JP7605664B2 - Vehicle lighting control device, vehicle lighting control method, and vehicle lighting system - Google Patents

Description

This disclosure relates to a vehicle lighting control device and control method, and a vehicle lighting system.

A light distribution control technology is known that sets a light illumination range and a dimming range (or a non-illumination range) according to the positions of preceding vehicles and oncoming vehicles ahead of the vehicle and illuminates the area ahead of the vehicle (see, for example, JP 2020-26248 A). This type of light distribution control technology is also called ADB (Adaptive Driving Beam) control, and contributes to improving visibility ahead of the vehicle.

However, when the left-right position of a preceding vehicle, etc., as seen from the vehicle's own vehicle changes due to, for example, the preceding vehicle changing lanes or the approach of an oncoming vehicle, if the speed of the preceding vehicle's movement in the left-right direction is high, the control of the light illumination range and dimming range may not be able to keep up, and the preceding vehicle, etc. may be temporarily dazzled by glare.

JP 2020-26248 A

One of the objectives of the specific embodiment of the present disclosure is to reduce the possibility of causing glare to preceding and oncoming vehicles.

A vehicle lighting system according to one aspect of the present disclosure includes:
A vehicle lamp;
A control device for causing the vehicle lamp to form an illumination light having a light distribution pattern according to the position of a vehicle ahead ;
A vehicle lighting system comprising :
the control device sets a dimming range and a light irradiation range in response to the position of the vehicle ahead, and sets an extended dimming range to the left or right of the dimming range in response to the moving direction of the vehicle ahead in the vehicle width direction, and generates a control signal to cause the vehicle lamp to form irradiation light of a light distribution pattern including the dimming range, the light irradiation range, and the extended dimming range;
the brightness of the irradiated light corresponding to each of the light irradiation range, the dimming range, and the expanded dimming range is set by increasing or decreasing the brightness of the irradiated light for each of a plurality of segments divided in the vehicle width direction,
a width of the expanded dimming range is set to be relatively large when a moving speed of the forward vehicle in a vehicle width direction is relatively large, and is set to be relatively small when the moving speed is relatively small;
The brightness of the extended dimming range is set so that a portion close to the dimming range is relatively dark and a portion far from the dimming range is relatively bright ,
a gradual change time for the brightness of the segment corresponding to the expanded dimming range, which is a time required for changing the brightness from a state before the change to a set brightness, is set to be relatively shorter as the moving speed is faster and to be relatively longer as the moving speed is slower;
The plurality of segments include at least one or more first segments having a relatively small width, one or more second segments having a larger width than the first segments, and one or more third segments having a larger width than the second segments;
The gradual-change time corresponding to the first segment is corrected to be shorter than the gradual-change time corresponding to the second segment, and the gradual-change time corresponding to the third segment is corrected to be longer than the gradual-change time corresponding to the second segment.
A vehicle lighting system .

The above configuration makes it possible to reduce the possibility of causing glare to preceding and oncoming vehicles.

FIG. 1 is a block diagram showing a configuration of a vehicle lighting system according to an embodiment. FIG. 2 is a diagram for explaining the angular velocity when the forward vehicle moves in the left and right direction. FIG. 3 is a diagram illustrating an example of the configuration of an ADB unit. FIG. 4 is a diagram illustrating an example of the configuration of a computer system that realizes the controller. 5A to 5C are diagrams for explaining the outline of the operation of the vehicle lighting system. FIG. 6 is a diagram illustrating an example of the relationship between the angular velocity and the width of the expanded dimming range, and the relationship between the angular velocity and the gradual change time. FIG. 7 is a diagram showing an example of the configuration of segments, which are regions whose brightness can be individually controlled to form a light distribution pattern. FIG. 8 is a diagram for explaining the segment width conditions in each region and the correction value of the gradual change time in each region. FIG. 9 is a flowchart showing an overall operation procedure of the vehicle lighting system. FIG. 10 is a flowchart showing a detailed operation procedure of step S14 shown in FIG. FIG. 11 is a flowchart showing the operation procedure of timer monitoring executed in conjunction with the operation shown in FIG. 12A and 12B are diagrams for explaining an example of light distribution control by a vehicle lighting system. 13A and 13B are diagrams for explaining an example of light distribution control by a vehicle lighting system. 14A and 14B are diagrams for explaining an example of light distribution control by a vehicle lighting system.

Figure 1 is a block diagram showing the configuration of a vehicle lighting system according to one embodiment. The vehicle lighting system shown in the figure includes an image capture device 10, a controller 11, and a pair of headlights (vehicle lighting) 12L and 12R.

