JP7807315B2 - Vehicle headlights - Google Patents

Description

The present invention relates to a vehicle headlamp.

Vehicle headlights, such as automobile headlights, are known to change the light distribution pattern of the emitted light, and Patent Document 1 below discloses such a vehicle headlight.

The vehicle headlamp described in Patent Document 1 below comprises a lighting unit that can change the light distribution pattern of the emitted light, and a control unit. The control unit controls the lighting unit based on information from a detection device that detects other vehicles located in front of the vehicle, suppressing the illumination of light onto the other vehicles while illuminating the area around the other vehicles. For this reason, Patent Document 1 below claims that the vehicle headlamp can suppress glare to drivers of other vehicles located in front of the vehicle.

JP 2011-031807 A

When an area of reduced light intensity is formed, as in the vehicle headlamp of Patent Document 1, the driver of the vehicle tends to perceive this area and the surrounding area as dark, which can reduce visibility ahead of the vehicle. Furthermore, with the vehicle headlamp of Patent Document 1, when there are multiple vehicles ahead of the vehicle, the light intensity is reduced in one area that overlaps with these other vehicles. As a result, the area between adjacent vehicles also becomes dark, reducing visibility ahead of the vehicle. Therefore, there is a demand for reducing this reduction in visibility ahead of the vehicle.

Therefore, the present invention aims to provide a vehicle headlamp that can minimize a decrease in visibility ahead of the vehicle.

To achieve the above object, the vehicle headlamp of the present invention comprises a lighting unit capable of changing the light distribution pattern of the emitted light, and a control unit that controls the lighting unit in response to a signal input from a detection device that detects a predetermined object located in front of the vehicle. When the predetermined object is not located in front of the vehicle, the control unit controls the lighting unit to emit light having a light distribution pattern that includes a predetermined light distribution pattern. When multiple predetermined objects are located in front of the vehicle, the control unit controls the lighting unit so that, compared to when the predetermined objects are not located in front of the vehicle, the amount of light in multiple first regions that respectively overlap at least a portion of each of the predetermined objects in the predetermined light distribution pattern decreases, the amount of light in multiple second regions that respectively follow at least a portion of the outer edge of each of the first regions increases, and the width of each second region in a direction perpendicular to the direction along the outer edge of the first region changes in accordance with the sum of the areas of the multiple first regions.

This vehicle headlamp changes the light distribution pattern of the emitted light depending on the situation ahead of the vehicle, reducing the amount of light irradiated onto multiple objects located ahead of the vehicle. For example, if the multiple objects include other vehicles, the amount of light irradiated onto the other vehicles is reduced. This reduces glare to the drivers of the other vehicles. Furthermore, if the multiple objects include retroreflective objects such as signs, the amount of light irradiated onto the retroreflective objects is reduced. This reduces the amount of light reflected off the retroreflective objects and toward the vehicle, reducing glare to the driver of the vehicle caused by the reflected light. This vehicle headlamp also reduces the darkening of the areas between adjacent objects compared to when a single first region is provided for multiple objects. This vehicle headlamp also reduces the darkening of the area around the first region, where the light amount is reduced, compared to when there is no second region, thereby reducing reduced visibility ahead of the vehicle. Furthermore, in this vehicle headlamp, as described above, the width of each second region varies depending on the total area of the multiple first regions. The greater the proportion of the first regions in the entire predetermined light distribution pattern, the darker the predetermined light distribution pattern tends to appear overall. Therefore, if the width of each second region increases as the total area of the multiple first regions increases, the darker the predetermined light distribution pattern appears can be prevented from appearing overall.

The control unit may control the lighting unit so that the total amount of dimming of the first regions is the same as the total amount of dimming of the second regions.

This configuration can reduce the increase in energy consumption compared to when the total amount of light increase in the multiple second regions is greater than the total amount of light decrease in the multiple first regions.

The control unit may control the lighting unit so that the widths of the second regions are the same.

This configuration can reduce the control load on the control unit compared to when the widths of multiple second regions are different from one another.

The control unit may control the lighting unit so that the amount of light increase per unit area of the multiple second regions is the same.

This configuration can reduce the control load on the control unit compared to when the amount of light increase per unit area of the multiple second regions differs from one another.

The control unit may control the lighting unit so that the amount of change in the width of each of the second regions relative to the amount of change in the total area of the plurality of first regions decreases as the total area of the plurality of first regions increases.

When adjacent second regions overlap, the area where the second regions overlap may become too bright, which may cause the driver of the vehicle to feel uncomfortable. Furthermore, the larger the total area of the multiple first regions, the more likely adjacent first regions and adjacent second regions tend to be closer to each other. Therefore, by using the above configuration, it is possible to make it less likely for adjacent second regions to overlap, compared to when the amount of change in the width of each second region relative to the amount of change in the total area of the multiple first regions is constant and not dependent on the total area of the multiple first regions, thereby reducing the sense of discomfort felt by the driver of the vehicle.

The control unit may control the lighting unit so that the width of each of the second regions does not change when the ratio of the total area of the plurality of first regions to the area of a predetermined light distribution pattern is equal to or less than a predetermined value.

The smaller the above ratio, the less likely the specified light distribution pattern will appear dark overall. Therefore, by using the above configuration, it is possible to reduce the control load on the control unit while preventing the specified light distribution pattern from appearing dark overall.

The control unit may control the lighting unit so that the width of each of the second regions becomes narrower as the number of first regions increases.

This configuration makes it less likely for adjacent second regions to overlap, reducing the sense of discomfort felt by the driver of the vehicle.

As described above, the present invention provides a vehicle headlamp that can minimize a decrease in visibility ahead of the vehicle.

