Vehicle lamp

Abstract

To provide a lamp for a vehicle which can make its appearance favorable at lighting by preventing the occurrence of luminance unevenness.SOLUTION: A lamp 1A for a vehicle comprises a light source 2 and a rod-shaped light guide body 3A, makes light L emitted from the light source 2 incident into the light guide body 3A from an incident part 4 which is arranged at a base end side of the light guide body 3A, guides the light L toward a tip side of the light guide body 3A, and makes a light emitting part 6 arranged at a front face side of the light guide body 3A emit light by emitting the light L reflected by a plurality of reflection cuts 5a provided at a back face side of the light guide body 3A to the outside of the light guide body 3A from the front face side of the light guide body 3A. The lamp has a curved part 7 in which a part of the light guide body 3A is curved between the incident part 4 and the light emitting part 6, and an erecting wall 9 which erects from a front face side of the curved part 7 by notching a part of the front face side of the curved part 7 in an axial line direction. The erecting wall 9 forms a reflection face for reflecting the light L which is guided in the curved part 7.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to vehicle lamps.

Background Art

[0002] Conventionally, as a vehicle lamp mounted on a vehicle, a combination of a light source such as a light-emitting diode (LED) and a rod-shaped light guide (light guide rod) is known (for example, see Patent Document 1 below).

[0003] In such a vehicle lamp, the light emitted from the light source enters the inside of the light guide from an incident portion provided on the base end side of the light guide, and while repeatedly reflecting inside the light guide, the light is guided toward the tip end side of the light guide. Further, the light reflected by a plurality of reflection cuts provided on the back side of the light guide is emitted from the front side of the light guide to the outside of the light guide. Thereby, it is possible to linearly emit light from a light-emitting portion provided on the front side of the light guide.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in recent vehicle lamps, due to the diversification of designs, for example, designs in which a direction indicator (winker lamp, turn lamp), a side marker lamp (position lamp), a daytime running lamp (DRL), etc. emit linear light are increasing.

[0006] However, in the above-described rod-shaped light guide, due to the difference in the optical path length of the light guided from the base end side to the tip end side, luminance unevenness may occur in the light emitting portion. That is, when luminance unevenness occurs in the light emitting portion of the light guide, in the axial direction of the light guide, the tip end side where the optical path length from the light source is longer becomes relatively darker due to light attenuation than the base end side where the optical path length from the light source is shorter. Therefore, such brightness contrast is recognized as luminance unevenness in the light emitting portion.

[0007] For this reason, when the rod-shaped light guide emits light in a line shape, problems such as deterioration of the lighting feeling, such as a decrease in the visibility and appearance of the light emitting portion due to the occurrence of the above-described luminance unevenness, have become an issue.

[0008] In particular, when a curved portion where a part of the light guide is curved is provided between the incident portion and the light emitting portion, if the length of this curved portion is short and the curvature is small, a part of the light guided inside the curved portion may not go toward the tip end side of the light guide and may become stray light and leak outside from the base end side of the light emitting portion. In this case, a part of the base end side of the light emitting portion appears to shine more strongly than the surroundings, and the appearance during lighting of the vehicle lamp deteriorates due to so-called spotlights.

[0009] The present invention has been proposed in view of such conventional circumstances, and an object thereof is to provide a vehicle lamp capable of improving the appearance during light emission by preventing the occurrence of luminance unevenness.

