JP2011054392A - Headlight for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a plurality of synthetic light distribution patterns by a main reflector and a sub-reflector. <P>SOLUTION: The reflector has a reflecting surface of spheroidal shape to reflect light from a light source to the front, and has a cut-out 30 to pass the light from the light source to the outside at part of the reflecting surface. A light shielding plate is arranged between the reflector and the projection lens 20 and cuts off part of reflection light from the reflector and forms a low-beam light distribution pattern having a prescribed cut-off line. A sub-reflector exchange device 50 has a plurality of sub-reflectors 50a-50d which reflect light passing through the cut-out of the reflector to the front and can move any of the sub-reflectors to a position opposed to the cut-out. The plurality of sub-reflectors 50a-50d are combined with the low-beam light distribution pattern and form an additional light distribution pattern so that each of them may have different synthetic light distribution patterns. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a projector-type vehicle headlamp.

  Conventionally, in a projector-type vehicle headlamp, an auxiliary reflector is provided separately from a main reflector, and a light distribution pattern is formed by combining the reflected light of the two. For example, Patent Document 1 is provided with a pair of auxiliary reflectors that reflect light from a light source forward without passing through a condensing lens, on both upper and lower sides of a reflector in a lamp unit including a project-type headlamp. A vehicle headlamp is disclosed. Further, in Patent Document 2, a notch is formed in one part of the reflecting mirror, and a spheroidal auxiliary reflecting surface is disposed outside the reflecting mirror, and the direct light from the light source passing through the notch is the auxiliary reflecting surface. A project-type headlamp is disclosed which is configured to be reflected by the projector and directed toward the projection lens.

JP 2001-195910 A Japanese Patent Laid-Open No. 2001-14908

  However, in the technique described in Patent Document 1, since the auxiliary reflector is fixed, the light distribution pattern cannot be switched in accordance with the situation of the vehicle. Moreover, in the technique 2 described in Patent Document 2, the passing beam distribution and the traveling beam distribution can be switched by rotating the reflecting mirror having a notch in accordance with the auxiliary reflecting surface, but the reflecting mirror itself rotates. Therefore, the number of auxiliary reflecting mirrors is limited, and there is a problem that it is not possible to prepare light distribution patterns according to various vehicle conditions.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technique capable of forming a plurality of combined light distribution patterns in a projector type headlamp having a main reflector and an auxiliary reflector. There is to do.

  One embodiment of the present invention is a vehicle headlamp. This vehicle headlamp has a light source arranged substantially coaxially with an optical axis extending in the vehicle front-rear direction, and a spheroidal reflection surface that reflects light from the light source forward. A reflector having a notch that allows light from the light source to pass to the outside, a projection lens disposed in front of the reflector, and a portion between the reflector and the projection lens to shield part of the reflected light from the reflector And a light shielding plate that forms a low beam distribution pattern having a predetermined cut-off line, and a plurality of sub-reflectors that reflect light that has passed through the cutouts of the reflector to the front, and one of the subreflectors faces the cutout Sub-reflector exchanging means configured to be movable to a position to be moved. The plurality of sub reflectors are combined with the low beam light distribution pattern to form an additional light distribution pattern that is a different combined light distribution pattern.

  According to this aspect, since the sub-reflector exchanging means for moving the sub-reflector to the position facing the notch of the reflector is provided with the reflector fixed, it is not necessary to arrange all the sub-reflectors close to the reflector. Therefore, it becomes possible to prepare more sub-reflectors than before.

  Some of the plurality of sub-reflectors may form an additional light distribution pattern that irradiates a region including the upper part from the cut-off line. Accordingly, various composite light distribution patterns can be formed by combining with the low beam light distribution pattern formed by the reflector and the light shielding plate.

  Two cutouts may be provided at opposite positions on the reflecting surface, and the sub reflector replacement means may be installed corresponding to each cutout. This enables the freedom of light distribution, such as forming the same additional light distribution pattern with two sub-reflectors to increase the illuminance, or forming different additional light distribution patterns to form more complex shaped light distribution patterns. The degree can be increased.

  Select the vehicle status detection means for detecting the situation around the vehicle and the sub-reflector that is moved to the position facing the notch by the sub-reflector replacement means so that a combined light distribution pattern corresponding to the detected situation is formed Pattern determining means for performing the above-described processing. According to this, by selecting an appropriate sub-reflector, it becomes possible to form a combined light distribution pattern according to various vehicle situations with the vehicle headlamp.

