Vehicle headlights

Abstract

A vehicle headlamp (1) comprises: a lamp unit (10) having a plurality of light emitting elements (13); a boundary determination unit (50) for determining a boundary between a bright area to be brightened and a dark area to be darker than the bright area; and a control unit (CO). The control unit (CO) controls the lamp unit (10) so that the illuminance of light with which each irradiation spot (20) on an irradiation spot line (21) composed of irradiation spots (20) irradiated with light from the light emitting devices (13) overlapping the boundary (51) is irradiated is lower than or equal to the illuminance of light with which adjacent irradiation spots (20) on the bright area side of the irradiation spots (20) are irradiated, and is higher than or equal to the illuminance of light with which adjacent irradiation spots (20) on the dark area side of the irradiation spots (20) are irradiated, and so that the total amount of light from the lamp unit (10) with which the irradiation spot line (21) is irradiated decreases depending on the ratio of a portion of the irradiation spot line (21) that overlaps the dark area.

Description

Technical Field

[0001] The present invention relates to a vehicle headlamp.

Background Art

[0002] As a vehicle headlamp typified by an automobile headlamp, there are known ones that change the light distribution pattern of the light emitted according to other vehicles located in front of the host vehicle, or change the light distribution pattern of the light emitted according to the running state of the host vehicle such as turning. For example, the former vehicle headlamp is disclosed in Patent Document 1 below.

[0003] The vehicle headlamp described in Patent Document 1 below includes a light source unit having a plurality of light emitting portions whose light emission amounts can be individually changed, and a control unit, and the irradiation spots irradiated with the light of each light emitting portion are arranged in a matrix. Therefore, this vehicle headlamp can change the light distribution pattern of the emitted light by changing the light emission amount of the light emitted from the light emitting portion. Further, Patent Document 1 below discloses that a detection unit provided in the vehicle detects other vehicles located in front of the vehicle, and by making the illuminance of the light irradiated to the irradiation spot corresponding to the detected other vehicle zero, glare given to the driver of the other vehicle can be reduced. The light shielding region where the illuminance is zero is square.

[0004]

Patent Document 1

Summary of the Invention

[0005] In the vehicle headlight described in Patent Document 1, when the position of another vehicle relative to the vehicle changes, the light-shielding area moves or changes in size, causing a change in the light distribution pattern of the emitted light. In the vehicle headlight described in Patent Document 1, by setting the illuminance of the light illuminating a spot to zero, the spot becomes part of the light-shielding area, and by returning the illuminance of the light illuminating the spot to the illuminance it was at before it was set to zero, the spot becomes part of the unshielded area. Since the light-shielding area is rectangular, for example, when the light-shielding area moves, the row of illuminating spots touching the edge of the light-shielding area on the side of the direction of movement changes into the light-shielding area, and the row of illuminating spots forming the edge of the light-shielding area on the opposite side of the direction of movement changes into the unshielded area. Therefore, the light-shielding area moves instantaneously by the width of the illuminating spots in the direction of movement. Similarly, when the light-shielding area gets bigger or smaller, it instantly gets bigger or smaller by the width of the illuminating spots, just as when it moves. Therefore, there are concerns that the change in the light-blocking area is not smooth, and that the driver may feel uncomfortable with the change in the light distribution pattern of the emitted light.

[0006] Therefore, the present invention aims to provide a vehicle headlight that can reduce the feeling of discomfort caused by changes in the light distribution pattern of emitted light.

[0007] To achieve the above objective, the vehicle headlight of the present invention comprises a lamp unit having a plurality of light-emitting units that can individually change the amount of light emitted, and emitting light from a plurality of light-emitting units such that the illumination spots to which light is emitted from each light-emitting unit are arranged in a matrix; a boundary determination unit that determines the position of the boundary between a bright area to be brighter and a dark area to be darker than the bright area in the area that the lamp unit can illuminate; and a control unit that controls the lamp unit. The control unit controls the lamp unit such that, in an illumination spot row consisting of illumination spots that overlap the boundary, the illuminance of the light irradiated to each illumination spot in the illumination spot row is less than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the bright area side of the illumination spot, and greater than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the dark area side of the illumination spot, and the total amount of light from the lamp unit irradiated to the illumination spot row is reduced in proportion to the portion of the illumination spot row that overlaps with the dark area.

[0008] In this vehicle headlight, the light distribution pattern of the emitted light changes as the position of the boundary described above changes. Furthermore, one side of the above-described array of illumination spots is a brightened region, and the other side is a darkened region, and this array of illumination spots is located between the brightened and darkened regions. The illuminance of the light illuminating each illumination spot in such an array of illumination spots is less than or equal to the illuminance of the adjacent brightened region, and greater than or equal to the illuminance of the adjacent darkened region. Also, as described above, the total amount of light from the lamp unit illuminating the array of illumination spots decreases in proportion to the proportion of the area of ​​the array of illumination spots that should be darkened. Therefore, in this vehicle headlight, if the position of the boundary changes in such a way that this proportion increases, the array of illumination spots will gradually become a darkened region in proportion to the increase in the proportion. Conversely, if the position of the boundary changes in such a way that the proportion decreases, the array of illumination spots will gradually become a brightened region in proportion to the decrease in the proportion. Therefore, this vehicle headlight can smooth the change in the light distribution pattern of the emitted light compared to a case where the entire array of illumination spots changes from a brightened area to a darkened area, or from a darkened area to a brightened area, at a certain timing. Consequently, this vehicle headlight can reduce the feeling of unnaturalness in the light distribution pattern of the emitted light compared to the case in which the entire array of illumination spots changes at a certain timing.

[0009] The boundary determination unit may determine the position of the boundary based on information from another vehicle detection unit that detects other vehicles, such that the visibility area used by the driver of the other vehicle to see outside the vehicle overlaps with the dark area.

[0010] This vehicle headlight allows the visibility area and the darkened area to overlap, thereby suppressing glare for drivers of other vehicles. The visibility area refers to, for example, the front windshield when the other vehicle is an oncoming vehicle, and to, for example, the side mirrors, rear window, or an imaging device that captures images of the area behind the vehicle when the other vehicle is a preceding vehicle.

[0011] Alternatively, the boundary determination unit may determine the position of the boundary based on vehicle information from a driving state detection unit that detects the driving state of the vehicle, such that a predetermined area from the outer edge of the area that the lighting unit can illuminate becomes the dark area, and the control unit may control the lighting unit such that the amount of light emitted from the light emission unit corresponding to the illumination spot that overlaps only with the dark area becomes zero.

[0012] In this vehicle headlight, at least a portion of the shape of the light distribution pattern of the emitted light is approximately the same as at least a portion of the boundary described above. Therefore, with this vehicle headlight, it is possible to change the shape of the light distribution pattern of the emitted light or to change the direction of emission of light having a predetermined light distribution pattern, depending on the driving conditions of the vehicle.

[0013] When the boundary determination unit determines the boundary position based on other vehicle information, the boundary determination unit may gradually change the boundary position during the period from the first timing to the second timing immediately after the first timing, based on the boundary position information at the first timing input by the other vehicle information and the other vehicle information itself. Alternatively, the boundary determination unit may gradually change the boundary position during the period from the first timing to the second timing immediately after the first timing, based on the information of the change in the boundary position over time during a predetermined period prior to the first timing, including the first timing input by the other vehicle information and the other vehicle information itself. Furthermore, when the boundary determination unit determines the boundary position based on its own vehicle information, the boundary determination unit may gradually change the boundary position during the period from the first timing to the second timing immediately after the first timing, based on the boundary position information at the first timing input by the own vehicle information and the own vehicle information itself. Alternatively, the boundary determination unit may change the position of the boundary in steps during the period from the first timing to the second timing immediately after the first timing, based on information about the change in the position of the boundary over time during a predetermined period prior to the first timing, including the first timing into which the vehicle information is input, and the vehicle information itself.

[0014] With this configuration, the change in the light distribution pattern of the emitted light can be made smoother, and the feeling of discomfort caused by the change in the light distribution pattern can be further reduced.

[0015] The control unit may control the luminaire unit such that the illuminance of the light irradiated to at least one of the irradiation spots in the irradiation spot array is reduced in proportion to the proportion of the portion of the irradiation spot that overlaps with the dark area.

[0016] With this configuration, the change in the light distribution pattern of the emitted light can be made smoother, and the feeling of discomfort caused by the change in the light distribution pattern can be further reduced.

[0017] In this case, the control unit may control the lighting unit so that the illuminance of the light decreases in stages according to the ratio.

