Vehicle lamp

Abstract

This vehicle lamp includes: a light source; and a first light guide rod and a second light guide rod that emit light by light from the light source. The second light guide rod includes: a main body part on which light from the light source is incident; and an incident part that causes light propagated through the main body part to be incident on the first light guide rod from a side surface of the first light guide rod. A first uneven structure for causing light from the light source to be emitted from a side surface of the main body part is provided on a surface of the main body part. The width of the incident part decreases as being separated from the main body part. A second uneven structure finer than the first uneven structure is provided on a surface of the incident part.

Description

Vehicle lighting fixtures

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

[0002] Patent Document 1 discloses a structure of a vehicle lamp in which a plurality of LED light sources and a plurality of light guides of different lengths are arranged, and the light guides are provided with an incident portion, a reflecting portion, and an exit surface.

[0003] Patent No. 6985806

[0004] When light propagating through one light guide rod is incident on the other light guide rod, changing the shape or arrangement of one light guide rod partially can cause the forward emitted light to be locally intensified, which can result in uneven forward emitted light in the vicinity of that portion.

[0005] The object of the present invention is to provide a vehicle lighting fixture that prevents the light emitted forward from becoming locally stronger and becoming uneven when light propagating through one light guide rod is incident on the other light guide rod.

[0006] A vehicle lamp according to one aspect of the present invention comprises a light source, and a first light guiding rod and a second light guiding rod that emit light using light from the light source. The second light guiding rod is composed of a main body portion into which light from the light source is incident, and an incident portion that causes light that has propagated through the main body portion to be incident on the first light guiding rod from the side of the first light guiding rod. The surface of the main body portion is provided with a first uneven structure for causing light from the light source to exit from the side of the main body portion, the width of the incident portion decreases with increasing distance from the main body portion, and the surface of the incident portion is provided with a second uneven structure that is finer than the first uneven structure.

[0007] According to the present invention, when light propagating through one light guide rod is incident on the other light guide rod, it is possible to prevent the light emitted forward from becoming locally stronger and the light emitted forward from becoming uneven.

[0008] FIG. 1 is an exploded perspective view of a headlamp unit including a vehicle lamp according to an embodiment. FIG. 2 is a front view showing the structure of the vehicle lamp. FIG. 3 is a perspective view showing the structure of a light source unit. FIG. 4 is a schematic diagram showing the structure of a first light guiding rod and a second light guiding rod. FIG. 5A is a cross-sectional view taken along line A-A in FIG. 4. FIG. 5B is a cross-sectional view taken along line B-B in FIG. 4. FIG. 5C is a cross-sectional view taken along line C-C in FIG. 4. FIG. 6 is an enlarged view of a main portion of FIG. 4. FIG. 7 is an enlarged view of the incident portion of the second light guiding rod.

[0009] A vehicular lamp 1 according to an embodiment will now be described with reference to the drawings. In each drawing, FR and RR indicate the front and rear in the longitudinal direction of the vehicle, respectively, UP and DN indicate the upper and lower in the vertical direction of the vehicle, and LH and RH indicate the left and right in the width direction of the vehicle. In the following description, the front and rear in the longitudinal direction of the vehicle, the upper and lower in the vertical direction of the vehicle, and the left and right in the width direction of the vehicle will be simply referred to as the front, rear, upper, lower, left, and right, respectively. Furthermore, components having the same functions as those already described will be denoted by the same reference numerals and will not be described again. Below, a vehicular lamp 1 disposed on the left side of the front of the vehicle will be described as an example. A vehicular lamp 1 disposed on the right side of the front of the vehicle will be similar, and therefore will not be described again. Furthermore, the vehicular lamp 1 may be disposed on the left or right side of the rear of the vehicle.

[0010] The vehicle lamp 1 includes a light source 2, and a first light guide rod 11 and a second light guide rod 21 that are light guides that emit light using light from the light source 2 (see FIG. 2).