Means for Solving the Problems

[0010] To achieve the above object, the present invention provides the following means. 〔1〕 A vehicle lamp including a light source and a rod-shaped light guide, the light emitted from the light source is incident into the light guide from an incident portion provided on the base end side of the light guide, the light is guided toward the tip end side of the light guide, and the light reflected by a plurality of reflection cuts provided on the back side of the light guide is emitted from the front side of the light guide to the outside of the light guide, thereby causing a light emitting portion provided on the front side of the light guide to emit light, A curved portion where a part of the light guide is curved between the incident portion and the light emitting portion, and a standing wall that rises from the front side of the curved portion by cutting out a part of the front side of the curved portion in the axial direction. The standing wall forms a reflecting surface that reflects light guided inside the curved portion, and is a vehicle lamp characterized by this. 〔2〕 The vehicle lamp according to 〔1〕 above, characterized in that two of the standing walls are provided facing each other at the central portion on the front side of the curved portion. 〔3〕 The vehicle lamp according to 〔2〕 above, characterized in that the standing walls are provided on both side surfaces of a convex portion formed by cutting out both sides of the central portion on the front side of the curved portion in the axial direction. 〔4〕 The vehicle lamp according to 〔2〕 above, characterized in that the standing walls are provided on both side surfaces of a concave portion formed by cutting out the central portion on the front side of the curved portion in the axial direction. 〔5〕 The vehicle lamp according to any one of 〔1〕 to 〔4〕 above, characterized in that a plurality of diffusion reflection cuts are provided on the front side of the curved portion. 〔6〕 The vehicle lamp according to 〔5〕 above, characterized in that the plurality of diffusion reflection cuts extend in the axial direction of the curved portion and are constituted by a plurality of serrations arranged in a direction orthogonal to the axial direction of the curved portion.

Effect of the Invention

[0011] As described above, according to the present invention, it is possible to provide a vehicle lamp that can improve the appearance during light emission by preventing the occurrence of brightness unevenness.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

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Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, for the sake of easy viewing of each component, the scale of the dimensions may be made different depending on the component, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0014] (First Embodiment) First, as the first embodiment of the present invention, for example, the vehicle lamp 1A shown in FIGS. 1 to 7 will be described.

[0015] Note that FIG. 1 is a front view showing the configuration of the vehicle lamp 1A. FIG. 2 is a top view showing the configuration of the vehicle lamp 1B. FIG. 3 is a cross-sectional view of the light guide body 3A along the line segment A-A shown in FIG. 1. FIG. 4 is a cross-sectional view of the light guide body 3A with the enclosed portion B shown in FIG. 3 enlarged. FIG. 5 is a cross-sectional view of the light guide body 3A along the line segment C-C shown in FIG. 2. FIG. 6 is a cross-sectional view of the light guide body 3A along the line segment D-D shown in FIG. 2. FIG. 7 is a cross-sectional view of the light guide body 3A along the line segment E-E shown in FIG. 2.

[0016] In the drawings shown below, an XYZ orthogonal coordinate system is set, and the X-axis direction is the front-rear direction of the vehicle lamp 1A, the Y-axis direction is the left-right direction of the vehicle lamp 1A, and the Z-axis direction is the up-down direction of the vehicle lamp 1A, and they are respectively shown as such.

[0017] As shown in FIGS. 1 and 2, the vehicle lamp 1 of this embodiment includes a light source 2 and a rod-shaped light guide 3A. The light L emitted from the light source 2 is incident into the inside of the light guide 3A from an incident portion 4 provided on the base end side of the light guide 3A, and the light L is guided toward the tip end side of the light guide 3A. At the same time, the light L reflected by a plurality of reflection cuts 5a provided on the back side of the light guide 3A is emitted from the front side of the light guide 3A to the outside of the light guide 3A, thereby causing the light emitting portion 6 provided on the front side of the light guide 3A to emit light.

[0018] The light source 2 is made of, for example, an LED, and is mounted on the surface of a circuit board (not shown) provided with a drive circuit for driving this LED, and emits the light L radially toward the base end side of the light guide 3.

[0019] The light guide 3A is made of a light transmissive member such as a transparent resin such as polycarbonate or acrylic, or glass.

[0020] The incident portion 4 is located on the base end side of the light guide 3A and has a flat (planar) incident surface 4a facing the light source 2. The incident portion 4 allows the light L emitted from the light source 2 to enter the inside of the light guide 3A from this incident surface 4a. Note that the incident portion 4 is not limited to the configuration having the above-described flat (planar) incident surface 4a, and may have a lens shape that allows the light L emitted radially from the light source 2 to enter the inside of the light guide 3A while being parallelized or condensed.

