Vehicle lamp fitting

Abstract

To provide a vehicle lamp fitting which can expand a light emitting range in a light guide plate.SOLUTION: A vehicle lamp fitting 1 includes lamp units 10R and 10L each including a light source 20 and a light guide body unit 40. The light guide body unit 40 includes: a pair of columnar light guide bodies 41, 42 which guide light from the light source 20 and are arranged parallel to each other so as to be optically connected in a radial direction; and a light guide plate 60 which is connected to an outer peripheral surface of the columnar light guide body 41 and emits light propagated in the columnar light guide body 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART There are vehicle lamps that include a light source and a light guide unit that guides light from the light source, and Patent Document 1 below discloses such a vehicle lamp.

[0003] In the vehicle lamp disclosed in Patent Document 1, the light guide unit is composed of one columnar light guide and a light guide plate connected to the outer peripheral surface of the columnar light guide. This columnar light guide guides light from a light source from one end to the other end in the longitudinal direction. Light propagating through the columnar light guide is guided to the light guide plate, which then emits the light guided from the columnar light guide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 157585 Summary of the Invention [Problem to be solved by the invention]

[0005] In such a light guide unit, the amount of light propagating through the columnar light guide tends to decrease toward the other end, and a longer columnar light guide may make it difficult to propagate light farther. For this reason, there is a demand for a light guide plate that can propagate light farther and expand the light emission range.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle lamp that can widen the range over which light is emitted from a light guide plate. [Means for solving the problem]

[0007] In order to achieve the above object, the vehicle lamp of the present invention is characterized by comprising a lamp unit including a light source, a pair of columnar light guides arranged in parallel to each other so as to guide light from the light source and optically connect them in the radial direction, and a light guide unit including a light guide plate connected to the outer surface of one of the columnar light guides and emitting light propagating through that one columnar light guide.

[0008] In the light guide unit of this vehicle lamp, a light guide plate is connected to the outer peripheral surface of one of a pair of columnar light guides arranged side by side so as to be optically connected in the radial direction. Therefore, light propagating through the other columnar light guide, to which the light guide plate is not connected, propagates to the other columnar light guide connected to the light guide plate, and then to the light guide plate. Therefore, this vehicle lamp makes it easier for light from the light source to remain in the pair of columnar light guides, compared to a light guide unit consisting of a single columnar light guide and a light guide plate connected to the outer peripheral surface of the columnar light guide. Therefore, this vehicle lamp makes it possible for light from the light source to propagate from one columnar light guide to the light guide plate even at a position farther from the light source, compared to the above case. Therefore, this vehicle lamp makes it possible for light to propagate farther in the columnar light guide, and to widen the light emission range of the light guide plate.

[0009] The light guide unit may further include a connecting light guide plate connected to each of the outer peripheral surfaces of the pair of columnar light guides.

[0010] In a cross section perpendicular to the longitudinal direction of the one of the columnar light guides, the thickness of the light guide plate at the connection portion with the one of the columnar light guides may be equal to or less than the thickness of the connecting light guide plate at the connection portion with the one of the columnar light guides.

[0011] With this configuration, light can be more difficult to propagate from one columnar light guide to the light guide plate than when the thickness of the light guide plate at the connection portion with one columnar light guide is smaller than the thickness of the connecting light guide plate at the connection portion with one columnar light guide in the cross section, and therefore, light can be more easily propagated from one columnar light guide to the light guide plate even at a position farther away from the light source than in the above case.

[0012] The thickness of the connecting light guide plate may be smaller toward the light source.

[0013] With this configuration, it is possible to make it difficult for light to propagate from the other columnar light guide to one of the columnar light guides on the light source side, so that when light from the light source is incident on the light source side of the other columnar light guide, more light can be propagated to the side of the other columnar light guide opposite to the light source side, and light can be propagated from one of the columnar light guides to the light guide plate even at a position away from the light source.

[0014] When the light guide unit includes a connecting light guide plate, the spacing between the pair of columnar light guides may be wider toward the light source.

[0015] With this configuration, it is possible to make it difficult for light to propagate from the other columnar light guide to one of the columnar light guides on the light source side, so that when light from the light source is incident on the light source side of the other columnar light guide, a large amount of light can be propagated to the side of the other columnar light guide opposite to the light source side, and light can be propagated from one of the columnar light guides to the light guide plate even at a position away from the light source.

[0016] In this case, the outer circumferential surfaces of the pair of columnar light guides on the side opposite to the light source side may be connected to each other.

[0017] With this configuration, it is possible to make it difficult for light from the light source to remain on the side of the other columnar light guide opposite to the light source side, thereby improving energy efficiency.

[0018] The pair of columnar light guides may be optically connected by connecting outer circumferential surfaces of the pair of columnar light guides to each other.

[0019] The amount of light from the light source incident on the other columnar light guide may be greater than the amount of light from the light source incident on one columnar light guide.

[0020] With this configuration, more light can be propagated to the other columnar light guide in the direction opposite to the light source side compared to when the amount of light from the light source incident on one columnar light guide is equal to or less than the amount of light from the light source incident on the other columnar light guide, and therefore light can be propagated from one columnar light guide to the light guide plate even at a position far from the light source.

[0021] The other columnar light guide may be thicker than the one columnar light guide.

[0022] With this configuration, more light can be propagated in the direction opposite to the light source side of the other columnar light guide than when the other columnar light guide is thinner than the first columnar light guide, so that light can be propagated from the columnar light guide to the light guide plate even at a position far from the light source.

[0023] At least one of the pair of columnar light guides may be thinner on the side opposite to the light source side.

[0024] With this configuration, it is possible to make it difficult for light from the light source to remain on the side opposite to the light source side of at least one of the pair of columnar light guides, thereby improving energy efficiency.

[0025] The lighting unit may further include at least one sub-light source, and the light guide unit may further include at least one light entrance portion connected to one of the pair of columnar light guides on the side opposite to the light source side from a position where light from the light source is incident, and into which light from the sub-light source is incident, and the light entrance portion may guide the light from the sub-light source that is incident on the light entrance portion to the columnar light guide to which the light entrance portion is connected so as to propagate toward the side opposite to the light source side.

