Lamp system, light distribution control device, and computer program

Abstract

A lamp system 1 comprises: an imaging device 4; a variable light distribution lamp 2; a first bracket 8 which supports the imaging device 4; a second bracket 10 which supports the variable light distribution lamp 2 such that an emission direction 2x thereof can be changed, and which is independently displaceable relative to the first bracket 8; an emission direction sensor 12; and a light distribution control device 6 which detects a target object using an image IMG, defines the position of a shaded portion corresponding to the target object on the basis of a mutual correspondence relationship between an imaging direction 4x and the emission direction 2x, and controls the variable light distribution lamp 2 to form a light distribution pattern PTN having the shaded portion. If the emission direction 2x changes, the light distribution control device 6 defines the shaded portion 44 at a position shifted from the position of the shaded portion 44 determined on the basis of the correspondence relationship before the change, the position of the shaded portion 44 being shifted by an amount corresponding to the amount of change in the emission direction 2x.

Description

Lighting fixture system, light distribution control device and computer program

[0001] The present invention relates to a lighting system, a light distribution control device, and a computer program.

[0002] Adaptive Driving Beam (ADB) control is known, which dynamically and adaptively controls a light distribution pattern based on the conditions around a vehicle (see, for example, Patent Document 1). ADB control uses a camera to detect the presence or absence of a vehicle ahead that should avoid high-intensity light irradiation, and blocks the area corresponding to the vehicle ahead. By blocking the area corresponding to the vehicle ahead and irradiating other areas with light, it is possible to reduce glare for the driver of the vehicle ahead while improving visibility for the driver of the vehicle ahead.

[0003] International Publication No. 2019 / 176418

[0004] In a lighting system mounted on a vehicle, aiming adjustment is generally performed to adjust the illumination direction of the headlamp. In a configuration in which the imaging direction of the camera and the illumination direction of the lamp can be displaced relative to each other, such as when the camera and the headlamp are mounted on different brackets, the correspondence between the imaging direction and the illumination direction may change from what was previously understood. In this case, a misalignment may occur between the target detected by the camera and the shading portion formed for this target.

[0005] The present invention has been made in view of the above circumstances, and one of its objects is to provide a technique for forming a light-shielding portion with high precision.

[0006] 1. In order to solve the above-mentioned problems, one aspect of the present invention is a lighting system. The lighting system includes an imaging device that captures an image of the area ahead of the vehicle, a variable light distribution lamp that can form a light distribution pattern having a shading portion, a first bracket that supports the imaging device, a second bracket that supports the variable light distribution lamp so that the illumination direction can be changed and that is movable independently of the first bracket, an illumination direction sensor that detects the amount of change in the illumination direction, and a light distribution control device that detects a target object using an image captured by the imaging device, determines the position of the shading portion corresponding to the target object based on the correspondence between the imaging direction and the illumination direction of the imaging device, and controls the variable light distribution lamp to form a light distribution pattern having the shading portion. When the illumination direction is changed, the light distribution control device determines the position of the shading portion at a position that is shifted by an amount corresponding to the change from the position of the shading portion that would be determined based on the correspondence before the change.

[0007] Another aspect of the present invention is a light distribution control device that detects a target using an image based on an imaging device that captures an image of the area ahead of a vehicle, determines the position of a shading portion corresponding to the target based on the correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, and controls the variable light distribution lamp to form a light distribution pattern having the shading portion. This light distribution control device acquires a detection result from an irradiation direction sensor that detects the amount of change in the irradiation direction, and when the irradiation direction is changed, determines the shading portion at a position that is shifted by an amount corresponding to the amount of change from the position of the shading portion that would have been determined based on the correspondence before the change.

[0008] Another aspect of the present invention is a light distribution control device that detects a target using an image based on an imaging device that captures an image of the area ahead of a vehicle, determines the position of a shading portion corresponding to the target based on a correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, and controls the variable light distribution lamp to form a light distribution pattern having the shading portion. This light distribution control device determines, for the same target at the same position relative to the vehicle, when the imaging direction and the irradiation direction have a first correspondence, with the imaging direction with respect to the target fixed, and determines the shading portion at a second position in the light distribution pattern that is shifted from the first position, when the imaging direction and the irradiation direction have a second correspondence that is different from the first correspondence.

[0009] Another aspect of the present invention is a computer program executed by a light distribution control device that detects a target using an image captured by an imaging device that captures an image of the area ahead of the vehicle, determines the position of a shading portion corresponding to the target based on a correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, and controls the variable light distribution lamp to form a light distribution pattern having the shading portion. This computer program acquires a detection result from an irradiation direction sensor that detects an amount of change in the irradiation direction, and, when the irradiation direction is changed, causes the light distribution control device to perform a function of determining the shading portion at a position that is shifted by an amount corresponding to the amount of change from the position of the shading portion that would be determined based on the correspondence before the change.

[0010] 2. To solve the above problem, one aspect of the present invention is a lighting system. The lighting system includes an imaging device that captures an image ahead of the vehicle, a variable light distribution lamp that can form a light distribution pattern having a shading portion, a first bracket that supports the imaging device, a second bracket that supports the variable light distribution lamp so that the illumination direction can be changed and that is movable independently of the first bracket, an illumination direction sensor that detects an amount of change in the illumination direction, and a light distribution control device that sets a processing area for an image based on the imaging direction and illumination direction of the imaging device, performs target detection processing on the processing area to detect targets, and controls the variable light distribution lamp to form a light distribution pattern having a shading portion that corresponds to the targets. When the illumination direction is changed, the light distribution control device sets the processing area at a position that is shifted by an amount corresponding to the amount of change from the position of the processing area that would be determined based on the correspondence before the change.

[0011] Another aspect of the present invention is a light distribution control device that sets a processing area for an image based on an imaging device that captures an image ahead of a vehicle based on the mutual correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, performs target detection processing on the processing area to detect the target, and controls the variable light distribution lamp to form a light distribution pattern having a shading portion corresponding to the target. This light distribution control device acquires a detection result from an irradiation direction sensor that detects the amount of change in the irradiation direction, and when the irradiation direction is changed, sets the processing area at a position shifted by an amount corresponding to the amount of change from the position of the processing area that would be determined based on the correspondence before the change.

