JP2015022993A - Vehicle headlamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for actualizing the entry of more light fluxes from a light source into a slender lens.SOLUTION: A vehicular headlight 100 includes a projection lens 10 having an entrance surface 10a and an emission surface 10b which are slender with their vehicle width directions as longitudinal directions, and having an optical axis Ax extending in a vehicle longitudinal direction X, a light source 12 arranged on the further rearward side than a rear side focus F of the projection lens 10, and a reflector 14 for reflecting at least part of light emitted from the light source 12 toward the projection lens 10. The light source 12 is arranged so that the front side of a light-emitting surface 12a faces the lateral side of the reflector 14.

Description

  The present invention relates to a vehicle headlamp.

  Conventionally, light emitted from a light emitting element such as a light emitting diode is incident on a horizontally long light guide plate along a horizontal plane from its rear end surface, and then emitted from its front end surface toward the front of the lamp. A vehicular lamp is known (see, for example, Patent Document 1).

JP 2013-26008 A

  In recent years, various attempts have been made to create new designs for vehicle headlamps. Among them, a vehicular headlamp has been devised that uses an elongated lens in front view instead of a conventional circular lens.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique for causing a light beam of a light source to be incident on a long and narrow lens more.

  In order to solve the above-described problems, a vehicle headlamp according to an aspect of the present invention includes a projection having an elongated entrance surface and an exit surface with the vehicle width direction as a longitudinal direction and an optical axis extending in the vehicle longitudinal direction. A lens; a light source disposed behind the rear focal point of the projection lens; and a reflector that reflects at least part of the light emitted from the light source toward the projection lens. The light source is arranged so that the front surface of the light emitting surface faces the side of the reflector.

  Of the light emitted from the light source, most of the light that is reflected by the reflector above the light source and travels downward does not enter the projection lens having an elongated incident surface with the vehicle width direction as the longitudinal direction. Therefore, there is room for further improvement from the viewpoint of capturing the light flux in the projection lens. According to this aspect, the light emitted from the front surface of the light emitting surface of the light source is directed to the side of the reflector (vehicle width direction) and reflected by the reflector to the opposite side (vehicle width direction). Generally, a light source has a large amount of light flux in the front direction of its light emitting surface. Therefore, a large amount of light that is emitted from the front direction of the light emitting surface and reflected in the vehicle width direction rather than in the vertical direction of the vehicle is incident on an elongated incident surface having the vehicle width direction as a longitudinal direction.

  The light source may have a horizontally long light emitting surface, and the light emitting surface may be arranged such that the longitudinal direction of the light emitting surface is along the vehicle front-rear direction. Since the light source is arranged so that the front of the light emitting surface faces the side of the reflector, when the light emitted from the horizontally long light emitting surface is reflected by the reflector, it becomes a shape that spreads in the vehicle width direction, and more light flux Is incident on the projection lens.

  The reflector has an elliptical reflecting surface, and is arranged so that the first focal point on the front side is in the vicinity of the rear focal point of the projection lens, and the major axis of the elliptical reflecting surface is in the vehicle width direction with respect to the optical axis. It may be arranged so as to be inclined. The light source is disposed in the vicinity of the second focal point on the rear side of the elliptical reflecting surface, and the light emitting surface is disposed so as to face the elliptical reflecting surface of the reflector on the opposite side across the optical axis. Good. Thereby, the entire surface of the projection lens can be effectively used, and the utilization factor of the light beam can be increased.

  You may further provide the condensing member provided between a light source and a reflector, and condenses the light radiate | emitted from the light source toward the reflective surface of a reflector. Thereby, it is suppressed that the light radiate | emitted from the light source diverges to a perpendicular direction, and it can condense efficiently toward the side of a reflector.

  The light source may be arranged such that the front surface of the light emitting surface faces in the horizontal direction. Thereby, more light flux of the light source can be incident on the elongated lens.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to make more light flux of a light source incident on an elongated lens.