[0026] With this configuration, the amount of light propagating from one columnar light guide to the light guide plate can be increased at a position away from the light source, and the position on the light guide plate far from the light source can be prevented from becoming dark.

[0027] The vehicle lamp may include a pair of the lamp units, and an end portion of the pair of columnar light guides of the light guide unit in one of the lamp units opposite the light source side may be connected to an end portion of the pair of columnar light guides of the light guide unit in the other lamp unit opposite the light source side.

[0028] With this configuration, light propagating through the pair of columnar light guides of the light guide unit in one lamp unit can be emitted from the light guide plate of the light guide unit in the other lamp unit. Also, light propagating through the pair of columnar light guides of the light guide unit in the other lamp unit can be emitted from the light guide plate of the light guide unit in one lamp unit. This can prevent light from the light source from remaining in the columnar light guides, thereby improving energy efficiency.

[0029] In this case, the end of the light guide plate of the light guide unit in one of the lighting units opposite the light source side may be connected to the end of the light guide plate of the light guide unit in the other lighting unit opposite the light source side.

[0030] With this configuration, the range over which light is emitted can be continuously expanded. [Effects of the Invention]

[0031] As described above, according to the present invention, it is possible to provide a vehicle lamp that can widen the range over which light is emitted from the light guide plate. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a plan view showing a vehicle lamp according to an embodiment of the present invention; [Figure 2] FIG. 2 is an enlarged view of the right lamp unit. [Figure 3] FIG. 3 is a cross-sectional view of the light guide unit taken along line III-III in FIG. [Figure 4] 4 is a cross-sectional view of a connecting light guide plate taken along the longitudinal direction of a columnar light guide. FIG. [Figure 5]1 is a diagram for explaining propagation of light in a vehicle lamp; [Figure 6] 10 is a view similar to FIG. 2 showing the right lamp unit in the first modified example. FIG. [Figure 7] FIG. 7 is a cross-sectional view of the light guide unit taken along line VII-VII in FIG. 6. [Figure 8] 10 is a view similar to FIG. 2 showing the right lamp unit in a second modified example. FIG. [Figure 9] 9 is a cross-sectional view of the light guide unit taken along line IX-IX in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0033] Preferred embodiments of a vehicle lamp according to the present invention will now be described in detail 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 within the scope of the claims without departing from the spirit thereof. The present invention may also be implemented by appropriately combining the components in the embodiments exemplified below. Note that in the drawings referred to below, the dimensions of each component may be changed to facilitate understanding. Also, in the drawings, for ease of viewing, similar components may be denoted with reference numerals only in some cases, and some reference numerals may be omitted.

[0034] 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 tail lamp for a four-wheeled motor vehicle and is provided at the rear of the vehicle. The upper side in Fig. 1 is the left side of the vehicle, the lower side is the right side of the vehicle, the left side is the rear side of the vehicle, and the right side is the front side 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.

[0035] As shown in Fig. 1, the vehicle lamp 1 of this embodiment mainly comprises a housing 5 and a pair of lamp units 10R, 10L. In Fig. 1, the housing 5 is shown in horizontal cross section.

[0036] The housing 5 has a lamp housing 6 and a light-transmitting outer cover 7. The rear of the lamp housing 6 is open, and the outer cover 7 is fixed to the lamp housing 6 so as to close the opening. A pair of lamp units 10R, 10L are housed in a space R formed by the lamp housing 6 and the outer cover 7.

[0037] In this embodiment, one lamp unit 10R is disposed on the right side of the space R, and the other lamp unit 10L is disposed on the left side of the space R. These lamp units 10R, 10L have the same configuration except that their shapes are roughly symmetrical in the left-right direction. Therefore, the following description will focus on the right lamp unit 10R. Note that components of the left lamp unit 10L that are the same as or equivalent to those of the right lamp unit 10R will be given the same reference numerals and will not be described again unless otherwise specified.

[0038] The lamp unit 10R of this embodiment mainly comprises a light source 20, three sub-light sources 31, 32, and 33, and a light guide unit 40. As will be described in detail later, the left end of the light guide unit 40 in the right lamp unit 10R is connected to the right end of the light guide unit 40 in the left lamp unit 10L. In FIG. 1, the boundary between the light guide unit 40 of the right lamp unit 10R and the light guide unit 40 of the left lamp unit 10L is indicated by a dotted line.

[0039] In this embodiment, the light source 20 emits red light when the vehicle headlights are turned on. The light source 20 is an LED (Light Emitting Diode), but is not limited thereto.

[0040] In this embodiment, the sub-light sources 31, 32, and 33 each emit red light when the vehicle headlights are turned on. The sub-light sources 31 to 33 are LEDs, but are not limited to LEDs.

[0041] Fig. 2 is an enlarged view of the right-side lamp unit 10R. Fig. 3 is a cross-sectional view of the light guide unit 40 taken along line III-III in Fig. 2. As shown in Figs. 2 and 3, the light guide unit 40 includes a pair of columnar light guides 41 and 42, a connecting light guide plate 45, three light entrance portions 51, 52, and 53, and a light guide plate 60.

[0042] The pair of columnar light guides 41, 42 of this embodiment are cylindrical members having translucency. One columnar light guide 41 extends from the right side of the space R toward the center of the space R in the left-right direction, and the longitudinal direction of the columnar light guide 41 is generally parallel to the horizontal direction. One end, i.e., the right end, of the columnar light guide 41 is curved toward the rear, and an end face 41s at one end of the columnar light guide 41 faces diagonally rearward and to the right. The end face 41s is a flat surface generally perpendicular to the central axis of the columnar light guide 41. The thickness of the columnar light guide 41 is generally constant in the longitudinal direction. Note that FIG. 3 is a cross-sectional view of the light guide unit 40 taken along a plane perpendicular to the longitudinal direction of the columnar light guide 41 and crossing a groove 62 (described later).

