CN115038614A

CN115038614A - Vehicle headlamp

Info

Publication number: CN115038614A
Application number: CN202180011897.6A
Authority: CN
Inventors: 田中秀忠
Original assignee: Koito Manufacturing Co Ltd
Current assignee: Koito Manufacturing Co Ltd
Priority date: 2020-01-31
Filing date: 2021-01-29
Publication date: 2022-09-09
Also published as: WO2021153775A1; JPWO2021153775A1

Abstract

A vehicle headlamp (10) is provided with a pair of lamps (20) arranged on the left and right of the front part of a vehicle (100), and a control unit (40) for controlling the pair of lamps (20). The control unit (40) controls the lamp (20a) and the lamp (20b) such that, when a signal indicating that the retroreflective article (401) located in front of the vehicle is detected is input from the detection device (50), a first light amount of first light emitted from the lamp (20a) located on the retroreflective article (401) side toward the retroreflective article (401) is smaller than a second light amount of second light emitted from the lamp (20b) located on the opposite side of the retroreflective article (401) side toward the retroreflective article (401).

Description

Vehicle headlamp

Technical Field

The present invention relates to a vehicle headlamp.

Background

Conventionally, there have been known vehicle headlamp systems that detect a light-emitting object such as a preceding vehicle that emits light, and a retro-reflector such as a road sign that does not emit light and reflects light again at a predetermined spread angle. Such a vehicle headlamp system is disclosed in patent document 1. The vehicle headlamp system disclosed in patent document 1 includes: a headlamp that alternately repeats irradiation and non-irradiation of light; and an imaging unit that images the front of the vehicle at the time of irradiation and at the time of non-irradiation, respectively, and generates an image at the time of irradiation and an image at the time of non-irradiation. The vehicle headlamp system further includes a detection unit that determines a high luminance portion in the non-irradiation image as a light-emitting object and determines a high luminance portion in the irradiation image but not in the non-irradiation image as a retro-reflector.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-110999

Disclosure of Invention

Problems to be solved by the invention

However, when light from headlamps arranged in the left-right direction in front of the host vehicle is irradiated onto the retroreflective object, part of the light is emitted from the retroreflective object to the host vehicle as reflected light, and may cause glare to the driver of the host vehicle. This may reduce the visibility of the driver.

Accordingly, an object of the present invention is to provide a vehicle headlamp capable of suppressing a reduction in visibility of a driver.

Means for solving the problems

In order to solve the above-described problems, a vehicle headlamp according to the present invention includes a pair of lamps disposed on the left and right sides of a front portion of a vehicle, and a control unit that controls the pair of lamps, and when a signal indicating that a retro-reflecting object located in front of the vehicle is detected is input from a detection device, the control unit controls the one lamp and the other lamp such that the amount of light emitted from one of the pair of lamps located on the side of the retro-reflecting object toward at least the retro-reflecting object is smaller than the amount of light emitted from the other of the pair of lamps located on the side opposite to the retro-reflecting object toward at least the retro-reflecting object.

In the case of the retro-reflecting object reflecting light, the smaller the amount of deviation of the lamp in the left-right direction of the vehicle with respect to the retro-reflecting object, the stronger the intensity of the reflected light from the retro-reflecting object toward the vehicle tends to be. In this vehicle headlamp, one lamp is located on the regressive-reflector side, and the other lamp is located on the opposite side of the regressive-reflector side. Therefore, the amount of offset of one lamp in the left-right direction of the vehicle with respect to the retro-reflective object is smaller than the amount of offset of the other lamp in the left-right direction of the vehicle with respect to the retro-reflective object. In this vehicle headlamp, when a regressive object is detected, the amount of light directed from one lamp located on the regressive object side toward the regressive object is smaller than the amount of light directed from the other lamp located on the opposite side of the regressive object side toward the regressive object. When the light amount of the light from one lamp is smaller than the light amount of the light from the other lamp, the intensity of the reflected light can be suppressed, and glare to the driver of the host vehicle can be suppressed even if the reflected light travels toward the host vehicle, as compared with a case where the light amount of the light from one lamp is not smaller than the light amount of the light from the other lamp. Therefore, according to the vehicle headlamp, the deterioration of the visibility of the driver can be suppressed.

In the vehicle headlamp, it is preferable that the detection device further includes a determination unit that determines whether or not the retro-reflecting object satisfies a predetermined requirement that a light amount of the reflected light from the retro-reflecting object is equal to or greater than a predetermined value when the signal indicating the state of the retro-reflecting object is input from the detection device, and that the control unit controls the one lamp and the other lamp so that a sum of the light amount of the light from the one lamp and the light amount of the other lamp is smaller in a case where the determination unit determines that the retro-reflecting object satisfies the predetermined requirement than in a case where the determination unit determines that the retro-reflecting object does not satisfy the predetermined requirement.

According to this vehicle headlamp, the intensity of the reflected light can be further suppressed in a state where the retro-reflecting object satisfies the predetermined requirement, as compared with a state where the retro-reflecting object does not satisfy the predetermined requirement. Therefore, according to the vehicle headlamp, the degradation of the visibility of the driver can be further suppressed.

In addition, it is preferable that, when the determination unit determines that the retroreflective article satisfies the predetermined requirement, the control unit controls the one lamp and the other lamp so that the amount of light of the light from the one lamp and the amount of light of the light from the other lamp are reduced, respectively, as compared to when the determination unit determines that the retroreflective article does not satisfy the predetermined requirement.

According to this vehicle headlamp, in a state where the retro-reflector satisfies the predetermined requirement, the irradiation of light onto the retro-reflector is suppressed, and the intensity of reflected light can be further suppressed, as compared with a state where the retro-reflector does not satisfy the predetermined requirement. Therefore, according to the vehicle headlamp, the deterioration of the visibility of the driver can be further suppressed.

In addition, when the determination unit determines that the retroreflective article satisfies the predetermined requirement, the control unit may control the one lamp and the other lamp such that the amount of light of the light from the one lamp is reduced and the amount of light of the light from the other lamp is increased, as compared to a case where the determination unit determines that the retroreflective article does not satisfy the predetermined requirement.

In this case, the retroreflective article is brighter by the light as compared with the case where the amount of light from the other lamp is not increased, and therefore, the visibility of the retroreflective article by the driver can be ensured.