[0018] This configuration can reduce the computational load on the control unit.

[0019] In this case, the number of steps in the change of illuminance of the light when the position of the boundary changes so that the ratio increases may be less than the number of steps in the change of illuminance of the light when the position of the boundary changes so that the ratio decreases.

[0020] For example, when the boundary determination unit determines the boundary position based on information about other vehicles, glare to the drivers of other vehicles can be suppressed as described above. Furthermore, when the boundary position changes so that the above ratio increases, it means that the boundary position changes so that the above-mentioned illuminated spot row becomes a darkened area, and when the boundary determination unit determines the boundary position based on information about other vehicles, it means that the other vehicle is approaching the illuminated spot row. Furthermore, when the boundary position changes so that the above ratio decreases, it means that the boundary position changes so that the illuminated spot row becomes a brightened area, and when the boundary determination unit determines the boundary position based on information about other vehicles, it means that the other vehicle is moving away from the illuminated spot row. With the above configuration, for example, when the rate of change of the boundary position is constant, the time it takes for the illuminated spot row to become a darkened area can be shortened compared to the time it takes for the illuminated spot row to become a brightened area. For this reason, compared to the case where the number of steps is constant regardless of how the boundary position changes, it is possible to suppress glare to the drivers of other vehicles while suppressing an increase in the computational load of the control unit.

[0021] Furthermore, the control unit may control the lighting unit such that the illuminance of the light irradiated to some of the irradiation spots in the irradiation spot row becomes the illuminance of the light irradiated to the irradiation spot adjacent to the dark region side of the irradiation spot, and the number of irradiation spots in the irradiation spot row whose illuminance of the irradiated light becomes the illuminance of the light irradiated to the irradiation spot adjacent to the dark region side of the irradiation spot increases in proportion to the proportion of the portion of the irradiation spot row that overlaps with the dark region.

[0022] With this configuration, the computational load on the control unit can be reduced compared to the case where the illuminance of the light illuminating each irradiation spot in the irradiation spot row is lower in proportion to the proportion of the area that overlaps with the dark region of that irradiation spot.

[0023] Furthermore, the control unit may control the luminaire unit so as to form a blurred area that overlaps only with the bright area and is adjacent to the boundary, where the illuminance of the irradiated light decreases in stages as it approaches the boundary.

[0024] With this configuration, it is possible to reduce the feeling of unnaturalness regarding changes in the light distribution pattern compared to when no blurred area is formed.

[0025] In this case, the control unit may control the luminaire unit such that, when the illumination spot row is present, the total amount of light from the luminaire unit irradiating the portion of the blurred area on the brighter side of the illumination spot row is reduced in proportion to the portion of the illumination spot row that overlaps with the dark area.

[0026] In this vehicle headlamp, as the total amount of light from the lamp unit irradiated on the irradiation spot row decreases, the total amount of light from the lamp unit irradiated on the above-mentioned part also decreases. Also, as the total amount of light from the lamp unit irradiated on the irradiation spot row increases, the total amount of light from the lamp unit irradiated on the above-mentioned part also increases. Therefore, according to this vehicle headlamp, the difference between the brightness of the irradiation spot row and the brightness of the above-mentioned part can be reduced, and the sense of discomfort due to the change in the light distribution pattern can be reduced.

[0027] As described above, according to the present invention, it is possible to provide a vehicle headlamp that can reduce the sense of discomfort due to the change in the light distribution pattern of the emitted light.

Brief Description of Drawings

[0028] [Figure 1] It is a plan view conceptually showing a vehicle equipped with the vehicle headlamp in the first embodiment of the present invention. [Figure 2] It is a side view schematically showing one lamp unit shown in FIG. 1. [Figure 3] It is a front view schematically showing the light distribution pattern forming part shown in FIG. 2. [Figure 4] It is a diagram for explaining the irradiation spots irradiated with the light from each light emitting element shown in FIG. 3. [Figure 5] It is a diagram showing an example of the control flowchart of the control unit in the first embodiment. [Figure 6] It is a diagram showing the light distribution pattern of the high beam in the first embodiment. [Figure 7] It is a diagram showing an example of the boundary determined by the boundary determination unit. [Figure 8] It is a diagram showing an enlarged view of the boundary and its vicinity in FIG. 7. [Figure 9] It is a diagram showing an example of a state where the illuminance of the light irradiated on the irradiation spot decreases step by step. [Figure 10] It is a diagram showing another example of a state where the illuminance of the light irradiated on the irradiation spot decreases step by step. [Figure 11]This figure shows an example of a light distribution pattern corresponding to the boundary shown in Figure 8. [Figure 12] This figure shows an example of how the boundary changes. [Figure 13] This is a diagram illustrating the control of the lighting unit in the second embodiment. [Figure 14] This figure shows an example of a light distribution pattern in the second embodiment, similar to Figure 11. [Figure 15] This figure shows an example of a boundary determined by the boundary determination unit in the third embodiment. [Figure 16] This figure shows an example of a change in the illuminance of the light irradiated onto the spot in a modified example. [Figure 17] This figure shows another example of a change in the illuminance of the light irradiated onto the spotlight. [Modes for carrying out the invention]

[0029] The following examples illustrate embodiments for implementing the vehicle headlight according to the present invention, along with the accompanying drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified and improved from the following embodiments without departing from its spirit. Furthermore, the components of each embodiment illustrated below may be combined as appropriate. In addition, the dimensions of each component may be exaggerated in the accompanying drawings to facilitate understanding.

[0030] (First Embodiment) Figure 1 is a conceptual plan view showing a vehicle equipped with a vehicle headlight according to this embodiment. As shown in Figure 1, the vehicle 100 of this embodiment is an automobile and includes a vehicle headlight 1, a light switch 110, a vehicle detection unit 120 for detecting other vehicles located in front of the vehicle 100, a steering sensor 130, a tilt sensor 140, and a vehicle speed sensor 150.

[0031] The vehicle headlight 1 of this embodiment mainly comprises a pair of left and right lamp units 5, a control unit CO, a boundary determination unit 50, a memory ME, and a pair of power supply circuits 60. In this specification, unless otherwise specified, "right" means the right side from the driver's perspective of the vehicle 100, and "left" means the left side from the driver's perspective of the vehicle 100.

[0032] In this embodiment, the pair of lamp units 5 are shaped to be generally symmetrical with respect to each other in the left-right direction of the vehicle 100, and emit light with a changeable light distribution pattern toward the front of the vehicle 100. Furthermore, the configuration of one lamp unit 5 is the same as that of the other lamp unit 5, except that its shape is generally symmetrical. For this reason, the following description will focus on one lamp unit 5, and the description of the other lamp unit 5 will be omitted.

[0033] Figure 2 is a schematic side view showing one of the lighting fixtures 5 shown in Figure 1. As shown in Figure 2, the lighting fixture 5 mainly consists of a lighting unit 10 and a housing 16. Note that in Figure 2, the housing 16 is shown in a vertical cross-section.

[0034] The housing 16 mainly comprises a lamp housing 17, a front cover 18, and a back cover 19. The front of the lamp housing 17 is open, and the front cover 18 is fixed to the lamp housing 17 so as to close this opening. A smaller opening is formed at the rear of the lamp housing 17 than the front, and the back cover 19 is fixed to the lamp housing 17 so as to close this opening. The space formed by these lamp housing 17, front cover 18, and back cover 19 is a lamp chamber 10R, and the luminaire unit 10 is housed within this lamp chamber 10R. The luminaire unit 10 mainly comprises a light distribution pattern forming section 12 and a projection lens 15.

[0035] Figure 3 is a schematic front view showing the light distribution pattern forming unit 12 shown in Figure 2. As shown in Figures 2 and 3, the light distribution pattern forming unit 12 of this embodiment has a plurality of light-emitting elements 13 as light-emitting units that emit 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 these light-emitting elements 13 can be individually changed. In this embodiment, the light distribution pattern forming unit 12 has 64 groups of light-emitting elements, each consisting of 256 light-emitting elements 13 arranged in the horizontal direction, and these groups of light-emitting elements are arranged in the vertical direction. Furthermore, these light-emitting elements 13 are microLEDs, and the light distribution pattern forming unit 12 is a so-called microLED array. Note that the number of light-emitting elements 13 in each group of light-emitting elements and the number of groups of light-emitting elements are not particularly limited.

[0036] Such a light distribution pattern forming unit 12 can form a predetermined light distribution pattern by selecting light-emitting elements 13 to emit light. Furthermore, the light distribution pattern forming unit 12 can adjust the light intensity distribution in the predetermined light distribution pattern by adjusting the amount of light emitted from each light-emitting element 13. Therefore, the light distribution pattern forming unit 12 can form a predetermined light distribution pattern according to the amount of light emitted from multiple light-emitting elements 13.