[0021] As shown in FIGS. 3 and 4, the plurality of reflection cuts 5a only need to reflect the light L incident on the back side of the light guide 3A at an angle that allows the light L to be emitted (transmitted) from the front side of the light guide 3A to the outside, and the shape, size, number, etc. thereof are not particularly limited.

[0022] In this embodiment, for example, a reflection cut 5a having a substantially triangular cross-section formed by notching the central portion on the back side of the light guide 3A in the vertical direction (the up-and-down direction in this embodiment) perpendicular to the axial direction of the light guide 3A is arranged in the axial direction of the light guide 3A (the left-and-right direction in this embodiment).

[0023] Also, in order to make the light-emitting part 6 described later emit light more uniformly in the axial direction of the light guide 3A, the plurality of reflection cuts 5a have gradually decreasing intervals between adjacent ones from the base end side to the tip end side of the light guide 3A.

[0024] On both sides sandwiching the central portion (the plurality of reflection cuts 5a) on the back side of the light guide 3A, a pair of reflecting surfaces 5b are provided. The pair of reflecting surfaces 5b are constituted by concave curved surfaces that are arcuately curved in a vertical cross-section (hereinafter referred to as "vertical cross-section") perpendicular to the axial direction of the light guide 3A.

[0025] As shown in FIGS. 1, 2, and 7, the light-emitting part 6 is located on the front side of the light guide 3A and has an emission surface 6a that is continuous in the axial direction of the light guide 3A. The emission surface 6a is constituted by a convex curved surface that is arcuately curved in the vertical cross-section of the light guide 3A.

[0026] Note that the emission surface 6a may be configured to be provided with a plurality of diffusion cuts (not shown) for diffusing the light L emitted from the emission surface 6a to the outside. Examples of the diffusion cuts include lens cuts such as flute cuts and fisheye cuts, and uneven structures formed by performing processes such as knurling and embossing. Also, by adjusting the shape and the like of the diffusion cuts, it is possible to control the degree of diffusion of the light L emitted from the emission surface 6a.

[0027] Incidentally, as shown in FIGS. 1 and 2, the vehicle lamp 1 of the present embodiment has a curved portion 7 where a part of the light guide 3A is curved between the incident portion 4 and the light emitting portion 6, and an extension portion 8 provided with a plurality of reflection cuts 5a and the light emitting portion 6. That is, the light guide 3A has an elongated shape that extends forward from the position facing the light source 2, is curved by the curved portion 7, and then the extension portion 8 extends in the vehicle width direction.

[0028] Regarding the angle range of curvature of the curved portion 7, it is preferably 60° or more, and regarding the curvature of the curved portion 7, it is preferably R18.5 or more on its central axis.

[0029] Further, as shown in FIGS. 1, 2, and 6, the light guide 3A has a pair (two) of standing walls 9 that rise from the front side of the curved portion 7 by cutting both sides sandwiching the central portion on the front side of the curved portion 7 in the axial direction.

[0030] The pair of standing walls 9 are provided on both side surfaces of a convex portion 10 formed by cutting both sides sandwiching the central portion on the front side of the curved portion 7 in the axial direction. That is, these pair of standing walls 9 rise parallel from the front side of the curved portion 7 in a state of facing each other on both side surfaces of the convex portion 10.

[0031] Regarding the pair of standing walls 9, they are not limited to those rising parallel to each other on both side surfaces of the convex portion 10 described above, and they may be inclined to each other. Further, the pair of standing walls 9 are not limited to planes, and may be curved surfaces curved convexly or concavely with respect to each other.

[0032] Further, on the front side of the curved portion 7, as shown in FIGS. 1, 2, 5, and 6, in order to make the light emitting portion 6 emit light more uniformly in the vertical direction of the light guide 3A, a plurality of diffusion reflection cuts 11 that reflect the light L guided inside the curved portion 7 while diffusing it in the vertical direction of the light guide 3A are provided.

