JP2011143822A - Light distribution control system of vehicle headlamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply a proper light distribution pattern corresponding to a travel environment by a simple technique. <P>SOLUTION: This light distribution control system 100 includes a vehicle headlamp 10 capable of selectively applying a light distribution pattern for an urban district and a light distribution pattern for the suburbs, a light emitter detecting part 46 for detecting a light emitter existing in front of a vehicle, and an application control part 44 for controlling the vehicle headlamp 10 so as to apply the light distribution pattern for the suburbs when the number of detected light emitters is smaller than a predetermined value and apply the light distribution pattern for the urban district when the number of detected light emitters is a predetermined number or larger. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light distribution control system for controlling the light distribution of a vehicle headlamp.

  Conventionally, the presence or absence of a preceding vehicle or an oncoming vehicle (hereinafter referred to as “front vehicle” as appropriate) is detected based on an image in front of the vehicle imaged by a camera, and the light distribution pattern is changed based on the detection result. A vehicular headlamp configured to be used has been proposed (see, for example, Patent Documents 1 and 2).

JP 2008-94127 A JP 2008-37240 A

  By the way, in the vehicle headlamp as described above, the detection of the front vehicle is usually performed by detecting light from the headlamp or tail lamp of the front vehicle. While traveling, the position of the front car changes every moment and the light from the front car may be weak, so it is not easy to accurately detect the front car.

  The present invention has been made in view of such a situation, and an object thereof is to provide a light distribution control system for a vehicle headlamp that can irradiate an appropriate light distribution pattern according to a traveling environment by a simple method. There is to do.

  In order to solve the above problems, a vehicle headlamp light distribution control system according to an aspect of the present invention includes a vehicle headlamp capable of selectively irradiating an urban area light distribution pattern and a suburban light distribution pattern; Detecting means for detecting illuminants existing in front of the vehicle, and irradiating an urban area light distribution pattern when the number of detected illuminants is greater than or equal to a predetermined value, and suburban light distribution when the number is less than the predetermined value And a control means for controlling the vehicle headlamp to irradiate with a pattern.

  The present invention is based on the knowledge that when the number of light emitters present in front of the vehicle is large, the possibility of traveling in an urban area is high, and when the number is small, the possibility of traveling in a suburb is high. According to this aspect, the irradiation of an appropriate light distribution pattern according to the traveling environment of the vehicle is performed using a technique that is simpler than the detection of the preceding vehicle, which simply counts the number of light emitters existing in front of the vehicle. It becomes possible.

  The detecting means may detect a light emitter having a polygonal outer shape. The detecting means may detect a light emitter having a substantially constant luminance over the entire light emitting area. The detecting means may detect a light emitter that exists along a road ahead of the vehicle. Such a light emitter is highly likely to be a signboard present along the roadside, and when there are many signboards, it is highly likely that the sign is traveling in an urban area. Therefore, by configuring the detection means to detect such a light emitter, the determination accuracy of the traveling environment of the vehicle is increased, and a more appropriate light distribution pattern can be emitted.

  The control means may select a light distribution pattern to be irradiated based on the number of light emitters detected within a predetermined time. Thus, by counting the number of light emitters over a certain period of time, the determination accuracy of the traveling environment of the vehicle is increased, and a more appropriate light distribution pattern can be emitted.

  ADVANTAGE OF THE INVENTION According to this invention, the light distribution control system of the vehicle headlamp which can irradiate the suitable light distribution pattern according to driving | running | working environment with a simple method can be provided.

1 is a schematic horizontal sectional view of a vehicle headlamp used in a light distribution control system according to an embodiment of the present invention. It is a figure for demonstrating the light distribution pattern formed with the vehicle headlamp. It is a functional block diagram for demonstrating the light distribution control system of the vehicle headlamp which concerns on embodiment of this invention. It is a figure which shows the flowchart for demonstrating the switching control of the light distribution pattern in this embodiment.

  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. 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.

  FIG. 1 is a schematic horizontal sectional view of a vehicle headlamp 10 used in a light distribution control system according to an embodiment of the present invention.

