Vehicular lighting fixture

Abstract

To provide a vehicular lighting fixture capable of allowing a large area to emit light with fewer light sources.SOLUTION: A vehicular lighting fixture includes: an LED 12; and a tabular light guide body including a light entering part 22 where light from the LED 12 enters, and a light emitting part 24 for emitting light from the light entering part 22. The light entering part 22 includes: an incident part 30 for allowing the light from the LED 12 to enter the light entering part 22; a first reflection part 32 for radially reflecting the light which has entered from the incident part 30; a second reflection part 34 for reflecting the light advancing in the direction being separated from the light emitting part 24 out of the light reflected by the first reflection part 32, as parallel light; and a third reflection part 36 for reflecting the parallel light from the second reflection part 34 toward the light emitting part 24.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Vehicle lamps have been proposed that combine a light source such as an LED with a plate-shaped light guide that controls the light from the light source. In such vehicle lamps, light emitted from the light source enters the light guide from a light entrance portion of the plate-shaped light guide, travels through the light guide, and is emitted forward from the light-emitting surface of the light guide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-91825 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-6091 Summary of the Invention [Problem to be solved by the invention]

[0004] In vehicle lighting fixtures that use light sources such as LEDs and a plate-shaped light guide, if you want to illuminate a large area, one method would be to use multiple light sources to direct light into the plate-shaped light guide, but this poses a cost issue.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle lamp that can emit light over a large area using a small number of light sources. [Means for solving the problem]

[0006] In order to solve the above problems, one embodiment of the present invention provides a vehicle lamp including a light source, a plate-shaped light guide including a light entrance portion that receives light from the light source, and a light emission portion that emits light from the light entrance portion. The light entrance portion includes an entrance portion that receives light from the light source and enters the light entrance portion, a first reflection portion that radially reflects the light that has entered from the entrance portion, a second reflection portion that reflects, as parallel light, light that has been reflected by the first reflection portion and that travels away from the light emission portion, and a third reflection portion that reflects the parallel light from the second reflection portion toward the light emission portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a vehicle lamp that can emit light over a large area using a small number of light sources. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic front view of a vehicle lamp according to an embodiment of the present invention; [Figure 2] 2 is a schematic vertical cross-sectional view AA of the vehicle lamp shown in FIG. 1. [Figure 3] 1 is a schematic perspective view of a light entrance portion of a plate-shaped light guide as viewed from diagonally above the rear side of the lighting fixture. FIG. [Figure 4] 3 is a schematic perspective view of a light entrance portion of a plate-shaped light guide as viewed from diagonally below the front side of the lighting fixture. FIG. [Figure 5] FIG. [Figure 6] 6 is a schematic cross-sectional view of the light incident part shown in FIG. 5. FIG. [Figure 7] 6 is a CC schematic cross-sectional view of the light incident part shown in FIG. 5. FIG. [Figure 8] FIG. 6 is a DD schematic cross-sectional view of the light incident part shown in FIG. 5. [Figure 9] FIG. 2 is an enlarged schematic perspective view of a total reflection portion of a plate-shaped light guide. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below based on preferred embodiments with reference to the drawings. The following configurations are for illustrative purposes only to facilitate understanding of the present disclosure, and the scope of the present disclosure is defined solely by the appended claims. Identical or equivalent components and members shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The dimensions of the components in each drawing are enlarged or reduced as appropriate for ease of understanding. Some components that are not important for explaining the embodiments are omitted from the drawings. Furthermore, when terms indicating directions, such as "up," "down," "front," "rear," "left," "right," "inside," and "outside," are used in this specification, they refer to the directions in the position of the vehicular lamp when mounted on a vehicle.

[0010] Fig. 1 is a schematic front view of a vehicle lamp 10 according to an embodiment of the present invention. Fig. 2 is a schematic longitudinal cross-sectional view taken along line AA of the vehicle lamp 10 shown in Fig. 1. The vehicle lamp 10 is a lamp having a relatively large light-emitting surface. The vehicle lamp 10 can be used, for example, as a grill lamp, tail lamp, daytime running lamp, clearance lamp, turn signal lamp, etc.

