Lighting device

Abstract

To provide a lighting device capable of making a part corresponding to a curved part of a light guide body visible as a light-emitting part, and enhancing utilization efficiency of light emitted from a light source.SOLUTION: The lighting device includes a light source 2 and a rod-like light guide body 3, and the light guide body 3 has a curved part 8 in which a part of the light guide body 3 is curved between an incident part 4 and a light-emitting part 6, and a plate-like projection part 10 projected along the curved part 8 from the back side of the curved part 8. A part of light L emitted from a light source 2 is made incident on the inside of a projecting part 10 from an auxiliary incident part 11 provided on the projecting part 10, and the light L guided from the projecting part 10 toward the front side of a curved part 8 is emitted from the front side of the curved part 8 to the outside, so that an auxiliary light emitting part 12 provided on the front side of the curved part 8 is made to emit light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, lighting devices that combine a light source such as a light emitting diode (LED) with a rod-shaped light guide (light guide rod) have been known (see, for example, Patent Document 1 below).

[0003] In such lighting devices, light emitted from a light source enters the light guide through an incident section provided on the base end side of the light guide, and is guided toward the tip side of the light guide while repeatedly reflecting inside the light guide. Furthermore, light reflected by multiple reflection cutouts provided on the back side of the light guide is emitted from the front side of the light guide to the outside of the light guide. This allows the light-emitting section provided on the front side of the light guide to emit light in a line pattern.

[0004] In the rod-shaped light guide described above, for example, due to restrictions on the location of the light source, a curved portion is provided in which part of the light guide is curved between the incident portion and the light-emitting portion.

[0005] However, the curved portion is a non-light-emitting portion that guides the light incident from the incident portion toward the tip side of the light guide, and it is difficult to emit light from this curved portion toward the front side of the light guide and make the curved portion visible as a light-emitting portion.

[0006] To address this issue, the invention described in Patent Document 1 below provides a protrusion that protrudes from the front side of the curved portion toward the side opposite to the side where the light-emitting portion is located, and emits a portion of the light guided inside the curved portion from the front side of the protrusion to the outside, thereby causing the auxiliary light-emitting portion provided on the front side of the protrusion to emit light. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2023-44010 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the auxiliary light emitting unit is provided, a portion of the light guided inside the curved portion is guided toward the protruding portion, and therefore, of the light emitted from the light source, the light guided from the curved portion toward the tip side of the light guide is reduced, resulting in a decrease in the luminance of the light emitting unit. Furthermore, while it is possible to use a light source with a high output to compensate for the luminance of the light emitting unit and the auxiliary light emitting unit, this would increase costs.

[0009] The present invention has been proposed in consideration of the above-mentioned conventional circumstances, and aims to provide a lighting device that allows the portion corresponding to the curved portion of the light guide to be visually recognized as a light-emitting portion and that increases the utilization efficiency of light emitted from the light source. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides the following means. [1] An illumination device comprising a light source and a rod-shaped light guide, wherein light emitted from the light source is incident into the light guide from an incident portion provided on the base end side of the light guide, and the light is guided toward the tip side of the light guide, and light reflected by a plurality of reflection cutouts provided side by side on the back side of the light guide is emitted from the front side of the light guide to the outside of the light guide, thereby causing a light emitting portion provided on the front side of the light guide to emit light, the light guide has a curved portion between the incident portion and the light emitting portion, where a part of the light guide is curved, and a plate-like protruding portion protruding from a rear surface side of the curved portion along the curved portion, A lighting device characterized in that a portion of the light emitted from the light source is incident into the inside of the protrusion through an auxiliary incident portion provided in the protrusion, and the light guided from the protrusion toward the front side of the curved portion is emitted from the front side of the curved portion to the outside, thereby causing an auxiliary light emitting portion provided on the front side of the curved portion to emit light. [2] The auxiliary incident portion has a plurality of incident cuts arranged side by side along an end surface of the protrusion facing the light source, The lighting device described in [1] is characterized in that the incident cut includes a first cut surface onto which a portion of the light emitted from the light source is incident, and a second cut surface that reflects the light incident from the first cut surface toward the front side of the curved portion. [3] The lighting device according to [1], wherein the thickness of the protruding portion gradually increases from the base end side to the tip end side of the bending portion. [4] A plurality of light-emitting segments including the light source and the light guide, The lighting device described in [1], characterized in that the plurality of light-emitting segments have a structure in which the light-guiding bodies are sequentially connected to each other so that the light-emitting sections and the auxiliary light-emitting sections are arranged alternately. [5] The lighting device according to [4], wherein the thickness of the protrusions of the plurality of light-emitting segments gradually decreases in the direction of light travel from the auxiliary light-emitting section to the light-emitting section. [6] The lighting device according to [4], wherein the diameter of the entrance portion of the plurality of light-emitting segments gradually decreases in the direction of light travel from the auxiliary light-emitting portion toward the light-emitting portion. [7] The lighting device according to [4], wherein the diameter of the light guide of the plurality of light-emitting segments gradually decreases in the direction of light travel from the auxiliary light-emitting section to the light-emitting section. [Effects of the Invention]

