JP7652126B2 - Vehicle headlamp control device - Google Patents

Description

The present invention relates to a vehicle headlamp control device.

Patent document 1 discloses a light control device that adjusts the direction of the optical axis of a vehicle's headlights. The light control device includes an optical axis angle changing means, a taillight detection means, an angle calculation means, and an angle command means.

The optical axis angle changing means changes the direction of the optical axis of the headlight to a predetermined angle that is set in response to an external command.
The tail light detection means acquires an image from a camera that captures an image of the area ahead of the vehicle, and detects tail lights of other vehicles from the captured image.

The angle calculation means sets an illumination target based on the position of the detected taillight in the captured image, and calculates the angle at which the headlight's optical axis is directed toward the illumination target.

The angle command means changes the direction of the optical axis of the headlight to the angle calculated by the angle calculation means.
According to this light control device, when a preceding vehicle is traveling in the same direction as the subject vehicle, the optical axis of the headlights is changed to an illumination target set based on the position of the taillights of the preceding vehicle in the captured image, thereby preventing the driver of the preceding vehicle from being dazzled and preventing the creation of an area between the subject vehicle and the preceding vehicle that is not illuminated by the headlights.

JP 2009-67084 A

In the case of the device described in Patent Document 1, when the taillights of a preceding vehicle are detected in the captured image acquired by the camera, the optical axis of the headlights is lowered. Therefore, even if there is little possibility that the light of the headlights of the own vehicle will dazzle the driver of the preceding vehicle, such as when the preceding vehicle is a large vehicle and the own vehicle is a small vehicle, the optical axis is lowered, which is likely to cause discomfort to the driver of the own vehicle.

The vehicle headlamp control device for solving the above problem is a vehicle headlamp control device that controls the vertical tilt adjustment of the optical axis of the vehicle's headlamp, and includes a detection unit that detects the vehicle distance between the vehicle and a preceding vehicle traveling ahead of the vehicle just before the vehicle, and the rear vision device of the preceding vehicle, and a control unit that lowers the optical axis so that the extension line is below the rear vision device when the vehicle distance is within the light distribution range of the headlamp and the rear vision device is below both a reference line that extends along the fore-and-aft direction of the vehicle through the headlamp and an extension line of the optical axis of the headlamp.

According to this configuration, when the distance between the preceding vehicle and the vehicle itself is within the light distribution range of the vehicle's headlights and the rearview device of the preceding vehicle is below both a reference line that passes through the headlights and extends in the fore-and-aft direction of the vehicle and an extension of the optical axis of the headlights, the optical axis is lowered. As a result, the extension is below the rearview device such as the room mirror or side mirror, so that the light from the vehicle's headlights is prevented from entering the rearview device. This makes it possible to prevent dazzling the driver of the preceding vehicle.

On the other hand, when the vehicle distance is not within the light distribution range of the headlights, when the rearview device is above the reference line, or when the rearview device is above the extension of the headlight optical axis, the optical axis is not lowered. This makes it possible to prevent the optical axis from being lowered when there is little possibility that the driver of the preceding vehicle will be dazzled by the light from the headlights of the vehicle in question.

Therefore, dazzling of the driver of the preceding vehicle can be appropriately suppressed.
In the above vehicle headlamp control device, it is preferable that, when lowering the optical axis so that the extension line is below the rear visibility device, the control unit lowers the optical axis in a stepwise manner.

According to this configuration, when the optical axis is lowered so that the extension line is below the rear vision device, the optical axis is lowered in stages. This prevents the optical axis from being lowered significantly all at once, causing discomfort to the driver of the vehicle.

In the vehicle headlamp control device, the detection unit detects the height of the roof of the preceding vehicle, and the control unit preferably prohibits the adjustment of the vertical tilt of the optical axis when the height of the roof is higher than the height of the headlamp.

If the roof height of the preceding vehicle is higher than the height of the headlights of the vehicle itself, the rear vision device is generally installed at a higher position according to the height of the roof, and therefore will be above the reference line.