[0037] The projection lens 15 is a lens that adjusts the divergence angle of incident light. The projection lens 15 is positioned in front of the light distribution pattern forming section 12, and light emitted from the light distribution pattern forming section 12 is incident on it, and the divergence angle of this light is adjusted by the projection lens 15. In this embodiment, the projection lens 15 is a lens in which the incident surface and the emitted surface are formed in a convex shape, and the rear focal point of the projection lens 15 is located on or near the light emitted surface of one of the light-emitting elements 13 in the light distribution pattern forming section 12. The light whose divergence angle has been adjusted by such a projection lens 15 is emitted from the lamp section 5 toward the front of the vehicle 100 via the front cover 18.

[0038] Figure 4 is a diagram illustrating the illumination spots to which light from each of the light-emitting elements 13 shown in Figure 3 is emitted. The illumination spots 20 shown in Figure 4 are the areas on a virtual vertical screen positioned 25 m in front of the vehicle 100 that are illuminated by light from the light-emitting elements 13. In Figure 4, S represents the horizontal line, and V represents the vertical line passing through the center of the vehicle 100 in the left-right direction. As described above, the multiple light-emitting elements 13 in the light distribution pattern forming unit 12 are arranged in a matrix, so the illumination spots 20 to which light from each light-emitting element 13 is emitted in front of the vehicle 100 are arranged in a matrix. For this reason, the lighting unit 10 emits light from the multiple light-emitting elements 13 so that the illumination spots 20 to which light from each light-emitting element 13 is emitted are arranged in a matrix. For ease of understanding, the number of illumination spots 20 in Figure 4 is reduced. Each illumination spot 20 corresponds to one light-emitting element 13. The relative positions of a particular light-emitting element 13 among multiple light-emitting elements 13 and the relative positions of a particular illumination spot 20 corresponding to this particular light-emitting element 13 among multiple illumination spots 20 are inverted vertically and horizontally. For example, the illumination spot 20 corresponding to a light-emitting element 13 located at the upper right end of the driver's view of the vehicle 100 is located at the lower left end of the driver's view of the vehicle 100.

[0039] In this embodiment, the illumination spots 20 are generally square in shape and adjacent to each other. The region 30 formed by all of these illumination spots 20 is a long rectangle in the left-right direction. This region 30 is the area that the luminaire unit 10 can illuminate, the vertical center of the region 30 is located on or near the horizontal line S, and the left-right center of the region 30 is located on or near the vertical line V. Adjacent illumination spots 20 may overlap each other, or they may be separated with gaps between them. However, it is preferable that the multiple illumination spots 20 are arranged in a matrix without gaps. The shape of the illumination spots 20 is not particularly limited and may be rectangular, for example. Furthermore, the multiple illumination spots 20 may include illumination spots 20 of different sizes and shapes.

[0040] Next, the control unit CO shown in Figure 1 can use, 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 an NC device is used for the control unit CO, it may or may not use a machine learning machine. As will be described later, the control unit CO controls the lighting unit 10.

[0041] In this embodiment, the light switch 110 is a switch that selects whether to emit or not emit light, and is connected to the control unit CO. When the light switch 110 is ON, it outputs a signal to the control unit CO indicating the emission of light, and when it is OFF, it does not output a signal to the control unit CO.

[0042] The other vehicle detection unit 120 of this embodiment includes a camera, a detection unit, etc. (not shown). The camera is mounted on the front of the vehicle 100 and photographs the area in front of the vehicle 100 at predetermined time intervals, for example, every 50 msec. The image captured by the camera includes at least a portion of the area 30 that can be illuminated by light emitted from a pair of lighting units 5. The detection unit detects the presence of another vehicle and the location of the other vehicle in the image captured by the camera.

[0043] When the detection unit detects another vehicle located in front of vehicle 100, it outputs a signal to the boundary determination unit 50 indicating information about the other vehicle, such as the presence of the other vehicle, an image of the other vehicle, and the position of the other vehicle in the image. In this case, the detection unit calculates the distance from vehicle 100 to the other vehicle based on the image captured by the camera. For example, if the other vehicle is an oncoming vehicle, the captured image will show a pair of white light points emitted from the headlights of the oncoming vehicle. The detection unit calculates the distance from vehicle 100 to the oncoming vehicle based on the distance between these pair of white light points and outputs a signal indicating this calculated distance to the boundary determination unit 50. Also, if the other vehicle is a preceding vehicle, the captured image will show a pair of red light points emitted from the taillights of the preceding vehicle. The detection unit calculates the distance from vehicle 100 to the preceding vehicle based on the distance between these pair of red light points and outputs a signal indicating this calculated distance to the boundary determination unit 50.

[0044] On the other hand, if the detection unit does not detect any other vehicles located in front of vehicle 100, it outputs a signal to the boundary determination unit 50 indicating that no other vehicles have been detected. As described above, the camera photographs the area in front of vehicle 100 at predetermined time intervals. Therefore, the detection unit outputs a signal indicating the above-mentioned other vehicle information or a signal indicating that no other vehicles have been detected to the boundary determination unit 50 at approximately these predetermined time intervals. Note that the detection unit does not need to output a signal to the boundary determination unit 50 if it does not detect any other vehicles.

[0045] For example, the detection unit may have a configuration similar to that of the control unit CO, and the camera may be, for example, a CCD (Charged Coupled Device) camera.

[0046] The configuration of the other vehicle detection unit 120, the method of detecting other vehicles by the other vehicle detection unit 120, the method of calculating the distance from vehicle 100 to other vehicles, and the other vehicle information output from the other vehicle detection unit 120 to the boundary determination unit 50 are not particularly limited. For example, the other vehicle detection unit 120 may further include an image processing unit that performs image processing on images captured by a camera, and the detection unit may detect the presence of other vehicles and the location of other vehicles in the captured images from the information processed by the image processing unit. In addition, the other vehicle detection unit 120 may further include a millimeter-wave radar or lidar capable of detecting objects located in front of vehicle 100. In this case, the other vehicle detection unit 120 may detect the presence of other vehicles located in front of vehicle 100, the position of said other vehicles relative to vehicle 100, and the distance from vehicle 100 to other vehicles based on the captured images obtained by the camera and information obtained by the millimeter-wave radar or lidar.

[0047] The steering sensor 130 is a driving state detection unit that detects the driving state of the vehicle 100 and is a sensor that detects the steering angle of the vehicle 100. The steering sensor 130 detects the steering angle from the rotation angle of the steering wheel of the vehicle 100, for example. The steering sensor 130 detects the steering angles, distinguishing between the right steering angle and the left steering angle as different steering angles, and outputs a signal indicating the detected steering angle, which is vehicle information, to the boundary determination unit 50.

[0048] The tilt sensor 140 is a driving state detection unit that detects the driving state of the vehicle 100, and is a sensor that detects the tilt angle of the vehicle 100 in the pitch direction. The tilt sensor 140 is, for example, a gyro sensor. This tilt sensor 140 outputs a signal indicating the detected tilt angle, which is vehicle information, to the boundary determination unit 50.

[0049] The vehicle speed sensor 150 is a driving state detection unit that detects the driving state of the vehicle 100, and is a sensor that detects the driving speed of the vehicle 100. The tilt sensor 140 detects the driving speed from, for example, the rotation speed of the tires. The vehicle speed sensor 150 outputs a signal indicating the detected driving speed, which is vehicle information, to the boundary determination unit 50.