[0011] As described above, according to the present invention, a lighting device is provided that makes it possible to visually recognize the portion corresponding to the curved portion of the light guide as a light-emitting portion and to increase the utilization efficiency of light emitted from the light source. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a plan view showing a configuration of an illumination device according to a first embodiment of the present invention. [Figure 2] 2 is an enlarged plan view of a main part of the lighting device shown in FIG. 1. FIG. [Figure 3] 3 is an enlarged plan view of a protrusion of a boxed area A shown in FIG. 2. FIG. [Figure 4] 3A is a cross-sectional view of the light guide taken along line BB in FIG. 2, and FIG. 3B is a cross-sectional view of the light guide taken along line CC in FIG. 2. [Figure 5] FIG. 10 is a plan view showing the configuration of an illumination device according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a plan view showing the configuration of an illumination device according to a third embodiment of the present invention. [Figure 7] FIG. 10 is a plan view showing the configuration of an illumination device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, the dimensions of the components may be shown at different scales to make them easier to see, and the dimensional ratios of the components may not necessarily be the same as in reality.

[0014] In addition, in the drawings shown below, an XYZ Cartesian coordinate system is set up, with the X-axis direction representing the front-to-back direction (length direction) of the lighting device, the Y-axis direction representing the left-to-right direction (width direction) of the lighting device, and the Z-axis direction representing the up-to-down direction (height direction) of the lighting device.

[0015] (First embodiment) First, as a first embodiment of the present invention, a lighting device 1A shown in, for example, FIGS. 1 to 4 will be described.

[0016] FIG. 1 is a plan view showing the configuration of the lighting device 1A. FIG. 2 is an enlarged plan view of a main part of the lighting device 1A shown in FIG. 1. FIG. 3 is an enlarged plan view of the protrusion 10 of the enclosed part A shown in FIG. 2. FIG. 4(A) is a cross-sectional view of the light guide 3 taken along the line segment BB shown in FIG. 2. FIG. 4(B) is a cross-sectional view of the light guide 3 taken along the line segment CC shown in FIG. 2.

[0017] 1 and 2, the lighting device 1A of this embodiment includes a light source 2 and a rod-shaped light guide 3. In the lighting device 1A of this embodiment, light L emitted from the light source 2 enters the light guide 3 from an incident portion 4 provided on the base end side of the light guide 3 and is guided toward the tip side of the light guide 3. At the same time, the light L reflected by a plurality of reflection cutouts 5 provided on the back side of the light guide 3 is emitted from the front side of the light guide 3 to the outside of the light guide 3.

[0018] As a result, in the lighting device 1A of this embodiment, it is possible to make the light emitting section 6 provided on the front side of the light guide 3 emit light in a line shape.

[0019] The light source 2 is formed of a light emitting element such as an LED, and is mounted on the surface of the circuit board 7. The light source 2 faces the base end side of the light guide 3 and emits light L radially toward the incident portion 4 in front of it.

[0020] The light guide 3 is made of a light-transmitting material such as a transparent resin such as polycarbonate or acrylic, or glass. The light guide 3 has, for example, a substantially circular vertical cross section and an elongated shape extending in the vehicle width direction.

[0021] The incident portion 4 is located on the base end side of the light guide 3 and has a flat (planar) incident surface 4a facing the light source 2. At the incident portion 4, light L emitted from the light source 2 is incident from this incident surface 4a into the light guide 3. As a result, the light L incident from the incident surface 4a is guided toward the tip side of the light guide 3 while repeatedly reflecting inside the light guide 3.