[0011] As shown in Figures 1 and 2, the vehicle lamp 10 comprises an LED 12 as a light source, a substrate 14, a plate-shaped light guide 16 that receives light from the LED 12 and emits it forward of the lamp, a reflector 18 provided behind the plate-shaped light guide 16, and an extension 20 provided to surround the periphery of the plate-shaped light guide 16.

[0012] The LED 12 is mounted on a substrate 14 and emits light when supplied with current from the substrate 14. In this embodiment, the LED 12 is disposed so that its optical axis Ax faces diagonally downward. As shown in FIG. 2, a bracket portion 18a is provided at the lower end of the reflector 18. The substrate 14 is supported by the bracket portion 18a.

[0013] The plate-shaped light guide 16 includes a light-entering section 22 that receives light from the LEDs 12, a light-emitting section 24 that emits light from the light-entering section 22, and a total reflection section 26 that is provided between the light-entering section 22 and the light-emitting section 24 and that totally reflects the light from the light-entering section 22 toward the light-emitting section 24. The plate-shaped light guide 16 is made of a transparent resin material such as acrylic or polycarbonate.

[0014] The light-emitting section 24 is formed in a plate shape. The front surface of the light-emitting section 24 is a light-emitting surface 24a. In this embodiment, the light-emitting surface 24a has a rectangular shape when viewed from the front, as shown in FIG. 1, but the shape is not particularly limited. A back surface 24b of the light-emitting section 24 is formed with a plurality of steps for reflecting and refracting light that enters and travels inside the light-emitting section 24 and emitting it forward of the lamp.

[0015] In this embodiment, the light entrance portion 22 is provided at the bottom of the plate-shaped light guide 16. As shown in Fig. 2, the light entrance portion 22 is formed by bending the bottom of the plate-shaped light guide 16 toward the rear of the lamp. The light entrance portion 22, together with the LED 12 and the board 14, is housed in the space formed by the bracket portion 18a and the extension 20.

[0016] The configuration of the light entrance section 22 will be described in detail below. Fig. 3 is a schematic perspective view of the light entrance section 22 of the plate-shaped light guide 16 as seen from diagonally above the rear side of the lamp. Fig. 4 is a schematic perspective view of the light entrance section 22 of the plate-shaped light guide 16 as seen from diagonally below the front side of the lamp. Figs. 3 and 4 show two light entrance sections 22 formed side by side in the width direction of the lamp. LEDs 12 (not shown in Figs. 3 and 4) are arranged for each of these two light entrance sections 22. Fig. 5 is a schematic top view of the light entrance section 22. Fig. 5 illustrates an example of the LEDs 12 and an example of the optical path of the light emitted from the LEDs 12.

[0017] The light incident portion 22 has a generally plate-like shape. The light incident portion 22 has an upper surface 22a facing the LED 12, a lower surface 22b opposite the upper surface 22a, and a rear end surface 22c facing rearward of the lamp. The front end of the light incident portion 22 is connected to the lower end of the light emitting portion 24 via a total reflection portion 26 formed as a bent portion.

[0018] The light entrance section 22 has an incident section 30 on the upper surface 22a, which allows light from the LED 12 to enter the light entrance section 22. The incident section 30 is formed as a stepped surface that protrudes from the upper surface 22a.

[0019] The light entrance section 22 also has a first reflecting section 32 on its lower surface 22b that radially reflects light that has entered the light entrance section 22 from the incident section 30. The first reflecting section 32 is provided at a position facing the incident section 30, and is formed as a recess by recessing the lower surface 22b of the light entrance section 22 inward. In this embodiment, the first reflecting section 32 is formed to have a cone-shaped reflecting surface. The LED 12 is positioned so that its optical axis Ax coincides with the central axis of the first reflecting section 32.

[0020] The light incident unit 22 also includes a second reflecting unit 34 at a portion of the rear end face 22c close to the first reflecting unit 32, which reflects, as parallel light, light that is reflected by the first reflecting unit 32 and travels in a direction away from the light emitting unit 24. The second reflecting unit 34 is formed as a parabolic reflecting surface.

[0021] The light incident section 22 also includes a third reflecting section 36 at a portion of the rear end face 22c far from the first reflecting section 32, which reflects a portion of the parallel light from the second reflecting section 34 toward the light emitting section 24. The third reflecting section 36 is formed as a multi-step reflecting surface in which a plurality of minute reflecting surfaces are connected in a staircase pattern.

