Vehicular lighting fixture

Abstract

To provide a vehicular lighting fixture capable of suppressing light emission unevenness of a tabular light guide body.SOLUTION: A vehicular lighting fixture 1 includes: a first light source 20; a columnar light guide body 40 for guiding light from the first light source 20 from one end side toward the other end side; and a tabular light guide body 50 connected to the columnar light guide body 40. The columnar light guide body 40 includes a plurality of steps 45 arranged side by side in the longer direction of the columnar light guide body 40 on the opposite side from the side to which the tabular light guide body 50 is connected out of an outer peripheral surface. The step 45 includes: a first inclined surface 46 inclined toward the opposite side from the tabular light guide body 50 side from the one end side toward the other end side; and a second inclined surface 47 positioned further on the other end side than the first inclined surface 46 and inclined to the tabular light guide body 50 side from the one end side toward the other end side. The tabular light guide body 50 emits light L1 that is guided from the columnar light guide body 40 from a main surface 50 s1, and an inclination α with respect to the longer direction of the columnar light guide body 40 of the second inclined surface 47 in the step 45 positioned on the one end side is larger than the inclination α of the second inclined surface 47 in the step 45 positioned on the other end side.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a vehicle lamp. [Background technology]

[0002] 2. Description of the Related Art There are vehicle lamps that include a light source and a light guide that guides light from the light source, and Patent Document 1 below discloses such a vehicle lamp.

[0003] In the vehicle lamp of the following Patent Document 1, the light guide is composed of a columnar light guide and a plate-shaped light guide connected to the outer peripheral surface of the columnar light guide so that the in-plane direction of one of the main surfaces is along the longitudinal direction of the columnar light guide. Light from the light source enters the columnar light guide from one end face of the columnar light guide and propagates through the columnar light guide. The columnar light guide includes a plurality of steps arranged along the extending direction of the columnar light guide on the side of the outer peripheral surface opposite to the side to which the plate-shaped light guide is connected. The plurality of steps are formed to have the same shape, and the light from the light source is internally reflected toward the plate-shaped light guide and guided to the plate-shaped light guide. The plate-shaped light guide emits the light guided from the columnar light guide from one main surface. Therefore, the light from the light source is guided from the columnar light guide to the plate-shaped light guide and is emitted from one main surface of the plate-shaped light guide, and when the plate-shaped light guide is viewed from one main surface, the plate-shaped light guide appears to emit light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-147105 A Summary of the Invention [Problem to be solved by the invention]

[0005] A light guide composed of such a columnar light guide and a plate-shaped light guide tends to have difficulty in guiding light to the portion of the plate-shaped light guide on the light source side, and there is a concern that unevenness will occur in the light emission of the plate-shaped light guide.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a vehicle lamp capable of suppressing uneven light emission from a plate-shaped light guide. [Means for solving the problem]

[0007] In order to achieve the above object, a vehicle lamp of the present invention includes a light source, a columnar light guide that guides light from the light source incident through an incident portion at one end side toward the other end side, and a plate-shaped light guide connected to an outer circumferential surface of the columnar light guide such that an in-plane direction of one main surface is along a longitudinal direction of the columnar light guide, the columnar light guide including a plurality of steps arranged along the longitudinal direction of the columnar light guide on a side of the outer circumferential surface opposite to a side to which the plate-shaped light guide is connected, the steps being inclined from the one end side toward the other end side toward the opposite side to the plate-shaped light guide. the plate-shaped light guide has a first inclined surface which is inclined toward the plate-shaped light guide from the one end side to the other end side, and a second inclined surface which is located on the other end side of the first inclined surface and inclined toward the plate-shaped light guide from the one end side to the other end side and internally reflects light from the light source toward the plate-shaped light guide, wherein the plate-shaped light guide emits light guided from the columnar light guide from one of the main surfaces, and the inclination of the second inclined surface at the step located on the one end side with respect to the longitudinal direction of the columnar light guide is greater than the inclination of the second inclined surface at the step located on the other end side with respect to the longitudinal direction of the columnar light guide.

[0008] In this vehicle lamp, the angle of incidence of the light propagating through the columnar light guide on the second inclined surface may be smaller in the step located on one end side than in the step located on the other end side. Therefore, in the step located on the one end side, the light may be emitted from the second inclined surface, and the light may be incident on the first inclined surface of the adjacent step and internally reflected on the second inclined surface of the adjacent step. In this case, the light is refracted at the second inclined surface and the first inclined surface of the adjacent step, so that the propagation direction of the light when it is incident on the second inclined surface of the adjacent step may be made closer to the longitudinal direction of the columnar light guide. Therefore, the light internally reflected on the second inclined surface of the adjacent step may be propagated in a direction perpendicular to the longitudinal direction of the columnar light guide or in a direction toward the one end side based on the direction perpendicular to the longitudinal direction of the columnar light guide. Therefore, according to this vehicle lamp, the inclination of the second inclined surface in each step is the same, and light can be more easily guided to the portion of the plate-shaped light guide on the light source side than when the light is not emitted from the second inclined surface but is internally reflected by the second inclined surface. Also, in the step located on the other end side, light can be internally reflected by the second inclined surface without being emitted from the second inclined surface and propagated in a direction toward the other end side based on a direction perpendicular to the longitudinal direction of the columnar light guide. Therefore, according to this vehicle lamp, light emission unevenness of the plate-shaped light guide can be suppressed compared to the above case.