In addition, it is preferable that the control unit controls the pair of lamps so that a difference between a light amount of light emitted from the pair of lamps toward the retroreflective article and a light amount of light emitted from the pair of lamps toward the front of the vehicle excluding the retroreflective article is converged within a predetermined range when the determination unit determines that the retroreflective article satisfies the predetermined requirement.

When a target object such as a pedestrian is located in front of a vehicle other than the retro-reflector, the above difference is converged to a predetermined range, thereby suppressing a relative difference between the brightness of the retro-reflector and the brightness of the target object. Therefore, according to the vehicle headlamp, the reduction in the visibility of the object by the driver can be suppressed.

In addition, it is preferable that the state satisfying the predetermined requirement is a state in which a distance between the retroreflective article and the vehicle is smaller than a predetermined distance.

When the distance between the retroreflective object and the vehicle is less than the predetermined distance in a state where the light quantity of the light emitted from the pair of lamps is not changed, the intensity of the light reflected from the retroreflective object to the host vehicle tends to be stronger than in a state where the distance is equal to or greater than the predetermined distance. In the case where the distance is smaller than the predetermined distance, the control unit controls the pair of lamps so that the first light amount is smaller than the second light amount, as described above. Therefore, in a state where the distance between the retroreflective object and the vehicle is less than the predetermined distance, the intensity of the reflected light traveling from the retroreflective object to the host vehicle can be suppressed, the application of glare can be suppressed, and the degradation of the visibility of the driver can be suppressed, as compared with a state where the distance is equal to or greater than the predetermined distance.

Alternatively, it is preferable that the state satisfying the predetermined requirement is a state in which the apparent size of the retroreflective article is equal to or larger than a predetermined value.

Even if the distance between the retro-reflector and the vehicle is equal to or greater than the predetermined distance, when the apparent size of the retro-reflector is equal to or greater than the predetermined value, part of the light from the vehicle may be directed as reflected light from the retro-reflector toward the vehicle, and glare may be caused to the driver of the vehicle, as compared with the case where the retro-reflector is smaller than the predetermined size. As described above, when the state satisfying the predetermined requirement is a state in which the apparent size of the retroreflective article is equal to or larger than the predetermined value, the control unit controls the pair of lamps so that the first light amount is smaller than the second light amount. Therefore, even when the distance between the retroreflective article and the vehicle is equal to or greater than the predetermined distance and the apparent size of the retroreflective article is equal to or greater than the predetermined value, the intensity of the reflected light traveling from the retroreflective article to the host vehicle can be suppressed, the application of glare can be suppressed, and the reduction in the visibility of the driver can be suppressed.

Effects of the invention

According to the present invention, it is possible to provide a vehicle headlamp capable of suppressing a reduction in visibility of a driver.

Drawings

Fig. 1 is a plan view conceptually showing a vehicle.

Fig. 2 is a cross-sectional view schematically showing a vertical direction of one lamp shown in fig. 1.

Fig. 3 is a flowchart illustrating an operation of the vehicle headlamp.

Fig. 4 is a diagram illustrating a light distribution pattern of high beam in a case where the retroreflective article does not satisfy a predetermined requirement.

Fig. 5 is a diagram showing a light distribution pattern of high beam when the retroreflective article satisfies a predetermined requirement.

Fig. 6 is a diagram showing a light distribution pattern formed by the first light when the retroreflective article satisfies a predetermined requirement.

Fig. 7 is a diagram illustrating a light distribution pattern formed by the second light when the retroreflective article satisfies a predetermined condition.

Detailed Description

Hereinafter, preferred embodiments of the vehicle headlamp according to the present invention will be described in detail with reference to the accompanying drawings. The following exemplary embodiments are for easy understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved without departing from the gist thereof. In addition, the present invention can also be combined with the components in the embodiments illustrated below as appropriate. In the drawings, some parts are exaggerated for convenience of understanding.

Fig. 1 is a plan view conceptually showing a vehicle 100. As shown in fig. 1, a vehicle 100 includes a vehicle headlamp 10 and a detection device 50.

The vehicle headlamp 10 of the present embodiment is an automotive headlamp. The vehicle headlamp 10 mainly includes a pair of lamps 20 arranged on the left and right of a front portion of the vehicle 100, a determination unit 35, a control unit 40, and a recording unit 70. In the present specification, "right" refers to the right side in the traveling direction of the vehicle 100, and "left" refers to the left side in the traveling direction of the vehicle 100.

The pair of lamps 20 of the present embodiment emit low beam or high beam forward of the vehicle 100. Hereinafter, description will be made of one lamp 20a of the pair of lamps 20 being located on the left side of the vehicle 100 and the other lamp 20b of the pair of lamps 20 being located on the right side of the vehicle 100. In this case, lamp 20a is located on the opposite side of lamp 20b with reference to a straight line passing through the center in the left-right direction of vehicle 100 and extending in the front-rear direction of vehicle 100. The lamp 20a has the same configuration as the lamp 20b, except that the shape is substantially symmetrical in the left-right direction. Therefore, the configuration of each of the

lamps

20a and 20b will be described below using the lamp 20 a.

Fig. 2 is a cross-sectional view schematically showing the lamp 20a in the vertical direction. As shown in fig. 2, the lamp 20a mainly includes a light source 21, a reflector 22, a reflector 23, a projection lens 24, and a light-absorbing plate 25. The light source 21, the reflector 22, the reflection device 23, the projection lens 24, and the light-absorbing plate 25 are housed in a housing, not shown.

The light source 21 emits light forward of the light source 21. The light source 21 is a light emitting element that emits light. Examples of the Light source 21 include an LED (Light Emitting Diode) that emits white Light.

The reflector 22 is a curved plate-like member. The reflector 22 has a reflecting surface 22r located on the inner surface of the curved reflector 22. The reflection surface 22r is curved so as to be concave toward the side opposite to the light source 21. Such a reflection surface 22r is, for example, a surface of a rotationally elliptic curved surface. The reflector 22 is disposed so that the reflecting surface 22r covers the light source 21 from the front side. The reflection surface 22r reflects light emitted from the light source 21 toward a reflection control surface 23r of the reflection device 23, which will be described later.