[0011] As shown in Fig. 1, the vehicle lamp 1 is one of the components of a vehicle headlamp unit L. When installed on a vehicle, the vehicle lamp 1 extends, for example, in a substantially horizontal direction while curving in the longitudinal direction of the vehicle. The vehicle lamp 1 may be mounted to a housing of the headlamp unit L together with a lens, etc. The headlamp unit L is disposed, for example, on the inner side of the front end of the fender panel in the vehicle width direction and above the end of the front bumper.

[0012] 2 and 3, the vehicle lamp 1 includes a light source unit (hereinafter referred to as the light source unit 2) as a light source 2. The light source unit 2 is disposed at the outer end of the vehicle lamp 1 in the vehicle width direction, and includes a circuit board and LED light sources 2A and 2B mounted on the circuit board.

[0013] As illustrated in FIG. 3 , the LED light sources 2A and 2B are arranged adjacent to each other in the vertical direction. The LED 2A is arranged close to the outer end of the first light guiding rod 11 in the vehicle width direction and emits light toward the end of the first light guiding rod 11. This allows the light emitted from the LED 2A to enter the first light guiding rod 11. Similarly, the LED 2B is arranged close to the outer end of the second light guiding rod 21 in the vehicle width direction and emits light toward the end of the second light guiding rod 21. This allows the light emitted from the LED 2A to enter the second light guiding rod 21. Note that the configuration of the light source unit 2 is not limited to the above. The light source unit 2 may include a control unit that controls the turning on and off of the LED light sources 2A and 2B. Alternatively, a single LED light source may be used, and the light emitted from the single LED light source may be incident on the first light guiding rod 11 and the second light guiding rod 21.

[0014] 2 , the first light guiding rod 11 extends forward from its outer end in the vehicle width direction and then curves inward in the vehicle width direction. The first light guiding rod 11 has, for example, a substantially circular cross-sectional shape. Light emitted from the LED 2A and incident on the end of the first light guiding rod 11 is reflected by the inner surface in the radial direction of the first light guiding rod 11 and then propagates to the other end in the longitudinal direction of the first light guiding rod 11 (the inner end in the vehicle width direction).

[0015] As illustrated in FIGS. 4-6 , the surface of the first light guiding rod 11 may be provided with an uneven structure P3 for causing a portion of the light emitted from the LED 2A to exit from the side surface of the first light guiding rod 11. For example, the uneven structure P3 is provided on the surface on the back side (rear side) of the first light guiding rod 11. As a result, a portion of the light emitted from the LED 2A is emitted forward from the side surface of the first light guiding rod 11. The uneven structure P3 may be formed over the entire length of the first light guiding rod 11. In this case, the uneven structure P3 causes the first light guiding rod 11 to emit light over the entire length of the first light guiding rod 11. Details of the uneven structure P3 will be described later.

[0016] As illustrated in Figure 2-6, the second light guiding rod 21 is disposed adjacent to and below the first light guiding rod 11 and extends along the first light guiding rod 11. The second light guiding rod 21 extends forward from the outer end in the vehicle width direction, then curves inward in the vehicle width direction and extends to near the center of the first light guiding rod 11. The second light guiding rod 21 has, for example, a substantially circular cross-sectional shape. The second light guiding rod 21 includes a main body portion 22 into which light from the light source unit 2 is incident, and an incident portion 23 that causes light propagated through the main body portion 22 to enter the first light guiding rod 11 (see Figures 2 and 4).

[0017] Light emitted from LED 2B and incident on the end of the main body 22 is reflected by the inner surface of the main body 22 in the radial direction and propagates to the other end of the main body 22 in the longitudinal direction (the end on the inner side in the vehicle width direction). As illustrated in Figures 4-6, a first uneven structure P1 is provided on the surface of the main body 22 to allow a portion of the light emitted from LED 2B to exit from the side of the main body 22. For example, the first uneven structure P1 is provided on the surface on the back side (rear side) of the main body 22. As a result, a portion of the light emitted from LED 2B is emitted forward from the side of the main body 22. The first uneven structure P1 may be formed over the entire length of the main body 22. In this case, the first uneven structure P1 causes the main body 22 to emit light over the entire length of the main body 22.