[0009] The second inclined surface of the step closer to the one end may have a greater inclination with respect to the longitudinal direction of the columnar light guide.

[0010] With this configuration, unevenness in the light emission of the plate-shaped light guide can be further suppressed.

[0011] The inclination of the first inclined surface of each of the steps with respect to the longitudinal direction of the columnar light guide may be the same.

[0012] Such a configuration can facilitate the design of the steps.

[0013] The width of the second inclined surface of the step located on the other end side in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-shaped light guide may be wider than the width of the second inclined surface of the step located on the one end side in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-shaped light guide.

[0014] The amount of light propagating through the columnar light guide tends to decrease as it gets farther from one end, i.e. closer to the other end. Therefore, the amount of light internally reflected by the second inclined surface of the step located at the other end tends to be less than the amount of light internally reflected by the second inclined surface of the step located at the one end. Therefore, according to this vehicle lamp, the difference between the amount of light directed from the step located at the other end to the portion of the plate-shaped light guide opposite to the light source side and the amount of light directed from the step located at the one end to the portion of the plate-shaped light guide on the light source side can be made smaller than when the widths of the second inclined surfaces of the steps are the same. Therefore, according to this vehicle lamp, the unevenness of the light emission of the plate-shaped light guide can be suppressed compared to the above case.

[0015] In this case, the second inclined surface of the step closer to the other end may have a wider width in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-shaped light guide.

[0016] With this configuration, unevenness in the light emission of the plate-shaped light guide can be further suppressed.

[0017] The step closest to the one end may be located closer to the one end than an end of the connection portion between the columnar light guide and the plate-shaped light guide on the one end side.

[0018] With this configuration, it is possible to prevent light from being difficultly guided to the portion of the plate-shaped light guide on the light source side, compared to when the step closest to one end is located closer to the other end than the end of the one end of the above-mentioned connection portion.

[0019] The step closest to the other end may be located closer to the other end than an end of the connection portion between the columnar light guide and the plate-shaped light guide on the other end side.

[0020] With this configuration, it is possible to prevent light from being difficultly guided to the part of the plate-shaped light guide opposite the light source side, compared to when the step closest to the other end is located closer to one end than the other end of the connection portion. Effect of the Invention

[0021] As described above, according to the present invention, a vehicle lamp capable of suppressing uneven light emission from a plate-shaped light guide can be provided. [Brief description of the drawings]

[0022] [Figure 1] 1 is a plan view showing a vehicle lamp according to an embodiment of the present invention; [Diagram 2] 2 is a cross-sectional view of the vehicular lamp taken along line II-II in FIG. 1. [Diagram 3] 13 is a diagram of the first light guide as viewed from the rear side along a direction parallel to the right end face of the columnar light guide. FIG. [Figure 4] 4 is a cross-sectional view of a first light guide taken along a longitudinal direction of the columnar light guide and crossing a step located on one end side of the columnar light guide. FIG. [Diagram 5] 10 is a cross-sectional view of a first light guide taken along a longitudinal direction of the columnar light guide and crossing a step located on the other end side of the columnar light guide. FIG. [Figure 6] FIG. 4 is a cross-sectional view of a second plate-shaped portion. [Figure 7] 5 is a diagram similar to FIG. 4 showing a first light guide in a modified example. FIG. [Figure 8] 6 is a diagram similar to FIG. 5 showing a first light guide in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A preferred embodiment of the vehicle lamp according to the present invention will be described in detail below with reference to the drawings. The embodiments exemplified below are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit of the present invention. In addition, the components in the embodiments exemplified below may be appropriately combined in the present invention. In addition, in the drawings referred to below, the dimensions of each member may be changed in order to facilitate understanding. In addition, in the drawings, for ease of viewing, reference symbols may be given to only some of the similar components, and some reference symbols may be omitted.

[0024] FIG. 1 is a plan view showing a vehicle lamp according to an embodiment of the present invention. The vehicle lamp 1 according to this embodiment is a combination lamp for a four-wheeled motor vehicle having a tail lamp function and a stop lamp function. Such combination lamps are generally provided on the left and right sides of the rear of the vehicle. In this specification, "right" means the right side in the forward direction of the vehicle, and "left" means the left side in the forward direction of the vehicle. The left and right combination lamps have the same configuration, except that their shapes are roughly symmetrical in the left and right directions. For this reason, the vehicle lamp 1, which is the right combination lamp, will be described below. In FIG. 1, the upper side is the front side of the vehicle, and the lower side is the rear side of the vehicle.

[0025] As shown in FIG. 1, the vehicle lamp 1 of this embodiment mainly comprises a housing 10, a first light source 20, a first light guide 30 that guides light from the first light source 20, a second light source 60, and a second light guide 70 that guides light from the second light source 60.