1 is a plan view conceptually showing a vehicle equipped with a vehicle headlamp according to an embodiment of the present invention. 2 is a cross-sectional view schematically showing a lamp unit of one of the vehicle headlights shown in FIG. 1 ; FIG. 3 is a front view schematically showing the light source unit shown in FIG. 2 . 4 is a control flowchart of a control unit in the present embodiment. FIG. 4 is a diagram showing an example of a high beam light distribution pattern in the present embodiment. FIG. 6 is a diagram similar to FIG. 5 showing an example of an ADB light distribution pattern in this embodiment. FIG. 7 is a diagram similar to FIG. 6 showing an example of an ADB light distribution pattern after a predetermined time has elapsed from the state shown in FIG. 6 .

Below, embodiments of the vehicle headlamp according to the present invention are illustrated with reference to the accompanying drawings. The embodiments illustrated below are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. The present invention can be modified and improved without departing from its spirit. Furthermore, the present invention may also be achieved by appropriately combining the components of the embodiments illustrated below. Note that in the drawings referenced below, the dimensions of each component may be altered to facilitate understanding.

Figure 1 is a plan view conceptually illustrating a vehicle equipped with vehicle headlights according to an embodiment of the present invention. As shown in Figure 1, the vehicle 100 according to this embodiment is an automobile, and includes a pair of left and right vehicle headlights 1, a light switch 110, and a detection device 120 that detects a predetermined object located in front of the vehicle 100.

In this embodiment, each vehicle headlamp 1 mainly comprises a lamp unit 5, a control unit CO, a memory ME, and a power supply circuit 50. In this specification, unless otherwise specified, "right" means the right side from the perspective of the driver of the vehicle 100, which is the host vehicle, and "left" means the left side from the perspective of the driver of the vehicle 100, which is the host vehicle.

In this embodiment, the configuration of one vehicle headlamp 1 is the same as the configuration of the other vehicle headlamp 1, except that the shape of the lamp unit 5 is generally symmetrical. For this reason, the following will only describe one vehicle headlamp 1, and a description of the other vehicle headlamp 1 will be omitted.

Figure 2 is a cross-sectional view that schematically shows the lamp section 5 of one of the vehicle headlamps 1 shown in Figure 1. As shown in Figure 2, the lamp section 5 mainly comprises a lamp unit 10 and a housing 16.

The housing 16 mainly comprises a housing 17 and a front cover 18. The front cover 18 transmits light emitted from the lighting unit 10. The housing 17 is box-shaped with an opening at the front, and the front cover 18 is fixed to the housing 17 so as to cover the opening. In this way, an accommodation space surrounded by the housing 17 and the front cover 18 is formed in the housing 16, and the lighting unit 10 is disposed in this accommodation space. The lighting unit 10 is capable of changing the light distribution pattern of the emitted light, and mainly comprises a light source unit 12 and a projection lens 15.

Figure 3 is a front view schematically illustrating the light source unit 12 shown in Figure 2. As shown in Figure 3, the light source unit 12 of this embodiment has a plurality of light-emitting elements 13 as a light-emitting unit that emits light, and a circuit board 14 on which the plurality of light-emitting elements 13 are mounted. The plurality of light-emitting elements 13 are arranged in a matrix to form rows in the vertical and horizontal directions, and emit light forward. The amount of light emitted by each of the light-emitting elements 13 can be individually changed. In this embodiment, the light-emitting elements 13 are micro LEDs (Light Emitting Diodes), and the light source unit 12 is a so-called micro LED array. Note that the number of light-emitting elements 13 lined up in the horizontal direction and the number of light-emitting elements 13 lined up in the vertical direction are not particularly limited.

In this embodiment, each light-emitting element 13 corresponds to a pixel of an image generated by the image generation unit of the control unit CO, which will be described later. The light source unit 12 adjusts the amount of light emitted from each light-emitting element 13 according to the pixel data corresponding to that light-emitting element 13, thereby emitting light based on this image and forming a light distribution pattern based on that image using that light. In this embodiment, there is a one-to-one correspondence between light-emitting elements 13 and pixels, but this is not particularly limited.

The projection lens 15 is positioned in front of the light source unit 12. Light emitted from the light source unit 12 enters the projection lens 15, and the divergence angle of this light is adjusted by the projection lens 15. As a result, the light with the divergence angle adjusted by the projection lens 15 is emitted from the lamp unit 10 and is irradiated from the lamp unit 5 through the front cover 18 toward the front of the vehicle 100. The projection lens 15 in this embodiment is a lens with convex light entrance and exit surfaces, and the rear focal point of the projection lens 15 is located on or near the light exit surface of one of the light-emitting elements 13 in the light source unit 12. As a result, the light distribution pattern of the light irradiated toward the front of the vehicle 100 is a light distribution pattern obtained by vertically and horizontally inverting the light distribution pattern of the light emitted by the light source unit 12, and the image representing this light distribution pattern is a vertically and horizontally inverted image representing the light distribution pattern of the light emitted by the light source unit 12.

Next, the control unit CO shown in FIG. 1 is composed of, for example, an integrated circuit such as a microcontroller, IC (Integrated Circuit), LSI (Large-scale Integrated Circuit), or ASIC (Application Specific Integrated Circuit), or an NC (Numerical Control) device. Furthermore, if the control unit CO uses an NC device, it may or may not use a machine learning device.

Memory ME stores information and is configured to be able to read the stored information. Memory ME is, for example, a non-transitory recording medium, and is preferably a semiconductor recording medium such as RAM (Random Access Memory) or ROM (Read Only Memory), but can also include any type of recording medium, such as an optical recording medium or a magnetic recording medium. Note that "non-transitory" recording medium includes all computer-readable recording media except for transient, propagating signals, and does not exclude volatile recording media. This memory ME stores various programs for controlling the lighting unit 10 and information necessary for such control, and the control unit CO reads the programs and information stored in memory ME.