[0050] The boundary determination unit 50 determines the position of the boundary between a bright area that should be brighter and a dark area that should be darker than the bright area in the area 30 that the lighting unit 10 can illuminate, and outputs a signal indicating the position of the boundary to the control unit CO. In this embodiment, the boundary determination unit 50 determines the position of the boundary based on information from the other vehicle detection unit 120, such that the dark area overlaps with the viewing area used by the driver of the other vehicle detected by the other vehicle detection unit 120 to see outside the vehicle. For this reason, this boundary is not predetermined. However, the boundary determination unit 50 may determine the position of the boundary by selecting from a plurality of predetermined boundary positions based on information from the other vehicle detection unit 120. Examples of viewing areas used by the driver of the other vehicle to see outside the vehicle include the front windshield when the other vehicle is an oncoming vehicle, and side mirrors, rear windows, and imaging devices that image the area behind the vehicle when the other vehicle is a preceding vehicle. It is preferable that the dark area defined by the boundary overlaps with the entirety of such a viewing area. In this embodiment, the boundary determination unit 50 determines the position of a boundary in a virtual vertical screen 30 located 25 m in front of vehicle 100, where a rectangular area overlapping with the entirety of another vehicle is to be darkened, and other areas are to be brightened. Therefore, the boundary is rectangular in shape, enclosing the entirety of the other vehicle. A predetermined gap is formed between this boundary and the outer edge of the other vehicle. The boundary determination unit 50 determines the position of such a boundary, outputs a signal indicating the boundary to the control unit CO, and stores the information of the boundary position in the memory ME, which will be described later. Therefore, the memory ME stores information on the change in the boundary position over time. The boundary determination unit 50 does not determine the position of the boundary if the distance from vehicle 100 to the other vehicle is greater than a predetermined distance, for example, 200 m or more. However, the boundary determination unit 50 may determine the position of the boundary regardless of the distance from vehicle 100 to the other vehicle 90. Furthermore, the shape of the boundary is not particularly limited. For example, the configuration of the boundary determination unit 50 may be the same as that of the control unit CO. The control unit CO may also function as the boundary determination unit 50.

[0051] One power supply circuit 60 corresponds to one luminaire unit 5, and the other power supply circuit 60 corresponds to the other luminaire unit 5. Each power supply circuit 60 includes a driver, and when a signal is input from the control unit CO, this driver adjusts the power supplied to each light-emitting element 13 of the luminaire unit 10. In this way, the amount of light emitted from each light-emitting element 13 is adjusted. In this embodiment, the amount of light emitted from each light-emitting element 13 is adjusted by the driver of the power supply circuit 60 adjusting the power supplied to each light-emitting element 13 by PWM (Pulse Width Modulation) control. However, the method of adjusting the amount of light emitted from each light-emitting element 13 is not particularly limited.

[0052] Memory ME is configured to store information and to allow the stored information to be read. Memory ME is, for example, a non-transitory recording medium, and semiconductor recording media such as RAM (Random Access Memory) and ROM (Read Only Memory) are preferred, but it can also include any form of recording medium such as optical recording media and magnetic recording media. Note that "non-transitory" recording media includes all computer-readable recording media except transient propagation signals, and does not exclude volatile recording media.

[0053] The memory ME of this embodiment stores information regarding the power supplied to each light-emitting element 13 when the high beam is emitted.

[0054] Next, the operation of the vehicle headlight 1 of this embodiment will be described. Specifically, the operation of changing the light distribution pattern of the emitted light in accordance with other vehicles detected by the other vehicle detection unit 120 will be described. Figure 5 is a diagram showing an example of a control flowchart of the control unit CO in this embodiment. As shown in Figure 5, the control flow of this embodiment includes steps SP11 to SP15.

[0055] (Step SP11) In this step, the control unit CO determines whether or not a signal is input from the light switch 110. If this signal is input to the control unit CO, the control unit CO proceeds to step SP12. On the other hand, if this signal is not input to the control unit CO, the control unit CO proceeds to step SP15. Therefore, the control unit CO's determination can be understood as changing the next step depending on the input signal.

[0056] (Step SP12) In this step, the control unit CO determines whether the boundary position has been determined by the boundary determination unit 50 based on the signal input from the boundary determination unit 50. If this signal is not input to the control unit CO, the control unit CO proceeds to step SP13 of the control flow. On the other hand, if this signal is input to the control unit CO, the control unit CO proceeds to step SP14 of the control flow.

[0057] (Step SP13) In this step, the control unit CO controls the lighting unit 10 so that a high beam is emitted from the vehicle headlight 1. Specifically, the control unit CO refers to the information stored in the memory ME and outputs a control signal to the power supply circuit 60 based on the power supplied to each light-emitting element 13 when the high beam is emitted. Based on this signal, the power supply circuit 60 supplies power to each light-emitting element 13 from a power supply (not shown). As a result, a high beam is emitted from the vehicle headlight 1. Then, the control unit CO returns the control flow to step SP11.

[0058] Figure 6 shows the high beam light distribution pattern in this embodiment. In Figure 6, S represents a horizontal line, V represents a vertical line passing through the center of the vehicle 100 in the left-right 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 the high beam is emitted, light is emitted from all light-emitting elements 13. Therefore, the outline of the high beam light distribution pattern matches the outline of region 30. Also, the hot zone, which is the region with the highest light intensity in the high beam light distribution pattern PH, is located on or near the intersection of the horizontal line S and the vertical line V. The light intensity in the high beam light distribution pattern PH decreases as you move away from this hot zone. Therefore, the light-emitting elements 13 are controlled so that the light intensity distribution is as described.

[0059] (Step SP14) In this step, the control unit CO controls the luminaire unit 10 so that the light distribution pattern of the light emitted from the vehicle headlight 1 corresponds to the light distribution pattern corresponding to the boundary position determined by the boundary determination unit 50. Then, the control unit CO returns the control flow to step SP11.

[0060] Figure 7 shows an example of the boundary position determined by the boundary determination unit 50, and is a diagram showing an example of the boundary position determined when another vehicle 90, an oncoming vehicle, is detected by the other vehicle detection unit 120. Figure 8 is a magnified view of the boundary 51 and its vicinity in Figure 7. In Figure 7, S represents a horizontal line, V represents a vertical line passing through the center of the vehicle 100 in the left-right direction, the boundary 51 on a virtual vertical screen placed 25m in front of the vehicle 100 is shown as a thick line, and the illumination spots 20 are shown as dashed lines. For ease of understanding, the number of illumination spots 20 is reduced in Figures 7 and 8.

[0061] As described above, in this embodiment, the boundary 51 is rectangular in shape, enclosing the entirety of the oncoming vehicle 90. The area inside the boundary 51 is the dark region to be darkened, and the area outside the boundary 51 is the bright region to be illuminated. Therefore, the dark region to be darkened overlaps with the front windshield, which serves as the viewing area for the driver of the oncoming vehicle 90 to see outside. Based on the signal indicating this boundary 51 input from the boundary determination unit 50, the control unit CO controls the luminaire unit 10 so that the illuminance of the light emitted from the luminaire unit 10 in the illumination spot 20 that overlaps only with the dark region to be darkened is lower than the illuminance of the light emitted from the luminaire unit 10 in the illumination spot 20 that overlaps only with the bright region to be illuminated. Specifically, the control unit CO controls the light-emitting element 13 that illuminates the illumination spot 20 that overlaps only with the dark region so that the amount of light emitted from the light-emitting element 13 becomes zero. Furthermore, the control unit CO controls the light-emitting element 13 so that the amount of light emitted from the light-emitting element 13, which irradiates the irradiation spot 20 that overlaps only with the bright region, is equal to the amount of light emitted when the high beam is emitted.

[0062] Furthermore, as shown in Figure 8, if there is a series of illumination spots 21 consisting of illumination spots 20 that overlap with the boundary 51, the control unit CO controls the luminaire unit 10 so that the total amount of light from the luminaire unit 10 irradiating the series of illumination spots 21 is reduced in proportion to the proportion of the portion 22 that overlaps with the dark region in the series of illumination spots 21. In Figure 8, the series of illumination spots 21 is shown with a thick line, and the dark region to be darkened is hatched with diagonal lines. In this embodiment, the control unit CO controls the luminaire unit 10 so that the illuminance of the light irradiating each illumination spot 20 of the series of illumination spots 21 is gradually reduced in proportion to the proportion of the portion 22 that overlaps with the dark region in the illumination spot 20. The illuminance of the light irradiating each illumination spot 20 of the series of illumination spots 21 is less than or equal to the illuminance of the light irradiating the illumination spot 20 adjacent to the bright region side of the illumination spot 20, and greater than or equal to the illuminance of the light irradiating the illumination spot 20 adjacent to the dark region side of the illumination spot 20.