The imaging device 10 captures an image of the space ahead of the vehicle and generates an image of the captured image. The imaging device 10 also performs a predetermined image recognition process on the captured image to detect features of a preceding vehicle or an oncoming vehicle (e.g., the positions of headlights and taillights). The imaging device 10 is installed, for example, above the inside of the windshield of the vehicle. The imaging device 10 is configured to include, for example, a camera that generates an image and an image processor that performs image recognition processing on the image.

The controller 11 controls the operation of the pair of headlights 12L, 12R. This controller 11 has, as functional blocks, a vehicle position acquisition unit 20, an angular velocity calculation unit 21, a light distribution pattern setting unit 22, and a control signal generation unit 23. As shown in FIG. 4 described below, the controller 11 is realized by using a computer system having, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and executing a predetermined operation program in this computer system. This controller 11 corresponds to the "control device."

The vehicle position acquisition unit 20 acquires a signal or data indicating the position of the vehicle ahead from the imaging device 10. The vehicle ahead here is, for example, an oncoming vehicle or a leading vehicle. The position of the vehicle ahead is represented, for example, by a relative angle based on the vehicle's own position (the position of the imaging device 10).

The angular velocity calculation unit 21 calculates the angular velocity as a physical quantity that indicates the moving speed, which is the amount of movement per unit time in the left-right direction (vehicle width direction) of the vehicle ahead. The method of calculating the angular velocity will be described in detail later.

The light distribution pattern setting unit 22 sets a light distribution pattern including a light irradiation range, which is a range other than the dimming range (or non-illumination range) that corresponds to the position of the vehicle ahead acquired by the vehicle position acquisition unit 20, for the high beam irradiable range. The light distribution pattern setting unit 22 also sets an extended dimming range to the left or right of the dimming range depending on the moving direction of the vehicle ahead. The light distribution pattern setting unit 22 also sets the light irradiation range, dimming range, and extended dimming range taking into account the moving direction of the vehicle ahead and the angular velocity during movement, and sets the brightness of the irradiated light corresponding to each range and the time required for the brightness to change.

The control signal generating unit 23 generates a control signal corresponding to the light distribution pattern set by the light distribution pattern setting unit 22 and supplies it to the ADB unit 31 of each headlamp 12L, 12R. The control signal generating unit 23 also generates a control signal corresponding to the brightness of the low beam and supplies it to the low beam unit 30 of each headlamp 12L, 12R.

Each headlamp 12L, 12R is provided on the left and right sides of the front of the vehicle, and is used to illuminate the area ahead of the vehicle. Each headlamp 12L, 12R has a low beam unit 30 and an ADB unit 31.

The low beam unit 30 has, for example, a light source bulb and a reflector, and operates in response to a control signal from the controller 11. The light emitted from the light source bulb is reflected by the reflector, and part of this reflected light is blocked by a light blocking plate, thereby generating light for forming a low beam that mainly illuminates an area relatively close to the vehicle.

The ADB unit 31 operates upon receiving a control signal from the controller 11 and generates light for forming a high beam that mainly illuminates an area relatively far from the vehicle. The high beam in this embodiment is controlled by the ADB control described above. As such an ADB unit 31, for example, an ADB unit using a liquid crystal element as exemplified in FIG. 3 described later can be used. Note that, as the ADB unit 31, various types of ADB units can be used, such as an ADB unit of a type that forms a light distribution pattern by arranging multiple LEDs and selectively turning on/off the LEDs, and an ADB unit of a type that forms a light distribution pattern by scanning light from a laser element with a movable reflector and turning the laser element on and off at high speed.

2 is a diagram for explaining the angular velocity when the forward vehicle moves in the left-right direction. In FIG. 2, the state of the vehicle itself 100 and the forward vehicle 102 observed from above is shown. Note that here, a preceding vehicle is shown as an example of the forward vehicle 102, but the same applies to an oncoming vehicle. As shown in the figure, the relative position of the forward vehicle 102 can be expressed, for example, by an angle based on a predetermined position 101 of the vehicle itself 100. Here, the predetermined position 101 is, for example, the installation position of the imaging device 10 in this embodiment, and generally corresponds to the center of the vehicle 100 in the vehicle width direction. In addition, the position of the forward vehicle 102 can be determined, for example, corresponding to the center of the vehicle width direction of the forward vehicle 102. For example, if the information about the forward vehicle 102 obtained from the imaging device 10 is the relative angle of the positions of the left and right taillights or headlights of the forward vehicle 102, the average value of these left and right angles may be set as the angle corresponding to the position of the forward vehicle 102. Alternatively, the relative angle of the position of the taillight or headlight on either the left or right side of the vehicle ahead 102 may be used as is, or an angle indicating a specific position of the vehicle ahead 102 (for example, the position of the license plate) may be used. Then, the angular velocity as the moving speed of the vehicle ahead 102 can be obtained by dividing the moving angle θc, which is the amount of change in the position of the vehicle ahead 102 in a specified time, by the specified time. The angular velocity calculation unit 21 obtains the angular velocity corresponding to the moving speed of the vehicle ahead 102 in the left-right direction in the above manner.

