Lighting equipment

Abstract

To provide a luminaire that can reduce a clearance between components to easily enhance light utilization efficiency, and the easily emit desired light.SOLUTION: A luminaire 1 comprises: a light source; a light guide plate 30 which is located on one Z-directional side about the light source, and has an end surface that light emitted from the light source to the other Z-directional side impinges on, and can define a thickness direction as an X direction; and an integration structure 45 which integrates the light guide plate 30 and light source. The integration structure 45 has at least one of a Z-directional expansion / contraction absorption structure 55 which can absorb Z-directional expansion and contraction, and prevents a Z-directional clearance from being formed between the integration structure 45 and light guide plate 30, and an X-directional expansion / contraction absorption structure 65 which can absorb X-directional expansion and contraction, and prevents an X-directional clearance from being formed between the integration structure 45 and light guide plate 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a lighting device. [Background technology]

[0002] Conventionally, as described in Patent Document 1, in a lighting device that uses a resin part in a fixing structure for fixing a light guide plate, a clearance is provided between the resin part and the light guide plate to prevent damage to the resin part or the light guide plate due to excessive stress generated in the resin part and the light guide plate when the resin part thermally expands. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-101092 A Summary of the Invention [Problem to be solved by the invention]

[0004] The clearance makes it difficult to efficiently direct light from the light source into the light guide plate, which tends to reduce the light utilization efficiency. Also, the clearance makes it difficult to achieve desired light emission, which tends to cause variations in the arrangement positions of components.

[0005] Therefore, an object of the present disclosure is to provide a lighting device that can reduce the clearance between components, can easily increase the light utilization efficiency, and can easily emit desired light. [Means for solving the problem]

[0006] In order to solve the above problems, the lighting device disclosed herein includes a light source, a light guide plate that is located on one side of the light source in a first direction and has an end face into which light projected from the light source to one side in the first direction is incident and that can define a thickness direction that is a second direction, and an integrated structure that integrates the light guide plate and the light source, wherein the integrated structure has at least one of a first direction expansion / contraction absorption structure that can absorb expansion and contraction in the first direction and prevent a clearance in the first direction from occurring between the integrated structure and the light guide plate, and a second direction expansion / contraction absorption structure that can absorb expansion and contraction in the second direction and prevent a clearance in the second direction from occurring between the integrated structure and the light guide plate.

[0007] The first direction may coincide with a height direction of the lighting device, and the second direction may coincide with a depth direction of the lighting device. Effect of the Invention

[0008] According to the lighting device of the present disclosure, at least one of the clearance between components in the first direction and the clearance between components in the second direction can be eliminated, making it easier to increase the light utilization efficiency and to emit desired light. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a light source unit which is a main part of an illumination device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view of the light source unit. [Diagram 3] FIG. 4 is a front view of the light source unit as viewed from one side in the thickness direction of the light guide plate. [Figure 4] FIG. 4 is an enlarged front view of a region indicated by R in FIG. [Diagram 5] 4 is a perspective view of a first member of the light source unit as viewed from the front side. FIG. [Figure 6] FIG. 2 is a perspective view of the first member as viewed from the back side. [Figure 7] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 8]FIG. 4 is a side view of the light source unit as viewed from the side. [Figure 9] 4 is a perspective view of a second member of the light source unit as viewed from a first member side. FIG. [Figure 10] 9 is a cross-sectional view taken along line BB in FIG. 8. [Figure 11] 9 is a cross-sectional view taken along line CC in FIG. 8. [Figure 12] FIG. 4 is a cross-sectional view taken along line DD in FIG. [Figure 13] 4 is a cross-sectional view taken along line EE in FIG. [Figure 14] FIG. 4 is a cross-sectional view taken along the line FF in FIG. [Figure 15] FIG. 4 is an exploded perspective view illustrating the assembly of the light source unit. [Figure 16] FIG. 4 is an exploded front view illustrating the assembly of the light source unit. [Figure 17] 11 is a perspective view of a lower integrated member of the light source unit as viewed from above in a height direction. FIG. [Figure 18] 9 is a cross-sectional view taken along line GG in FIG. 8. [Figure 19] 13 is a diagram for explaining the structure of an upper portion in the height direction of a lighting device according to a modified example, and is a diagram showing a cross section of a part of the upper portion in the height direction. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. In addition, when multiple embodiments and modified examples are included in the following, it is assumed from the beginning that new embodiments will be constructed by appropriately combining the characteristic parts of those. In addition, in the following examples, the same components are given the same symbols in the drawings, and duplicated explanations are omitted. In addition, multiple drawings include schematic diagrams, and the dimensional ratios of length, width, height, etc. of each member do not necessarily match between different drawings. In addition, among the components described below, components that are not described in the independent claim showing the highest concept are optional components and are not essential components. In addition, when the word "approximately" is used in this specification, it is used in the same sense as the word "roughly speaking", and the requirement of "approximately ~" is satisfied if a person looks roughly ~. For example, the requirement of approximately circular is satisfied if a person looks roughly circular. In addition, in the drawings and the following description, the X direction is the second direction, which coincides with the thickness direction of the light guide plate 30 described below and coincides with the depth direction of the lighting device 1. Moreover, the Y direction is a third direction, which coincides with the lateral direction (width direction) of the light guide plate 30 and coincides with the lateral direction (width direction) of the lighting device 1. Moreover, the Z direction is a first direction, which coincides with the height direction of the light guide plate 30 and coincides with the height direction of the lighting device 1. The X direction, the Y direction, and the Z direction are perpendicular to each other.