In this embodiment, the control unit CO has an image generation unit 20 and a light distribution control unit 40, and receives signals from the detection device 120 (described later) after reading various programs from the memory ME. The image generation unit 20 generates an image based on the image stored in the memory ME. In this embodiment, this image is a grayscale image in which the data for each pixel is a grayscale value, and the larger the grayscale value, the brighter the pixel. However, the data for each pixel is not particularly limited. In addition, image information may be read from a memory outside the vehicle 100 via wireless communication equipment provided in the vehicle 100.

In this embodiment, the image stored in memory ME is a high beam image. A high beam image is an image in which light emitted from the light source unit 12 forms a high beam light distribution pattern. The image generation unit 20 of this embodiment processes the high beam image based on information indicated by a signal input from the detection device 120, thereby generating an image representing an ADB light distribution pattern in which the amount of light in some areas of the high beam light distribution pattern is reduced and the amount of light in other areas is increased.

In this embodiment, the light distribution control unit 40 controls the lamp unit 10 by controlling the power supply circuit 50 based on high beam image information stored in memory ME or image information generated by the image generation unit 20. As described above, the image generation unit 20 generates an image based on information indicated by a signal input from the detection device 120. Therefore, it can be understood that the control unit CO receives a signal from the detection device 120 and controls the lamp unit 10 using the image generation unit 20 and light distribution control unit 40.

The power supply circuit 50 includes a driver. When a control signal is input from the light distribution control unit 40, the driver adjusts the power supplied from a power supply (not shown) to each light-emitting element 13 of the light source unit 12. In this way, the amount of light emitted from each light-emitting element 13 is adjusted, and the light source unit 12 emits light based on a high beam image or an image generated by the image generation unit 20. Light having an ADB light distribution pattern represented by the high beam or the image generated by the image generation unit 20 is then emitted from the lamp unit 10. Note that light-emitting elements 13 corresponding to pixels with larger gradation values are supplied with more power. In this embodiment, when the gradation value exceeds a threshold, power corresponding to the threshold is supplied to the light-emitting element 13. In this embodiment, the driver of the power supply circuit 50 adjusts the power supplied to each light-emitting element 13 using PWM (Pulse Width Modulation) control, thereby adjusting the amount of light emitted from each light-emitting element 13. However, the method for adjusting the amount of light emitted from each light-emitting element 13 is not particularly limited.

The light switch 110 in this embodiment is a switch that selects whether or not to emit light. When the light switch 110 is on, it outputs a signal indicating light emission to the control unit CO via the ECU (Electronic Control Unit) 101 of the vehicle 100, and when it is off, it does not output a signal.

The detection device 120 of this embodiment detects a predetermined object located in front of the vehicle 100. Examples of predetermined objects include other vehicles such as preceding vehicles and oncoming vehicles, retroreflective objects, people such as pedestrians, and obstacles. The retroreflective objects of this embodiment are objects that do not emit light themselves but retroreflect irradiated light at a predetermined spread angle. Examples of such retroreflective objects include road signs and delineators. The detection device 120 of this embodiment includes an image acquisition unit 121 and a detection unit 122.

The image acquisition unit 121 acquires an image of the area ahead of the vehicle 100, and the image acquired by the image acquisition unit 121 includes at least a portion of the area that can be irradiated with light emitted from the pair of vehicle headlights 1. Examples of the image acquisition unit 121 include a CCD (Charged Coupled Device) camera, LiDAR (Light Detection and Ranging), millimeter-wave radar, etc.

The detection unit 122 has a similar configuration to the control unit CO, for example. The detection unit 122 performs predetermined image processing on the image acquired by the image acquisition unit 121, and detects the presence of a predetermined object, the position of the predetermined object in the image, the type of the predetermined object, etc. from the processed image. When the detection device 120 detects a predetermined object located in front of the vehicle 100, it outputs a signal indicating information such as the presence of the predetermined object, the position of the predetermined object in the image, and the type of the predetermined object to the control unit CO via the ECU (Electronic Control Unit) 101 of the vehicle 100. Furthermore, when the detection device 120 does not detect a predetermined object located in front of the vehicle 100, it outputs a signal indicating the absence of the predetermined object to the control unit CO via the ECU 101, although it is not necessary to output this signal.

Note that there are no particular limitations on the specific objects detected by the detection device 120, the number of types of specific objects, or the configuration of the detection device 120. For example, the image acquisition unit 121 may be a CCD camera and LiDAR, in which case the detection unit 122 detects the specific objects based on the images acquired by the CCD camera and LiDAR.

Next, the operation of the vehicle headlamp 1 of this embodiment will be described. In this embodiment, the operation of a pair of vehicle headlamp 1 is the same and synchronized. Therefore, the following will only describe the operation of one vehicle headlamp 1, and will omit a description of the operation of the other vehicle headlamp 1.

Figure 4 is a control flowchart for the control unit CO in this embodiment. As shown in Figure 4, the control flow includes steps SP11 to SP15.

(Step SP11)
In this step, the control unit CO changes the next step depending on whether or not a signal is input from the light switch 110. In this step, the control unit CO advances the control flow to step SP12 if a signal is input from the light switch 110, and advances the control flow to step SP15 if this signal is not input.

(Step SP12)
In this step, the control unit CO changes the next step by making a case-by-case decision depending on the signal input from the detection device 120. In this step, the control unit CO advances the control flow to step SP13 if a signal indicating the absence of a predetermined object is input from the detection device 120, and advances the control flow to step SP14 if a signal indicating information about the predetermined object is input from the detection device 120.

(Step SP13)
In this step, the control unit CO controls the lighting unit 10 so that a high beam is emitted from the vehicle headlamp 1. In this embodiment, the image generation unit 20 reads a high beam image stored in the memory ME, and the light distribution control unit 40 controls the power supply circuit 50 based on the information about the high beam image to supply power to each light-emitting element 13 of the light source unit 12. This power supply causes the light source unit 12 to emit light based on the high beam image, and light having a high beam light distribution pattern is emitted from the vehicle headlamp 1. In this way, when a predetermined object is not located in front of the vehicle 100, the vehicle headlamp 1 emits a high beam. The control unit CO then advances the control flow to step SP11.