Figure 3 is a diagram showing an example of the configuration of an ADB unit. The ADB unit 31 shown in Figure 3 is configured to include a light source 150, a liquid crystal element 151, a pair of polarizing plates 152a and 152b, and a projection lens 153.

The light source 150 is configured to include a white light LED that is configured by combining a light emitting element (LED) that emits blue light with a yellow phosphor. The light source 150 includes, for example, a plurality of white light LEDs arranged in a matrix or line. In addition to LEDs, light sources commonly used for vehicles, such as lasers, light bulbs, and discharge lamps, can be used as the light source 150. Other optical systems (for example, lenses, reflectors, or combinations thereof) may be present on the path from the light source 150 to the liquid crystal element 151.

The liquid crystal element 151 has, for example, a number of pixel sections (light modulation regions) that can each be controlled individually, and the transmittance of each pixel section is set variably according to the magnitude of the voltage applied to the liquid crystal layer given by a driver (not shown) that operates in response to a control signal from the controller 11. Light from the light source 150 enters this liquid crystal element 151 and passes through it, forming an image with brightness and darkness corresponding to the above-mentioned light irradiation range, dimming range, and extended dimming range. In addition, by variably setting the time for changing the transmittance of each pixel section, the gradual change time described below can be controlled.

The pair of polarizing plates 152a, 152b are arranged facing each other with the liquid crystal element 151 sandwiched between them, with their polarization axes, for example, approximately perpendicular to each other. Each of the polarizing plates 152a, 152b may be, for example, an absorption type polarizing plate made of a general organic material (iodine-based, dye-based). In addition, if heat resistance is important, it is also preferable to use a wire grid type polarizing plate. Also, an absorption type polarizing plate and a wire grid type polarizing plate may be used in a stacked manner.

The projection lens 153 expands the image (a light-dark image) formed by the light passing through the liquid crystal element 151 so as to provide a light distribution for the headlights, and projects it forward of the vehicle. An appropriately designed lens is used for the projection lens 153. In this embodiment, an inverted projection type projector lens is used.

FIG. 4 is a diagram showing an example of the configuration of a computer system that realizes a controller. The illustrated computer system includes a CPU 201, a ROM 202, a RAM 203, a storage device 204, and an external interface (I/F) 205, all of which are connected to each other so as to be able to communicate with each other. The CPU 201 operates based on a basic control program read from the ROM 202, and realizes the functions of the controller 11 described above by reading and executing a program (application program) 206 stored in the storage device 204. The RAM 203 temporarily stores data to be used during the operation of the CPU 201. The storage device 204 is a non-volatile data storage device such as a hard disk or SSD (Solid State Drive), and stores various data such as the program 206. The external interface 205 is an interface that connects the CPU 201 to an external device, and is used to connect, for example, the imaging device 10 to the CPU 201.

Figures 5(A) to 5(C) are diagrams for explaining the general operation of the vehicle lighting system. Each diagram shows a schematic view of the space ahead of the vehicle. Note that, although a preceding vehicle is shown here as an example of the vehicle ahead 102, the vehicle ahead 102 may also be an oncoming vehicle.

As shown in FIG. 5(A), the basic operation of the vehicle lighting system is to form a light distribution pattern including a dimming range 250 corresponding to the position of the vehicle 102 ahead, and other light irradiation ranges 251, 252. The dimming range 250 is set to a width at least equal to or wider than the width of the vehicle 102 ahead, depending on the position of the vehicle 102 ahead. The light irradiation ranges 251, 252 are provided on the left and right of the dimming range 250. The light distribution pattern is formed by the ADB unit 31, whose operation is controlled by the controller 11.