[0011] FIG. 1 is a perspective view showing a light source unit 5, which is a main part of a lighting device 1 according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the light source unit 5. The light source unit 5 is embedded and fixed in a recess provided in a side wall located on the side of a road, a sidewalk, a footpath, or an alley where people walk, or is used as a light-emitting part of a pole light, and has a role of illuminating people's feet and the road surface where people walk. A power supply device (not shown) of the lighting device 1 is disposed in a place other than the light source unit 5 in the side wall or the case of the pole light. Although not described in detail, the power supply device converts AC power from a commercial power source into DC power, and also reduces the voltage to an appropriate voltage to supply it to the light source unit 5.

[0012] As shown in FIG. 1, the light source unit 5 includes a light guide plate 30, an integrated structure 45, a reflector 80, and a lower integrated member 85. As shown in FIG. 2, the light source unit 5 includes a light source 20 and a rod-shaped elastic heat dissipation member 90. As shown in FIG. 1, the integrated structure 45 includes a first member 50 and a second member 70, and each of the first member 50 and the second member 70 is made of a resin material, for example, polycarbonate resin, epoxy resin, PBT (polybutylene terephthalate) resin, ABS resin, or the like. The elastic heat dissipation member 90 is made of a material that has good heat dissipation properties and elasticity, and may be formed by mixing a plurality of particles (for example, metal particles) with excellent thermal conductivity into a rubber material such as silicone rubber, or may be formed by mixing a plurality of particles with excellent thermal conductivity and electrical insulation into a rubber material such as silicone rubber. In this case, when silicone rubber is used as the rubber material, the elastic heat dissipation member 90 has the properties specific to silicone rubber, such as heat resistance and electrical insulation, which is preferable. The elastic heat dissipation member 90 may be composed of any known elastic heat dissipation sheet. The integrated structure 45 integrates the light source 20, the light guide plate 30, and the reflector 80 together on the upper side in the Z direction, while the lower integrated member 85 integrates the light guide plate 30 and the reflector 80 together on the lower side in the Z direction. These integrated structures will be described in detail later.

[0013] As shown in Fig. 2, the light source 20 has a substrate 21, a plurality of LEDs (Light Emitting Diodes) (not shown), and a sealing member 22 that seals all of the LEDs on one side. The substrate 21 has a long and narrow plate shape and is made of, for example, a ceramic substrate, a resin substrate, or a metal-based substrate. A pair of electrode terminals 23 and a metal wiring having a predetermined pattern are formed on the substrate 21. The pair of electrode terminals 23 are provided for receiving DC power from the outside for making the LEDs emit light. The metal wiring having the predetermined pattern is provided for electrically connecting the LEDs to each other.

[0014] The LEDs are mounted in a row on a mounting surface located on one side of the substrate 21 at intervals in the extension direction (lateral direction) of the substrate 21. The LEDs are, for example, bare chips that emit monochromatic visible light. The sealing member 22 is, for example, made of a translucent resin. The LEDs may be blue LED chips that emit blue light when powered, and the sealing member 22 may include a phosphor. When the light source 20 emits white light and the LEDs are blue LED chips that emit blue light, the sealing member 22 is, for example, made of a phosphor-containing resin in which phosphor particles are dispersed in a silicone resin, and the phosphor particles are, for example, made of a YAG-based yellow phosphor.

[0015] The sealing member 22 may seal all the LEDs collectively, or may seal each LED individually. In the configuration of this embodiment shown in FIG. 2, the sealing member 22 seals all the LEDs collectively, so that the light emitted from the multiple LEDs is diffused linearly by the sealing member 22, and the light source 20 emits linear light like a linear light source. The light source may include a light-emitting element other than an LED, may include a semiconductor laser element as a light-emitting element, or may include a solid-state light-emitting element such as an organic EL (Electro Luminescence) element or an inorganic EL element. Alternatively, the light source may be composed of an incandescent lamp.

[0016] The integrated structure 45 has a Z-direction expansion / contraction absorbing structure as a first direction expansion / contraction absorbing structure that can absorb expansion and contraction in the Z-direction, which is a first direction, and prevents a clearance in the Z-direction from occurring between the integrated structure 45 and the light guide plate 30. The integrated structure 45 also has an X-direction expansion / contraction absorbing structure as a second direction expansion / contraction absorbing structure that can absorb expansion and contraction in the X-direction, which is a second direction, and prevents a clearance in the X-direction from occurring between the integrated structure 45 and the light guide plate 30. The Z-direction expansion / contraction absorbing structure can reduce the clearance in the Z-direction and reduce the variation in the position between the components in the Z-direction. The X-direction expansion / contraction absorbing structure can reduce the clearance in the X-direction and reduce the variation in the position between the components in the X-direction. The integrated structure 45 also has a Y-direction positioning structure that can reduce the variation in the position between the components in the Y-direction. Below, these structures will be described in the order of the Z-direction expansion / contraction absorbing structure, the X-direction expansion / contraction absorbing structure, and the Y-direction positioning structure.

[0017] (Z-direction expansion / contraction absorbing structure) FIG. 3 is a front view of the light source unit 5 as viewed from one side in the X direction, and FIG. 4 is an enlarged front view of the area indicated by R in FIG. 3. As shown in FIGS. 1 and 3, the first member 50 has a plurality of first through holes 51 penetrating the first member 50 in the X direction. The first through holes 51 have a substantially rectangular shape in a plan view as viewed from the X direction. As shown in FIG. 4, the first through hole 51 has a pair of height direction extending surfaces 51a, 51b and a pair of horizontal direction extending surfaces 51c, 51d. The pair of height direction extending surfaces 51a, 51b are spaced apart in the Y direction and extend in a direction substantially parallel to a plane including the X direction and the Z direction. The pair of horizontal direction extending surfaces 51c, 51d are spaced apart in the Z direction and extend in a direction substantially parallel to a plane including the X direction and the Y direction.

