とに対向する位置に設けられている。凸条部３４の下面には、周縁部８Ａ，８Ｂから出射する光が入射する光入射面である周縁光入射面３５が形成されている。拡散板３０の前後の凸条部３４の間は、凹部３６として形成されている。凹部３６の底面である光入射面３２は、第１主平面８から出射した光が入射する光入射面として形成されている。 (Third embodiment)
As shown in FIGS. 7 and 8, the light guide plate 2 may be configured to include a diffusion plate 30 and a light shielding plate 31 as a light shielding member above the first main plane 8. The diffusion plate 30 includes a light incident surface 32 on which light emitted from the first main plane 8 is incident on the light guide plate body 4 side of the light guide plate 2, and a light emission surface from which light incident from the light incident surface 32 is emitted. 33. In addition, on the front and rear sides of the diffuser plate 30, protruding line portions 34 are formed. The ridge 34 protrudes toward the light guide plate main body 4 and has a peripheral edge 8A (see FIGS. 1 and 3) that is an edge where the point light diffusion portion 10A of the first main plane 8 of the light guide plate main body 4 is formed. In addition, it is provided at a position facing the peripheral edge 8B (see FIGS. 1 and 3), which is an edge where the dotted light diffusion portion 10B is formed. On the lower surface of the ridge 34, a peripheral light incident surface 35, which is a light incident surface on which light emitted from the peripheral portions 8A and 8B is incident, is formed. A gap 36 is formed between the front and rear ridges 34 of the diffusion plate 30. The light incident surface 32 that is the bottom surface of the recess 36 is formed as a light incident surface on which light emitted from the first main plane 8 is incident.
　拡散板３０としては、たとえば、アクリル樹脂、ポリカーボネイト樹脂あるいはガラスなどの透明な材料に、光散乱粒子を混合することで、拡散板３０内に入射した光を散乱させ外部に出射できる構成となっている。光散乱粒子としては、たとえば、特開２０１０－９７０８８、特開２０１０－１２３３０９等に開示される光散乱粒子を用いることができる。また、拡散板３０は、光散乱粒子を混合する代わりに、拡散板３０の表面に粗面化処理を施すことにより、多数の孔または突起の集合にて凹凸面が形成される光散乱面を有する構成としてもよい。 As the diffusion plate 30, for example, light scattering particles are mixed with a transparent material such as acrylic resin, polycarbonate resin, or glass, so that light incident on the diffusion plate 30 can be scattered and emitted to the outside. Yes. As the light scattering particles, for example, the light scattering particles disclosed in JP2010-97088A, JP2010-123309A, and the like can be used. In addition, the diffuser plate 30 has a light scattering surface on which an uneven surface is formed by a collection of a large number of holes or protrusions by performing a roughening treatment on the surface of the diffuser plate 30 instead of mixing light scattering particles. It is good also as a structure to have.
　拡散板３０は、平面視において矩形であり、拡散板３０の外周の側面（前後左右の側面）は、導光板本体４の外周の側面（端面６、端面７、および左右の側面）と同一面内に配置されるか、それよりも外側に突出している。図７，８に示す拡散板３０は、前後方向において、凸条部外側面３７が導光板本体４の端面６および端面７よりも外側に突出し、左右方向において、導光板本体４の左右の側面と同一面内に配置されている。 The diffuser plate 30 is rectangular in plan view, and the outer peripheral side surfaces (front, rear, left and right side surfaces) of the diffuser plate 30 are the same as the outer peripheral side surfaces (end surface 6, end surface 7, and left and right side surfaces) of the light guide plate body 4. It is arranged inside or protrudes outside it. 7 and 8, in the front-rear direction, the ridge outer surface 37 protrudes outward from the end surface 6 and the end surface 7 of the light guide plate body 4, and the left and right side surfaces of the light guide plate body 4 in the left-right direction. Are arranged in the same plane.