[0033] The plurality of diffusion reflection cuts 11 extend in the axial direction of the curved portion 7 and are formed by a plurality of serrations arranged in a direction orthogonal to the axial direction of the curved portion 7. That is, each diffusion reflection cut 11 is formed by a convex curved surface that is arcuately curved in the vertical cross-section of the light guide 3A. Note that the diffusion reflection cut 11 is not limited to the configuration in which the above-described convex serrations are arranged, and may be a configuration in which concave serrations are arranged, or a configuration in which these convex and concave serrations are alternately arranged.

[0034] In the vehicle lamp 1A of the present embodiment having the above-described configuration, as shown in FIG. 6, the pair of standing walls 9 described above form a reflecting surface that reflects the light L guided inside the curved portion 7. Thereby, even when the length of the curved portion 7 is short and the curvature is small, a part of the light L guided inside the curved portion 7 is prevented from leaking to the outside from the base end side of the light emitting portion 6 as stray light without going toward the tip side of the light guide 3A, and it is possible to guide the light toward the tip side of the light guide 3A.

[0035] Therefore, in the vehicle lamp 1A of the present embodiment, it is possible to prevent the occurrence of luminance unevenness in the light emitting portion 6 due to so-called point light emission in which a part of the base end side of the light emitting portion 6 described above appears to shine more strongly than the surroundings.

[0036] Here, as an example, the light source image of the light emitting portion 6 when the light guide 3A is made to emit light was obtained by simulation. The light source image of the light emitting portion according to the simulation result is shown in FIG. 8.

[0037] On the other hand, as a comparative example, the light source image of the light emitting portion 6 when a light guide having substantially the same shape as the above-described light guide 3A was made to emit light was obtained by simulation, except that the pair of standing walls 9 located on the front side of the curved portion 7 was omitted (the curved portion 7 has the uniform cross-sectional shape shown in FIG. 5). The light source image of the light emitting portion according to the simulation result is shown in FIG. 9.

[0038] In the light guide 3A serving as an example, as shown in FIG. 8, it can be seen that there is no generation of point light, and the light emitting portion 6 emits light uniformly. On the other hand, in the light guide serving as a comparative example, as shown in FIG. 9, it can be seen that point light is generated on the proximal end side of the light emitting portion 6.

[0039] As described above, in the vehicle lamp 1A of the present embodiment, the light emitting portion 6 can emit light more uniformly, and it is possible to improve the appearance when the light emitting portion 6 emits light.

[0040] (Second Embodiment) Next, as a second embodiment of the present invention, for example, a vehicle lamp 1B shown in FIG. 10 will be described. Note that FIG. 10 is a cross-sectional view of a light guide 3B included in the vehicle lamp 1B. In the following description, for parts equivalent to those of the vehicle lamp 1A, the description will be omitted and the same reference numerals will be used in the drawings.

[0041] The vehicle lamp 1B of the present embodiment includes a light guide 3B as shown in FIG. 10 instead of the light guide 3A. Otherwise, it has basically the same configuration as the vehicle lamp 1A.

[0042] Specifically, in this light guide 3B, as shown in FIG. 10, a pair (two) of standing walls 9 are provided on both side surfaces of a recess 12 formed by cutting out the central portion on the front side of the curved portion 7 in the axial direction. That is, these pair of standing walls 9 are formed to stand up in parallel from the front side of the curved portion 7 in a state of facing each other on both side surfaces of the recess 12.

[0043] In the vehicle lamp 1B of the present embodiment having the above-described configuration, the pair of standing walls 9 described above form a reflecting surface that reflects the light L guided inside the curved portion 7. Thereby, even when the length of the curved portion 7 is short and the curvature is small, a part of the light L guided inside the curved portion 7 is prevented from leaking to the outside from the proximal end side of the light emitting portion 6 as stray light without heading toward the distal end side of the light guide 3A, and it is possible to guide the light toward the distal end side of the light guide 3A.

[0044] Therefore, in the vehicle lamp 1B of the present embodiment, it is possible to prevent the occurrence of luminance unevenness in the light emitting portion 6 by the so-called point light, in which a part of the proximal end side of the above-described light emitting portion 6 appears to emit light more strongly than the surroundings.