  The vehicle headlamp 10 according to the present embodiment includes a low beam lamp 20L and a high beam lamp in a lamp chamber formed by a lamp body 12 and a translucent cover 14 attached to a front end opening of the lamp body 12. 20H is accommodated. Hereinafter, the low beam lamp 20L and the high beam lamp 20H are collectively referred to as a “lamp”. Each lamp is attached to the lamp body 12 by a support member (not shown). Further, an extension member 16 having an opening in an area where the lamp is present is fixed to the lamp body 12 or the translucent cover 14, and an area between the front opening of the lamp body 12 and the lamp is covered with respect to the front. .

  The low beam lamp 20L is a conventionally known reflection type lamp, and includes a light source bulb 21 and a reflector 23. The low beam lamp 20L reflects the light emitted from the light source bulb 21 to the reflector 23, cuts a part of the light traveling forward from the reflector 23 with a light shielding plate (not shown), and has a predetermined cut-off line. A light pattern is formed. A shade 25 is provided at the tip of the light source bulb 21 to cut the light emitted directly from the light source bulb 21 forward. The shape of the low beam lamp 20L is not particularly limited to this, and may be a projector-type lamp similar to the high beam lamp 20H described later.

  The high beam lamp 20H is a projector-type lamp, and includes a projection lens 22, a light source unit 24 including a light source 26 for high beam irradiation, and a holder 28 that holds the projection lens 22 and the light source unit 24. The projection lens 22 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, and is disposed on an optical axis Ax extending in the vehicle front-rear direction. The projection lens 22 is configured to project an image on the rear focal plane including the rear focal point F as a reverse image on a vertical virtual screen disposed in front of the lamp. The periphery of the projection lens 22 is held in the front end annular groove of the holder 28.

  The light source unit 24 is held on the rear end side of the holder 28 in a state where the light source 26 is disposed rearward of the rear focal point F of the projection lens 22 so that the light source 26 faces frontward in the optical axis Ax direction. The light source unit 24 directly irradiates light from the light source 26 toward the projection lens 22. The holder 28 is attached to the lamp body 12 via a support member (not shown). The light source 26 may be, for example, a light emitting diode (LED).

  FIG. 2 is a diagram for explaining a light distribution pattern formed by the vehicle headlamp 10. FIG. 2 is a diagram showing the front of the vehicle seen through when the vehicle is traveling on a straight paved road with one lane on one side (two lanes on both sides). FIG. 6 is a diagram showing a low beam light distribution pattern PL and a high beam light distribution pattern PH formed on a virtual vertical screen arranged at a position 25 m ahead of the vehicle. FIG. 2 also shows the center line CL, the own lane side line MRL, and the opposite lane side line ORL. The own lane side line MRL extends in the lower left direction from the HV point (intersection of the horizontal line HH and the vertical line VV), which is the vanishing point of the perspective view, and the center line CL and the opposite lane side line ORL. Extends downward from the HV point. Further, FIG. 2 shows a plurality of light emitters 30 provided along the road. The light emitting body 30 is a light emitting body having a rectangular outer shape, and represents, for example, a signboard such as a convenience store erected along the road.

  The low beam light distribution pattern PL is formed by the irradiation light from the low beam lamp 20L. The light distribution pattern PL for the low beam shown in FIG. 2 is a light distribution pattern that is considered to prevent glare from oncoming vehicles and pedestrians during driving such as urban driving in areas where traffic regulations are left-hand traffic. Cut-off lines CL1, CL2, and CL3 having different left and right steps are provided at the upper edge. The cut-off line CL1 is formed on the right side of the vertical line V-V so as to extend in the horizontal direction as an oncoming lane side cut-off line. The cut-off line CL2 is formed on the left side of the vertical line VV so as to extend in the horizontal direction at a position higher than the cut-off line CL1 as the own lane side cut-off line. The cut-off line CL3 is formed as an oblique cut-off line that connects the end of the cut-off line CL2 on the vertical line VV side and the end of the cut-off line CL1 on the vertical line VV side. The cut-off line CL3 extends from the intersection of the cut-off line CL1 and the vertical line VV obliquely upward to the left with an inclination angle of 45 °.

  The high beam light distribution pattern PH is formed by irradiation light from the high beam lamp 20H. The high beam light distribution pattern PH is formed in addition to the low beam light distribution pattern PL. As shown in FIG. 2, the high-beam light distribution pattern PH is a light distribution pattern that irradiates the vicinity of the horizontal line HH and the region above it over a wide range on the left and right. When the light distribution pattern for low beam PL is irradiated, the light distribution pattern for improving the visibility of the road surface of the vehicle can be formed by adding the light distribution pattern for high beam PH to the light distribution pattern for low beam PL. it can.