　拡散板３０の外周の側面を、導光板本体４の外周の側面と同一面内に配置されるか、それよりも外側に突出させることで、照明装置１の平面視における外形が拡散板３０により規定される。なお、本実施の形態に係る照明装置１において、凸条部３４は、拡散板３０の周縁部のうち、前後のみに形成されているが、拡散板３０の左右側にも形成してもよい。拡散板３０の全周にわたって凸条部３４を形成することで、拡散板３０の剛性を高めることができる。 The outer peripheral side surface of the diffusing plate 30 is arranged in the same plane as the outer peripheral side surface of the light guide plate main body 4 or protrudes outward from the outer peripheral side surface. It is prescribed. In the lighting device 1 according to the present embodiment, the ridges 34 are formed only on the front and rear sides of the peripheral edge of the diffusion plate 30, but may also be formed on the left and right sides of the diffusion plate 30. . By forming the ridges 34 over the entire periphery of the diffusion plate 30, the rigidity of the diffusion plate 30 can be increased.
　凸条部３４の外側の側面である凸条部外側面３７は、空気に接する面である。また、凸条部３４の内側の側面である凸条部内側面３８も空気に接する面である。したがって、周縁光入射面３５から凸条部３４内に入射した光の一部は、凸条部外側面３７および凸条部内側面３８で全反射され、光出射面３３から出射することができる。凸条部外側面３７と凸条部内側面３８とは互いに平行な面であり、周縁光入射面３５は、凸条部外側面３７と凸条部内側面３８とに直交する面である。 The convex portion outer side surface 37 which is the outer side surface of the convex portion 34 is a surface in contact with air. In addition, the ridge inner side surface 38 which is the inner side surface of the ridge 34 is also a surface in contact with air. Accordingly, a part of the light incident from the peripheral light incident surface 35 into the protruding portion 34 is totally reflected by the protruding portion outer surface 37 and the protruding portion inner side surface 38 and can be emitted from the light emitting surface 33. The ridge outer surface 37 and the ridge inner surface 38 are parallel to each other, and the peripheral light incident surface 35 is a surface orthogonal to the ridge outer surface 37 and the ridge inner surface 38.
　凸条部３４の周縁光入射面３５は、ＬＥＤ３Ａ，３Ｂあるいは周縁部８Ａ，８Ｂから出射する光が遮光板３１により遮蔽される領域である遮光領域Ｂと、遮光板３１により遮蔽されることなく入射する領域である入射領域Ｃとを有する。すなわち、凸条部３４の周縁光入射面３５と、周縁部８Ａ，８Ｂとの間に遮光板３１を配置することにより、周縁部８Ａ，８Ｂから出射した光が周縁光入射面３５に入射する光量を制限することができる。 The peripheral light incident surface 35 of the ridge 34 is not shielded by the light shielding plate 31 and the light shielding region B, which is a region where the light emitted from the LEDs 3A, 3B or the peripheral portions 8A, 8B is shielded by the light shielding plate 31. And an incident region C that is an incident region. That is, by arranging the light shielding plate 31 between the peripheral light incident surface 35 of the ridge 34 and the peripheral portions 8A and 8B, the light emitted from the peripheral portions 8A and 8B enters the peripheral light incident surface 35. The amount of light can be limited.
　遮光領域Ｂは、ＬＥＤ３Ａ，３Ｂから出射された光を導光板２を介さずに直接拡散板３０に入射させない広さ（前後の幅寸法）を少なくとも有する。また、遮光領域Ｂの広さ（前後方向の幅寸法）と入射領域Ｃの広さ（前後方向の幅寸法）とは、周縁部８Ａ，８Ｂ（図１，３参照）から周縁光入射面３５に入射する光が光出射面３３から出射する際に、光出射面３３の全体の明るさが均一となるように設定される。周縁部８Ａ，８Ｂから周縁光入射面３５に入射した光は主に、光出射面３３の周縁部から出射することになる。光出射面３３の周縁部の明るさが、該周縁部よりも内側の明るさに近づくように、遮光領域Ｂの広さおよび入射領域Ｃの広さが設定される。 The light shielding region B has at least a width (front and rear width dimensions) that does not allow the light emitted from the LEDs 3A and 3B to directly enter the diffusion plate 30 without passing through the light guide plate 2. The width of the light-shielding region B (width dimension in the front-rear direction) and the width of the incident region C (width dimension in the front-rear direction) are determined from the peripheral portions 8A and 8B (see FIGS. 1 and 3) to the peripheral light incident surface 35. When the light incident on the light exits from the light exit surface 33, the entire brightness of the light exit surface 33 is set to be uniform. The light incident on the peripheral light incident surface 35 from the peripheral portions 8A and 8B is mainly emitted from the peripheral portion of the light emitting surface 33. The width of the light shielding region B and the width of the incident region C are set so that the brightness of the peripheral portion of the light emitting surface 33 approaches the brightness inside the peripheral portion.