  According to the vehicle headlamp of the present invention, various composite light distribution patterns can be formed by installing a large number of sub-reflectors.

It is a schematic sectional drawing explaining the internal structure of the vehicle headlamp which concerns on one Embodiment of this invention. It is a side view explaining a lamp unit and a sub reflector exchange device. It is a schematic sectional drawing in alignment with the AA of FIG. It is a figure explaining the example of the synthetic light distribution pattern formed with a vehicle headlamp.

  FIG. 1 is a schematic cross-sectional view illustrating the internal structure of a vehicle headlamp 100 according to an embodiment of the present invention. FIG. 1 shows a cross section of a vehicular headlamp cut from a vertical plane including the optical axis X of the lamp as viewed from the left side. The vehicle headlamp 100 is a variable light distribution type headlamp that is disposed one by one on the left and right in the vehicle width direction of the vehicle. The structure of the lighting device will be described. The vehicle headlamp 100 has a lamp chamber 26 formed of a lamp body 22 having an opening in the vehicle front direction and a transparent cover 24 covering the front end opening of the lamp body 22. The lamp chamber 26 houses the lamp unit 10 that irradiates light in the forward direction of the vehicle.

  The lamp unit 10 is a lamp called a projector type, and includes a bulb 14 as a light source, a lamp housing 17 that supports a reflector 16 on an inner wall, a projection lens 20, and a light shielding plate 28. As the bulb 14, for example, an incandescent bulb, a halogen lamp, a discharge bulb, an LED, or the like can be used. In the present embodiment, an example in which the bulb 14 is constituted by a halogen lamp is shown. The reflector 16 reflects light emitted from the bulb 14. The bulb 14 is fitted and fixed to an opening formed in the approximate center of the reflector 16 and is supported by the lamp body 22.

  The reflector 16 has an optical axis X extending in the longitudinal direction of the vehicle as a central axis, and has a spheroidal reflecting surface that reflects light from the bulb 14 forward. The reflecting surface is set so that the cross-sectional shape including the optical axis X is an ellipse and the eccentricity gradually increases from the vertical cross section toward the horizontal cross section. The bulb 14 is disposed at the first focal point of the ellipse that constitutes the vertical cross section of the reflecting surface, so that the light from the light source converges on the second focal point of the ellipse.

  The projection lens 20 is a planoconvex aspherical lens having a convex front surface and a flat rear surface, and is disposed on the optical axis X. The projection lens 20 is disposed so that the rear focal point coincides with the second focal point of the reflecting surface of the reflector 16, and is configured to project an image on the rear focal plane as a reverse image on the vertical virtual screen. ing.

  The light shielding plate 28 is disposed between the reflector 16 and the projection lens 20. A part of the light from the bulb 14 and the light reflected by the reflector 16 is shielded by the light shielding plate 28 and guided to the projection lens 20, and a low beam having a predetermined cut-off line on a virtual vertical screen disposed in front of the lamp. Project a light distribution pattern.

  On the inner wall surface of the lamp chamber 26, for example, below the lamp unit 10, light on / off control of the lamp unit 10 or light distribution control for operating a sub-reflector exchange device described later to form a desired combined light distribution pattern is performed. A headlight control unit 40 to be executed is arranged.

  FIG. 2 is a side view illustrating the lamp unit 10 and the sub reflector exchange device 50 according to the present embodiment. The side wall of the lamp unit 10 is formed with a notch 30 that allows light from the bulb 14 to pass outside the unit. A sub reflector replacement device 50 is installed inside the lamp chamber 26 at the side of the lamp unit. The sub-reflector exchange device 50 includes a plurality of sub-reflectors 50a to 50d that reflect light that has passed through the notches 30 formed in the lamp housing 17 to the front of the vehicle.

  In FIG. 2, the sub-reflector exchange device 50 connects the sub-reflectors 50 a to 50 d to each other so as to have a substantially arc shape, and rotates the sub-reflectors 50 a to 50 d around the central axis 52 disposed on the optical axis X. It has a structure to make it. The central shaft 52 of the sub reflector changing device 50 is connected to the output shaft of the motor, and desired sub reflectors 50 a to 50 d can be moved to positions facing the notch 30 by a command from the headlamp control unit 40.