[0063] Figure 9 shows an example of a state in which the illuminance of the light illuminating the illumination spot 20 decreases in stages. Figure 10 shows another example of a state in which the illuminance of the light illuminating the illumination spot 20 decreases in stages. In Figures 9 and 10, the illumination spots 20 that are not hatched are illumination spots 20 that overlap only with the bright region, and the amount of light emitted corresponds to the light-emitting element 13, which is the amount of light emitted when the high beam is emitted. Also, the illumination spots 20 that are hatched with diagonal lines are illumination spots 20 that overlap only with the dark region, and the amount of light emitted corresponds to the light-emitting element 13, which is zero. Also, the illumination spots 20 that are hatched with multiple dots are illumination spots 20 that constitute the illumination spot row 21, and the multiple dots in the hatching in Figure 10 are finer than those in Figure 9. The illuminance of the light illuminating the illumination spot 20 is lower the finer the dots in the hatching. Furthermore, the proportion of the area 22 overlapping with the dark region in the irradiation spot row 21 in Figure 9 is 25%, while the proportion of the area 22 overlapping with the dark region in the irradiation spot row 21 in Figure 10 is 75%. In this embodiment, if the proportion of the area 22 overlapping with the dark region in the irradiation spot row 21 is less than 50%, the control unit CO controls the light-emitting element 13 that irradiates each irradiation spot 20 of the irradiation spot row 21 to a predetermined amount less than the amount of light emitted when the high beam is emitted, as shown in Figure 9. The amount of light emitted from these light-emitting elements 13 is assumed to be the same, but may be different. Also, if the above proportion is 50% or more, the control unit CO controls the light-emitting element 13 that irradiates each irradiation spot 20 of the irradiation spot row 21 to a predetermined amount less than the amount of light in the state shown in Figure 9, as shown in Figure 10. Therefore, in this embodiment, the illuminance of the light irradiated to each irradiation spot 20 of the irradiation spot row 21 is reduced in two stages according to the above ratio.

[0064] As the lighting unit 10 is controlled by the control unit CO, a light distribution pattern 200 is formed in which the area 210 overlapping with the illumination spot 20 that overlaps with the dark area in the high beam light distribution pattern PH is darkened, as shown in Figure 11. This darkened area 210 overlaps with the front windshield, which serves as the viewing area for other vehicles 90. Figure 11 is a diagram showing an example of a light distribution pattern corresponding to the boundary 51 shown in Figure 8. In Figure 11, S represents a horizontal line, V represents a vertical line passing through the center of the vehicle 100 in the left-right direction, and the light distribution pattern 200 on a virtual vertical screen placed 25m in front of the vehicle 100 is shown by a thick line.

[0065] (Step SP15) In this step, no signal is input from the light switch 110 to the control unit CO. Therefore, the light switch 110 is off. The control unit CO controls the lighting unit 10 so that no light is emitted from the lighting unit 10, thereby preventing light from being emitted from the vehicle headlight 1. Then, the control flow returns to step SP11.

[0066] Thus, in the vehicle headlight 1 of this embodiment, the light distribution pattern PH of the emitted high beam changes to a light distribution pattern 200 having a darkened region 210 when the position of the boundary 51 is determined by the boundary determination unit 50. Furthermore, this darkened region 210 changes as the position of the boundary 51 changes.

[0067] Figure 12 is a diagram illustrating an example of how a boundary changes, specifically an example of how the boundary changes by moving in the left-right direction. In this embodiment, as shown in Figure 12, the boundary determination unit 50 changes the position of the boundary in steps if the position of boundary 51c, which is determined based on other vehicle information input from the other vehicle detection unit 120 at a certain first timing, differs from the position of boundary 51a at this first timing. This change in the position of the boundary occurs during the period from the first timing to the second timing, immediately after the first timing, when other vehicle information is input from the other vehicle detection unit 120. In other words, the boundary determination unit 50 in this embodiment changes the position of the boundary in steps during the period from the first timing to the second timing, based on the information of the position of boundary 51a at the first timing and the other vehicle information input at the first timing. In the example shown in Figure 12, the boundary changes from boundary 51a to boundary 51b and then to boundary 51c, but the number of steps in the change is not particularly limited. Furthermore, the way in which the boundary changes in steps is not particularly limited. For example, if the boundary changes in a way that causes it to move, the position of the boundary may be changed in steps so that the boundary moves at a roughly constant speed. Alternatively, if the boundary changes in a way that causes it to deform, the position of the boundary may be changed in steps so that the shape of the boundary approaches the shape of the deformed boundary at a roughly constant rate.

[0068] Furthermore, the control flow of the control unit CO is not particularly limited. Also, in this embodiment, the steering sensor 130, the tilt sensor 140, and the vehicle speed sensor 150 do not need to output signals to the boundary determination unit 50.

[0069] As described above, the vehicle headlight 1 of this embodiment comprises a lamp unit 10, a boundary determination unit 50, and a control unit CO. The lamp unit 10 has a plurality of light-emitting elements 13 whose light intensity can be individually changed, and emits light from the plurality of light-emitting elements 13 such that the illumination spots 20 illuminated by the light from each of the light-emitting elements 13 are arranged in a matrix. The boundary determination unit 50 determines the position of the boundary 51 between a bright area that should be brighter and a dark area that should be darker than the bright area in the area 30 that the lamp unit 10 can illuminate. The control unit CO controls the lamp unit 10 based on the position of the boundary 51. Therefore, in the vehicle headlight 1 of this embodiment, the light distribution pattern of the emitted light changes as the boundary 51 changes.

[0070] Furthermore, the control unit CO controls the luminaire unit 10 so that, in the illumination spot row 21 consisting of illumination spots 20 that overlap with the boundary 51, the illuminance of the light irradiated to each illumination spot 20 in the illumination spot row 21 is less than or equal to the illuminance of the light irradiated to the illumination spot 20 adjacent to the bright area side of the illumination spot 20, and greater than or equal to the illuminance of the light irradiated to the illumination spot 20 adjacent to the dark area side of the illumination spot 20. The control unit CO also controls the luminaire unit 10 so that the total amount of light from the luminaire unit 10 irradiating the illumination spot row 21 is reduced in proportion to the proportion of the portion 22 that overlaps with the dark area in the illumination spot row 21. One side of the illumination spot row 21 is a brightened area, and the other side is a darkened area, and this illumination spot row 21 is located between the brightened area and the darkened area. The illuminance of the light irradiated to each illumination spot 20 in such an illumination spot row 21 is less than or equal to the illuminance of the adjacent brightened area, and greater than or equal to the illuminance of the adjacent darkened area. Furthermore, as described above, the total amount of light from the lamp unit 10 illuminating the illumination spot row 21 decreases in proportion to the proportion of the portion 22 that overlaps with the dark area to be darkened in the illumination spot row 21. For this reason, in the vehicle headlight 1 of this embodiment, if the position of the boundary 51 changes so that this proportion increases, the illumination spot row 21 becomes a region that is gradually darkened in proportion to the increase in proportion. Conversely, if the position of the boundary 51 changes so that this proportion decreases, the illumination spot row becomes a region that is gradually brightened in proportion to the decrease in proportion. For this reason, the vehicle headlight 1 of this embodiment can make the change in the light distribution pattern of the emitted light smoother compared to the case in which the entire illumination spot row 21 changes from a region that is brightened to a region that is darkened, or from a region that is darkened to a region that is brightened, at a certain timing. Accordingly, the vehicle headlight 1 of this embodiment can reduce the feeling of unnaturalness in the light distribution pattern of the emitted light compared to the case in this embodiment.

[0071] Furthermore, in the vehicle headlight 1 of this embodiment, the boundary determination unit 50 determines the position of the boundary 51 based on information from the other vehicle detection unit 120 that detects other vehicles 90, so that the visibility area for the driver of the other vehicle 90 to see outside the vehicle and the dark area overlap. According to the vehicle headlight 1 of this embodiment, the visibility area and the darkened area can be made to overlap, and glare given to the driver of the other vehicle 90 can be suppressed.

[0072] Furthermore, in the vehicle headlight 1 of this embodiment, the boundary determination unit 50 gradually changes the position of the boundary 51 during the period from the first timing to the second timing immediately after the first timing when other vehicle information is input from the other vehicle detection unit 120, based on the information about the position of the boundary at the first timing when other vehicle information is input from the other vehicle detection unit 120 and the other vehicle information input at the first timing. Therefore, the vehicle headlight 1 of this embodiment can make the change in the light distribution pattern of the emitted light smoother and reduce the feeling of discomfort caused by the change in the light distribution pattern.