[0022] Furthermore, the light entrance section 22 includes a fourth reflecting section 38 disposed between the second reflecting section 34 and the third reflecting section, which reflects a portion of the parallel light from the second reflecting section 34 toward the light emission section 24. The fourth reflecting section 38 is formed as a triangular recess formed by recessing the lower surface 22b of the light entrance section 22 inward. The height of the fourth reflecting section 38 (i.e., the depth of the recess) is set smaller than the thickness of the light entrance section 22. In other words, the fourth reflecting section 38 is not a recess that penetrates the light entrance section 22, but is recessed partway through the thickness of the light entrance section 22 (for example, halfway through the thickness).

[0023] The first reflecting portion 32, the second reflecting portion 34, the third reflecting portion 36 and the fourth reflecting portion 38 are formed symmetrically on either side of a cross section of the lamp in the front-rear direction (cross section BB in FIG. 5) that includes the optical axis Ax of the LED 12.

[0024] Next, light emission in the vehicle lamp 10 according to this embodiment will be described. FIG. 6 is a schematic cross-sectional view (BB) of the light entrance portion 22 shown in FIG. 5 (a cross-sectional view including the optical axis Ax of the LED 12). As shown in FIG. 5, light emitted from the LED 12 enters the light entrance portion 22 from the incident portion 30 and is radially reflected within the light entrance portion 22 by the first reflecting portion 32. Of the radially reflected light, light traveling in a direction toward the light-emitting portion 24 is totally reflected by the total reflecting portion 26 and travels within the light-emitting portion 24. The light traveling within the light-emitting portion 24 is reflected and refracted by a plurality of concave steps 24c formed on the back surface 24b of the light-emitting portion 24 and is emitted forward of the lamp from the light-emitting surface 24a. The light traveling along such an optical path is illustrated as light L1 in FIGS. 5 and 6.

[0025] FIG. 7 is a CC schematic cross-sectional view (cross-sectional view including the fourth reflecting portion 38) of the light entrance portion 22 shown in FIG. 5 . As shown in FIG. 5 , of the radially reflected light reflected by the first reflecting portion 32, light traveling in a direction away from the light-emitting portion 24 is reflected by the second reflecting portion 34 as parallel light in the width direction of the light entrance portion 22 (a direction perpendicular to the front-to-rear direction of the lamp). As shown in FIG. 7 , in this embodiment, the height (depth) of the fourth reflecting portion 38 is half the thickness of the light entrance portion 22. That is, the fourth reflecting portion 38 is located in the lower half of the light entrance portion 22 in the thickness direction. Therefore, of the parallel light from the second reflecting portion 34, light traveling in the lower half of the light entrance portion 22 in the thickness direction is reflected by the fourth reflecting portion 38 toward the light-emitting portion 24. This light is totally reflected by the total reflecting portion 26 and travels into the light-emitting portion 24. The light traveling inside the light-emitting section 24 is reflected and refracted by a plurality of concave steps 24c formed on the back surface 24b of the light-emitting section 24, and is emitted forward of the lamp from the light-emitting surface 24a. The light traveling along such an optical path is illustrated as light L2 in Figures 5 and 7.

[0026] FIG. 8 is a DD schematic cross-sectional view (cross-sectional view including the third reflecting portion 36) of the light entrance portion 22 shown in FIG. 5. Of the parallel light from the second reflecting portion 34, light traveling in the upper half of the light entrance portion 22 in the plate thickness direction passes through the fourth reflecting portion 38 without being reflected therethrough and reaches the third reflecting portion 36. The light incident on the third reflecting portion 36 is reflected by the third reflecting portion 36 toward the light emitting portion 24. This light is totally reflected by the total reflecting portion 26 and travels inside the light emitting portion 24. The light traveling inside the light emitting portion 24 is reflected and refracted by multiple concave steps 24c formed on the back surface 24b of the light emitting portion 24 and is emitted forward from the light emitting surface 24a of the light emitting portion 24. The light traveling along such an optical path is illustrated as light L3 in FIGS. 5 and 8.