[0022] The multiple reflection cuts 5 need only reflect light L incident on the back side of the light guide 3 at an angle that causes it to exit (transmit) from the front side of the light guide 3 to the outside, and there are no particular limitations on their shape, size, number, etc.

[0023] For example, the reflection cut 5 in this embodiment is configured by cutting out a central portion on the back side of the light guide 3 in a vertical direction (in this embodiment, the up-and-down direction of the lighting device 1A) perpendicular to the axial direction of the light guide 3, and arranging groove portions with approximately triangular cross sections in the axial direction of the light guide 3 (in this embodiment, the left-right direction of the lighting device 1A).

[0024] Furthermore, in order to make the light-emitting section 6 emit light more uniformly in the axial direction of the light guide 3, the spacing between adjacent grooves forming the reflection cuts 5 may gradually narrow from the base end side to the tip end side of the light guide 3, or the depth of the grooves forming the reflection cuts 5 may gradually deepen.

[0025] Furthermore, the light guide 3 may be configured to have a pair of reflective surfaces (not shown) on both sides of the multiple reflective cuts 5 on the back side, which reflect light L guided inside the light guide 3 toward the front side of the light guide 3.

[0026] The light emitting unit 6 is located on the front side of the light guide 3 and has an emission surface 6a that is continuous in the axial direction of the light guide 3. The emission surface 6a is configured as a convex curved surface that is curved in an arc shape in the vertical cross section of the light guide 3. As a result, the light emitting unit 6 emits light L from this emission surface 6a to the outside of the light guide 3, thereby emitting light in a line shape.

[0027] The light exit surface 6a may be provided with a plurality of diffusion cuts (not shown) for diffusing the light L emitted from the light exit surface 6a. Examples of diffusion cuts include lens cuts called flute cuts or fisheye cuts, and uneven structures formed by knurling or embossing. The degree of diffusion of the light L emitted from the light exit surface 6a can be controlled by adjusting the shape of the diffusion cuts. Alternatively, a diffusion lens may be disposed on the front side of the light guide 3 to diffuse the light L emitted from the light exit surface 6a.

[0028] In the lighting device 1A of this embodiment, the light guide 3 has a curved portion 8 that is partially curved between the incident portion 4 and the light-emitting portion 6, and an extended portion 9 that is provided with a plurality of reflection cuts 5 and the light-emitting portion 6. That is, the light guide 3 extends forward from a position facing the light source 2, is curved by the curved portion 8, and then has an elongated shape with the extended portion 9 extending in the left-right direction.

[0029] 2, the light guide 3 has a plate-shaped protruding portion 10 that protrudes from the rear side of the curved portion 8 along the curved portion 8. The protruding portion 10 has a thickness smaller than the diameter of the curved portion 8, and is provided protruding from the center of the rear side of the curved portion 8.

[0030] Furthermore, end face 10a of protrusion 10 on the side facing the light source (rear side) is extended from a position continuous with incident surface 4a in a direction parallel to extension 9 (left-right direction). On the other hand, end face 10b of protrusion 10 on the side adjacent to end face 10a on the rear side (side surface side) is extended from the boundary between curved portion 8 and extension 9 in a direction perpendicular to extension 9 (front-rear direction).

[0031] In the lighting device 1A of this embodiment, of the light L radially emitted from the light source 2, a portion of the light L' that is emitted in a wider angle direction than the range of incidence on the incident surface 4a is incident into the inside of the protrusion 10 through an auxiliary incident portion 11 provided in the protrusion 10.

[0032] 2 and 3, the auxiliary incident portion 11 has a plurality of incident cutouts 11a arranged side by side along the end face 10a on the rear side of the protrusion 10. The incident cutouts 11a are configured, for example, by cutting out the end face 10a on the rear side of the protrusion 10 in the thickness direction (up-down direction) to form grooves with a generally triangular cross section that are arranged side by side in the width direction (left-right direction) of the protrusion 10.

[0033] Each incident cut 11a includes a first cut surface 11b onto which a portion of the light L' emitted from the light source 2 is incident, and a second cut surface 11c that reflects the light L' incident from the first cut surface 11b toward the front side of the curved portion 8. In each incident cut 11a, the reflection angle of the light L' reflected by the second cut surface 11c is adjusted according to the incident angle of the light L' incident on the respective first cut surface 11b.