1A is a perspective view of an elongated projection lens according to the present embodiment, FIG. 1B is a side view of the projection lens viewed from the direction A shown in FIG. 1A, and FIG. ) Is a front view of the projection lens viewed from the B direction shown in FIG. It is a schematic diagram which shows schematic structure of the vehicle headlamp which concerns on a comparative example. It is a perspective view which shows schematic structure of the vehicle headlamp which concerns on 1st Embodiment. It is a schematic diagram which shows schematic structure of the vehicle headlamp which concerns on 1st Embodiment. It is a schematic diagram which shows schematic structure of the vehicle headlamp which concerns on 2nd Embodiment. 6A is a diagram showing a front view of the light source shifted upward from the focal position of the reflector, FIG. 6B is a diagram showing a light distribution pattern of the configuration shown in FIG. 6 (c) is a diagram showing a front view in a state where the light source is shifted downward from the focal position of the reflector, and FIG. 6 (d) is a diagram showing a light distribution pattern in the case of FIG. 6 (c). It is a schematic diagram which shows schematic structure of the front view of the vehicle headlamp which concerns on 4th Embodiment. It is a perspective view of the vehicle headlamp which concerns on 5th Embodiment. It is a schematic diagram which shows schematic structure of the front view of the vehicle headlamp which concerns on 6th Embodiment. FIG. 10A to FIG. 10C are diagrams showing light distribution patterns formed by the lamp units shown in FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Further, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(First embodiment)
First, an elongated projection lens will be described. 1A is a perspective view of an elongated projection lens according to the present embodiment, FIG. 1B is a side view of the projection lens viewed from the direction A shown in FIG. 1A, and FIG. ) Is a front view of the projection lens viewed from the B direction shown in FIG.

  The projection lens 10 shown in FIG. 1A to FIG. 1C has a shape that is rounded with the central portion of a spherical or aspherical convex lens or plano-convex lens remaining, and the vehicle width direction Y is the longitudinal direction. And an optical axis Ax extending in the longitudinal direction X of the vehicle. Below, the case where such a projection lens 10 is applied to a vehicle headlamp will be described.

  FIG. 2 is a schematic diagram showing a schematic configuration of a vehicle headlamp 200 according to a comparative example. The vehicle headlamp 200 includes a projection lens 10, a light source 12, a reflector 14, and a shade 16. The reflector 14 has an elliptical reflecting surface 14a and a mounting portion 14b on which the light source 12 is mounted. The shade 16 is disposed so that the tip thereof is positioned in the vicinity of the first focal point F <b> 1 on the front side of the reflector 14. The light source 12 is disposed in the vicinity of the second focal point F <b> 2 on the rear side of the reflector 14. Note that the projection lens 10 is disposed such that the rear focal point F substantially coincides with the first focal point F1 of the reflector 14.

  The light source 12 shown in FIG. 2 is arranged so that the front surface of the light emitting surface 12a faces the reflector 14. In this case, of the light emitted from the light source 12 (L1, L2, L3), most of the light reflected by the reflector 14 above the light source 12 and traveling downward (for example, L2, L3) extends in the vehicle width direction. The light does not enter the projection lens 10 having the elongated incident surface 10a in the direction. That is, only the light L1 emitted backward from the light emitting surface 12a of the light source 12 and having a small reflection angle enters the projection lens 10. Therefore, there is room for further improvement from the viewpoint of capturing the light flux in the projection lens 10.

  Therefore, as a result of intensive studies by the present inventors, the inventors have come up with the idea that more light flux from the light source can be incident on the elongated lens by adopting the following configuration. FIG. 3 is a perspective view showing a schematic configuration of the vehicle headlamp 100 according to the first embodiment. FIG. 4 is a schematic diagram showing a schematic configuration of the vehicle headlamp 100 according to the first embodiment. In FIG. 4, the shade is not shown.

  The vehicle headlamp 100 is directed to the projection lens 10, the light source 12 disposed behind the rear focus F of the projection lens 10, and at least part of the light emitted from the light source 12 toward the projection lens 10. And a reflector 14 that reflects the light. The light source 12 is disposed so that the front surface of the light emitting surface 12 a faces the side of the reflector 14.

  Thereby, the light emitted from the front surface of the light emitting surface 12a of the light source 12 is directed to the side of the reflector 14 (vehicle width direction Y) and is reflected by the reflector 14 to the opposite side (vehicle width direction Y). Generally, the light source 12 has a large amount of light flux in the front direction of the light emitting surface 12a. In particular, when the light source 12 is a semiconductor light emitting element (for example, an LED element, an LD element, an EL element, etc.), the tendency is remarkable. Here, the front surface of the light emitting surface 12a can be referred to as a direction perpendicular to the light emitting surface 12a or the brightest direction.

  The light source 12 shown in FIGS. 3 and 4 is arranged so that the front surface of the light emitting surface 12a faces the side of the reflector 14. In this case, the light emitted from the front direction of the light emitting surface 12a and reflected by the reflector 14 in the vehicle width direction Y, not in the vehicle vertical direction Z (see FIG. 3), is elongated with the vehicle width direction Y as the longitudinal direction. More incident light is incident on the incident surface 10a. That is, as shown in FIG. 4, not only light L1 ′ having a small reflection angle emitted from the light emitting surface 12a of the light source 12 but also light emitted from the light emitting surface 12a directly or diagonally forward and having a large reflection angle. L2 ′ and L3 ′ are also incident on the projection lens 10. Thus, the vehicular headlamp 100 is configured to cause more light flux of the light source 12 to enter the projection lens 10.