[0026] 1, the housing 10 is shown in horizontal cross section. The housing 10 has a lamp housing 11 and an outer cover 12 having optical transparency. The lamp housing 11 has an opening from the rear to the right side, and the outer cover 12 is fixed to the lamp housing 11 so as to close the opening. A first light source 20, a first light guide 30, a second light source 60, and a second light guide 70 are accommodated in a space R formed by the lamp housing 11 and the outer cover 12.

[0027] The first light source 20 of the present embodiment includes a light emitting element 21 that emits red light when the headlights of the vehicle are turned on. The light emitting element 21 of the present embodiment is an LED (Light Emitting Diode), but is not limited thereto.

[0028] FIG. 2 is a cross-sectional view of the vehicle lamp 1 taken along line II-II in FIG. 1. In FIG. 2, the right side is the front side of the vehicle, the left side is the rear side of the vehicle, and the housing 10 is omitted. As shown in FIGS. 1 and 2, the first light guide 30 of this embodiment includes a columnar light guide 40 and a plate-shaped light guide 50. The columnar light guide 40 of this embodiment is a translucent cylindrical member that extends from the right rear part in the space R diagonally toward the left rear and is curved so as to be convex toward the rear side. A right end surface 41, which is one end of the columnar light guide 40, is a flat surface that is approximately perpendicular to the longitudinal direction of the columnar light guide 40. The first light source 20 is disposed so that a light emission surface 21s that emits light from the light emitting element 21 faces the right end surface 41, and the light L1 from the first light source 20 enters the columnar light guide 40 from the right end surface 41. That is, the right end face 41 is an incident portion into which the light L1 from the first light source 20 is incident. The columnar light guide 40 guides the light L1 incident from the right end face 41 toward the left end side, which is the other end side. In this embodiment, the left end face 42, which is the other end of the columnar light guide 40, is a hemispherical curved surface. Therefore, compared to a case in which the left end face 42 is a flat surface approximately perpendicular to the longitudinal direction of the columnar light guide 40, it is possible to suppress the light incident on the columnar light guide 40 from emitting from the left end face 42.

[0029] The plate-shaped light guide 50 is a plate-shaped member having translucency, and is connected to the outer peripheral surface of the columnar light guide 40 such that the in-plane direction of one of the main surfaces 50s1 is along the longitudinal direction of the columnar light guide 40, and guides the light L1 propagating through the columnar light guide 40. In this embodiment, the plate-shaped light guide 50 is connected to the rear side of the outer peripheral surface of the columnar light guide 40. The plate-shaped light guide 50 also includes a flat first plate-shaped portion 51 extending rearward from the columnar light guide 40, a flat second plate-shaped portion 52 extending obliquely downward rearward from the vicinity of the rear end of the first plate-shaped portion 51, and a connection portion 53 connecting the rear end of the first plate-shaped portion 51 and the upper end of the second plate-shaped portion 52. One main surface 50s1 of the plate-shaped light guide 50 is made up of the upper main surface 51s1 of the first plate-shaped portion 51, the rear main surface 52s1 of the second plate-shaped portion 52, and a main surface 53s1 of the connection portion 53 connecting the main surface 51s1 and the main surface 52s1. The other main surface 50s2 of the plate-shaped light guide 50 is made up of the lower main surface 51s2 of the first plate-shaped portion 51, the front main surface 52s2 of the second plate-shaped portion 52, and a main surface 53s2 of the connection portion 53 connecting the main surface 51s2 and the main surface 52s2. The radius of curvature of the main surface 53s1 of the connection portion 53 is greater than the radius of curvature of the main surface 53s2 of the connection portion 53.

[0030] Examples of materials constituting the columnar light guide 40 and the plate-like light guide 50 include transparent resin, glass, etc. In this embodiment, the columnar light guide 40 and the plate-like light guide 50 are made of the same colorless and transparent resin, and the columnar light guide 40 and the plate-like light guide 50 are integral with each other.

[0031] Fig. 3 is a view of the first light guide 30 as viewed from the rear side along a direction parallel to the right end face 41 of the columnar light guide 40. As shown in Fig. 3, the columnar light guide 40 includes a plurality of steps 45 arranged along the longitudinal direction of the columnar light guide 40 on the rear side of the outer circumferential surface, which is opposite to the side to which the plate-like light guide 50 is connected. Note that in Fig. 3, a reference numeral is attached to one step 45, and reference numerals of the other steps 45 are omitted.

[0032] Fig. 4 is a cross-sectional view of the first light guide 30 taken along the longitudinal direction of the columnar light guide 40 and crossing the step 45 located on the right end side, which is one end side of the columnar light guide 40. Fig. 5 is a cross-sectional view of the first light guide 30 taken along the longitudinal direction of the columnar light guide 40 and crossing the step 45 located on the left end side, which is the other end side of the columnar light guide 40.