  FIG. 3 is a functional block diagram for explaining the light distribution control system 100 for a vehicle headlamp according to the embodiment of the present invention. The light distribution control system 100 includes the vehicle headlamp 10 described above, a camera 40 for imaging the front of the vehicle, an image processing unit 42, and an irradiation control unit 44.

  The irradiation control unit 44 controls irradiation of the vehicle headlamp 10. The irradiation controller 44 turns on / off the low beam lamp 20L and the high beam lamp 20H of the vehicle headlamp 10 according to instructions from the driver. For example, when an instruction for low beam irradiation is given from the driver, the irradiation control unit 44 turns on the light source bulb 21 of the low beam lamp 20L and irradiates the low beam light distribution pattern PL. When the driver gives an instruction for high beam irradiation, the irradiation control unit 44 turns on the light source 26 of the high beam lamp 20H in addition to the light source bulb 21, and the low beam light distribution pattern PL and the high beam light distribution pattern PH. Irradiate. Such an instruction from the driver is given via a light switch (not shown). Hereinafter, the mode in which the light distribution pattern is controlled in accordance with an instruction from the driver in this manner is appropriately referred to as “manual mode”.

  The camera 40 shown in FIG. 3 is configured to image the front of the vehicle at a predetermined cycle. An image captured by the camera 40 is sent to the image processing unit 42.

  The image processor 42 includes a light emitter detector 46 and a light emitter counter 48. The illuminant detection unit 46 detects the illuminant 30 having a rectangular outer shape based on the image captured by the camera 40. The detection of the rectangular light emitter 30 can be performed by applying a known image recognition technique such as pattern matching. The illuminant counting unit 48 counts the number of square illuminants 30 detected by the illuminant counting unit 48. Information on the number of square light emitters 30 counted by the light emitter counter 48 is sent to the irradiation controller 44.

  In addition to the manual mode as described above, the irradiation control unit 44 has a mode in which the light distribution pattern is automatically switched according to the situation around the vehicle, regardless of the operation of the light switch. Hereinafter, the mode for controlling the light distribution pattern in this way is appropriately referred to as an “ADB (Adaptive Driving Beam) mode”.

  In the ADB mode, the irradiation controller 44 irradiates the low-beam light distribution pattern PL as the urban light distribution pattern when the number of the rectangular light emitters 30 counted by the light emitter counter 48 is equal to or greater than a predetermined value. . Further, when the number of the light emitters 30 in the quadrangle counted by the light emitter counter 48 is less than a predetermined value, the irradiation controller 44 distributes the high beam light distribution to the low beam light distribution pattern PL as the suburban light distribution pattern. The light distribution pattern to which the pattern PH is added is irradiated.

  If there are a large number of quadrilateral light emitters 30 in front of the vehicle, it means that there are a large number of signboards, so there is a high possibility that the vehicle is traveling in an urban area. high. Therefore, it is determined whether the environment in which the vehicle is traveling is an urban area or a suburb based on the number of square light emitters 30, and the light distribution pattern suitable for each is irradiated by switching the light distribution pattern. Can do.

  The above-mentioned predetermined value for determining the urban area and the suburb can be appropriately set according to the place where the vehicle mainly travels, but may be, for example, about 5 to 10. For example, when the predetermined value is set to 5, in the example of FIG. 2, since the number of the rectangular light emitters 30 is three, the irradiation control unit 44 determines that the vehicle is traveling in the suburbs, and is used for the low beam. The light distribution pattern obtained by adding the high-beam light distribution pattern PH to the light distribution pattern PL is irradiated.

  FIG. 4 is a flowchart for explaining light distribution pattern switching control according to this embodiment. The flow shown in FIG. 4 is repeatedly executed at predetermined intervals.

  First, the image processing unit 42 acquires image data from the camera 40 (S10). The illuminant detection unit 46 of the image processing unit 42 detects the illuminant 30 having a rectangular outer shape based on the image data, and the illuminant counting unit 48 counts the number of detected illuminant 30 having the square shape (S12). .