Figure 5 is a diagram showing an example of a high beam light distribution pattern in this embodiment. In Figure 5, S represents the horizontal line, V represents the vertical line passing through the center of the vehicle 100 in the lateral direction, and the high beam light distribution pattern PH formed on a virtual vertical screen positioned 25 m in front of the vehicle 100 is shown by a thick line. In this embodiment, when emitting high beams, light is emitted from all light-emitting elements 13, and the outline of the high beam light distribution pattern is a roughly horizontally elongated rectangle. Furthermore, the hot zone, which is the area in the high beam light distribution pattern PH where the light intensity is highest, is located on or near the intersection of the horizontal line S and the vertical line V. The light intensity of the high beam light distribution pattern PH decreases as it moves away from this hot zone.

(Step SP14)
In this step, the control unit CO controls the lamp unit 10 so that the light distribution pattern of light emitted from the vehicle headlamp 1 becomes an ADB light distribution pattern corresponding to a predetermined object located in front of the vehicle 100, as detected by the detection device 120. In this embodiment, the ADB light distribution pattern is a light distribution pattern in which the light amount is changed in a first region of the high-beam light distribution pattern PH that overlaps at least a portion of the predetermined object and in a second region that follows at least a portion of the outer edge of the first region. The change in the light amount in the first region is a decrease compared to when the predetermined object is not located in front of the vehicle 100. The change in the light amount in the second region is an increase compared to when the predetermined object is not located in front of the vehicle 100. In other words, the control unit CO controls the lamp unit 10 so that the light amount in the first region of the high-beam light distribution pattern PH is decreased and the light amount in the second region is increased compared to when the predetermined object is not located in front of the vehicle 100.

When there are multiple predetermined objects located in front of the vehicle 100, a first region is provided for each predetermined object, and a second region is provided for each first region. In other words, the ADB light distribution pattern in this case is a light distribution pattern in which the amount of light in multiple first regions that overlap at least a portion of each predetermined object is reduced, and the amount of light in multiple second regions that each follow at least a portion of the outer edge of each first region is increased, within the high beam light distribution pattern PH. Furthermore, the width of each second region in a direction perpendicular to the direction in which the second region follows the outer edge of the first region varies depending on the total area of the multiple first regions. Therefore, the control unit CO controls the lamp unit 10 to emit light having such an ADB light distribution pattern. Hereinafter, the width of the second region refers to the above-mentioned width.

In this embodiment of the control, the image generation unit 20 first reads the high beam image stored in memory and processes it based on information about the specified object input from the detection device 120 to generate an ADB light distribution image representing the above-mentioned ADB light distribution pattern. Specifically, based on the information from the detection device 120, the image generation unit 20 processes the high beam image so that the pixels in the area corresponding to the above-mentioned first area become darker and the pixels in the area corresponding to the above-mentioned second area become brighter. The image generation unit 20 processes the high beam image in this way to generate an ADB light distribution image in which the brightness of part of the high beam image has been changed.

Next, based on the information of the generated ADB light distribution image, the light distribution control unit 40 controls the power supply circuit 50 to cause the light source unit 12 to emit light based on the ADB light distribution image. As a result, light having an ADB light distribution pattern corresponding to the specified object is emitted from the vehicle headlamp 1. Then, the control unit CO advances the control flow to step SP11.

Figure 6 is a diagram similar to Figure 5 showing an example of an ADB light distribution pattern in this embodiment, illustrating the ADB light distribution pattern when a retroreflective object 81, a person 82, and another vehicle 83 are located in front of the vehicle 100 as predetermined objects detected by the detection device 120. In Figure 6, the retroreflective object 81 is a road sign, the person 82 is a pedestrian, and the other vehicle 83 is a preceding vehicle. The light intensity of the first region 91a of the ADB light distribution pattern PADB that overlaps with the retroreflective object 81 is less than the light intensity of the first region 91a in the high beam light distribution pattern PH. Therefore, the vehicle headlamp 1 of this embodiment can reduce the amount of light reflected by the retroreflective object 81 and toward the vehicle 100, thereby suppressing glare to the driver caused by the reflected light. In the example shown in Figure 6, the first region 91a is rectangular and overlaps the entire retroreflective object 81. However, from the perspective of reducing glare to the driver, the first region 91a only needs to overlap at least a portion of the retroreflective object 81, and there are no restrictions on the shape or size of the first region 91a.

Furthermore, the amount of light in the first region 91b of the ADB light distribution pattern PADB that overlaps the person 82 is less than the amount of light in the first region 91b in the high beam light distribution pattern PH. Therefore, the vehicle headlamp 1 of this embodiment can reduce the amount of light irradiated onto the person 82, thereby suppressing glare to the person. In the example shown in FIG. 6, the first region 91b is rectangular and overlaps the head of the person 82, but does not overlap most of the torso of the person 82. However, from the perspective of suppressing glare to the person 82, it is sufficient for the first region 91b to overlap at least a portion of the head of the person 82, and the first region 91b may overlap the entire person 82; the shape and size of the first region 91b are not limited.

Furthermore, the light intensity of the first region 91c of the ADB light distribution pattern PADB that overlaps with the other vehicle 83 is less than the light intensity of the first region 91c in the high beam light distribution pattern PH. Therefore, the vehicle headlamp 1 of this embodiment can reduce the amount of light irradiated onto the other vehicle 83, thereby suppressing glare to the driver of the other vehicle 83. In the example shown in FIG. 6, the first region 91c is rectangular and overlaps above the license plate of the other vehicle 83. However, from the perspective of suppressing glare to the driver of the other vehicle 83, it is sufficient that the first region 91c overlaps at least a portion of the viewing area through which the driver of the other vehicle 83 sees outside the vehicle. For example, the first region 91c may overlap the entire other vehicle 83, and the shape and size of the first region 91c are not limited. Note that the visible part is, for example, the front windshield if the other vehicle 83 is an oncoming vehicle, and, if the other vehicle 83 is a leading vehicle, it is, for example, a side mirror, rear windshield, or an imaging device that captures images behind the vehicle, and these generally tend to be located above the license plate.

