JP5842117B2 - Lighting device - Google Patents

Description

  The present invention relates to an illuminating device including a light emitting element such as an LED (Light Emitting Diode) as a light source, and more particularly to a technique for reducing luminance unevenness in an illuminating device that emits light using a light guide plate.

  As an example of an illumination device that emits light using a light guide plate, there is an edge light illumination device 800 as shown in FIG. In the illuminating device 800, a plurality of light emitting elements 822 are annularly arranged on the outer periphery of the light guide plate 840 with each main emission direction facing the light guide plate 840. The light emitted from the light emitting element 822 enters the light guide plate 840 from the incident surface 840c which is the outer peripheral surface of the light guide plate 840, and is uniformly emitted from the light output surface 840a which is the front side surface of the light guide plate 840. . A frame member 870 is attached to the outer peripheral edge of the light guide plate 840 so as to cover the light emitting element 822, and the frame member 870 protects the light emitting element 822 and improves the design of the lighting device 800. (Patent Document 1).

  However, if the frame member 870 is attached to the outer peripheral edge of the light guide plate 840, the light emitted from the outer peripheral edge of the light guide plate 840 is blocked by the frame member 870. Have difficulty.

  As another example of an illumination device that emits light using a light guide plate, there is a direct illumination device 900 as shown in FIG. In the lighting device 900, a plurality of light emitting elements 922 are arranged in an annular shape on the back side of the light guide plate 940 with the main emission direction of each light emitting element 922 facing the light guide plate 940. The light emitted from the light emitting element 922 enters the annular portion 941 from the incident surface 944b formed on the back side of the annular portion 941 of the light guide plate 940, and is reflected by the reflecting surface 941a which is the surface on the front side of the annular portion 941. Then, the light is guided into the inner ring portion 942 and the outer ring portion 943 of the light guide plate 940. Then, light is emitted uniformly from the light emitting surfaces 942a and 943a which are the front side surfaces of the ring inner portion 942 and the ring outer portion 943.

  When the light emitting element 922 is disposed on the back side of the light guide plate 940 as in the lighting device 900, it is not necessary to attach a frame material to the outer peripheral edge of the light guide plate 940, and the light is emitted from the outer peripheral edge of the light guide plate 940 by the frame material. Therefore, the front side of the lighting device 900 can emit light entirely.

JP 2012-84316 A JP 2012-104476 A

  However, in a configuration such as the lighting device 900, a shadow region in which almost no light is emitted is generated on the reflection surface 941a of the annular portion 941 of the light guide plate 940. Therefore, the shadow region causes uneven luminance of the lighting device 900. Become. More specifically, the reflecting surface 941a of the annular portion 941 is formed so as to substantially totally reflect light in order to efficiently guide light to the inner ring portion 942 and the outer ring portion 943, and from the reflecting surface 941a to the back side. Except for the region where the light emitting element 922 exists, light is hardly emitted to the front side. For this reason, a region other than the region where the light emitting element 922 exists on the reflection surface 941a is a shadow region, and luminance unevenness occurs due to the shadow region.

  In view of the above-described problems, an object of the present invention is to provide an illumination device that can realize front side full-surface light emission and has less luminance unevenness.

In order to achieve the above object, a lighting device according to an aspect of the present invention includes a plurality of light emitting elements arranged in an annular shape on the back side of a light guide plate with each main emission direction facing the light guide plate , and A reflecting member having a light reflecting surface is a lighting device that is disposed in proximity to the light guide plate in a state where the light reflecting surface and a part of the back side surface of the light guide plate are opposed to each other, and the light guide plate includes: An annular portion formed in an annular shape along an element row composed of the plurality of light emitting elements, and an annular inner portion formed continuously with the annular portion on the inner side of the annular portion ; The plurality of light emitting elements are arranged on the back side of the inner side of the ring and a part of the back side of the annular part so as to avoid an element row composed of the plurality of light emitting elements, and the plurality of light emitting elements are accommodated by the reflecting member. An annular groove is defined, and the groove is Wider towards the groove width of the portion corresponding to the gap between the light emitting elements adjacent than the groove width of the portion corresponding to the element, the annular portion is emitted from the light emitting element a said element array portion facing the An element row facing portion having an incident surface on which light is incident, and a portion positioned on the inner ring side of the element row facing portion and reflecting light incident from the incident surface toward the inner ring portion An inner reflection portion having a reflection surface, and the reflection surface includes a ring-shaped first light scattering region that is subjected to a light scattering process along the element array facing portion, and the ring more than the first light scattering region. A second light scattering region that is a region on the inner side and has been subjected to a light scattering process different from the first light scattering region so as to emit more light than the first light scattering region. It is characterized by providing.

  In the lighting device according to one embodiment of the present invention, a plurality of light-emitting elements are annularly arranged on the back side of the light guide plate. Therefore, it is not necessary to attach a frame material to the outer periphery of the light guide plate in order to cover a plurality of light emitting elements, and the light emitted from the outer peripheral edge of the light guide plate is not blocked by the frame material. It is possible.

  In the lighting device according to one embodiment of the present invention, a light-scattering process is performed on the reflective surface of the reflective portion, and thus a shadow region is unlikely to occur in the annular portion. In addition, the reflection surface of the reflection portion has an annular first light scattering region that has been subjected to light scattering processing, and the first light scattering region so that more light is emitted than the first light scattering region. Since the second light scattering portion subjected to the light scattering treatment in a different mode is provided, a difference in luminance between a portion close to the light emitting element and a portion far from the light emitting element hardly occurs in the reflection portion. Therefore, the luminance unevenness is reduced as compared with the conventional lighting device.

The figure explaining the aspect of the attachment to the ceiling board of the illuminating device which concerns on 1st Embodiment. The perspective view which shows the illuminating device which concerns on 1st Embodiment. The disassembled perspective view which shows the illuminating device which concerns on 1st Embodiment. Sectional drawing which shows the illuminating device which concerns on 1st Embodiment. Enlarged sectional view of the portion surrounded by the two-dot chain line shown in FIG. It is a top view which shows the reflective member which concerns on 1st Embodiment, Comprising: (a) is the figure seen from the front side, (b) is the figure seen from the back side It is a top view which shows the light-guide plate which concerns on 1st Embodiment, Comprising: (a) is the figure seen from the front side, (b) is the figure seen from the back side The figure for demonstrating the brightness nonuniformity which arises with the conventional illuminating device. Schematic diagram for explaining luminance unevenness generated in a conventional lighting device Schematic diagram for explaining the path of light reflected from the device mounting surface of the substrate Schematic diagram for explaining the luminance unevenness reducing effect by the reflecting member Schematic diagram for explaining the path of light incident directly from the light emitting element into the light guide plate Schematic diagram for explaining the effect of reducing luminance unevenness by the light guide plate The figure for demonstrating the brightness nonuniformity reduction effect by the combination of a light-guide plate and a reflective member Schematic diagram for explaining the effect of reducing luminance unevenness due to the combination of the light guide plate and the reflecting member The disassembled perspective view which shows the illuminating device which concerns on 2nd Embodiment. Sectional drawing which shows the illuminating device which concerns on 2nd Embodiment. FIG. 17 is an enlarged cross-sectional view of a portion surrounded by a two-dot chain line Sectional drawing for demonstrating the light-guide plate and reflection member which concern on a modification Plan view showing a conventional edge light type illumination device Sectional view showing a conventional direct lighting system

  Hereinafter, a lighting device according to one embodiment of the present invention will be described with reference to the drawings. In addition, the scale of the member in each drawing differs from an actual thing. In the present application, the sign “˜” used to indicate a numerical range includes numerical values at both ends.

