JP2012162105A - Vehicular headlight device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a positional displacement arising from a difference in mounting positions of a preceding vehicle detection means and lights in vehicular headlights in which the optical axes of the lights are adjusted so as to match an upward cut-off line of an additional light distributing pattern with a preceding vehicle.SOLUTION: A left side light and a right side light are constituted so that they can make selective irradiation with a left side additional light distributing pattern or a right side additional light distributing pattern having the upward cut-off line including an area at the left side or right side of the vertical line. The preceding vehicle detection section 52 detects a preceding vehicle from an image photographed by a camera 90. An irradiation direction control section 56 control the irradiation direction of the right and left lights so as to match the lower end of the upward cut-off line of the left side additional light distributing pattern or the right side additional light distributing pattern to the left end or the right end of the preceding vehicle detected by the preceding vehicle detection section 52. A parallax correction section 58 corrects the displacement in the irradiation direction arising from the difference in the installation positions of the camera 90 and the right and left lights on an own vehicle.

Description

  The present invention relates to a vehicle headlamp device.

  In the vehicle headlamp device, in order to improve the visibility of the road surface in front of the vehicle when the vehicle is turning, the lighting unit supported to be rotatable in the left-right direction or the up-down direction is controlled to rotate according to the vehicle traveling condition. There is something that is configured as follows. Each of the left lamp and the right lamp is a light distribution pattern (hereinafter referred to as “a region above the cut-off line of the low beam light distribution pattern, that is, an area above the horizontal line” and including a left or right area of the vertical line. There is also known a vehicle headlamp device that can selectively irradiate either or both of the “additional light distribution pattern” (for example, Patent Document 1). The light distribution pattern is selected according to the vehicle position ahead. According to this, even when a vehicle ahead is present, the area that is irradiated more than the low beam light distribution pattern is formed above the horizontal line, so the irradiation range of the road surface in front of the vehicle without glare on the vehicle ahead Can be enlarged compared with the low beam.

JP 2010-957 A

  In the invention described in Patent Document 1, in order to adjust the position of the vertical line to the left or right vehicle end of the front vehicle when the additional light distribution pattern is irradiated, the front vehicle inspection is installed at the center of the front of the host vehicle. The optical axis directions of the left and right lamps are determined on the basis of information such as an image acquired by the exit means or an inter-vehicle distance. However, since the lamps that actually irradiate the light distribution pattern are provided on the left and right instead of the center of the front part of the host vehicle, it is inevitable that a deviation in the optical axis direction due to a difference in viewpoint occurs.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle headlamp device that adjusts the optical axis direction of a lamp so that the upward cut-off line of the additional light distribution pattern matches the vehicle end of the preceding vehicle. The present invention provides a technique for correcting a deviation in the illumination direction of a lamp caused by a difference between the mounting position of the front vehicle detection means and the lamp.

  In order to solve the above-described problems, the vehicle headlamp device according to an aspect of the present invention includes an upward cut that includes a region above the horizontal cut-off line of the low beam light distribution pattern and on the left side of the vertical line. A left lamp and a right lamp configured to selectively irradiate either or both of a left additional light distribution pattern having an off-line and a right additional light distribution pattern having an upward cut-off line including an area on the right side of the vertical line; A forward vehicle detection means for detecting a forward vehicle, and a lower end of an upward cut-off line on the left side additional light distribution pattern aligned with the left end of the forward vehicle detected by the forward vehicle detection means, and a right side additional light distribution pattern on the right end of the forward vehicle Control means for controlling the irradiation direction of the left lamp and the right lamp so as to match the lower ends of the upward cut-off line, forward vehicle detection means, And a correcting means for correcting the irradiation direction of displacement of the left side lighting device and a right lamp installation position on the vehicle side lamp and the right side lighting device is due to different.

  According to this aspect, since the deviation of the illumination direction of the lamp due to the parallax when the forward vehicle is viewed from the forward vehicle detection means and the left and right lamps is corrected, the lower end of the upward cut-off line of the additional light distribution pattern is Can be approached. Therefore, the visibility on the side of the front vehicle is improved. The “upward cut-off line” includes an arbitrary cut-off line having a vertical component. That is, the upward cut-off line may be vertical or inclined.