Furthermore, in this embodiment, the brightness of each of the first regions 91a-91c is the same, and the amount of light per unit area of the first regions 91a-91c is the same. In the example shown in FIG. 6, the area of the first region 91a is larger than the area of the first region 91b, and the area of the first region 91c is larger than the area of the first region 91a. The amount of light reduction, which is the amount of light reduced in the first region 91a, is greater than the amount of light reduction in the first region 91b, and the amount of light reduction in the first region 91c is greater than the amount of light reduction in the first region 91a.

The second region 92a is a region that follows at least a portion of the outer edge of the first region 91a. Like the second region 92a, the second region 92b is a region that follows at least a portion of the outer edge of the first region 91b, and the second region 92c is a region that follows at least a portion of the outer edge of the first region 91c. In the example shown in FIG. 6, the second regions 92a-92c extend along the entire outer edges of the first regions 91a-91c, surrounding the first regions 91a-91c. The width Wa of the first region 91a, the width Wb of the first region 91b, and the width Wc of the first region 91c are each generally constant in the direction in which the second regions 92a-92c follow the outer edges of the first regions 91a-91c, and the light intensity of each of the second regions 92a-92c is greater than the light intensity of the corresponding second region 92a-92c in the high beam light distribution pattern PH.

In this embodiment, the total light increase amount, which is the increased amount of light in these second regions 92a-92c, is the same as the total light decrease amount in the first regions 91a-91c. Furthermore, the light increase amount per unit area of these second regions 92a-92c is the same, and the widths Wa-Wc of these second regions 92a-92c are the same. The widths Wa-Wc of these second regions 92a-92c vary depending on the total area of the multiple first regions 91a-91c, and in this embodiment, the widths Wa-Wc become wider as the total area of the multiple first regions 91a-91c increases.

Figure 7 is a diagram similar to Figure 6 showing an example of an ADB light distribution pattern after a predetermined time has elapsed since the state shown in Figure 6, and shows an ADB light distribution pattern in which the total area of multiple first regions has increased from the state shown in Figure 6. In the state shown in Figure 7, a retroreflective object 81 as a predetermined object, a person 82, another vehicle 83, and another person 182, a pedestrian, are located in front of the vehicle 100. The position of the other vehicle 83 relative to the vehicle 100 in Figure 7 is generally the same as its position in Figure 6. Furthermore, the positions of the retroreflective object 81 and the person 82 relative to the vehicle 100 in Figure 7 are closer to the vehicle 100 than their positions in Figure 6. The first regions 91a-91c in the ADB light distribution pattern PADB shown in Fig. 6 change to the first regions 91a-91c in the ADB light distribution pattern PADB shown in Fig. 7, and the second regions 92a-92c in the ADB light distribution pattern PADB shown in Fig. 6 change to the second regions 92a-92c in the ADB light distribution pattern PADB shown in Fig. 7. Furthermore, the ADB light distribution pattern PADB shown in Fig. 7 includes a first region 91d that overlaps with at least a portion of another person 182, and a second region 92d that follows at least a portion of the outer edge of the first region 91d. In the example shown in Fig. 7, the second region 92d follows the entire outer edge of the first region 91d, and the width Wd of the second region 92d is generally constant in the direction in which the second region 92d follows the outer edge of the first region 91d. The light amount of the first region 91d is less than the light amount of the first region 91d in the high beam light distribution pattern PH, and the light amount of the second region 92d is greater than the light amount of the second region 92d in the high beam light distribution pattern PH. Note that, for ease of understanding, the configuration of the ADB light distribution pattern PADB shown in Figure 6 will be referred to as "before the change," and the configuration of the ADB light distribution pattern PADB shown in Figure 7 will be referred to as "after the change."

In this embodiment, the brightness of the first region 91a after the change is the same as the brightness of the first region 91a before the change, the brightness of the first region 91b after the change is the same as the brightness of the first region 91b before the change, the brightness of the first region 91c after the change is the same as the brightness of the first region 91c before the change, and the brightness of the first regions 91a, 91b, 91c, and 91d after the change are all the same. Therefore, the total amount of light reduction of the multiple first regions 91a-91d after the change is greater than the total amount of light reduction of the multiple first regions 91a-91c in the ADB light distribution pattern PADB before the change. Furthermore, the area of the first region 91a after the change is larger than the area of the first region 91a before the change, the area of the first region 91b after the change is larger than the area of the first region 91b before the change, and the area of the first region 91c after the change is approximately the same as the area of the first region 91c before the change. For this reason, the total area of the multiple first regions 91a-91d in the changed ADB light distribution pattern PADB is greater than the total area of the multiple first regions 91a-91c in the ADB light distribution pattern PADB before the change. The width Wa of the changed second region 92a is wider than the width Wa before the change, the width Wb of the changed second region 92b is wider than the width Wb before the change, and the width Wc of the changed second region 92c is wider than the width Wc before the change, and these widths Wa-Wc after the change and the width Wd of the second region 92d are the same.

Furthermore, the total amount of light reduction in the multiple first regions 91a-91d after the change is the same as the total amount of light increase in the multiple second regions 92a-92d after the change, and the amount of light increase per unit area of the multiple second regions 92a-92d after the change is the same for each other. Therefore, the amount of light increase per unit area of these second regions 92a-92d after the change is determined by the total amount of light reduction in the multiple first regions 91a-91d after the change and the post-change widths Wa-Wd, which are the same for each other.