[0027] Thus, the light entrance section 22 configured as in this embodiment can guide the light beams L2 and L3, which are reflected by the first reflecting section 32 and then travel in a direction away from the light-emitting section 24, to the light-emitting section 24. This, combined with the light beam L1, which is reflected by the first reflecting section 32 and then travels directly toward the light-emitting section 24, allows the light beams to be guided to a wide area of ​​the light-emitting section 24. Since the light-emitting area of ​​a single LED 12 is increased, the vehicle lamp 10 as a whole can emit light over a large area with a small number of light sources. Furthermore, the light entrance section 22 according to this embodiment can guide the light beams to a wide area of ​​the light-emitting section 24, thereby improving the uniformity of the light emitted from the light-emitting section 24. Furthermore, the light entrance section 22 according to this embodiment can effectively guide the light emitted from the LED 12 to the light-emitting section 24, thereby improving light utilization efficiency.

[0028] FIG. 9 is an enlarged schematic perspective view of the total reflection portion 26 of the plate-shaped light guide 16. As described above, the total reflection portion 26 is provided between the light incident portion 22 and the light-emitting portion 24 and is configured to totally reflect light from the light incident portion 22 toward the light-emitting portion 24. In this embodiment, the total reflection portion 26 is formed with a plurality of cylindrical steps 40 that diffuse the totally reflected light. By providing such cylindrical steps 40 in the total reflection portion 26, light from the light incident portion 22 can be guided not only to a region of the light-emitting portion 24 close to the light incident portion 22 but also to a region distant from the light incident portion 22. As a result, so-called "point light," in which a part of the light-emitting portion 24 emits locally strong light, is suppressed, and the uniformity of light emission in the light-emitting portion 24 can be further improved. The steps formed in the total reflection portion 26 are not limited to cylindrical steps and may be, for example, fisheye steps.

[0029] In the above-described embodiment, the light entrance portion 22 is formed by bending the lower portion of the plate-shaped light guide 16 toward the rear of the lamp. However, in another embodiment, the light entrance portion may be formed without bending a portion of the plate-shaped light guide. That is, the light entrance portion may be formed so as to extend parallel to the light-emitting portion. In this case, too, light can be guided to a wide area of ​​the light-emitting portion, so that the entire vehicle lamp can emit light over a large area with a small number of light sources.

[0030] The present invention has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention. [Explanation of symbols]

[0031] 10 Vehicle lighting fixture, 12 LED, 14 Substrate, 16 Plate-shaped light guide, 18 Reflector, 20 Extension, 22 Light-receiving portion, 24 Light-emitting portion, 26 Total reflection portion, 30 Incident portion, 32 First reflection portion, 34 Second reflection portion, 36 Third reflection portion, 38 Fourth reflection portion, 40 Cylindrical step.

Claims

1. A light source and a plate-shaped light guide including a light entrance portion that receives light from the light source and a light emitting portion that emits the light from the light entrance portion; Equipped with The light entrance section is an incident portion that allows light from the light source to enter the light incident portion; a first reflecting portion that radially reflects the light incident from the incident portion; a second reflecting section that reflects light reflected by the first reflecting section and traveling in a direction away from the light emitting section as parallel light; a third reflecting section that reflects the parallel light from the second reflecting section toward the light emitting section; A vehicle lamp comprising:

2. 2. The vehicular lamp according to claim 1, wherein the light incident portion further includes a fourth reflecting portion disposed between the second reflecting portion and the third reflecting portion, the fourth reflecting portion reflecting a portion of the parallel light from the second reflecting portion toward the light emitting portion.

3. 3. The vehicle lamp according to claim 2, wherein a height of the fourth reflecting portion is set smaller than a thickness of the light receiving portion.

4. 4. The vehicle lamp according to claim 1, wherein the first reflecting portion has a mortar-shaped reflecting surface.

5. 4. The vehicle lamp according to claim 1, wherein the second reflecting portion has a parabolic reflecting surface.

6. 4. The vehicle lamp according to claim 1, wherein the third reflecting portion has a multi-step reflecting surface in which a plurality of minute reflecting surfaces are connected in a stepped manner.

7. 4. The vehicle lamp according to claim 1, further comprising a total reflection portion between the light entrance portion and the light emitting portion, the total reflection portion reflecting light from the light entrance portion toward the light emitting portion.

8. 8. The vehicle lamp according to claim 7, wherein the total reflection portion is formed with a step for diffusing the total reflected light.

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