[0018] The Z-direction expansion / contraction absorbing structure 55 is located at a position overlapping the first through hole 51 when viewed from the X-direction. More specifically, as shown in FIG. 4, the Z-direction expansion / contraction absorbing structure 55 includes a horizontally extending surface 51c located on the upper side in the Z-direction as the first side in the first direction on the inner surface of the first through hole 51. The horizontally extending surface 51c constitutes a contact portion. The Z-direction expansion / contraction absorbing structure 55 also has a plurality of protruding portions 31 protruding in the X-direction from one side surface in the X-direction of the light guide plate 30. The protruding portions 31 have a substantially rectangular parallelepiped shape and have a pair of horizontally extending surfaces 31a, 31b facing each other in the Z-direction. The pair of horizontally extending surfaces 31a, 31b extend in a direction substantially parallel to a plane including the X-direction and the Y-direction.

[0019] The Z-direction expansion / contraction absorbing structure 55 further has a Z-direction pressing portion 57 as a first direction pressing portion that has flexibility and presses the horizontally extending surface 31b, which is the end portion on the lower side in the Z direction as the second side in the second direction of the protruding portion 31, toward the horizontally extending surface 51c. Fig. 5 is a perspective view of the first member 50 as seen from the front side, and Fig. 6 is a perspective view of the first member 50 as seen from the back side.

[0020] As shown in Figs. 4 to 6, the Z-direction pressing portion 57 extends from a height direction extending surface 51a located on a first side in the Y direction in the first through hole 51 to a second side in the Y direction. The Z-direction pressing portion 57 has excellent flexibility in the Z direction. More specifically, the first member 50 is made of a resin material with excellent toughness. Also, as shown in Fig. 4, the Z-direction pressing portion 57 is located at a distance in the Z direction from both of the pair of horizontal direction extending surfaces 51c, 51d of the first through hole 51, and can bend in the Z direction.

[0021] Furthermore, the Z-direction pressing portion 57 includes a first horizontal extension portion 57a, an inclined portion 57b, and a second horizontal extension portion 57c. The first horizontal extension portion 57a ​​extends from the height direction extension surface 51a to the second side in the Y direction. The inclined portion 57b extends from the end portion of the first horizontal extension portion 57a ​​opposite to the height direction extension surface 51a side to the second side in the Y direction and upward in the Z direction, and is displaced upward in the Z direction as it approaches the second side in the Y direction. The second horizontal extension portion 57c extends from the end portion of the inclined portion 57b opposite to the first horizontal extension portion 57a ​​side to the second side in the Y direction. Therefore, the Z-direction pressing portion 57 is easily deflected in the Z direction due to the presence of the inclined portion 57b.

[0022] 4, the second horizontally extending portion 57c of the flexible Z-direction pressing portion 57 presses the horizontally extending surface 31b, which is the lower end surface of the protrusion 31, against the horizontally extending surface 51c, which constitutes the upper inner surface of the first through hole 51, which constitutes the contact portion. The protrusion 31 is sandwiched between the Z-direction pressing portion 57 and the horizontally extending surface 51c. The Z-direction pressing portion 57 is designed to bend slightly in the Z direction while pressing the protrusion 31.

[0023] 3, there is a plane that allows the light source unit 5 to be plane-symmetrical including the X direction and the Z direction, and the Z direction pressing parts 57 are present on both sides in the Y direction. Therefore, with this structure, the Z direction expansion / contraction absorption structure 55 can absorb the clearance in the Z direction between the first member 50 and the light guide plate 30 over the entire area in the Y direction, and in the lighting device 1, no clearance in the Z direction occurs between the first member 50 and the light guide plate 30.

[0024] Furthermore, the integrated structure 45 and the light source 20 can reduce the clearance in the Z direction by the following structure. In detail, Fig. 7 is a cross-sectional view taken along line AA in Fig. 3, which is a cross-sectional view of the light source unit 5 cut by the plane P. As shown in Fig. 7, the first member 50 has a board accommodating recess 58 whose Z-direction dimension is the same as or slightly smaller than the thickness of the board 21, and the board accommodating recess 58 opens toward the second member 70 in the X direction. In addition, the second member 70 has a board accommodating recess 78 whose Z-direction dimension is the same as or slightly smaller than the thickness of the board 21, and the board accommodating recess 78 opens toward the first member 50 in the X direction.

[0025] The second side (light emission side) in the X direction of the substrate 21 is inserted into the substrate accommodating recess 58 by press-fitting or the like, and the first side (opposite the light emission side) in the X direction of the substrate 21 is inserted into the substrate accommodating recess 78 by press-fitting or the like. Thereafter, the first member 50 and the second member 70 are integrated in the following structure. In detail, FIG. 8 is a side view of the light source unit 5 as viewed from one side in the Y direction, and FIG. 9 is a perspective view of the second member 70 as viewed from the first member side 50. Also, FIG. 10 is a cross-sectional view taken along line BB in FIG. 8, which is a cross-sectional view of the lower side of the integrated structure 45 in the Z direction cut by a plane including the X direction and the Y direction.

[0026] As shown in FIG. 6, the first member 50 has a plurality of flexible engaging claws 62 that protrude toward the second member 70 in the X direction. The engaging claws 62 are located on both sides in the Y direction, and on both sides in the Z direction with respect to each Y direction side. Each engaging claw 62 has an X direction extending portion 63 and a folded portion 64 that is connected to the tip of the X direction extending portion 63 and folded back toward the center side in the Y direction. On the other hand, as shown in FIG. 9, the second member 70 has a plurality of engaging recesses 82. The engaging recesses 82 are located on both sides in the Y direction, and on both sides in the Z direction with respect to each Y direction side. As shown in FIG. 10, an engaging protrusion 84 that engages the folded portion 64 of the engaging claw 62 in the X direction is provided in the engaging recess 82. The folded portion 64 of each engaging claw 62 is engaged with the engaging protrusion 84 by snap fit. In detail, the folded portion 64 of each engagement claw 62 is caused to overcome the engagement protrusion 84 by distorting the X-direction extending portion 63 outward in the Y-direction, and then engaged with the engagement protrusion 84, thereby fixing the first member 50 to the second member 70 so that it cannot move relative to the first member 50.