[0012] Another aspect of the present invention is a light distribution control device that sets a processing area for an image based on an imaging device that captures an image ahead of a vehicle based on a correspondence relationship between the imaging direction of the imaging device and the illumination direction of a variable light distribution lamp, performs target detection processing on the processing area to detect the target, and controls the variable light distribution lamp to form a light distribution pattern having a shading portion corresponding to the target. This light distribution control device determines, for the same target at the same position relative to the vehicle, a shading portion in the light distribution pattern when the imaging direction and the illumination direction have a first correspondence relationship, with the imaging direction with respect to the target fixed, and does not determine a shading portion in the light distribution pattern when the imaging direction and the illumination direction have a predetermined second correspondence relationship different from the first correspondence relationship.

[0013] Another aspect of the present invention is a computer program executed by a light distribution control device that sets a processing area for an image based on an imaging device that captures an image of the area in front of the vehicle based on a correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, performs target detection processing on the processing area to detect the target, and controls the variable light distribution lamp to form a light distribution pattern having a shading portion corresponding to the target. This computer program acquires a detection result from an irradiation direction sensor that detects an amount of change in the irradiation direction, and, when the irradiation direction is changed, causes the light distribution control device to perform a function of setting the processing area at a position shifted by an amount corresponding to the amount of change from the position of the processing area that would be determined based on the correspondence before the change.

[0014] Any combination of the above components and conversion of the present invention into a method, device, system, etc. are also valid aspects of the present invention.

[0015] According to the present invention, the light-shielding portion can be formed with high precision.

[0016] 1 is a block diagram of a lighting system according to Embodiments 1 and 3. FIGS. 2(A), 2(B), 2(C), and 2(D) are diagrams illustrating the basic operation of light distribution control. FIGS. 3(A), 3(B), 3(C), and 3(D) are diagrams illustrating a case where the basic operation is performed in a situation where the correspondence between the illumination direction and the imaging direction has changed since initial aiming. FIGS. 3(A), 3(B), 3(C), and 3(D) are schematic diagrams illustrating a method for correcting the correspondence. FIGS. 5(A), 5(B), 5(C), and 5(D) are diagrams illustrating light distribution control involving a process for correcting the correspondence. A flowchart illustrating an example of control performed by a light distribution control device. FIGS. 8(A), 8(B), 8(C), and 8(D) are diagrams illustrating a case where the basic operation is performed in a situation where the correspondence between the illumination direction and the imaging direction has changed since initial aiming in Embodiment 3. 9A, 9B, 9C, and 9D are diagrams illustrating light distribution control accompanied by a process for correcting the correspondence relationship in the third embodiment.

[0017] The present invention will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in the drawings are designated by the same reference numerals, and redundant descriptions are omitted where appropriate. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted in the drawings.

[0018] (Embodiment 1) Fig. 1 is a block diagram of a lighting system 1 according to embodiment 1. In Fig. 1, the components of the lighting system 1 are depicted as functional blocks. These functional blocks are realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

[0019] The lighting system 1 includes a variable light distribution lamp 2, an imaging device 4, a light distribution control device 6, a first bracket 8, a second bracket 10, and an irradiation direction sensor 12. These are mounted on a vehicle. In this embodiment, the vehicle on which the lighting system 1 is mounted is, for example, a saddle-type vehicle such as a motorcycle.

[0020] The above-described variable light distribution lamp 2, image capture device 4, light distribution control device 6, first bracket 8, second bracket 10, and irradiation direction sensor 12 may all be housed in the same housing, or some of the mechanisms may be provided outside the housing. For example, the mechanisms may be housed in a lamp chamber. The lamp chamber is defined by a lamp body having an opening on the front side of the vehicle and a translucent cover attached to cover the opening of the lamp body.

[0021] The imaging device 4, light distribution control device 6, first bracket 8, and irradiation direction sensor 12 may be disposed outside the lamp chamber, for example, on the vehicle side. In this case, the imaging device 4 may be an on-board camera. If the imaging device 4 is an on-board camera, the vehicle body BD may correspond to the first bracket 8. Furthermore, the light distribution control device 6 may be configured, for example, in whole or in part, by a vehicle ECU.

[0022] The variable light distribution lamp 2 is capable of irradiating a visible light beam L1 with a variable intensity distribution toward a region ahead of the vehicle. The variable light distribution lamp 2 is capable of individually changing the illuminance of light irradiated onto multiple individual regions R arranged in the forward region. In other words, the variable light distribution lamp 2 is capable of irradiating the space ahead of the vehicle with light of different illuminances depending on the location (individual region R). The multiple individual regions R may be arranged, for example, in a line in the vehicle width direction or in a matrix. The variable light distribution lamp 2 receives information instructing a light distribution pattern PTN from the light distribution control device 6 and emits a visible light beam L1 having an intensity distribution corresponding to the light distribution pattern PTN. This forms the light distribution pattern PTN ahead of the vehicle. The light distribution pattern PTN can be understood as the two-dimensional illuminance distribution of an irradiation pattern 902 formed by the variable light distribution lamp 2 on a virtual vertical screen 900 ahead of the vehicle.

[0023] The variable light distribution lamp 2 may have any configuration, including, for example, a plurality of light sources arranged in a horizontal row or a matrix, and a lighting circuit that independently drives and lights each light source. Preferred examples of light sources include semiconductor light sources such as LEDs (light-emitting diodes), LDs (laser diodes), and organic or inorganic ELs (electroluminescence). Each individual region R is associated with a light source, and each light source individually irradiates each individual region R with light. The resolution of the variable light distribution lamp 2, or in other words, the light distribution resolution, is, for example, approximately 4 to 20 pixels when the light sources are arranged in a horizontal row, and approximately 1,000 to 2,000,000 pixels when the light sources are arranged in a matrix. The resolution of the variable light distribution lamp 2 refers to the number of unit regions whose illuminance can be independently changed in the light distribution pattern PTN.