　続いて、照明装置１において、ＬＥＤ３Ａ，３Ｂから出射された光が光出射面３３から出射するまでの光の経路について説明する。ＬＥＤ３Ａ，３Ｂから出射された光は、導光板２内を導光することで輝度の均一化が図られた状態で第１主平面８から出射する。 Subsequently, a description will be given of a light path until the light emitted from the LEDs 3 </ b> A and 3 </ b> B is emitted from the light emission surface 33 in the illumination device 1. The light emitted from the LEDs 3 </ b> A and 3 </ b> B is emitted from the first main plane 8 in a state where the brightness is uniformed by being guided through the light guide plate 2.
　第１主平面８から出射された光は、拡散板３０の光入射面３２および周縁光入射面３５に入射され、拡散板３０内を進行し光出射面３３から出射される。拡散板３０には光散乱粒子が含有されている。そのため、拡散板３０内に入射した光が拡散板３０内で散乱され、光出射面３３から出射する光の輝度分布の均一化を図ることができる。 The light emitted from the first main plane 8 is incident on the light incident surface 32 and the peripheral light incident surface 35 of the diffusion plate 30, travels through the diffusion plate 30, and is emitted from the light emission surface 33. The diffusion plate 30 contains light scattering particles. Therefore, the light incident on the diffusion plate 30 is scattered in the diffusion plate 30, and the luminance distribution of the light emitted from the light exit surface 33 can be made uniform.
　ＬＥＤ３Ａ，３Ｂから出射される光は、ＬＥＤ３Ａ，３Ｂに近い位置では明るく、遠くなるに従い暗くなる。しかしながら、照明装置１では、導光板本体４の端面６にＬＥＤ３Ａを備え、導光板本体４の端面７にＬＥＤ３Ｂを備え、相互に前後に向かって光が進行するので、前後からの光とが互いに補完しあうことで、導光板２の第１主平面８の輝度が均一化される。 The light emitted from the LEDs 3A and 3B is bright at a position close to the LEDs 3A and 3B, and becomes darker as the distance increases. However, in the lighting device 1, the LED 3A is provided on the end surface 6 of the light guide plate body 4, and the LED 3B is provided on the end surface 7 of the light guide plate body 4, and the light travels forward and backward. By complementing each other, the luminance of the first main plane 8 of the light guide plate 2 is made uniform.
　導光板２のＬＥＤ３Ａ，３Ｂに近い周縁部８Ａ，８Ｂには、遮光板３１が配置されている。遮光板３１により、ＬＥＤ３Ａ，３Ｂから直接あるいは周縁部８Ａ，８Ｂから凸条部３４へ入射する光が制限され、周縁光入射面３５の一部は遮光領域Ｂとなっている。つまり、ＬＥＤ３Ａ，３Ｂから出射され周縁光入射面３５に向かう光の一部は遮光領域Ｂすなわち遮光板３１より遮蔽される。 A light shielding plate 31 is disposed on the peripheral portions 8A and 8B of the light guide plate 2 near the LEDs 3A and 3B. The light shielding plate 31 restricts light that is incident directly on the LEDs 3A and 3B or from the peripheral edge portions 8A and 8B to the ridges 34, and a part of the peripheral light incident surface 35 is a light shielding region B. That is, part of the light emitted from the LEDs 3 </ b> A and 3 </ b> B toward the peripheral light incident surface 35 is shielded by the light shielding region B, that is, the light shielding plate 31.