Also, as shown in FIG. 5B, when the position of the forward vehicle 102 in the left-right direction (vehicle width direction) changes, the positions and widths of the dimming range 250 and the light irradiation ranges 251 and 252 are changed according to the changed position. At this time, a dimming range 253 is added to the right or left side (the side corresponding to the moving direction of the forward vehicle 102) of the dimming range 250 according to the moving direction and moving speed (angular velocity) of the forward vehicle 102 in the left-right direction. In the following description, this added dimming range is called the "extended dimming range". The extended dimming range 253 is a dimming range that does not overlap with the forward vehicle 102 and is extended in the moving direction of the forward vehicle 102, and its width is set variably according to the magnitude of the angular velocity, which is the degree of position change of the forward vehicle 102. Specifically, the larger the angular velocity, the larger the width of the extended dimming range 253 is set. When the forward vehicle 102 has essentially stopped moving (when the angular velocity has stabilized below a certain value), the expanded dimming range 253 is released and changed to part of the light irradiation range 251 (or 252) as shown in FIG. 5(C).

The extended dimming range 253 is a preliminary dimming range that is provided in anticipation of a case where the setting (changing) of the dimming range 250 cannot be completed in time to accommodate the left-right movement of the vehicle 102 ahead. The extended dimming range 253 is formed in a gradation such that the side closer to the vehicle 102 ahead is darker (i.e., the degree of dimming is greater) and the side farther from the vehicle 102 ahead is brighter (i.e., the degree of dimming is smaller). Such brightness (degree of dimming) adjustment is achieved by increasing or decreasing the transmittance of the transmitted light by optical modulation for each region by the liquid crystal element 151 described above.

By using such a gradation-like light distribution pattern, it is possible to reduce the glare given to the vehicle 102 ahead, even if the vehicle 102 ahead moves suddenly. Also, even if the vehicle 102 ahead frequently changes its position due to swaying, for example, part of the shading range 250 switches to part of the extended dimming range 253 (a relatively dark part), so there is less change in the amount of light (illuminance) compared to when part of the shading range 250 switches to part of the light irradiation range 251 (or 252). This reduces the sense of discomfort given to the driver of the vehicle itself and the vehicle 102 ahead.

Figure 6 is a diagram illustrating the relationship between the angular velocity and the width of the expanded dimming range, and the relationship between the angular velocity and the gradual change time. As described above, the width of the expanded dimming range (hereinafter referred to as "gradation width") is set according to the angular velocity as the moving speed in the left-right direction of the vehicle ahead, with the gradation width being set larger as the angular velocity increases. Here, the gradation width is expressed as an angle based on the position of the vehicle itself. For example, when the angular velocity n is 2.0 rad/s or more, it is preferable to set the gradation width D to 2.0 deg. Also, when the angular velocity n is 1.5 rad/s or more and less than 2.0 rad/s, it is preferable to set the gradation width D to 1.5 deg. Also, when the angular velocity n is less than 1.5 rad/s, it is preferable to set the gradation width D to 1.0 deg.

Note that these are just examples, and the numerical conditions can be adjusted as appropriate. The gradation width may also be set to change continuously according to the angular velocity. In this way, by variably setting the gradation width according to the angular velocity, it is possible to more reliably prevent glare by widening the gradation width when the vehicle ahead moves significantly to the left or right, and on the other hand, to narrow the gradation width when the vehicle ahead moves less, thereby increasing the light irradiation range and improving forward visibility. In other words, it is possible to set an appropriate gradation width according to the behavior of the vehicle ahead.

The gradual change time is set to a shorter time as the angular velocity increases. Here, "gradual change time" refers to the time required for the brightness (illuminance) of the part set in the expanded dimming range to change from its previous state. In many cases, the state before being set in the expanded dimming range is the dimming range, and in that case the gradual change time is the time required to change from a state corresponding to the dimming range (for example, 0 illuminance or a state equivalent thereto) to a state corresponding to the expanded dimming range.

For example, if the angular velocity n is 2.0 rad/s or more, it is preferable to set the gradual change time to 400 ms. Furthermore, if the angular velocity n is 1.5 rad/s or more and less than 2.0 rad/s, it is preferable to set the gradual change time to 600 ms. Furthermore, if the angular velocity n is less than 1.5 rad/s, it is preferable to set the gradual change time to 800 ms. Note that this is only an example, and the numerical conditions can be adjusted as appropriate. Furthermore, the gradual change time may be set to change continuously according to the angular velocity.

