Vehicle lamp

Abstract

To provide a vehicle lamp with improved light utilization efficiency.SOLUTION: A vehicle lamp 10 comprises: a first LED 28 and a second LED 30; and a light guide body 32 including an incident part 34 that receives light from the first LED 28 and the second LED 30, a light guide part 38 that guides the light incident from the incident part 34, and an emission part 40 that emits the light guided through the light guide part 38. A light diffusion part 42 is provided in a portion of the light guide part 38 that receives direct light from the first LED 28 and the second LED 30, for diffusing the direct light and making it incident into the light guide part 38.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Conventionally, there have been proposed vehicle lamps that combine a light source such as an LED with a 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 an entrance portion of the light guide, travels through the light guide, and is emitted forward of the lamp from an exit portion of the light guide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-67521 [Patent Document 2] Patent Publication No. 2021-190342 [Patent Document 3] Patent Publication No. 2021-51950 Summary of the Invention [Problem to be solved by the invention]

[0004] A problem with a vehicle lamp having the above-described configuration is that the light emitted from the light source that does not enter the entrance portion is not effectively utilized.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a vehicle lamp with improved light utilization efficiency. [Means for solving the problem]

[0006] In order to solve the above problems, a vehicle lamp according to one aspect of the present invention includes a light source, a light guide including an incident portion for receiving light from the light source, a light guide portion for guiding the light incident from the incident portion, and an exit portion for emitting the light guided through the light guide portion, and a light diffusion portion is provided in a portion of the light guide portion that receives direct light from the light source, the light diffusion portion being configured to diffuse the direct light and cause it to enter the light guide portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a vehicle lamp with improved light utilization efficiency. [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] FIG. 10 is a front perspective view of the third lamp unit. [Figure 3] FIG. 10 is a rear perspective view of the third lamp unit. [Figure 4] FIG. 4 is a schematic vertical cross-sectional view of a third lamp unit. [Figure 5] FIG. 10 is a diagram showing the results of a ray tracing simulation when the first LED is made to emit light. [Figure 6] FIG. 10 is a diagram showing the results of a ray tracing simulation when the second LED is made to emit light. [Figure 7] FIG. 10 is a diagram showing the results of a ray tracing simulation performed as a comparative example when an LED placed in front of the first LED in the lamp is made to emit light. 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. As shown in Fig. 1, the vehicle lamp 10 includes a lamp body 12 and a transparent outer cover 14 that covers the front opening of the lamp body 12. The lamp body 12 and the outer cover 14 form a lamp chamber 16.

[0011] The vehicle lamp 10 according to this embodiment is a combination headlamp, and has one first lamp unit 18, one second lamp unit 20, and four third lamp units 22 arranged in a lamp chamber 16. The four third lamp units 22 are arranged side by side in a direction inclined relative to the vehicle width direction, following the shapes of the lamp body 12 and the outer cover 14. The number of each lamp unit is not particularly limited.

[0012] The first lamp unit 18 functions as a high and low beam lamp, the second lamp unit 20 functions as a daytime running lamp and a clearance lamp, and the third lamp unit 22 functions as a turn signal lamp and a clearance lamp.

[0013] The structure of the first lamp unit 18 that functions as a high and low beam lamp is not particularly limited, and for example, a reflector type or projector type lamp unit can be used. The structure of the second lamp unit that functions as a daytime running lamp and clearance lamp is also not particularly limited, and for example, a lamp unit that uses a light source such as an LED and a light guide can be used.

[0014] Fig. 2 is a front perspective view of the third lamp unit 22. Fig. 3 is a rear perspective view of the third lamp unit 22. Fig. 4 is a schematic vertical cross-sectional view of the third lamp unit 22. The following mainly describes the configuration of one third lamp unit 22, but the other third lamp units 22 have the same configuration.

[0015] 2 to 4, the third lamp unit 22 includes a bracket 24, a substrate 26 provided on the bracket 24, a first LED 28 and a second LED 30 as light sources mounted on the substrate 26, and a light guide 32 that controls the light from the first LED 28 and the second LED 30 and irradiates it forward of the lamp. The light guide 32 is supported on the substrate 26. The third lamp unit 22 is fixed to the lamp body 12 via the bracket 24.

[0016] The first LED 28 and the second LED 30 have different light emission colors. The first LED 28 is used as a light source for a turn signal lamp and emits amber light. The second LED 30 is used as a light source for a clearance lamp and emits white light. The first LED 28 and the second LED 30 emit light when supplied with current from the substrate 26. The first LED 28 and the second LED 30 are arranged on the substrate 26 so that their respective optical axes Ax1 and Ax2 face upward.