Although not illustrated, when there is one specified object detected by the detection device 120, there will be one first region, and the second region will be one region along at least a portion of the outer edge of the first region. The greater the dimming amount of the first region, the greater the amount of dimming of the second region; in this embodiment, this is the same as the dimming amount of the first region. The greater the area of the first region, the wider the width of the second region.

In this way, when light emission is selected with the light switch 110, the vehicle headlamp 1 of this embodiment controls the light distribution of the emitted light according to the situation ahead of the vehicle 100.

(Step SP15)
In this step, the control unit CO controls the lighting unit 10 so that light is not emitted from the vehicle headlamp 1. The light distribution control unit 40 in the control unit CO controls the power supply circuit 50 to prevent light from being emitted from the lighting unit 10. As a result, light is not emitted from the vehicle headlamp 1. Then, the control unit CO advances the control flow to step SP11.

As described above, in this embodiment, when a predetermined object is not located in front of the vehicle 100, the control unit CO controls the lamp unit 10 to emit light having a high-beam light distribution pattern PH as a light distribution pattern that includes a predetermined light distribution pattern. Furthermore, when multiple predetermined objects are located in front of the vehicle 100, the control unit CO controls the lamp unit 10 so that, in the high-beam light distribution pattern PH, the amount of light in multiple first regions 91a-91d that respectively overlap at least a portion of each predetermined object is reduced and the amount of light in multiple second regions 92a-92d that respectively follow at least a portion of the outer edge of each first region 91a-91d is increased, compared to when the predetermined objects are not located in front of the vehicle 100.

For this reason, as described above, with the vehicle headlamp 1 of this embodiment, when the multiple objects located in front of the vehicle 100 include another vehicle 83 or a person 82, 182, the amount of light irradiated onto the other vehicle 83 or person 82, 182 is reduced. Therefore, the vehicle headlamp 1 of this embodiment can reduce glare on the driver of the other vehicle 83 or person 82. Furthermore, when the multiple objects located in front of the vehicle 100 include a retroreflective object 81 such as a sign, the amount of light irradiated onto the retroreflective object 81 is reduced. Therefore, the vehicle headlamp 1 of this embodiment reduces the amount of light reflected by the retroreflective object 81 and heading toward the vehicle, reducing glare on the driver of the vehicle 100 caused by the reflected light. Furthermore, the vehicle headlamp 1 of this embodiment can prevent the areas between adjacent objects from becoming darker than when one first region is provided for multiple objects. For example, as shown in FIG. 7 , the areas between the retroreflective object 81 and another vehicle 83, between the person 182 and another vehicle 83, and between the person 182 and another person 82 can be prevented from becoming darker. Furthermore, the vehicle headlamp 1 of this embodiment can prevent the areas around the first regions 91a-91d, where the amount of light is reduced, from appearing darker than when the second regions 92a-92d are not provided, thereby preventing a decrease in visibility ahead of the vehicle 100. Furthermore, in the vehicle headlamp 1 of this embodiment, the widths Wa-Wd of each of the second regions 92a-92d in a direction perpendicular to the direction along the outer edges of the first regions 91a-91d vary depending on the total area of the multiple first regions 91a-91d, and the greater this total area, the wider the widths Wa-Wd. The higher the proportion of the multiple first regions 91a-91d in the entire high beam light distribution pattern PH, the darker the high beam light distribution pattern PH tends to appear overall. Therefore, the vehicle headlamp 1 of this embodiment can prevent the high beam light distribution pattern PH from appearing dark overall.

In order to prevent the periphery of the first regions 91a-91d from appearing dark, it is preferable that the second regions 92a-92d extend along at least half of the outer edge of the first regions 91a-91d, and more preferably along the entire outer edge of the first regions 91a-91d. Furthermore, if part of the outer edge of the first regions 91a-91d also serves as part of the outer edge of the high beam light distribution pattern PH, it is preferable that the second regions 92a-92d extend along at least half of the portion of the outer edge of the first regions 91a-91d other than the portion that also serves as the outer edge of the high beam light distribution pattern PH, and it is more preferable that the second regions 92a-92d extend along the entire portion.

Furthermore, in the vehicle headlamp 1 of this embodiment, the control unit CO controls the lamp unit 10 so that the total amount of dimming of the multiple first regions 91a-91d is the same as the total amount of dimming of the multiple second regions 92a-92d. Therefore, with the vehicle headlamp 1 of this embodiment, an increase in energy consumption can be suppressed compared to when the total amount of dimming of the multiple second regions 92a-92d is greater than the total amount of dimming of the multiple first regions 91a-91d.

Furthermore, in the vehicle headlamp 1 of this embodiment, the control unit CO controls the lamp unit 10 so that the widths Wa-Wd of the multiple second regions 92a-92d are the same. Therefore, with the vehicle headlamp 1 of this embodiment, the control load on the control unit CO can be reduced compared to when the widths Wa-Wd of the multiple second regions 92a-92d are different from one another.

Furthermore, in the vehicle headlamp 1 of this embodiment, the control unit CO controls the lamp unit 10 so that the amount of light increase per unit area of the multiple second regions 92a-92d is the same. Therefore, with the vehicle headlamp 1 of this embodiment, the control load of the control unit CO can be reduced compared to when the amount of light increase per unit area of the multiple second regions 92a-92d differs from one another.

The present invention has been described above using the above embodiment as an example, but the present invention is not limited to this.