[0043] The other columnar light guide 42 is located rearward of the columnar light guide 41 and extends along the columnar light guide 41 with a gap therebetween. Therefore, the pair of columnar light guides 41, 42 are arranged parallel to each other in the front-rear direction. One end, i.e., the right end, of the columnar light guide 42 is curved rearward, similar to the columnar light guide 41, and an end face 42s at one end of the columnar light guide 42 faces diagonally rearward and rightward. The end face 42s is a plane that is approximately perpendicular to the central axis of the columnar light guide 42. The end face 42s and the end face 41s of the columnar light guide 41 are located on the same plane, but this is not limitative. The light source 20 is arranged to face the end face 42s of the columnar light guide 42 with a predetermined gap therebetween. Light emitted from the light source 20 enters the columnar light guide 42 from the end face 42s, and the columnar light guide 42 guides the light incident from the end face 42s toward the other end. Furthermore, almost no light is emitted from the light source 20 and enters the columnar light guide 41 from the end face 41s. That is, the amount of light from the light source 20 that enters the columnar light guide 42 is greater than the amount of light from the light source 20 that enters the columnar light guide 41. Furthermore, one end side of the columnar light guides 41, 42 faces the light source 20, and the other end side of the columnar light guides 41, 42 faces the opposite side to the light source 20.

[0044] The columnar light guide 42 is thicker than the columnar light guide 41, and the thickness of the columnar light guide 42 is approximately constant in the longitudinal direction. The interval W between the pair of columnar light guides 41, 42 is approximately constant in the longitudinal direction of the columnar light guide 41. The interval W is the distance between the central axis 41c of the columnar light guide 41 and the central axis 42c of the columnar light guide 42.

[0045] The connecting light guide plate 45 is a translucent plate-like member connected to each of the outer circumferential surfaces of the pair of columnar light guides 41, 42. The connecting light guide plate 45 of this embodiment extends along the columnar light guide 41 between the pair of columnar light guides 41, 42, with the front end of the connecting light guide plate 45 connected to the rear side of the outer circumferential surface of the columnar light guide 41 and the rear end of the connecting light guide plate 45 connected to the front side of the outer circumferential surface of the columnar light guide 42. The connecting light guide plate 45 is connected to the outer circumferential surface of the columnar light guide 41 over the entire longitudinal direction of the columnar light guide 41, and is connected to the outer circumferential surface of the columnar light guide 42 over the entire longitudinal direction of the columnar light guide 42. The connecting light guide plate 45 is flat, and in a cross section perpendicular to the longitudinal direction of the columnar light guides 41, a line segment LS connecting the central axis 41c of the columnar light guide 41 and the central axis 42c of the columnar light guide 42 passes continuously through the connecting light guide plate 45. The pair of columnar light guides 41, 42 arranged in parallel with each other are optically connected in the radial direction by the connecting light guide plate 45. Therefore, light propagating through the columnar light guide 41 can propagate to the columnar light guide 42 via the connecting light guide plate 45, and light propagating through the columnar light guide 42 can propagate to the columnar light guide 41 via the connecting light guide plate 45.

[0046] FIG. 4 is a cross-sectional view of the connecting light guide plate 45 taken along the longitudinal direction of the columnar light guide 41. In FIG. 4, the right side is the light source 20 side, and the left side is the side opposite the light source 20 side. As shown in FIG. 4, in this embodiment, the thickness 45t of the connecting light guide plate 45 is smaller toward the light source 20 side and gradually decreases toward the light source 20 side. Note that the thickness 45t may decrease in stages toward the light source 20 side. Furthermore, as shown in FIG. 3, the thickness 45t of the connecting light guide plate 45 is generally constant in the direction perpendicular to the longitudinal direction of the columnar light guide 41, but it does not have to be constant.

[0047] As shown in FIG. 2 , the light entrance sections 51 to 53 of this embodiment are cylindrical members having translucency. The light entrance section 51 extends diagonally rearward and rightward from the rear side of the outer peripheral surface of the columnar light guide 42. The light entrance section 52 extends diagonally rearward and rightward from the rear side of the outer peripheral surface of the columnar light guide 42, on the light source 20 side, relative to a connection section 51c between the light entrance section 51 and the columnar light guide 42. The light entrance section 53 extends diagonally rearward and rightward from the rear side of the outer peripheral surface of the columnar light guide 42, on the light source 20 side, relative to a connection section 52c between the light entrance section 52 and the columnar light guide 41. As described above, light emitted from the light source 20 enters the columnar light guide 42 through the end face 42s. That is, the light entrance sections 51 to 53 are connected to the outer peripheral surface of the columnar light guide 42 on the side opposite to the light source 20 side from the position where light from the light source 20 enters the light source 20. The distance between the connection portion 53c of the light entrance portion 53 and the columnar light guide 41 and the connection portion 52c is generally the same as the distance between the connection portion 51c and the connection portion 52c, but may be different.

[0048] An end face 51s of the light entrance portion 51 opposite to the columnar light guide 42 side is a flat surface that is approximately perpendicular to the central axis of the light entrance portion 51. Similar to the end face 51s, end faces 52s and 53s of the light entrance portions 52 and 53 opposite to the columnar light guide 42 side are flat surfaces that are approximately perpendicular to the central axes of the light entrance portions 52 and 53. Note that the end faces 51s to 53s may be flat surfaces that are not perpendicular to the central axes of the light entrance portions 51 to 53, or may be curved surfaces.

[0049] The sub-light source 31 is arranged to face the end face 51s at a predetermined distance. Light emitted from the sub-light source 31 enters the light entrance portion 51 from the end face 51s and is guided to the columnar light guide 42 so that the light propagates through the columnar light guide 42 toward the side opposite to the light source 20. The sub-light source 32 is arranged to face the end face 52s at a predetermined distance. Light emitted from the sub-light source 32 enters the light entrance portion 52 from the end face 52s and is guided to the columnar light guide 42 so that the light propagates through the columnar light guide 42 toward the side opposite to the light source 20. The sub-light source 33 is arranged to face the end face 53s at a predetermined distance. Light emitted from the sub-light source 33 enters the light entrance portion 53 from the end surface 53s, and is guided to the columnar light guide 42 so that the light propagates through the columnar light guide 42 toward the side opposite to the light source 20. That is, the light entrance portion 51 corresponds to the sub-light source 31, the light entrance portion 52 corresponds to the sub-light source 32, and the light entrance portion 53 corresponds to the sub-light source 33. The light entrance portions 51 to 53 guide the light from the sub-light sources 31 to 33 that enters the light entrance portions 51 to 53 to the columnar light guide 42 so that the light propagates through the columnar light guide 42 toward the side opposite to the light source 20.