  The front vehicle detection means measures the inter-vehicle distance between the front vehicle and the own vehicle, and the correction means uses the measured inter-vehicle distance and the vehicle width of the front vehicle, and uses the center of the own vehicle and the left and right ends of the front vehicle. The angle between the left lamp and the right lamp may be adjusted by the calculated angle.

  According to the present invention, in the vehicle headlamp device that adjusts the optical axis direction of the lamp so that the vertical line of the additional light distribution pattern is aligned with the vehicle end of the preceding vehicle, the front vehicle detection means and the mounting position of the lamp are different. It is possible to correct the deviation of the illumination direction of the lamp due to the above.

1 is a schematic vertical sectional view of a vehicle headlamp device according to an embodiment of the present invention. It is a schematic perspective view of the shade for low beam formation shown in FIG. (A), (b) is a figure explaining the determination of the direction of the optical axis of the left lamp and the right lamp according to the position of the front vehicle. It is a functional block diagram which shows the structure of the headlamp apparatus control part which concerns on one Embodiment. It is a figure explaining the correction method by a parallax correction part.

  FIG. 1 is a schematic vertical sectional view of a vehicle headlamp device 10 according to an embodiment of the present invention. The vehicular headlamp device 10 includes a left lamp provided on the left side of the front end of the vehicle body and a right lamp provided on the right side. FIG. 1 illustrates a left lamp 30L. Hereinafter, the left lamp will be described, but the right lamp basically has the same configuration.

  The vehicular headlamp apparatus 10 has a configuration in which a left lamp 30L is accommodated 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. . The left lamp 30L is attached to the lamp body 12 by a support member (not shown).

  The left side lamp 30L is a lamp called a projector type, and includes a bulb 86 as a light source, a reflector 84, a projection lens 22, and a low beam forming shade 24. The left lamp 30L reflects the light emitted from the bulb 86 to the reflector 84, shields a part of the light traveling forward from the reflector 84 with the low beam forming shade 24, and displays it on the virtual vertical screen disposed in front of the lamp. Project a light distribution pattern with a cut-off line.

  The reflector 84 has a substantially elliptical spherical reflecting surface with the optical axis Ax extending in the vehicle longitudinal direction as the central axis. The reflecting surface is set so that the cross-sectional shape including the optical axis Ax is an ellipse, and the eccentricity gradually increases from the vertical cross section toward the horizontal cross section. The bulb 86 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 22 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, and is disposed on the optical axis Ax. The projection lens 22 is arranged so that the rear focal point coincides with the second focal point of the reflecting surface of the reflector 84, and is configured to project an image on the rear focal plane as an inverted image on the vertical virtual screen. ing. The periphery of the projection lens 22 is held in the front end annular groove of the holder 36.

  As the light source of the lamp, for example, an incandescent bulb, a halogen lamp, a discharge bulb, an LED, or the like can be used. In the present embodiment, a bulb 86 configured by a halogen lamp is shown as an example. The bulb 86 is fitted and fixed to an opening formed in the approximate center of the reflector 84 and is supported by the lamp body 12.

  The vehicular headlamp device 10 is a switching type headlamp that can produce both a low beam light distribution pattern and a high beam light distribution pattern by providing a low beam forming shade 24 inside the lamp.

  The left lamp 30L includes a shade 24 that blocks a part of the light emitted from the bulb 86 and forms a low beam light distribution pattern. The shade 24 is composed of subshades that are divided into two in the horizontal direction. A rotating body 26 that is rotationally driven by a subshade drive motor 32 is attached to the lower end of each subshade. When both sub-shades are upright, a low beam light distribution pattern is formed. When the rotating body 26 is rotated to tilt both subshades substantially horizontally, a high beam light distribution pattern is formed. The structure and operation of the shade will be described in detail with reference to FIG.