[0027] Thereafter, the rod-shaped elastic heat dissipation member 90 shown in FIG. 1 is pressed into the elastic heat dissipation member press-fit recess 98 (see FIG. 7) formed in the integrally integrated first and second members 50, 70, and the elastic heat dissipation member 90 presses the substrate 21 downward. As shown in FIG. 7, by pressing the elastic heat dissipation member 90, a part of the LED mounting surface of the substrate 21 is brought into contact with the end face 59 on the upper side in the Z direction of the first member 50, and another part of the LED mounting surface of the substrate 21 is brought into contact with the end face 79 on the upper side in the Z direction of the second member 70. This suppresses the generation of a clearance in the Z direction of the light source 20 relative to the first and second members 50, 70. FIG. 11 is a cross-sectional view of the CC line in FIG. 8, and is a cross-sectional view of the light guide unit 5 cut by a plane that passes through the center of the light guide plate 30 in the X direction and includes the Y direction and the Z direction. As also shown in Figure 11, when the elastic heat dissipation member 90 is pressed to a predetermined position into the elastic heat dissipation member press-fit recess 98 (see Figure 7) to form the integrated structure 45, a portion of the LED mounting surface of the board abuts against the upper end face of the second member 70 in the Z direction.

[0028] (X-direction expansion / contraction absorbing structure) Next, reduction of the clearance in the X direction and reduction of the variation in the component position in the X direction will be described. As shown in Fig. 1 and Fig. 3, the first member 50 has a plurality of second through holes 52 penetrating the first member 50 in the X direction. The second through holes 52 have a substantially rectangular shape in a plan view when viewed from the X direction.

[0029] 5, the second through hole 52 has a pair of height-direction extending surfaces 52a, 52b and a pair of horizontal-direction extending surfaces 52c, 52d. The pair of height-direction extending surfaces 52a, 52b are spaced apart in the Y direction and extend in a direction substantially parallel to a plane including the X direction and the Z direction. The pair of horizontal-direction extending surfaces 52c, 52d are spaced apart in the Z direction and extend in a direction substantially parallel to a plane including the X direction and the Y direction.

[0030] As shown in FIG. 3, the X-direction expansion / contraction absorption structure 65 is located at a position overlapping the second through-hole 52 when viewed from the X-direction. More specifically, as shown in FIG. 5, the X-direction expansion / contraction absorption structure 65 has an X-direction pressing portion 67 as a second-direction pressing portion that has flexibility and abuts against a surface on the second side (light-emitting side) in the X-direction of the light guide plate 30. As shown in FIG. 5 and FIG. 6, the X-direction pressing portion 67 extends from the height direction extending surface 52a located on the first side in the Y direction in the second through-hole 52 to the second side in the Y direction. The X-direction pressing portion 67 has excellent flexibility in the X-direction. More specifically, the first member 50 is made of a resin material having excellent toughness as described above. Also, as shown in FIG. 5, the X-direction pressing portion 67 is located at a distance in the Z direction from both of the pair of horizontal direction extending surfaces 52c, 52d of the second through-hole 52, and can bend in the X direction.

[0031] 5 and 6, the X-direction pressing portion 67 includes a first horizontally extending portion 67a, an inclined portion 67b, and a second horizontally extending portion 67c. The first horizontally extending portion 67a extends from the height-direction extending surface 52a to a second side in the Y-direction. The inclined portion 67b extends from an end portion of the first horizontally extending portion 67a opposite to the height-direction extending surface 52a side to a first side in the X-direction (opposite the light output side) and a second side in the Y-direction, and is displaced toward the first side in the X-direction as it approaches the second side in the Y-direction. The second horizontally extending portion 67c extends from an end portion of the inclined portion 67b opposite to the first horizontally extending portion 67a side to the second side in the Y-direction. Therefore, the X-direction pressing portion 67 is easily bent in the X-direction due to the presence of the inclined portion 67b.

[0032] 12 is a cross-sectional view taken along line DD in FIG. 3, and is a cross-sectional view when the light source unit 5 is cut by a plane that includes the X direction and the Y direction and passes through approximately the center in the height direction of the X-direction pressing portion 67. As shown in FIG. 12, in a state in which the first member 50 and the second member 70 are integrated and integrated by the above-mentioned snap fit, the integrated structure 45 has one or more abutment surfaces 81 that abut against a part of the surface of the first side in the X direction of the light guide plate 30, and the second horizontally extending portion 67c of the X-direction pressing portion 67 presses the surface 35 of the second side in the X direction of the light guide plate 30 toward the abutment surface 81.

[0033] The light guide plate 30 is sandwiched in the X direction between the second horizontal extension portion 67c of the X direction pressing portion 67 and the abutment surface 81. In this embodiment, the abutment surface 81 is included in the second member 70. The X direction pressing portion 67 is designed to bend slightly in the X direction while pressing the light guide plate 30. As shown in FIG. 3, there is a plane that can make the light source unit 5 plane-symmetrical including the X direction and the Z direction, and the X direction pressing portion 67 is present on both sides in the Y direction. Therefore, with this structure, the X direction expansion contraction absorption structure 65 can absorb the clearance in the X direction between the first member 50 and the light guide plate 30 in the entire area in the Y direction, and in the lighting device 1, no clearance in the X direction is generated between the first member 50 and the light guide plate 30.