[0050] As shown in FIGS. 2 and 3 , the light guide plate 60 is a translucent plate-like member. An end of the light guide plate 60 is connected to the outer peripheral surface of the columnar light guide 41 along the longitudinal direction of the columnar light guide 41, thereby guiding light propagating through the columnar light guide 41. In this embodiment, the light guide plate 60 is connected to the rear side of the outer peripheral surface of the columnar light guide 41 in a continuous section extending from the vicinity of one end of the columnar light guide 41 that curves rearward to the other end opposite the light source 20. The light guide plate 60 is a flat plate that extends rearward from the columnar light guide 41 and is generally parallel to the horizontal direction. Therefore, one main surface 60s1 of the light guide plate 60 faces upward, and the other main surface 60s2 faces downward. The thickness 60t of the light guide plate 60 is generally constant at any position. In a cross section perpendicular to the longitudinal direction of the columnar light guide 41, the thickness 60t of the light guide plate 60 at the connection portion 60c with the columnar light guide 41 is smaller than the thickness 45t of the connecting light guide plate 45 at the connection portion 45c with the columnar light guide 41. The thickness 60t of the light guide plate 60 may vary in a direction parallel to the longitudinal direction of the columnar light guide 41 or in a direction perpendicular to the longitudinal direction of the columnar light guide 41. As will be described in detail later, in such a light guide plate 60, light from the light source 20 is guided from the columnar light guide 41, and the light guide plate 60 guides the light guided from the columnar light guide 41 from the columnar light guide 41 side to an end face 61 opposite to the columnar light guide 41 side.

[0051] The light guide plate 60 of this embodiment also has a plurality of grooves 62. The grooves 62 are depressions provided in the main surface 60s1 of the light guide plate 60 and are aligned along the columnar light guide 41 at predetermined intervals. The interval between the columnar light guide 41 and the groove 62 is not limited, but is preferably smaller than the diameter of the columnar light guide 41. The interval between the columnar light guide 41 and the groove 62 is the distance from the ridge between the main surface 60s1 and the outer circumferential surface of the columnar light guide 41 to the groove 62. The interval between adjacent grooves 62 is generally constant. The groove 62 of this embodiment has an outer shape of a triangle with one side generally along the columnar light guide 41. Therefore, the groove 62 includes a surface 62a along the columnar light guide 41, an inclined surface 62b located on the light source 20 side, and an inclined surface 62c located on the opposite side from the light source 20 side. The inclined surface 62b is inclined away from the columnar light guide 41 in a direction away from the light source 20, and the inclined surface 62c is inclined away from the columnar light guide 41 in a direction approaching the light source 20. The depth of the groove 62 is approximately the same as the thickness 60t of the light guide plate 60, and a lid portion 65 including a bottom surface 62d of the groove 62 is provided on the main surface 60s2. The outer shape of the groove 62 gradually becomes smaller toward the bottom surface 62d.

[0052] As described above, in this embodiment, the left end of the light guide unit 40 in the right lamp unit 10R is connected to the right end of the light guide unit 40 in the left lamp unit 10L. Specifically, the left end, which is the end of the columnar light guide 41 of the lamp unit 10R opposite to the light source 20 side, is connected to the right end, which is the end of the columnar light guide 41 of the lamp unit 10L opposite to the light source 20 side. The outer peripheral surfaces of the columnar light guide 41 of the lamp unit 10R and the columnar light guide 41 of the lamp unit 10L are connected without any step. Furthermore, similar to the columnar light guide 41, the left end of the columnar light guide 42 of the lamp unit 10R is connected to the right end of the columnar light guide 42 of the lamp unit 10L. The outer peripheral surfaces of the columnar light guides 42 of the lamp unit 10R and the columnar light guides 42 of the lamp unit 10L are connected without any step. Similarly to the columnar light guides 41, the left end of the connecting light guide plate 45 of the lamp unit 10R is connected to the right end of the connecting light guide plate 45 of the lamp unit 10L. The upper and lower main surfaces of the connecting light guide plate of the lamp unit 10R are connected to the upper and lower main surfaces of the connecting light guide plate 45 of the lamp unit 10L without any step. Similarly to the connecting light guide plate 45, the left end of the light guide plate 60 of the lamp unit 10R is connected to the right end of the light guide plate 60 of the lamp unit 10L. The upper and lower main surfaces 60s1, 60s2 of the light guide plate 60 of the lamp unit 10R are connected to the upper and lower main surfaces 60s1, 60s2 of the light guide plate 60 of the lamp unit 10L without any step. Furthermore, the end face 61 of the light guide plate 60 of the lamp unit 10R and the end face 61 of the light guide plate 60 of the lamp unit 10L are connected without any step.

[0053] Examples of materials that can be used to form the light guide unit 40 include transparent resin and glass, and the light guide unit 40 of this embodiment is made of a colorless, transparent resin. The pair of columnar light guides 41, 42, the connecting light guide plate 45, the light entrance portions 51 to 53, and the light guide plate 60 are integral with each other, with no seams formed between these components. The light guide unit 40 of the lamp unit 10R and the light guide unit 40 of the lamp unit 10L are also integral with each other, with no seams formed between these light guide units 40.

[0054] Next, the operation of the vehicle lamp 1 of this embodiment will be described.

