JP2009230903A - Headlamp for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a headlamp for a vehicle in which illuminance of a prescribed portion in a light distribution pattern can be selectively raised with a simple structure. <P>SOLUTION: The headlamp for the vehicle 10 includes a main reflector 15 to reflect light from a light source 11a, a projection lens to irradiate light to the front, a shade 13 to shield part of reflection light going from the main reflector 15 to the projection lens 12, a first sub reflector 17 of substantially elliptical spherical shape which is arranged between the main reflector 15 and the projection lens 12, and a second sub reflector 18 which is arranged in the vicinity of a second focus F5 of the first sub reflector 17 and reflects light toward the shade 13. The second sub reflector 18 is integrally installed on the projection lens 12 side of the shade 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle headlamp.

  Conventionally, as a vehicle headlamp, a main reflector that reflects light from a light source, a projection lens that is disposed in front of the main reflector, and a rear part of the projection lens that partially shields reflected light from the main reflector The thing provided with the shade to perform is known (for example, refer to patent documents 1).

In this Patent Document 1, the upper end of the projection lens and the upper end of the main reflector are arranged so that the first sub-reflector having a substantially elliptic spherical shape has the light source as one focus and the other focus between the projection lens and the main reflector. And the lower end of the projection lens so that the second sub-reflector having a substantially elliptical shape has the other focal point in the vicinity of the light source, with the other focal point of the first sub-reflector as one focal point. Placed between the lower end of the main reflector and illuminates the light incident on the first sub-reflector from the light source forward via the second sub-reflector and the main reflector, thereby selecting the illuminance at a predetermined location in the light distribution pattern Is increasing.
JP 2006-59555 A

  However, in this conventional technique, in order to selectively increase the illuminance at a predetermined location in the light distribution pattern, it is necessary to arrange the first and second sub-reflectors so that the respective focal points are at the above positions. At times, high accuracy is required, and productivity is poor.

  Accordingly, an object of the present invention is to obtain a vehicle headlamp that can selectively increase the illuminance at a predetermined location in a light distribution pattern with a simpler structure.

  The invention according to claim 1 is a light source, a main reflector that reflects light from the light source, a projection lens that irradiates reflected light from the main reflector forward, and an edge that forms a cut-off line in a light distribution pattern A shade that blocks a part of reflected light from the main reflector toward the projection lens, a first focal point in the vicinity of the light source, and a second focal point closer to the projection lens than the shade. The first sub-reflector having a substantially elliptical spherical shape disposed between the main reflector and the projection lens, and disposed in the vicinity of the second focal point of the first sub-reflector, is reflected by the first sub-reflector. A second sub-reflector that reflects reflected light toward the shade, and the second sub-reflector is disposed on the projection lens side of the shade. Characterized in that provided in the body manner.

  According to a second aspect of the present invention, in the vehicle headlamp according to the first aspect, the second sub-reflector reflects the reflected light reflected by the first sub-reflector toward the edge portion of the shade. It is characterized by.

  A third aspect of the present invention is the vehicle headlamp according to the first or second aspect, wherein the first sub-reflector is formed integrally with a frame that supports the projection lens. To do.

  According to the first aspect of the present invention, the second sub-reflector that is disposed in the vicinity of the second focal point of the first sub-reflector and reflects the reflected light reflected by the first sub-reflector toward the shade is provided on the shade. Since it is provided on the projection lens side, the light emitted from the light source toward the first sub-reflector is reflected from the first sub-reflector toward the second sub-reflector, reflected from the second sub-reflector toward the shade, and shaded. It can reflect toward the projection lens located ahead from. In this way, the light irradiated from the light source toward the first sub-reflector is reflected forward through the first sub-reflector, the second sub-reflector and the shade, and is irradiated forward through the projection lens. Thus, the illuminance at a predetermined location of the light distribution pattern can be selectively increased.

  In addition, since the second sub reflector is integrally provided on the side of the projection lens of the shade, the structure of the vehicle headlamp can be further simplified, and the second sub reflector is displaced with respect to the shade. Therefore, the reflected light from the second sub-reflector can be accurately irradiated to a predetermined portion of the light distribution pattern.

  According to the second aspect of the present invention, since the reflected light from the second sub-reflector is reflected to the edge portion of the shade, the reflected light from the second sub-reflector is cut-off line formed in the light distribution pattern. The vicinity can be accurately irradiated.

  According to the third aspect of the present invention, since the first sub-reflector is formed integrally with the frame that supports the projection lens, the structure of the vehicle headlamp can be further simplified.

  Hereinafter, a vehicle headlamp according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following, a projector type vehicle headlamp is exemplified.