<First Embodiment>
(overall structure)
FIG. 1 is a diagram illustrating an aspect of attachment of the lighting device according to the first embodiment to a ceiling board. As shown in FIG. 1, a lighting device 1 according to an aspect of the present invention is a downlight that is attached so as to be embedded in a ceiling plate 2, for example. The lighting device 1 according to the present invention is not limited to a downlight, and may be a building lighting device other than a downlight such as a ceiling light, or an illumination other than a building lighting device such as a backlight. It may be a device.

  The lighting device 1 is configured such that a part of the case 10 is fitted into a through-hole 2 a provided in the ceiling plate 2, and the leaf spring-like latching member 3 attached to the case 10 is latched to the ceiling back surface 2 b of the ceiling plate 2. Is attached to the ceiling board 2. The latch member 3 is not limited to a leaf spring shape. Moreover, the attachment method to the ceiling board 2 of the illuminating device 1 is not limited to the thing by the latching using the latching member 3, You may attach by screwing or adhesion | attachment.

  A circuit unit 4 for lighting the lighting device 1 is disposed on the ceiling back surface 2 b of the ceiling plate 2, and the lighting device 1 is electrically connected to the circuit unit 4 via a power line 23. The circuit unit 4 is electrically connected to an external commercial AC power supply (not shown), and supplies a current input from the commercial AC power supply to the lighting device 1. In the present embodiment, the circuit unit 4 is required separately from the lighting device 1, but the lighting device according to the present invention may be a lighting device incorporating the circuit unit 4.

  FIG. 2 is a perspective view showing the lighting apparatus according to the first embodiment. FIG. 3 is an exploded perspective view showing the illumination device according to the first embodiment. FIG. 4 is a cross-sectional view showing the illumination device according to the first embodiment. FIG. 5 is an enlarged cross-sectional view of a portion surrounded by a two-dot chain line shown in FIG. As shown in FIGS. 2 to 5, the lighting device 1 includes, for example, a case 10, a light emitting module 20, a reflecting member 30, a light guide plate 40, a diffusion cover 50, and the like.

(Case)
As shown in FIG. 3, the case 10 is, for example, an aluminum die-cast dish-shaped body having a bottomed cylindrical main body 11 and an annular plate extending from the opening of the main body 11. And the collar portion 12.

  The main body 11 has a disk-shaped bottom plate portion 13 and a cylindrical side wall portion 14 extending to the outer peripheral edge of the bottom plate portion 13. As shown in FIG. The light emitting module 20, the reflecting member 30, and a part of the light guide plate 40 are accommodated. Returning to FIG. 3, a through hole 15 through which the power supply line 23 is inserted is formed in the side wall portion 14 of the main body 11.

  The flange portion 12 includes an annular plate-like main body portion 16 that is in contact with the ceiling plate 2 and a flange portion 17 that extends to the outer peripheral edge of the main body portion 16, as shown in FIG. In a state where the side wall 52 of the diffusion cover 50 is externally fitted to the flange portion 17, the case 10 and the diffusion cover 50 are fixed by, for example, adhesion.

(Light emitting module)
Returning to FIG. 3, the light emitting module 20 includes an annular plate-shaped substrate 21 and a plurality of light emitting elements 22 mounted on an element mounting surface 21 a which is one main surface of the substrate 21, and a light guide plate 40 on the back side. The light emitting elements 22 are arranged in an annular shape with a space between the light emitting elements adjacent to the element mounting surface 21a of the substrate 21 in a state where the main emission direction is directed to the light guide plate 40.

  The substrate 21 has, for example, a two-layer structure of an insulating layer made of a ceramic substrate or a heat conductive resin and a metal layer made of an aluminum plate or the like. A wiring pattern (not shown) is formed on the substrate 21, and each light emitting element 22 is electrically connected to the power supply line 23 through the wiring pattern and the connector 24. The element mounting surface 21a of the substrate 21 is a reflecting surface for efficiently reflecting light toward the light guide plate 40 side.

  The light emitting element 22 is, for example, an LED, and is mounted face up on the element mounting surface 21a of the substrate 21 using a COB (Chip on Board) technique. The light emitting element according to the present invention may be, for example, an LD (laser diode) or an EL element (electric luminescence element). The light emitting element according to the present invention may be a SMD (Surface Mount Device) type mounted on a substrate.

(Reflective member)
The reflection member 30 includes a circular plate-like inner reflection member 30a and an annular plate-like outer reflection member 30b disposed so as to surround the outer periphery of the inner reflection member 30a, as shown in FIG. The light guide plate 40 is disposed close to the light guide plate 40 on the back side. Specifically, the inner reflection member 30a is disposed on the back side of the ring inner side portion 42 of the light guide plate 40, and the outer reflection member 30b is disposed on the back side of the ring outer side portion 43 of the light guide plate 40, and is reflected. The entire member 30 is disposed on the back side of the light guide plate 40 so as to avoid the light emitting element 22. In other words, the reflecting member 30 accommodates an annular element array composed of a plurality of light emitting elements 22 when viewed from the direction orthogonal to the back side surfaces (the back side surface 42b and the back side surface 43b) of the light guide plate 40. It is arranged in a region that does not overlap with the annular element housing groove (groove portion) 60. In addition, in this application, the illumination direction side of the illuminating device 1 is a front side, and the opposite side of a front side is a back side. 2 to 5, the upper side of the paper is the front side, and the lower side of the paper is the back side.

  The outer diameter of the outer reflecting member 30 b is substantially the same as the inner diameter of the main body 11 of the case 10, and the positioning of the outer reflecting member 30 b is completed only by housing the outer reflecting member 30 b in the main body 11. As materials for the inner reflecting member 30a and the outer reflecting member 30b, materials having high reflectivity such as highly reflective polycarbonate resin, highly reflective nylon resin, highly reflective polybutylene terephthalate resin, and highly reflective foamed resin are optimal.

  As shown in FIG. 5, the surface on the front side of the inner reflecting member 30a is composed of a first light reflecting surface 31a and a second light reflecting surface 32a. The first light reflecting surface 31 a faces the back surface 42 b of the ring inner portion 42 of the light guide plate 40 and plays a role of reflecting light leaking from the ring inner portion 42 to the back side and returning it to the ring inner portion 42. The second light reflecting surface 32a faces the surface 46b on the back side of the second light scattering portion 46 of the annular portion 41 of the light guide plate 40, and reflects the light leaking from the second light scattering portion 46 to the back side. It plays the role of returning to the light scattering portion 46.

  The first light reflecting surface 31 a is in surface contact with the back surface 42 b of the ring inner portion 42, and the second light reflecting surface 32 a is in surface contact with the back surface 46 b of the second light scattering portion 46. Because of the surface contact, light can be efficiently returned to the light guide plate 40, and positioning of the inner reflection member 30a and the light guide plate 40 can be performed with high accuracy.

  The lighting device according to the present invention is not necessarily in surface contact, and there may be a gap between the first light reflecting surface 31a and the back surface 42b of the ring inner portion 42. Further, a gap may be formed between the second light reflecting surface 32 a and the back surface 46 b of the second light scattering portion 46.

  The surface on the front side of the outer reflecting member 30b is composed of a first light reflecting surface 31b and a second light reflecting surface 32b. The first light reflecting surface 31 b faces the back surface 43 b of the outer ring portion 43 of the light guide plate 40, and plays a role of reflecting light leaking from the outer ring portion 43 to the back side and returning it to the outer ring portion 43. The second light reflecting surface 32b is opposed to the back surface 48b of the fourth light scattering portion 48 of the annular portion 41 of the light guide plate 40, and reflects the light leaking from the fourth light scattering portion 48 to the back side. It plays the role of returning to the light scattering portion 48.