[0024] In order to form an illuminance distribution according to the light distribution pattern PTN, the variable light distribution lamp 2 may include a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device, or a scanning optical pattern forming device that scans the area ahead of the vehicle with light from a light source. Also, a shade plate may be used to partially block light irradiation to the area ahead.

[0025] The imaging device 4 is, for example, a camera that is sensitive to the visible light region and repeatedly captures images of the area ahead of the vehicle. The imaging device 4 captures reflected light L2 of the visible light beam L1 by objects ahead of the vehicle. The imaging device 4 also captures light emitted by vehicles ahead, including leading and oncoming vehicles, as well as light emitted by self-luminous objects such as streetlights and electronic billboards. The image IMG generated by the imaging device 4 is sent to the light distribution control device 6.

[0026] The image IMG that the light distribution control device 6 acquires from the imaging device 4 may be RAW image data, or may be image data that has been subjected to predetermined image processing by the imaging device 4. In addition, the case in which the light distribution control device 6 receives image data in which RAW image data generated by the imaging device 4 has been subjected to image processing by a processing device other than the imaging device 4 also corresponds to acquisition of the image IMG from the imaging device 4. In the following description, "image IMG based on the imaging device 4" means that it may be either RAW image data or data that has been subjected to image processing. In addition, both types of image data may sometimes be expressed as "image IMG" without making a distinction between them.

[0027] The light distribution control device 6 detects a target using the image IMG based on the imaging device 4, and controls the variable light distribution lamp 2 to form a light distribution pattern PTN having a light-blocking portion corresponding to the detected target. In other words, the light distribution control device 6 performs ADB control, which dynamically and adaptively controls the light distribution of the variable light distribution lamp 2 according to targets present in the forward area. The light distribution control device 6 of this embodiment detects a vehicle ahead as the target. Note that the light distribution control device 6 may also detect targets other than a vehicle ahead. In this embodiment, the expression "corresponding to the target" of the light-blocking portion means that the light-blocking portion overlaps with the target when the light distribution pattern PTN is projected forward. The light distribution control device 6 sends information indicative of the light distribution pattern PTN to the variable light distribution lamp 2.

[0028] The light distribution control device 6 can be configured with a digital processor, for example, a combination of a microcomputer including a CPU and a software program. The light distribution control device 6 may also be configured with an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific IC).

[0029] The light distribution control device 6 includes a control unit 16 configured with a CPU or the like, and a storage medium 18 configured with memory and storage. The control unit 16 includes, by way of example, an area setting unit 20, a detection unit 22, a pattern determination unit 24, a lamp control unit 26, and a correction unit 28. The storage medium 18 stores computer programs executed by the light distribution control device 6 (more specifically, the control unit 16) and information on correspondence relationships, which will be described later. Each unit included in the control unit 16 operates when an integrated circuit that constitutes the unit executes a program stored in the storage medium 18. The operation of each unit will be described later.

[0030] The control unit 16 can also receive signals transmitted from an ignition switch 30, a vehicle speed sensor 32, a shift sensor 34, an accelerator sensor 36, and a stand sensor 38 mounted on the vehicle. The ignition switch 30 transmits a signal indicating whether the ignition is on or off to the control unit 16. The vehicle speed sensor 32 transmits a signal indicating the vehicle speed to the control unit 16. The shift sensor 34 transmits a signal indicating the shift position to the control unit 16. The accelerator sensor 36 transmits a signal indicating the amount of accelerator operation by the driver to the control unit 16. The stand sensor 38 transmits a signal to the control unit 16 indicating whether a stand ST supporting the vehicle body BD is in the upright position or the retracted position. The lighting system 1 may be mounted on a vehicle other than a saddle-type vehicle, such as a four-wheeled vehicle. In this case, the vehicle does not have a stand ST and a stand sensor 38.

[0031] The first bracket 8 supports the imaging device 4. The first bracket 8 of this embodiment supports the imaging device 4 so that the imaging direction 4x is immovable. The first bracket 8 has a known structure. The "imaging direction 4x" of the imaging device 4 can be rephrased as the "angle of the imaging axis" or "direction" of the imaging device 4.

[0032] The second bracket 10 supports the variable light distribution lamp 2 so that the irradiation direction 2x can be changed. The second bracket 10 has a known structure. As an example, the second bracket 10 has a second aiming screw 42. By rotating the second aiming screw 42, the position of the second bracket 10 can be changed up, down, left, or right, and therefore the irradiation direction 2x of the variable light distribution lamp 2 can be tilted up, down, left, or right. The "irradiation direction 2x" of the variable light distribution lamp 2 can be rephrased as the "angle of the optical axis" or "orientation" of the variable light distribution lamp 2.

[0033] The second bracket 10 can be displaced independently of the first bracket 8. Therefore, the correspondence between the imaging direction 4x and the irradiation direction 2x can change from the state set by the initial aiming performed at the vehicle manufacturer's manufacturing plant, a dealer's repair shop, or the like, due to displacement of the second bracket 10 that can occur during use of the vehicle.

[0034] The irradiation direction sensor 12 can detect the amount of change (amount of change in angle) in the irradiation direction 2x of the variable light distribution lamp 2. The irradiation direction sensor 12 includes, for example, a known potentiometer, and can detect the amount of change in the irradiation direction 2x from the amount of rotation (rotation angle) of the second aiming screw 42. The irradiation direction sensor 12 sends a signal indicating the detection result to the control unit 16. Note that the irradiation direction sensor 12 may also send the amount of rotation of the second aiming screw 42 itself (a voltage corresponding to the amount of rotation) to the control unit 16 as information indicating the amount of change in the irradiation direction 2x.

[0035] The structure and method for changing the irradiation direction 2x are not limited to those using the second aiming screw 42, and other known structures and methods may be employed. Furthermore, the method for detecting the amount of change by the irradiation direction sensor 12 may be appropriately selected depending on the structure and method for changing the irradiation direction 2x.