In this regard, with the above configuration, when the roof height of the preceding vehicle is higher than the height of the headlights of the vehicle itself, the adjustment of the vertical tilt of the optical axis is prohibited, so that the increase in the control load associated with the adjustment of the vertical tilt of the optical axis can be suppressed.

In the above vehicle headlamp control device, it is preferable that the control unit derives a light axis angle, which is the angle between the reference line and the light axis of the headlamp, and derives a device angle, which is the angle between the reference line and a virtual line connecting the headlamp and the rear vision device, and lowers the light axis so that the light axis angle is larger than the device angle when the inter-vehicle distance is within the light distribution range and the light axis angle is smaller than the device angle.

According to this configuration, it is possible to easily determine whether or not the rear vision device is below both the reference line and the extension line based on a comparison between the optical axis angle and the device angle.
In the above vehicle headlamp control device, it is preferable that the detection unit includes at least one of a camera that captures an image of the area ahead of the vehicle and a radar that measures the area ahead of the vehicle.

With this configuration, the distance between the vehicle ahead and the vehicle itself can be detected by a radar such as a millimeter wave radar installed in the vehicle. In addition, the rear view device of the vehicle ahead can be detected based on an image captured by a camera installed in the vehicle. Therefore, there is no need to provide a dedicated detection unit.

In the vehicle headlamp control device, it is preferable that the control unit has a memory that can be rewritten via wired or wireless communication, and performs the tilt adjustment control based on a program stored in the memory.

According to this configuration, in a vehicle equipped with headlights that can be adjusted in vertical inclination and at least one of a camera that captures an image ahead of the vehicle and a radar that measures the area ahead of the vehicle, the effects of the invention described above can be easily achieved by rewriting the program stored in the memory of the control unit.

The present invention can appropriately prevent dazzling the driver of the preceding vehicle.

FIG. 1 is a side view showing a front part of a vehicle, focusing on a headlamp, of a vehicle headlamp control device according to an embodiment. FIG. 2 is a partially enlarged view showing a main part of FIG. FIG. 3 is a block diagram showing an electrical configuration of the vehicle headlamp control device according to the embodiment. FIG. 4 is a flowchart showing a processing procedure for controlling the optical axis adjustment of the headlights according to the embodiment. FIG. 5 is a side view showing the positional relationship between the host vehicle and a leading vehicle in the embodiment. FIG. 6 is a schematic diagram showing the relationship between various distances and the optical axis angle and the device angle. FIG. 7 is a schematic diagram for explaining the operation of the embodiment. FIG. 8 is a schematic diagram for explaining the operation of the embodiment.

Hereinafter, an embodiment of a vehicle headlamp control device (hereinafter, referred to as a control device 60) will be described with reference to FIGS. 1 to 8. FIG.
In the following description, the fore-and-aft direction of the vehicle 70 is referred to as the fore-and-aft direction L, and the up-and-down direction of the vehicle 70 when the vehicle 70 is positioned on a horizontal plane is referred to as the up-and-down direction Z.

In addition, the front and rear sides in the front-to-rear direction L will be referred to simply as the "front" and "rear", respectively, and the upper and lower sides in the vertical direction Z will be referred to simply as the "upper" and "lower", respectively.

<Headlamp 10>
As shown in Fig. 1, a headlamp 10 is provided at the front of a vehicle 70. The headlamp 10 is arranged in pair at a distance from each other in the vehicle width direction (the direction perpendicular to the plane of Fig. 1).

As shown in FIG. 2 , the headlamp 10 has a housing 11 and a cover 14 .
The housing 11 has a peripheral wall 12 that defines an opening 12a that opens forward, and an opposing wall 13 that is located rearward of the opening 12a and faces the opening 12a in the front-rear direction L. The housing 11 is fixed to a frame of a vehicle body (not shown). The housing 11 is made of, for example, hard resin.