  The first light reflection surface 31 b is in surface contact with the back surface 43 b of the outer ring portion 43, and the second light reflection surface 32 b is in surface contact with the back surface 48 b of the fourth light scattering portion 48. Because of the surface contact, light can be efficiently returned to the light guide plate 40, and the positioning of the outer reflective member 30b and the light guide plate 40 can be performed with high accuracy. The lighting device according to the present invention is not necessarily in surface contact, and there may be a gap between the first light reflecting surface 31 b and the back surface 43 b of the outer ring portion 43. Further, a gap may be formed between the second light reflecting surface 32 b and the back surface 48 b of the fourth light scattering portion 48.

  As shown in FIG. 4, the inner reflecting member 30 a and the outer reflecting member 30 b are separated from each other on the back side of the light guide plate 40 by an outer peripheral surface 33 a of the inner reflecting member 30 a and an inner peripheral surface 33 b of the outer reflecting member 30 b. They are arranged facing each other. Thereby, the annular element accommodating groove 60 in which the light emitting element 22 is accommodated is defined by the inner reflecting member 30a and the outer reflecting member 30b. On the back side of the annular portion 41 of the light guide plate 40, a portion where the inner reflecting member 30 a and the outer reflecting member 30 b are not present is the element housing groove 60.

  The inner peripheral surface of the element receiving groove 60 is configured by the outer peripheral surface 33a of the inner reflecting member 30a, the outer peripheral surface of the element receiving groove 60 is configured by the inner peripheral surface 33b of the outer reflecting member 30b, and the bottom surface of the element receiving groove 60 is It is composed of an element mounting surface 21 a of the substrate 21. As shown in FIG. 5, the angle θ1 formed by the outer peripheral surface 33a of the inner reflecting member 30a and the element mounting surface 21a of the substrate 21 is an acute angle. Further, the angle θ2 formed by the inner peripheral surface 33b of the outer reflecting member 30b and the element mounting surface 21a of the substrate 21 is also an acute angle. And the outer peripheral surface 33a of the inner side reflection member 30a and the inner peripheral surface 33b of the outer side reflection member 30b are light reflection surfaces, respectively.

  6A and 6B are plan views showing the reflecting member according to the first embodiment, wherein FIG. 6A is a view seen from the front side, and FIG. 6B is a view seen from the back side. In FIG. 6, the arrangement position of the light emitting element with respect to the reflecting member is indicated by a two-dot chain line. The center of the reflecting member 30 is indicated by the symbol O.

  As shown in FIG. 6, the element receiving groove 60 has a groove width (adjacent to a portion where the light emitting element 22 is not present) than a groove width where the light emitting element 22 is present (a groove width corresponding to the light emitting element 22). The groove width of the portion corresponding to the gap between the matching light emitting elements 22 is wider. Here, the groove width of the element housing groove 60 is a distance between the outer peripheral surface 33a of the inner reflecting member 30a and the inner peripheral surface 33b of the outer reflecting member 30b, and is a distance in the radial direction of the reflecting member 30. .

  The groove width of the element receiving groove 60 will be described in more detail. As shown in FIG. 5, the groove width of the element receiving groove 60 increases for a while from the front side to the back side. As shown in FIG. 6A, in the element receiving groove 60, the groove width W2 at the portion where the light emitting element 22 does not exist is larger than the groove width W1 at the portion where the light emitting element 22 exists even in the front side opening. As shown in FIG. 6B, the groove width W4 in the portion where the light emitting element 22 does not exist is wider than the groove width W3 in the portion where the light emitting element 22 exists in the back side opening as well. Yes.

(Light guide plate)
As shown in FIG. 3, the light guide plate 40 has a circular plate shape, and has an annular portion 41 formed in an annular shape along the element row composed of the light emitting elements 22, and an annular portion 41 inside the annular portion 41. A disc-shaped annular inner portion 42 formed continuously with the annular portion 41, and an annular annular outer portion 43 formed continuously with the annular portion 41 outside the annular portion 41. Three of them, the annular part 41, the ring inner part 42 and the ring outer part 43, are integrally formed. As the material of the light guide plate 40, a material having good light guide properties such as acrylic resin, polycarbonate resin, polystyrene resin, and glass is optimal.

  The annular portion 41 includes an element array facing portion 44, a first light scattering portion 45, a second light scattering portion 46, a third light scattering portion 47, and a fourth light scattering portion 48. The element array facing portion 44 has an annular shape facing the element array composed of the plurality of light emitting elements 22. The first light scattering portion 45 is in an annular shape along the element row facing portion 44 located inside the ring of the element row facing portion 44. The second light scattering portion 46 is in an annular shape along the first light scattering portion 45 located inside the ring of the first light scattering portion 45. The first light scattering portion 45 and the second light scattering portion 46 constitute an inner reflection portion. The third light scattering portion 47 has an annular shape that is located outside the element array facing portion 44 and is located along the element array facing portion 44. The fourth light scattering portion 48 has an annular shape along the third light scattering portion 47 located outside the ring of the third light scattering portion 47. The third light scattering portion 47 and the second light scattering portion 48 constitute an outer reflection portion.

  4 and 5, the range indicated by reference sign W41 is the annular part 41, the range indicated by reference sign W42 is the ring inner part 42, and the range indicated by reference sign W43 is the ring inner part 42. The outer peripheral edge portion of the outer ring portion 43 is positioned by being sandwiched between the main body portion 16 and the outer peripheral edge portion 51 a of the diffusion cover 50 while being placed on the main body portion 16 of the flange portion 12 of the case 10. ing. In FIG. 5, the range indicated by the symbol W44 is the element array facing portion 44, the range indicated by the symbol W45 is the first light scattering portion 45, the range indicated by the symbol W46 is the second light scattering portion 46, and the symbol W47. The range indicated by is the third light scattering portion 47, and the range indicated by the symbol W48 is the fourth light scattering portion.

  As shown in FIG. 5, the front surface of the light guide plate 40 includes a front surface 41 a of the annular portion 41, a front surface 42 a of the annular inner portion 42, and a front surface 43 a of the annular outer portion 43. The The front side surface 41a of the annular portion 41 includes a front side surface 44a of the element array facing portion 44, a front side surface of the inner reflection portion, and a front side surface of the outer reflection portion. The front-side surface of the inner reflection portion is a reflection surface, and the first light-scattering region 45 a that is the front-side surface of the first light-scattering portion 45 and the second light that is the front-side surface of the second light-scattering portion 46. And a scattering region 46a. The surface on the front side of the outer reflection portion is also a reflection surface, and the third light scattering region 47a that is the surface on the front side of the third light scattering portion 47 and the fourth light that is the surface on the front side of the fourth light scattering portion 48. And a scattering region 48a.

  The back surface of the light guide plate 40 includes a back surface 41 b of the annular portion 41, a back surface 42 b of the annular inner portion 42, and a reverse surface 43 b of the annular outer portion 43. And the back side surface 41b of the annular portion 41 includes a back side surface 44b of the element array facing portion 44, a back side surface 45b of the first light scattering portion 45, a back side surface 46b of the second light scattering portion 46, The back surface 47 b of the third light scattering portion 47 and the back surface 48 b of the fourth light scattering portion 48 are configured.