  The sub reflectors 50a to 50d are configured to form an additional light distribution pattern that is combined with a low beam light distribution pattern formed by the reflector 16 and the light shielding plate 28 to form different combined light distribution patterns.

  In FIG. 2, the notch 30 is shown as a rectangular hole, but the shape and size of the notch 30 takes into consideration the amount of light to be given to the sub-reflector and the amount of light to be given to the projection lens 20 in front of the reflector. It is determined.

  FIG. 3 is a schematic cross-sectional view along the line AA in FIG. As shown, the projection lens 20 of the lamp unit and the side walls of the lamp housing 17 are shown in a simplified manner. The notches 30 are respectively provided at opposite positions of the lamp housing 17, that is, on the left and right side walls, and one sub reflector changing device 50 is installed corresponding to each notch. In this way, by installing two sub-reflector exchange devices 50 on the left and right sides, the left and right sub-reflectors can form the same additional light distribution pattern to increase the illuminance, or different additional light distribution patterns can be formed. The degree of freedom of light distribution, such as a more complex synthetic light distribution pattern, can be increased.

  2 and 3, each sub-reflector 50a to 50d is drawn in a rectangle for the sake of brevity, but in actuality, the light reflected by the sub-reflector after passing through the notch 30 is illustrated. 4 has a reflection surface shape that forms an additional light distribution pattern described in 4.

  FIG. 4 shows an example of a combined light distribution pattern projected by the lamp unit 10 onto a virtual vertical screen arranged at a predetermined position ahead, for example, at a position 25 m ahead of the lamp.

  The low beam light distribution pattern Lo is a light distribution pattern formed by the reflector 16 and the light shielding plate 28 as described above. The sub-reflector 50a forms an additional light distribution pattern A1 that overlaps portions of the low beam light distribution pattern Lo from the horizontal line and the vertical line. The sub reflectors 50b to 50d form an additional light distribution pattern that irradiates a region including the upper part from the cutoff line. Of these, the sub-reflector 50b forms an additional light distribution pattern A2 that irradiates slightly above, although the irradiation area is narrower than the additional light distribution pattern A1. The sub-reflector 50c forms an additional light distribution pattern A3 having irradiation areas with substantially the same width on the left and right and top and bottom around the intersection of the horizontal line and the vertical line of the virtual vertical screen. The sub-reflector 50d has an irradiation area equivalent to that of the additional light distribution pattern A3, but forms an additional light distribution pattern A4 that is entirely located on the right side of the vertical line. The combined light distribution patterns 60 to 66 are formed by combining the low beam light distribution pattern Lo and the additional light distribution patterns A1 to A4.

  Among these, the synthetic light distribution pattern 60 is a pattern in which the light amount of the central portion of the low beam where the driver's line of sight concentrates is increased. The combined light distribution pattern 62 is an intermediate beam light distribution pattern that is irradiated with the center and slightly above the low beam light distribution pattern. The synthetic light distribution pattern 64 is a high beam light distribution pattern in which the irradiation range is expanded in order to improve the driver's field of view. The combined light distribution pattern 66 is a right-side high combined light distribution pattern in which only the opposite lane side is a high beam.

  Returning to FIG. 2, the headlamp control unit 40 includes a vehicle condition detection unit 42 and a pattern determination unit 44. These can be realized by hardware using elements such as a CPU and memory of a computer, and can be realized by software such as a computer program loaded in the memory. It is drawn as a functional block. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The vehicle condition detection unit 42 receives information from a camera that detects an object such as a preceding vehicle, an oncoming vehicle, or a pedestrian from a vehicle control unit (not shown), road shape information by a navigation system, and steering that is normally mounted on the vehicle. Information from sensors, vehicle speed sensors, etc. is acquired. Based on these pieces of information, the situation around the host vehicle is detected. Since the detection of the situation around the vehicle is well known, detailed description thereof is omitted.

  The pattern determination unit 44 determines an optimal combined light distribution pattern according to the vehicle situation detected by the vehicle state detection unit 42 from the combined light distribution patterns 60 to 66 shown in FIG. For example, when a preceding vehicle or an oncoming vehicle is detected in front of the host vehicle, the combined light distribution pattern 60 in which the low beam is increased is selected. If there is a preceding vehicle or an oncoming vehicle ahead of the host vehicle, but the distance from the host vehicle is long, the composite light distribution pattern 62 for the intermediate beam is selected. When a preceding vehicle or an oncoming vehicle is not detected in front of the host vehicle, the high beam composite light distribution pattern 64 is selected. Further, when the traffic regulation is a left-hand traffic area and only the preceding vehicle is present and there is no oncoming vehicle or pedestrian, the right side high composite light distribution pattern 66 is selected.