  The light source 12 according to the present embodiment is arranged so that the front surface of the light emitting surface 12a faces in the horizontal direction (the longitudinal direction of the incident surface 10a of the projection lens 10). As a result, more light flux from the light source 12 can be incident on the elongated projection lens 10.

  As described above, the light source 12 is preferably arranged so that the front surface of the light emitting surface 12a is right side (horizontal direction), but is not necessarily limited thereto. For example, the light source 12 may be arranged such that the front surface of the light emitting surface 12a is 60 ° or less, preferably 45 ° or less, more preferably 30 ° or less from the horizontal direction.

  Further, as shown in FIG. 3, the light source 12 according to the present embodiment forms a horizontally long light emitting surface 12a by arranging a plurality of semiconductor light emitting elements. Moreover, it arrange | positions so that the longitudinal direction of the light emission surface 12a may follow the vehicle front-back direction X. FIG. Since the light source 12 is arranged so that the front surface of the light emitting surface 12a faces the side of the reflector 14, when the light emitted from the horizontally long light emitting surface 12a is reflected by the reflector, the light source 12 has a shape spreading in the vehicle width direction Y. , More light flux enters the projection lens 10.

(Second Embodiment)
FIG. 5 is a schematic diagram showing a schematic configuration of the vehicle headlamp 110 according to the second embodiment. In FIG. 5, the shade is not shown.

  As described above, the reflector 14 has the elliptical reflecting surface 14 a and is arranged so that the first focal point F <b> 1 on the front side is in the vicinity of the rear focal point F of the projection lens 10. Further, the long axis AL of the elliptical reflecting surface 14a is disposed so as to be inclined in the vehicle width direction Y with respect to the optical axis Ax. The light source 12 is disposed in the vicinity of the second focal point F2 on the rear side of the elliptical reflecting surface 14a, and the light emitting surface 12a is one side of the elliptical reflecting surface 14a of the reflector on the opposite side across the optical axis Ax. It arrange | positions so that a part may be opposed. Thereby, it is possible to increase the light incident on the vicinity of the optical axis Ax of the projection lens 10.

  Further, since the light reflected by the reflector 14 disposed obliquely enters the entire surface of the projection lens 10, the utilization factor of the light flux can be increased.

(Third embodiment)
In the third embodiment, a light distribution pattern of a vehicle headlamp when the light source is shifted from the focal position of the reflector will be described. 6A is a diagram showing a front view of the light source shifted upward from the focal position of the reflector, FIG. 6B is a diagram showing a light distribution pattern of the configuration shown in FIG. 6 (c) is a diagram showing a front view in a state where the light source is shifted downward from the focal position of the reflector, and FIG. 6 (d) is a diagram showing a light distribution pattern in the case of FIG. 6 (c). In FIG. 6A and FIG. 6C, the projection lens is not shown.

  The light source 12 shown in FIG. 6A is disposed at a position shifted from the second focal point F2 of the elliptical reflecting surface 14a of the reflector 14. Thereby, a low beam light distribution pattern PL as shown in FIG. 6B is formed. The light source 12 shown in FIG. 6C is disposed at a position shifted downward from the second focal point F2 of the elliptical reflecting surface 14a of the reflector 14. As a result, a low beam light distribution pattern PL as shown in FIG. 6D is formed. Thus, by shifting the position of the light source 12 from the focal point, the irradiation range of the low beam light distribution pattern PL can be changed.

(Fourth embodiment)
FIG. 7 is a schematic diagram showing a schematic configuration of a vehicle headlamp according to a fourth embodiment in a front view. In FIG. 7, the projection lens is not shown. In the vehicle headlamp 120, a light collecting member 18 is provided between the light source 12 and the reflector 14. The condensing member 18 condenses the light emitted from the light emitting surface 12 a of the light source 12 toward the elliptical reflecting surface 14 a of the reflector 14. The condensing member 18 is constituted by, for example, a reflector or a light guide member. Thereby, it is suppressed that the light radiate | emitted from the light source 12 diverges in the orthogonal | vertical direction, and it concentrates efficiently toward the side of the reflector 14 which is an effective reflective surface area | region for formation of a light distribution pattern.