  In addition, the light-guide plate which concerns on this invention is not limited to circular plate shape, but is arbitrary. For example, a polygonal plate shape such as a quadrangular plate shape, a hexagonal plate shape, an octagonal plate shape, or the like may be used. In addition, each shape of the annular part, the inner part of the ring, the outer part of the ring, the element array facing part, the first light scattering part, the second light scattering part, the third light scattering part, and the fourth light scattering part is also the light guide plate. It is optional depending on the shape. Furthermore, the arrangement of the light emitting elements and the shape of the substrate are arbitrary depending on the shape of the light guide plate.

  The front surface 41 a of the annular portion 41 is a reflection surface for reflecting the light of the light emitting element 22 incident on the annular portion 41 from the back side toward the annular inner portion 42 or the annular outer portion 43. As shown in FIGS. 4 and 5, in the longitudinal section of the light guide plate 40 (cross section cut through a virtual plane that passes through the center of the front side surface of the light guide plate 40 and is orthogonal to the front side surface of the light guide plate 40). The shape of the surface 41a on the front side of the annular portion 41 is a substantially V-shape folded back so that the center protrudes to the back side. The folded portion has an R shape that swells on the back side. In order to reflect light efficiently toward the inner ring portion 42 and the outer ring portion 43, both sides of the folded portion are each formed in a substantially arc shape that swells to the front side.

  The front surface 41a of the annular portion 41 is subjected to light scattering processing. Specifically, the first light scattering region 45a, the second light scattering region 46a, the third light scattering region 47a, and the fourth light scattering region 48a are provided with recesses 45c, 46c, 47c, and 48c as a light scattering process. ing. Since the light scattering process is performed, the light incident on the front side surface 41a from the inside of the annular portion 41 is not totally reflected, but a part thereof is scattered by the recesses 45c, 46c, 47c, 48c, The light is emitted to the outside of the light guide plate 40. Note that no concave portion is provided on the front surface 44 a of the element array facing portion 44.

  In the present embodiment, the recesses 45c, 46c, 47c, and 48c are substantially hemispherical in shape and all have the same size. Note that the shape and size of the recess according to the present invention are arbitrary, and any shape can be used as long as the light scattering effect can be obtained. The shape may be, for example, a substantially conical shape or a substantially truncated cone shape.

  7A and 7B are plan views showing the light guide plate according to the first embodiment, where FIG. 7A is a view seen from the front side, and FIG. 7B is a view seen from the back side. As shown in FIG. 7A, when the first light scattering portion 45 and the second light scattering portion 46 are compared, the first light scattering region 45a and the second light scattering region 46a have different modes of light scattering processing. Is given. Specifically, the number of the concave portions 45c and 46c per unit area is larger in the second light scattering region 46a than in the first light scattering region 45a. Therefore, more light is emitted from the second light scattering portion 46 than the first light scattering portion 45.

  Further, when the third light scattering portion 47 and the fourth light scattering portion 48 are compared, the third light scattering region 47a and the fourth light scattering region 48a are subjected to different modes of light scattering processing. Specifically, the number of the concave portions 47c and 48c per unit area is larger in the fourth light scattering region 48a than in the third light scattering region 47a. Therefore, more light is emitted from the fourth light scattering portion 48 than from the third light scattering portion 47.

  In the present embodiment, the first light scattering portion 45 and the third light scattering portion 47 are subjected to the same light scattering process, and the second light scattering portion 46 and the fourth light scattering portion 48 are also applied. The same mode of light scattering treatment is applied. That is, the first light scattering region 45a and the third light scattering region 47a have the same number of recesses 45c and 47c per unit area. The second light scattering region 46a and the fourth light scattering region 48a have the same number of recesses 46c, 48c per unit area.

  Returning to FIG. 5, a part of the back surface 41 b of the annular portion 41 is an incident surface on which light of the light emitting element 22 is incident. The back surface 44b of the element array facing portion 44 corresponds to the incident surface. The back surface 44 b of the element array facing portion 44 has an annular shape facing the element array composed of the plurality of light emitting elements 22. Further, the entire surface 41 b on the back side of the annular portion 41 also functions as an incident surface for the light reflected by the element mounting surface 21 a of the substrate 21 to enter the annular portion 41 in the element accommodating groove 60.

  The surface 42a on the front side of the ring inner portion 42 is a light emitting surface from which a part of the light incident on the ring inner portion 42 is emitted. The surface 43 a on the front side of the outer ring portion 43 is a light emitting surface from which a part of the light incident on the outer ring portion 43 is emitted.

  The back surface 42b of the ring inner portion 42 is provided with a recess 42c as a light scattering process. Therefore, the light incident on the recess 42c in the ring inner portion 42 becomes scattered light and is emitted from the front surface 42a. As shown in FIG. 7B, the number of the concave portions 42c increases per unit area as the distance from the center of the back surface 42b of the ring inner portion 42 increases, so that the entire surface 42a is uniformly distributed. Light is emitted.

  A recess 43c is provided on the back surface 43b of the outer ring portion 43 as a light scattering process. Therefore, the light incident on the concave portion 43c in the outer ring portion 43 becomes scattered light and is emitted from the front surface 43a. The number of the recesses 43c per unit area increases toward the outer peripheral edge of the back surface 43b of the outer ring portion 43, so that light is uniformly emitted from the entire front surface 43a. Yes. On the other hand, as shown in FIG. 3, the outer peripheral surface 43 d of the outer ring portion 43 is processed so that light does not leak from the outer peripheral surface 43 d to the outside of the light guide plate 40. The light that travels in the outer ring portion 43 and reaches the outer peripheral surface 43d is reflected by the outer peripheral surface 43d, and thus returns to the annular portion 41 without returning from the outer ring portion 43.

  In addition, the light scattering process performed on the ring inner part 42 and the ring outer part 43 is not limited to the above and is arbitrary. For example, a convex part instead of the concave part may be provided as the light scattering process, or both the concave part and the convex part may be provided. Further, the light scattering treatment may be performed not on the back surfaces 42b and 43b but on the front surfaces 42a and 43a, or may be performed on both the back surfaces 42b and 43b and the front surfaces 42a and 43a. good. However, it is preferable that light is uniformly emitted from the entire front surface 42 a of the ring inner portion 42 and the entire front surface 43 a of the ring outer portion 43.

(Diffusion cover)
The diffusion cover 50 is formed of a light-transmitting material such as silicone resin, acrylic resin, polycarbonate resin, or glass, for example, and light emitted from the light guide plate 40 passes through the diffusion cover 50 and is external to the lighting device 1. Is taken out.
The diffusion cover 50 includes a dome-shaped main body 51 that covers the light guide plate 40, and a side wall 52 that extends from the peripheral edge of the main body 51 toward the back side. It is fixed to the flange portion 17 of the portion 12. The main body 51 is subjected to a light scattering process, and light emitted from the light guide plate 40 becomes scattered light when passing through the main body 51. Therefore, the luminance unevenness is further reduced. Note that the diffusion cover is not essential for the lighting device according to the present invention.

(Brightness unevenness reduction effect by reflecting member)
FIG. 8 is a diagram for explaining luminance unevenness generated in a conventional lighting device, and shows a photograph of a lighting device in a lighting state and an analysis result of luminance unevenness based on the photograph. FIG. 9 is a schematic diagram for explaining the luminance unevenness generated in the conventional lighting device, and schematically shows the luminance unevenness shown in FIG. FIG. 8 shows luminance unevenness over the diffusion cover, while FIG. 9 shows luminance unevenness on the front surface of the light guide plate.