The cover 14 is transparent to visible light. The cover 14 is attached to the periphery of the opening 12a in the peripheral wall 12 so as to cover the opening 12a from the front. The cover 14 is made of, for example, a hard resin.

A light emitting unit 20 is provided inside the housing 11 via a drive unit 30 .
The light emitting section 20 includes a light source 21 and a reflecting mirror 22 .
The reflecting mirror 22 has a bowl shape that opens forward. The light source 21 is attached to the bottom of the reflecting mirror 22. The reflecting mirror 22 reflects the light emitted from the light source 21 forward. Therefore, the light emitting unit 20 has an optical axis A that extends in the front-rear direction L.

The drive unit 30 includes a motor 31 , a conversion mechanism 32 , a lower support unit 33 , and an upper support unit 36 .
The motor 31 is provided on the rear side of the opposing wall 13. The motor 31 has an output shaft 31a extending in the front-rear direction L. The output shaft 31a extends through the opposing wall 13 into the inside of the housing 11.

A lower support portion 33 is connected to the output shaft 31 a via a conversion mechanism 32 .
The lower support portion 33 is connected to the conversion mechanism 32 and includes a lower shaft portion 34 extending in the front-rear direction L, and a receiving portion 35 connected to the rear surface of the reflecting mirror 22. A spherical portion 34a is provided at the front end of the lower shaft portion 34. The receiving portion 35 has a concave spherical support surface that supports the spherical portion 34a so that it can roll freely.

The upper support portion 36 has a front shaft portion 37 extending rearward from the reflector 22, and a rear shaft portion 38 that is connected to the front surface of the opposing wall 13 and extends in the front-to-rear direction L. A spherical portion 37a is provided at the rear end of the front shaft portion 37. A bearing 38a is provided at the front end of the rear shaft portion 38. The bearing 38a has a concave spherical support surface that supports the spherical portion 37a so that it can roll freely.

The conversion mechanism 32 has a known configuration for converting the rotational motion of the output shaft 31 a into linear motion in the front-rear direction L of the lower shaft portion 34 .
When the output shaft 31a is rotated in the forward direction, the lower shaft portion 34 is pulled rearward via the conversion mechanism 32. At this time, the lower portion of the reflecting mirror 22 is pulled rearward via the receiving portion 35, so that the optical axis A is lowered.

When the output shaft 31a is rotated in the reverse direction, the lower shaft portion 34 is pushed forward via the conversion mechanism 32. At this time, the lower portion of the reflector 22 is pushed forward via the receiving portion 35, thereby raising the optical axis A.

The motor 31 is provided with a rotation angle sensor 39 for detecting the rotation angle θa of the output shaft 31a. The rotation angle sensor 39 has a known configuration for detecting the rotation angle θa of the output shaft 31a, such as a magnetic sensor.

As shown in FIG. 3 , the control device 60 includes a detection unit 40 and a control unit 50 , both of which are provided in a vehicle 70 .
<Detection Unit 40>
The detection unit 40 detects a distance D1 between the vehicle 70 and a leading vehicle 80 traveling ahead of the vehicle 70, and a rearview device 81 of the leading vehicle 80. In this embodiment, the detection unit 40 detects a rearview mirror 82 as the rearview device 81.

The detection unit 40 includes a radar 41 , a camera 42 , and an image processing unit 43 .
The radar 41 measures the area ahead of the vehicle 70. More specifically, the radar 41 detects the inter-vehicle distance D1 between the leading vehicle 80 and the vehicle 70. The radar 41 in this embodiment is, for example, a well-known millimeter wave radar. The radar 41 is provided at approximately the same position as the light emitting unit 20 of the headlamp 10 in the front-rear direction L.

The camera 42 captures an image of the area ahead of the vehicle 70. The camera 42 is disposed, for example, in the passenger compartment of the vehicle 70, adjacent to and behind an upper portion of the windshield.
The image processing unit 43 processes the image captured by the camera 42 to detect the rearview visual device 81 of the leading vehicle 80 traveling in front of the vehicle 70, and detects the height of the rearview visual device 81 from the road surface G. The radar 41 and the camera 42 are electrically connected to the image processing unit 43.