[0034] Furthermore, the following structure makes it possible to reduce the clearance in the X direction between the integrated structure 45 and the light source 20. Fig. 13 is a cross-sectional view taken along line EE in Fig. 3, and is a cross-sectional view of the light source unit 5 cut along a plane that includes the X direction and the Y direction and passes through the engagement claw 62 and the engagement protrusion 84 located on the upper side in the Z direction.

[0035] 13, the substrate 21 has a first edge 21a and a second edge 21b that are spaced apart in the X direction and extend substantially in the Y direction perpendicular to both the X direction and the Z direction. The integrated structure 45 has a substrate abutment surface 76 that abuts against an end surface 21c of the first edge 21a, and a plurality of protrusions 56 that press an end surface 21d of the second edge 21b against the substrate abutment surface 76. By pressing the substrate 21 against the second member 70 using the plurality of protrusions 56, the clearance in the X direction that occurs between the integrated structure 45 and the light source 20 can be reduced.

[0036] (Y-direction positioning structure) Next, a Y-direction positioning structure 75 that enables the positioning of the light guide plate 30 in the Y direction relative to the integrated structure 45 will be described. As shown in FIG. 3, the first member 50 has one or more third through holes 53 penetrating the first member 50 in the X direction. The third through holes 53 form insertion holes. In this embodiment, the first member 50 has only one third through hole 53, and the third through hole 53 is provided in the center in the Y direction, but the lighting device of the present disclosure does not need to adopt this configuration. The third through hole 53 has a substantially rectangular shape in a plan view when viewed from the X direction.

[0037] FIG. 14 is a cross-sectional view of the line FF in FIG. 3, and is a cross-sectional view when the light source unit 5 is cut by a plane including the X direction and the Y direction and passing through the central axis of the third through hole 53. As shown in FIG. 14, the light guide plate 30 has a one-side protruding portion 39 that protrudes from an end face (a surface that mainly emits light) on the second side in the X direction to the second side in the X direction. This one-side protruding portion 39 is fitted into the third through hole 53. In this embodiment, the one-side protruding portion 39 has a conical outer peripheral surface 39a whose outer diameter becomes smaller toward the tip side. In addition, the maximum outer diameter of the conical outer peripheral surface 39a is larger than both the dimension in the Y direction and the dimension in the Z direction of the third through hole 53. Therefore, the tip side of the one-side protruding portion 39 can be press-fitted into the third through hole 53, and the one-side protruding portion 39 can be firmly fixed to the third through hole 53. The engagement of the one-side protrusion 39 with the third through hole 53 limits the relative movement of the light guide plate 30 with respect to the first member 50 in the Y direction, and in this embodiment, the relative movement of the light guide plate 30 with respect to the first member 50 in the Y direction can be substantially prevented. The shape of the third through hole in a plan view when viewed from the X direction may be any shape, and for example, the third through hole may be a cylindrical hole having a cylindrical inner peripheral surface. When the third through hole (insertion hole) is a cylindrical hole having a cylindrical inner peripheral surface, the minimum outer diameter of the conical outer peripheral surface 39a is smaller than the inner diameter of the cylindrical inner peripheral surface, but it is preferable that the maximum outer diameter of the conical outer peripheral surface 39a is larger than the inner diameter of the cylindrical inner peripheral surface, since the integrated structure with respect to the light guide plate can be precisely positioned in the X direction.

[0038] (Assembling the light source unit) Next, the assembly of the light source unit 5 will be described. As shown in FIG. 2, the reflector 80 has a plurality of through holes 83 penetrating the reflector 80 in the X direction, and the second member 70 has a plurality of protrusions 74 whose shape in plan view when viewed from the X direction substantially matches the shape of the plurality of through holes 83 in plan view. When constructing the integrated structure 45, the protrusions 74 are inserted into the through holes 83 to suppress the reflector 80 from moving relative to the second member 70, and the reflector 80 is positioned relative to the second member 70. The reflector 80 may be made of any material that has the property of totally reflecting light, and may be made of, for example, acrylic resin, ABS resin, aluminum having one side surface mirror-finished, or stainless steel having one side surface mirror-finished.

[0039] Fig. 15 is an exploded perspective view for explaining the assembly of the light source unit 5, and Fig. 16 is an exploded front view for explaining the assembly of the light source unit 5. First, referring to Fig. 15, a first side in the X direction of the substrate 21 of the light source 20 is pushed all the way into a substrate accommodating recess 78 extending in the Y direction and provided in the second member 70 for inserting the substrate 21, with the LED in an attitude of emitting light downward in the Z direction. Next, the multiple protrusions 74 of the second member 70 are fitted into the multiple through holes 83 of the reflector 80. Next, the light guide plate 30 is placed on the reflector 80. 4, 10 and 14 in addition to Fig. 15, the first member 50 is moved toward the second member 70, the one-side protrusion 39 of the light guide plate 30 is fitted into the third through-hole 53 of the first member 50, and the multiple protrusions 31 located on both sides in the Y direction of the light guide plate 30 are sandwiched between the Z-direction pressing portion 57 and the horizontally extending surface 51c, and further the engagement claw 62 of the first member 50 is engaged by snap fit with the engagement protrusion 84 of the engagement recess 82 of the second member 70 integrated with the light source 20 and the reflector 80. As a result, the main components of the light source unit 5 are assembled and integrated into one body. Then, referring to Figures 7 and 16, the elastic heat dissipation member 90 is pressed from above in the Z direction into the elastic heat dissipation member press-fit recess 98 (see Figure 7) formed in the integrally integrated first and second members 50, 70, thereby assembling an integrated structure 45 that integrates the conductive plate 30 and the light source 20.