  1 is a side view of a vehicle headlamp according to the present embodiment, FIG. 2 is an enlarged view of a portion A in FIG. 1, FIG. 3 is a diagram showing a light distribution pattern of the vehicle headlamp, and FIG. It is a graph which shows the cross-sectional illumination intensity in the BB line of FIG. In the drawings, reference sign “VU-VD” indicates vertical lines on the upper and lower sides of the screen, and reference sign “HL-HR” indicates horizontal lines on the left and right sides of the screen (left and right when viewed from the driver side). Yes.

  A vehicle headlamp 10 according to this embodiment includes a bulb 11 having a light emitting unit 11a as a light source, a main reflector 15 that reflects light emitted from the light emitting unit 11a, and reflected light from the main reflector 15 in front. Projector lens (projection lens) 12 that irradiates the projector, a frame 16 to which the projector lens 12 is attached, and a shade that blocks a part of the reflected light from the main reflector 15 toward the projector lens 12 (the lower side in this embodiment). 13.

  As shown in FIG. 1, the bulb 11 is disposed so that the light emitting portion 11 a is positioned on the optical axis O and the bulb axis is coaxial with the optical axis O.

  As the bulb 11, a high pressure metal vapor discharge lamp such as a so-called metal halide lamp, a high intensity discharge lamp (HID), a halogen bulb, an incandescent bulb, or the like is used.

  The main reflector 15 is formed with a substantially elliptical spherical reflecting surface 15a centered on the optical axis O. The reflecting surface 15a is subjected to aluminum vapor deposition or silver coating. A mounting hole 14 for mounting the valve 11 is formed on the rear side of the main reflector 15.

  In the present embodiment, the reflection surface 15a having a substantially elliptic spherical shape has a first focal point F2 positioned substantially at the center of the light emitting portion 11a in a state where the bulb 11 is attached to the attachment hole 14, and a second focal point F3. The shade 13 on the optical axis O is set slightly closer to the projection lens side.

  The projector lens 12 is a convex lens of an aspheric lens. The front side of the projector lens 12 is a convex aspheric surface, and the rear side of the projector lens 12 is a flat aspheric surface. In the present embodiment, the projector lens 12 is attached to a frame 16, and the frame 16 is fixed to the main reflector 15.

  At this time, the projector lens 12 has the focal point F1 of the projector lens 12 at a substantially central portion in the front-rear direction of an edge portion 13b of the shade 13 described later, and the optical axis of the projector lens 12 is substantially the same as the optical axis O of the bulb 11. It is fixed to match.

  Further, in the present embodiment, a first sub-reflector 17 is provided integrally with the frame 16 behind the upper end of the frame 16. That is, as shown in FIG. 1, the first sub reflector 17 is formed in front of the upper end portion of the main reflector 15.

  The first sub-reflector 17 is formed with a reflection surface 17a having a substantially elliptical spherical shape, and this reflection surface 17a is also subjected to aluminum vapor deposition or silver coating.

  The reflecting surface 17a of the first sub-reflector 17 has a first focal point F4 positioned in the vicinity of the light emitting unit 11a, and a second focal point F5 positioned on the optical axis O and closer to the projector lens 12 than the shade 13. It is set to be.

  The shade 13 is disposed in an internal space surrounded by the frame 16, the first sub-reflector 17, and the main reflector 15. The shade 13 blocks the light on the lower side from the light that is reflected by the main reflector 15 and travels toward the projector lens 12. The projector lens 12 is prevented from being irradiated forward and is fixed to the main reflector 15. Specifically, as shown in FIG. 1, the shade 13 is fixed to the main reflector 15 by attaching the lower portion of the shade 13 to the front lower end portion of the main reflector 15.

  In the present embodiment, the shade 13 includes a substantially plate-shaped main body portion 13a, and an edge portion 13b that forms a cut-off line CL in the light distribution pattern is formed on the upper portion of the main body portion 13a. The top surface portion 13c of the edge portion 13b is subjected to aluminum vapor deposition, silver coating, or the like. The light reflected from the upper part of the main reflector 15 and reflected downward is reflected by the top surface portion 13c to be upward light. The reflected light reflected by 13c is irradiated forward through the projector lens 12.

  Further, a substantially plate-like inclined portion (second sub-reflector) 18 that is inclined upward and forward is integrally formed on the projector lens 12 side in the vicinity of the edge portion 13 b of the shade 13.

  The inclined portion 18 is formed such that the tip 18 a of the inclined portion 18 is positioned below the top surface portion 13 c of the shade 13.