[0045] As described above, in the vehicle lamp 1B of the present embodiment, the light emitting portion 6 can emit light more uniformly, and it is possible to improve the appearance when the light emitting portion 6 emits light.

[0046] Note that the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, regarding the above-described vertical wall 9, both side surfaces of the convex portion 10 formed by cutting both sides sandwiching the central portion on the front side of the above-described curved portion 7 in the axial direction, or both side surfaces of the concave portion 12 formed by cutting the central portion on the front side of the curved portion 7 in the axial direction are provided in a pair (two). However, by providing at least one or more vertical walls 9, it is possible to obtain the effect of the reflecting surface by the above-described vertical wall 9. Further, by providing a plurality of the above-described convex portions 10 or concave portions 12, it is also possible to increase the number of vertical walls 9.

[0047] In addition, in the above-described vehicle lamps 1A and 1B, a configuration in which a reflector facing the back surfaces of the light guides 3A and 3B may be arranged. In the case of this configuration, the light L emitted from the back side of the light guides 3A and 3B to the outside is reflected by the reflector and made to enter the inside from the back side of the light guides 3A and 3B again, whereby it is possible to improve the utilization efficiency of the light L.

[0048] Also, in the above-described vehicle lamp 1, it is possible to appropriately change the shape of the above-described light guides 3A and 3B in accordance with the design of an actual vehicle or the like. For example, the above-described light guides 3A and 3B may have a shape that curves or inclines in a direction in which the outside is recessed more than the inside in the vehicle width direction in accordance with the slant shape provided at the corner portion on the front end or rear end side of the vehicle.

[0049] Note that the vehicle lamp to which the present invention is applied is not particularly limited. For example, it can be widely applied to the present invention, such as a tail lamp (tail lamp), a position lamp (position lamp), a daytime running lamp (DRL), a back lamp, a direction indicator (winker lamp), a side marker lamp, and the like.

[0050] In addition, the light source 2 only needs to emit light L radially. In addition to the above-described LEDs, light-emitting elements such as laser diodes (LDs) can be used. Further, the color of the light emitted by the light source 2 can be appropriately changed according to the use of the vehicle lamp, such as red light, white light, orange light, and the like.

Explanation of Signs

[0051] 1A, 1B... Vehicle lamp 2... Light source 3A, 3B... Light guide 4... Incident part 5a... Reflection cut 6... Light emitting part 7... Curved part 8... Extension part 9... Standing wall 10... Protrusion 11... Diffuse reflection cut 12... Recess L... Light

Claims

1. A vehicle lamp comprising a light source and a rod-shaped light guide, wherein light emitted from the light source enters the interior of the light guide from an incident portion provided on the proximal end side of the light guide, the light is guided toward the distal end side of the light guide, and light reflected by a plurality of reflection cuts provided on the back side of the light guide is emitted from the front side of the light guide to the outside of the light guide, thereby causing a light-emitting portion provided on the front side of the light guide to emit light. A curved portion in which a part of the light guide is curved between the incident portion and the light-emitting portion. It has a standing wall that rises from the front side of the curved portion by cutting out a part of the front side of the curved portion in the axial direction. The vehicle lamp is characterized in that the standing wall forms a reflecting surface for reflecting light guided inside the curved portion.

2. The vehicle lamp according to claim 1, characterized in that two of the standing walls are provided facing each other at the central portion on the front side of the curved portion.

3. The vehicle lamp according to claim 2, characterized in that the standing walls are provided on both side surfaces of a convex portion formed by cutting out both sides of the central portion on the front side of the curved portion in the axial direction.

4. The vehicle lamp according to claim 2, characterized in that the standing walls are provided on both side surfaces of a concave portion formed by cutting out the central portion on the front side of the curved portion in the axial direction.

5. The vehicle lamp according to any one of claims 1 to 4, characterized in that a plurality of diffusion reflection cuts are provided on the front side of the curved portion.

6. The vehicle lamp according to claim 5, characterized in that the plurality of diffusion reflection cuts extend in the axial direction of the curved portion and are constituted by a plurality of serrations arranged in a direction orthogonal to the axial direction of the curved portion.

Images