[0034] As a result, the light L′ incident from the auxiliary incident portion 11 is guided inside the protruding portion 10 toward the front side of the curved portion 8.

[0035] In the lighting device 1A of this embodiment, light L' guided from the protrusion 10 toward the front side of the curved portion 8 is emitted to the outside from the front side of the curved portion 8, causing the auxiliary light-emitting portion 12 provided on the front side of the curved portion 8 with a width corresponding to the protrusion 10 to emit light.

[0036] The auxiliary light emitting unit 12 is located on the front side of the curved portion 8 and has an auxiliary light emitting surface 12a that is continuous in the axial direction of the curved portion 8. The auxiliary light emitting surface 12a is configured as a convex curved surface that is curved in an arc shape in the vertical cross section of the curved portion 8.

[0037] The auxiliary exit surface 12a may be provided with a plurality of diffusion cuts (not shown) for diffusing the light L emitted from the auxiliary exit surface 12a, similar to the exit surface 6a.

[0038] As a result, the auxiliary light emitting unit 12 emits light L' from the auxiliary emission surface 12a to the outside of the curved portion 8, and thereby emits light in a continuous line on the emission surface 6a of the light emitting unit 6.

[0039] Also, in the lighting device 1A of the present embodiment, as shown in FIGS. 2 and 4(A) and (B), the thicknesses (t1, t2) of the protruding portions 10 gradually increase from the proximal end side to the distal end side of the curved portion 8 (t1 < t2). Thereby, it is possible to cause the auxiliary light emitting portion 12 to emit light more uniformly in the axial direction of the curved portion 8.

[0040] That is, a part of the light L' emitted from the light source 2 in the wide-angle direction has a smaller light quantity as the angle widens. On the other hand, the larger the thickness of the protruding portion 10, the more light L' can be made to enter from the auxiliary entrance portion 11 into the inside of the protruding portion 10. Thereby, it is possible to make the light L' incident from the auxiliary entrance portion 11 more uniform in the width direction of the protruding portion 10.

[0041] In the lighting device 1A of the present embodiment having the above-described configuration, the auxiliary light emitting portion 12 provided on the front side of the curved portion 8 described above can be visually recognized as a continuous light emitting portion with the main light emitting portion 6 provided on the front side of the extension portion 9.

[0042] Also, in the lighting device 1A of the present embodiment, among the light L emitted from the light source 2, apart from the light L incident from the entrance portion 4, a part of the light L' emitted in a wider angle direction than the entrance portion 4 is used to cause the above-described auxiliary light emitting portion 12 to emit light. Thereby, it is possible to further improve the utilization efficiency of the light L emitted from the light source 2.

[0043] (Second Embodiment) Next, as a second embodiment of the present invention, for example, a lighting device 1B shown in FIG. 5 will be described.

[0044] Note that FIG. 5 is a plan view showing the configuration of the lighting device 1B. Also, in the following description, for parts equivalent to those of the lighting device 1A described above, the description will be omitted and the same reference numerals will be used in the drawings.

[0045] As shown in FIG. 5, the lighting device 1B of this embodiment includes a plurality of (four in this embodiment) light emitting segments 20, each including the light source 2 and the light guide 3 that constitute the lighting device 1A.

[0046] The plurality of light emitting segments 20 have a structure in which the light guides 3 are connected to one another in order so that the light emitting portions 6 and the auxiliary light emitting portions 12 are arranged alternately in the vehicle width direction.

[0047] The connection position of adjacent light guides 3 is located at the boundary between the curved portion 8 and the extended portion 9. The curved portion 8 at this connection position is connected to the extended portion 9 located upstream in the traveling direction of the light L. Therefore, the auxiliary light-emitting portion 12 at the connection position is provided on the front side of the extended portion 9 to which the curved portion 8 is connected, with a width corresponding to the protrusion 10.

[0048] The light sources 2 constituting the plurality of light emitting segments 20 are arranged side by side on the same surface of the same circuit board 7 .

[0049] In the lighting device 1B of this embodiment having the above-described configuration, the light emitting unit 6 and the auxiliary light emitting unit 12, which are configured from the above-described plurality of light emitting segments 20, can be visually recognized as a continuous light emitting unit.