  In the present embodiment, the inclined portion 18 is such that the tip 18a of the inclined portion 18 is more than the optical axis O in a state where the shade 13 is fixed to the main reflector 15 so that the top surface portion 13c is positioned slightly above the optical axis O. It is formed so as to be located slightly below.

  The inclined portion 18 is formed in the vicinity of the second focal point F5 of the first sub reflector 17 described above. In the present embodiment, the second focal point F5 of the first sub-reflector 17 is provided at a substantially intermediate position between the front surface 13d of the edge portion 13b and the tip end 18a of the inclined portion 18 in the optical axis O direction.

  The front surface 13d of the edge portion 13b and the rear inclined surface 18b of the inclined portion 18 are also subjected to aluminum vapor deposition or silver coating. Thus, in the present embodiment, the rear inclined surface 18b of the inclined portion 18, the top surface portion 13c of the edge portion 13b, and the front surface 13d are functioned as reflecting surfaces. The rear inclined surface 18b of the inclined portion 18 corresponds to the reflecting surface of the second sub reflector.

  In the present embodiment, the position of the second focal point F5 of the first sub-reflector 17, the angle of light incident on the rear inclined surface 18b from the first sub-reflector 17, the angle of the inclined portion 18 with respect to the main body portion 13a of the shade 13 Are appropriately set, and the light irradiated from the light emitting portion 11a of the bulb 11 and reflected through the first sub-reflector 17, the rear inclined surface 18b, and the front surface 13d of the shade 13 is cut off offline via the projector lens 12. Irradiation is performed along CL.

  In addition, the roughness of the surface of each reflecting surface, the surface treatment method, and the like are set as appropriate, and the reflectance of each reflecting surface is changed, so that the first sub reflector 17, the rear inclined surface 18b, and the front surface 13d of the shade 13 are passed through. It is also possible to adjust the irradiation amount of the reflected light.

  According to the vehicle headlamp 10 having the above configuration, when the bulb 11 is first turned on, the light emitting portion 11a of the bulb 11 emits light. Light is emitted from the light emitting unit 11 a toward the main reflector 15 and the first sub reflector 17.

  At this time, the light irradiated to the main reflector 15 is reflected toward the second focal point F3 of the main reflector 15.

  Here, a part of the light reflected above the horizontal plane including the optical axis O of the main reflector 15 partially passes through the shade 13 and the second focal point of the main reflector 15 positioned in front of the shade 13. The light is condensed at F3, diffused toward the lower part of the projector lens 12 through the second focal point F3, and irradiated forward through the projector lens 12 (see L1 in FIG. 1). Further, a part of the light reflected above the horizontal plane including the optical axis O of the main reflector 15 is reflected by the top surface portion 13c of the shade 13 and becomes upward light to the projector lens 12 positioned in the front. The light is condensed and irradiated forward through the projector lens 12 (see L2 in FIG. 1).

  In addition, the light reflected below the horizontal plane including the optical axis O of the main reflector 15 is blocked by the shade 13 located in front.

  As a result, as shown in FIG. 3, a main light distribution pattern MP having a cut-off line CL is obtained.

  On the other hand, the light emitted to the first sub reflector 17 positioned in front of the main reflector 15 is reflected toward the second focal point F5 of the first sub reflector 17. The light reflected by the first sub-reflector 17 is collected at the second focal point F5, diffused toward the rear inclined surface 18b of the inclined portion 18 provided in the vicinity of the second focal point F5, and the inclined portion. 18 is reflected toward the front surface 13d of the edge portion 13b of the shade 13 by the rear inclined surface 18b. Then, the light reflected by the rear inclined surface 18b of the inclined portion 18 is reflected forward and upward by the front surface 13d of the edge portion 13b, and is irradiated forward through the projector lens 12 (FIG. 1). L3).

  In this way, as shown in FIG. 3, the sub light distribution pattern SP that is distributed along the cut-off line CL is obtained.

  As a result, the light distribution pattern LP (the main light distribution pattern MP and the sub light distribution) of the vehicle headlamp 10 whose illuminance is increased along the cut-off line CL as shown in FIG. And the optical pattern SP).

  Furthermore, in this embodiment, the cross-sectional illuminance in the vicinity of the cut-off line CL is adjusted by adjusting the irradiation position and irradiation amount of the light reflected through the first sub-reflector 17, the rear inclined surface 18b, and the front surface 13d of the shade 13. As shown in FIG. 4, the distribution changes from a broken line (in the case of only the main light distribution pattern MP) to a solid line (in the case where the main light distribution pattern MP and the sub light distribution pattern SP are combined), and in the vicinity of the cut-off line CL. The value obtained by dividing the illuminance gradient at, i.e., the amount of decrease in cross-sectional illuminance by the amount of change in the position in the vertical direction (upward is positive) is made gentle.