[0040] Next, the fixing of the lower integrated member 85 to the integrated structure 45 will be described. Fig. 17 is a perspective view of the lower integrated member 85 as viewed from above in the Z direction. As shown in Fig. 17, the lower integrated member 85 has a recess 89 that opens upward in the Z direction, and the X-direction dimension of this recess 89 is approximately equal to the sum of the thickness of the light guide plate 30 and the thickness of the reflector plate 80. In addition, the reflector plate 80 has approximately the same Y-direction dimension as the light guide plate 30, but the Y-direction dimension of the recess 89 is approximately equal to both the Y-direction dimension of the reflector plate 80 and the Y-direction dimension of the light guide plate 30.

[0041] When the integrated structure 45 is assembled, the light guide plate 30 and the reflector 80 are positioned so that all parts of the light guide plate 30 and the reflector 80 are substantially overlapped when viewed from the Z direction. The lower ends of the light guide plate 30 and the reflector 80 in this overlapping state are pressed into the recess 89 of the lower integrated member 85 to be fixed. FIG. 18 is a cross-sectional view taken along line GG in FIG. 8, showing the light source unit 5 cut along a plane that includes the Y direction and the Z direction and passes through the center of the light guide plate 30 in the X direction. As shown in FIGS. 17 and 18, the lower integrated member 85 has a covering portion 88 that covers both sides in the Y direction at the lower end of the light guide plate 30 in the Z direction, and the covering portion 88 is provided with a recess 86 recessed outward in the Y direction.

[0042] 18, the light guide plate 30 has protrusions 36 that protrude outward in the Y direction from end faces located on both sides in the Y direction. In a plan view seen from the X direction, the shape of the protrusions 36 approximately matches the shape of the recesses 86. By fitting the protrusions 36 into the recesses 86, the lower integrated member 85 can be accurately positioned in the Z direction relative to the light guide plate 30, and the lower integrated member 85 can be attached to the integrated structure 45. By attaching the lower integrated member 85 to the light guide plate 30, the assembly of the light source unit 5 is completed.

[0043] (Other configurations) Although not shown, a plurality of prisms are provided on the surface of the first side (reflector 80 side) in the X direction of the light guide plate. The shape of the prisms may be any shape, and the plurality of prisms may include a prism composed of a plurality of truncated cone-shaped recesses, a prism composed of a plurality of cone-shaped recesses, a prism composed of a plurality of dimple-shaped recesses, or a prism composed of a plurality of groove-shaped recesses extending in the Y direction. The plurality of prisms may include two or more different types of prisms, and each type of prism may be present in a plurality of types. The light source unit 5 is arranged such that the Z direction coincides with the vertical direction and the first member 50 is located vertically above the lower integrated member 85 in a usage state.

[0044] In such an arrangement, referring to FIG. 7, the light projected downward from the LED 29 of the light source 20 located on the upper side enters the light guide plate 30 through the end surface 38 on the upper side in the Z direction of the light guide plate 30. Then, the main light of the light incident on the light guide plate 30 is reflected by the prism and emitted in a direction including the second side in the X direction and the lower side in the Z direction from the surface on the side on which the prism is not formed in the thickness direction of the light guide plate 30. Here, if the multiple prisms include multiple prisms composed of groove-shaped recesses extending in the Y direction, the light emitted from the light guide plate 30 can be emitted downward so as to effectively spread in the Y direction, and the road surface and the feet of people can be irradiated over a wide area in the Y direction, which is preferable. As the shape of the prism and the formation position of the prism of each shape, for example, various shapes and various formation positions described in JP 2020-4610 A (applicant: Panasonic IP Management Co., Ltd.) can be adopted.

[0045] The above description has been given of a case where a prism is formed on the first side surface in the X direction of the light guide plate 30, and the light source unit 5 includes a reflector 80 covering the first side surface, and where light is mainly emitted from the second side surface in the X direction of the light guide plate 30. However, the light source unit may be configured not to include a reflector, and may be configured such that light is emitted from the second side surface in the X direction of the light guide plate and also from the first side surface in the X direction of the light guide plate. Also, a plurality of prisms may be formed on the first side surface in the X direction and also on the second side surface in the X direction.

[0046] (Configuration and Effects of the Lighting Device) The above describes the configuration and light emission mechanism of the lighting device 1. Next, essential configurations and their functions and effects of the lighting device 1 of the present disclosure, as well as preferable configurations and their functions and effects will be described.

[0047] <Essential components and the effects derived from them> The lighting device 1 includes a light source 20 and a light guide plate 30 that is located on one side of the light source 20 in a first direction (Z direction), has an end surface 38 into which light projected from the light source 20 to one side in the Z direction is incident, and can define a thickness direction that is a second direction (X direction). The lighting device 1 also includes an integrated structure 45 that integrates the light guide plate 30 and the light source 20. The integrated structure 45 also has at least one of a Z-direction expansion / contraction absorption structure (first direction expansion / contraction absorption structure) 55 that can absorb expansion and contraction in the Z direction and prevent a clearance in the Z direction from occurring between the integrated structure 45 and the light guide plate 30, and an X-direction expansion / contraction absorption structure (second direction expansion / contraction absorption structure) 65 that can absorb expansion and contraction in the X direction and prevent a clearance in the X direction from occurring between the integrated structure 45 and the light guide plate 30.

[0048] This configuration can prevent at least one of the occurrence of a clearance in the Z direction between the integrated structure 45 and the light guide plate 30 and the occurrence of a clearance in the X direction between the integrated structure 45 and the light guide plate 30. Therefore, since the clearance can be reduced, it becomes easier to efficiently cause the light from the light source 20 to enter the light guide plate 30, and it becomes easier to increase the light utilization efficiency.