  The vehicle headlamp device 10 also includes a swivel motor 34 that changes the angle of the optical axis Ax of the left lamp 30L in response to a command from an irradiation direction control unit 56 described later. The lamp 30L is held by the lamp body 12 so as to be swingable at least in the left-right direction. The swivel motor 34 is attached to the lower bottom portion of the holder 36 and supports the entire lamp so as to be rotatable around a shaft 47.

  FIG. 2 is a schematic perspective view of the low beam forming shade 24 shown in FIG. As described above, the low beam forming shade 24 is divided into two subshades 24 a and 24 b by the dividing groove 44 passing through the elbow point 45. The subshades 24a and 24b have a right side portion 47d that extends horizontally below the horizontal line that crosses the optical axis on the right side in the vehicle width direction so that a so-called cut-off line is formed in the low beam light distribution pattern when both shades are upright. And a left portion 47f extending horizontally at a position slightly above the right portion on the left side in the vehicle width direction has a shape connected by a central portion 47e inclined upward to the left. The inclination angle of the central portion is, for example, 45 °.

  Rotating bodies 26a and 26b that are rotatably supported by a support shaft 28 are attached to the lower ends of the sub-shades 24a and 24b. The support shaft 28 is connected to a side wall (not shown) extending from the holder 36 and can be swiveled integrally with the holder 36. Each of the rotating bodies 26a and 26b is connected to a drive shaft (not shown) of the sub-shade drive motor 32 via a transmission mechanism (not shown) such as a gear, a belt, and a chain. It is possible to rotate each individually in response to a command from.

In another embodiment, a motor is incorporated in each of the rotators 26a and 26b itself, and may be configured to be rotatable around the support shaft 28 in response to a command from the headlamp device controller 40.
In another embodiment, a solenoid having a drive shaft connected to the surface of the sub-shade may be arranged on either side of the front and rear surfaces of the sub-shades 24a and 24b. In this case, when the solenoid is actuated in accordance with a command from the headlamp device control unit 40, the drive shaft extends to open the sub-shades 24a and 24b, and when the solenoid is deactivated, the drive shaft retracts and the sub-shade 24a , 24b are returned to the upright state.

  In still another embodiment, instead of the low beam forming shade, a so-called rotary shade in which a plurality of sub-shades having different shielding areas are attached to the circumferential side surface of the rotating shaft at intervals may be provided in the lamp. In this case, the shielding area of each sub-shade is made equal to the above-described sub-shade 24a and sub-shade 24b. By rotating the rotary shaft of such a rotary shade so that one of the sub-shades is brought into focus with the reflector, a light distribution pattern similar to the case where the above-described sub-shades 24a and 24b are provided can be created.

  The headlamp device control unit 40 controls the turning-off of the left lamp 30L and the right lamp 30R, the operation of each sub-shade provided in the lamp, and the optical axis direction (swivel) of each lamp. When a high beam is selected by the driver and the front vehicle is detected based on the image captured by the camera that images the front of the vehicle, the headlamp device control unit 40 displays two sub-shades in the left and right lamps. Either a left high beam light distribution pattern (also referred to as a left additional light distribution pattern), a right high beam light distribution pattern (also referred to as a right additional light distribution pattern), or a low beam light distribution pattern is formed in an upright or inclined manner. To be.

  When the left high beam light distribution pattern is selected, the headlight device control unit 40 adjusts the left and right lamps so that the detected left end of the front vehicle is aligned with the vertical cut-off line of the left high beam light distribution pattern. Controls the optical axis direction. When the right high beam light distribution pattern is selected, the headlamp device controller 40 adjusts the right and left lamps so that the detected right end of the front vehicle is aligned with the vertical cutoff line of the right high beam light distribution pattern. Controls the optical axis direction. In the following description, “preceding vehicle” refers to a vehicle in front of the host vehicle traveling in the own lane, and “oncoming vehicle” refers to a vehicle in front of the host vehicle traveling in the opposite lane. The preceding vehicle and the oncoming vehicle are collectively referred to as the “front vehicle”.