The image processing unit 43 processes the image captured by the camera 42 to identify the roof 86, the rear vision device 81, and the license plate 85 of the leading vehicle 80 (see FIG. 5).
The image processing unit 43 derives the height H2 of the roof 86 from the road surface G by multiplying the height of the roof 86 from the road surface G in the captured image by a predetermined scale ratio that is set according to the inter-vehicle distance D1.

The image processing unit 43 derives the height H3 of the rearview device 81 from the road surface G by multiplying the height of the rearview device 81 from the road surface G in the captured image by a predetermined scale ratio that is set according to the vehicle distance D1. In more detail, the image processing unit 43 derives the height H3 of the lowest point of the rearview device 81 from the road surface G.

The image processing unit 43 derives the height H4 of the license plate 85 from the road surface G by multiplying the height of the license plate 85 from the road surface G in the captured image by a predetermined scale ratio that is set according to the above-mentioned inter-vehicle distance D1. In detail, the image processing unit 43 derives the height H4 of the lowest point of the license plate 85 from the road surface G.

The image processing unit 43 derives the distance D2 between the vehicle 70 and the rearview device 81 by adding a predetermined value Df to the vehicle distance D1. Here, the predetermined value Df is the distance between the rear end of a typical vehicle and the rearview mirror.

<Control Unit 50>
3, the control unit 50 performs control to adjust the up and down tilt of the optical axis A of the headlamp 10 (hereinafter, optical axis adjustment control) based on a signal output from the detection unit 40. In addition to the detection unit 40 (radar 41 and image processing unit 43), the control unit 50 is electrically connected to the motor 31 and the rotation angle sensor 39.

The control unit 50 includes a rewritable memory 51. The memory 51 stores a program for executing the optical axis adjustment control.
The control unit 50 executes the optical axis adjustment control based on a program stored in the memory 51 .

The control unit 50 is configured to be able to communicate with a control device outside the vehicle 70 via wired or wireless communication.
Here, an imaginary line passing through the headlamp 10 and extending in the fore-and-aft direction L is defined as a reference line L1, and an imaginary line extending from the optical axis A of the headlamp 10 is defined as an extension line L2.

When the vehicle distance D1 is within the light distribution range S of the headlamp 10 and the rearward visibility device 81 is below both the reference line L1 and the extension line L2, the control unit 50 lowers the optical axis A so that the extension line L2 is below the rearward visibility device 81.

In detail, the control unit 50 derives the light distribution range S by referring to a map that defines the relationship between the amount of light of the headlight 10, the vertical inclination of the optical axis A, and the light distribution range S of the headlight 10. The map is pre-stored in the memory 51.

In detail, the control unit 50 derives the optical axis angle θ1, which is the angle between the reference line L1 and the optical axis A of the headlamp 10. The control unit 50 derives the device angle θ2, which is the angle between the reference line L1 and the virtual line L3 connecting the headlamp 10 and the rear vision device 81. When the inter-vehicle distance D1 is within the light distribution range S and the optical axis angle θ1 is smaller than the device angle θ2, the control unit 50 lowers the optical axis A so that the optical axis angle θ1 is larger than the device angle θ2. The control unit 50 lowers the optical axis A until the optical axis angle θ1 becomes the lower limit angle θ3. When lowering the optical axis A, the control unit 50 lowers the optical axis A in stages.

Here, the control unit 50 derives the optical axis angle θ1 based on the rotation angle θa detected by the rotation angle sensor 39 .
The control unit 50 derives the device angle θ2 as follows.

As shown in FIG. 6, the device angle θ2 is derived from the distance D2 between the vehicle 70 and the rearview device 81 and the distance ΔH1 between the reference line L1 in the vertical direction Z and the rearview device 81 (in this case, the rearview mirror 82).

