JP2014167879A - Vehicular lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lighting fixture using a light guide body which forms no dark region and can emit light uniformly.SOLUTION: A vehicular lighting fixture 10 includes a light source 21 and a light guide body 30 which transmits light from the light source 21. The light guide body 30 includes: a first incident surface 31a arranged at a position facing the light emitting surface of the light source 21; a pair of second incident surfaces 31b which are arranged to face each other with the first incident surface 31a therebetween and on which the light from the light source 21 is incident; a pair of reflection surfaces 32 which are provided outside the second incident surfaces 31b as viewed from the first incident surface 31a and on which the light from the light source 21 is internally reflected; an emission surface 33 from which the light from the light source 21 is emitted; and a refraction part 34 which is provided between the second incident surfaces 31b and the emission surface 33 and refracts light L1 which is at least part of light incident on the first incident surface 31a so that the light L1 is close to parallel with light L2 reflected by the reflection surfaces 32 toward the emission surface 33.

Description

  The present invention relates to a vehicular lamp.

  Conventionally, a refractive reflection part for refracting light emitted from the light emitting element and entering the inner lens is formed on the back surface of the inner lens, and the light from the light emitting element is emitted from the front surface of the inner lens to the front of the lamp. A vehicular lamp is known (see Patent Document 1).

Japanese Patent Laid-Open No. 62-229701

  In the vehicular lamp as disclosed in Patent Document 1, an inclined surface is provided in the refractive reflection portion of the inner lens by a draft angle of the mold for easily releasing the injection molded inner lens. Due to the influence of the surface, a dark part with a small amount of light is formed in the irradiation area in front of the lamp.

  Therefore, an object of the present invention is to provide a vehicular lamp using a light guide that can emit light uniformly without forming a dark part.

In order to achieve the above object, a vehicular lamp according to the present invention comprises:
A light source;
A light guide through which light from the light source is transmitted;
With
The light guide is
A first incident surface disposed at a position facing the light emitting surface of the light source;
A pair of second incident surfaces disposed opposite to each other across the first incident surface, on which light from the light source is incident;
A pair of reflecting surfaces provided on the outer side of the second incident surface as viewed from the first incident surface and from which the light from the light source is internally reflected;
An exit surface from which light from the light source is emitted;
Provided between each second entrance surface and the exit surface, at least a part of the light incident on the first entrance surface is parallel to the light reflected from the respective reflective surfaces toward the exit surface. A refracting part that refracts so that
It is characterized by having.

  In the vehicular lamp of the present invention, the refracting portion may be configured by a boundary surface between a cavity portion disposed inside the light guide and the light guide.

  In the vehicular lamp according to the present invention, the light guide may be formed as a single molded product in which a plurality of adjacent light guides are integrated.

  In the vehicular lamp of the present invention, the width of the refracting portion may be larger than the width of the first incident surface in a direction perpendicular to an axis extending in the vehicle front-rear direction through the center of the light source.

In the vehicle lamp of the present invention, the vehicle lamp has a pair of positioning surfaces provided between each of the pair of second incident surfaces and each of the pair of reflection surfaces,
The width of the refracting portion may be substantially the same as the maximum distance between the pair of positioning surfaces in a direction orthogonal to an axis extending in the vehicle front-rear direction through the center of the light source.

  According to the present invention, the light guide body refracts at least a part of the light incident on the first incident surface so as to be parallel to the light reflected from the pair of reflecting surfaces toward the exit surface. Therefore, even if the incident surface of the light guide has an inclination due to the draft angle, the light guide can be caused to emit light uniformly without forming a dark portion through which light does not pass. it can.

It is a cross-sectional view which shows the structure of the vehicle lamp which concerns on the 1st Embodiment of this invention. It is a partially expanded view of the vehicular lamp shown in FIG. FIG. 3 is a partially enlarged view of the light source and the light guide shown in FIG. 2. It is a block diagram of the light source and light guide which concern on the modification of 1st Embodiment. It is a block diagram of the light source and light guide which concern on another modification of 1st Embodiment. It is AA sectional drawing of the structure shown by FIG. It is a block diagram of the light source and light guide which concern on a prior art example.