  FIGS. 3A and 3B are diagrams for explaining the determination of the directions of the optical axes of the left lamp 30L and the right lamp 30R according to the position of the front vehicle by the headlamp device controller 40. FIG. FIGS. 3A and 3B show a light distribution pattern formed on a virtual vertical screen arranged at a position 25 m ahead of the vehicle headlamp device 10. In addition, the light distribution pattern shown to Fig.3 (a), (b) is a synthetic | combination light distribution pattern formed by superimposing the light distribution pattern formed with the left lamp 30L and the right lamp 30R, respectively.

  FIG. 3A shows a left-side high beam light distribution pattern LHi used in an area where traffic regulations are left-hand traffic. The left high beam distribution pattern LHi is formed by, for example, combining a left high beam distribution pattern formed by the left lamp 30L and a low beam distribution pattern formed by the right lamp 30R. Such a left high beam light distribution pattern LHi is a light distribution suitable for the case where there is no forward vehicle or pedestrian on the own lane side, and there is an oncoming vehicle or pedestrian on the opposite lane side. This light distribution pattern is designed to improve the forward visibility of the vehicle and to prevent glare from oncoming vehicles and pedestrians in the oncoming lane.

  FIG. 3B shows a right-side high beam light distribution pattern RHi used in an area where traffic regulations are left-hand traffic. This right high beam light distribution pattern RHi is formed, for example, by combining a right high beam light distribution pattern formed by the right lamp 30R and a low beam light distribution pattern formed by the left lamp 30L. The right-side high beam light distribution pattern RHi is a light distribution suitable for the case where there are forward vehicles and pedestrians on the own lane side, and there are no oncoming vehicles and pedestrians on the opposite lane side. This light distribution pattern is designed to improve glare and not to give glare to pedestrians in the front car or in the own lane.

  As shown in FIGS. 3A and 3B, the headlamp device control unit 40 causes the front vehicle to follow the vertical cut-off line LC of the light distribution pattern at the left end or the right end of the front vehicle. Swivel the optical axis of the left and right lamps. Thereby, the irradiation range of the road surface ahead can be expanded without giving glare to the driver of the vehicle ahead.

  By the way, when the optical axis direction is controlled so that the vertical cut-off line of the additional light distribution pattern is aligned with the left and right vehicle ends of the front vehicle based on the captured image of the front vehicle, there are the following problems. The camera that images the vehicle ahead is usually installed at the center of the front of the vehicle. On the other hand, the lamps whose optical axis directions are controlled are respectively installed on the left end side and the right end side of the vehicle. Due to such a configuration, the angle of the forward vehicle viewed from the camera, which is obtained from the analysis of the captured image, and the direction of the forward vehicle viewed from each lamp are slightly different. Because of this angle shift, even if control is performed so that the vertical cut-off line is aligned with the left and right vehicle ends of the forward vehicle based on the captured image, a shift will actually occur between the two.

  Therefore, in the present embodiment, the angle deviation between the direction of the forward vehicle viewed from the camera and the direction of the forward vehicle viewed from each lamp is calculated, and the optical axis direction of the lamp is corrected by this angle. I made it.

  FIG. 4 is a functional block diagram showing a configuration of the headlamp device control unit 40 according to the present embodiment. Each block shown here can be realized in hardware by an element such as a computer CPU or memory, a mechanical device, and an electric circuit, and in software by a computer program or the like. It is drawn as a functional block realized by the cooperation. 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 forward vehicle detection unit 52 detects a position occupied by the forward vehicle based on an image captured by a CCD (Charge Coupled Device) camera 90 installed at the center of the front of the vehicle so as to capture the front of the vehicle. Specifically, the forward vehicle detection unit 52 detects a portion corresponding to the headlight or taillight of the vehicle in an image ahead of the vehicle acquired by the camera 90 according to a known algorithm, and The vehicle position is determined in light of the horizontal line (HH) and the vertical line (V-V). The vehicle position data is output to the sub shade drive unit 54. Since a method for detecting a forward vehicle from a captured image of such a camera is well known, detailed description thereof is omitted here. Instead of the camera 90, the position of the preceding vehicle may be detected using other detection means such as a millimeter wave radar or an infrared radar.

