Vehicle lamp

Abstract

A vehicle lamp (1) comprises a light source (21) and a light-guide body (10) that is formed from a translucent material. The light-guide body (10) includes a plurality of first prism parts (16A) that reflect light from the light source (21) and an emission surface (11) that emits the light reflected by the plurality of first prism parts (16A). The plurality of first prism parts (16A) are arranged along a direction away from the light source (21). As seen from the emission direction of light from the emission surface (11), the light source (21) is separated from the plurality of first prism parts (16A) in a direction that intersects the arrangement direction of the plurality of first prism parts (16A). As seen from the emission direction, each of a plurality of first prism parts (16A) of the plurality of first prism parts (16A) that are provided in an area (30) that is close to the light source 21 at least extend in a direction that is orthogonal to a line (40) that passes through the location (22) of the light source (21).

Description

Vehicle lighting fixtures

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

[0002] Patent Document 1 discloses a vehicle lamp. The vehicle lamp in this document includes three or more light sources arranged along the longitudinal direction of the vehicle and a light guide that guides light from the three or more light sources and outputs it from each of the light output regions. That is, in the light guide of Patent Document 1, a light source is provided individually corresponding to each of a plurality of light output regions located at different positions.

[0003] Patent No. 6985806

[0004] Incidentally, a light guide of a vehicle lamp may be provided with a plurality of reflecting portions for the purpose of displaying a predetermined shape, etc. When a light source is provided for each reflecting portion, light of sufficient intensity is incident on and reflected from each reflecting portion, thereby obtaining sufficient brightness at each position on the light exit surface of the lamp. However, when the number of light sources provided is smaller than the number of reflecting portions, the relative positions of the light sources with respect to the reflecting portions are shifted, and light of sufficient intensity is not incident on some of the reflecting portions, which may result in an excessively uneven brightness distribution on the light exit surface.

[0005] An object of the present invention is to provide a vehicle lamp that can suppress a decrease in brightness on the light exit surface.

[0006] A vehicle lamp according to one aspect of the present invention includes a light source and a light guide formed of a translucent material. The light guide includes a plurality of first prism portions that reflect light from the light source and an exit surface that emits the light reflected by the plurality of first prism portions. The plurality of first prism portions are arranged in a direction away from the light source. When viewed from the direction in which the light is emitted from the exit surface, the light source is arranged apart from the plurality of first prism portions in a direction that intersects with the arrangement direction of the plurality of first prism portions. Of the plurality of first prism portions, each of the plurality of first prism portions provided in a region close to the light source extends at least in a direction perpendicular to a line passing through the position of the light source when viewed from the emission direction.

[0007] According to the present invention, it is possible to provide a vehicle lamp that can suppress a decrease in brightness on the light exit surface.

[0008] Fig. 1 is a perspective view of a vehicle lamp according to an embodiment. Fig. 2 is a front view of the vehicle lamp shown in Fig. 1. Fig. 3 is a diagram illustrating reflection of light by a first prism portion according to an embodiment. Fig. 4 is a diagram illustrating reflection of light by a second prism portion according to an embodiment.

[0009] A vehicle 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 vehicle longitudinal direction, respectively. LH and RH indicate the left and right in the vehicle width direction, respectively. UP and DN indicate the upper and lower in the vehicle vertical direction, respectively. In the following description, the front and rear in the vehicle longitudinal direction, the front and rear sides in the vehicle longitudinal direction, the left and right sides in the vehicle width direction, the left and right sides in the vehicle width direction, the upper and lower sides in the vehicle vertical direction, and the upper and lower sides in the vehicle vertical direction will be simply referred to as "front," "rear," "front side," "rear side," "left side," "right side," "left side," "right side," "upper," "lower," "upper side," and "lower side," respectively. Furthermore, in the following description, elements having the same functions will be designated by the same reference numerals, and redundant description will be omitted.

[0010] The vehicle lamp 1 according to this embodiment will be described using an example in which the vehicle lamp 1 is provided on each of the left and right sides of the rear of a vehicle body (not shown). Therefore, the rear side in the longitudinal direction of the vehicle is defined as the front side of the vehicle lamp 1, and the front side in the longitudinal direction of the vehicle is defined as the rear side of the vehicle lamp 1. The vehicle lamp 1 according to this embodiment operates as a functional lamp, such as a tail lamp, stop lamp, or rear turn signal lamp. Hereinafter, for convenience of explanation, the vehicle lamp 1 will be simply referred to as the lamp 1.