[0055] Fig. 5 is a diagram illustrating light propagation in the vehicle lamp 1, and is a horizontal cross-sectional view of the vehicle lamp 1. Note that the housing 5 is not shown in Fig. 5. The boundary between the pair of columnar light guides 41, 42 and the connecting light guide plate 45, and the boundary between the columnar light guide 41 and the light guide plate 60 are indicated by dotted lines. The propagation of light from the light source 20 and sub-light sources 31 to 33 of the right-side lamp unit 10R is schematically indicated by dashed dotted lines, and the propagation of light from the light source 20 and sub-light sources 31 to 33 of the left-side lamp unit 10L is schematically indicated by dashed two-dotted lines.

[0056] When the vehicle headlights are turned on, the light source 20 and the sub-light sources 31 to 33 each emit red light. As shown in Fig. 5, the light emitted from the light source 20 enters the columnar light guide 42 from an end surface 42s of the columnar light guide 42 in the light guide unit 40, and the light that has entered the columnar light guide 42 propagates in a direction opposite to the light source 20 side. The sub-light sources 31 to 33 enter the light entrance portions 51 to 53 from end surfaces 51s to 53s of the light entrance portions 51 to 53 in the light guide unit 40, are guided from the light entrance portions 51 to 53 to the columnar light guide 42, and propagate through the columnar light guide 42 in a direction opposite to the light source 20 side. The light propagating through the columnar light guide 42 enters the columnar light guide 41 via the connecting light guide plate 45, and the light that enters the columnar light guide 41 propagates through the columnar light guide 41 toward the opposite side to the light source 20. Although not illustrated, some light propagates from the columnar light guide 41 to the columnar light guide 42 via the connecting light guide plate 45. Of the light that propagates through the pair of columnar light guides 41, 42 toward the opposite side to the light source 20, the light that propagates through the columnar light guide 41 enters the light guide plate 60. The light that enters the light guide plate 60 is internally reflected by the slopes 62b of the grooves 62 toward the end face 61 and is emitted rearward from the end face 61.

[0057] In this embodiment, the left end of the light guide unit 40 in the right lamp unit 10R is connected to the right end of the light guide unit 40 in the left lamp unit 10L. Therefore, part of the light propagating through the pair of columnar light guides 41, 42 in the lamp unit 10R toward the opposite side from the light source 20 propagates through the pair of columnar light guides 41, 42 in the lamp unit 10L and then propagates through the pair of columnar light guides 41, 42 toward the opposite side from the lamp unit 10R. Of the light propagating in this way, the light propagating through the columnar light guide 41 enters the light guide plate 60, is internally reflected by the slopes 62c of the grooves 62 toward the end face 61, and is emitted rearward from the end face 61. Furthermore, a part of the light propagating through the pair of columnar light guides 41, 42 in the lamp unit 10L toward the opposite side to the light source 20 propagates to the pair of columnar light guides 41, 42 in the lamp unit 10R and then propagates through the pair of columnar light guides 41, 42 toward the opposite side to the lamp unit 10L. Of the light propagating in this way, the light propagating through the columnar light guide 41 enters the light guide plate 60, is internally reflected by the inclined surfaces 62c of the grooves 62 toward the end face 61, and is emitted rearward from the end face 61.

[0058] In this way, light is emitted rearward from the end surface 61 of the light guide plate 60, and the light is irradiated toward the rear of the vehicle through the outer cover 7. In this way, the vehicle lamp 1 of this embodiment functions as a tail lamp when the headlights of the vehicle are turned on.

[0059] As described above, the vehicle lamp 1 of this embodiment includes the lamp units 10R, 10L, each including a light source 20 and a light guide unit 40. The light guide unit 40 includes a pair of columnar light guides 41, 42 arranged in parallel to each other so as to be optically connected in the radial direction, and a light guide plate 60 connected to the outer peripheral surface of one of the columnar light guides 41 to emit light propagating through the columnar light guide 41. The pair of columnar light guides 41, 42 guide light from the light source 20. Light propagating through the columnar light guide 42 to which the light guide plate 60 is not connected propagates to the columnar light guide 41 to which the light guide plate 60 is connected, and then to the light guide plate 60. Therefore, according to the vehicle lamp 1 of this embodiment, light from the light source 20 can be more likely to remain in the pair of columnar light guides 41, 42 of the light guide unit 40, compared to when the light guide unit is composed of one columnar light guide and a light guide plate connected to the outer peripheral surface of the columnar light guide. Therefore, light from the light source 20 can be propagated from the columnar light guide 41 to the light guide plate 60 even at a position distant from the light source 20. Therefore, according to the vehicle lamp 1 of this embodiment, light can be propagated farther in the columnar light guides 41, 42, compared to the above case, and the range over which light is emitted from the light guide plate 60 can be widened.

[0060] In the vehicle lamp 1 of this embodiment, the amount of light from the light source 20 incident on the columnar light guide 42 is greater than the amount of light from the light source 20 incident on the columnar light guide 41. Therefore, according to the vehicle lamp 1 of this embodiment, more light can be propagated to the side of the columnar light guide 42 opposite to the light source 20 side, compared to when the amount of light from the light source 20 incident on the columnar light guide 42 is equal to or less than the amount of light from the light source 20 incident on the columnar light guide 41. Therefore, even at a position distant from the light source 20, the light from the light source 20 can be propagated from the columnar light guide 41 to the light guide plate 60. Note that the amount of light from the light source 20 incident on the columnar light guide 42 may be equal to or less than the amount of light from the light source 20 incident on the columnar light guide 41. Alternatively, the light emitted from the light source 20 may be incident only on the columnar light guide 42, and not on the columnar light guide 41. That is, the light emitted from the light source 20 may be incident only on the end surface 42s of the columnar light guide 42, but not on the end surface 41s of the columnar light guide 41. Alternatively, the light emitted from the light source 20 may be incident only on the columnar light guide 41, but not on the columnar light guide 42. That is, the light emitted from the light source 20 may be incident only on the end surface 41s of the columnar light guide 41, but not on the end surface 42s of the columnar light guide 42.