[0073] Furthermore, from the viewpoint of making the change in the light distribution pattern of the emitted light smoother, the boundary determination unit 50 may change the boundary 51 as follows. In this embodiment, as described above, the memory ME stores information on the change in the position of the boundary 51 over time. For this reason, the boundary determination unit 50 may change the position of the boundary 51 in steps during the period from the first timing to the second timing immediately after the first timing when information on other vehicles from the other vehicle detection unit 120 is input, based on the information on the change in the position of the boundary 51 over time during a predetermined period before the first timing, including the first timing when information on other vehicles from the other vehicle detection unit 120 is input, and the information on other vehicles from the other vehicle detection unit 120 input at the first timing. Even with such a configuration, the change in the light distribution pattern of the emitted light can be made smoother. Also, with such a configuration, for example, if the change in the position of the boundary over time is such that the boundary moves with a predetermined acceleration, the position of the boundary can be changed in steps so that the boundary moves at a speed corresponding to that acceleration. Therefore, with this configuration, the position of the boundary can be changed in stages in response to the change in the position of the boundary over time, and the change in the light distribution pattern of the emitted light can be made smoother. The boundary determination unit 50 may predict the position of the boundary at the second timing based on the information of the change in the position of the boundary 51 over time and the information of other vehicles from the other vehicle detection unit 120 input at the first timing, and may change the position of the boundary in stages during the period from the first timing to the second timing based on the information of the change in the position of the boundary 51 over time and the predicted position of the boundary.

[0074] Furthermore, in the vehicle headlight 1 of this embodiment, the control unit CO controls the lamp unit 10 so that the illuminance of the light irradiated to each illumination spot 20 of the illumination spot row 21 decreases in stages according to the proportion of the portion 22 that overlaps with the dark area in the illumination spot 20.Therefore, the vehicle headlight 1 of this embodiment can make the change in the light distribution pattern of the emitted light smoother and reduce the feeling of discomfort from the change in the light distribution pattern.In addition, the vehicle headlight 1 of this embodiment can reduce the computational load of the control unit CO compared to the case in which the illuminance of the light decreases continuously according to the above proportion.The number of stages in which the illuminance decreases according to the above proportion is not particularly limited, but from the viewpoint of reducing the computational load of the control unit CO, it is preferable that it be 16 or less.The number of stages may also differ depending on whether the position of the boundary 51 changes so that the above proportion increases or so that the position of the boundary 51 changes so that the above proportion decreases.For example, the number of stages when the position of the boundary 51 changes so that the above proportion increases may be less than when the position of the boundary 51 changes so that the above proportion decreases. When the position of boundary 51 changes so that the above ratio increases, it means that the position of boundary 51 changes so that the illuminated spot row 21 becomes a darkened region. Conversely, when the position of boundary 51 changes so that the above ratio decreases, it means that the position of boundary 51 changes so that the illuminated spot row 21 becomes a brightened region. Therefore, with this configuration, for example, when the rate of change of the position of boundary 51 is constant, the time it takes for the illuminated spot row 21 to become a darkened region can be made shorter than the time it takes for the illuminated spot row 21 to become a brightened region. Therefore, compared to the case where the number of steps is constant regardless of how the position of boundary 51 changes, it is possible to suppress the increase in the computational load of the control unit CO while suppressing the glare given to the driver of other vehicles 90.

[0075] (Second Embodiment) Next, a second embodiment of the present invention will be described in detail. Note that components identical or equivalent to those in the first embodiment are denoted by the same reference numerals unless otherwise specified, and redundant descriptions are omitted. In this embodiment, the light distribution pattern of the emitted light when the position of the boundary 51 is determined differs from that of the first embodiment.

[0076] Figure 13 is a diagram illustrating the control of the luminaire unit 10 in this embodiment, and shows the vicinity of the boundary 51 and the illumination spots 20 near the boundary 51 in the same manner as in Figure 8. The control unit CO in this embodiment controls the luminaire unit 10 so that a blurred region is formed which overlaps with the bright region and is adjacent to the boundary 51, and in which the illuminance of the illuminated light decreases in stages as it approaches the boundary 51. Specifically, in Figure 13, the light-emitting element 13 that illuminates the illumination spot group 25, which consists of illumination spots 20 with hatching made up of multiple dots, is controlled so that the group of illumination spots 25 becomes a blurred region. The illumination spots 20 of this illumination spot group 25 are multiple rows of illumination spots 20 that overlap only with the bright region and are arranged along the boundary 51. The illuminance of the light irradiated onto the illumination spots 20 of the illumination spot group 25 is lower than the illuminance of the light irradiated onto the illumination spots 20 when the high beam is emitted. Furthermore, in the multiple illumination spots 20 arranged perpendicular to the boundary 51, the illuminance of the light irradiated to the illumination spot 20 located on the boundary 51 side is lower than the illuminance of the light irradiated to the illumination spot 20 located on the opposite side of the boundary 51. The control unit CO also controls the light-emitting element 13 so that the amount of light emitted from the light-emitting element 13 that irradiates illumination spots 20 that overlap only with the bright regions other than the illumination spots 20 of the illumination spot group 25 is equal to the amount of light emitted when a high beam is emitted. In addition, similar to the first embodiment, the control unit CO also controls the light-emitting element 13 so that the amount of light emitted from the light-emitting element 13 that irradiates illumination spots 20 that overlap only with the dark regions is zero.

[0077] As the lighting unit 10 is controlled by the control unit CO in this manner, as shown in Figure 14, in the high beam light distribution pattern PH, the area 310 overlapping with the illumination spot 20 that overlaps with the dark area is darkened, and the light intensity in the area 320 overlapping with the illumination spot group 25 is gradually reduced as it approaches area 310, forming a light distribution pattern 300. Area 310 overlaps with the front windshield, which is the visible area of ​​the other vehicle 90. Area 320 is the blurred area mentioned above and extends along the outer edge of area 310. Note that Figure 14 is a diagram showing an example of the light distribution pattern in this embodiment, similar to Figure 11, and is an example of a light distribution pattern corresponding to the boundary 51 shown in Figure 8.

[0078] According to the vehicle headlight 1 of this embodiment, the feeling of discomfort due to changes in the light distribution pattern can be reduced compared to when the above-mentioned blurred area is not formed.

[0079] Furthermore, as shown in Figure 13, the control unit CO of this embodiment controls the lamp unit 10 so that, when there is a row of illumination spots 21, the total amount of light from the lamp unit 10 illuminating the area 26 on the brighter side of the row of illumination spots 21 in the blurred area decreases in proportion to the proportion of the area 22 that overlaps with the dark area of ​​the row of illumination spots 21. In Figure 13, the area 26 on the brighter side of the row of illumination spots 21 in the blurred area is enclosed by a dashed line. In the vehicle headlight 1 of this embodiment, as the total amount of light from the lamp unit 10 illuminating the row of illumination spots 21 decreases, the total amount of light from the lamp unit 10 illuminating area 26 also decreases. Conversely, as the total amount of light from the lamp unit 10 illuminating the row of illumination spots 21 increases, the total amount of light from the lamp unit 10 illuminating area 26 increases. Therefore, the difference between the brightness of the row of illumination spots 21 and the brightness of area 26 can be reduced, and the feeling of discomfort due to changes in the light distribution pattern can be reduced.

[0080] Furthermore, the width W in the direction perpendicular to the boundary 51 in the blurred area described above is not particularly limited, and this width W does not have to be constant. This width W may change according to the proportion of the portion 22 that overlaps with the dark area in the illumination spot row 21.

[0081] (Third embodiment) Next, a third embodiment of the present invention will be described in detail. Note that components identical or equivalent to those in the first embodiment are denoted by the same reference numerals unless otherwise specified, and redundant descriptions are omitted. In this embodiment, the position of the boundary 51 determined by the boundary determination unit 50 differs from that in the first embodiment.

[0082] In this embodiment, the boundary determination unit 50 determines the position of the boundary 51 based on vehicle information from the steering sensor 130, tilt sensor 140, and vehicle speed sensor 150, which are driving state detection units that detect the driving state of the vehicle, so that a predetermined area from the outer edge of the area 30 that the lighting unit 10 can illuminate becomes a dark area.

[0083] Figure 15 is a diagram showing an example of the boundary position determined by the boundary determination unit 50 of this embodiment, and is similar to Figure 7 in showing an example of the boundary position determined when the steering angle and tilt angle are zero and the vehicle speed is below a predetermined speed.