In this way, by variably setting the gradual change time according to the angular velocity, it is possible to more reliably prevent glare by quickly forming the expanded dimming range in preparation for large left/right movement of the vehicle ahead. On the other hand, by slowly forming the expanded dimming range in preparation for small movement of the vehicle ahead, the decrease in illuminance in this range can be delayed, improving forward visibility. In other words, it is possible to set an appropriate gradual change time according to the behavior of the vehicle ahead.

Figure 7 is a diagram showing an example of the configuration of segments, which are regions whose brightness can be individually controlled to form a light distribution pattern. Here, the segments are shown formed on a screen when a screen is assumed to be at a predetermined position (e.g., several tens of meters ahead) in front of the vehicle. A region (narrow region) R1 of constant width on the left and right sides including the center o in front of the vehicle contains a plurality of relatively small segments 301 (20 segments in the illustrated example). A region (medium region) R2 of constant width provided on the left and right sides of region R1 each contains a plurality of segments 302 (7 segments each in the illustrated example) that are wider than segment 301. Segment 301 corresponds to the "first segment" and segment 302 corresponds to the "second segment."

Regions (wide areas) R3 of constant width provided on the left and right sides of region R2 each contain a number of segments 303, 304 (three segments each in the illustrated example) that are wider than segments 301, 302. Each of the two segments 303 is narrower than each of the segments 304. Each of the segments 301, 302, 303, 304 is arranged in the left-right direction in the figure, and is set so that the width (segment width) of the segments in the region closer to the center o becomes smaller. Segments 303 and 304 correspond to the "third segment."

In the region R1, the segment width of each segment 301 is set to be equal, and in the region R2, the segment width of each segment 302 is set to be equal, but the width of each segment may be set to a different size even within each region. For example, by making the segment width smaller the closer to the center o, it is possible to more precisely control the light distribution pattern in front of the vehicle or in the region close to it.

Figure 8 is a diagram for explaining the segment width conditions in each region and the correction value of the gradual change time in each region. Here, the segment width S is expressed as an angle based on the position of the vehicle. For example, it is preferable to set the segment width of each segment 301 included in region R1 to be smaller than 0.5 degrees. It is also preferable to set the segment width of each segment 302 included in region R2 to be equal to or greater than 0.5 degrees and less than 0.9 degrees. It is also preferable to set the segment width of each segment 303, 304 included in region R3 to be equal to or greater than 0.9 degrees. Note that this is just an example, and the numerical conditions can be adjusted as appropriate.

In addition, it is preferable to correct the length of the gradual change time set variably according to the angular velocity for each segment belonging to each of the regions R1 to R3. For example, for each segment 301 belonging to region R1, it is preferable to correct the gradual change time T set according to the angular velocity by multiplying it by 0.8, and use the corrected gradual change time. For each segment 302 belonging to region R2, it is preferable to use 1.0 times the gradual change time T set according to the angular velocity, that is, the value as it is. For each segment 303, 304 belonging to region R3, it is preferable to correct the gradual change time T set according to the angular velocity by multiplying it by 1.2, and use the corrected gradual change time. By performing such correction, it is possible to change the brightness more quickly for each segment 301 with a relatively small width belonging to region R1, thereby further reducing the possibility of causing glare to a vehicle ahead, and it is possible to mitigate the sudden change in brightness for each segment 303, 304 with a relatively large width belonging to region R3, thereby further reducing the possibility of causing discomfort to the driver of the vehicle itself and the vehicle ahead.

Figure 9 is a flowchart showing the overall operation procedure of the vehicle lighting system. Figure 10 is a flowchart showing the detailed operation procedure of step S14 shown in Figure 9. Figure 11 is a flowchart showing the operation procedure of timer monitoring executed in conjunction with the operation shown in Figure 10. Note that for each operation procedure, the order of each processing step can be changed or other processing steps can be added as long as no contradiction or inconsistency occurs in the results, and such aspects are not excluded.

First, the overall operation procedure will be described with reference to FIG.
The vehicle position acquisition unit 20 of the controller 11 acquires the position of the vehicle ahead from the imaging device 10 (step S11). The light distribution pattern setting unit 22 sets a light irradiation range and a dimming range according to the acquired position of the vehicle ahead, and the control signal generating unit 23 generates a control signal corresponding to the light irradiation range and the dimming range and supplies the control signal to the ADB unit 31 of each headlamp 12L, 12R. As a result, illumination light according to a light distribution pattern according to the position of the vehicle ahead is formed in front of the vehicle (step S12).