  The irradiation controller 44 determines whether or not the number of the rectangular light emitters 30 is equal to or greater than a predetermined value (S14). When the number of the rectangular light emitters 30 is equal to or greater than the predetermined value (Y in S14), the irradiation control unit 44 irradiates the urban light distribution pattern (S16). That is, in this embodiment, the low beam light distribution pattern PL is irradiated.

  On the other hand, if the number of square light emitters 30 is less than the predetermined value (N in S14), the suburban light distribution pattern is irradiated (S18). That is, in the present embodiment, a light distribution pattern obtained by adding the high beam light distribution pattern PH to the low beam light distribution pattern PL is irradiated.

  As described above, according to the light distribution control system 100 according to the present embodiment, a technique that is simpler than the detection of a preceding vehicle is used, which simply counts the number of square light emitters 30 existing in front of the vehicle. Thus, it is possible to irradiate an appropriate light distribution pattern according to the traveling environment of the vehicle.

  In the above-described embodiment, the illuminant detection unit 46 is configured to detect the quadrilateral illuminant 30, but the illuminant detection unit 46 is not limited to the tetragonal shape, and the light emission of an arbitrary polygonal shape. It may be configured to detect a body. In addition, since the light-emitting body with a circular outer shape may be a road sign, it is preferable to exclude from a detection target.

  Further, the light emitter detection unit 46 may be configured to detect a light emitter having a substantially constant luminance over the entire light emitting area. Furthermore, the light emitter detection unit 46 may be configured to detect a light emitter present along a road ahead of the vehicle. Since such a light emitter is highly likely to be a signboard such as a convenience store erected along the roadside, it is possible to increase the determination accuracy of the urban area.

  Further, the irradiation control unit 44 may select a light distribution pattern to be irradiated based on the number of light emitters detected within a predetermined time. For example, in the above-described embodiment, the number of the light emitters 30 is detected based on the image data obtained by one imaging. However, the light emitter 30 is based on a plurality of image data obtained by performing the imaging several times. May be detected. Thus, by counting the number of light emitters over a certain period of time, the determination accuracy of the traveling environment of the vehicle is increased, and a more appropriate light distribution pattern can be emitted.

  Further, in the above-described embodiment, the illuminant to be detected is limited to a rectangular one, but the outer shape, position, luminance, etc. of the illuminant are not particularly limited, and the number of illuminants in the acquired image is counted. It is good also as composition to do. The light emitter may include a vehicle headlamp or other illumination light, that is, light detected by the light emitter detector 46 by indirect illumination. In this case, light sources such as a tail lamp of a preceding vehicle and a traffic light are counted, but when the number of the preceding vehicle and traffic signals is large, it can be determined that the vehicle is traveling in an urban area.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

  For example, the illuminant detection unit 46 may have a function of recognizing characters such as hiragana and kanji, and the illuminant counting unit 48 may be configured to count the number of illuminants in which characters exist. . Since such a light emitter is highly likely to be a signboard, it can be accurately determined that it is traveling in an urban area if a certain number or more exist.

  DESCRIPTION OF SYMBOLS 10 Vehicle headlamp, 20L Low beam lamp, 20H High beam lamp, 21 Light source bulb, 26 Light source, 30 Light emitter, 40 Camera, 42 Image processing part, 44 Irradiation control part, 46 Light emitter detection part, 48 Light emitter Counting unit, 100 light distribution control system.

Claims (5)

A vehicle headlamp capable of selectively illuminating an urban light distribution pattern and a suburban light distribution pattern;
Detection means for detecting a light emitter existing in front of the vehicle;
Control for controlling the vehicular headlamp to irradiate an urban light distribution pattern when the number of detected light emitters is equal to or greater than a predetermined value, and to irradiate with a suburban light distribution pattern when the number is less than a predetermined value Means,
A vehicle headlamp light distribution control system comprising:   The light distribution control system for a vehicle headlamp according to claim 1, wherein the detection means detects a light emitter having a polygonal outer shape.   The light distribution control system for a vehicle headlamp according to claim 1, wherein the detection unit detects a light emitter having a substantially constant luminance over the entire light emission area.   The light distribution control system for a vehicle headlamp according to any one of claims 1 to 3, wherein the detecting means detects a light emitter existing along a road ahead of the vehicle.   5. The vehicle headlamp distribution according to claim 1, wherein the control means selects a light distribution pattern to be irradiated based on the number of light emitters detected within a predetermined time. Light control system.

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