The control unit 50 derives the distance ΔH1, which is the difference between the height H1 of the headlamp 10 from the road surface G and the height H3 of the rear vision device 81.
In addition, the control unit 50 derives the difference between the height H1 of the headlamp 10 and the height H4 of the license plate 85, i.e., the distance ΔH2 between the headlamp 10 and the license plate 85 in the vertical direction Z.

The control unit 50 derives the lower limit angle θ3, which is the angle between the virtual line L4 connecting the headlamp 10 and the license plate 85 and the reference line L1, from the inter-vehicle distance D1 and the above-mentioned distance ΔH2.
Next, the processing procedure of the optical axis adjustment control will be described with reference to the flowchart of Fig. 4. This series of processing is executed by the control unit 50 when the inter-vehicle distance D1 is within the light distribution range S of the headlamp 10 while the vehicle 70 is traveling.

In this series of processes, first, the control unit 50 determines whether or not the height H2 of the roof 86 of the leading vehicle 80 is lower than the height H1 of the headlights 10 (step S1).
If it is determined that the height H2 of the roof 86 is not lower than the height H1 of the headlamp 10 (step S1: NO), this series of processes ends without adjusting the vertical tilt of the optical axis A. That is, in this case, the control unit 50 prohibits the adjustment of the vertical tilt of the optical axis A.

On the other hand, if it is determined that the height H2 of the roof 86 is lower than the height H1 of the headlamp 10 (step S1: "YES"), the control unit 50 derives the optical axis angle θ1, the device angle θ2, and the lower limit angle θ3 (step S2).

Next, the control unit 50 determines whether the optical axis angle θ1 is smaller than the device angle θ2 (step S3).
If it is determined that the optical axis angle θ1 is not smaller than the device angle θ2 (step S3: NO), the vertical inclination of the optical axis A is not adjusted and this series of processes is terminated.

On the other hand, if it is determined that the optical axis angle θ1 is smaller than the device angle θ2 (step S3: "YES"), the control unit 50 then determines whether the lower limit angle θ3 is smaller than the legal lower limit angle θr, which is the lower limit of the optical axis angle set by law (step S4).

Here, if it is determined that the lower limit angle θ3 is not smaller than the legal lower limit angle θr (step 4: "NO"), the control unit 50 intermittently rotates the motor 31 in the forward direction to gradually lower the optical axis A until the optical axis angle θ1 becomes the legal lower limit angle θr (step S5). Then, the control unit 50 ends this series of processes.

On the other hand, if it is determined that the lower limit angle θ3 is smaller than the legal lower limit angle θr (step 4: "YES"), the control unit 50 intermittently rotates the motor 31 in the forward direction to gradually lower the optical axis A until the optical axis angle θ1 becomes the lower limit angle θ3 (step S6). Then, the control unit 50 ends this series of processes.

When the vehicle distance D1 is no longer within the light distribution range S of the headlamp 10, the control unit 50 reverses the rotation of the motor 31 so that the optical axis angle θ1 becomes the optical axis angle θ1 before the optical axis adjustment control was started.

Next, the operation of this embodiment will be described.
As shown in FIG. 7, the inter-vehicle distance D1 between the preceding vehicle 80 and the vehicle 70 is within the light distribution range S of the headlight 10 of the vehicle 70.

In addition, as shown by the two-dot chain line in FIG. 8, the bottom end of the rear vision device 81 (in this embodiment, the rearview mirror 82) of the preceding vehicle 80 is below both the reference line L1 and the extension line L2 of the optical axis A of the headlamp 10.

At this time, as shown by the solid line in FIG. 8, the optical axis A is lowered so that the extension line L2 is lower than the rear viewing device 81.
As a result, the extension line L2 is located below the rearview visual device 81, so that the light of the headlight 10 of the vehicle 70 is prevented from entering the rearview visual device 81. Therefore, dazzling of the driver of the leading vehicle 80 can be prevented.