  According to the present embodiment described above, the inclination that is disposed in the vicinity of the second focal point F5 of the first sub-reflector 17 and reflects the light reflected by the first sub-reflector 17 toward the front surface 13d of the edge portion 13b of the shade 13 is performed. By providing the portion (second sub-reflector) 18 on the projector lens (projection lens) 12 side of the shade 13, the light emitted from the light-emitting portion (light source) 11a toward the first sub-reflector 17 is changed to the first. A projector lens that reflects from the sub-reflector 17 toward the inclined portion 18, reflects from the rear inclined surface 18 b of the inclined portion 18 toward the front surface 13 d of the shade 13, and is positioned in front of the shade 13 from the front surface 13 d of the shade 13. It becomes possible to reflect the light toward 12. In this way, the light emitted from the light emitting unit 11a toward the first sub-reflector 17 is reflected forward through the first sub-reflector 17, the inclined unit 18 and the shade, and forward through the projector lens 12. By irradiating the light distribution pattern LP, it is possible to obtain a light distribution pattern LP in which the illuminance at a predetermined position of the main light distribution pattern MP is selectively increased, and the visibility of the vehicle headlamp 10 can be improved.

  Further, since the inclined portion 18 is provided integrally on the side of the projector lens 12 of the shade 13, the structure of the vehicle headlamp 10 can be further simplified.

  Further, by providing the inclined portion 18 integrally on the projector lens 12 side of the shade 13, it is possible to suppress the positional displacement of the inclined portion 18 with respect to the shade 13, and the reflected light from the inclined portion 18. Can be accurately applied to a predetermined portion of the light distribution pattern.

  Further, according to the present embodiment, the reflected light from the inclined portion 18 is reflected by the edge portion 13b that forms the cut-off line CL in the main light distribution pattern MP. It is possible to accurately irradiate the vicinity of the cut-off line CL formed in the light distribution pattern MP.

  As a result, it is possible to suppress the light reflected by the edge portion 13b from being irradiated outside the cut-off line CL of the main light distribution pattern MP, and to suppress the occurrence of glare.

  Further, by increasing the illuminance in the region (sub-light distribution pattern SP) along the cut-off line CL formed in the main light distribution pattern MP, the illuminance gradient of the cross-sectional illuminance in the vicinity of the cut-off line CL can be moderated. Therefore, compared to the case of only the main light distribution pattern MP, it is possible to reduce the difference in brightness between the inside and outside of the contour of the light distribution pattern LP in the vicinity of the cut-off line CL, and it is possible to obtain a light distribution pattern that is more uncomfortable. Become.

  Furthermore, according to the present embodiment, since the first sub-reflector 17 is formed integrally with the frame 16 that supports the projector lens 12, the structure of the vehicle headlamp 10 can be further simplified. There are also advantages.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made.

  For example, in the above-described embodiment, the second sub-reflector is provided integrally with the shade, but another second sub-reflector may be provided on the shade.

1 is a side view of a vehicle headlamp according to an embodiment of the present invention. The enlarged view of the A section of FIG. The figure which shows a light distribution pattern. The graph which shows the cross-sectional illumination intensity in the BB line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Projector type head lamp 11 Bulb 11a Light emission part (light source)
12 Projector lens (projection lens)
13 Shade 13b Edge portion 15 Main reflector 16 Frame 17 First sub reflector 18 Inclined portion (second sub reflector)

Claims (3)

A light source;
A main reflector that reflects light from the light source;
A projection lens for irradiating the reflected light from the main reflector forward;
A shade that has an edge portion that forms a cut-off line in the light distribution pattern, and that blocks a part of reflected light from the main reflector toward the projection lens;
A first sub-reflector having a substantially elliptical spherical shape having a first focal point in the vicinity of the light source and a second focal point closer to the projection lens than the shade and disposed between the main reflector and the projection lens When,
A second sub-reflector disposed in the vicinity of the second focal point of the first sub-reflector and reflecting reflected light reflected by the first sub-reflector toward the shade;
With
The vehicle headlamp, wherein the second sub-reflector is integrally provided on the projection lens side of the shade.   2. The vehicle headlamp according to claim 1, wherein the second sub-reflector reflects the reflected light reflected by the first sub-reflector toward an edge portion of the shade.   3. The vehicle headlamp according to claim 1, wherein the first sub-reflector is formed integrally with a frame that supports the projection lens. 4.

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