The reflector 23 is disposed above the light source 21 and behind the reflector 22. The reflecting Device 23 is a so-called DMD (Digital Mirror Device) having a reflecting control surface 23r that reflects light. The reflection control surface 23r is disposed so as to face the front side. The light emitted from the light source 21 and reflected by the reflection surface 22r of the reflector 22 is irradiated to the reflection control surface 23 r. The reflection control surface 23r is formed of reflection surfaces of a plurality of reflection elements arranged two-dimensionally. Each of the reflecting elements is individually supported on a substrate, not shown, so as to be tiltable. Each of the reflecting elements can be individually switched to a first tilted state in which light from the reflector 22 is reflected toward the projection lens 24 or a second tilted state in which light from the reflector 22 is reflected toward the light absorbing plate 25. By controlling the tilt state of each reflecting element, the reflecting device 23 can form a desired light distribution pattern or change the shape of the light distribution pattern by the light directed from the reflection control surface 23r toward the projection lens 24. Further, the reflector 23 can control the inclination state of each reflecting element over time, thereby making the intensity distribution of light of a desired light distribution pattern a desired intensity distribution.

The projection lens 24 is a lens that adjusts the divergence angle of incident light. The projection lens 24 is disposed further forward than the reflection device 23, and light directed from the reflection control surface 23r toward the projection lens 24 enters the projection lens 24, and the divergence angle of the light is adjusted by the projection lens 24. In the projection lens 24, the incident surface is curved in a convex shape toward the front, and the output surface is curved in a convex shape toward the front. The rear focal point of the projection lens 24 is located on or near the reflective control surface 23r of the reflector 23. A predetermined light whose divergence angle is adjusted by the projection lens 24 is emitted from the lamp 20a, and the predetermined light is irradiated to the front of the vehicle 100.

The light absorbing plate 25 is disposed forward and upward of the reflector 23. The light absorbing plate 25 is a plate-like member having light absorption properties, and converts most of the light incident on the light absorbing plate 25 into heat. When light directed from the reflection control surface 23r toward the light-absorbing plate 25 is incident to the light-absorbing plate 25, most of the light is converted into heat by the light-absorbing plate 25. Heat is released from the light absorbing plate 25 to the outside of the light absorbing plate 25. The light absorbing plate 25 is made of a metal such as aluminum, and a surface thereof is subjected to black alumite processing or the like.

Here, returning to fig. 1, the description of the vehicle 100 is continued.

When a control signal from a lamp switch, not shown, mounted on vehicle 100 is input to control unit 40, control unit 40 drives lamp 20a and lamp 20 b. When the control signal is not input to control unit 40, control unit 40 stops driving of lamp 20a and lamp 20 b. The control signal is a signal for instructing the start of light emission from the light sources 21 of the

lamps

20a and 20 b.

The Control unit 40 may be an Integrated Circuit such as a microcontroller, an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit), or an NC (digital Control) device. In the case of using an NC apparatus, the control unit 40 may or may not use a machine learning device.

The detection device 50 detects an object located in front of the vehicle 100. Examples of the object include a retroreflective object and an object other than the retroreflective object. The retroreflective article of the present embodiment is an article that does not emit light by itself but retroreflects light irradiated to the retroreflective article at a predetermined spread angle. Examples of such a retroreflective object include a road sign provided near a road. Examples of the object other than the retro-reflecting object include a vehicle such as a preceding vehicle or an oncoming vehicle, a pedestrian, and the like.

As a configuration of the detection device 50, the detection device 50 includes, for example, a camera, an image processing unit, and a detection unit, which are not shown. The camera is mounted on the front portion of the vehicle 100, and photographs the front of the vehicle 100. The captured image captured by the camera includes at least a part of the region irradiated with the light emitted from the pair of lamps 20. The image processing unit performs image processing on a captured image captured by the camera. When the retro-reflective object is detected, the detection unit outputs a signal indicating that the retro-reflective object is detected to the control unit 40 via the determination unit 35. The detection unit may output the signal directly to the control unit 40. The detection unit detects the state of the retroreflective article from the captured image subjected to the image processing by the image processing unit. Examples of the state of the retro-reflecting object include the presence of the retro-reflecting object, the presence position of the retro-reflecting object, and the proportion of the retro-reflecting object in the captured image. The configuration of the image processing unit and the configuration of the detection unit are, for example, the same as those of the control unit 40.

Next, an example of detecting the presence of a retro-reflective object from a captured image will be described. Note that, a case where the retroreflective object is a road sign will be described. The recording unit 70 records image data of each landmark in advance. When the object reflected in the captured image matches the road sign image data recorded in the recording unit 70, the detection unit detects the object as a retroreflective object. As another example of detection, the shape of a landmark is generally circular, rectangular, or triangular, and colors such as red, white, blue, yellow, black, and green are combined in the landmark. The detection unit may detect the object as the retro-reflective object as long as the object has any one of a circular shape, a rectangular shape, and a triangular shape in the captured image captured by the camera, and the color inside the outer shape of the object is a combination of the above colors. One example of the above two types of detection may be combined. In addition, in the case where the retroreflective article is a delineator (delimiteror), the reflected light from the delineator is orange, for example. The detection unit may detect the object as a retro-reflective object when light from the object reflected in the captured image captured by the camera is orange.

The detection device 50 outputs a signal indicating the state of the retroreflective article to the determination unit 35. Further, the detection device 50 outputs the captured image to the recording unit 70.

The determination unit 35 determines which of the right side and the left side of the vehicle the retroreflective article is located, based on a signal indicating the state of the retroreflective article from the detection device 50 that detects the retroreflective article located in front of the vehicle 100. For example, the determination unit 35 determines that the retro-reflective object is located on the left side of the vehicle 100 when the retro-reflective object is located in the region on the left side of the center in the captured image, and determines that the retro-reflective object is located on the right side of the vehicle 100 when the retro-reflective object is located in the region on the right side of the center in the captured image. A signal indicating the determination result is input to the control unit 40. The determination unit 35 determines whether or not the retroreflective object satisfies a predetermined condition that the amount of light reflected from the retroreflective object toward the host vehicle is equal to or greater than a predetermined value, based on a signal indicating the state of the retroreflective object from the detection device 50 that detects the retroreflective object located in front of the vehicle 100. The state satisfying the predetermined requirement is, for example, a state in which the distance between the retroreflective article and the vehicle 100 is smaller than a predetermined distance. The predetermined distance is, for example, 30 m. The numerical value of the distance may be recorded in the recording unit 70 as a threshold value, and may be changed according to the traveling condition of the vehicle 100 such as daytime and nighttime. For example, the determination unit 35 includes a calculation unit and a determination main body unit. The calculation unit calculates the distance between the retroreflective article and the vehicle 100 based on the above-described ratio in the state of the retroreflective article from the detection device 50. A signal indicating the calculated distance is output to the determination main body. The determination unit reads a predetermined distance as a threshold value from the recording unit 70, compares the calculated distance with the predetermined distance, and determines whether or not the calculated distance is greater than the predetermined distance. When the calculated distance is equal to or greater than the predetermined distance, the main body determines that the retroreflective article does not satisfy the predetermined requirement. When the calculated distance is less than the predetermined distance, the determination unit determines that the retroreflective article satisfies the predetermined requirement. The determination result of the main body portion is input to the control portion 40 as a signal together with a signal indicating the state of the retroreflective article, such as the position where the retroreflective article is present. The determination unit 35 has, for example, the same configuration as the control unit 40.