[0018] The first uneven structure P1 is, for example, a prism in which recesses, protrusions, flat portions, etc. formed with predetermined unevenness dimensions and width dimensions are arranged in the radial and longitudinal directions of the main body 22. A portion of the light propagating inside the second light guiding rod 21 is reflected by a prism formed at a predetermined position of the second light guiding rod 21 (in this embodiment, on the surface on the rear side of the second light guiding rod 21) and emitted in a predetermined direction (forward in this embodiment). Note that the unevenness dimensions and the arrangement pattern of the uneven structure may change in a gradational manner or the like depending on the position of the second light guiding rod 21. The uneven structure P3 of the first light guiding rod 11 may be configured similarly to the first uneven structure P1.

[0019] The incident portion 23 is formed in the longitudinal direction of the second light guiding rod 21, toward the tip end, which is inward in the vehicle width direction from the main body portion 22 (see FIGS. 2 and 4). The width S of the incident portion 23 is formed to become smaller toward the tip 23A of the incident portion 23 (see FIGS. 4, 6, and 7). That is, the second light guiding rod 21 gradually decreases in diameter toward the tip 23A. Furthermore, the tip 23A is positioned close to and along the side surface of the first light guiding rod 11. At this time, the tip 23A is positioned so that the side surface of the incident portion 23 is at a predetermined angle or less with respect to the side surface of the first light guiding rod 11 (see FIG. 6). This allows the incident portion 23 to efficiently direct light propagating through the main body portion 22 into the first light guiding rod 11. In other words, when light that has propagated through the main body 22 is merged from the incident portion 23 into the first light guide rod 11, by giving the incident portion 23 the above-mentioned shape and arrangement, it is possible to prevent some of the light from leaking out to the outside without being merged from the incident portion 23 into the first light guide rod 11.

[0020] When light propagating through the main body 22 is converged from the incident portion 23 to the first light guiding rod 11, the forward emitted light may be locally intensified due to the shape and arrangement of the incident portion 23, etc. This may result in uneven forward emitted light at the end of the main body 22 and near the incident portion 23. Therefore, a second uneven structure P2, which is finer than the first uneven structure P1, is provided on the surface of the incident portion 23 (see Figures 4, 6, and 7). As a result, a portion of the light emitted forward from the first uneven structure P1 is scattered by the second uneven structure P2, thereby attenuating the forward emitted light at the incident portion 23. For example, the unevenness dimensions and width dimensions of the second uneven structure P2 may be smaller than those of the first uneven structure P1. Furthermore, the arrangement pattern of the uneven structure of the second uneven structure P2 may be shorter than that of the first uneven structure P1. Furthermore, the second uneven structure P2 may be composed of periodically or randomly arranged dot-shaped concave or convex portions.

[0021] 5A-5C illustrate cross-sectional shapes at various locations of the vehicle lamp 1. The cross-sectional direction in each figure is perpendicular to the longitudinal direction of the vehicle lamp 1 (the width direction of the first light guide rod 11 and the second light guide rod 21) and does not necessarily coincide with the longitudinal direction of the vehicle. As illustrated in FIG. 5A, in the left portion (the outer portion in the vehicle width direction) of the vehicle lamp 1, the main body portions 22 of the first light guide rod 11 and the second light guide rod 21 are arranged adjacent to each other in the vertical direction. The rear surface of the first light guide rod 11 is provided with an uneven structure P3. The rear surface of the main body portion 22 is provided with a first uneven structure P1. As illustrated in FIG. 5B, in the central portion of the vehicle lamp 1 in the vehicle width direction, the incident portions 23 of the first light guide rod 11 and the second light guide rod 21 are arranged adjacent to each other in the vertical direction. The outer diameter of the incident portion 23 is smaller than that of the main body portion 22. An uneven structure P3 is provided on the surface on the rear side of the first light guiding rod 11. A second uneven structure P2 is provided on the surface on the front side of the incident portion 23. As illustrated in Fig. 5C, in the right part of the vehicle lamp 1 (the inner part in the vehicle width direction), the second light guiding rod 21 does not extend to that position, and only the first light guiding rod 11 is provided. An uneven structure P3 is provided on the surface on the rear side of the first light guiding rod 11.