  Hereinafter, an example of an embodiment of a vehicular lamp according to the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, a vehicular lamp 10 according to a first embodiment of the present invention includes a resin lamp body 11 that is fixed to a vehicle body in a shape in which the front side of the lamp (right side in FIG. 1) is opened. And an outer cover 12 made of transparent resin attached to the opening of the lamp body 11. The outer cover 12 is disposed so as to close the opening of the lamp body 11 from the front, and forms a lamp chamber S between the outer cover 12 and the lamp body 11. The vehicular lamp 10 is used as a vehicular tail lamp, for example.

  The vehicular lamp 10 includes a lamp unit 20 in a lamp chamber S formed by a lamp body 11 and an outer cover 12. An extension 50 is provided in the lamp chamber S to cover the gap between the lamp body 11 and the lamp unit 20 when viewed from the outer cover 12 side. The lamp unit 20 is fixed to a flexible printed circuit board (hereinafter referred to as FPC) 51, and the FPC 51 is attached to a resin base 53 via a heat dissipation plate 52. The lamp unit 20 includes a plurality of light sources 21 and a plurality of light guides 30.

  Each of the plurality of light sources 21 is composed of a white light emitting diode (LED) having a light emitting portion having a size of about 1 mm square, for example. As shown in FIG. 2, these light sources 21 emit light substantially uniformly in the vertical and horizontal directions from the light emission surface 21a toward the front of the lamp. The light source 21 is mounted on the FPC 51 so that the surface 21 b opposite to the light emitting surface 21 a faces the FPC 51. On the back side of the FPC 51, a plurality of aluminum heat sinks 52 for dissipating heat generated from the light sources 21 and the FPC 51 are arranged.

  A plurality of light guides 30 are formed as a single molded product 40 that is integrated adjacently, and extends in the left-right direction when viewed from the rear of the vehicle. As shown in FIG. 2, each light guide 30 includes an incident surface 31, a pair of reflecting surfaces 32, an exit surface 33, a refracting portion 34, and a positioning surface 36. Further, the light guides 30 at both ends are each provided with a protruding portion 30a, and the protruding portion 30a is assembled on the back side of the extension 50 in a front view of the lamp.

  The incident surface 31 is disposed at a position facing the light emitting surface 21a of each light source 21, and is opposed to each other with the first incident surface 31a on which light from each light source 21 is incident and the first incident surface 31a interposed therebetween. And a pair of second incident surfaces 31b on which light from each light source 21 is incident.

  The first incident surface 31a is configured by a surface that is concavely curved with respect to the light source 21 when viewed from above, and is a surface on which light L1 incident from the light source 21 is incident on a refracting portion 34 described later.

  The second incident surface 31b is configured by an inclined surface that is slightly convexly curved with respect to the light source 21 in a top view. This inclined surface is a draft required when the light guide 30 is molded from the mold after being molded. The second incident surface 31 b is a surface on which at least a part of the light L 2 out of the light incident from the light source 21 to the second incident surface 31 b is incident toward the reflecting surface 32.

  The pair of reflecting surfaces 32 are provided on the outer side of each second incident surface 31b when viewed from the first incident surface 31a, and are surfaces on which light from the light source 21 is internally reflected. Each reflection surface 32 is formed such that the shape in plan view of FIG. 2 is a curve that reflects incident light L2 as parallel light, such as a parabolic curve or an elliptic curve. Each reflecting surface 32 is arranged in a direction parallel to an axis (hereinafter referred to as an optical axis) Ax in which the reflected light L2 passes through the center of the light source 21 and extends in the vehicle front-rear direction. Therefore, the light L2 incident from each second incident surface 31b and internally reflected by each reflecting surface 32 becomes light substantially parallel to the optical axis Ax, and is guided in the light guide 30 toward the front of the lamp. Is done.