For example, in the above embodiment, the control unit CO controls the lamp unit 10 to emit light having a high-beam light distribution pattern PH when no predetermined object is located in front of the vehicle 100. However, when no predetermined object is located in front of the vehicle 100, the control unit CO simply causes the lamp unit 10 to emit light having a light distribution pattern that includes the predetermined light distribution pattern; the predetermined light distribution pattern is not limited. For example, the predetermined light distribution pattern may be an additional light distribution pattern that is added to a low-beam light distribution pattern to form a high-beam light distribution pattern. In this case, for example, the lamp unit 5 may be configured to include the lamp unit 10 and another lamp unit, and the control unit CO may emit a low beam from the other lamp unit. In this case, a portion of the additional light distribution pattern may overlap a portion of the low-beam light distribution pattern. Furthermore, the first regions 91a-91d and the second regions 92a-92d in the above embodiment may include an area of the additional light distribution pattern that overlaps with the low-beam light distribution pattern.

In the above embodiment, the first regions 91a-91d are described as having the same brightness. However, the brightness of the first regions is not limited; for example, the light intensity of the first regions may be zero. Furthermore, the brightness of at least two of the first regions may differ from one another. For example, the brightness of the first regions may differ depending on the specific object they overlap. For example, the first region 91c overlapping the other vehicle 83 may be darker than the first region 91a overlapping the retroreflective object 81. This configuration can reduce glare to the driver of the other vehicle 83 while also reducing the reduction in visibility of the retroreflective object 81. Furthermore, the first region 91a may be brighter than the first regions 91b and 91d overlapping the people 82 and 182. This configuration can reduce glare to the people 82 and 182 while also reducing the reduction in visibility of the retroreflective object 81.

In the above embodiment, the control unit CO controls the lamp unit 10 so that the width Wa-Wd of each second region 92a-92d increases as the total area of the multiple first regions 91a-91d increases. However, the control unit CO may control the lamp unit 10 so that the width Wa-Wd of each second region 92a-92d changes depending on the total area of the multiple first regions 91a-91d. For example, the control unit CO may control the lamp unit 10 so that the width Wa-Wd of each second region 92a-92d decreases as the total area of the multiple first regions 91a-91d increases. When adjacent second regions overlap, the overlapping area may become too bright, causing discomfort to the driver of the vehicle 100. Furthermore, the greater the total area of the multiple first regions, the more likely adjacent first regions and adjacent second regions tend to move closer to each other. Therefore, by using the above configuration, adjacent second regions are less likely to overlap, which can prevent the driver of the vehicle 100 from feeling uncomfortable.

In the above embodiment, the control unit CO controls the lighting unit 10 so that the widths Wa-Wd of the multiple second regions 92a-92d are the same. However, the widths Wa-Wd of the multiple second regions 92a-92d are not limited to these and may be different from each other, as long as they change depending on the total area of the multiple first regions 91a-91d. Furthermore, the widths Wa-Wd of the second regions 92a-92d do not have to be constant in the direction in which the second regions 92a-92d extend along the outer edges of the first regions 91a-91d. For example, the control unit CO may control the lighting unit 10 so that the widths Wa-Wd of the multiple second regions 92a-92d increase as the area of the first regions 91a-91d to which the second regions 92a-92d extend increases. The area that appears dark around the first regions 91a-91d tends to be larger as the area of the first regions 91a-91d increases. Therefore, this configuration can more appropriately prevent the area around the first regions 91a-91d from appearing dark. The control unit CO may also control the lamp unit 10 so that the widths Wa-Wd of the multiple second regions 92a-92d increase as the amount of dimming of the first regions 91a-91d along which the second regions 92a-92d are aligned increases. This configuration can prevent the second regions 92a-92d from becoming too bright, thereby preventing the driver of the vehicle 100 from feeling uncomfortable. Although not illustrated, the control unit CO may also control the lamp unit 10 so that the widths of the second regions decrease as the number of first regions increases. This configuration can prevent adjacent second regions from overlapping, thereby preventing the driver of the vehicle 100 from feeling uncomfortable.

In the above embodiment, the control unit CO controls the lighting unit 10 so that the sum of the light reduction amounts of the multiple first regions 91a-91d is the same as the sum of the light increase amounts of the multiple second regions 92a-92d, and so that the light increase amounts per unit area of the multiple second regions 92a-92d are the same. However, the sum of the light increase amounts of the multiple second regions 92a-92d may be different from the sum of the light reduction amounts of the multiple first regions 91a-91d, and the light increase amounts per unit area of the multiple second regions 92a-92d may be different from each other. For example, the control unit CO may control the lighting unit 10 so that the light increase amount per unit area of the multiple second regions 92a-92d increases as the light reduction amount of the first region 91a-91d along which the second region 92a-92d is located increases. This configuration can prevent the second regions 92a-92d from becoming too bright, even if the amount of brightness increase in the second regions and the amount of brightness decrease in the first regions along which the second regions are aligned are the same, thereby preventing the driver of the vehicle 100 from feeling uncomfortable. Furthermore, the control unit CO may control the lamp unit 10 so that the larger the area of the first regions 91a-91d, the greater the amount of brightness increase per unit area of the second regions 92a-92d aligned along the first regions. The surroundings of the first regions 91a-91d tend to appear darker as the area of the first regions 91a-91d increases. Therefore, this configuration can more appropriately prevent the surroundings of the first regions 91a-91d from appearing dark. Furthermore, the control unit CO may adjust the amount of brightness increase per unit area of each of the second regions 92a-92d so that the amount of brightness increase in each of the second regions and the amount of brightness decrease in the first regions along which the second regions are aligned are the same.

In addition, although not illustrated, the control unit CO may control the lamp unit 10 so that the amount of change in the width Wa-Wd of each second region 92a-92d relative to the amount of change in the total area of the multiple first regions 91a-91d decreases as the total area of the multiple first regions 91a-91d increases. As mentioned above, the greater the total area of the multiple first regions, the more adjacent second regions tend to be closer to each other. Therefore, with this configuration, adjacent second regions are less likely to overlap, compared to when the amount of change in the width of each second region relative to the amount of change in the total area of the multiple first regions is constant regardless of the total area of the multiple first regions, and this can reduce the sense of discomfort felt by the driver of the vehicle.