[0084] In this embodiment, the boundary 51 corresponds to the outer shape of the light distribution pattern emitted from the vehicle headlight 1, and is a long rectangle in the left-right direction, corresponding to the outer shape of the high beam light distribution pattern, and is separated from the outer edge of the region 30. The region from the outer edge of region 30 to the boundary 51 is the dark region that should be darkened, and the area inside the boundary 51 is the bright region that should be brightened. The boundary determination unit 50 moves the position of the entire boundary 51 in the left-right direction by a predetermined distance according to the steering angle. This predetermined distance according to the steering angle is the distance from the position of the boundary 51 shown in Figure 15, and is the distance to the left when the steering angle is to the left, and the distance to the right when the steering angle is to the right. Furthermore, this predetermined distance according to the steering angle is shorter when the steering angle is small and longer when the steering angle is large, and in this embodiment, it becomes progressively longer as the steering angle increases. The boundary determination unit 50 also moves the position of the entire boundary 51 in the up-down direction by a predetermined distance according to the inclination angle. The predetermined distance corresponding to this inclination angle is the distance relative to the position of the boundary 51 shown in Figure 15. If the inclination angle is upward, it is the distance in the downward direction, and if the inclination angle is downward, it is the distance in the upward direction. Furthermore, this predetermined distance corresponding to the inclination angle is shorter when the inclination angle is small and longer when the inclination angle is large. In this embodiment, it increases in stages as the inclination angle increases. In addition, if the vehicle speed exceeds a predetermined speed, for example 60 km / h, the boundary determination unit 50 changes the position of the boundary 51 so that the width of the boundary 51 in the left-right direction becomes about 4 / 5.

[0085] In this embodiment, the control unit CO controls the light-emitting element 13 that illuminates the illumination spot 20 overlapping only with the dark area so that the amount of light emitted from the light-emitting element 13 becomes zero. The control unit CO also controls the light-emitting element 13 that illuminates the illumination spot 20 overlapping only with the bright area so that the illuminance of the area consisting of the illumination spot 20 overlapping only with the bright area decreases as you move away from the center of the area. As a result, the shape of the light distribution pattern of the light emitted from the vehicle headlight 1 of this embodiment is approximately the same as the boundary 51. Furthermore, with the vehicle headlight of this embodiment, when the driving speed of the vehicle 100 exceeds a predetermined speed, the shape of the light distribution pattern can be changed so that the width of the light distribution pattern in the left-right direction becomes smaller. As a result, with the vehicle headlight of this embodiment, the driver's line of sight during high-speed driving can be more easily concentrated near the center of the front of the vehicle, improving visibility of distant objects. Furthermore, according to the vehicle headlight of this embodiment, the direction of emission of a predetermined light distribution pattern can be changed according to the steering angle and tilt angle of the vehicle 100. Therefore, according to the vehicle headlight of this embodiment, light can be emitted ahead of the vehicle on a curved road, and even if the vehicle 100 is tilted in the pitch direction, light can be emitted in the appropriate direction. Accordingly, according to the vehicle headlight 1 of this embodiment, visibility in the direction of travel can be improved compared to when the direction of light emission does not change according to the steering angle and tilt angle of the vehicle 100.

[0086] Although the present invention has been described above with reference to the above embodiments, the present invention is not limited to these.

[0087] For example, in the above embodiment, the control unit CO was described as controlling the luminaire unit 10 so that the illuminance of the light irradiated to each illumination spot 20 of the illumination spot row 21 decreases in stages according to the proportion of the area 22 that overlaps with the dark region in the illumination spot 20. However, the control unit CO only needs to control the luminaire unit 10 so that the total amount of light from the luminaire unit 10 irradiating the illumination spot row 21 decreases according to the proportion of the area 22 that overlaps with the dark region in the illumination spot row 21. For example, the control unit CO may control the luminaire unit 10 so that the illuminance of the light irradiated to each illumination spot 20 of the illumination spot row 21 decreases continuously according to the proportion of the area 22 that overlaps with the dark region in the illumination spot 20. Alternatively, the control unit CO may control the luminaire unit 10 so that the illuminance of the light irradiated to at least one illumination spot 20 in the illumination spot row 21 decreases in stages according to the proportion of the area 22 that overlaps with the dark region in the illumination spot 20. Furthermore, the control unit CO may control the luminaire unit 10 as shown in the modified examples described below.

[0088] Figure 16 shows an example of a state in which the illuminance of the light irradiating the illumination spot 20 changes in a modified example, and Figure 17 shows another example of a state in which the illuminance of the light irradiating the illumination spot 20 changes in a modified example. In Figures 16 and 17, the illumination spots 20 that are not hatched correspond to the illumination spots 20 that emit light from the light-emitting element 13, which is the light-emitting element when emitting a high beam. The illumination spots 20 that are hatched with diagonal lines correspond to the illumination spots 20 that emit light from the light-emitting element 13, which is zero. In Figure 16, the percentage of the area 22 that overlaps with the dark region in the illumination spot row 21 is 25%, and in Figure 17, the percentage of the area 22 that overlaps with the dark region in the illumination spot row 21 is 75%. The control unit CO of this modified example controls the luminaire unit 10 so that the illuminance of the light irradiating some of the illumination spots 20 in the illumination spot row 21 becomes the illuminance of the light irradiating the illumination spot 20 adjacent to the dark region side of that illumination spot. Furthermore, in this modified example, the control unit CO controls the luminaire unit so that the number of illumination spots 20 in the illumination spot row 21 whose illuminance of the emitted light is equal to the illuminance of the illumination spot 20 adjacent to the dark area side of the illumination spot 20 increases, according to the proportion of the portion 22 in the illumination spot row 21 that overlaps with the dark area. Specifically, if the proportion of the portion 22 in the illumination spot row 21 that overlaps with the dark area is less than 50%, the control unit CO controls the light-emitting element 13 so that the amount of light emitted from the light-emitting element 13 that illuminates some of the illumination spots 20 in the illumination spot row 21 becomes zero, as shown in Figure 16. Also, if the above proportion is 50% or more, the control unit CO controls the light-emitting element 13 so that the number of light-emitting element 13 that emit zero light is greater than when the above proportion is less than 50%, as shown in Figure 17. In this modified example, according to the above ratio, the illuminance of the light emitted from each irradiation spot 20 is equal to the illuminance of the light emitted from the irradiation spot 20 adjacent to the dark area, starting from the irradiation spot 20 located at one end of the irradiation spot row 21. However, the order in which the illuminance of the light emitted from each irradiation spot 20 is equal to the illuminance of the light emitted from the irradiation spot 20 adjacent to the dark area is not particularly limited.For example, the illuminance of the light emitted from the illumination spots 20 located in the center of the illumination spot row 21 may be the same as the illuminance of the light emitted from the illumination spots 20 adjacent to the dark area. Alternatively, the control unit CO may control the luminaire unit 10 such that the illuminance of the light emitted from some of the illumination spots 20 in the illumination spot row 21 decreases in stages according to the proportion of the area of ​​the illumination spot 20 that overlaps with the dark area, and the number of illumination spots 20 in the illumination spot row 21 whose illuminance of the light emitted is the same as the illuminance of the light emitted from the illumination spot 20 adjacent to the dark area of ​​the illumination spot 20 increases according to the proportion of the area of ​​the illumination spot row 21 that overlaps with the dark area.

[0089] Furthermore, in the first and second embodiments, the amount of light emitted from the light-emitting element 13 that illuminates the illumination spot 20 overlapping only with the dark region was set to zero. However, it is sufficient that the illuminance of the light illuminating the illumination spot 20 overlapping only with the dark region is lower than the illuminance of the light illuminating the illumination spot 20 overlapping only with the bright region. Therefore, the amount of light emitted from the light-emitting element 13 that illuminates the illumination spot 20 overlapping only with the dark region does not have to be zero.

[0090] Furthermore, in the third embodiment, a boundary determination unit 50 that determines the position of the boundary 51 based on vehicle information from the steering sensor 130, tilt sensor 140, and vehicle speed sensor 150, which are driving state detection units, was described as an example. However, the boundary determination unit 50 only needs to determine the position of the boundary 51 based on vehicle information from the driving state detection unit that detects the driving state of the vehicle 100. For example, the boundary determination unit 50 may determine the boundary 51 based on vehicle information from at least one of the steering sensor 130, tilt sensor 140, and vehicle speed sensor 150.

[0091] Furthermore, in the third embodiment, a boundary determination unit 50 that determines the position of the boundary 51 corresponding to the outer shape of the high beam light distribution pattern was described as an example. However, the boundary determination unit 50 only needs to determine the position of the boundary 51 such that a predetermined area from the outer edge of the area 30 that the luminaire unit 10 can illuminate becomes a dark area. With such a configuration, at least a part of the outer shape of the light distribution pattern of the emitted light will be approximately the same as at least a part of the boundary described above. Therefore, with such a configuration, it is possible to change the outer shape of the light distribution pattern of the emitted light or to change the direction of emission of light having a predetermined light distribution pattern depending on the driving state of the vehicle. For this reason, the boundary determination unit 50 may, for example, determine the position of the boundary 51 corresponding to the outer shape of the low beam light distribution pattern. Also, the shape of the boundary 51 is not particularly limited, and the boundary 51 may be connected to the outer edge of the area 30.