  The emission surface 33 is formed in a curved shape such as an arc along the shape of the outer cover 12, and has a plurality of minute curved convex steps. Lights L1 and L2 guided in the light guide 30 are irradiated from the emission surface 33 toward the front of the lamp.

The refracting portion 34 is provided between the incident surface 31 and the emitting surface 33, and is configured by a boundary surface between the hollow portion 35 disposed inside the light guide 30 and the light guide 30. As shown in FIG. 2, the refracting portion 34 includes a refracting surface 34 a that is a boundary surface between the cavity portion 35 and the light guide 30 and that faces the first incident surface 31 a, and the boundary surface that is the output surface 33. And a refracting surface 34b facing each other. The refractive surface 34 a is a curved surface that is substantially concave with respect to the light source 21, and the refractive surface 34 b is a curved surface that is substantially convex with respect to the light source 21. Through the two refracting surfaces 34a and 34b, at least a part of the light L1 incident on the first incident surface 31a is reflected by the light L2 reflected from the reflecting surfaces 32 toward the emitting surface 33. It is refracted so as to be parallel to it.
Further, in the direction orthogonal to the optical axis Ax, the width W1 of the refracting portion 34 is formed to be larger than the maximum interval W2 between the second incident surfaces 31b.

  As shown in FIG. 3, in the refracting portion 34, a corner portion 34 </ b> A called a displacement point is provided at the end of the refracting surface 34 a on the side facing the incident surface 31. Since the corner portion 34A has to be rounded for convenience of molding, part of the light incident from the incident surface 31 is diffused by the corner portion 34A, and light unevenness is likely to occur. However, in this example, the refracting surface 34a, which is a surface connecting the corner portions 34A of the refracting portion 34, is curved in a substantially concave shape with respect to the light source 21, so that the light L3 diffused by the corner portion 34A is refracted. The light is reflected by the surface 34a and guided to the reflective surface 32 on the opposite side. According to this, the light L3 passing through the displacement point 34A, which is likely to be light unevenness, is guided to the reflection surface 32 on the opposite side, and is internally reflected toward the emission surface 33 side by the reflection surface 32, thereby generating light unevenness. Can be prevented.

  The positioning surface 36 is a planar surface provided between each second incident surface 31 b and each reflecting surface 32. The pair of positioning surfaces 36 are surfaces for preventing the light guide 30 from cracking when the molded light guide 30 is pulled out of the mold, and guides the light to the FPC 51 on which the light source 21 is mounted. It is a surface for positioning when the body 30 is fixed. As shown in FIG. 2, in the direction orthogonal to the optical axis Ax, the maximum interval W3 between the pair of positioning surfaces 36 is formed to be substantially the same as the width W1 of the refracting portion 34. If the maximum distance W3 is too small than the width W1 of the refracting portion 34, it is difficult to remove the light guide 30 from the mold after molding. On the other hand, if the maximum interval W3 is too larger than the width W1 of the refracting portion 34, a dark portion may be formed in the light guide 30 due to the influence of the positioning surface 36.

  FIG. 7 is a top view showing a light source 21 and a light guide 130 according to a conventional example. As shown in FIG. 7, the light guide 130 includes a first incident surface 131 a, a second incident surface 131 b, a reflecting surface 132, an exit surface 133, and between the second incident surface 131 b and the reflecting surface 132. The surface 136 is provided. The light emitted from the light source 21 and incident on the boundary between the first incident surface 131a and the second incident surface 131b is refracted at the boundary and becomes light substantially parallel to the optical axis Ax, and is guided toward the output surface 133. The The light emitted from the light source 21 and incident on the boundary between the surface 136 and the reflecting surface 132 is refracted at the boundary and becomes light substantially parallel to the optical axis Ax, and is guided toward the emission surface 133. The light emitted from the light source 21 and incident on the second incident surface 131b is internally reflected by the reflecting surface 132, becomes light substantially parallel to the optical axis Ax, and is guided toward the emitting surface 133. Thus, in the conventional light guide 130 in which the refracting portion 34 is not provided, the second incident surface 131b and the second incident surface 131b provided with an inclination due to the draft are provided between the reflecting surface 132 and the second incident surface 131b. Due to the influence of the surface 136, a dark portion D with a small amount of light is formed in the light guide 130 between the second incident surface 131 b and the emission surface 133, and it is difficult to obtain uniform light emission.