In addition, although not illustrated, the control unit CO may control the lamp unit 10 so that the widths Wa-Wd of the second regions 92a-92d do not change when the ratio of the sum of the areas of the first regions 91a-91d to the area of the high-beam light distribution pattern PH, which is the predetermined light distribution pattern, is equal to or less than a predetermined value. The smaller the ratio, the less likely the high-beam light distribution pattern PH will appear dark overall. Therefore, this configuration reduces the control load on the control unit CO while preventing the high-beam light distribution pattern PH from appearing dark overall. The predetermined value for the ratio is not limited, and may be, for example, between 0.1 and 0.3 when the predetermined light distribution pattern is the high-beam light distribution pattern PH.

In the above embodiment, the image generation unit 20 processes the high beam image read from the memory ME to generate an ADB light distribution image. However, the method by which the image generation unit 20 generates the ADB light distribution image is not limited. For example, the image generation unit 20 may generate an image of an area corresponding to a first area and an image of an area corresponding to a second area in the high beam image based on information from the detection device 120, and then synthesize these generated images with the high beam image to generate the ADB light distribution image. Alternatively, multiple images corresponding to the area corresponding to the first area in the high beam image, or multiple images corresponding to these images and the area corresponding to the second area, may be stored in advance in the memory ME. In this case, the image generation unit 20 may select a specific image from these images based on information from the detection device 120, and synthesize the selected image with the high beam image to generate the ADB light distribution image. The method of synthesizing such images is not limited. For example, image synthesis using a layer function may be used.

In the above embodiment, the control unit CO has an image generation unit 20 and controls the lighting unit 10 based on the ADB image generated by the image generation unit 20. However, the control unit CO does not have to have the image generation unit 20. In this case, for example, information related to the ADB light distribution pattern corresponding to a predetermined object is stored in advance in the memory ME. This information includes information related to the amount of light emitted from each light-emitting element 13 so that the light emitted from the light source unit 12 has an ADB light distribution pattern corresponding to the predetermined object. The control unit CO then references the information stored in the memory ME based on the information about the predetermined object input from the detection device 120, and controls the lighting unit 10 based on that information.

Furthermore, in the above embodiment, the light source unit 12 has been described as having a plurality of light-emitting elements 13 that can individually change the amount of light emitted. However, the light source unit 12 is not limited to this. For example, the light source unit 12 may have a DMD (Digital Mirror Device) that includes a plurality of reflective elements arranged in a matrix, and a light-emitting unit that irradiates the DMD with light. The DMD can adjust the amount of light emitted in a predetermined direction from the reflective surface of each reflective element, and can convert the light emitted in a predetermined direction from each reflective element into light based on the image generated by the image generation unit 20. In this case, the reflective surface of each reflective element can be understood to correspond to a light-emitting unit that can individually change the amount of light emitted.

In the above embodiment, the vehicle 100 is described as including a pair of vehicle headlights 1 each equipped with a control unit CO and a memory ME. However, at least one of the control unit CO and the memory ME may be shared by the pair of vehicle headlights 1. Furthermore, the signal output from the detection device 120 may be input to the control unit CO without passing through the ECU 101 of the vehicle 100. Furthermore, there are no particular limitations on the vehicle equipped with the vehicle headlight 1, the number of vehicle headlights 1 equipped on the vehicle, etc.

The present invention provides a vehicle headlamp that can suppress a decrease in visibility ahead of the vehicle, and can be used in fields such as vehicle headlamp for automobiles, etc.

DESCRIPTION OF SYMBOLS 1... Vehicle headlamp 10... Lamp unit 81, 82, 83, 182... Predetermined object 91a, 91b, 91c, 91d... First region 92a, 92b, 92c, 92d... Second region 100... Vehicle 120... Detection device CO... Control unit PH... High beam light distribution pattern Wa, Wb, Wc, Wd... Width of second region

Claims (7)

a lighting unit capable of changing the light distribution pattern of emitted light;
a control unit that receives a signal from a detection device that detects a predetermined object located in front of the vehicle and controls the lighting unit;
Equipped with
The control unit
When the predetermined object is not located in front of the vehicle, the lamp unit is controlled so as to emit light having a light distribution pattern including a predetermined light distribution pattern.
a vehicle headlamp configured to control the lighting unit so that, when a plurality of the predetermined objects are located in front of the vehicle, the amount of light in a plurality of first regions of the predetermined light distribution pattern that each overlap at least a portion of the predetermined objects decreases, the amount of light in a plurality of second regions that each extend along at least a portion of the outer edge of each of the first regions increases, and the width of each of the second regions in a direction perpendicular to the direction along the outer edge of the first region changes in accordance with the sum of the areas of the plurality of first regions, compared to when the predetermined objects are not located in front of the vehicle. 2. The vehicle headlamp according to claim 1, wherein the control unit controls the lighting unit so that a total of the dimming amounts of the first regions and a total of the dimming amounts of the second regions are equal to each other. The vehicle headlamp according to claim 1 or 2, wherein the control unit controls the lamp unit so that the widths of the second regions are the same. 3. The vehicle headlamp according to claim 1, wherein the control unit controls the lamp unit so that the second regions have the same amount of light increase per unit area. 3. The vehicle headlamp according to claim 1, wherein the control unit controls the lighting unit so that the amount of change in the width of each of the second regions relative to the amount of change in the total area of the plurality of first regions decreases as the total area of the plurality of first regions increases. 3. The vehicle headlamp according to claim 1, wherein the control unit controls the lighting unit so that the width of each of the second regions does not change when a ratio of the total area of the plurality of first regions to an area of a predetermined light distribution pattern is equal to or less than a predetermined value. 3. The vehicle headlamp according to claim 1, wherein the control unit controls the lamp unit so that the width of each of the second regions becomes narrower as the number of the first regions increases.