The recording unit 70 records the captured image output from the detection device 50 and the predetermined distance as the threshold value in the determination unit 35. Examples of the recording unit 70 include a semiconductor memory such as a ROM, and a magnetic disk.

Next, the operation of the vehicle headlamp 10 of the present embodiment will be described. Fig. 3 is a flowchart illustrating the operation of the vehicle headlamp 10 according to the present embodiment. As shown in fig. 3, the flowchart of the present embodiment includes steps S1 through S7.

Hereinafter, a case where the retro-reflecting object is located diagonally left forward of the vehicle 100 will be described.

Hereinafter, light emitted from the lamp 20a toward the front of the vehicle 100 including the retro-reflective object is referred to as first light, the light amount of the first light is referred to as first light amount, light emitted from the lamp 20b toward the front of the vehicle 100 including the retro-reflective object is referred to as second light, and the light amount of the second light is referred to as second light amount. In the initial state shown in fig. 3, the lamp switch is off.

(step S1)

In this step, the detection device 50 captures an image of the front of the vehicle 100 with a camera. When a retro-reflecting object located in front of the vehicle 100 is detected from the captured image, the detection device 50 outputs a signal indicating that the retro-reflecting object is detected to the control unit 40 via the determination unit 35, and outputs a signal indicating the state of the retro-reflecting object to the determination unit 35. When a signal is input, the process shifts to step S2.

(step S2)

In this step, if the lamp switch is kept off and a control signal from the lamp switch is not input to the control unit 40, the driving of the

lamps

20a and 20b is stopped, and the light is not emitted, and the process returns to step S1. In this step, if the lamp switch is turned on and a control signal from the lamp switch is input to the control unit 40, the

lamps

20a and 20b are driven, and the process proceeds to step S3.

(step S3)

In this step, the determination unit 35 determines which of the right side and the left side of the vehicle the retroreflective article is located based on the presence position of the retroreflective article in the signal indicating the state of the retroreflective article from the detection device 50. A signal indicating the determination result is output to the control unit 40. As described above, in the present embodiment, since the retroreflective article is positioned diagonally to the left in front of the vehicle 100, the lamp 20a is positioned on the retroreflective article side, and the lamp 20b is positioned on the opposite side of the retroreflective article side with respect to the lamp 20a in the left-right direction of the vehicle 100. In this case, the distance between the lamp 20a and the retro-reflector is shorter than the distance between the lamp 20b and the retro-reflector in the left-right direction of the vehicle 100. The determination unit 35 determines whether or not the retroreflective article satisfies a predetermined condition based on a signal indicating the state of the retroreflective article from the detection device 50. When the determination unit 35 determines that the retroreflective article does not satisfy the predetermined requirement, the process proceeds to step S4. When the determination unit 35 determines that the retroreflective article satisfies the predetermined requirement, the process proceeds to step S5. Hereinafter, a state in which the predetermined requirement is satisfied is described as an example of a state in which the distance between the retroreflective article and the vehicle 100 is smaller than a predetermined distance.

(step S4)

In this step, the distance between the retroreflective article and the vehicle 100 is equal to or greater than a predetermined distance, and the control unit 40 controls the driving of the lamp 20a on the retroreflective article side and the lamp 20b on the opposite side to the retroreflective article side as described below.

In step S4, for example, the control unit 40 drives the lamp 20a and the lamp 20b so that the first light amount is equal to the second light amount, the lamp 20a emits the first light toward the front of the vehicle 100, and the lamp 20b emits the second light toward the front of the vehicle 100. Fig. 4 is a diagram showing the light distribution pattern 200 of the high beam when the distance between the retroreflective article 401 and the vehicle 100 is equal to or greater than a predetermined distance. The light distribution pattern 200 is formed by combining a light distribution pattern, not shown, formed by the first light and a light distribution pattern, not shown, formed by the second light. In fig. 4, S represents a horizontal line, and a light distribution pattern formed on a vertical plane, for example, 25m away from the vehicle 100 is represented by a thick line. In fig. 4, for example, when the retroreflective article 401 is a road sign provided beside a road, the retroreflective article 401 is supported by a support 403 which is a metal pillar provided upright from the road. In this step, the control of the first light amount and the second light amount is not particularly limited, and the first light amount may be larger or smaller than the second light amount. When the first light and the second light are emitted, the process returns to step S1.

(step S5)

In this step, the distance between the retroreflective article 401 and the vehicle 100 is smaller than a predetermined distance, and the control unit 40 controls the driving of the lamp 20a on the retroreflective article side and the lamp 20b on the opposite side to the retroreflective article side as described below.

In step S5, control unit 40 drives lamp 20a and lamp 20b such that the first light amount is smaller than the second light amount, lamp 20a emits the first light toward the front of vehicle 100, and lamp 20b emits the second light toward the front of vehicle 100.

Fig. 5 is a diagram illustrating the light distribution pattern 300 of the high beam when the distance between the retroreflective article 401 and the vehicle 100 is smaller than a predetermined distance. The light distribution pattern 300 shown in fig. 5 is formed by combining the light distribution pattern 310 shown in fig. 6 formed by the first light and the light distribution pattern 320 shown in fig. 7 formed by the second light. In fig. 6, the region in the light distribution pattern 310 where the retroreflective article 401 and the support portion 403 overlap is referred to as a region AR1, and in fig. 7, the region in the light distribution pattern 320 where the retroreflective article 401 and the support portion 403 overlap is referred to as a region AR 2. As described above, since the first light amount is smaller than the second light amount, the light amount in the area AR1 is smaller than the light amount in the area AR 2.