　一方、入射領域Ｃでは、第１主平面８から凸条部３４の周縁光入射面３５に向けて出射された光の一部が入射される。凸条部３４の周縁光入射面３５から入射された光の一部は、凸条部３４の凸条部内側面３８と凸条部外側面３７とで全反射されながら、また、光散乱粒子で散乱されながら進み、拡散板３０の光出射面３３の主として凸条部３４の配置領域上方、すなわち光出射面３３のＬＥＤ３Ａ，３Ｂが配置される側の周縁部から出射される。すなわち、凸条部３４内に入射された光の一部は、凸条部外側面３７と凸条部内側面３８とで全反射されながら、また、光散乱粒子で散乱されながら進むことで、光出射面３３から拡散状態で出射される。凸条部３４に入射した光は主として凸条部３４の配置位置上方から出射する。 On the other hand, in the incident region C, a part of the light emitted from the first main plane 8 toward the peripheral light incident surface 35 of the ridge 34 is incident. A part of the light incident from the peripheral light incident surface 35 of the ridge portion 34 is totally reflected by the ridge portion inner side surface 38 and the ridge portion outer surface 37 of the ridge portion 34, and is also a light scattering particle. The light travels while being scattered, and is emitted mainly from the light exit surface 33 of the diffuser plate 30 above the region where the protrusions 34 are disposed, that is, from the peripheral portion of the light exit surface 33 on the side where the LEDs 3A and 3B are disposed. That is, a part of the light incident in the ridge 34 is totally reflected on the ridge outer surface 37 and the ridge inner surface 38 and is scattered while being scattered by the light scattering particles. The light is emitted from the emission surface 33 in a diffuse state. The light incident on the ridge 34 is emitted mainly from above the position where the ridge 34 is disposed.
　以上説明した照明装置１は、遮光板３１により遮光領域Ｂが形成されている。これにより、ＬＥＤ３Ａ，３Ｂの出射光が、拡散板３０に直接入射することを防止されている。また、導光板２に入射された光の一部は、導光板２内を光散乱粒子で散乱されながら導光され、第１主平面８から拡散光として出射され、拡散板３０に入射される。そして、第１主平面８から出射した光は、拡散板３０を透過し、この拡散板３０でさらに拡散された状態で光出射面３３から出射される。さらに、照明装置１は、拡散板３０のＬＥＤ３Ａ，３Ｂの配置位置側の周縁部に凸条部３４が形成されている。凸条部３４が設けられることで、凸条部外側面３７および凸条部内側面３８が形成される。そのため、導光板２の周縁部８Ａ，８Ｂから出射し凸条部３４の周縁光入射面３５に入射した光の一部は、凸条部３４の凸条部外側面３７と凸条部内側面３８とで全反射されながら、また、光散乱粒子で散乱されながら進み、拡散板３０の光出射面３３の周縁部から拡散光を出射させられる。 In the illumination device 1 described above, the light shielding region B is formed by the light shielding plate 31. This prevents the light emitted from the LEDs 3A and 3B from directly entering the diffusion plate 30. Further, part of the light incident on the light guide plate 2 is guided while being scattered by the light scattering particles in the light guide plate 2, emitted as diffused light from the first main plane 8, and incident on the diffuser plate 30. . The light emitted from the first main plane 8 passes through the diffusion plate 30 and is emitted from the light emission surface 33 in a state of being further diffused by the diffusion plate 30. Furthermore, the illuminating device 1 has a ridge 34 formed on the peripheral edge of the diffusion plate 30 on the side where the LEDs 3A and 3B are arranged. By providing the protruding line part 34, the protruding line part outer surface 37 and the protruding line part inner side surface 38 are formed. Therefore, part of the light emitted from the peripheral portions 8A and 8B of the light guide plate 2 and incident on the peripheral light incident surface 35 of the convex portion 34 is a convex portion outer side surface 37 and a convex portion inner side surface 38 of the convex portion 34. And diffused light is emitted from the peripheral edge of the light emitting surface 33 of the diffusion plate 30 while being totally reflected by the light scattering particles and scattered by the light scattering particles.
　つまり、遮光板３１で遮光領域Ｂを形成することで、ＬＥＤ３Ａ，３Ｂの出射光は拡散板３０に直接入射させられることなく導光板２に入射することができる。導光板２に入射した光の一部は、導光板２内を光散乱粒子で散乱されながら導光され、第１主平面８から拡散光として出射し、拡散板３０に入射される。これにより、ＬＥＤ３Ａ，３Ｂの出射光が拡散板３０に直接入射した場合にＬＥＤ３Ａ，３Ｂの部分が点光源のように見えてしまうことを防止しできる。 That is, by forming the light shielding region B with the light shielding plate 31, the light emitted from the LEDs 3 </ b> A and 3 </ b> B can be incident on the light guide plate 2 without being directly incident on the diffusion plate 30. A part of the light incident on the light guide plate 2 is guided while being scattered by the light scattering particles in the light guide plate 2, exits from the first main plane 8 as diffused light, and enters the diffuser plate 30. Thereby, when the emitted light of LED3A, 3B injects into the diffuser plate 30 directly, it can prevent that the part of LED3A, 3B looks like a point light source.