In addition, in step S12, the light distribution pattern setting unit 22 sets the gradual change time required to change the brightness (illuminance) of the part that was previously in the dimming range and has been changed to the light irradiation range to a brightness corresponding to the light irradiation range. Here, for example, this is set to 1000 ms for each of the regions R1 to R3. The control signal generating unit 23 generates a control signal so that the brightness of the emitted light changes according to this set gradual change time, and supplies this to the ADB unit 31 of each headlamp 12L, 12R. As a result, the brightness of the part that has been changed to the light irradiation range changes according to the gradual change time (step S13).

The light distribution pattern setting unit 22 sets the extended dimming range according to the angular velocity calculated by the angular velocity calculation unit 21, and sets the gradual change time of each segment included in the extended dimming range. The control signal generation unit 23 generates a control signal so that the brightness of the irradiated light changes according to the set gradual change time, and supplies the control signal to the ADB unit 31 of each headlamp 12L, 12R. As a result, each segment of the extended dimming range changes in brightness according to the gradual change time (step S14).

The detailed operation procedure of step S14 will be described with reference to FIG.
The angular velocity calculation unit 21 calculates an angular velocity as the lateral moving speed of the forward vehicle based on the position of the forward vehicle acquired by the vehicle position acquisition unit 20 (step S21).

If the angular velocity is greater than a certain value, i.e., if the vehicle ahead is deemed to be moving in the left-right direction (step S22; NO), the light distribution pattern setting unit 22 sets the width (gradation width) of the expanded dimming range and the gradual change time according to the angular velocity (step S23). In addition, the light distribution pattern setting unit 22 corrects the gradual change time for each segment included in the expanded dimming range according to the region to which each segment belongs (step S24). The specific setting and correction methods for the gradation width and gradual change time are as described above.

The light distribution pattern setting unit 22 also stops the timer monitoring operation by a timer (not shown) for timing the end of the gradation light distribution in the expanded dimming range (step S25).

The control signal generating unit 23 generates a control signal corresponding to the gradual change time for each segment set and corrected by the light distribution pattern setting unit 22, and supplies the control signal to the ADB unit 31 of each headlamp 12L, 12R. This causes gradation light distribution control of the extended dimming range to be performed (step S26). Then, the process returns to step S21.

On the other hand, if the angular velocity is equal to or less than a certain value, i.e., if it is deemed that the vehicle ahead is not moving to the left or right (step S22; YES), the light distribution pattern setting unit 22 causes a timer (not shown) to execute a timer monitoring operation for timing the end time of the gradation light distribution (step S27). If the timer is already running, it is allowed to continue.

If the end time of the gradation control has not arrived (step S28; NO), the process returns to step S21. If the end time of the gradation control has arrived, the light distribution pattern setting unit 22 changes the expanded dimming range to the light irradiation range. The gradual brightness change time at this time is set to, for example, 1000 ms.

The control signal generating unit 23 generates a control signal corresponding to the gradual change time for each segment set by the light distribution pattern setting unit 22, and supplies the control signal to the ADB unit 31 of each headlamp 12L, 12R. As a result, the gradation light distribution control of the expanded dimming range is released, and this range is changed to the light irradiation range (step S29). Then, the process returns to step S21. In other words, when a certain period of time has passed since it is considered that the vehicle ahead is not moving left or right, the expanded dimming range is changed to the light irradiation range and the irradiation light is formed.

The timer monitoring operation by the timer (not shown) will be described in detail with reference to FIG. 11. If the timer is currently timing by going through step S27 (step S31), it continues counting down (step S32). Then, when a certain period of time has passed and the count has expired (step S33; YES), it stops counting (step S34). On the other hand, if the timer is not currently timing (step S31; NO) or the count has not expired (step S33; NO), it returns to step S31. As a result, if a certain period of time has passed without going through step S25, it will proceed from step S28 to step S29. On the other hand, if the timer has gone through step S25, the counting will stop and the countdown will not proceed until the timer goes through step S25 again.

Figures 12(A) and 12(B) are diagrams for explaining an example of light distribution control by a vehicle lighting system. Here, an example of light distribution control is shown in which a leading vehicle 102 is located relatively far from the vehicle itself and the leading vehicle 102 moves to the right due to a lane change or the like. Figure 12(A) corresponds to the state before the leading vehicle 102 moves, and Figure 12(B) corresponds to the state after the leading vehicle 102 moves (or during movement). Before the movement, a dimming range 250 is provided according to the position of the leading vehicle 102, and light irradiation ranges 251 and 252 are provided on both sides of the dimming range 250. After the movement, the ranges of the dimming range 250 and the light irradiation ranges 251 and 252 are changed, and an extended dimming range 253 is provided to the right of the dimming range 250.