  And the pattern determination part 44 selects the sub reflector moved to the position facing the notch 30 by the sub reflector exchange apparatus 50 so that the determined synthetic | combination light distribution pattern is formed with a vehicle headlamp.

  As described above, according to the present embodiment, the sub-reflector exchanging device that moves the sub-reflector to the position facing the notch of the lamp housing in a state where the reflector is fixed is provided. This eliminates the need to place all the sub-reflectors in close proximity to the reflector, so that it is possible to prepare more sub-reflectors than before.

  Instead of providing notches on the left and right side walls of the lamp housing, notches may be provided on the upper and lower side walls. In this case, one sub-reflector exchange device is also installed above and below the lamp housing. Thus, when the sub-reflector exchange device is arranged vertically, there is an advantage that the additional light distribution pattern can be easily arranged in the vertical direction of the virtual vertical screen.

  The notch may be provided only in one place of the lamp housing. In this case, only one sub reflector exchange device is installed. According to this, since there are few notches, a decrease in the amount of light reflected by the reflector to the projection lens can be suppressed.

  Although the embodiment has been described in which the sub-reflector exchange apparatus has four sub-reflectors, the number of sub-reflectors may be larger or smaller. If the number of sub-reflectors is increased, the types of combined light distribution patterns can be increased.

  In the embodiment, it has been described that the sub-reflector exchanging device adjusts the notch position of the lamp housing by rotating the sub-reflector arranged in an arc shape, but the sub-reflector has another shape, for example, a straight line in the vertical direction. It may be arranged in a shape and may be configured to match the notch position of the lamp housing by moving it up and down. Further, the sub-reflectors may be arranged radially with respect to the rotation axis, and may be configured so as to match the notch position of the lamp housing by rotating the sub reflector.

  The present invention is not limited to the above-described embodiments, and it is possible to combine the embodiments or to add various modifications such as design changes based on the knowledge of those skilled in the art. Embodiments to which modifications are made are also included in the scope of the present invention. Each of the above-described embodiments and a new embodiment resulting from the combination of each of the above-described embodiments and the following modified examples have the effects of the combined embodiments and modified examples.

  DESCRIPTION OF SYMBOLS 10 Lamp unit, 14 Bulb (light source), 16 Reflector, 17 Lamp housing, 20 Projection lens, 28 Shading plate, 30 Notch, 40 Headlamp control part, 50 Sub reflector replacement apparatus, 50a-50d Sub reflector, 100 Vehicle For headlamps.

Claims (4)

A light source disposed substantially coaxially with an optical axis extending in the vehicle longitudinal direction;
A reflector having a spheroidal reflection surface that reflects light from the light source forward, and a notch that allows light from the light source to pass outside in part of the reflection surface;
A projection lens disposed in front of the reflector;
A light shielding plate that is disposed between the reflector and the projection lens and shields a part of the reflected light from the reflector to form a low beam light distribution pattern having a predetermined cutoff line;
Sub-reflector exchanging means having a plurality of sub-reflectors that reflect light that has passed through the notch of the reflector forward, and configured to be able to move any of the sub-reflectors to a position facing the notch;
With
The vehicular headlamp characterized in that the plurality of sub-reflectors form an additional light distribution pattern which is combined with a low beam light distribution pattern to form a different combined light distribution pattern.   2. The vehicle headlamp according to claim 1, wherein a part of the plurality of sub-reflectors forms an additional light distribution pattern that irradiates a region including an upper part from a cut-off line. The notch is provided at two positions opposite to the reflecting surface,
The vehicle headlamp according to claim 1 or 2, wherein the sub-reflector exchange means is installed corresponding to each notch. Vehicle status detection means for detecting the situation around the vehicle;
Pattern determining means for selecting a sub-reflector to be moved to a position facing the notch by the sub-reflector exchanging means so that a combined light distribution pattern according to the detected situation is formed;
The vehicle headlamp according to any one of claims 1 to 3, further comprising:

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