In fig. 6, the region of the light distribution pattern 310 excluding the region AR1 is referred to as a region AR 11. Since the first light is also emitted to the area AR11, the amount of light in the area AR1 is the same as the amount of light in the area AR 11. In fig. 7, the region of the light distribution pattern 320 excluding the region AR2 is referred to as a region AR 22. Since the second light is also emitted to the area AR22, the amount of light in the area AR2 is the same as the amount of light in the area AR 22. As described above, since the first light amount is smaller than the second light amount, the light amount in the area AR11 is smaller than the light amount in the area AR 22.

Next, an example of control of the sum of the first light amount and the second light amount will be described using numerical values. The numerical values used herein are described for convenience of reflecting the magnitude relation of the light quantity, and do not represent actual numerical values of the first light quantity and the second light quantity.

When the distance between the retroreflective article 401 and the vehicle 100 is equal to or greater than the predetermined distance, the control unit 40 controls, for example, the

lamps

20a and 20b so that the first light amount is "100" and the second light amount is "100" in step S4. In this case, the sum of the first light amount and the second light amount is "200".

On the other hand, when the distance between the retroreflective article 401 and the vehicle 100 is less than the predetermined distance, the control unit 40 controls, for example, the

lamps

20a and 20b so that the first light amount is "60" and the second light amount is "80" in step S5. In this case, the first light amount is smaller than the second light amount, and the sum of the first light amount and the second light amount is "140".

Here, the sum "200" of the first light amount and the second light amount when the distance between the retroreflective object 401 and the vehicle 100 is equal to or greater than the predetermined distance is compared with the sum "140" of the first light amount and the second light amount when the distance between the retroreflective object 401 and the vehicle 100 is smaller than the predetermined distance. When comparing the both, the control unit 40 controls the lamp 20a and the lamp 20b such that the sum of the first light amount and the second light amount is smaller when the distance between the retroreflective object 401 and the vehicle 100 is smaller than the predetermined distance than when the distance between the retroreflective object 401 and the vehicle 100 is equal to or larger than the predetermined distance. Next, the first light amount "100" and the second light amount "100" when the distance between the retro-reflecting object 401 and the vehicle 100 is equal to or greater than the predetermined distance, and the first light amount "60" and the second light amount "80" when the distance between the retro-reflecting object 401 and the vehicle 100 is smaller than the predetermined distance are compared. When comparing the two, the control unit 40 controls the lamp 20a and the lamp 20b so that the first light amount and the second light amount are reduced when the distance between the retro-reflective object 401 and the vehicle 100 is smaller than the predetermined distance or more, as compared with the case where the distance between the retro-reflective object 401 and the vehicle 100 is equal to or longer than the predetermined distance.

As described above, when the distance between the retroreflective object 401 and the vehicle 100 is smaller than the predetermined distance, the first light amount is smaller than when the distance between the retroreflective object 401 and the vehicle 100 is equal to or larger than the predetermined distance. Therefore, the first light amount in the area AR11 shown in fig. 6 is smaller than the light amount in the light distribution pattern formed by the first light when the distance between the retroreflective object 401 and the vehicle 100 is equal to or greater than the predetermined distance. When the distance between the retroreflective article 401 and the vehicle 100 is smaller than the predetermined distance, the second light amount is smaller than when the distance between the retroreflective article 401 and the vehicle 100 is equal to or longer than the predetermined distance. Therefore, the light amount in the area AR22 shown in fig. 7 is smaller than the light amount in the light distribution pattern formed by the second light when the distance between the retroreflective object 401 and the vehicle 100 is equal to or greater than the predetermined distance.

When the distance between the retro-reflecting object 401 and the vehicle 100 is smaller than the predetermined distance, the sum of the first light amount and the second light amount may be smaller as described above, as compared with the case where the distance between the retro-reflecting object 401 and the vehicle 100 is equal to or longer than the predetermined distance. For example, the control unit 40 may control the lamp 20a and the lamp 20b such that the first light amount is "100" and the second light amount is "100" when the distance between the retroreflective article 401 and the vehicle 100 is equal to or greater than the predetermined distance, and the first light amount is "50" and the second light amount is "110" when the distance between the retroreflective article 401 and the vehicle 100 is less than the predetermined distance. Therefore, the control unit 40 may control the lamp 20a and the lamp 20b such that the first light amount is reduced and the second light amount is increased when the distance between the retroreflective object 401 and the vehicle 100 is smaller than the predetermined distance, as compared with when the distance between the retroreflective object 401 and the vehicle 100 is equal to or greater than the predetermined distance.

When the sum of the first light amount and the second light amount is controlled as described above, the process proceeds to step S6.

(step S6)

In this step, the control unit 40 determines whether or not the difference between the light amount of the light emitted from the pair of lamps 20 toward the retroreflective article 401 and the light amount of the light emitted from the pair of lamps 20 toward the front of the vehicle 100 excluding the retroreflective article 401 is within a predetermined range. When the control unit 40 determines that the difference falls within the predetermined range, the process returns to step S1. If the control unit 40 determines that the difference does not fall within the predetermined range, the process proceeds to step S7.

(step S7)

In this step, the controller 40 controls the pair of lamps 20 so that the difference falls within a predetermined range. Here, for example, the control unit may control at least one of the lamp 20a and the lamp 20b so that the first light amount is smaller than the second light amount and the difference falls within a predetermined range. When a subject such as a pedestrian is located in front of the vehicle 100 excluding the retroreflective object 401, the above-described difference is converged to a predetermined range, thereby suppressing a relative difference between the brightness of the retroreflective object 401 and the brightness of the subject. When the first light amount and the second light amount are controlled, the process returns to step S6.

As described above, the vehicle headlamp 10 of the present embodiment includes the pair of lamps 20 disposed on the left and right sides in front of the vehicle 100, and the control unit 40 that controls the pair of lamps 20. The control unit 40 controls the lamp 20a and the lamp 20b such that, when a signal indicating that the retro-reflective object 401 located in front of the vehicle 100 is detected is input from the detection device 50, a first light amount of first light emitted from the lamp 20a located on the side of the retro-reflective object 401 toward the retro-reflective object 401 is smaller than a second light amount of second light emitted from the lamp 20b located on the opposite side of the retro-reflective object 401 toward the retro-reflective object 401.