　また、拡散板３０に凸条部３４が設けられているため、周縁部８Ａ，８Ｂから出射した光は凸条部３４の周縁光入射面３５から凸条部３４内に導光され、凸条部３４の凸条部内側面３８と凸条部外側面３７とで全反射させながら、また、光散乱粒子で散乱され、拡散板３０の光出射面３３の周縁部から拡散光として出射させれる。これにより、遮光板３１を備える構成とした場合にも、光出射面３３の遮光板３１が備えられる側の周縁部に、遮光板３１により遮光され縁取りされたような暗部が生じることを防止できる。 In addition, since the ridge 34 is provided on the diffusion plate 30, the light emitted from the peripheral portions 8 </ b> A and 8 </ b> B is guided into the ridge 34 from the peripheral light incident surface 35 of the ridge 34, and The light is scattered by the light scattering particles while being totally reflected by the inner surface 38 and the outer surface 37 of the protruding portion of the portion 34, and is emitted as diffused light from the peripheral portion of the light emitting surface 33 of the diffusion plate 30. As a result, even when the light shielding plate 31 is provided, it is possible to prevent a dark portion that is shielded by the light shielding plate 31 from the edge of the light emitting surface 33 on the side where the light shielding plate 31 is provided. .
　したがって、照明装置１は、ＬＥＤ３Ａ，３Ｂが点光源に見えることによる見栄えが悪くなることを排除しながら、光出射面３３の周縁部が縁取りされたように暗くならずに周縁部を含めて光出射面３３の全体の明るさの均一化を図ることができる。 Therefore, the lighting device 1 does not darken the peripheral portion of the light emitting surface 33 as if the peripheral portion of the light emitting surface 33 is edged while eliminating the appearance that the LEDs 3A and 3B appear as point light sources. The overall brightness of the emission surface 33 can be made uniform.
　なお、凸条部３４の光の入射領域Ｃの大きさは、凸条部３４の幅寸法を大きくする、または小さくすることで調整可能である。つまり、拡散板３０の光出射面における中央部と周縁部の明るさの均一化は、導光板２から出射された光の凸条部３４への入射量を調整することで容易に行うことができる。 Note that the size of the light incident area C of the ridge 34 can be adjusted by increasing or decreasing the width of the ridge 34. That is, the brightness of the central portion and the peripheral portion of the light exit surface of the diffuser plate 30 can be easily made uniform by adjusting the amount of light emitted from the light guide plate 2 to the ridges 34. it can.
　本実施の形態における照明装置１において、遮光領域Ｂは、たとえば、周縁光入射面３５に遮光性を有するテープを貼着したり、あるいは、遮光性を有する塗料の塗布を施すことで形成することができる。 In the lighting device 1 according to the present embodiment, the light shielding region B is formed by, for example, attaching a light shielding tape to the peripheral light incident surface 35 or applying a light shielding coating. Can do.
　導光板２と周縁光入射面３５との間に遮光板３１を設けない構成としてもよい。かかる構成とした場合においても、周縁光入射面３５から凸条部３４内に入射した光が、凸条部３４内を。凸条部外側面３７と凸条部内側面３８とで全反射されながら、また、光散乱粒子で散乱されながら進むことで、光出射面３３から拡散状態で出射される。そのため、光出射面３３の周縁について輝度の低下が抑えられ、光出射面３３の全体の明るさの均一化を図ることができる。 The light shielding plate 31 may not be provided between the light guide plate 2 and the peripheral light incident surface 35. Even in such a configuration, the light that has entered the ridge 34 from the peripheral light incident surface 35 enters the ridge 34. The light is emitted from the light emitting surface 33 in a diffused state while being totally reflected by the protruding portion outer surface 37 and the protruding portion inner side surface 38 and being scattered by the light scattering particles. Therefore, a decrease in luminance is suppressed at the periphery of the light emitting surface 33, and the overall brightness of the light emitting surface 33 can be made uniform.