[0049] In addition, the clearance can be reduced and the variation in the positioning of the light source 20 and the light guide plate 30 can be reduced. From this viewpoint as well, the light utilization efficiency can be increased, and precise light distribution control can be easily performed, making it easier to emit the desired light.

[0050] In addition, since the Z-direction expansion / contraction absorbing structure 55 can prevent expansion / contraction in the Z-direction, when the Z-direction expansion / contraction absorbing structure 55 is provided, the fastening members that were conventionally required for positioning in the Z-direction can be omitted. In addition, since the X-direction expansion / contraction absorbing structure 65 can prevent expansion / contraction in the X-direction, when the X-direction expansion / contraction absorbing structure 65 is provided, the fastening members that were conventionally required for positioning in the X-direction can be omitted. Therefore, the number of parts can be reduced, and the manufacturing cost can be reduced. In addition, since the number of parts can be reduced, the man-hours required for assembling the lighting device 1 can be reduced, and not only can the lighting device 1 be easily assembled and disassembled, but also the stress of the assembly worker can be reduced.

[0051] Furthermore, since the number of parts can be reduced, the structure can be simplified and the occurrence of defects can be reduced. Also, since there is no need to provide through holes in the light guide plate 30 for inserting fastening members, the number of through holes can be reduced, which can reduce uneven light distribution caused by the reduced number of through holes.

[0052] <Several configurations that are preferable to adopt and the effects derived from each configuration> Next, a number of configurations that are preferably adopted and the effects derived from each of the configurations will be described. Note that each of the configurations described in this section does not necessarily have to be adopted.

[0053] The lighting device 1 may have a Z-direction expansion / contraction absorption structure 55. The Z-direction expansion / contraction absorption structure 55 may have one or more protruding parts 31 protruding in the X-direction from one side surface in the X-direction of the light guide plate 30, a horizontally extending surface (contact part) 51c that contacts an end part of the protruding part 31 on a first side (upper side) in the Z direction, and a Z-direction pressing part 57 that is flexible and presses an end part of the protruding part 31 on a second side (lower side) in the Z direction toward the horizontally extending surface 51c.

[0054] According to this configuration, the expansion and contraction in the Z direction can be absorbed by a simple mechanism.

[0055] Furthermore, the lighting device 1 may have an X-direction expansion / contraction absorbing structure 65. Furthermore, the X-direction expansion / contraction absorbing structure 65 may have a contact surface 81 that contacts a part of a surface of the light guide plate 30 on a first side in the X direction, and an X-direction pressing portion 67 that is flexible and presses a surface of the light guide plate 30 on a second side in the X direction toward the contact surface 81.

[0056] According to this configuration, the expansion and contraction in the X direction can be absorbed by a simple mechanism.

[0057] In the lighting device 1, the light source 20 may have a substrate 21 and an LED (light-emitting element) 29 mounted on the substrate 21. As in this embodiment, the Z direction, which is the first direction, and the X direction, which is the second direction, may be orthogonal. The substrate 21 may have a first edge 21a and a second edge 21b that are spaced apart in the X direction and extend substantially in a Y direction that is orthogonal to both the Z direction and the X direction. The integrated structure 45 may have a substrate abutment surface 76 that abuts against an end surface 21c of the first edge 21a, and a plurality of protrusions 56 that press an end surface 21d of the second edge 21b against the substrate abutment surface 76.

[0058] According to this configuration, by pressing the substrate 21 against the second member 70 using the multiple protrusions 56, the clearance in the X direction between the integrated structure 45 and the light source 20 can be reduced, and as a result, the light guide plate 30 can be precisely positioned in the X direction relative to the light source 20.

[0059] Furthermore, the light guide plate 30 may have a one-side protruding portion 39 that protrudes in the X direction from one side surface in the X direction. Furthermore, the integrated structure 45 may have a third through hole (insertion hole) 53 into which the one-side protruding portion 39 is inserted.

[0060] According to this configuration, the relative movement of the light guide plate 30 in the Y direction with respect to the first member 50 can be limited by engaging the one-side protrusion 39 with the third through hole 53. Therefore, the light guide plate 30 can be precisely positioned in the Y direction with respect to the integrated structure 45.

[0061] The integrated structure 45 may also include a first member 50 including a flexible engaging claw 62 and a second member 70 having an engaging recess 82 that engages with the engaging claw 62 .

[0062] According to this configuration, the integrated structure 45 can be configured without using any fastening members. Therefore, the number of parts can be significantly reduced, and the manufacturing cost can be significantly reduced. In addition, since the number of parts can be significantly reduced, the number of steps required for assembling the lighting device 1 can be significantly reduced, and not only can the assembly and disassembly of the lighting device 1 be significantly easier, but also the stress of the assembly worker can be significantly reduced. Furthermore, since the number of parts can be significantly reduced, the structure can be significantly simplified, and the possibility of defects can be significantly reduced.

[0063] The present disclosure is not limited to the above-described embodiment and its modified examples, and various improvements and modifications are possible within the scope of the claims of the present application and their equivalents.

[0064] For example, in the above embodiment, the lighting device 1 does not have a heat dissipation member. However, as will be described next, the lighting device may have a heat dissipation member. Fig. 19 is a diagram for explaining the structure of the upper part in the height direction of a lighting device 101 of a modified example, and is a diagram showing a cross section of a part of the upper part in the height direction.

[0065] 19, the lighting device 101 includes a light source 120, a light guide plate 130, an integrated structure 145, a heat transfer member 180, a heat dissipation sheet 185, and a heat dissipation plate 190. The integrated structure 145 has a first member 150 and a second member 170 that are integrated with each other by means such as a snap fit.