When the retroreflective object 401 reflects light, the intensity of the light reflected from the retroreflective object 401 toward the vehicle 100 as the host vehicle tends to be higher as the amount of displacement of the lamp 20 with respect to the retroreflective object 401 in the left-right direction of the vehicle 100 is smaller. When the retroreflective article 401 is positioned on the left side of the vehicle 100, in the vehicle headlamp 10 of the present embodiment, the lamp 20a is positioned on the retroreflective article 401 side, and the lamp 20b is positioned on the opposite side of the retroreflective article 401 side with respect to the lamp 20 a. Therefore, the amount of offset of the lamp 20a with respect to the retro-reflective object 401 in the left-right direction of the vehicle 100 is smaller than the amount of offset of the lamp 20b with respect to the retro-reflective object 401 in the left-right direction of the vehicle 100. In the vehicle headlamp 10 of the present embodiment, when the retroreflective article 401 is detected, the first light quantity of the first light directed toward the retroreflective article 401 from the lamp 20a located on the retroreflective article 401 side is smaller than the second light quantity of the second light directed toward the retroreflective article 401 from the lamp 20b located on the opposite side to the retroreflective article 401 side. In this way, when the first light amount is smaller than the second light amount, the intensity of the reflected light can be suppressed as compared with a case where the first light amount is not smaller than the second light amount, and glare to the driver of the host vehicle can be suppressed even if the reflected light travels toward the host vehicle. Therefore, according to the vehicle headlamp 10, the degradation of the visibility of the driver can be suppressed. The control unit 40 may determine that the retroreflective article 401 is detected when the determination result of the determination unit 35 indicating whether or not the retroreflective article satisfies the predetermined requirement is input. In this case, the detection device 50 may not output a signal indicating that the retro-reflective object 401 is detected to the control unit 40.

The vehicle headlamp 10 according to the present embodiment further includes a determination unit 35, and the determination unit 35 determines whether or not the retroreflective article 401 satisfies a predetermined condition that the amount of light reflected from the retroreflective article 401 is equal to or greater than a predetermined value when a signal indicating the state of the retroreflective article 401 is input from the detection device 50. The control unit 40 controls the lamp 20a and the lamp 20b so that the total of the first light amount and the second light amount is smaller when the determination unit 35 determines that the retroreflective article 401 satisfies the predetermined requirement than when the determination unit 35 determines that the retroreflective article 401 does not satisfy the predetermined requirement.

According to the vehicle headlamp 10, the intensity of the reflected light can be further suppressed in a state where the retro-reflecting object 401 satisfies the predetermined requirement, as compared with a state where the retro-reflecting object 401 does not satisfy the predetermined requirement. Therefore, according to the vehicle headlamp 10, the degradation of the visibility of the driver can be further suppressed.

In the vehicle headlamp 10 according to the present embodiment, the control unit 40 controls the lamp 20a and the lamp 20b such that, when the determination unit 35 determines that the retroreflective article 401 satisfies the predetermined requirement, the first light amount and the second light amount are reduced as compared to when the determination unit 35 determines that the retroreflective article 401 does not satisfy the predetermined requirement.

According to the vehicle headlamp 10, in the state where the retroreflective article 401 satisfies the predetermined requirement, the irradiation of the first light and the second light to the retroreflective article 401 is suppressed, and the intensity of the reflected light can be further suppressed, compared to the state where the retroreflective article 401 does not satisfy the predetermined requirement. Therefore, according to the vehicle headlamp 10, the degradation of the visibility of the driver can be further suppressed.

In the vehicle headlamp 10 according to the present embodiment, the control unit 40 may control the lamp 20a and the lamp 20b such that the first light amount is smaller and the second light amount is larger in the case where the determination unit 35 determines that the retroreflective article 401 satisfies the predetermined requirement than in the case where the determination unit 35 determines that the retroreflective article 401 does not satisfy the predetermined requirement.

In this case, since the retroreflective article 401 is brighter by the second light as compared with the case where the second light amount is not increased, the driver can be assured of visual confirmation of the retroreflective article 401.

In the vehicle headlamp 10 of the present embodiment, the control unit 40 controls the pair of lamps 20 as follows: when the determination unit 35 determines that the retroreflective article 401 satisfies the predetermined requirement, the difference between the light amount of light emitted from the pair of lamps 20 toward the retroreflective article 401 and the light amount of light emitted from the pair of lamps 20 toward the front of the vehicle 100 excluding the retroreflective article 401 is within a predetermined range.

When an object such as a pedestrian is located in front of the vehicle 100 excluding the retroreflective object 401, the above difference is converged to a predetermined range, thereby suppressing a relative difference between the brightness of the retroreflective object 401 and the brightness of the object. Therefore, according to the vehicle headlamp 10, it is possible to suppress a reduction in the visibility of the object by the driver.

In addition, when the distance between the retroreflective object 401 and the vehicle 100 is less than the predetermined distance in a state where the light amount of the light emitted from the pair of lamps 20 is not changed, the intensity of the light reflected from the retroreflective object 401 toward the host vehicle tends to be stronger than in a state where the distance is equal to or greater than the predetermined distance. However, in the vehicle headlamp 10 of the present embodiment, the state satisfying the predetermined requirement is the state in which the distance between the retroreflective article 401 and the vehicle 100 is smaller than the predetermined distance. When the distance is smaller than the predetermined distance, the control unit 40 controls the pair of lamps 20 so that the first light amount is smaller than the second light amount, as described above. Therefore, when the distance is less than the predetermined distance, the intensity of the reflected light traveling from the retro-reflective object 401 toward the host vehicle can be suppressed, the application of glare can be suppressed, and the reduction in the visibility of the driver can be suppressed, as compared with the case where the distance is equal to or greater than the predetermined distance.

The present invention will be described below by taking the above embodiments as examples, but the present invention is not limited to these embodiments.