[0017] In this embodiment, the light guide 32 has a generally plate-like shape extending in the longitudinal direction of the vehicle. The light guide 32 is disposed above the first LED 28 and the second LED 30 such that its extension direction is perpendicular to the optical axes Ax and Ax2. The light guide 32 has a lower surface 32a facing the first LED 28 and the second LED 30, an upper surface 32b opposite the lower surface 32a, a front end surface 32c facing forward from the lamp, and a rear end surface 32d facing rearward from the lamp. The light guide 32 is formed from a transparent resin material such as acrylic or polycarbonate.

[0018] The light guide 32 includes an incident portion 34 onto which light from the first LED 28 and the second LED 30 is incident, a reflecting portion 36 that totally reflects the light that has entered the light guide 32 from the incident portion 34, a light guide portion 38 that guides the light totally reflected by the reflecting portion 36, and an exit portion 40 that emits the light guided through the light guide portion 38.

[0019] The incident portion 34 is provided on the rear side of the lower surface 32a of the light guide 32. The incident portion 34 has a focal point F and has a lens shape that converts light from a light source disposed at the focal point F into parallel light. As shown in FIG. 4, the first LED 28 is disposed at the focal point F. The second LED 30 is disposed further rearward of the lamp than the first LED 28 (at a position farther from the emission portion 40 than the first LED 28).

[0020] The reflecting portion 36 is provided on the rear end surface 32d of the light guide 32. The reflecting portion 36 is inclined with respect to the optical axis Ax1 so that light incident on the light guide 32 from a light source disposed at the focal point F of the incident portion 34 is totally reflected. As shown in FIG. 3, the reflecting portion 36 may be formed with cylindrical steps that diffuse the reflected light.

[0021] Light-guiding section 38 has a generally plate shape and guides the light that has been totally reflected by reflecting section 36. Exit section 40 is provided at the front end (front end surface 32c) of light-guiding section 38. As shown in FIG. 2, exit section 40 may be provided with multiple fisheye lenses. Exit section 40 emits the light that has been guided through light-guiding section 38 forward of the lamp.

[0022] In the third lamp unit 22 according to this embodiment, a light diffusion portion 42 is provided near the incident portion 34 on the lower surface 32a of the light guide 32. The light diffusion portion 42 is provided in a portion of the light guide 38 that receives direct light from the first LED 28 and the second LED 30.

[0023] The light diffusion section 42 is configured to diffuse direct light from the first LED 28 and the second LED 30 and cause the light to enter the light guide section 38. The light diffusion section 42 may be formed by roughening the lower surface 32a of the light guide 32. The roughening may be achieved by forming minute concaves and convexes on the lower surface 32a of the light guide 32. The light diffusion section 42 may be formed by textured the lower surface 32a of the light guide 32.

[0024] 4, the light L1 emitted from the first LED 28 in a direction of approximately 45 degrees is represented by a dashed line. This light L1 is the light emitted from the first LED 28 that does not enter the incident portion 34. The light L1 enters the light diffusion portion 42 as direct light. "Direct light" means light that arrives directly from the light source without being reflected from other components.

[0025] Light L1 incident on the light diffusion portion 42 is diffused by the light diffusion portion 42 when it enters the light guide portion 38. In FIG. 4, light L2 diffused by the light diffusion portion 42 is represented by a thick dashed line. As shown in FIG. 4, light L2 is repeatedly reflected by the lower surface 32a and the upper surface 32b of the light guide 32, and then emitted to the outside of the light guide 32. Note that although light L2 is shown as being emitted from the emission portion 40 in FIG. 4, it may also be emitted from the lower surface 32a or the upper surface 32b. Furthermore, although the light emitted from the first LED 28 has been described above, the same applies to light emitted from the second LED 30.

[0026] Thus, according to the third lighting unit 22 of this embodiment, the light emitted from the first LED 28 and the second LED 30 that does not enter the incident portion 34 can be emitted from the light guide 32, thereby increasing the total amount of light emitted from the third lighting unit 22 and improving the light utilization efficiency.

[0027] Even when the light guide 38 does not include the light diffusion section 42, light still enters the light guide 38 from the lower surface 32a and can be emitted from the light guide 38. However, in this case, because the light diffusion section 42 does not diffuse the light, a phenomenon in which a portion of the light guide 32 shines brighter than other areas can occur. If this locally bright light is projected onto, for example, an extension member inside the lamp chamber 16, so-called "point light" can occur, in which an image of the light source is reflected on the extension member. According to the third lamp unit 22 of this embodiment, the light diffusion section 42 diffuses direct light, thereby suppressing the phenomenon in which a portion of the light guide 32 shines brightly. Therefore, according to the third lamp unit 22 of this embodiment, it is possible to improve light utilization efficiency while suppressing point light.