[0061] In the vehicle lamp 1 of this embodiment, the light guide unit 40 further includes a connecting light guide plate 45 connected to each of the outer peripheral surfaces of the pair of columnar light guides 41, 42. As shown in Fig. 3 , in a cross section perpendicular to the longitudinal direction of the columnar light guide 41, a thickness 60t of the light guide plate 60 at a connection portion 60c with the columnar light guide 41 is smaller than a thickness 45t of the connecting light guide plate 45 at a connection portion 45c with the columnar light guide 41. Therefore, according to the vehicle lamp 1 of this embodiment, it may be more difficult for light to propagate from the columnar light guide 41 to the light guide plate 60, compared to a case where the thickness 60t of the light guide plate 60 at the connection portion 60c with the columnar light guide 41 is larger than the thickness 45t of the connecting light guide plate 45 at the connection portion 45c with the columnar light guide 41. Therefore, compared to the above case, light can be propagated from the columnar light guide 41 to the light guide plate 60 even at a position farther away from the light source 20. From this perspective, it is sufficient that the thickness 60t of the light guide plate 60 at the connection portion 60c in the cross section is equal to or smaller than the thickness 45t of the connection portion 45c of the connecting light guide plate 45. The thickness 60t of the light guide plate 60 at the connection portion 60c in the cross section may be larger than the thickness 45t of the connecting portion 45c of the connecting light guide plate 45.

[0062] In the vehicle lamp 1 of this embodiment, the thickness 45t of the connecting light guide plate 45 is smaller toward the light source 20 side. The vehicle lamp 1 of this embodiment can make it difficult for light to propagate from the columnar light guide 42 to the columnar light guide 41 on the light source 20 side. Therefore, when light from the light source 20 is incident on the light source 20 side of the columnar light guide 42 as in this embodiment, it is possible to make a large amount of light propagate toward the side of the columnar light guide 42 opposite to the light source 20 side. Therefore, it is possible to make it possible for light from the light source 20 to propagate from the columnar light guide 41 to the light guide plate 60 even at a position distant from the light source 20. Note that the thickness 45t of the connecting light guide plate 45 may be larger toward the light source 20 side, or the thickness 45t of the connecting light guide plate 45 may be approximately constant in the longitudinal direction of the columnar light guide 41.

[0063] In the vehicle lamp 1 of this embodiment, the columnar light guide 42 is thicker than the columnar light guide 41. Therefore, according to the vehicle lamp 1 of this embodiment, more light can be propagated to the side opposite to the light source 20 side of the columnar light guide 42 compared to when the columnar light guide 42 is thinner than the columnar light guide 41. Therefore, light from the light source 20 can be propagated from the columnar light guide 41 to the light guide plate 60 even at a position distant from the light source 20. Note that the columnar light guide 42 may be thinner than the columnar light guide 41, or the columnar light guide 42 and the columnar light guide 41 may have the same thickness.

[0064] In the vehicle lamp 1 of this embodiment, the lamp units 10R, 10L further include sub-light sources 31 to 33. The light guide unit 40 further includes light entrance portions 51 to 53 that are connected to the columnar light guide 42 on the side opposite to the light source 20 side from the position where light from the light source 20 is incident, and into which light from the sub-light sources 31 to 33 is incident. The light entrance portions 51 to 53 guide the incident light from the sub-light sources 31 to 33 to the columnar light guide 42 so that the light propagates toward the side opposite to the light source 20 side. Therefore, according to the vehicle lamp 1 of this embodiment, it is possible to increase the amount of light propagating from the columnar light guide 41 to the light guide plate 60 at positions distant from the light source 20, and to prevent positions on the light guide plate 60 far from the light source 20 from becoming dark.

[0065] From this perspective, the vehicle lamp 1 may include at least one sub-light source, and the light guide unit 40 may further include at least one light entrance section having the following configuration. The light entrance section is connected to one of the pair of columnar light guides 41, 42 on the side opposite to the light source 20 side relative to the position where light from the light source 20 is incident, and light from the sub-light source is incident thereon. The light entrance section may be configured to guide the light from the sub-light source that is incident on the light entrance section to the columnar light guide to which the light entrance section is connected so that the light propagates toward the side opposite to the light source 20 side. Therefore, from the above perspective, for example, the number of sub-light sources and light entrance sections may be one, and the light entrance section may be connected to the outer circumferential surface of the columnar light guide 41.

[0066] In the vehicle lamp 1 of this embodiment, the ends of the pair of columnar light guides 41, 42 of the light guide unit 40 in the right lamp unit 10R on the side opposite to the light source 20 are connected to the ends of the pair of columnar light guides 41, 42 of the light guide unit 40 in the left lamp unit 10L on the side opposite to the light source 20. Therefore, according to the vehicle lamp 1 of this embodiment, as described above, light propagating through the pair of columnar light guides 41, 42 of the light guide unit 40 in the right lamp unit 10R can be emitted from the light guide plate 60 of the light guide unit 40 in the left lamp unit 10R. Furthermore, light propagating through the pair of columnar light guides 41, 42 of the light guide unit 40 in the left lamp unit 10L can be emitted from the light guide plate 60 of the light guide unit 40 in the right lamp unit 10R. This can prevent light from the light source 20 from remaining in the columnar light guides 41, 42, thereby improving energy efficiency. Note that the ends of the columnar light guides 41, 42 of the lamp unit 10R opposite to the light source 20 side may be disconnected from the ends of the columnar light guides 41, 42 of the lamp unit 10L opposite to the light source 20 side.

[0067] In the vehicle lamp 1 of this embodiment, an end of the light guide plate 60 of the light guide unit 40 in the right lamp unit 10R opposite the light source 20 side is connected to an end of the light guide plate 60 of the light guide unit 40 in the left lamp unit 10L opposite the light source 20 side. Therefore, according to the vehicle lamp 1 of this embodiment, the range from which light is emitted can be continuously expanded. Note that the end of the light guide plate 60 of the lamp unit 10R opposite the light source 20 side may not be connected to the end of the light guide plate 60 of the lamp unit 10L opposite the light source 20 side.