[0033] As shown in FIG. 4 and FIG. 5, each step 45 has a first inclined surface 46 and a second inclined surface 47. The first inclined surface 46 is a surface that inclines from the right end side to the left end side toward the opposite side to the plate-shaped light guide 50 side. The second inclined surface 47 is a surface located on the left end side of the first inclined surface 46 and inclined from the right end side to the left end side toward the plate-shaped light guide 50 side. Although details will be described later, the second inclined surface 47 internally reflects the light L1 propagating through the columnar light guide 40 from the right end side to the left end side toward the plate-shaped light guide 50. In this embodiment, the first inclined surface 46 and the second inclined surface 47 are flat surfaces, and the edge on the left end side of the first inclined surface 46 is connected to the edge on the right end side of the second inclined surface 47. For this reason, in this embodiment, the step 45 is a triangular prism-shaped protrusion extending in a direction approximately perpendicular to the longitudinal direction of the columnar light guide 40, and is formed, for example, by providing a recess on the outer circumferential surface of the columnar light guide 40. Note that the step 45 only needs to have a first inclined surface 46 and a second inclined surface 47, and may be, for example, a quadrangular prism-shaped protrusion in which the left edge of the first inclined surface 46 and the right edge of the second inclined surface 47 are spaced apart from each other. Alternatively, the step 45 may be a protrusion protruding from the outer circumferential surface of the columnar light guide 40.

[0034] The inclination α of the second inclined surface 47 of the step 45 located on the right end side with respect to the longitudinal direction of the columnar light guide 40 is larger than the inclination α of the second inclined surface 47 of the step 45 located on the left end side with respect to the longitudinal direction of the columnar light guide 40. In this embodiment, the inclination α is larger for the second inclined surface 47 of the step 45 located on the right end side. Moreover, the width 47w1 of the second inclined surface 47 of the step 45 located on the left end side in the direction perpendicular to the longitudinal direction of the columnar light guide 40 and toward the plate-like light guide 50 side is wider than the above-mentioned width 47w1 of the second inclined surface 47 of the step 45 located on the right end side. Moreover, the second inclined surface 47 of the step 45 located on the left end side has a wider width 47w1. Moreover, the inclination β of the first inclined surface 46 of each step 45 with respect to the longitudinal direction of the columnar light guide 40 is the same. Moreover, the step 45 closer to the left end has a wider width 45w in the longitudinal direction of the columnar light guide 40 at that step 45, and the second inclined surface 47 in the step 45 closer to the left end has a wider width 47w2 in the longitudinal direction of the columnar light guide 40 at that second inclined surface 47. Moreover, adjacent steps 45 are connected to each other.

[0035] In this embodiment, the step 45a closest to the right end of the columnar light guide 40 is located to the right of an end 48e1 on the right side of the connection 48 between the columnar light guide 40 and the plate-shaped light guide 50. The step 45b closest to the left end of the columnar light guide 40 is located to the left of an end 48e2 on the left side of the connection 48 between the columnar light guide 40 and the plate-shaped light guide 50.

[0036] As shown in FIG. 3, in the plate-shaped light guide 50 of this embodiment, the side surfaces 50s3 on both the left and right sides of the plate-shaped light guide 50 are inclined downward toward the left side, which is the side opposite the first light source 20 side. In addition, the main surface 52s2 of the second plate-shaped portion 52 of the plate-shaped light guide 50 of this embodiment is formed with a plurality of reflecting portions 55 that internally reflect light propagating through the second plate-shaped portion 52 from the connecting portion 53 side toward the side opposite the connecting portion 53 and emit the light from the main surface 52s1. In FIG. 3, a reference symbol is attached to one reflecting portion 55, and the reference symbols of the other reflecting portions 55 are omitted. The plurality of reflecting portions 55 are arranged to form a plurality of rows aligned in a direction substantially parallel to the side surface 50s3.

[0037] 6 is a cross-sectional view of the second plate-shaped portion 52, and is a cross-sectional view of the second plate-shaped portion 52 crossing the reflecting portions 55 along the row of the reflecting portions 55. As shown in FIG. 6, in this embodiment, the reflecting portions 55 are generally hemispherical depressions, and adjacent reflecting portions 55 are spaced apart from each other. The interval between adjacent reflecting portions 55 is narrower than the width 55w of the reflecting portions 55 in the arrangement direction of the reflecting portions 55. Note that adjacent reflecting portions 55 may be connected to each other, and the interval between adjacent reflecting portions 55 may be equal to or greater than the above-mentioned width 55w.

[0038] As shown in Figs. 1 and 2, the second light source 60 of this embodiment is disposed in front of the second plate-shaped portion 52 and includes a plurality of light-emitting elements 61 that emit red light L2 toward the second plate-shaped portion 52 when the vehicle brake is operated. In this embodiment, the light-emitting elements 61 are LEDs, and the second light source 60 is an LED array in which a plurality of LEDs are arranged in the left-right direction. Note that the second light source 60 is not limited to an LED array. Also, in Fig. 1, a reference symbol is attached to one light-emitting element 61, and the reference symbols of the other light-emitting elements 61 are omitted.