（第４の実施の形態）
　図９に示すように、導光板本体４は、点状光拡散部１０Ａ，１０Ｂおよび点状光拡散部１１を反射面５Ａに対向する第２主平面９に形成し、線状光拡散部１２Ａ，１２Ｂおよび線状光拡散部１３を光出射面となる第１主平面８に形成する構成としてもよい。 (Fourth embodiment)
As shown in FIG. 9, the light guide plate main body 4 is formed by forming the point light diffusing portions 10A and 10B and the point light diffusing portion 11 on the second main plane 9 facing the reflecting surface 5A, and the linear light diffusing portion 12A. , 12B and the linear light diffusion portion 13 may be formed on the first main plane 8 serving as a light emission surface.
　なお、図１０に示すように、上述の第３の実施の形態に示す拡散板３０を備えた照明装置１を複数並列させることで、大判のパネル型照明装置１００を構成することができる。 In addition, as shown in FIG. 10, the large-sized panel type illuminating device 100 can be comprised by paralleling the illuminating device 1 provided with the diffusion plate 30 shown in the above-mentioned 3rd Embodiment in parallel.
　図１０は、照明装置１を２個並列させたパネル型照明装置１００の１例を示す平面図である。図１０に示すように、パネル型照明装置１００は、各照明装置１を、各照明装置１の凸条部外側面３７同士を密接させて配置している。 FIG. 10 is a plan view showing an example of a panel-type lighting device 100 in which two lighting devices 1 are arranged in parallel. As shown in FIG. 10, in the panel illumination device 100, each illumination device 1 is arranged such that the protruding portion outer surfaces 37 of the illumination devices 1 are in close contact with each other.
　照明装置１は、前述したように、光出射面３３の周縁部が縁取りされたように暗くならず、周縁部を含めて輝度が均一化されている。したがって、２つの照明装置１を並列させたときにも、つなぎ目部分が縁取りされたようにならずに、見栄えのよい大判のパネル型照明装置１００を実現できる。 As described above, the illumination device 1 is not dark as if the peripheral portion of the light emitting surface 33 is trimmed, and the luminance is uniform including the peripheral portion. Therefore, even when the two lighting devices 1 are juxtaposed, the large-sized panel type lighting device 100 having a good appearance can be realized without the joint portion being trimmed.
　なお、パネル型照明装置１００としては、照明装置１の配列の仕方は限定されない。たとえば、照明装置１の配列数は３個以上でもよく、配列の方向も特に限定されない。 In addition, as the panel type illumination device 100, the arrangement of the illumination devices 1 is not limited. For example, the number of the lighting devices 1 may be three or more, and the direction of the arrangement is not particularly limited.
１　…　照明装置
２　…　導光板
３Ａ，３Ｂ　…　ＬＥＤ（光源）
５　…　反射板（反射手段）
６　…　端面（第１端面）
６Ａ，７Ａ　…　斜面
７　…　端面（第２端面）
８　…　第１主平面
８Ａ，８Ｂ　…　周縁部
９　…　第２主平面
１０Ａ，１０Ｂ　…　点状光拡散部（点状第１光拡散部，第１光拡散部）
１１　…　点状光拡散部（点状第２光拡散部，第２光拡散部）
１２Ａ，１２Ｂ　…　線状光拡散部（線状第１光拡散部，第１光拡散部）
１２ＡＡ，１２ＢＢ　…　溝
１３　…　線状光拡散部（線状第２光拡散部，第２光拡散部）
２０　…　ＬＥＤチップ
２１　…　反射板
３０　…　拡散板
３１　…　遮光板（光遮蔽部材）
３２　…　光入射面
３３　…　光出射面
３４　…　凸条部
３５　…　周縁光入射面
  DESCRIPTION OF SYMBOLS 1 ... Illuminating device 2 ... Light guide plate 3A, 3B ... LED (light source)
5 ... Reflector (reflecting means)
6 ... End face (first end face)
6A, 7A ... slope 7 ... end face (second end face)
8 ... 1st main plane 8A, 8B ... Peripheral part 9 ... 2nd main plane 10A, 10B ... Point-like light diffusion part (dot-like 1st light diffusion part, 1st light diffusion part)
11: Point light diffusing section (dot second light diffusing section, second light diffusing section)
12A, 12B ... linear light diffusion part (linear first light diffusion part, first light diffusion part)
12AA, 12BB ... groove 13 ... linear light diffusion part (linear second light diffusion part, second light diffusion part)
20 ... LED chip 21 ... Reflecting plate 30 ... Diffusing plate 31 ... Shading plate (light shielding member)
32... Light incident surface 33... Light emitting surface 34.