On the other hand, although not shown, when the inter-vehicle distance D1 is not within the light distribution range S of the headlight 10, the optical axis A is not lowered. In addition, when the rearward vision device 81 is above the reference line L1 or when the rearward vision device 81 is above the extension line L2 of the optical axis A of the headlight 10, the optical axis A is not lowered. For this reason, it is possible to prevent the optical axis A from being lowered when there is little possibility that the light of the headlight 10 of the vehicle 70 will dazzle the driver of the preceding vehicle 80.

Next, the effects of this embodiment will be described.
(1) When the inter-vehicle distance D1 is within the light distribution range S of the headlight 10 and the rearview device 81 is below both the reference straight line L1 and the extension line L2 of the optical axis A of the headlight 10, the control unit 50 performs control to adjust the up and down tilt of the optical axis A. The control unit 50 lowers the optical axis A so that the extension line L2 is below the rearview device 81.

With this configuration, the above-mentioned effect is achieved, and dazzling of the driver of the leading vehicle 80 can be appropriately suppressed.
(2) When lowering the optical axis A so that the extension line L2 is below the rear viewing device 81, the control unit 50 lowers the optical axis A in stages.

With this configuration, when the optical axis A is lowered so that the extension line L2 is below the rear vision device 81, the optical axis A is lowered in stages. This prevents the optical axis A from being lowered significantly all at once, causing the driver of the vehicle 70 to feel uncomfortable.

(3) The detection unit 40 detects the height H2 of the roof 86 of the preceding vehicle 80. When the height H2 of the roof 86 is higher than the height H1 of the headlamp 10, the control unit 50 prohibits the adjustment of the vertical inclination of the optical axis A.

When the height H2 of the roof 86 of the preceding vehicle 80 is higher than the height H1 of the headlights 10 of the vehicle 70, the rear vision device 81 is generally installed at a higher position according to the height H2 of the roof 86, and is therefore above the reference line L1.

In this regard, according to the above configuration, when the height H2 of the roof 86 of the preceding vehicle 80 is higher than the height H1 of the headlamp 10 of the vehicle 70, the tilt adjustment of the optical axis A is prohibited, so that the increase in the control load associated with performing the tilt adjustment can be suppressed.

(4) When the vehicle distance D1 is within the light distribution range S and the optical axis angle θ1 is smaller than the device angle θ2, the control unit 50 lowers the optical axis A so that the optical axis angle θ1 is larger than the device angle θ2.

With this configuration, it is easy to determine whether the rearview device 81 is below both the reference line L1 and the extension line L2 based on a comparison between the optical axis angle θ1 and the device angle θ2.

(5) The detection unit 40 includes a camera 42 that captures an image of the area ahead of the vehicle 70 and a radar 41 that measures the area ahead of the vehicle 70 .
According to this configuration, the radar 41, such as a millimeter wave radar, provided on the vehicle 70 can detect the inter-vehicle distance D1 between the preceding vehicle 80 and the vehicle 70. Also, the rear vision device 81 of the preceding vehicle 80 can be detected based on an image captured by the camera 42 provided on the vehicle 70. Therefore, there is no need to provide a dedicated detection unit.

(6) The control unit 50 includes a memory 51 that can be rewritten via wired or wireless communication, and performs tilt adjustment control based on a program stored in the memory 51.
According to this configuration, in a vehicle 70 equipped with headlights 10 whose inclination can be adjusted up and down, a camera 42 that captures an image ahead of the vehicle 70, and a radar 41 that measures the area ahead of the vehicle 70, it is possible to rewrite the program stored in memory 51 of the control unit 50. Moreover, by rewriting the program stored in memory 51, the control unit 50 can easily achieve the effects of the invention described above.