The configuration of the lamp 20a is not particularly limited to the above. The lamp 20a may be configured to scan light emitted from the light source and emit the light forward using, for example, MEMS (Micro Electro Mechanical Systems) or galvano mirrors. The lamp 20a may be configured to diffract light emitted from the light source using LCOS (Liquid Crystal On Silicon), a diffraction grating, or the like to form a desired light distribution pattern and emit the light forward. The lamp 20a may be a parabolic lamp, a projection lamp, a direct-projection lens lamp, or the like, for example. The lamp 20a may have a plurality of light emitting elements arranged in parallel. The plurality of light emitting elements are arranged in a matrix, are arranged in rows in the vertical direction and the horizontal direction, and emit light forward. Each of the plurality of light emitting elements can individually change the amount of light emitted by the light emitting element by the power supplied to the light emitting element. These light emitting elements are phosphor-type LEDs that emit white light, and the lamp 20a is a so-called LED array. The number and structure of the light-emitting elements are not particularly limited. For example, the light emitting element may be a plurality of LEDs that emit light having different wavelengths, or may be a plurality of LDs (Laser diodes) that emit light having different wavelengths. The lamp 20b has the same structure as the lamp 20a, but may have a structure different from that of the lamp 20 a.

The captured image may be at least one of a moving image and a still image.

When the retroreflective article is positioned diagonally forward on the right of the vehicle 100, the lamp 20b is positioned on the retroreflective article side, and the lamp 20a is positioned on the opposite side of the retroreflective article side. In this case, the control of the light amount of the light emitted from the

lamps

20b and 20a is the same as the control of the light amount of the light emitted from the

lamps

20a and 20b described in the embodiment. Although the control of the light amount using the retro-reflective object 401 is described, it is not necessarily limited thereto. The light amount may be controlled by using a reflecting object that reflects the light from the pair of lamps 20 at the same reflection angle as the incident angle of the light, for example.

The control of the first light amount and the second light amount in the light distribution pattern of the high beam is described, but the first light amount and the second light amount are also controlled in the light distribution pattern of the low beam similarly to the light distribution pattern of the high beam.

The detection device 50 detects the presence of the retro-reflective object 401 and the presence position of the retro-reflective object 401 from the captured image captured by the camera, but is not limited thereto. When a millimeter-wave radar capable of detecting the retro-reflecting object 401, a driver, or the like is mounted, the detection device 50 may detect the presence of the retro-reflecting object 401 and the presence position of the retro-reflecting object 401 based on a signal input from the millimeter-wave radar, the driver, or the like.

Further, the millimeter wave radar transmits millimeter waves to the retro-reflecting object 401, and receives reflected waves reflected by hitting the retro-reflecting object 401. The millimeter wave radar outputs a signal indicating the reception result to the calculation section. The reception result may be included in the state of the retro-reflective object 401. The calculation portion may also calculate the distance between the vehicle 100 and the retro-reflective object 401 based on the reception result input from the millimeter wave radar.

The detection device 50 may include a stereo camera for capturing an image of the front side of the vehicle 100. The stereo camera includes two cameras, and outputs captured images captured by the respective cameras to the calculation unit. The captured image may be included in a state of the retro-reflective object 401. The calculation unit may calculate the distance between the vehicle 100 and the retroreflective article 401 based on stereo matching that obtains parallax at corresponding pixels that are pixels corresponding to each other in the two captured images. Therefore, the calculation unit calculates the distance between the vehicle 100 and the retro-reflective object 401 based on the captured image from the stereo camera. The determination unit 35 may determine which of the right side and the left side of the vehicle 100 the retroreflective article 401 is located on based on stereo matching.

The detection unit of the detection device 50 may detect a temporal change amount of the size of the retroreflective article 401 in the captured image from the captured image subjected to the image processing by the image processing unit. The amount of change is contained in a signal indicating the state of the retro-reflective object. When the vehicle 100 distant from the retroreflective object 401 over time approaches the object, the amount of change in the size of the retroreflective object 401 is small, and when the vehicle 100 that has traveled forward and approaches the object over time approaches the retroreflective object 401 further, the amount of change in the size of the retroreflective object 401 is large. The size of the retro-reflective object 401 indicates, for example, the area of the retro-reflective object 401, the width of the retro-reflective object 401, and the like. When detecting the retroreflective article 401 positioned in front of the vehicle 100, the detection device 50 outputs a signal indicating the state of the retroreflective article, such as the ratio of the retroreflective article 401 and the amount of change, in the captured image to the calculation unit. The calculation unit may calculate the distance based on the ratio and the change amount.

The signal output from the detection device 50 to the determination unit 35 need not be only the state of the retroreflective article, but may indicate the state of an article other than the retroreflective article. Examples of the state include the presence of an object other than the retroreflective object, the presence position of the object, and the proportion of the object in the captured image. The object to be detected by the detection device 50, the number of types of objects, and the configuration of the detection device 50 are not particularly limited.

The predetermined requirement is not particularly limited, and may be the apparent size of the above-described retroreflective article 401, or the like, without being limited to the distance. When the predetermined requirement is the apparent size of the retroreflective article 401, a state in which the predetermined requirement is satisfied indicates a state in which the apparent size of the retroreflective article 401 is equal to or larger than a predetermined value. In this case, the detection unit of the detection device 50 detects the size of the retroreflective article 401 in the captured image from the captured image subjected to the image processing by the image processing unit, as described above. The determination unit 35 determines whether or not the retroreflective article is in a state satisfying a predetermined requirement based on the size of the retroreflective article 401. The predetermined value is recorded in the recording unit 70 as a threshold value, and may be changed according to the traveling condition of the vehicle 100 such as daytime and nighttime. Even if the distance between the retroreflective article 401 and the vehicle 100 is equal to or greater than the predetermined distance, when the apparent size of the retroreflective article 401 is equal to or greater than the predetermined value, part of the light from the vehicle 100 is emitted from the retroreflective article 401 to the vehicle 100 as reflected light, and there is a possibility that glare may be caused to the driver of the vehicle, as compared with the case where the apparent size of the retroreflective article 401 is smaller than the predetermined value. As described above, when the state satisfying the predetermined requirement is the state in which the apparent size of the retroreflective article 401 is equal to or larger than the predetermined value, the control unit 40 controls the pair of lamps 20 so that the first light amount is smaller than the second light amount, as described above. Therefore, even when the distance between the retroreflective object 401 and the vehicle 100 is equal to or greater than the predetermined distance and the apparent size of the retroreflective object 401 is equal to or greater than the predetermined value, the intensity of the reflected light traveling from the retroreflective object 401 to the host vehicle can be suppressed, the application of glare can be suppressed, and the reduction in the visibility of the driver can be suppressed. In the above description, the apparent size of the retroreflective article 401 is used, but the predetermined requirement may be the proportion of the retroreflective article 401 in the captured image. When the predetermined requirement is the ratio, the state in which the predetermined requirement is satisfied is a state in which the ratio is equal to or greater than a predetermined value.