[0068] Furthermore, the light guide unit 40 of the right lamp unit 10R and the light guide unit 40 of the left lamp unit 10L may be disconnected. For example, the left end of the light guide unit 40 of the lamp unit 10R, which is the end opposite the light source 20, and the right end of the light guide unit 40 of the lamp unit 10L, which is the end opposite the light source 20, may be spaced apart by a predetermined distance. In such a configuration, the sub-light source 31, the sub-light source 32, the sub-light source 33, and the light source 20 may be turned on in this order. Note that the light sources that are turned on continue to be turned on thereafter. With such a configuration, in the light guide unit 40 of the right lamp unit 10R, the light emitting area on the end surface 61 of the light guide plate 60 can be made to extend from the left side, which is opposite the light source 20, to the right side, which is the light source 20 side. In the light guide unit 40 of the left lamp unit 10L, the light emitting area on the end face 61 of the light guide plate 60 can be made to extend from the right side opposite the light source 20 to the left side on the light source 20 side.

[0069] Although the present invention has been described above using the above-mentioned embodiments as examples, the present invention is not limited to these.

[0070] For example, in the above embodiment, the light guide unit 40 has been described with the spacing W between the pair of columnar light guides 41, 42 being substantially constant in the longitudinal direction of the columnar light guide 41. However, the pair of columnar light guides 41, 42 may be arranged in parallel with each other so as to guide light from the light source 20 and to optically connect them in the radial direction. For example, the pair of columnar light guides 41, 42 may be the pair of columnar light guides 41, 42 in the first and second modified examples described below. In the descriptions of the first and second modified examples, the same or equivalent components as those in the above embodiment will be denoted by the same reference numerals and redundant description will be omitted unless otherwise specified.

[0071] First, a first modified example will be described. Fig. 6 is a view similar to Fig. 2 showing the right lamp unit 10R in this modified example. Fig. 7 is a cross-sectional view of the light guide unit 40 taken along line VII-VII in Fig. 6. In this modified example, similar to the above embodiment, the lamp units 10R and 10L have the same configuration except that their shapes are generally symmetrical in the left-right direction. Therefore, only the right lamp unit 10R will be described below.

[0072] As shown in Fig. 6, in a light guide unit 40 of this modification, the configuration of the columnar light guide 42 is different from the configuration of the columnar light guide 42 of the above embodiment. In this modification, the columnar light guide 42 is closer to the columnar light guide 41 on the side opposite to the light source 20 side. In other words, the interval W between the pair of columnar light guides 41, 42 is wider on the light source 20 side. In addition, as shown in Fig. 7, the outer circumferential surfaces of the pair of columnar light guides 41, 42 on the side opposite to the light source 20 side are connected to each other.

[0073] In the vehicle lamp 1 of this modified example, the light emission range of the light guide plate 60 can be widened, as in the above embodiment. Furthermore, in the vehicle lamp 1 of this modified example, the distance between the pair of columnar light guides 41, 42 is wider as it approaches the light source 20. This can make it difficult for light to propagate from the columnar light guide 42 to the columnar light guide 41 on the light source 20 side. Therefore, according to the vehicle lamp 1 of the first modified example, when light from the light source 20 is incident on the light source 20 side of the columnar light guide 42 as in this modified example, it is possible for a large amount of light to propagate to the side of the columnar light guide 42 opposite to the light source 20 side, and it is possible for light to propagate from the columnar light guide 41 to the light guide plate 60 even at a position distant from the light source 20.

[0074] Furthermore, in the vehicle lamp 1 of this modified example, the outer peripheral surfaces of the pair of columnar light guides 41, 42 on the side opposite to the light source 20 side are connected to each other. Therefore, according to the vehicle lamp 1 of this modified example, it is possible to make it difficult for light from the light source 20 to remain on the side of the columnar light guide 42 opposite to the light source 20 side, thereby improving energy efficiency. Note that the outer peripheral surfaces of the pair of columnar light guides 41, 42 on the side opposite to the light source 20 side do not have to be connected to each other.

[0075] Next, a second modified example will be described. Fig. 8 is a view similar to Fig. 2 showing the right lamp unit 10R in this modified example. Fig. 9 is a cross-sectional view of the light guide unit 40 taken along line IX-IX in Fig. 8. In this modified example, similar to the above embodiment, the lamp units 10R and 10L have the same configuration except that their shapes are generally symmetrical in the left-right direction. Therefore, only the right lamp unit 10R will be described below.

[0076] As shown in FIGS. 8 and 9 , the light guide unit 40 of this modification differs from the light guide unit 40 of the above embodiment mainly in that it does not include a connecting light guide plate 45. In this modification, a pair of columnar light guides 41, 42 are optically connected by connecting the outer circumferential surfaces of the pair of columnar light guides 41, 42 to each other. In this modification, a section of the columnar light guide 41 closer to the light source 20 than a section connected to the light guide plate 60 has a tapered shape. The end of the columnar light guide 41 facing the light source 20 is located on the opposite side to the light source 20 side than the end face 42s of the columnar light guide 42. Therefore, the columnar light guide 41 is shorter than the columnar light guide 42. The outer circumferential surface of the columnar light guide 41 is connected to the outer circumferential surface of the columnar light guide 42 over the entire longitudinal direction of the columnar light guide 41. The pair of columnar light guides 41, 42 are thinner on the side opposite to the light source 20 side, and gradually become thinner on the side opposite to the light source 20 side. The pair of columnar light guides 41, 42 may become thinner in stages on the side opposite to the light source 20 side. The thickness of the columnar light guide 42 at any position in the longitudinal direction is thicker than the thickness of the columnar light guide 41 at the same position. The relationship between the thickness of the columnar light guide 41 and the thickness of the columnar light guide 41 is not limited. For example, the columnar light guide 42 may be thinner than the columnar light guide 41 on the side opposite to the light source 20 side.

[0077] In the vehicle lamp 1 of this modified example, the light output range of the light guide plate 60 can be widened, as in the above embodiment. Furthermore, in this modified example, the pair of columnar light guides 41, 42 are thinner on the side opposite to the light source 20 side. Therefore, according to the vehicle lamp 1 of this modified example, light from the light source 20 can be made less likely to remain on the side of the pair of columnar light guides 41, 42 opposite to the light source 20 side, thereby improving energy efficiency. From this perspective, it is only necessary that at least one of the pair of columnar light guides 41, 42 be thinner on the side opposite to the light source 20 side. With this configuration, light from the light source 20 can be made less likely to remain on the side of at least one of the pair of columnar light guides 41, 42 opposite to the light source 20 side, thereby improving energy efficiency.