  In a conventional direct type illumination device, for example, uneven brightness as shown in FIG. 8 occurs. As shown in FIG. 9, the portion 62 where the light emitting element 22 does not exist is a shadow region as compared with the portion 61 where the light emitting element 22 exists, and this is one of the causes of luminance unevenness. In order to reduce such luminance unevenness, in this embodiment, the portion 61 where the light emitting element 22 is present has a narrow groove width of the element accommodating groove 60, and the portion 62 where the light emitting element 22 does not exist is the element accommodating groove 60. Groove width is wide.

  FIG. 10 is a schematic diagram for explaining the path of light reflected by the element mounting surface of the substrate, showing a longitudinal section of a portion where light is emitted and 22 is not present, and for the portion where the light emitting element 22 is present. It is indicated by a two-dot chain line. L <b> 1 and L <b> 2 are return lights that are reflected by the outer peripheral surface 43 d of the outer ring portion 43 and returned into the element housing groove 60. L3 and L4 are light emitted from the light emitting element 22 but not incident on the incident surface (the surface 44b on the back side of the element array facing portion 44).

  As shown in FIG. 10, in the portion where the light emitting element 22 does not exist, the groove width of the element housing groove 60, that is, the interval between the outer peripheral surface 33a of the inner reflective member 30a and the inner peripheral surface 33b of the outer reflective member 30b is wide. Therefore, the surface 41 b on the back side of the annular portion 41 has a large area not covered with the reflecting member 30, and light is likely to enter the annular portion 41 from the element housing groove 60. Accordingly, the amount of light emitted from the front surface 41a of the annular portion 41 to the outside is large. Specifically, all the lights L1 to L4 are emitted to the outside.

  On the other hand, as indicated by the two-dot chain line, in the portion where the light emitting element 22 is present, the groove width of the element housing groove 60, that is, the distance between the outer peripheral surface 33a of the inner reflecting member 30a and the inner peripheral surface 33b of the outer reflecting member 30b. narrow. Therefore, the surface 41b on the back side of the annular portion 41 has a small area that is not covered with the reflecting member 30, and it is difficult for light to enter the annular portion 41 from the element housing groove 60. Accordingly, the amount of light emitted from the front surface 41a of the annular portion 41 to the outside is small. Specifically, the light of L1 and L3 is emitted to the outside, but the light of L2 and L4 is blocked by the reflecting member 30 and is not emitted to the outside. It heads for the part 62 where 22 does not exist.

  FIG. 11 is a schematic diagram for explaining the effect of reducing the uneven brightness by the reflecting member, and expresses the brightness by ignoring the effect of reducing the uneven brightness due to the light scattering process performed on the annular portion 41 of the light guide plate 40. ing. As shown in FIG. 11, in the present embodiment, the groove width of the element receiving groove 60 is relatively wide in the portion 62 where the light emitting element 22 does not exist. Therefore, the portion 62 where the light emitting element 22 does not exist is easier to emit light than the portion 61 where the light emitting element 22 exists. Thereby, since the luminance of the portion 62 where the light emitting element 22 does not exist is high, the luminance unevenness is reduced.

  Furthermore, in the present embodiment, the outer peripheral surface 33a of the inner reflecting member 30a, the inner peripheral surface 33b of the outer reflecting member 30b, and the element mounting surface 21a of the substrate 21 that constitute the element housing groove 60 are respectively light-transmitting. Since it is a reflecting surface, the light in the element receiving groove 60 is reflected by the element mounting surface 21a and efficiently enters the annular portion 41. Therefore, the light in the element housing groove 60 is more easily emitted from the annular portion 41, and a shadow area is less likely to occur in the annular portion 41.

  In addition, in the present embodiment, the angle θ1 formed by the outer peripheral surface 33a of the inner reflecting member 30a and the element mounting surface 21a of the substrate 21 is an acute angle, and the inner peripheral surface 33b of the outer reflecting member 30b and the element mounting of the substrate 21 are The angle θ2 formed by the surface 21a is also an acute angle. Therefore, the light in the element housing groove 60 is more likely to gather on the element mounting surface 21 a, and is easily reflected on the element mounting surface 21 a and incident on the back surface 41 a of the annular portion 41. Therefore, the light in the element housing groove 60 is more easily emitted from the annular portion 41, and a shadow area is less likely to occur in the annular portion 41. In order to make it easier for light in the element housing groove 60 to gather on the element mounting surface 21a, the angle θ1 and the angle θ2 are preferably 90 ° or less, and more preferably 45 ° to 75 °. .

(Lightness unevenness reduction effect by light guide plate)
In the conventional direct type illumination device, in the annular portion, light is emitted from the element row facing portion facing the light emitting element, but almost no light is emitted from the portion other than the element row facing portion. As shown in FIG. 8, there was a shadow area. Moreover, the brightness of the shadow area decreases as the distance from the element facing portion increases. Specifically, as shown in FIG. 9, the portion 63 close to the light emitting element 22 has high luminance, but the portion 64 far from the light emitting element 22 has low luminance, and this luminance difference is one of the causes of luminance unevenness. It has become one. In order to reduce such luminance unevenness, the annular portion 41 is subjected to light scattering processing in the present embodiment. Moreover, in the light scattering process, more light is emitted from the second light scattering portion 46 than the first light scattering portion 45, and more light is emitted from the fourth light scattering portion 48 than the third light scattering portion 47. It is given to be done.

  FIG. 12 is a schematic diagram for explaining a path of light incident directly from the light emitting element into the light guide plate. As indicated by L5 in FIG. 12, the light incident from the back surface 44b of the element array facing portion 44 is reflected by, for example, the front surface 41a of the annular portion 41 and guided into the annular inner portion 42, The inside of the ring inner portion 42 proceeds while repeating reflection between the front side surface 42 a and the back side surface 42 b of the inner side portion 42. Alternatively, as indicated by L6, the light is reflected by the front surface 41a of the annular portion 41, guided into the outer ring portion 43, and repeatedly reflected between the front surface 43a and the rear surface 43b of the outer ring portion 43. , Travels in the outer ring portion 43.

  The light of L5 and L6 is incident on the recesses 42c and 43c and becomes scattered light, and is emitted from the front surfaces 42a and 43a. For example, like the light of L6, it is radiate | emitted from the surface 43a of the front side. In addition, as the light of L5 travels in the ring inner portion 42, any of the light enters the concave portion 42c and becomes scattered light and is emitted from the front surface 42a.

  Thus, the surface 41 a on the front side of the annular portion 41 is basically a reflective surface for reflecting the light incident on the annular portion 41 and guiding it to the annular inner portion 42 or the annular outer portion 43. Therefore, it is difficult for light to be emitted from the annular portion 41, and a shadow region is likely to be generated in the annular portion 41. However, in the present embodiment, since the concave portions 45c, 46c, 47c, and 48c are provided on the front surface 41a of the annular portion 41, the front surface 41a of the annular portion 41 is also provided as indicated by L7 and L8. Light is emitted. Therefore, it is difficult for a shadow area to occur in the annular portion 41.

  In addition, the easiness of emission is not the same in all regions on the front surface 41 a of the annular portion 41. That is, it is relatively easy to emit from the second light scattering region 46a and the fourth light scattering region 48a, and relatively difficult to emit from the first light scattering region 45a and the third light scattering region 47a. This is because the number of the recessed portions 45c, 46c, 47c, 48c provided per unit area is different.