[0011] FIG. 1 is a perspective view of a lamp 1 mounted on the left rear side of a vehicle body (not shown). FIG. 2 is a front view of the lamp 1 shown in FIG. 1, viewed from the direction of light emission from the light exit surface 11 (see FIG. 1). FIG. 3 is a diagram showing light reflection by the first prism portion 16A in a cross section taken along the arrangement direction of the first prism portion 16A. FIG. 4 is a diagram showing light reflection by the second prism portion 16B in a cross section taken along the arrangement direction of the second prism portion 16B. Note that while FIG. 2 is a view of the lamp 1 as seen from the rear, for ease of explanation, the reflecting portion 15 located in front of the light exit surface 11 (see FIG. 3) is shown by a solid line. Also, the support portion 19 shown in FIG. 1 is omitted from FIGS. 3 and 4.

[0012] As shown in FIG. 1 , the lamp 1 includes a light guide 10. The light guide 10 is made of a translucent material such as PC (polycarbonate) or PMMA (acrylic). The light guide 10 shown in FIG. 1 has a predetermined thickness in the vehicle longitudinal direction and is formed in a plate shape extending in the vehicle width direction. Depending on the shape of the rear of the vehicle body, the light guide 10 may be partially or entirely curved in the vehicle longitudinal direction. Similarly, the light guide 10 may be partially or entirely curved in the vehicle height direction.

[0013] 1 to 4, the light guide 10 has an emission surface 11, a rear surface 12, and a side surface 13. The rear surface 12 is located forward of the emission surface 11 by the thickness of the light guide 10. The side surface 13 is also an incident surface for light from the light source 21. A reflecting portion 15 is formed on the rear surface 12. The reflecting portion 15 will be described in detail later.

[0014] As shown in Fig. 2, the lighting fixture 1 includes a light source unit 20. The light source unit 20 shown in Fig. 2 is located on the left side of the light guide 10. The light source unit 20 is provided so as to face the side surface 13 with a gap therebetween.

[0015] The light source unit 20 includes a light source 21 and a substrate 24 on which the light source 21 is attached. The light source 21 is, for example, a well-known LED module, and emits light from a light-emitting center 21a at a predetermined directivity angle θ. The light source 21 faces the side surface 13. An optical axis 23 of the light source 21 is, for example, perpendicular to the side surface 13. The directivity angle is, for example, an angle that is twice the light emission angle at which the light intensity is half that of the light intensity on the optical axis 23.

[0016] The light source unit 20 illustrated in Fig. 2 includes two light sources 21. The two light sources 21 are arranged at a distance from each other in the vertical direction of the vehicle. When viewed from the direction in which light is emitted from the emission surface 11, the first light source 21A is arranged at a distance from the plurality of first prism portions 16A in a direction intersecting the arrangement direction of the plurality of first prism portions 16A. When viewed from the direction in which light is emitted from the emission surface 11, the second light source 21B is arranged at a distance from the plurality of third prism portions 16C in a direction intersecting the arrangement direction of the plurality of third prism portions 16C.

[0017] Here, for convenience of explanation, the "light emission direction from the emission surface 11" will be simply referred to as the emission direction. When the lamp 1 is attached to the rear of the vehicle body, this emission direction is essentially the same as the rear in the fore-and-aft direction of the vehicle.

[0018] 3 and 4 , each light source 21 is disposed between the rear surface 12 and the light exit surface 11 in the longitudinal direction of the vehicle, at a position where the optical axis 23 does not interfere with the reflecting portion 15. The optical axis 23 is, for example, parallel to the rear surface 12. However, the position and direction of the optical axis 23 are arbitrary as long as there is no interference with the propagation of light along the vehicle width direction and the irradiation of light to each reflecting portion 15.

[0019] The substrate 24 is supported by columnar supports 19 that extend from the side surface 13 to the light source unit 20. This keeps the distance between each light source 21 and the side surface 13 constant, and also keeps the angle of the optical axis 23 relative to the side surface 13 constant.