  On the other hand, according to the vehicle lamp 10 of the present embodiment, as shown in FIG. 2, the light guide 30 reflects at least a portion of the light L1 incident on the first incident surface 31a as a pair of reflections. A refracting section 34 is provided that refracts light so as to be parallel to the light L2 reflected from the surface 32 toward the exit surface 33. Therefore, even if the incident surface 31 (second incident surface 31b) of the light guide 30 is provided with an inclination due to the draft, no dark portion is formed in the light guide 30, and the light guide 30 emits light uniformly. Can be made.

  Further, according to the present embodiment, the refracting portion 34 is configured by a boundary surface between the cavity portion 35 disposed inside the light guide 30 and the light guide 30. Therefore, it is possible to prevent the occurrence of a dark portion with a simple configuration in which the hollow portion 35 is simply provided inside the light guide 30.

  Further, according to the present embodiment, the light guide 30 is formed as a single molded product 40 that is adjacently integrated. Therefore, by appropriately increasing or decreasing the number of the light guides 30, it can be applied to the vehicle lamp 10 having various shapes while maintaining uniform light emission.

  Further, according to the present embodiment, the width W1 of the refracting portion 34 is formed larger than the maximum interval W2 of the second incident surface 31b in the direction orthogonal to the optical axis Ax. For this reason, it is possible to more reliably prevent the occurrence of a dark portion due to the inclination of the second incident surface 31b.

  Furthermore, according to this embodiment, a pair of positioning surfaces 36 are provided between each second incident surface 31b and each reflecting surface 32, and the width W1 of the refracting portion 34 is a pair in the direction orthogonal to the optical axis Ax. This is substantially the same as the maximum interval W3 between the positioning surfaces 36. Therefore, it is possible to appropriately prevent the dark portion from being formed by the positioning surface 36 while ensuring the workability of removing the light guide 30 from the mold.

  In the first embodiment, the refracting portion 34 is formed from a single cavity 35, but, as in the modification shown in FIG. 4, two cavities 35A are provided inside the light guide 30D. May be provided, and the refracting part 34 may be formed from the boundary surface between each cavity 35A and the light guide 30D. Since each cavity 35A is provided between each second incident surface 31b and the emission surface 33, the formation of a dark portion can be prevented and uniform light emission can be realized as in the first embodiment.

(Second Embodiment)
Next, a lamp unit 20A according to a second embodiment of the present invention will be described with reference to FIG. The description of elements having the same or similar configuration and function as the lamp unit 20 in the first embodiment is omitted.

  As shown in FIG. 5, in the lamp unit 20 </ b> A, an inner lens 60 is provided between the light source 21 and the incident surface 31 of the light guide 30. The inner lens 60 is made of, for example, glass or resin. The inner lens 60 is formed by integrally molding a plurality of lenses in accordance with the shape of the light guides 30 adjacent to each other. The surface of the inner lens 60 facing the light source 21 is formed in an arc shape in a cross section perpendicular to the vertical direction in FIG. 6 and in a straight line shape (that is, a cylindrical surface) in a cross section perpendicular to the horizontal direction in FIGS. ing. Further, the surface of the inner lens 60 facing the incident surface 31 has an arc shape in a cross section perpendicular to the vertical direction in FIG. 6 and an arc shape in a cross section perpendicular to the horizontal direction in FIGS. 5 and 6 (that is, a toroidal surface). Is formed.