[0022] As illustrated in FIG. 7 , the unevenness dimensions of the first uneven structure P1 may be formed to become smaller toward the tip 23A of the incident portion 23. Furthermore, the width dimension of the first uneven structure P1, the arrangement pattern of the uneven structure, etc. may change toward the tip 23A of the incident portion 23. Furthermore, in a front view, at least a portion of the second uneven structure P2 may be arranged to overlap the first uneven structure P1 (see FIG. 7 ). In other words, in a front view, the tip edge P1A of the first uneven structure P1 may be located to the left of the rear end edge P2A of the second uneven structure P2, and on the inside in the vehicle width direction. That is, the second uneven structure P2 may be formed spanning from the incident portion 23 to a portion of the main body portion 22.

[0023] (1) A vehicle lamp 1 according to an embodiment includes a light source unit 2 serving as a light source, and a first light guide rod 11 and a second light guide rod 21 that emit light using light from the light source unit 2. The second light guide rod 21 is composed of a main body 22 into which light from the light source 2 is incident, and an incident portion 23 through which light propagating through the main body 22 is incident into the first light guide rod 11 from a side surface of the first light guide rod 11. The surface of the main body 22 is provided with a first uneven structure P1 for causing light from the light source unit 2 to exit from the side surface of the main body 22. The width of the incident portion 23 decreases with increasing distance from the main body 22, and the surface of the incident portion 23 is provided with a second uneven structure P2 that is finer than the first uneven structure P1. As a result, a portion of the light emitted forward from the first uneven structure P1 is scattered by the second uneven structure P2, thereby attenuating the forward-emitting light at the incident portion 23 and preventing the forward-emitting light from becoming locally intense. Therefore, it is possible to prevent the forward emitted light from becoming non-uniform near the incident portion 23 .

[0024] (2) In the embodiment, the unevenness dimensions of the first uneven structure P1 are formed to become smaller toward the tip 23A of the incident portion 23. This allows the intensity of light emitted forward from the first uneven structure P1 to be gradually reduced at the incident portion 23. Therefore, it is possible to further prevent the forward emitted light from becoming non-uniform near the incident portion 23.

[0025] (3) Furthermore, in the embodiment, at least a portion of the second concave-convex structure P2 is arranged to overlap with the first concave-convex structure P1 in a front view. That is, in a front view, the leading edge P1A of the first concave-convex structure P1 is located more inward in the vehicle width direction than the trailing edge P2A of the second concave-convex structure P2. This allows a portion of the light emitted forward from the first concave-convex structure P1 to be attenuated by the second concave-convex structure P2, thereby more gradually suppressing the intensity of the light emitted forward. This further suppresses unevenness in the light emitted forward near the incident portion 23.

[0026] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0027] This application claims priority to Japanese Application No. 2024-105553, filed on June 28, 2024, the entire contents of which are incorporated herein by reference.

[0028] REFERENCE SIGNS LIST 1 Vehicle lamp 2 Light source unit (light source) 11 First light guide rod 21 Second light guide rod 22 Main body 23 Incident portion 23A Tip P1 First concave-convex structure P2 Second concave-convex structure S Width

Claims

1. A vehicle lamp comprising: a light source; and a first light guiding rod and a second light guiding rod that emit light using light from the light source, wherein the second light guiding rod is composed of a main body portion into which light from the light source is incident, and an incident portion that causes light that has propagated through the main body portion to be incident into the first light guiding rod from a side surface of the first light guiding rod, wherein the surface of the main body portion is provided with a first uneven structure for causing light from the light source to exit from the side surface of the main body portion, the width of the incident portion decreases with increasing distance from the main body portion, and wherein the surface of the incident portion is provided with a second uneven structure that is finer than the first uneven structure.

2. The vehicle lamp according to claim 1, wherein the first uneven structure is formed so that the uneven dimensions become smaller toward the tip of the incident portion.

3. The vehicular lamp according to claim 2, wherein at least a portion of the second uneven structure is arranged to overlap with the first uneven structure in a front view.

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