[0020] Next, the reflecting portions 15 will be described. In this embodiment, four reflecting portions 15 are arranged at intervals in the vertical direction of the vehicle. For ease of explanation, these four reflecting portions 15 will be referred to, from top to bottom, as the second reflecting portion 15B, the first reflecting portion 15A, the fourth reflecting portion 15D, and the third reflecting portion 15C. Light from the first light source 21A is incident on the first reflecting portion 15A and the second reflecting portion 15B via the side surface 13. Light from the second light source 21B is incident on the third reflecting portion 15C and the fourth reflecting portion 15D via the side surface 13.

[0021] The first reflecting portion 15A has a plurality of first prism portions 16A. The plurality of first prism portions 16A are arranged along a first direction away from the first light source 21A. The first direction is, for example, the vehicle width direction. Each first prism portion 16A has a reflecting surface 17A that reflects light from the light source 21 toward the light output surface 11 (see FIG. 3 ).

[0022] As shown in FIG. 2 , among the plurality of first prism portions 16A, each of the plurality of first prism portions 16A provided in region 30 close to light source 21 extends at least in a direction perpendicular to line 40 passing through position 22 of light source 21 when viewed from the emission direction. This direction may be a tangential direction. For example, as shown in FIG. 2 , the plurality of first prism portions 16A provided in region 30 extend in an arc shape centered on light source 21 when viewed from the emission direction. Alternatively, the plurality of first prism portions 16A provided in region 30 may extend linearly in the perpendicular direction when viewed from the emission direction. Note that the "position of light source 21" specifically refers to the position of the light emission center, or, if light source 21 has an optical element, the position of the light convergence point.

[0023] A part of region 30 may overlap region 31 where, when viewed from the emission direction, the angle φ1 formed by the line 41 connecting each first prism portion 16A provided in region 30 to the position 22 of the light source 21 and the optical axis 23 of the light source 21 is greater than or equal to the directivity angle of the light source 21.

[0024] The second reflecting portion 15B has a plurality of second prism portions 16B. The plurality of second prism portions 16B are arranged along a second direction away from the light source 21 at a distance G from the arrangement of the plurality of first prism portions 16A. The second direction may be the vehicle width direction or another direction. In the former case, the distance G is constant. The arrangement of the plurality of second prism portions 16B is parallel to the arrangement of the plurality of first prism portions 16A.

[0025] Each second prism portion 16B has a reflecting surface 17B that reflects light from the first light source 21A toward the light exit surface 11 (see FIG. 4). Unlike the first prism portion 16A, the second prism portions 16B extend parallel to one another. Furthermore, when viewed from the light exit direction, the second prism portions 16B are positioned such that the angle φ2 formed between a line 42 connecting each second prism portion 16B to the position 22 of the light source 21 and the optical axis 23 of the light source 21 is equal to or smaller than the directivity angle θ of the light source 21. In other words, the second reflecting portion 15B is closer to the optical axis 23 than the first reflecting portion 15A.

[0026] The configuration of the third reflector 15C is the same as the configuration of the first reflector 15A. The configuration of the fourth reflector 15D is the same as the configuration of the second reflector 15B. The positional relationship of the third reflector 15C and the fourth reflector 15D with respect to the second light source 21B is the same as the positional relationship of the first reflector 15A and the second reflector 15B with respect to the first light source 21A. In other words, the light guide 10 of this embodiment is provided with two reflectors for one light source.

[0027] (1) The lighting fixture 1 according to this embodiment includes a light source 21, a plurality of first prism portions 16A that reflect light from the light source 21, and a light guide 10 made of a translucent material, the light guide 10 including an exit surface 11 that emits the light reflected by the plurality of first prism portions 16A. The plurality of first prism portions 16A are arranged in a direction away from the light source 21. When viewed from the direction of light emission from the exit surface 11, the light source 21 is spaced apart from the plurality of first prism portions 16A in a direction that intersects with the arrangement direction of the plurality of first prism portions 16A. Of the plurality of first prism portions 16A, each of the plurality of first prism portions 16A provided in a region 30 close to the light source 21 extends at least in a direction perpendicular to a line 40 that passes through the position 22 of the light source 21 when viewed from the light emission direction.