[0039] The second light guide 70 of this embodiment is a member that has translucency and is disposed between the second light source 60 and the second plate-shaped portion 52. In this embodiment, the second light guide 70 has a light incident surface 71 that faces the plurality of light emitting elements 61 at a predetermined interval on the second light source 60 side, and light L2 emitted from the light emitting surface 61s of each light emitting element 61 enters through the light incident surface 71. The second light guide 70 also has a light exit surface 72 that faces the main surface 52s2 of the second plate-shaped portion 52 at a predetermined interval on the second plate-shaped portion 52 side, and emits the light L2 incident from the light incident surface 71 toward the second plate-shaped portion 52. In this embodiment, the light exit surface 72 is inclined backward from above to below along the main surface 52s2.

[0040] Examples of materials that can be used to form the second light guide 70 include transparent resin and glass, and the second light guide 70 of this embodiment is made of a colorless, transparent resin.

[0041] Next, the operation of the vehicle lamp 1 of this embodiment will be described.

[0042] First, the case where the light acts as a tail lamp will be described. When the headlights of the vehicle are turned on, the light emitting element 21 of the first light source 20 emits red light, and the light enters the columnar light guide 40 from the right end surface 41 of the columnar light guide 40 of the first light guide 30. The light that enters the columnar light guide 40 from the right end surface 41 propagates through the columnar light guide 40 toward the left end side, and is internally reflected by the second inclined surface 47 of the step 45 toward the plate-like light guide 50. As described above, the inclination α of the second inclined surface 47 of the step 45 located on the right end side with respect to the longitudinal direction of the columnar light guide 40 is larger than the inclination α of the second inclined surface 47 of the step 45 located on the left end side with respect to the longitudinal direction of the columnar light guide 40. Therefore, in the step 45 located on the right end side, the angle of incidence of the light L1 propagating through the columnar light guide 40 to the second inclined surface 47 may be smaller than that of the step 45 located on the left end side.

[0043] 4, in this embodiment, in the step 45 located on the right end side, light L1 incident on the second inclined surface 47 exits from the second inclined surface 47. This light L1 enters from the first inclined surface 46 of the adjacent step 45, is internally reflected by the second inclined surface 47 of the adjacent step 45, and is guided to the columnar light guide 40. In other words, the inclination α of the second inclined surface 47 is adjusted so that the light L1 is internally reflected in this manner.

[0044] 5, in the step 45 located on the left end side, the light L1 incident on the second inclined surface 47 is internally reflected by the second inclined surface 47 without being emitted from the second inclined surface 47, and is guided to the columnar light guide 40. In other words, the inclination α of the second inclined surface 47 is adjusted so that the light L1 is internally reflected in this manner.

[0045] The light L1 guided to the columnar light guide 40 is guided from the first plate-shaped portion 51 to the second plate-shaped portion 52 via the connection portion 53, and propagates through the second plate-shaped portion 52 from the connection portion 53 side toward the opposite side to the connection portion 53. The light L1 propagating through the second plate-shaped portion 52, which is incident on the reflecting portion 55, is internally reflected by the reflecting portion 55 toward the main surface 52s1, and is emitted from the main surface 52s1. That is, the light L1 is emitted from the main surface 52s1, which is a part of the main surface 50s1 of the columnar light guide 40. The light L1 emitted from the main surface 52s1 is irradiated toward the rear of the vehicle through the outer cover 12. In this way, the vehicle lamp 1 of this embodiment functions as a tail lamp when the headlights of the vehicle are turned on.

[0046] Next, a case where the light emitting element 61 functions as a stop lamp will be described. As shown in FIG. 2, when the brake of the vehicle is operated, the light emitting element 61 of the second light source 60 emits red light L2, and the light L2 enters the second light guide 70 from the light incident surface 71 of the second light guide 70. The light L2 that enters the second light guide 70 from the light incident surface 71 propagates through the second light guide 70 and is emitted from the light exit surface 72 toward the second plate-shaped portion 52. The light L2 that exits from the light exit surface 72 passes through the second plate-shaped portion 52 and is irradiated toward the rear of the vehicle through the outer cover 12. The luminance of the light L2 irradiated toward the rear of the vehicle in this manner is higher than the luminance of the light L1 that is emitted from the first light source 20 and irradiated toward the rear of the vehicle. That is, the luminance of the light L1 emitted from the first light source 20 and the light L2 emitted from the second light source 60 is adjusted so as to become like this. In this way, the vehicular lamp 1 of the present embodiment functions as a stop lamp when the brakes of the vehicle are operated.