Claims (11)

  1. 　並列される複数の光源から出射される光が入射し、互いに対向して配置される第１端面および第２端面と、
    　前記各端面から入射した前記複数の光源からの光が出射する互いに対向して配置される第１主平面および第２主平面と、
    　前記第２主平面に対向して配置され、前記第２主平面から出射された前記光を前記第２主平面側に反射する反射手段と、
    　を有し、
    　前記各主平面には、前記並列される複数の光源の隣り合う光源の間に対応した領域に、前記各端面から対向する端面に向かうに従って幅が狭くなる第１光拡散部が形成され、
    　前記各主平面のうち、いずれか一方の主平面に形成される前記第１光拡散部は、多数の突起または穴の集合にて形成される点状第１光拡散部であり、他方の主平面に形成される前記第１光拡散部は、長さ方向が前記複数の光源の並列方向に平行な多数の凸条または溝の集合にて形成される線状第１光拡散部である、
    　ことを特徴とする導光板。     A first end surface and a second end surface on which light emitted from a plurality of light sources arranged in parallel is incident and disposed opposite to each other;
    A first main plane and a second main plane that are arranged opposite to each other and emit light from the plurality of light sources incident from the end faces;
    Reflecting means that is disposed to face the second main plane and reflects the light emitted from the second main plane to the second main plane side;
    Have
    Each main plane is formed with a first light diffusing portion whose width becomes narrower from each end face toward the opposite end face in a region corresponding to between adjacent light sources of the plurality of light sources arranged in parallel.
    The first light diffusing portion formed on one of the main planes is a point-like first light diffusing portion formed by a set of a large number of protrusions or holes, and the other main plane. The first light diffusing portion formed in a plane is a linear first light diffusing portion formed by a set of a plurality of ridges or grooves whose length direction is parallel to the parallel direction of the plurality of light sources.
    A light guide plate characterized by that.
  2. 　請求項１に記載の導光板において、
    　前記点状第１光拡散部は、前記第２主平面に形成され、前記線状第１光拡散部は、前記第１主平面に形成されている、
    　ことを特徴とする導光板。     The light guide plate according to claim 1,
    The point-like first light diffusion part is formed on the second main plane, and the linear first light diffusion part is formed on the first main plane.
    A light guide plate characterized by that.
  3. 　請求項１または２に記載の導光板において、
    　前記点状第１光拡散部および前記線状第１光拡散部は、前記光源の照射角の７０％よりも外側の範囲に形成されている、
    　ことを特徴とする導光板。     The light guide plate according to claim 1 or 2,
    The point-like first light diffusion part and the linear first light diffusion part are formed in a range outside 70% of the irradiation angle of the light source,
    A light guide plate characterized by that.
  4. 　請求項１から３のいずれか１項に記載の導光板において、
    　前記各主平面には、前記第１端面側に形成される前記第１光拡散部と前記第２端面側に形成される前記第１光拡散部との間に第２光拡散部が形成され、
    　前記第１拡散部として前記点状第１光拡散部が形成される側の前記主平面に形成される前記第２光拡散部は、多数の突起または穴の集合にて形成される点状第２光拡散部であり、前記第１拡散部として前記線状第１光拡散部が形成される側の前記主平面に形成される前記第２光拡散部は、長さ方向が前記光源の並列方向に平行な多数の凸条または溝の集合にて形成される線状第２光拡散部である、
    　ことを特徴とする導光板。     The light guide plate according to any one of claims 1 to 3,
    In each main plane, a second light diffusion portion is formed between the first light diffusion portion formed on the first end surface side and the first light diffusion portion formed on the second end surface side. ,
    The second light diffusing portion formed on the main plane on the side where the dotted first light diffusing portion is formed as the first diffusing portion is formed by a plurality of projections or holes. The second light diffusing unit formed on the main plane on the side where the linear first light diffusing unit is formed as the first diffusing unit is arranged in parallel with the light source in the length direction. A linear second light diffusing portion formed by a set of a large number of ridges or grooves parallel to the direction,
    A light guide plate characterized by that.