[0028] Light from the light source 21 entering the region 30 is emitted at a relatively large emission angle with respect to the optical axis 23. For example, if the first prism portions 16A in the region 30 extend in a direction perpendicular to the arrangement direction, the light would be incident on each first prism portion 16A at a large incidence angle, resulting in the light being reflected downward, for example. However, as described above, each of the multiple first prism portions 16A provided in the region 30 extends at least in a direction perpendicular to the line 40 passing through the position 22 of the light source 21, as viewed from the emission direction. Therefore, each first prism portion 16A in the region 30 can reflect light toward the emission surface 11. In other words, even if there is a relative positional misalignment with the light source 21, a decrease in brightness at the emission surface 11 can be suppressed, and the occurrence of localized dark areas on the emission surface 11 can be suppressed.

[0029] (2) The plurality of first prism portions 16A provided in region 30 may extend in an arc shape centered on position 22 of light source 21 when viewed from the emission direction. As described above, the intensity of light reaching region 30 may be significantly smaller than the intensity of light traveling on optical axis 23. However, by forming each first prism portion 16A in an arc shape, the area of ​​reflecting surface 17A that can reflect light to emission surface 11 can be increased. Therefore, a decrease in brightness at emission surface 11 can be suppressed.

[0030] (3) The plurality of first prism portions 16A provided in region 30 may extend linearly when viewed from the light output direction. This simplifies the design of each first prism portion 16A, thereby preventing costs from increasing. Furthermore, at least a portion of each first prism portion 16A has a reflective surface 17A that can reflect light toward the light output surface 11. This also prevents a decrease in brightness at the light output surface 11.

[0031] (4) The light guide 10 may include a plurality of second prism portions 16B that are arranged along a direction away from the light source 21 at intervals G from the arrangement of the plurality of first prism portions 16A and that reflect light from the light source 21 to the light output surface 11. In this case, the plurality of second prism portions 16B extend parallel to one another. Furthermore, the plurality of second prism portions 16B are located at positions where, when viewed from the light output direction, the angle formed by a line 42 connecting each second prism portion 16B to the position 22 of the light source 21 and the optical axis 23 of the light source 21 is equal to or smaller than the directivity angle of the light source 21.

[0032] The second prism portion 16B is located within a range defined by the directivity angle θ. Because the intensity of light within this range is sufficiently high, the light reflected by the second prism portion 16B also has sufficient intensity. Meanwhile, light from the same light source 21 is incident on the second prism portion 16B and the first prism portion 16A. In other words, while reducing the number of light sources 21, both prism portions can provide light emission at the exit surface 11 with reduced brightness reduction.

[0033] The above-described embodiments are merely examples described to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the above-described embodiments, but also includes various modifications, changes, alternative technologies, etc. that can be easily derived therefrom.

[0034] This application claims priority based on Japanese Application No. 2024-105051 filed on June 28, 2024, the entire contents of which are incorporated herein by reference.

[0035] REFERENCE SIGNS LIST 1 vehicular lamp 10 light guide 11 emission surface 12 back surface 13 side surface 21 light source 22 (light source) position 15 reflecting portion 15A first reflecting portion 15B second reflecting portion 16A first prism portion 16B second prism portion 30 area 40 line

Claims

1. A vehicle lamp comprising: a light source; and a light guide formed of a translucent material, including a plurality of first prism portions that reflect light from the light source, and an exit surface that emits the light reflected by the plurality of first prism portions; wherein the plurality of first prism portions are arranged in a direction away from the light source; the light source is arranged at a distance from the plurality of first prism portions in a direction that intersects with the arrangement direction of the plurality of first prism portions, as viewed from the direction in which the light is emitted from the exit surface; and each of the plurality of first prism portions that are provided in an area close to the light source extends at least in a direction perpendicular to a line passing through the position of the light source, as viewed from the emission direction.

2. The vehicle lamp according to claim 1, wherein the plurality of first prism portions provided in the region extend in an arc shape centered on the position of the light source when viewed from the emission direction.

3. The vehicular lamp according to claim 1, wherein the plurality of first prism portions provided in the region extend linearly when viewed from the light output direction.

4. A vehicular lamp according to any one of claims 1 to 3, wherein the light guide includes a plurality of second prism portions that are arranged along a direction away from the light source at intervals from the arrangement of the plurality of first prism portions and that reflect the light from the light source to the emission surface, the plurality of second prism portions extending parallel to one another, and the plurality of second prism portions are located at positions where, when viewed from the emission direction, the angle formed by a line connecting each of the second prism portions to the position of the light source and the optical axis of the light source is equal to or less than the beam angle of the light source.

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