[0028] 4, a light diffusion portion 44 may be provided on the upper surface 32b of the light guide 32. Direct light from the first LED 28 and the second LED 30 is not incident on the lower surface 32a of the light guide 32, but some of the light incident from the incident portion 34 may enter and cause spot light. By providing a light diffusion portion 44 on the upper surface 32b of the light guide 32 as well, spot light can be suppressed.

[0029] FIG. 5 shows the results of a ray tracing simulation when the first LED 28 is illuminated. As described above, the first LED 28 is a light source located at the focal point F of the incident portion 34. As shown in FIG. 5, the light emitted from the first LED 28 is collimated at the incident portion 34 and enters the light guide 32. The collimated light entering the light guide 32 is totally reflected by the reflecting portion 36 and directed toward the front of the lamp, travels through the light guide 38, and is emitted from the exit portion 40. As described above, the first LED 28 is used as a light source for a turn signal lamp. For turn signal lamps with relatively strict light distribution requirements, a desired light distribution pattern can be achieved by locating a light source at the focal point of the first LED 28.

[0030] FIG. 6 shows the results of a ray tracing simulation when the second LED 30 is illuminated. As described above, the second LED 30 is used as a light source for a clearance lamp. The second LED 30 is arranged rearward of the lamp relative to the first LED 28. The third lamp unit 22 according to this embodiment is used for both a turn signal lamp and a clearance lamp. Because the first LED 28 for the turn signal lamp is arranged at the focal point F of the incident portion 34, the second LED 30 cannot be arranged at the focal point F of the incident portion 34, and must be arranged rearward of the first LED 28 or forward of the first LED 28.

[0031] 6, when the second LED 30 is disposed behind the first LED 28 in the lamp, the angle of incidence of the light from the second LED 30 on the reflecting portion 36 is larger than the angle of incidence of the light from the first LED 28 on the reflecting portion 36. As described above, the reflecting portion 36 is configured to totally reflect the light from the first LED 28, so that the light from the second LED 30, which has a larger angle of incidence than the light from the first LED 28, can also be totally reflected and directed toward the front of the lamp, and emitted from the emitting portion 40.

[0032] As a comparative example, Fig. 7 shows the results of a ray tracing simulation in which an LED 46 disposed further forward than the first LED 28 in the lamp is illuminated. In this case, the angle of incidence of light from the LED 46 on the reflecting portion 36 may be smaller than the angle of incidence of light from the first LED 28 on the reflecting portion 36. Therefore, some of the light from the LED 46 may have an angle of incidence below the critical angle and pass through the reflecting portion 36 without being totally reflected, as shown in Fig. 7. In this case, less light is emitted forward from the emitting portion 40, which may reduce the amount of light emitted by the clearance lamp.

[0033] As can be seen from the results of the ray tracing simulations in Figures 6 and 7, according to the third lighting unit 22 of this embodiment, the efficiency of use of light emitted from the second LED 30 can be improved by positioning the second LED 30 further rearward of the lighting fixture than the first LED 28.

[0034] 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]

[0035] 12 Lamp body, 14 Outer cover, 16 Lamp chamber, 18 First lamp unit, 20 Second lamp unit, 22 Third lamp unit, 24 Bracket, 26 Board, 28 First LED, 30 Second LED, 32 Light guide, 34 Incident portion, 36 Reflecting portion, 38 Light guide portion, 40 Exit portion, 42, 44 Light diffusion portion.

Claims

1. A light source and a light guide including an incident portion to which light from the light source is incident, a light guide portion to guide the light incident from the incident portion, and an exit portion to emit the light guided through the light guide portion; Equipped with A vehicle lamp comprising: a light diffusing section provided at a portion of the light guide section that receives direct light from the light source, the light diffusing section diffusing the direct light and causing the direct light to enter the inside of the light guide section.

2. 2. The vehicle lamp according to claim 1, wherein the light diffusing portion is subjected to a roughening treatment.

3. 2. The vehicle lamp according to claim 1, wherein the light diffusion portion is textured.

4. the incident portion includes a lens shape that converts light from a light source disposed at a focal point into parallel light, the light guide includes a reflecting portion that totally reflects the light incident from the incident portion toward the light guide portion, the light source includes a first light source and a second light source; the first light source is disposed at the focal point; The second light source is disposed rearward of the lamp relative to the first light source.

2. A vehicle lamp according to claim 1.

5. the first light source is a light source for a turn signal lamp, The second light source is a light source for a clearance lamp.

5. A vehicle lamp according to claim 4.

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