In the above description, a state satisfying a predetermined requirement is a state in which the retroreflective article 401 is again at a predetermined size or larger, but the present invention is not limited to this. For example, the state satisfying the predetermined requirement may be a state in which any one of the state in which the distance between the retroreflective article 401 and the vehicle 100 described in the embodiment is smaller than the predetermined distance, the state in which the apparent size of the retroreflective article 401 is equal to or larger than the predetermined value, and the state in which the ratio is equal to or larger than the predetermined value is combined.

In step S5 shown in fig. 3, lamp 20a may be turned off to stop the emission of the first light toward the front of vehicle 100. Alternatively, the determination unit may output a signal indicating the state of the retroreflective article 401 to the control unit 40, and the control unit 40 may suppress the emission of the first light toward the retroreflective article 401 among the first light emitted toward the front of the vehicle 100 by setting the reflection control surface 23r to the second inclined state based on the signal. In the case where the lamp 20a is a so-called LED array, the light emitting element that emits the first light toward the retroreflective article, out of the plurality of light emitting elements of the lamp 20a, may be turned off, and the emission of the first light toward the retroreflective article, out of the first light emitted toward the front of the vehicle 100, may be stopped. In this case, for example, it is determined that the main body outputs a signal indicating the state of the retroreflective article to the control unit 40, and the control unit 40 may control the light emitting element that emits the first light toward the retroreflective article, among the plurality of light emitting elements of the lamp 20a, based on the signal.

The second light amount of the second light is "100" when the retroreflective object 401 does not satisfy the predetermined requirement, and is "80" or "110" when the retroreflective object 401 satisfies the predetermined requirement, but the present invention is not limited to this. The second light amount of the second light may be the same when the retroreflective object 401 satisfies the predetermined requirement and when the retroreflective object 401 does not satisfy the predetermined requirement.

The first light and the second light may be emitted toward at least the retro-reflective object 401.

In the vehicle headlamp 10 according to the present embodiment, of the first light and the second light emitted toward the front of the vehicle 100, the amount of light directed from the lamp 20a toward at least the retroreflective article 401 may be smaller than the amount of light directed from the lamp 20b toward at least the retroreflective article 401. In this case, for example, it may be determined that the main body section outputs a signal indicating the state of the retroreflective article 401 to the control section 40, and the control section 40 may suppress the emission of the first light and the second light toward the retroreflective article 401 among the first light and the second light emitted toward the front of the vehicle 100 by setting the reflection control surface 23r to the second inclined state based on the signal. In the case where the

lamp

20a or 20b is a so-called LED array, the control unit 40 may control the light emitting element that emits the first light toward the retroreflective article among the plurality of light emitting elements of the lamp 20a, and control the light emitting element that emits the second light toward the retroreflective article among the plurality of light emitting elements of the lamp 20 b. The light amount of light directed from the lamp 20a to the front of the vehicle 100 excluding the retro-reflective object 401 may be the same as, larger than, or smaller than the light amount of light directed from the lamp 20b to the retro-reflective object 401 and the light amount of light directed from the lamp 20b to the front of the vehicle 100 excluding the retro-reflective object 401. Further, the light amount of the light directed from the lamp 20b toward the retro-reflective object 401 may be smaller than the light amount of the light directed from the lamp 20b toward the front of the vehicle 100 excluding the retro-reflective object 401.

As described above, according to the present invention, there is provided a vehicle headlamp capable of suppressing a reduction in visibility of a driver, and the vehicle headlamp can be used in the field of vehicle headlamps such as automobiles.

Claims

1. A vehicle headlamp is characterized by comprising:

a pair of lamps disposed on the left and right of a front portion of a vehicle;

a control unit that controls the pair of lamps;

when a signal indicating that a regressive reflection object located in front of the vehicle is detected is input from the detection device, the control unit controls the one lamp and the other lamp such that the amount of light emitted from at least one of the lamps located on the regressive reflection object side of the pair of lamps toward the regressive reflection object is smaller than the amount of light emitted from at least one of the lamps located on the other side of the regressive reflection object side of the pair of lamps toward the regressive reflection object.

2. The vehicular headlamp according to claim 1,

the image processing apparatus further includes a determination unit configured to determine whether or not the retroreflective article satisfies a predetermined condition that the amount of reflected light from the retroreflective article is equal to or greater than a predetermined value when a signal indicating the state of the retroreflective article is input from the detection device,

when the determination unit determines that the retro-reflecting object satisfies the predetermined requirement, the control unit controls the one lamp and the other lamp such that a sum of the light amount of the light from the one lamp and the light amount of the light from the other lamp is smaller than when the determination unit determines that the retro-reflecting object does not satisfy the predetermined requirement.

3. The vehicle headlamp according to claim 2,

when the determination unit determines that the retro-reflective object satisfies the predetermined requirement, the control unit controls the one lamp and the other lamp such that the amount of light of the light from the one lamp and the amount of light of the other lamp are reduced, respectively, as compared to when the determination unit determines that the retro-reflective object does not satisfy the predetermined requirement.

4. The vehicular headlamp according to claim 2,

when the determination unit determines that the retro-reflecting object satisfies the predetermined requirement, the control unit controls the one lamp and the other lamp such that the amount of light of the light from the one lamp is reduced and the amount of light of the light from the other lamp is increased, as compared to when the determination unit determines that the retro-reflecting object does not satisfy the predetermined requirement.

5. The vehicular headlamp according to any one of claims 2 to 4,

when the determination unit determines that the retroreflective article satisfies the predetermined requirement, the control unit controls the pair of lamps so that a difference between a light amount of light emitted from the pair of lamps toward the retroreflective article and a light amount of light emitted from the pair of lamps toward the front of the vehicle excluding the retroreflective article is within a predetermined range.

6. The vehicular headlamp according to any one of claims 2 to 5,

the state satisfying the predetermined requirement is a state in which the distance between the retro-reflective object and the vehicle is smaller than a predetermined distance.

7. The vehicular headlamp according to any one of claims 2 to 6,

the state satisfying the predetermined requirement is a state in which the apparent size of the retroreflective article is equal to or larger than a predetermined value.