  5. 　前記請求項４に記載の導光板において、
    　前記点状第２光拡散部は、前記光源の照明光軸からの距離が遠いほど形成密度が高い、
    　ことを特徴とする導光板。     The light guide plate according to claim 4,
    The dotted second light diffusing portion has a higher formation density as the distance from the illumination optical axis of the light source is longer.
    A light guide plate characterized by that.
  6. 　請求項１から５のいずれか１項に記載の導光板において、
    　前記導光板は、前記第１端面と前記第２端面との間隔が３０ｍｍ以上８０ｍｍ以下である、
    　ことを特徴とする導光板。     In the light-guide plate of any one of Claim 1 to 5,
    The light guide plate has an interval between the first end surface and the second end surface of 30 mm or more and 80 mm or less.
    A light guide plate characterized by that.
  7. 　請求項１から６のいずれか１項に記載の導光板において、
    　前記光源は、ＬＥＤチップをカップ状の反射板内に配置したＬＥＤであり、
    　前記導光板の前記第１主平面と前記第２主平面との間隔は、前記反射板の開口径以上であり前記開口径の３倍以下である、
    　ことを特徴とする導光板。     In the light-guide plate of any one of Claim 1 to 6,
    The light source is an LED in which an LED chip is arranged in a cup-shaped reflector,
    The distance between the first main plane and the second main plane of the light guide plate is not less than the opening diameter of the reflecting plate and not more than three times the opening diameter.
    A light guide plate characterized by that.
  8. 　請求項１から７のいずれか１項に記載の導光板において、
    　前記第１端面と前記第２端面とは、前記領域に対応した部分が前記第２主平面から前記第１主平面に向かって互いに間隔が広くなる斜面に形成されている、
    　ことを特徴とする導光板。     The light guide plate according to any one of claims 1 to 7,
    The first end surface and the second end surface are formed on inclined surfaces in which portions corresponding to the region are spaced apart from each other from the second main plane toward the first main plane.
    A light guide plate characterized by that.
  9. 　請求項１から８のいずれか１項に記載の導光板において、
    　前記第１主平面から出射した光が入射する光入射面と、この光入射面から入射した光が出射する光出射面とを有する拡散板が前記第１主平面の側に配置され、
    　前記拡散板は、前記第１主平面側に突出し、前記導光板の前記第１主平面の周縁部のうち少なくとも前記各端面側の周縁部に対向する位置に設けられ、前記各周縁部から出射する光が入射する光入射面である周縁光入射面を有する凸条部を有する、
    　ことを特徴とする導光板。     The light guide plate according to any one of claims 1 to 8,
    A diffusion plate having a light incident surface on which light emitted from the first main plane is incident and a light emission surface from which light incident from the light incident surface is emitted is disposed on the first main plane side,
    The diffusion plate protrudes to the first main plane side and is provided at a position facing at least a peripheral portion on each end face side of the peripheral portion of the first main plane of the light guide plate, and is emitted from each peripheral portion. Having a ridge having a peripheral light incident surface that is a light incident surface on which light is incident,
    A light guide plate characterized by that.
  10. 　請求項９に記載の導光板において、
    　前記各周縁部と前記凸条部の周縁光入射面との間には、前記周縁部から出射した光が前記周縁光入射面に入射する光量を制限する光遮蔽部が備えられている、
    ことを特徴とする導光板。     The light guide plate according to claim 9,
    Between each of the peripheral portions and the peripheral light incident surface of the ridge portion, there is provided a light shielding portion that restricts the amount of light emitted from the peripheral portion that enters the peripheral light incident surface.
    A light guide plate characterized by that.
  11. 　請求項１から１０のいずれか１項に記載の導光板と、
    　前記導光板の前記端面に光を入射する光源と、
    　を有することを特徴とする照明装置。
          The light guide plate according to any one of claims 1 to 10,
    A light source that makes light incident on the end face of the light guide plate;
    A lighting device comprising:
PCT/JP2015/053764 2014-02-12 2015-02-12 Light guide plate, and lighting device WO2015122434A1 (en)

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JP2004145035A (en) * 2002-10-25 2004-05-20 Sanyo Electric Co Ltd Surface light source device and method for manufacturing light transmission plate used therein
JP2004296300A (en) * 2003-03-27 2004-10-21 Fujitsu Ltd Double-faced light emitting source
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