[0050] Furthermore, in the lighting device 1B of this embodiment, it is possible to perform light effects while changing the color tone and brightness of the light-emitting unit 6 and the auxiliary light-emitting unit 12 by changing the color of light emitted from each light source 2 of the above-mentioned plurality of light-emitting segments 20 or by changing the output power of light emitted from each light source 2. It is also possible to perform light movement effects by sequentially switching on and off each light source 2 of the plurality of light-emitting segments 20.

[0051] In the lighting device 1B of this embodiment, in order to make the light-emitting section 6 and the auxiliary light-emitting section 12, which are composed of a plurality of light-emitting segments 20, emit light more uniformly, it is preferable to gradually reduce the thickness of the protrusion 10 in the traveling direction of the light L from the auxiliary light-emitting section 12 toward the light-emitting section 6. It is also preferable to gradually reduce the diameter of the incident section 4 in the traveling direction of the light L. It is also preferable to gradually reduce the diameter of the light guide 3 in the traveling direction of the light L.

[0052] That is, in this lighting device 1B, the light L emitted from each light source 2 is converged into each extension portion 9 through each curved portion 8 of the multiple light-emitting segments 20, so that the amount of light increases in the direction in which the converged light L travels.

[0053] In response to this, by sequentially changing the thickness of the protrusion 10, the diameter of the incident portion 4, and the diameter of the light guide 3 among the above-mentioned plurality of light-emitting segments 20, it is possible to sequentially reduce the amount of light L that converges from each light source 2 to each extension portion 9 via each curved portion 8. This makes it possible to make the light-emitting portion 6 and the auxiliary light-emitting portion 12, which are composed of the plurality of light-emitting segments 20, emit light more uniformly.

[0054] (Third embodiment) Next, as a third embodiment of the present invention, an illumination device 1C shown in FIG. 6 will be described.

[0055] 6 is a plan view showing the configuration of the lighting device 1C. In the following description, the same components as those in the lighting devices 1A and 1B will not be described and will be denoted by the same reference numerals in the drawings.

[0056] As shown in Figure 6, the lighting device 1C of this embodiment has a configuration in which multiple light-emitting segments 20 that make up the lighting device 1B are arranged in opposite directions to each other, and the tip sides of the extension portions 9 of the light guides 3 are connected between them.

[0057] Furthermore, in the lighting device 1C of this embodiment, in order to make the light-emitting unit 6 and the auxiliary light-emitting unit 12, which are composed of a plurality of light-emitting segments 20, emit light more uniformly, the thickness of the protrusion 10 gradually decreases in the traveling direction of the light L from the auxiliary light-emitting unit 12 toward the light-emitting unit 6. Also, the diameter of the incident portion 4 gradually decreases in the traveling direction of the light L. Furthermore, the diameters of the curved portion 8 and the extended portion 9 of the light guide 3 gradually decrease in the traveling direction of the light L.

[0058] In the lighting device 1C of this embodiment having the above-described configuration, the light emitting unit 6 and the auxiliary light emitting unit 12, which are configured from the above-described plurality of light emitting segments 20, can be visually recognized as a continuous light emitting unit.

[0059] Furthermore, in the lighting device 1C of this embodiment, it is possible to produce effects of the light L while changing the color tone and brightness of the light-emitting unit 6 and the auxiliary light-emitting unit 12 by changing the color of the light L emitted from each light source 2 of the above-mentioned plurality of light-emitting segments 20 or by changing the output power of the light L emitted from each light source 2. It is also possible to produce effects of the movement of the light L by sequentially switching on and off each light source 2 of the plurality of light-emitting segments 20.

[0060] (Fourth embodiment) Next, as a fourth embodiment of the present invention, an illumination device 1D shown in FIG. 7 will be described.

[0061] 7 is a plan view showing the configuration of the lighting device 1D. In the following description, the same parts as those in the lighting device 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0062] 7, the lighting device 1D of this embodiment has a configuration in which the light guide 3 constituting the lighting device 1A is branched via a branch portion 3a into a pair of curved portions 8 and an extension portion 9 that are directed in opposite directions. The light guide 3 also has a pair of protrusions 10 that protrude from the back sides of the pair of curved portions 8 along the curved portions 8.