[0047] As described above, the vehicle lamp 1 of the present embodiment includes the first light source 20 and the first light guide 30. The first light guide 30 includes the columnar light guide 40 and the plate-shaped light guide 50. The columnar light guide 40 guides the light L1 from the first light source 20, which is incident from the right end face 41, which is an end face on one end side and serves as an incident portion, toward the left end side, which is the other end side. The plate-shaped light guide 50 is connected to the outer circumferential surface of the columnar light guide 40 such that the in-plane direction of one main surface 50s1 is along the longitudinal direction of the columnar light guide 40. The columnar light guide 40 includes a plurality of steps 45 arranged along the longitudinal direction of the columnar light guide 40 on the side of the outer circumferential surface opposite to the side to which the plate-shaped light guide 50 is connected. The step 45 includes a first inclined surface 46 and a second inclined surface 47 located on the left end side of the first inclined surface 46. The first inclined surface 46 is a surface that inclines from the right end side to the left end side toward the opposite side to the plate-shaped light guide 50 side, and the second inclined surface 47 is a surface that inclines from the right end side to the plate-shaped light guide 50 side from the right end side to the left end side and internally reflects the light L1 from the first light source 20 toward the plate-shaped light guide 50. The plate-shaped light guide 50 emits the light guided from the columnar light guide from one main surface 50s1. The inclination α of the second inclined surface 47 in the step 45 located on the right end side with respect to the longitudinal direction of the columnar light guide 40 is larger than the inclination α of the second inclined surface 47 in the step 45 located on the left end side with respect to the longitudinal direction of the columnar light guide 40. Therefore, in the vehicle lamp 1 of this embodiment, the angle of incidence of the light L1 propagating through the columnar light guide 40 to the second inclined surface 47 may be smaller in the step 45 located on the right end side than in the step 45 located on the left end side. Therefore, as shown in FIG. 4, in the step 45 located on the right end side, the light L1 can be emitted from the second inclined surface 47, and the light L1 can be incident on the first inclined surface 46 of the adjacent step 45 and internally reflected on the second inclined surface 47 of the adjacent step 45. In this case, since the light is refracted at the second inclined surface 47 and the first inclined surface 46 of the adjacent step, the propagation direction of the light L1 when it is incident on the second inclined surface 47 of the adjacent step 45 can be made to approach the longitudinal direction of the columnar light guide 40. Therefore, the light L1 internally reflected on the second inclined surface 47 of the adjacent step 45 can be made to propagate in a direction perpendicular to the longitudinal direction of the columnar light guide 40 or in a direction toward the right end side based on the direction perpendicular to the longitudinal direction of the columnar light guide 40. The right end side of the columnar light guide 40 is the side close to the first light source 20.Therefore, according to the vehicle lamp 1 of the present embodiment, the inclination α of the second inclined surface 47 in each step 45 is the same, and the light L1 can be easily guided to the portion of the plate-shaped light guide 50 on the first light source 20 side, compared to the case where the light L1 is not emitted from the second inclined surface 47 but is internally reflected by the second inclined surface 47. Also, as shown in FIG. 5, in the step 45 located on the left end side, the light L1 is not emitted from the second inclined surface 47 but is internally reflected by the second inclined surface 47, and can be propagated in a direction toward the left end side based on a direction perpendicular to the longitudinal direction of the columnar light guide 40. The left end side of the columnar light guide 40 is opposite to the first light source 20 side. Therefore, the light L1 can be easily directed to the portion of the plate-shaped light guide 50 on the opposite side to the first light source 20 side. Therefore, according to the vehicle lamp 1 of this embodiment, the unevenness in light emission of the plate-shaped light guide 50 in the longitudinal direction of the columnar light guide 40 can be suppressed compared to the above case.

[0048] In the vehicle lamp 1 of this embodiment, the second inclined surface 47 of the step 45 closer to the right end has a larger inclination α with respect to the longitudinal direction of the columnar light guide 40. Therefore, the vehicle lamp 1 of this embodiment can further suppress uneven light emission of the plate-shaped light guide 50. Note that it is only necessary that the inclination α of the second inclined surface 47 of the step 45 located on the right end side, which is one end side, is larger than the inclination α of the second inclined surface 47 of the step 45 located on the left end side, which is the other end side. For example, the inclination α of the second inclined surface 47 of the step 45 located in the center in the longitudinal direction of the columnar light guide 40 among the multiple steps 45 may be the same.

[0049] In the vehicle lamp 1 of this embodiment, the inclination β of the first inclined surface 46 of each step 45 with respect to the longitudinal direction of the columnar light guide 40 is the same. Therefore, according to the vehicle lamp 1 of this embodiment, the design of the steps 45 can be made easier. Note that the inclination β of the first inclined surface 46 of at least one step 45 may be different from the inclination β of the first inclined surface 46 of the other steps 45. For example, the inclination β of the first inclined surface 46 of the step 45 closer to the left end may be larger, and such a configuration can prevent the step 45 on the left end side from becoming too large.

[0050] In the vehicle lamp 1 of this embodiment, the width 47w1 of the second inclined surface 47 of the step 45 located on the left end side in the direction perpendicular to the longitudinal direction of the columnar light guide 40 and toward the plate-shaped light guide 50 side is wider than the above-mentioned width 47w1 of the second inclined surface 47 of the step 45 located on the right end side. The amount of light L1 propagating through the columnar light guide 40 tends to decrease as it moves away from the right end, that is, closer to the left end. Therefore, the amount of light L1 internally reflected by the second inclined surface 47 of the step 45 located on the left end side tends to be smaller than the amount of light L1 internally reflected by the second inclined surface 47 of the step 45 located on the right end side. Therefore, with the vehicle lamp 1 of this embodiment, the difference between the amount of light directed from the step 45 located on the left end side to the portion of the plate light guide 50 opposite the light source side and the amount of light directed from the step 45 located on the right end side to the portion of the plate light guide on the light source side can be made smaller than when the width 47w1 of the second inclined surfaces 47 of each step 45 is the same. Therefore, with the vehicle lamp 1 of this embodiment, the unevenness of the light emission of the plate light guide 50 can be suppressed compared to the above case.