When the position of the forward vehicle 102 is far from the vehicle itself, the angular velocity during movement is relatively small, so the width (gradation width) of the expanded dimming range 253 is set to be relatively small. In the illustrated example, the expanded dimming range 253 is formed by multiple segments 301 in region R1. Although not illustrated, it is assumed that a brightness gradation is expressed. In addition, since the angular velocity is small, the gradual change time is set long, and the brightness also changes gradually. However, in this example, each segment 301 belongs to region R1, so the gradual change time is corrected to be shorter accordingly. This type of light distribution control mainly reduces the sense of discomfort felt by the driver of the vehicle itself.

For example, if the gradation width is set to 1.0 deg, the position where the extended dimming range 253 is provided is included in region R1, and the width of each segment 301 is 0.3 deg, then the illumination light of the extended dimming range 253 is formed using four segments 301. Then, for example, the brightness of each segment 301 is set to 18%, 37%, 56%, and 75% of the maximum value (e.g., brightness in the light illumination range) in order of proximity to the dimming range 250. This achieves a gradation light distribution that is darker the closer to the dimming range 250 and brighter the further away.

Figures 13(A) and 13(B) are diagrams for explaining an example of light distribution control by a vehicle lighting system. Here, an example of light distribution control is shown in which a leading vehicle 102 is relatively close to the vehicle in question, and the leading vehicle 102 moves to the right due to a lane change or the like. Figure 13(A) corresponds to the state before the leading vehicle 102 moves, and Figure 13(B) corresponds to the state after the leading vehicle 102 moves (or during movement). Before the movement, a dimming range 250 is provided according to the position of the leading vehicle 102, and light irradiation ranges 251 and 252 are provided on both sides of the dimming range 250. After the movement, the ranges of the dimming range 250 and the light irradiation ranges 251 and 252 are changed, and an extended dimming range 253 is provided to the right of the dimming range 250.

When the position of the vehicle 102 ahead is close to the vehicle itself, the angular velocity during movement is relatively large, so the width (gradation width) of the extended dimming range 253 is set to be relatively large. In the illustrated example, the extended dimming range 253 is formed by multiple segments 302, 303 in regions R2 and R3. Although not shown in the figure, it is assumed that a brightness gradation is expressed. In addition, since the angular velocity is large, the gradual change time is set to be short, and the brightness changes quickly. Furthermore, the gradual change time is corrected to be long for each segment 303 in region R3. This reduces the sense of discomfort felt by the driver of the vehicle itself and also reduces the possibility of causing glare to the vehicle 102 ahead.

Figures 14(A) and 14(B) are diagrams for explaining an example of light distribution control by a vehicle lighting system. Here, an example of light distribution control is shown when the vehicle in front 102, which is an oncoming vehicle, passes the vehicle itself. Figure 14(A) corresponds to the state before the vehicle in front 102 moves, and Figure 14(B) corresponds to the state after the vehicle in front 102 moves (or while it is moving). Before the movement, a dimming range 250 is provided according to the position of the vehicle in front 102, and light irradiation ranges 251 and 252 are provided on both sides of the dimming range. After the movement, the ranges of the dimming range 250 and the light irradiation ranges 251 and 252 are changed, and an extended dimming range 253 is provided to the right of the dimming range 250.

When the position of the vehicle 102 ahead is close to the vehicle itself, the angular velocity during movement is relatively large, so the width (gradation width) of the extended dimming range 253 is set relatively large. In the illustrated example, the extended dimming range 253 is formed by multiple segments 303, 304 in region R3. Although not illustrated, it is assumed that a brightness gradation is expressed. In addition, since the angular velocity is large, the gradual change time is set short, and the brightness also changes quickly. However, the gradual change time is corrected to be long for each segment 303, 304 in region R3. This reduces the sense of discomfort felt by the driver of the vehicle itself and also reduces the possibility of causing glare to the vehicle 102 ahead.

In this way, this embodiment makes it possible to reduce the possibility of causing glare to preceding or oncoming vehicles.

Note that the present disclosure is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the gist of the present disclosure. For example, in the above-described embodiment, angular velocity is used as the moving speed of the forward vehicle in the left-right direction, but the moving distance per unit time in the left-right direction may be used.