[0036] Next, the operation of the light distribution control device 6 will be described. Figures 2(A), 2(B), 2(C), and 2(D) are diagrams illustrating the basic operation of light distribution control. Figure 2(A) shows the imaging area 4a of the imaging device 4 and a light distribution pattern PTN formed in front of the vehicle. Here, a high beam light distribution pattern is shown as an example of the light distribution pattern PTN. Also, for convenience, Figure 2(A) illustrates a processing area ROI set in the image IMG (in other words, the imaging area 4a). The following description will be given using an oncoming vehicle 201 as an example of a target.

[0037] When an oncoming vehicle 201 is present ahead of the vehicle, an image IMG including the oncoming vehicle 201 is generated by the imaging device 4 and sent to the light distribution control device 6. The image IMG sent to the light distribution control device 6 is acquired by the region setting unit 20. The region setting unit 20 sets a processing region ROI for the image IMG. The position where the processing region ROI should be set and the shape of the processing region ROI can be determined in advance based on experiments or simulations by a designer. For example, the processing region ROI is set in a range on the image IMG that overlaps with the irradiation range of the light distribution pattern PTN. Information on the processing region ROI includes position coordinates in the image IMG and is stored in advance in the storage medium 18. The image IMG in which the processing region ROI has been set is sent to the detection unit 22.

[0038] The detection unit 22 extracts a processing region ROI from the image IMG, as shown in FIG. 2B. Then, it performs known image processing, such as binarization, on the processing region ROI. As a result, a light spot image IMGa is generated, as shown in FIG. 2C, in which two light spots 202 corresponding to the lamps of the oncoming vehicle 201 are extracted. The lamps of the oncoming vehicle 201 are headlamps, etc. Note that when the detection target is a preceding vehicle, light spots 202 corresponding to the rear lamps, etc. of the preceding vehicle are included in the light spot image IMGa. The rear lamps include stop lamps and tail lamps.

[0039] The detection unit 22 determines the presence or absence of a target using the light spot image IMGa. Performing target detection processing on the light spot image IMGa corresponds to performing target detection processing on the image IMG or the processing region ROI. When a light spot 202 is included in the light spot image IMGa, the detection unit 22 detects a target based on the light spot 202. For example, the detection unit 22 determines that the light spot 202 present in the processing region ROI originates from a target, in other words, that a target exists at the position where the light spot 202 is present.

[0040] The detection unit 22 sends the detection result to the pattern determination unit 24. The target detection method implemented by the detection unit 22 is not particularly limited. For example, the generation of the light spot image IMGa may be omitted, and targets may be detected from the processing region ROI using a known method including algorithm recognition, deep learning, etc. The type of target (forward vehicle, oncoming vehicle 201, preceding vehicle, sign, etc.) may or may not be identified. The detection unit 22 can identify the type of target by the above-mentioned algorithm recognition or deep learning, or based on known judgment indices such as the position of the light spots 202 or whether the light spots 202 are paired (pairing).

[0041] When a target object is detected, the pattern determination unit 24 sets a shading portion 44 in an area corresponding to the target object in the base light distribution pattern, as shown in FIG. 2(D). This determines the light distribution pattern PTN to be formed. The shading portion 44 is a portion in the light distribution pattern PTN where the brightness (illuminance) is 0, or a portion where the brightness is greater than 0, that is, where the brightness is lower than before shading. When a target object is not detected, the pattern determination unit 24 determines a light distribution pattern PTN that does not have a shading portion 44.

[0042] The base light distribution pattern is selected according to a light distribution mode that is determined based on, for example, a driver's instruction via operation of a light switch (not shown), the driving state of the vehicle, the environment around the vehicle, etc. For example, the light distribution mode includes a high beam mode that forms a light distribution pattern for high beams, a low beam mode that forms a light distribution pattern for low beams, a town mode that forms a light distribution pattern suitable for driving in urban areas, etc. Figure 2(D) shows an example of a light distribution pattern for high beams.

[0043] The position of the light-blocking portion 44 is determined based on the correspondence between the imaging direction 4x and the irradiation direction 2x. Information on this correspondence links position coordinates in the image IMG with position coordinates in the light distribution pattern PTN, and is created, for example, during initial aiming and stored in the storage medium 18. Based on this correspondence, the position of the light-blocking portion 44 in the light distribution pattern PTN can be determined from the position of the target in the light spot image IMGa. As an example, the pattern determination unit 24 determines a light-blocking portion 44 of a predetermined shape in the light distribution pattern PTN. The pattern determination unit 24 may also perform a known expansion / contraction process on the light spot image IMGa to deform the shape of the light spot 202 and use the deformed shape of the light spot 202 as the shape of the light-blocking portion 44. The pattern determination unit 24 sends information on the determined light distribution pattern PTN to the lamp control unit 26.

[0044] The lamp control unit 26 instructs the variable light distribution lamp 2 to form a light distribution pattern PTN. The lamp control unit 26 is configured, for example, with a known LED driver module (LDM). If the dimming method of the light source of the variable light distribution lamp 2 is analog dimming, the lamp control unit 26 adjusts the DC level of the drive current flowing through the light source. If the dimming method of the light source is PWM (Pulse Width Modulation) dimming, the lamp control unit 26 adjusts the average level of the drive current by switching the current flowing through the light source and adjusting the ratio of the on period. If the variable light distribution lamp 2 has a DMD, the lamp control unit 26 controls the on / off switching of each mirror element constituting the DMD. If the variable light distribution lamp 2 has a liquid crystal device, the lamp control unit 26 controls the light transmittance of the liquid crystal device. As a result, the light distribution pattern PTN is formed in front of the vehicle.

[0045] Next, the position correction of the light-shielding portion 44 when the correspondence between the irradiation direction 2x and the imaging direction 4x has changed since the initial aiming will be described. Figures 3(A), 3(B), 3(C), and 3(D) are diagrams illustrating a case where the basic operation is performed in a situation where the correspondence between the irradiation direction 2x and the imaging direction 4x has changed since the initial aiming.