  The surface 44a on the front side of the element array facing portion 44 has an R-shaped folded portion as described above. In the folded portion, light passes through the light guide plate 40 as it is, as indicated by L9. It is emitted to the outside. Therefore, it is not necessary to provide a concave portion on the surface 44a on the front side of the element array facing portion 44 and in the vicinity thereof. If the concave portion is provided, the portion may be too bright and conspicuous. The region where no recess is provided is preferably 2 to 3 times the width of the light emitting element 22 in the longitudinal section. If it is less than 2 times, it will be too bright and noticeable. If it is more than 3 times, it will be too dark. Further, R of the folded portion is preferably 5/100 or less, and more preferably 2/100 or less. When R exceeds 5/100, the bright part is too conspicuous.

  FIG. 13 is a schematic diagram for explaining the luminance unevenness reduction effect by the light guide plate, and expresses the luminance ignoring the luminance unevenness reduction effect by the reflecting member 30. As shown in FIG. 13, in the present embodiment, since the front side surface 41 a of the annular portion 41 is subjected to light scattering processing, light is also emitted from the annular portion 41. Therefore, the luminance in the annular portion 41 is relatively higher than that of the conventional lighting device, and the luminance unevenness is reduced.

In addition, more light is emitted from the second light scattering portion 46 and the fourth light scattering portion 48 that are farther from the element row facing portion 44 than the first light scattering portion 45 and the third light scattering portion 47 that are closer to the element row facing portion 44. Is emitted, the luminance difference between the portion 63 close to the light emitting element 22 and the portion 64 far from the light emitting element 22 is eliminated, and the luminance unevenness is reduced.
(Synergistic luminance unevenness reduction effect by reflecting member and light guide plate)
FIG. 14 is a diagram for explaining the effect of reducing luminance unevenness due to the combination of the light guide plate and the reflecting member, and shows a photograph of the lighting device in the lighting state and the analysis result of the luminance unevenness based thereon. It is. FIG. 15 is a schematic diagram for explaining the effect of reducing luminance unevenness due to the combination of the light guide plate and the reflecting member, and schematically shows the luminance unevenness shown in FIG. FIG. 14 shows the luminance unevenness over the diffusion cover, while FIG. 15 shows the luminance unevenness on the front surface of the light guide plate.

  Since lighting device 1 according to the present embodiment is used in combination with reflecting member 30 and light guide plate 40, both the luminance unevenness reducing effect by the reflecting member and the luminance unevenness reducing effect by the light guide plate are both effects. Play. Therefore, the lighting apparatus 1 has almost no luminance unevenness as shown in FIGS.

  In addition, the illuminating device which concerns on this invention should just be equipped with the structure regarding a light-guide plate so that the brightness nonuniformity reduction effect by a light-guide plate can be acquired at least, and the structure regarding a reflective member is arbitrary. Therefore, a conventional configuration may be adopted for the reflecting member.

<Second Embodiment>
FIG. 16 is an exploded perspective view showing the lighting apparatus according to the second embodiment. FIG. 17 is a cross-sectional view illustrating the lighting apparatus according to the second embodiment. 18 is an enlarged cross-sectional view of a portion surrounded by a two-dot chain line shown in FIG.

  The illuminating device 100 according to the second embodiment is the illuminating device according to the first embodiment in that the reflecting member 30 is configured only by the inner reflecting member 30a and the light guide plate 140 does not include the outer ring portion. Very different from 1. Since there are many points similar to those of the lighting device 1 according to the first embodiment, only the differences between the two will be described, and the same reference numerals are used for the common configurations, and description thereof is omitted.

  As shown in FIGS. 16-18, the illuminating device 1 is provided with the case 110, the light emitting module 120, the inner side reflection member 30a, the light-guide plate 140, the diffusion cover 150, etc., for example.

(Case)
As shown in FIG. 16, the case 110 is, for example, an aluminum die-cast dish-shaped body having a bottomed cylindrical main body 111, and the main body 111 includes a disk-shaped bottom plate portion 113 and a bottom plate. And a cylindrical side wall portion 114 extending to the outer peripheral edge of the portion 113. As shown in FIG. 17, the light emitting module 120, the inner reflecting member 30 a, and a part of the light guide plate 140 are accommodated in the main body 111. Returning to FIG. 16, a through hole 115 through which the power supply line 23 is inserted is formed in the side wall portion 114 of the main body 111.

(Light emitting module)
The light emitting module 120 includes an annular plate-like substrate 121 and a plurality of light emitting elements 22 mounted on the element mounting surface 121a which is one main surface of the substrate 121, and is disposed on the back side of the light guide plate 140. ing. The light emitting elements 22 are arranged in an annular shape with a space between the light emitting elements adjacent to the element mounting surface 121a of the substrate 121 in a state where the main emission direction is directed to the light guide plate 140. The substrate 121 is substantially the same except that the outer shape is smaller than that of the substrate 21 according to the first embodiment. Each light emitting element 22 is electrically connected to the power supply line 23 through a wiring pattern (not shown) formed on the substrate 121 and a connector 24. The element mounting surface 121a of the substrate 121 is a reflecting surface for efficiently reflecting light toward the light guide plate 140 side.

(Reflective member)
The reflection member is configured only by the inner reflection member 30a according to the first embodiment, and is disposed in proximity to the light guide plate 140 on the back side of the light guide plate 140 as shown in FIG. Specifically, it is arranged on the back side of the ring inner portion 142 of the light guide plate 140 so as to avoid the light emitting element 22. In other words, the inner reflection member 30a is an annular element housing in which an annular element array composed of a plurality of light emitting elements 22 is accommodated when viewed from a direction orthogonal to the back surface (back surface 142b) of the light guide plate 140. It is arranged in a region that does not overlap with the groove (groove portion) 160.

  As shown in FIG. 18, the first light reflecting surface 31 a of the inner reflecting member 30 a faces the back surface 142 b of the ring inner portion 142 of the light guide plate 140, and reflects light leaking from the ring inner portion 142 to the back side. It plays a role of returning to the inner ring portion 142. The second light reflecting surface 32a faces the surface 146b on the back side of the second light scattering portion 146 of the annular portion 141 of the light guide plate 140, and reflects the light leaking from the second light scattering portion 146 to the back side. It plays the role of returning to the light scattering portion 146. The first light reflecting surface 31 a is in surface contact with the back surface 142 b of the ring inner portion 142, and the second light reflecting surface 32 a is in surface contact with the back surface 146 b of the second light scattering portion 146.

  The inner reflecting member 30a and the case 110 are in a state where the outer peripheral surface 33a of the inner reflecting member 30a and a part of the side wall portion 114 of the main body 111 of the case 110 face each other with a gap on the back side of the light guide plate 140. Is arranged. Accordingly, an annular element housing groove 160 in which the light emitting element 22 is housed is defined by the inner reflecting member 30 a and the case 110. On the back side of the annular portion 141 of the light guide plate 140, a portion where the inner reflection member 30 a does not exist is the element housing groove 160.

  The inner peripheral surface of the element receiving groove 160 is configured by the outer peripheral surface 33a of the inner reflecting member 30a, the outer peripheral surface of the element receiving groove 60 is configured by the inner peripheral surface of the side wall portion 114 of the case 110, and the bottom surface of the element receiving groove 160 Is constituted by an element mounting surface 121 a of the substrate 121. Further, the angle θ1 formed by the outer peripheral surface 33a of the inner reflecting member 30a and the element mounting surface 121a of the substrate 121 is an acute angle. Further, the groove width of the element receiving groove 160 is increased for a while from the front side to the back side. The inner peripheral surface of the side wall portion 114 of the case 110 is a reflecting surface.