10: Imaging device, 11: Controller, 12L, 12R: Headlight, 20: Vehicle position acquisition unit, 21: Angular velocity calculation unit, 22: Light distribution pattern setting unit, 23: Control signal generation unit, 30: Low beam unit, 31: ADB unit, 100: Vehicle, 102: Vehicle ahead, 250: Dimming range, 251, 252: Light irradiation range, 253: Extended dimming range, 301, 302, 303, 304: Segments

Claims (6)

A vehicle lamp;
A control device for causing the vehicle lamp to form an illumination light having a light distribution pattern according to the position of a vehicle ahead ;
A vehicle lighting system comprising :
the control device sets a dimming range and a light irradiation range in response to the position of the vehicle ahead, and sets an extended dimming range to the left or right of the dimming range in response to the moving direction of the vehicle ahead in the vehicle width direction, and generates a control signal to cause the vehicle lamp to form irradiation light of a light distribution pattern including the dimming range, the light irradiation range, and the extended dimming range,
the brightness of the irradiated light corresponding to each of the light irradiation range, the dimming range, and the expanded dimming range is set by increasing or decreasing the brightness of the irradiated light for each of a plurality of segments divided in the vehicle width direction,
a width of the expanded dimming range is set to be relatively large when a moving speed of the forward vehicle in a vehicle width direction is relatively large, and is set to be relatively small when the moving speed is relatively small;
The brightness of the extended dimming range is set so that a portion close to the dimming range is relatively dark and a portion far from the dimming range is relatively bright ,
a gradual change time for the brightness of the segment corresponding to the expanded dimming range, which is a time required for changing the brightness from a state before the change to a set brightness, is set to be relatively shorter as the moving speed is faster and to be relatively longer as the moving speed is slower;
The plurality of segments include at least one or more first segments having a relatively small width, one or more second segments having a larger width than the first segments, and one or more third segments having a larger width than the second segments;
The gradual-change time corresponding to the first segment is corrected to be shorter than the gradual-change time corresponding to the second segment, and the gradual-change time corresponding to the third segment is corrected to be longer than the gradual-change time corresponding to the second segment.
Vehicle lighting system . A vehicle lamp;
A control device for causing the vehicle lamp to form an illumination light having a light distribution pattern according to the position of a vehicle ahead ;
A vehicle lighting system comprising :
The control device includes:
a light distribution pattern setting unit that sets a dimming range and a light irradiation range in accordance with the position of the forward vehicle, and sets an extended dimming range to the left or right of the dimming range in accordance with the moving direction of the forward vehicle in a vehicle width direction;
a control signal generating unit that generates a control signal for causing the vehicle lamp to form irradiation light of a light distribution pattern including the dimming range, the light irradiation range, and the expanded dimming range;
Including,
the brightness of the irradiated light corresponding to each of the light irradiation range, the dimming range, and the expanded dimming range is set by increasing or decreasing the brightness of the irradiated light for each of a plurality of segments divided in the vehicle width direction,
a width of the expanded dimming range is set to be relatively large when a moving speed of the forward vehicle in a vehicle width direction is relatively large, and is set to be relatively small when the moving speed is relatively small;
The brightness of the extended dimming range is set so that a portion close to the dimming range is relatively dark and a portion far from the dimming range is relatively bright,
a gradual change time for the brightness of the segment corresponding to the expanded dimming range, which is a time required for changing the brightness from a state before the change to a set brightness, is set to be relatively shorter as the moving speed is faster and to be relatively longer as the moving speed is slower;
The plurality of segments include at least one or more first segments having a relatively small width, one or more second segments having a larger width than the first segments, and one or more third segments having a larger width than the second segments;
The gradual-change time corresponding to the first segment is corrected to be shorter than the gradual-change time corresponding to the second segment, and the gradual-change time corresponding to the third segment is corrected to be longer than the gradual-change time corresponding to the second segment.
Vehicle lighting system . The vehicle lamp includes an ADB unit that receives the control signal from the control device and operates,
The ADB unit is configured to include any one of a unit including a light source, a liquid crystal element, a polarizing plate, and a projection lens, a unit including a plurality of LEDs that can be selectively turned on/off, and a unit including a laser element and a movable reflector that scans the light from the laser element.
3. A vehicle lighting system according to claim 1 or 2. The expanded dimming range is changed to the light irradiation range when the moving speed becomes equal to or less than a reference value.
The vehicle lighting system according to any one of claims 1 to 3 . The moving speed is a change in the position of the forward vehicle expressed as an angular velocity.
The vehicle lighting system according to any one of claims 1 to 4 . The moving speed is a moving distance of the forward vehicle per unit time in the left-right direction.
The vehicle lighting system according to any one of claims 1 to 4 .

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