[0046] As described above, the light distribution control device 6 determines the shading portion 44 corresponding to the target in the light distribution pattern PTN based on the correspondence between the imaging direction 4x and the irradiation direction 2x. In such control, if the correspondence changes from that obtained during initial aiming, a situation may arise in which the shading portion 44 deviates from the target when the light distribution pattern PTN is irradiated.

[0047] For example, an auto-leveling function has been put into practical use for adjusting the irradiation direction 2x. In this case, if the vehicle posture changes due to loading of luggage or the like, the posture of the second bracket 10 is automatically changed by the auto-leveling function before the vehicle starts traveling. This adjusts the irradiation direction 2x to an angle that matches the vehicle posture. The irradiation direction 2x may also be changed manually.

[0048] If the variable light distribution lamp 2 and the imaging device 4 are mounted on the same bracket, the irradiation direction 2x can be changed while maintaining the correspondence between the irradiation direction 2x and the imaging direction 4x at the time of initial aiming. However, if the variable light distribution lamp 2 and the imaging device 4 are mounted on the same bracket, the bracket becomes large, and the location where the bracket can be installed may be limited. In this case, the degree of freedom in arranging the variable light distribution lamp 2 and the imaging device 4 is reduced. For this reason, it is desirable to mount the variable light distribution lamp 2 and the imaging device 4 on separate brackets, as in this embodiment.

[0049] When the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets, the imaging direction 4x is often fixed as in this embodiment. One reason for this is that the imaging range of the imaging device 4 is generally wider than the irradiation range of the variable light distribution lamp 2, and so even if the imaging direction 4x remains fixed, it is possible to capture the entire light distribution pattern PTN after the irradiation direction 2x has shifted. Therefore, when the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets, the correspondence between the irradiation direction 2x and the imaging direction 4x may change from the time of initial aiming.

[0050] When the irradiation direction 2x is changed, the relative positions of the imaging area 4a and the light distribution pattern PTN change, as shown in Fig. 3(A). In this state, a processing area ROI is set in the image IMG. Next, the processing area ROI is extracted as shown in Fig. 3(B), and a light spot image IMGa is generated as shown in Fig. 3(C). Then, as shown in Fig. 3(D), a light-shielding portion 44 is set in the area of ​​the light distribution pattern PTN corresponding to the target.

[0051] In the basic operation, the position coordinates of the light spot 202 in the light spot image IMGa are converted into the position coordinates of the light-blocking portion 44 in the light distribution pattern PTN based on the correspondence relationship created during initial aiming. In this case, the light-blocking portion 44 determined in the light distribution pattern PTN after the irradiation direction 2x is changed is shifted in the direction of the change in the irradiation direction 2x from the position where it should have been set by an amount corresponding to the change in the irradiation direction 2x. As a result, when the determined light distribution pattern PTN is projected ahead of the vehicle, the light-blocking portion 44 is shifted from the target.

[0052] Therefore, when the irradiation direction 2x is changed, the light distribution control device 6 of this embodiment determines the position of the shading section 44 to be shifted by an amount corresponding to the amount of change in the irradiation direction 2x from the position of the shading section 44 that would be determined based on the correspondence relationship before the change in the irradiation direction 2x.

[0053] As an example, the correction unit 28 of the light distribution control device 6 corrects the correspondence information based on the amount of change in the irradiation direction 2x at a predetermined timing, and stores the corrected information in the storage medium 18 as new correspondence information.

[0054] The predetermined timing may be at least one of when the ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range (for example, the drive range or first gear), and when the accelerator is switched from an off state to an on state. Furthermore, the lighting system 1 of this embodiment is mounted on a saddle-ride type vehicle. Therefore, the predetermined timing may also be when the stand ST is switched from the upright position to the retracted position.

[0055] The correction unit 28 performs the correction process of the correspondence relationship by receiving trigger signals indicating that a predetermined timing has occurred from the ignition switch 30, the vehicle speed sensor 32, the shift sensor 34, the accelerator sensor 36, and the stand sensor 38. The correction unit 28 may perform the correction process every time it obtains a detection result from the irradiation direction sensor 12.

[0056] The process of correcting the correspondence relationship based on the amount of change in the irradiation direction 2x can be performed as follows. Fig. 4 is a schematic diagram for explaining the method of correcting the correspondence relationship. As shown in Fig. 4, for example, when the variable light distribution lamp 2 and the image capture device 4 are mutually offset by x in the X-axis direction, ｄ shifted by y in the Y-axis direction ｄ The angle between the irradiation direction 2x (which coincides with the X axis) of the variable light distribution lamp 2 and the imaging direction 4x of the imaging device 4 is θ ｄ The deviation amount x between the installation positions of the variable light distribution lamp 2 and the image capture device 4 is ｄ , y ｄ is measured in advance and stored in the storage medium 18.

[0057] Assume that a target p exists on a virtual vertical screen 900 that is a distance x away from the variable light distribution lamp 2 in the X-axis direction. The target p is located at a distance x away from the variable light distribution lamp 2 in the X-axis direction and a distance y away from the irradiation direction 2x of the variable light distribution lamp 2. The angle of the target p when viewed from the variable light distribution lamp 2 is θ ｅ The angle of the target p when viewed from the imaging device 4 is θ ｃ Angle θ ｅ and angle θ ｃ The difference between the above is the parallax shift θ between the variable light distribution lamp 2 and the image capture device 4. Ｏ is.

[0058] The variable light distribution lamp 2 and the image capture device 4 are mutually x ｄ and y ｄ The irradiation direction 2x and the imaging direction 4x are offset by an angle θ ｄ In this case, the parallax deviation θ between the variable light distribution lamp 2 and the image capturing device 4 is Ｏ can be expressed by the following equation (1): Ｏ=atan(y / x)-[atan{(y-y ｄ ) / (x-x ｄ )-θ ｄ ]

[0059] If the X-axis direction is the front-rear direction of the variable light distribution lamp 2 and the imaging device 4, and the Y-axis direction is the up-down direction of the variable light distribution lamp 2 and the imaging device 4, the parallax shift θ in the up-down direction between the variable light distribution lamp 2 and the imaging device 4 is Ｏ Furthermore, if the X-axis direction is the front-rear direction of the variable light distribution lamp 2 and the imaging device 4, and the Y-axis direction is the left-right direction of the variable light distribution lamp 2 and the imaging device 4, then the parallax shift θ Ｏ can be calculated.