(Light guide plate)
As shown in FIG. 16, the light guide plate 140 has a circular plate shape, an annular portion 141 formed in an annular shape along the element row composed of the light emitting elements 22, and a circle surrounded by the annular portion 141. It is comprised by the ring inner side part 142 which is plate shape. The annular portion 141 and the inner ring portion 142 are integrally formed.

  The annular portion 141 includes an element row facing portion 144, a first light scattering portion 145, and a second light scattering portion 146. The first light scattering portion 145 and the second light scattering portion 146 constitute an inner reflection portion. The element row facing portion 144 has an annular shape facing the element row composed of the plurality of light emitting elements 22. The first light scattering portion 145 has an annular shape along the element row facing portion 144 that is located inside the ring of the element row facing portion 144. The second light scattering portion 146 has an annular shape that is located inside the ring of the first light scattering portion 145 and extends along the first light scattering portion 145.

  In FIG. 17, the range indicated by reference sign W <b> 141 is the annular portion 141, and the range indicated by reference sign W <b> 142 is the ring inner side portion 142. In FIG. 18, the range indicated by the symbol W144 is the element array facing portion 144, the range indicated by the symbol W145 is the first light scattering portion 145, and the range indicated by the symbol W146 is the second light scattering portion 146.

  In addition, the light-guide plate which concerns on this invention is not limited to circular plate shape, but is arbitrary. For example, a polygonal plate shape such as a quadrangular plate shape, a hexagonal plate shape, an octagonal plate shape, or the like may be used. In addition, each shape of the annular part, the inner part of the ring, the outer part of the ring, the element array facing part, the first light scattering part, the second light scattering part, the third light scattering part, and the fourth light scattering part is also the light guide plate. It is optional depending on the shape. Furthermore, the arrangement of the light emitting elements and the shape of the substrate are arbitrary depending on the shape of the light guide plate.

  The front surface 141 a of the annular portion 141 is a reflecting surface for reflecting the light of the light emitting element 22 incident on the annular portion 141 from the back side to the annular inner portion 142. In the longitudinal section of the light guide plate 140, the shape of the surface 141a on the front side of the annular portion 141 is a substantially arc shape that swells to the front side.

  The front surface 141a of the annular portion 141 is subjected to light scattering processing. Specifically, the front side surface of the first light scattering portion 145 and the front side surface of the second light scattering portion 146 constituting the front side surface of the inner reflection portion, that is, the first light scattering region 145a and the second light scattering region. In 146a, concave portions 145c and 146c are provided as a light scattering process. Since the light scattering process is performed, the light incident on the front surface 141a from the inside of the annular portion 141 is not totally reflected, but a part thereof is scattered by the concave portions 145c and 146c, and the light guide plate 140 It is emitted to the outside. It should be noted that the front surface 144a of the element column facing portion 144 is not provided with a recess. The recesses 145c and 146c are substantially hemispherical in shape and all have the same size.

  When the first light scattering portion 145 and the second light scattering portion 146 are compared, the first light scattering region 145a and the second light scattering region 146a are subjected to different modes of light scattering processing. Specifically, the number of the concave portions 145c and 146c per unit area is larger in the second light scattering region 146a than in the first light scattering region 145a. Therefore, more light is emitted from the second light scattering portion 146 than the first light scattering portion 145.

  A part of the surface 141b on the back side of the annular portion 141 is an incident surface on which light from the light emitting element 22 is incident. The back surface 144b of the element array facing portion 144 corresponds to the incident surface. The back surface 144 b of the element array facing portion 144 has an annular shape facing the element array composed of the plurality of light emitting elements 22. Further, the entire surface 141 b on the back side of the annular portion 141 also functions as an incident surface for the light reflected by the element mounting surface 121 a of the substrate 121 in the element accommodating groove 160 to enter the annular portion 141.

  The configuration of the ring inner portion 142 is substantially the same as that of the ring inner portion 42 according to the first embodiment.

(Diffusion cover)
The diffusion cover 150 includes a dome-shaped main body 151 that covers the light guide plate 140, and a side wall 152 that extends from the peripheral edge of the main body 151 toward the back side. The side wall 152 is the main body of the case 110. It is fixed to the side wall portion 114 of the portion 111. The main body 151 is subjected to a light scattering process, and the light emitted from the light guide plate 140 becomes scattered light when passing through the main body 151.

(Brightness unevenness reduction effect by reflecting member)
Also in the present embodiment, as in the first embodiment, the groove width of the element housing groove 160 is relatively wide at a portion where the light emitting element 22 is not present (a portion corresponding to the light emitting element 22). Further, the outer peripheral surface 33a of the inner reflecting member 30a constituting the element housing groove 160 and the element mounting surface 121a of the substrate 121 are respectively light reflecting surfaces. Furthermore, an angle θ1 formed by the outer peripheral surface 33a of the inner reflecting member 30a and the element mounting surface 121a of the substrate 121 is an acute angle. Therefore, the same effect as the first embodiment can be obtained.
(Effect of reducing brightness unevenness by reflecting member and light guide plate)
Also in this embodiment, as in the first embodiment, the light scattering process is performed on the surface 141a on the front side of the annular portion 141, so that the luminance in the annular portion 141 is relatively higher than that of the conventional lighting device. And uneven brightness is reduced. Further, since more light is emitted from the second light scattering portion 146 farther to the element row facing portion 144 than the first light scattering portion 145 near the element row facing portion 144, the portion 63 closer to the light emitting element 22 and The luminance difference with the distant portion 64 is eliminated, and the luminance unevenness is reduced.

  Since lighting device 100 according to the present embodiment is used in combination with inner reflection member 30a and light guide plate 140, both the luminance unevenness reduction effect by the reflection member and the luminance unevenness reduction effect by the light guide plate are both present. There is an effect. In addition, the illuminating device which concerns on this invention should just be equipped with the structure regarding a light-guide plate so that the brightness nonuniformity reduction effect by a light-guide plate can be acquired at least, and the structure regarding a reflective member is arbitrary. Therefore, a conventional configuration may be adopted for the reflecting member.

<Modification>
Below, the modification of the illuminating device which concerns on this invention is demonstrated. FIG. 19 is a cross-sectional view for explaining a light guide plate and a reflecting member according to a modification.
(Reflective member)
In the first embodiment, the angle θ1 formed by the element mounting surface 21a of the substrate 21 and the outer peripheral surface 33a of the inner reflecting member 30a is an acute angle. However, as shown in FIG. 19, the element mounting surface 21a of the substrate 21 The angle θ1 formed by the outer peripheral surface 233a of the inner reflecting member 230a may be a right angle or an obtuse angle. In the first embodiment, the angle θ2 formed by the element mounting surface 21a of the substrate 21 and the inner peripheral surface 33b of the outer reflecting member 30b is an acute angle. However, as shown in FIG. The angle θ2 formed by the surface 21a and the inner peripheral surface 233b of the outer reflecting member 230b may be a right angle or an obtuse angle.

(Light guide plate)
Regarding the light guide plate according to the present invention, the light scattering process provided in the annular portion 41 is not limited to the first embodiment and is arbitrary. For example, a convex part instead of the concave part may be provided as the light scattering process, or both the concave part and the convex part may be provided.

  Further, in the light guide plate 40 according to the first embodiment, the light scattering process is made different by changing the number of the concave portions 45c, 46c, 47c, 48c provided on the front surface 41a of the annular portion 41 per unit area. However, the light scattering process may be made different by other methods.