[0078] Furthermore, the above-described embodiment, the first modified example, and the second modified example may be combined as appropriate. For example, in the above-described embodiment, the columnar light guide 41 may be thinner on the side opposite to the light source 20 side.

[0079] In the above embodiment, the pair of cylindrical columnar light guides 41, 42 extend in the left-right direction and are arranged side by side in the front-rear direction. However, the extending direction of the pair of columnar light guides 41, 42 and the arranging direction of the pair of columnar light guides 41, 42 are not limited. Furthermore, the pair of columnar light guides 41, 42 may be columnar in shape, for example, may be elliptical in shape.

[0080] In the above embodiment, the connecting light guide plate 45 is described as being flat. However, it is only necessary that the connecting light guide plate 45 is connected to the outer peripheral surfaces of the pair of columnar light guides 41, 42 and the pair of columnar light guides 41, 42 are optically connected by the connecting light guide plate 45. For example, the connecting light guide plate 45 may be curved.

[0081] In the above embodiment, the flat light guide plate 60 is described as an example, in which the grooves 62 are provided in the main surface 60s1 and the light is emitted from the end surface 61. However, the light guide plate 60 may be connected to the outer peripheral surface of the columnar light guide 41 and emit light propagating through the columnar light guide 41. For example, the light guide plate 60 may be curved, and the grooves 62 may be provided in the main surface 60s2, or the main surfaces 60s1, 60s2 may not be provided with grooves 62. The light guide plate 60 may emit light from one of the main surfaces 60s1, 60s2, and, for example, the main surface 60s2 may be provided with a step that internally reflects light propagating through the light guide plate 60 toward the main surface 60s1.

[0082] In the above embodiment, the vehicle lamp 1 is described as including a pair of lamp units 10R, 10L. However, the vehicle lamp 1 may be configured with only one of the pair of lamp units 10R, 10L.

[0083] In the above embodiment, the light source 20 and the sub-light sources 31 to 33 emit red light. However, the color of the light emitted by the light source 20 and the sub-light sources 31 to 33 is not limited. For example, the color of the light emitted by the light source 20 and the sub-light sources 31 to 33 may be white. In this case, the light guide unit 40 is made of, for example, red transparent resin or glass.

[0084] In the above embodiment, the lighting units 10R and 10L include the sub-light sources 31 to 33. However, the lighting units 10R and 10L do not necessarily have to include the sub-light sources 31 to 33. In this case, for example, the light guide unit 40 does not include the light entrance portions 51 to 53.

[0085] In the above embodiment, the vehicle lamp 1 is a tail 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 turn lamp, a stop lamp, or the like, or may be any of these lamps for a two-wheeled vehicle. [Industrial Applicability]

[0086] According to the present invention, a vehicle lamp capable of widening the range over which light is emitted from a light guide plate is provided, and can be used in fields such as vehicle lamps for automobiles and the like. [Explanation of symbols]

[0087] 1. Vehicle lighting fixture 10R, 10L... Lighting unit 20...Light source 31~33 Sub-light source 40 Light guide unit 41,42...Columnar light guide 45....Connecting light guide plate 51 to 53: Light receiving section 60...Light guide plate

Claims

1. The lamp unit includes a light source, a pair of columnar light guides arranged in parallel to each other so as to guide light from the light source and optically connect them in the radial direction, and a light guide unit including a light guide plate connected to the outer peripheral surface of one of the columnar light guides and emitting light propagating through the one columnar light guide. A vehicle lamp characterized by:

2. The light guide unit further includes a connecting light guide plate connected to each of the outer peripheral surfaces of the pair of columnar light guides.

2. A vehicle lamp according to claim 1.

3. In a cross section perpendicular to the longitudinal direction of the one columnar light guide, the thickness of the light guide plate at the connection portion with the one columnar light guide is equal to or smaller than the thickness of the connecting light guide plate at the connection portion with the one columnar light guide.

3. A vehicle lamp according to claim 2.

4. The thickness of the connecting light guide plate is smaller toward the light source side.

3. A vehicle lamp according to claim 2.

5. The distance between the pair of columnar light guides is wider toward the light source.

3. A vehicle lamp according to claim 2.

6. The outer peripheral surfaces of the pair of columnar light guides on the side opposite to the light source side are connected to each other.

6. A vehicle lamp according to claim 5.

7. The pair of columnar light guides are optically connected by connecting the outer circumferential surfaces of the pair of columnar light guides to each other.

2. A vehicle lamp according to claim 1.

8. The amount of light from the light source incident on the other columnar light guide is greater than the amount of light from the light source incident on one columnar light guide.

2. A vehicle lamp according to claim 1.

9. The other columnar light guide is thicker than the one columnar light guide.

2. A vehicle lamp according to claim 1.

10. At least one of the pair of columnar light guides is tapered toward the side opposite to the light source.

2. A vehicle lamp according to claim 1.

11. The lighting unit further includes at least one sub-light source, the light guide unit further includes at least one light entrance portion connected to one of the pair of columnar light guides on a side opposite to the light source side with respect to a position where the light from the light source is incident, and into which the light from the sub-light source is incident, The light incident portion guides the light from the sub-light source incident on the light incident portion to the columnar light guide to be connected to the light incident portion so as to propagate toward the opposite side to the light source side.

2. A vehicle lamp according to claim 1.

12. A pair of the lamp units is provided, An end portion of the pair of columnar light guides of the light guide unit in one of the lamp units opposite to the light source side is connected to an end portion of the pair of columnar light guides of the light guide unit in the other lamp unit opposite to the light source side.

2. A vehicle lamp according to claim 1.

13. an end portion of the light guide plate of the light guide unit in the one lamp unit opposite to the light source side is connected to an end portion of the light guide plate of the light guide unit in the other lamp unit opposite to the light source side; 13. A vehicle lamp according to claim 12.

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