[0060] The correspondence between the illumination direction 2x and the imaging direction 4x is expressed as a parallax displacement θ Ｏ The correspondence relationship acquired during initial aiming is determined based on the parallax shift θ between the irradiation direction 2x and the imaging direction 4x during initial aiming. Ｏ and stored in the storage medium 18. When the correction unit 28 receives a trigger signal from the ignition switch 30 or the like and detects that the above-mentioned predetermined timing has arrived, the correction unit 28 calculates the deviation angle θ between the irradiation direction 2x and the imaging direction 4x based on the detection result obtained from the irradiation direction sensor 12. ｄ Then, the parallax displacement θ Ｏ In this way, when the irradiation direction 2x is changed, the change amount can be reflected in the correspondence.

[0061] Figures 5(A), 5(B), 5(C), and 5(D) are diagrams illustrating light distribution control involving a process for correcting the correspondence relationship. When the irradiation direction 2x is changed, the relative positional relationship between the imaging area 4a and the light distribution pattern PTN changes, as shown in Figure 5(A). In this state, a processing area ROI is extracted from the image IMG as shown in Figure 5(B), and a light spot image IMGa is generated as shown in Figure 5(C). Then, as shown in Figure 5(D), a shading portion 44 is set in the area of ​​the light distribution pattern PTN that corresponds to the target.

[0062] When setting the shading portion 44, the light distribution control device 6 uses information on the corrected correspondence relationship to determine the position of the shading portion 44. As a result, the shading portion 44 can be determined at a position (the position shown by the solid line in FIG. 5D ) that is shifted in a direction that cancels out the deviation between the target and the shading portion 44 by an amount corresponding to the change in the irradiation direction 2x from the position (the position shown by the chain line in FIG. 5D ) of the shading portion 44 that would be determined based on the correspondence relationship before the change in the irradiation direction 2x.

[0063] The light distribution control by the light distribution control device 6 of this embodiment is, at least temporarily, as follows. That is, for the same target at the same position relative to the vehicle, when the imaging direction 4x and the irradiation direction 2x have a first correspondence relationship with respect to the target, with the imaging direction 4x with respect to the target fixed, the light distribution control device 6 determines the shading portion 44 at a first position in the light distribution pattern PTN. On the other hand, when the imaging direction 4x and the irradiation direction 2x have a second correspondence relationship that is different from the first correspondence relationship, the light distribution control device 6 determines the shading portion 44 at a second position in the light distribution pattern PTN that is shifted from the first position. If the correspondence relationship between the imaging direction 4x and the irradiation direction 2x is not corrected, the position of the shading portion 44 in the light distribution pattern PTN does not change even if the irradiation direction 2x changes, as long as the position of the target in the image IMG does not change.

[0064] Alternatively, when the imaging direction 4x and the irradiation direction 2x are in a first correspondence relationship with respect to the same target at the same position relative to the vehicle and the target is at a third position in the imaging area 4a, the light distribution control device 6 determines the shading portion 44 at a first position in the light distribution pattern PTN. Furthermore, when the imaging direction 4x changes due to a change in the vehicle attitude or the like, while the irradiation direction 2x is maintained, the imaging direction 4x and the irradiation direction 2x are in a second correspondence relationship and the target shifts to a fourth position different from the third position in the imaging area 4a, the light distribution control device 6 also determines the shading portion 44 at the first position in the light distribution pattern PTN. If the correspondence relationship between the imaging direction 4x and the irradiation direction 2x is not corrected, the position of the shading portion 44 in the light distribution pattern PTN changes if the position of the target in the image IMG changes, even if the irradiation direction 2x does not change.

[0065] This embodiment also includes a computer program executed by the light distribution control device 6. This computer program acquires a detection result from the irradiation direction sensor 12 that detects the amount of change in the irradiation direction 2x, and causes the light distribution control device 6 to perform a function of determining, when the irradiation direction 2x is changed, a position of the light blocking portion 44 that is shifted by an amount corresponding to the amount of change from the position of the light blocking portion 44 that would be determined based on the correspondence relationship before the change. This embodiment also includes a storage medium 18 that stores the computer program.

[0066] 6 is a flowchart illustrating an example of control executed by the light distribution control device 6. This flow is repeatedly executed at predetermined timings when an instruction to execute ADB control is given by a light switch (not shown), for example, and the ignition is on.

[0067] First, the light distribution control device 6 acquires an image IMG from the imaging device 4 (S101). Then, the light distribution control device 6 determines whether a trigger signal has been received (S102). If a trigger signal has been received (Y in S102), the light distribution control device 6 corrects the correspondence information stored in the storage medium 18 (S103). If a trigger signal has not been received (N in S102), the light distribution control device 6 proceeds to step S104 without correcting the correspondence information.

[0068] Next, the light distribution control device 6 extracts a processing region ROI from the image IMG and generates a light spot image IMGa from the processing region ROI (S104). The light distribution control device 6 performs a target detection process using the generated light spot image IMGa (S105). Then, based on the results of the target detection process, it determines whether a target exists (S106). If a target exists (Y in S106), the light distribution control device 6 controls the variable light distribution lamp 2 to form a light distribution pattern PTN that includes the shading portion 44 (S107), and ends this routine. If a target does not exist (N in S106), the light distribution control device 6 controls the variable light distribution lamp 2 to form a light distribution pattern PTN that does not include the shading portion 44 (S108), and ends this routine.

[0069] As described above, when the irradiation direction 2x of the variable light distribution lamp 2 is changed, the light distribution control device 6 according to this embodiment determines the position of the shading portion 44 to be shifted by an amount corresponding to the change from the position of the shading portion 44 that would have been determined if the irradiation direction 2x and the imaging direction 4x had corresponded to each other before the change. In this way, by correcting the position of the shading portion 44 according to the amount of change in the irradiation direction 2x, it is possible to reduce the misalignment between the target and the shading portion 44. As a result, even when the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets, it is possible to form the shading portion 44 with high precision, thereby improving the accuracy of ADB control.