[0051] In the vehicle lamp 1 of this embodiment, the second inclined surface 47 of the step 45 closer to the left end has a wider width 47w1 in a direction perpendicular to the longitudinal direction of the columnar light guide 40 and toward the plate-shaped light guide 50. Therefore, the vehicle lamp 1 of this embodiment can further suppress uneven light emission of the plate-shaped light guide 50. Note that the width 47w1 of the second inclined surface 47 of the step 45 located on the left end side may be narrower than the width 47w1 of the second inclined surface 47 of the step 45 located on the right end side, or the width 47w1 of the second inclined surface 47 of each step 45 may be the same.

[0052] In the vehicle lamp 1 of this embodiment, the step 45a closest to the right end is located to the right of the end 48e1 on the right end side of the connection portion 48 between the columnar light guide 40 and the plate-shaped light guide 50. Therefore, according to the vehicle lamp 1 of this embodiment, it is possible to suppress the light L1 from being difficult to be guided to the portion of the plate-shaped light guide 50 on the first light source 20 side, compared to a case in which the step 45a closest to the right end is located to the left of the end 48e1 on the right end side of the connection portion 48. Note that the step 45a closest to the right end may be located to the left of the end 48e1 on the right end side of the connection portion 48.

[0053] In the vehicle lamp 1 of this embodiment, the step 45b closest to the left end is located to the left of the end 48e2 on the left end side of the connection portion 48 between the columnar light guide 40 and the plate-shaped light guide 50. Therefore, according to the vehicle lamp 1 of this embodiment, it is possible to suppress the light L1 from being difficult to be guided to a portion of the plate-shaped light guide 50 on the opposite side to the first light source 20 side, compared to a case in which the step 45b closest to the left end is located to the right of the end 48e2 on the left end side of the connection portion 48. Note that the step 45b closest to the left end may be located to the right of the end 48e2 on the left end side of the connection portion 48.

[0054] Although the present invention has been described above using the above-mentioned embodiments as examples, the present invention is not limited to these.

[0055] For example, in the above embodiment, the columnar light guide 40 is cylindrical in shape, with the longitudinal direction inclined toward the rear side from approximately right to left. However, the columnar light guide 40 only needs to guide the light from the first light source 20 incident from the incident portion at one end side toward the other end side. For example, the longitudinal direction of the columnar light guide 40 may be the up-down direction, and the shape of the columnar light guide 40 may be a quadrangular column. Also, in the above embodiment, the incident portion into which the light from the first light source 20 is incident is the right end surface 41. However, the incident portion is not limited to the end surface. For example, the columnar light guide 40 may further have a columnar introduction portion connected to one end side, and the light from the first light source 20 may be incident from the end surface of the introduction portion. In this case, the end surface of the introduction portion becomes the incident portion.

[0056] In the above embodiment, the first light guide 30 including the columnar light guide 40 in which adjacent steps 45 are connected has been described as an example. However, adjacent steps 45 may be spaced apart, and such a modified example will be described with reference to Figs. 7 and 8. Fig. 7 is a diagram showing the first light guide 30 in the modified example similar to Fig. 4, and Fig. 8 is a diagram showing the first light guide 30 in the modified example similar to Fig. 5. The vehicle lamp 1 of this modified example differs from the vehicle lamp 1 of the above embodiment in that adjacent steps 45 are spaced apart. In this modified example, the interval 45L between adjacent steps 45 at the left end side, which is the other end side, is narrower than the interval 45L between adjacent steps 45 at the right end side, which is one end side. Therefore, the number of steps 45 per unit length of the columnar light guide 40 at the left end side is greater than the number of steps 45 per unit length of the columnar light guide 40 at the right end side. Therefore, according to the vehicle lamp 1 of this modification, the difference between the amount of light directed from the step 45 located on the left end side toward the portion of the plate-shaped light guide 50 opposite to the light source side and the amount of light directed from the step 45 located on the right end side toward the portion of the plate-shaped light guide on the light source side can be made smaller than when the intervals 45L of the steps 45 are the same. Therefore, according to the vehicle lamp 1 of this modification, the unevenness of the light emission of the plate-shaped light guide 50 can be suppressed compared to the above case. In addition, in this modification, the intervals 45L of the adjacent steps 45 are narrower toward the left end. Therefore, according to the vehicle lamp 1 of this modification, the unevenness of the light emission of the plate-shaped light guide 50 can be further suppressed. Note that the intervals 45L of the adjacent steps 45 may be constant in the longitudinal direction of the columnar light guide 40. Also, some of the adjacent steps 45 may be separated from each other, and other adjacent steps 45 may be connected to each other.