  Further, the forward vehicle detection unit 52 analyzes the captured image of the camera 90 or measures the detection time of reflection by the forward vehicle such as a millimeter wave radar or an infrared radar, so Measure the distance between cars. Since such a method for measuring the inter-vehicle distance is also well known, detailed description thereof will be omitted. The forward vehicle detection unit 52 may further obtain the vehicle width W of the forward vehicle from the captured image of the camera 90.

  The sub-shade drive unit 54 instructs the sub-shade drive motor 32 to move both the low-shade forming sub-shades 24a and 24b to the upright position when the driver instructs the low beam with the headlight switch. Thereby, irradiation is performed with the light distribution pattern for low beam. When the driver instructs the high beam, the sub-shade drive unit 54 instructs the sub-shade drive motor 32 to incline both the sub-shades 24a and 24b for forming the low beam. Thereby, irradiation is performed with the light distribution pattern for high beams.

  Further, the sub-shade drive unit 54 has a light distribution area having a light-shielding region corresponding to the detected vehicle position when a high beam is selected by the driver and a forward vehicle is detected by the forward vehicle detection unit 52. It is determined which of the sub-shades 24a and 24b should be erected so as to form a pattern, and an instruction corresponding to this is given to the sub-shade drive motor 32. That is, the sub-shade drive unit 54 is configured such that the left high beam light distribution pattern is formed by both the left lamp 30L and the right lamp 30R when the preceding vehicle is not detected by the forward vehicle detection unit 52 and the oncoming vehicle is detected. The sub shade drive motor 32 is controlled. When the oncoming vehicle is not detected by the preceding vehicle detection unit 52 and the preceding vehicle is detected, the sub-shade driving unit 54 performs the sub-light so that the right high beam light distribution pattern is formed by both the left lamp 30L and the right lamp 30R. The shade drive motor 32 is controlled.

  The irradiation direction control unit 56 determines the directions of the optical axes of the left lamp 30L and the right lamp 30R according to the position of the front vehicle detected by the front vehicle detection unit 52. More specifically, when there is a front vehicle, the left lamp 30L and the right lamp 30R such that the vertical cut-off line of the left high beam light distribution pattern or the right high beam light distribution pattern is aligned with the left end or right end of the front vehicle. Determine the direction of the optical axis. Further, the irradiation direction control unit 56 determines the swivel angle of each lamp so that the optical axes of the left lamp 30L and the right lamp 30R face the determined direction, and sends a drive signal corresponding to the angle to the swivel motor 34.

  The parallax correction unit 58 corrects the deviation in the irradiation direction of the left lamp 30L and the right lamp 30R caused by the installation positions of the front vehicle detection unit 52, the left lamp, and the right lamp on the vehicle being different.

A correction method by the parallax correction unit 58 will be described with reference to FIG. As shown in the figure, a camera 90 that captures an image of the forward vehicle 80 is provided at the center of the front portion of the host vehicle 50, and a left lamp 30L and a right lamp 30R are provided at the left and right ends, respectively. Direction when viewed left and right ends of the front wheel 80 from the camera 90, are respectively represented by arrows B _L, B _R. In the direction the arrow C _L when the left side lighting device 30L viewed leftmost front wheel 80, the direction when viewing the right end of the front wheel 80 from the right side lighting device 30R is represented by arrow C _R.

When viewed front wheel from the camera 90, the direction B _L when viewed left and right _ends, B _R is a an angle θ respect to the line connecting the centers of both car (represented by dotted lines). Accordingly, when defining an optical axis direction of the left and right lamp on the basis of the image of the camera 90, an arrow D _L in the _figure, as indicated respectively by D _R, the optical axis direction of the left side lighting device 30L in the left direction outward by theta, right lamp The optical axis direction of 30R is shifted rightward outward by θ. As a result, an error indicated by Δ in the figure occurs between the left high beam light distribution pattern and the left end of the front vehicle 80 and between the right high beam light distribution pattern and the right end of the front vehicle 80.