[0070] Furthermore, the light distribution control device 6 stores information about the correspondence relationship in a storage medium 18, and corrects the information about the correspondence relationship to reflect the change in the irradiation direction 2x at a timing determined based on the state of at least one of the ignition switch, vehicle speed, shift position, accelerator, and stand ST. The timing described above is likely to be immediately after the irradiation direction 2x is changed. Therefore, it is possible to more reliably perform highly accurate ADB control while preventing unnecessary correction of the correspondence relationship.

[0071] (Embodiment 2) The lighting system 1 according to this embodiment differs from embodiment 1 in that the imaging direction 4x is variable. The following description of the lighting system 1 according to this embodiment will focus on the configurations that are different from embodiment 1, and common configurations will be explained briefly or omitted. Figure 7 is a block diagram of the lighting system 1 according to embodiment 2. In Figure 7, the components of the lighting system 1 are depicted as functional blocks, similar to Figure 1.

[0072] The lighting system 1 of this embodiment includes a first aiming screw 40 and an imaging direction sensor 14 in addition to the components included in the lighting system 1 of Embodiment 1. By rotating the first aiming screw 40, the attitude of the first bracket 8 can be changed up, down, left, or right, and therefore the imaging direction 4x of the imaging device 4 can be changed up, down, left, or right. In other words, the first bracket 8 of this embodiment supports the imaging device 4 so that the imaging direction 4x can be changed. Furthermore, the first bracket 8 can be displaced independently of the second bracket 10.

[0073] The imaging direction sensor 14 can detect the amount of change in the imaging direction 4x (amount of change in angle). The imaging direction sensor 14 may be disposed inside or outside the lamp chamber. The imaging direction sensor 14 includes, for example, a known potentiometer, and can detect the amount of change in the imaging direction 4x from the amount of rotation (rotation angle) of the first aiming screw 40. The imaging direction sensor 14 sends a signal indicating the detection result to the control unit 16. Note that the imaging direction sensor 14 may also send the amount of rotation of the first aiming screw 40 itself (a voltage corresponding to the amount of rotation) to the control unit 16 as information indicating the amount of change in the imaging direction 4x.

[0074] The structure and method for changing the imaging direction 4x are not limited to those using the first aiming screw 40, and other known structures and methods can be adopted. Furthermore, the method for detecting the amount of change by the imaging direction sensor 14 can be selected appropriately depending on the structure and method for changing the imaging direction 4x.

[0075] When at least one of the irradiation direction 2x and the imaging direction 4x is changed, the light distribution control device 6 determines the position of the shading portion 44 at a position that is shifted from the position of the shading portion 44 determined based on the correspondence before the change by an amount corresponding to the change in the irradiation direction 2x and the change in the imaging direction 4x. When the irradiation direction 2x and the imaging direction 4x are displaced away from each other, the amount corresponding to these change amounts is the sum of the respective change amounts (absolute values). On the other hand, when the irradiation direction 2x and the imaging direction 4x are displaced toward each other, the amount corresponding to these change amounts is the difference between the respective change amounts (absolute values). As a result, even in a configuration in which both the irradiation direction 2x and the imaging direction 4x can be changed, the position of the shading portion 44 can be corrected according to the change amounts of both, and the shading portion 44 can be formed with high precision.

[0076] The above describes the embodiments of the present invention in detail. The above-described embodiments merely illustrate specific examples of implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the inventive concept defined in the claims. A new embodiment incorporating design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, design modifications that are possible are emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in areas without such notation. Any combination of the above components is also valid as an aspect of the present invention. Hatching in cross sections in the drawings does not limit the materials of the hatched objects.

[0077] The inventions according to the first and second embodiments described above may be specified by the following items: [Item 1] An illumination device including an imaging device (4) that images an area ahead of a vehicle, a variable light distribution lamp (2) capable of forming a light distribution pattern (PTN) having a shading portion (44), a first bracket (8) that supports the imaging device (4), a second bracket (10) that supports the variable light distribution lamp (2) so that the illumination direction (2x) can be changed and that is displaceable independently of the first bracket (8), an illumination direction sensor (12) that detects an amount of change in the illumination direction (2x), and a light distribution control device (6) that detects a target using an image (IMG) based on the imaging device (4), determines a position of a shading portion (44) corresponding to the target based on a correspondence between the imaging direction (4x) and the illumination direction (2x) of the imaging device (4), and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having the shading portion (44), When the irradiation direction (2x) is changed, the light distribution control device (6) determines the position of the shading portion (44) at a position that is shifted by an amount corresponding to the amount of change from the position of the shading portion (44) that would have been determined based on the correspondence before the change. [Item 2] The light distribution control device (6) stores information on the correspondence, corrects the information based on the amount of change at least one of when the ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range, and when the accelerator is switched from an off state to an on state, and determines the position of the shading portion (44) using the corrected information. [Item 3] The lighting system (1) is mounted on a saddle-type vehicle having a stand (ST) that supports a vehicle body (BD), and the light distribution control device (6) holds information on the correspondence relationship, corrects the information based on the amount of change when the stand (ST) switches from an upright position to a retracted position, and determines the position of the light blocking portion (44) using the corrected information. This is the lighting system (1) described in item 1 or 2.[Item 4] The lighting system (1) described in any of Items 1 to 3, wherein the first bracket (8) supports the imaging device (4) so ​​that the imaging direction (4x) can be changed, and is displaceable independently of the second bracket (10), the lighting system (1) includes an imaging direction sensor (14) that detects the amount of change in the imaging direction (4x), and the light distribution control device (6), when at least one of the irradiation direction (2x) and the imaging direction (4x) is changed, determines the shading part (44) at a position shifted by an amount corresponding to the amount of change in the irradiation direction (2x) and the amount of change in the imaging direction (4x) from the position of the shading part (44) determined based on the correspondence before the change. [Item 5] A light distribution control device (6) that detects a target using an image (IMG) based on an imaging device (4) that images the area in front of a vehicle, determines the position of a shading portion (44) corresponding to the target based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having the shading portion (44), wherein the light distribution control device (6) obtains a detection result from an irradiation direction sensor (12) that detects an amount of change in the irradiation direction (2x), and when the irradiation direction (2x) is changed, determines the shading portion (44) at a position shifted by an amount corresponding to the amount of change from the position of the shading portion (44) that would be determined based on the correspondence before the change. [Item 6] A light distribution control device (6) that detects a target using an image (IMG) based on an imaging device (4) that images an area in front of a vehicle, determines a position of a shading portion (44) corresponding to the target based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having the shading portion (44), wherein, for the same target at the same position relative to the vehicle, with the imaging direction (4x) relative to the target fixed, when the imaging direction (4x) and the irradiation direction (2x) are in a first correspondence relationship, the shading portion (44) is determined at a first position in the light distribution pattern (PTN), and when the imaging direction (4x) and the irradiation direction (2x) are in a second correspondence relationship different from the first correspondence relationship, the shading portion (44) is determined at a second position in the light distribution pattern (PTN) that is shifted from the first position.[Item 7] A computer program executed by a light distribution control device (6) that detects a target using an image (IMG) based on an imaging device (4) that images an area in front of a vehicle, determines a position of a shading portion (44) corresponding to the target based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having the shading portion (44), the computer program acquiring a detection result from an irradiation direction sensor (12) that detects an amount of change in the irradiation direction (2x), and, when the irradiation direction (2x) is changed, causing the light distribution control device (6) to perform a function of determining the shading portion (44) at a position shifted by an amount corresponding to the amount of change from the position of the shading portion (44) that would be determined based on the correspondence before the change.