[0066] The light source 120 has a substrate 121 and a light emitting section 123 having a structure in which a plurality of LEDs are sealed with resin. A back surface 121a of the substrate 121 opposite to the side where the light emitting section is mounted is thermally connected to a heat sink 190 via a heat transfer member 180 and a heat dissipation sheet 185. The heat sink 190 may be disposed, for example, substantially parallel to a plane including the X direction and the Y direction. The light source 120 and the heat sink 190 are covered in the outer housing 140 and disposed in the outer housing 140. The heat sink 190 and the outer housing 140 are included in the housing 160. The heat transfer member 180 and the heat sink 190 are made of a metal material such as aluminum, iron, or copper, which has good heat transfer properties. The heat sink 190 has the same or higher heat dissipation properties as the outer housing 140.

[0067] Furthermore, the heat dissipation sheet 185 may be made of any known material, and may be a carbon fiber type heat dissipation sheet, a silicone type heat dissipation sheet, an acrylic type heat dissipation sheet, or may be made of a highly thermally conductive (low thermal resistance) material, for example, silicon filled with ceramic filler.

[0068] As described above, the lighting device 101 may include the light guide plate 130, the light source 120, the heat sink 190, and the outer housing 140 that covers the light source 120 and the heat sink 190, and the heat sink 190 may have the same or higher heat dissipation properties as the outer housing 140. With this configuration, the heat generated by the light source 120 can be efficiently dissipated to the outside via the heat sink 190. Therefore, the components that constitute the lighting device 101 can be prevented from thermally deteriorating. [Explanation of symbols]

[0069] 1,101 lighting device, 5 light source unit, 20,120 light source, 21,121 substrate, 21a first edge portion, 21b second edge portion, 21c end surface of first edge portion, 21d end surface of second edge portion, 29 LED, 30,130 light guide plate, 31 protrusion portion, 35 second side surface in X direction of light guide plate, 36 protrusion portion, 38 upper end surface in Z direction of light guide plate 30, 39 one-side protrusion portion, 45,145 integrated structure, 50,150 first member, 51 first through hole, 52 second through hole, 53 third through hole, 55 Z direction expansion contraction absorption structure, 56 protrusion, 57 Z direction pressing portion, 62 engagement claw 65 X direction expansion contraction absorption structure, 67 X direction pressing portion, 70, 170 second member, 75 Y-direction positioning structure, 76 substrate abutment surface, 80 reflector, 81 abutment surface, 82 engagement recess, 83 through hole, 84 engagement protrusion, 85 lower integrated member, 90 elastic heat dissipation member, 140 outer housing, 160 housing, 180 heat transfer member, 185 heat dissipation sheet, 190 heat sink.

Claims

1. A light source; a light guide plate having an end surface located on one side of the light source in a first direction and receiving light projected from the light source on the one side of the first direction, and capable of defining a thickness direction as a second direction; an integrated structure that integrates the light guide plate and the light source; the integrated structure has a first-direction expansion / contraction absorbing structure that can absorb expansion and contraction in the first direction and prevents a clearance from being generated in the first direction between the integrated structure and the light guide plate, but does not prevent a clearance from being generated in the second direction; The integrated structure and the first direction expansion / contraction absorbing structure are integrated together, The integrated structure is a long member that holds only one side end of the light guide plate in the first direction, and sandwiches at least a portion of the light source in the second direction.

2. A light source; a light guide plate having an end surface located on one side of the light source in a first direction and receiving light projected from the light source on the one side of the first direction, and capable of defining a thickness direction as a second direction; an integrated structure that integrates the light guide plate and the light source; the integrated structure has at least one of a first direction expansion / contraction absorbing structure capable of absorbing expansion and contraction in the first direction and preventing a clearance in the first direction from being generated between the integrated structure and the light guide plate, and a second direction expansion / contraction absorbing structure capable of absorbing expansion and contraction in the second direction and preventing a clearance in the second direction from being generated between the integrated structure and the light guide plate, The first direction expansion / contraction absorbing structure is provided. the first direction expansion / contraction absorption structure has one or more protruding portions protruding in the second direction from one side surface of the light guide plate in the second direction, a contact portion contacting an end portion of the protruding portion on a first side in the first direction, and a first direction pressing portion that is flexible and presses an end portion of the protruding portion on a second side in the first direction toward the contact portion.

3. A light source; a light guide plate having an end surface located on one side of the light source in a first direction and receiving light projected from the light source on the one side of the first direction, and capable of defining a thickness direction as a second direction; an integrated structure that integrates the light guide plate and the light source; the integrated structure has at least one of a first direction expansion / contraction absorbing structure capable of absorbing expansion and contraction in the first direction and preventing a clearance in the first direction from being generated between the integrated structure and the light guide plate, and a second direction expansion / contraction absorbing structure capable of absorbing expansion and contraction in the second direction and preventing a clearance in the second direction from being generated between the integrated structure and the light guide plate, the light source includes a substrate and a light emitting element mounted on the substrate; the first direction is perpendicular to the second direction, the substrate has first and second edges spaced apart in the second direction and extending generally in a third direction perpendicular to both the first and second directions; The integrated structure is a lighting device having a second member having a substrate abutment surface that abuts against an end surface of the first edge portion, and a first member different from the second member and having a plurality of protrusions that press the end surface of the second edge portion against the substrate abutment surface.

4. the light guide plate has a one-side protruding portion protruding in the second direction from one side surface in the second direction, The integrated structure has an insertion hole into which the one-side protrusion is inserted.

10. The lighting device of claim 1.

5. a light source, a heat sink, and an outer housing that covers the light source and the heat sink; The lighting device according to claim 1 , wherein the heat sink has a heat dissipation capability equal to or greater than that of the outer housing.

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