(Fifth embodiment)
FIG. 8 is a perspective view of a vehicle headlamp according to a fifth embodiment. The vehicle headlamp 130 according to the fifth embodiment includes a beam shaper 20 whose upper surface is a reflective surface, instead of the shade 16 in the vehicle headlamp 100 according to the first embodiment. The feature is that it has.

  The beam shaper 20 includes a fan-shaped shade body 20a that forms a cut line of the low-beam light distribution pattern PL, and a reflective upper surface 20b that extends from the upper end of the shade body 20a toward the rear of the lamp. Have. The reflective upper surface 20b has a reflective surface formed of a metal member or a metal film. Thereby, part of the light (light L ′) emitted from the light source 12 and reflected by the reflector 14 is reflected by the reflection upper surface 20 b of the beam shaper 20 and enters the incident surface 10 a of the elongated projection lens 10. Therefore, in the vehicular headlamp 130, the light that has been shielded by the shade body 20 a can be incident on the projection lens 10 unless the reflective upper surface 20 b is provided.

(Sixth embodiment)
FIG. 9 is a schematic diagram showing a schematic configuration of a vehicle headlamp according to a sixth embodiment when viewed from the front. In FIG. 9, the projection lens is not shown. The vehicle headlight 140 forms a predetermined light distribution pattern by combining a plurality of projector optical systems. The vehicle headlamp 140 has three lamp units 142, 144, 146. The lamp unit 142 has the same configuration as the vehicle headlamp 100 described above. In addition, the lamp units 144 and 146 irradiate a predetermined range by reflecting light emitted upward from the light source 150 forward by the reflector 152 and shielding part of the light by the shade 154.

  FIG. 10A to FIG. 10C are diagrams showing light distribution patterns formed by the lamp units shown in FIG. A light distribution pattern PL1 shown in FIG. 10A is a light distribution pattern for condensing. FIG. 10B is a diagram showing a light distribution pattern for medium diffusion. FIG. 10C is a diagram showing a light distribution pattern for large diffusion. By combining a plurality of light distribution patterns formed by the three lamp units 142, 144, and 146, the vehicle headlamp 140 can achieve a wider range of irradiation while increasing the brightness near the center of the front.

  As described above, the present invention has been described with reference to the above-described embodiment. However, the present invention is not limited to the above-described embodiment, and the present invention can be appropriately combined or replaced with the configuration of the embodiment. It is included in the present invention. In addition, it is possible to appropriately change the combination and processing order in the embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to the embodiment. The described embodiments can also be included in the scope of the present invention.

  The vehicle headlamps according to the above-described embodiments have been described as forming a low-beam light distribution pattern, but the present invention can be applied even if a high-beam light distribution pattern is formed. Further, the vehicle headlamp may be a fog lamp, a day running lamp, or the like. Further, the incident surface and the exit surface of the projection lens may be configured by free-form surfaces.

  F1 first focus, F2 second focus, 10 projection lens, 10a entrance surface, 10b exit surface, 12 light source, 12a light emission surface, 14 reflector, 14a elliptical reflection surface, 14b mounting portion, 16 shade, 18 light collecting member, 20 beam shaper, 20a shade body, 20b reflective upper surface, 100 vehicle headlamp.

Claims (5)

A projection lens having an elongated entrance surface and an exit surface with the vehicle width direction as the longitudinal direction, and an optical axis extending in the vehicle front-rear direction;
A light source disposed behind the rear focal point of the projection lens;
A reflector that reflects at least part of the light emitted from the light source so as to be directed toward the projection lens;
The vehicle light source, wherein the light source is disposed such that a front surface of the light emitting surface faces a side of the reflector.   The vehicle headlamp according to claim 1, wherein the light source has a horizontally long light emitting surface, and is arranged so that a longitudinal direction of the light emitting surface is along a vehicle front-rear direction. The reflector has an elliptical reflecting surface, and is arranged such that the first focal point on the front side is in the vicinity of the rear focal point of the projection lens, and the major axis of the elliptical reflecting surface is relative to the optical axis. It is arranged to be diagonal in the vehicle width direction,
The light source is disposed in the vicinity of the second focal point on the rear side of the elliptical reflecting surface, and is disposed so that the light emitting surface faces the elliptical reflecting surface of the reflector on the opposite side across the optical axis. Being
The vehicle headlamp according to claim 1 or 2, characterized in that   4. The light emitting device according to claim 1, further comprising a light collecting member that is provided between the light source and the reflector and collects light emitted from the light source toward a reflection surface of the reflector. The vehicle headlamp described in the paragraph.   5. The vehicle headlamp according to claim 1, wherein the light source is disposed such that a front surface of the light emitting surface faces in a horizontal direction. 6.

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