<Modification>
This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

The memory 51 that stores the program for controlling the optical axis adjustment may be non-rewritable.
The detection unit 40 detects the vehicle distance D1 between the leading vehicle 80 and the vehicle 70 and the rear vision device 81 by using the camera 42 and the radar 41, but is not limited to this. For example, in the vehicle 70 equipped with LiDAR (Light Detection and Ranging), the vehicle distance D1 and the rear vision device 81 may be detected by using the LiDAR. The LiDAR measures scattered light in response to a laser irradiation that emits a pulsed light, and analyzes the distance to a distant object and the properties of the object.

- The control unit 50 performs the optical axis adjustment control by comparing the optical axis angle θ1 and the device angle θ2, but this is not limited to the above. In other words, the control unit 50 can adopt other modes as long as it can determine that the rear vision device 81 of the leading vehicle 80 is below both the reference line L1 and the extension line L2.

The detection unit 40 does not have to detect the height H2 of the roof 86 of the leading vehicle 80.
In the above embodiment, the control unit 50 lowers the optical axis A stepwise by lowering the optical axis A by a predetermined angle at a time, but this is not limited to the above. For example, when multiple rearview devices such as a room mirror and a side mirror are used, the device angles of the multiple rearview devices may be derived, and the optical axis A may be sequentially lowered in order from the largest device angle so that the optical axis angle θ1 is larger than the device angle.

- In the above embodiment, the detection unit 40 detects the rearview mirror 82 as the rearview device 81, but this is not limited thereto. The detection unit 40 may also detect a side mirror as the rearview device 81. Furthermore, for a preceding vehicle equipped with a camera for rearview, the detection unit 40 may detect the camera as the rearview device.

LIST OF SYMBOLS 10...Headlamp 11...Housing 12...Surrounding wall 12a...Opening 13...Opposite wall 14...Cover 20...Light emitting portion 21...Light source 22...Reflector 30...Drive portion 31...Motor 31a...Output shaft 32...Conversion mechanism 33...Lower support portion 34...Lower shaft portion 34a...Spherical portion 35...Receiving portion 36...Upper support portion 37...Front shaft portion 37a...Spherical portion 38...Rear shaft portion 38a...Bearing 39...Rotation angle sensor 40...Detection portion 41...Radar 42...Camera 43...Image processing portion 50...Control portion 51...Memory 60...Control device 70...Vehicle 80...Preceding vehicle 81...Rearview visibility device 82...Room mirror (rearview visibility device)
85...Number plate 86...Roof

Claims (6)

A vehicle headlamp control device that controls the vertical tilt adjustment of the optical axis of a vehicle headlamp,
a detection unit that detects a distance between the vehicle and a preceding vehicle traveling ahead of the vehicle and a rear view device of the preceding vehicle;
and a control unit that lowers the optical axis so that the extension line of the optical axis of the headlight is lower than the rearview device when the inter-vehicle distance is within a light distribution range of the headlight and the rearview device is below both a reference line that passes through the headlight and extends in the front-rear direction of the vehicle and an extension line of the optical axis of the headlight.
Vehicle headlamp control device. When lowering the optical axis so that the extension line is lower than the rear visual confirmation device, the control unit lowers the optical axis in a stepwise manner.
The vehicle headlamp control device according to claim 1 . The detection unit detects a height of a roof of the preceding vehicle,
The control unit prohibits adjustment of the vertical inclination of the optical axis when the height of the roof is higher than the height of the headlight.
The vehicle headlamp control device according to claim 1 or 2. the control unit derives a light axis angle which is an angle between the reference line and the light axis of the headlight, and derives a device angle which is an angle between the reference line and a virtual line connecting the headlight and the rear vision device, and when the inter-vehicle distance is within the light distribution range and the light axis angle is smaller than the device angle, lowers the light axis so that the light axis angle is larger than the device angle.
The vehicle headlamp control device according to claim 1 . The detection unit includes at least one of a camera that captures an image of the front of the vehicle and a radar that measures the front of the vehicle.
The vehicle headlamp control device according to claim 1 . The control unit includes a memory that can be rewritten by wired or wireless communication,
performing the tilt adjustment control based on a program stored in the memory;
The vehicle headlamp control device according to claim 5.

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