[0057] In the above embodiment, the step 45 closer to the left end has a wider width 45w in the longitudinal direction of the columnar light guide 40 at the step 45, and the second inclined surface 47 in the step 45 closer to the left end has a wider width 47w2 in the longitudinal direction of the columnar light guide 40 at the second inclined surface 47. However, the widths 45w and 47w2 are not limited. For example, the widths 45w in each step 45 may be the same. The widths 47w2 in each step 45 may be the same.

[0058] In the above embodiment, the plate-shaped light guide 50 includes the first plate-shaped portion 51, the second plate-shaped portion 52, and the connection portion 53, and is bent downward toward the rear. However, the shape of the plate-shaped light guide 50 is not limited. For example, the plate-shaped light guide 50 may be composed of only the second plate-shaped portion 52, and the upper end of the second plate-shaped portion 52 may be connected to the columnar light guide 40.

[0059] In the above embodiment, the plate-shaped light guide 50 having a plurality of reflecting portions 55, which are hemispherical depressions, has been described as an example. However, the plate-shaped light guide 50 may have another configuration as long as the light L1 guided from the columnar light guide 40 is emitted from one of the main surfaces 50s1. For example, the reflecting portion 55 may be a conical depression. The plate-shaped light guide 50 may not have the reflecting portion 55. For example, the plate-shaped light guide 50 may include a light-transmitting plate-shaped base material made of resin or glass, and an optical element portion dispersed in the base material for reflecting or refracting light. Examples of the optical element portion that reflects light include inorganic fine particles such as alumina. Examples of the optical element portion that reflects or refracts light include fine particles and voids made of resin or glass having a refractive index different from that of the base material. With this configuration, the light L1 propagating through the base material of the plate-shaped light guide 50 can be reflected or refracted by the optical element portion and emitted from one of the main surfaces of the base material.

[0060] In the above embodiment, the first light source 20 that emits red light L1 has been described as an example. However, the color of the light L1 emitted by the first light source 20 is not limited. For example, the color of the light L1 may be white. In this case, for example, the first light guide 30 is made of red transparent resin or glass.

[0061] In the above embodiment, the vehicle lamp 1 is a combination lamp for a four-wheeled vehicle. However, the vehicle lamp 1 is not limited to this. For example, the vehicle lamp 1 may be a tail lamp without the second light source 60 and the second light guide 70. The vehicle lamp 1 may be a turn lamp, a stop lamp, or the like, or may be one of these lamps for a two-wheeled vehicle. [Industrial Applicability]

[0062] According to the present invention, a vehicle lamp capable of suppressing uneven light emission from a plate-shaped light guide is provided, and can be used in fields such as vehicle lamps for automobiles and the like. [Explanation of symbols]

[0063] 1. Vehicle lighting fixture 20...1st light source (light source) 40...Columnar light guide 45 steps 46...First slope 47 Second Slope 50....Plate-shaped light guide

Claims

1. A light source; a columnar light guide that guides light from the light source incident on an incident portion at one end side toward the other end side; a plate-shaped light guide connected to an outer peripheral surface of the columnar light guide such that an in-plane direction of one of the main surfaces is aligned with a longitudinal direction of the columnar light guide; Equipped with the columnar light guide includes a plurality of steps arranged along a longitudinal direction of the columnar light guide on an opposite side of the outer circumferential surface to a side to which the plate-shaped light guide is connected, the step has a first inclined surface inclined from the one end side toward the other end side toward a side opposite to the plate-shaped light guide, and a second inclined surface located on the other end side of the first inclined surface inclined toward the plate-shaped light guide from the one end side toward the other end side to internally reflect light from the light source toward the plate-shaped light guide, the plate-shaped light guide emits the light guided from the columnar light guide from the one main surface, The inclination of the second inclined surface of the step located on the one end side with respect to the longitudinal direction of the columnar light guiding body is greater than the inclination of the second inclined surface of the step located on the other end side with respect to the longitudinal direction of the columnar light guiding body. A vehicle lamp characterized by the above.

2. The second inclined surface of the step closer to the one end has a greater inclination with respect to the longitudinal direction of the columnar light guide.

2. The vehicle lamp according to claim 1.

3. The inclination of the first inclined surface of each of the steps with respect to the longitudinal direction of the columnar light guide is the same.

2. The vehicle lamp according to claim 1.

4. The width of the second inclined surface of the step located on the other end side in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-shaped light guide is wider than the width of the second inclined surface of the step located on the one end side in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-shaped light guide.

2. The vehicle lamp according to claim 1.

5. The second inclined surface of the step closer to the other end has a larger width in a direction perpendicular to the longitudinal direction of the columnar light guide and toward the plate-like light guide.

5. The vehicle lamp according to claim 4.

6. The step closest to the one end is located closer to the one end than the end of the connection portion between the columnar light guide and the plate-shaped light guide.

2. The vehicle lamp according to claim 1.

7. The step closest to the other end is located closer to the other end than the end of the connection portion between the columnar light guide and the plate-shaped light guide.

7. A vehicle lamp according to claim 1, wherein the first and second electrodes are arranged in a first direction.

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