[0092] Furthermore, the above embodiments can be combined as appropriate. For example, the first embodiment and the third embodiment may be combined, and the boundary determination unit 50 in the first embodiment may determine the position of the boundary in the first embodiment and the position of the boundary in the second embodiment. With such a configuration, it is possible to change the shape of the light distribution pattern of the emitted light or to change the direction of emission of light having a predetermined light distribution pattern, while suppressing glare given to the drivers of other vehicles. In addition, in the third embodiment, the control unit CO may control the luminaire unit 10 so that the blurred area shown in the second embodiment is formed. Also, in the third embodiment, the number of steps in which the illuminance of the light irradiated to each irradiation spot 20 of the irradiation spot row 21 decreases in steps according to the proportion of the portion 22 that overlaps with the dark area in the irradiation spot 20 is not particularly limited. As mentioned above, this number of steps may differ depending on whether the position of the boundary 51 changes so that the above proportion increases or so that the position of the boundary 51 changes so that the above proportion decreases. For example, the number of steps in the case where the position of boundary 51 changes so that the above-mentioned ratio increases may be less than the number of steps in the case where the position of boundary 51 changes so that the above-mentioned ratio decreases.

[0093] Furthermore, in the above embodiment, a lighting unit 10 was described as having a light distribution pattern forming unit 12 having a plurality of light-emitting elements 13 whose light intensity can be individually changed. However, the lighting unit 10 may have a plurality of light-emitting units whose light intensity can be individually changed, and the light from the plurality of light-emitting units should be emitted such that the illumination spots irradiated by the light from each light-emitting unit are arranged in a matrix. For example, the lighting unit 10 may have a light distribution pattern forming unit having a DMD (Digital Mirror Device) including a plurality of reflective elements arranged in a matrix, and a light source unit that irradiates the DMD with light. The DMD can adjust the light intensity emitted from the reflective surface of each reflective element in a predetermined direction, and the illumination spots irradiated by the light emitted from each reflective element in a predetermined direction are arranged in a matrix. For this reason, it can be understood that the reflective surface of each reflective element corresponds to the above light-emitting unit.

[0094] Furthermore, in the above embodiment, a lighting unit 5 comprising one lighting unit 10 was described as an example. However, the lighting unit 5 may further comprise another lighting unit separate from the lighting unit 10, and the vehicle headlight 1 may form a predetermined light distribution pattern by the light emitted from the lighting unit 10 and the light emitted from the other lighting unit. In this case, the configuration of the other lighting unit is not particularly limited, and for example, it may have the same configuration as the lighting unit 10.

[0095] According to the present invention, a vehicle headlight is provided that can reduce the feeling of discomfort caused by changes in the light distribution pattern of emitted light, and can be used in fields such as vehicle headlights for automobiles.

Claims

1. A lighting unit having multiple light-emitting sections that can individually change the amount of light emitted, and emitting light from multiple light-emitting sections such that the illumination spots illuminated by the light from each of the light-emitting sections are arranged in a matrix, A boundary determination unit that determines the position of the boundary between a bright region that should be made brighter and a dark region that should be made darker than the bright region in the area that the light fixture unit can illuminate, A control unit for controlling the aforementioned lighting unit, Equipped with, The control unit controls the luminaire unit such that, in a row of illumination spots consisting of illumination spots overlapping the boundary, the illuminance of the light irradiated to each illumination spot in the row of illumination spots is less than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the bright area side of the illumination spot, and greater than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the dark area side of the illumination spot, and the total amount of light from the luminaire unit irradiating the row of illumination spots decreases in proportion to the proportion of the area overlapping with the dark area in the row of illumination spots, and the illuminance of the light irradiated to at least one illumination spot in the row of illumination spots decreases in stages in proportion to the proportion of the area overlapping with the dark area in the illumination spot. When the position of the boundary changes so that the proportion of the area overlapping with the dark region in the illumination spot increases, the number of steps in the change of illuminance of the light is less than the number of steps in the change of illuminance of the light when the position of the boundary changes so that the proportion decreases. A vehicle headlight characterized by the following features.

2. A lighting unit having multiple light-emitting sections that can individually change the amount of light emitted, and emitting light from multiple light-emitting sections such that the illumination spots illuminated by the light from each of the light-emitting sections are arranged in a matrix, A boundary determination unit that determines the position of the boundary between a bright region that should be made brighter and a dark region that should be made darker than the bright region in the area that the light fixture unit can illuminate, A control unit for controlling the aforementioned lighting unit, Equipped with, The control unit controls the luminaire unit such that, in the array of illumination spots consisting of illumination spots overlapping the boundary, the illuminance of the light irradiated to each illumination spot in the array of illumination spots is less than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the bright area side of the illumination spot, and greater than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the dark area side of the illumination spot, and the total amount of light from the luminaire unit irradiating the array of illumination spots decreases in proportion to the portion of the array of illumination spots that overlaps with the dark area, and a blurred area is formed that overlaps only with the bright area and is adjacent to the boundary, where the illuminance of the irradiated light decreases in stages as it approaches the boundary. A vehicle headlight characterized by the following features.

3. The control unit controls the luminaire unit such that, when the illumination spot row is present, the total amount of light from the luminaire unit irradiating the portion of the blurred area on the brighter side of the illumination spot row is reduced in proportion to the portion of the illumination spot row that overlaps with the darker area. The vehicle headlight according to feature 2.

4. The boundary determination unit determines the position of the boundary based on information about other vehicles from the other vehicle detection unit that detects other vehicles, such that the visibility area for the driver of the other vehicle to see outside the vehicle overlaps with the dark area. A vehicle headlight according to any one of claims 1 to 3.

5. The boundary determination unit determines the position of the boundary based on vehicle information from a driving state detection unit that detects the driving state of the vehicle, such that a predetermined area from the outer edge of the area that the lighting unit can illuminate becomes the dark area. The control unit controls the luminaire unit so that the amount of light emitted from the light emitter corresponding to the illumination spot that overlaps only with the dark region becomes zero. A vehicle headlight according to any one of claims 1 to 3.

6. The boundary determination unit, based on the information of the boundary position at the first timing in which the other vehicle information is input and the other vehicle information itself, gradually changes the position of the boundary during the period from the first timing to the second timing in which the other vehicle information is input immediately after the first timing. The vehicle headlight according to feature 4.

7. The boundary determination unit, based on the information of the boundary position at the first timing input by the vehicle itself and the vehicle itself, gradually changes the position of the boundary during the period from the first timing to the second timing input by the vehicle itself immediately after the first timing. The vehicle headlight according to feature 5.

8. The boundary determination unit, based on information about the time-dependent change in the boundary position during a predetermined period prior to the first timing in which the other vehicle information is input, and the other vehicle information, gradually changes the boundary position during the period from the first timing to the second timing in which the other vehicle information is input immediately after the first timing. The vehicle headlight according to feature 4.

9. The boundary determination unit, based on information about the time-dependent change in the boundary position during a predetermined period prior to the first timing in which the vehicle information is input, and the vehicle information itself, gradually changes the boundary position during the period from the first timing to the second timing in which the vehicle information is input immediately after the first timing. The vehicle headlight according to feature 5.

10. A lighting unit having multiple light-emitting sections that can individually change the amount of light emitted, and emitting light from multiple light-emitting sections such that the illumination spots illuminated by the light from each of the light-emitting sections are arranged in a matrix, A boundary determination unit that determines the position of the boundary between a bright region that should be made brighter and a dark region that should be made darker than the bright region in the area that the light fixture unit can illuminate, A control unit for controlling the aforementioned lighting unit, Equipped with, The control unit controls the luminaire unit such that, in a row of illumination spots consisting of illumination spots overlapping the boundary, the illuminance of the light irradiated to each illumination spot in the row of illumination spots is less than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the bright area side of the illumination spot, and greater than or equal to the illuminance of the light irradiated to the illumination spot adjacent to the dark area side of the illumination spot, and the total amount of light from the luminaire unit irradiating the row of illumination spots is reduced in proportion to the portion of the row of illumination spots that overlaps with the dark area. The boundary determination unit determines the position of the boundary based on information about other vehicles from the other vehicle detection unit that detects other vehicles, such that the visibility area for the driver of the other vehicle to see outside the vehicle overlaps with the dark area, and based on the information about the position of the boundary at the first timing in which the other vehicle information is input and the other vehicle information, it gradually changes the position of the boundary during the period from the first timing to the second timing in which the other vehicle information is input immediately after the first timing. A vehicle headlight characterized by the following features.

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