  As shown in FIG. 6, the light L <b> 4 emitted from the optical axis Ax of the light source 21 and emitted in the front-rear direction passes through the inner lens 60 and is refracted and condensed in the front-rear direction to enter the incident surface 31. Is done. That is, the inner lens 60 approaches the light L4 in a direction parallel to the optical axis Ax in a direction (vertical direction in FIG. 6) orthogonal to the plane including the light source 21 and the incident surface 31 and the reflection surface 32 of the light guide 30. So that it can be condensed.

  According to the lamp unit 20A of the present embodiment described above, the light L4 in the vertical direction that cannot be incident on the incident surface 31 in the first embodiment among the light emitted from the light source 21 is also caused by the inner lens 60. The light can be condensed in the vertical direction and incident on the incident surface 31. Therefore, the utilization efficiency of light from the light source 21 can be further increased.

  In the above, the example of embodiment of this invention was demonstrated, However, This invention is not limited to the said embodiment, It is possible to employ | adopt another structure as needed.

  In the above embodiment, the refracting portion 34 is formed by providing the hollow portion 35 inside the light guide 30. However, the present invention is not limited to this example. For example, by sealing a resin material having a refractive index different from that of the light guide inside the light guide, the refracting portion is formed from the boundary surface between the light guide and the resin material having a different refractive index provided therein. It may be formed.

  In the above embodiment, the light exit surface 33 of the light guide 30 is formed to have an arc shape when viewed from above according to the shape of the outer cover 12. However, any shape such as a linear shape or a bent shape may be used. It may be.

  In the above embodiment, the positioning surface 36 is a flat surface, but may be any shape such as a curved surface or a stepped surface as long as it can be fixed to the FPC 51.

  In addition, the vehicular lamp 10 can be used not only as a tail lamp, but also as other vehicular lamps such as a headlamp and a turn signal lamp, if necessary.

  10: vehicle lamp, 11: lamp body, 12: outer cover, S: lamp chamber, 20: lamp unit, 21: light source, 30: light guide, 31a: first incident surface, 31b: second incident surface, 32: Reflective surface, 33: Output surface, 34: Refraction part, 35: Cavity part, 36: Positioning surface, 40: Single molded product, 50: Extension, 51: Flexible printed circuit board (FPC), 52: Heat sink 53: Resin base, 60: Inner lens

Claims (5)

A light source;
A light guide through which light from the light source is transmitted;
With
The light guide is
A first incident surface disposed at a position facing the light emitting surface of the light source;
A pair of second incident surfaces disposed opposite to each other across the first incident surface, on which light from the light source is incident;
A pair of reflecting surfaces provided on the outer side of the second incident surface as viewed from the first incident surface and from which the light from the light source is internally reflected;
An exit surface from which light from the light source is emitted;
Provided between each second entrance surface and the exit surface, at least a part of the light incident on the first entrance surface is parallel to the light reflected from the respective reflective surfaces toward the exit surface. A refracting part that refracts so that
A vehicular lamp characterized by comprising:   2. The vehicular lamp according to claim 1, wherein the refracting portion is configured by a boundary surface between a hollow portion disposed inside the light guide and the light guide.   The vehicular lamp according to claim 1, wherein the light guide is formed as a single molded product in which a plurality of adjacent light guides are integrated.   The width of the refracting portion is larger than the width of the second incident surface in a direction orthogonal to an axis extending in the vehicle longitudinal direction through the center of the light source. The vehicle lamp as described. A pair of positioning surfaces provided between each of the pair of second incident surfaces and each of the pair of reflection surfaces;
5. The width of the refracting portion is substantially the same as the maximum distance between the pair of positioning surfaces in a direction orthogonal to an axis extending in the vehicle longitudinal direction through the center of the light source. The vehicular lamp according to claim 1.

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