Therefore, the parallax correction unit 58 uses the inter-vehicle distance L (m) measured by the front vehicle detection unit 52 and the vehicle width W (m) of the front vehicle to determine the center of the host vehicle and the left and right ends of the front vehicle. The angle θ formed may be calculated. The following relationship is derived geometrically.
θ≈tan ⁻¹ {(W / 2) / L} (1)
A constant may be used for the vehicle width of the preceding vehicle. If W≈2 (m), the following equation is obtained.
θ≈tan ⁻¹ (1 / L) (2)

  Θ calculated in this way is given from the parallax correction unit 58 to the irradiation direction control unit 56. The irradiation direction control unit 56 shifts the optical axis direction of the left lamp 30L to the right by the angle θ given from the angle determined based on the detection result of the front vehicle detection unit 52. Further, the optical axis direction of the right lamp 30R is shifted to the left side by an angle θ from the angle determined based on the detection result of the front vehicle detection unit 52. Thereby, the error Δ in the figure is eliminated, and the vertical cut-off line of the left high beam light distribution pattern and the right high beam light distribution pattern can be brought closer to the vehicle end of the preceding vehicle. If it carries out like this, since the right-and-left vicinity of a front vehicle can be illuminated, the visibility at the time of additional light distribution pattern irradiation improves.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The configuration shown in each figure is for explaining an example, and any configuration that can achieve the same function can be changed as appropriate, and the same effect can be obtained.

  In the embodiment, it has been described that the irradiation directions of the left lamp and the right lamp are controlled so that the vertical cutoff lines of the left high beam light distribution pattern and the right high beam light distribution pattern coincide with the vehicle end of the front vehicle. However, the present invention can also be applied to an arbitrary light distribution pattern having a cut-off line having a vertical component (hereinafter referred to as “upward cut-off line”). For example, the present invention is also applied to a light distribution pattern in which the vertical lines LC of the left high beam light distribution pattern LHi or the right high beam light distribution pattern RHi shown in FIG. it can. In this case, the irradiation direction control unit 56 and the parallax correction unit 58 of the headlamp device control unit 40 may perform control so that the lower end of the upward cutoff line of each light distribution pattern coincides with the vehicle end of the preceding vehicle.

  DESCRIPTION OF SYMBOLS 10 Vehicle headlamp device, 22 Projection lens, 24 Low beam formation shade, 24a, 24b Sub shade, 26a, 26b Rotating body, 28 Support shaft, 30L Left lamp, 30R Right lamp, 32 Sub shade drive motor, 34 Swivel Motor, 40 headlamp device control unit, 44 dividing groove, 50 own vehicle, 52 forward vehicle detection unit, 54 subshade drive unit, 56 irradiation direction control unit, 58 parallax correction unit, 90 camera.

Claims (3)

An upward cut that includes an additional light distribution pattern on the left side and an area on the right side of the vertical line, each having an upward cut-off line that is above the horizontal cutoff line of the low beam light distribution pattern and includes a region on the left side of the vertical line. A left lamp and a right lamp configured to selectively irradiate either or both of the right additional light distribution pattern having an off-line; and
Forward vehicle detection means for detecting a forward vehicle;
The lower end of the upper cut-off line on the left side additional light distribution pattern is made to coincide with the left end of the front car detected by the front vehicle detecting means, and the lower end of the upper cut-off line on the right side additional light distribution pattern is made to coincide with the right end of the front car. Control means for controlling the irradiation direction of the left lamp and the right lamp,
Correction means for correcting a deviation in the irradiation direction of the left lamp and the right lamp caused by different installation positions of the front vehicle detection means and the left lamp and the right lamp on the vehicle;
A vehicle headlamp device comprising: The forward vehicle detecting means measures a distance between the forward vehicle and the own vehicle;
The correction means calculates an angle formed by the center of the host vehicle and the left and right ends of the front vehicle using the measured inter-vehicle distance and the vehicle width of the front vehicle,
The vehicle headlamp device according to claim 1, wherein the control means adjusts the irradiation direction of the left lamp and the right lamp by a calculated angle.   The vehicle headlamp device according to claim 2, wherein a constant is used as a vehicle width of the preceding vehicle.

Images