[0063] In the lighting device 1B of this embodiment having the above-mentioned configuration, in a configuration in which the above-mentioned light guide 3 is branched via the branching portion 3a, the auxiliary light emitting portion 12 provided on the front side of the pair of curved portions 8 can be visually recognized as a light emitting portion continuous with the main light emitting portion 6 provided on the front side of the extension portion 9.

[0064] Furthermore, in the lighting device 1D of this embodiment, apart from the light L emitted from the light source 2 and incident from the incident portion 4, a portion of light L' emitted in a wider angle direction than the incident portion 4 can be used to cause the above-mentioned auxiliary light emitting portion 12 to emit light. This makes it possible to further increase the utilization efficiency of the light L emitted from the light source 2.

[0065] The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the lighting devices 1A to 1D, the shape of the light guide 3 can be changed as appropriate to suit the design of the actual vehicle.

[0066] Furthermore, in the above-mentioned lighting devices 1A to 1D, the light L' that enters the inside of the protrusion 10 through the plurality of incident cuts 11a provided on the end face 10a on the back side of the protrusion 10 is guided toward the front side of the curved portion 8, but the present invention is not necessarily limited to such a configuration.

[0067] For example, it is possible to configure the projection 10 so that the light L' incident from the rear end face 10a thereof is reflected toward the front side of the curved portion 8 via a plurality of reflective cuts (not shown) provided on the side end face 10b of the projection 10. In addition, the shapes and angles of the rear and side end faces 10a, 10b of the projection 10 can be changed as appropriate to suit such a configuration.

[0068] Specific applications of the lighting device to which the present invention is applied include, for example, vehicle lighting fixtures, in-vehicle lighting, lighting for gaming machines, lighting for toys, signboard lighting, general lighting, and a wide range of other applications. [Explanation of symbols]

[0069] 1A, 1B, 1C, 1D... Illumination device 2... Light source 3... Light guide 4... Incident part 5... Reflection cut 6... Light emitting part 7... Circuit board 8... Curved part 9... Extension part 10... Protruding part 11... Auxiliary incident part 12... Auxiliary light emitting part L, L'... Light

Claims

1. An illumination device comprising a light source and a rod-shaped light guide, wherein light emitted from the light source is incident into the light guide from an incident portion provided on a base end side of the light guide and guided toward a tip side of the light guide, and light reflected by a plurality of reflection cutouts provided side by side on a back side of the light guide is emitted from a front side of the light guide to the outside of the light guide, thereby causing a light emitting portion provided on the front side of the light guide to emit light, the light guide has a curved portion between the incident portion and the light emitting portion, where a part of the light guide is curved, and a plate-like protruding portion protruding from a rear surface side of the curved portion along the curved portion, A lighting device characterized in that a portion of the light emitted from the light source is incident into the inside of the protrusion through an auxiliary incident portion provided in the protrusion, and the light guided from the protrusion toward the front side of the curved portion is emitted from the front side of the curved portion to the outside, thereby causing an auxiliary light emitting portion provided on the front side of the curved portion to emit light.

2. the auxiliary incident portion has a plurality of incident cuts arranged side by side along an end surface of the protrusion on a side facing the light source, 2. The lighting device according to claim 1, wherein the incident cut includes a first cut surface onto which a portion of the light emitted from the light source is incident, and a second cut surface that reflects the light incident from the first cut surface toward a front side of the curved portion.

3. 2. The lighting device according to claim 1, wherein the thickness of the protruding portion gradually increases from the base end side of the bending portion toward the tip end side.

4. a plurality of light emitting segments each including the light source and the light guide; 2. The lighting device according to claim 1, wherein the plurality of light-emitting segments have a structure in which the light guides are connected to each other in sequence so that the light-emitting portions and the auxiliary light-emitting portions are arranged alternately.

5. 5. The lighting device according to claim 4, wherein the thickness of the protrusions of the plurality of light-emitting segments gradually decreases in the direction of travel of light from the auxiliary light-emitting section toward the light-emitting section.

6. 5. The lighting device according to claim 4, wherein the diameter of the entrance portion of each of the plurality of light-emitting segments gradually decreases in the direction of travel of light from the auxiliary light-emitting portion toward the light-emitting portion.

7. 5. The lighting device according to claim 4, wherein the diameter of the light guide of each of the plurality of light emitting segments gradually decreases in the direction of travel of light from the auxiliary light emitting section toward the light emitting section.

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