  For example, in the light guide plate 240 shown in FIG. 19, the number of the recesses 45c, 46c, 47c, and 48c per unit area is the same, but different modes of light scattering processing are realized by making the sizes different. . That is, by making the area occupancy of the recesses 45c, 46c, 47c, and 48c different, the areas of the regions functioning as the light reflecting surfaces on the surface 41a on the front side of the annular part 41 are made different, thereby different aspects of the light scattering process. Is realized.

  Specifically, the number per unit area of the recesses 245c provided in the first light scattering region 245a is the same as the number per unit area of the recesses 246c provided in the second light scattering region 246a. However, each recess 245c is smaller than each recess 246c. Therefore, the area of the region functioning as the light reflecting surface in the first light scattering region 245a is smaller than the area of the region functioning as the light reflecting surface in the second light scattering region 246a. Therefore, more light is emitted from the second light scattering portion 246 than from the first light scattering portion 245.

  Moreover, since the recess 245c is smaller than the recess 246c, the light scattering function is lower than that of the recess 246c. Therefore, more light is emitted from the second light scattering region 246a than the first light scattering region 245a due to the difference in the light scattering function.

  Similarly, the number per unit area of the recesses 247c provided in the third light scattering region 247a is the same as the number per unit area of the recesses 248c provided in the fourth light scattering region 248a. However, each recess 246c is smaller than each recess 248c. Therefore, more light is emitted from the fourth light scattering portion 248 than from the third light scattering portion 247.

  It is conceivable that the size of each of the recesses 245c, 246c, 247c, 248c is changed based on the following formula 1, for example.

Dr = k1 * R ^ n / cos (m * θ) + k2 (Formula 1)
“Dr” is the diameter of the recess, “R” is the distance from the light emitting element to the recess, “θ” is the displacement angle of the recess with respect to the optical axis of the light emitting element (see FIG. 19), “k1”, “k2” ”,“ N ”, and“ m ”are constants.

  If the sizes of the recesses 245c, 246c, 247c, and 248c are changed based on Expression 1, the energy of light emitted from the recesses 245c and 246c can be adjusted. In addition, the size of the recesses may be constant, and the number of the recesses per unit area may be changed based on Equation 1.

  As described above, even when the concave portions 45c, 46c, 47c, and 48c are provided, the luminance difference between the portion close to the light emitting element 22 and the portion far from the light emitting element 22 can be eliminated, and the luminance unevenness can be reduced.

  Further, in the first embodiment, light scattering processes of different modes are performed between the element array facing portion 44 and the ring inner portion 42 in two stages of the first light scattering portion 45 and the second light scattering portion 46. However, the light scattering treatment may be performed in two or more different modes between the element row facing portion 44 and the ring inner side portion 42. Further, the light scattering process may be performed so that the light is scattered gradually away from the element array facing portion 44 as in gradation, not in steps. The same applies to the portion between the element array facing portion 44 and the outer ring portion 43.

(Other)
As mentioned above, although the structure of the illuminating device which concerns on this invention was demonstrated based on embodiment and a modification, this invention is not limited to the said embodiment and its modification. For example, the structure which combined suitably the said embodiment and the partial structure of the modification may be sufficient. In addition, the materials, numerical values, and the like described in the above embodiments are merely preferable examples and are not limited thereto. Furthermore, it is possible to appropriately change the configuration without departing from the scope of the technical idea of the present invention.

  The lighting device according to the present invention can be widely used in general lighting applications such as a ceiling light, a downlight, and a backlight.

DESCRIPTION OF SYMBOLS 1,100 Illuminating device 21,121 Board | substrate 21a, 121a Element mounting surface 22 Light emitting element 30 Reflective member 30a, 230a Inner reflecting member 30b, 230b Outer reflecting member 31a, 32a Light reflecting surface of inner reflecting member 32b, 32b Outer reflecting member Light reflecting surface 33a, 233a Inner reflecting portion outer peripheral surface 33b, 233b Outer reflecting member inner peripheral surface 40, 140, 240 Light guide plate 41, 141 Annular portion 42, 142 Annular inner portion 43, 143 Annular outer portion 44, 144 Element Column facing portion 44b, 144b Incident surface 45, 145, 245 First light scattering portion (inner reflection portion)
45a, 145a, 245a First light scattering region 46, 146, 246 Second light scattering part (inner reflection part)
46a, 146a, 246a Second light scattering region 47a, 147a, 247a Third light scattering region 48a, 148a, 248a Fourth light scattering region 45c, 46c, 47c, 48c, 145c, 146c, 245c, 246c, 247c, 248c 47,247 Third light scattering portion (outside reflection portion)
48,248 Fourth light scattering portion (outside reflection portion)
60,160 Element receiving groove (groove)

Claims (8)

A plurality of light emitting elements are annularly arranged on the back side of the light guide plate with their respective main emission directions facing the light guide plate , and a reflection member having a light reflection surface is provided on the back side of the light reflection surface and the light guide plate. A lighting device disposed in proximity to the light guide plate in a state where a part of the surface is opposed ,
The light guide plate includes an annular portion formed in an annular shape along an element row composed of the plurality of light emitting elements, and an annular inner portion formed continuously with the annular portion on the inner side of the annular portion,
The reflection member is disposed on a back side of the inner ring portion and a part of a back side of the annular portion so as to avoid an element row composed of the plurality of light emitting elements, and the plurality of light emission by the reflection member. An annular groove for accommodating the element is defined,
The groove portion has a wider groove width at a portion corresponding to a gap between adjacent light emitting elements than a groove width at a portion corresponding to each light emitting element,
The annular portion is a portion facing the element row and having an incident surface on which light emitted from the light emitting element is incident, and the annular portion is located closer to the inner side of the ring than the element row facing portion An inner reflecting portion having a reflecting surface that reflects the light incident from the incident surface toward the inner side of the ring,
The reflection surface is a ring-shaped first light scattering region that has been subjected to light scattering processing along the element array facing portion, and a region closer to the inner side of the ring than the first light scattering region. An illumination apparatus comprising: a second light scattering region that has been subjected to a light scattering process different from the first light scattering region so that more light is emitted than the one light scattering region.   2. The illumination device according to claim 1, wherein a concave portion and / or a convex portion are provided on the reflection surface as a light scattering process performed on the first light scattering region and the second light scattering region.   The lighting device according to claim 2, wherein the second light scattering region has a larger number per unit area of the concave portion and the convex portion than the first light scattering region.   The lighting device according to claim 2, wherein the second light scattering region has a higher area occupancy ratio of the concave portion and the convex portion than the first light scattering region. The light guide plate further includes an annular outer portion formed continuously with the annular portion on the outer ring side of the annular portion,
The annular portion is a portion located on the outer ring side of the element array facing portion, and further includes an outer reflection portion having a reflection surface for reflecting light incident from the incident surface toward the outer ring portion. Prepared,
The reflection surface of the outer reflection portion is a ring-shaped third light scattering region that has been subjected to light scattering treatment along the element array facing portion, and a region closer to the outer ring side than the third light scattering region. And a fourth light scattering region that has been subjected to a light scattering process different from the third light scattering region so that more light is emitted than the third light scattering region. The lighting device according to claim 1.   The concave portion and / or the convex portion are provided on a reflection surface of the outer reflection portion as a light scattering treatment performed on the third light scattering region and the fourth light scattering region. Lighting equipment.   The lighting device according to claim 5, wherein the number of the concave portions and the convex portions per unit area is larger in the fourth light scattering region than in the third light scattering region.   The lighting device according to claim 6, wherein the fourth light scattering region has a higher area occupancy ratio of the concave portion and the convex portion than the third light scattering region.

Images