[0078] (Embodiment 3) Fig. 1 is a block diagram of a lighting system 1 according to embodiment 3. In Fig. 1, the components of the lighting system 1 are depicted as functional blocks. These functional blocks are realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

[0079] The lighting system 1 includes a variable light distribution lamp 2, an imaging device 4, a light distribution control device 6, a first bracket 8, a second bracket 10, and an irradiation direction sensor 12. These are mounted on a vehicle. In this embodiment, the vehicle on which the lighting system 1 is mounted is, for example, a saddle-type vehicle such as a motorcycle.

[0080] The above-described variable light distribution lamp 2, image capture device 4, light distribution control device 6, first bracket 8, second bracket 10, and irradiation direction sensor 12 may all be housed in the same housing, or some of the mechanisms may be provided outside the housing. For example, the mechanisms may be housed in a lamp chamber. The lamp chamber is defined by a lamp body having an opening on the front side of the vehicle and a translucent cover attached to cover the opening of the lamp body.

[0081] The imaging device 4, light distribution control device 6, first bracket 8, and irradiation direction sensor 12 may be disposed outside the lamp chamber, for example, on the vehicle side. In this case, the imaging device 4 may be an on-board camera. If the imaging device 4 is an on-board camera, the vehicle body BD may correspond to the first bracket 8. Furthermore, the light distribution control device 6 may be configured, for example, in whole or in part, by a vehicle ECU.

[0082] The variable light distribution lamp 2 is capable of irradiating a visible light beam L1 with a variable intensity distribution toward a region ahead of the vehicle. The variable light distribution lamp 2 is capable of individually changing the illuminance of light irradiated onto multiple individual regions R arranged in the forward region. In other words, the variable light distribution lamp 2 is capable of irradiating the space ahead of the vehicle with light of different illuminances depending on the location (individual region R). The multiple individual regions R may be arranged, for example, in a line in the vehicle width direction or in a matrix. The variable light distribution lamp 2 receives information instructing a light distribution pattern PTN from the light distribution control device 6 and emits a visible light beam L1 having an intensity distribution corresponding to the light distribution pattern PTN. This forms the light distribution pattern PTN ahead of the vehicle. The light distribution pattern PTN can be understood as the two-dimensional illuminance distribution of an irradiation pattern 902 formed by the variable light distribution lamp 2 on a virtual vertical screen 900 ahead of the vehicle.

[0083] The variable light distribution lamp 2 may have any configuration, including, for example, a plurality of light sources arranged in a horizontal row or a matrix, and a lighting circuit that independently drives and lights each light source. Preferred examples of light sources include semiconductor light sources such as LEDs (light-emitting diodes), LDs (laser diodes), and organic or inorganic ELs (electroluminescence). Each individual region R is associated with a light source, and each light source individually irradiates each individual region R with light. The resolution of the variable light distribution lamp 2, or in other words, the light distribution resolution, is, for example, approximately 4 to 20 pixels when the light sources are arranged in a horizontal row, and approximately 1,000 to 2,000,000 pixels when the light sources are arranged in a matrix. The resolution of the variable light distribution lamp 2 refers to the number of unit regions whose illuminance can be independently changed in the light distribution pattern PTN.

[0084] In order to form an illuminance distribution according to the light distribution pattern PTN, the variable light distribution lamp 2 may include a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device, or a scanning optical pattern forming device that scans the area ahead of the vehicle with light from a light source. Also, a shade plate may be used to partially block light irradiation to the area ahead.

[0085] The imaging device 4 is, for example, a camera that is sensitive to the visible light region and repeatedly captures images of the area ahead of the vehicle. The imaging device 4 captures reflected light L2 of the visible light beam L1 by objects ahead of the vehicle. The imaging device 4 also captures light emitted by vehicles ahead, including leading and oncoming vehicles, as well as light emitted by self-luminous objects such as streetlights and electronic billboards. The image IMG generated by the imaging device 4 is sent to the light distribution control device 6.

[0086] The image IMG that the light distribution control device 6 acquires from the imaging device 4 may be RAW image data, or may be image data that has been subjected to predetermined image processing by the imaging device 4. In addition, the case in which the light distribution control device 6 receives image data in which RAW image data generated by the imaging device 4 has been subjected to image processing by a processing device other than the imaging device 4 also corresponds to acquisition of the image IMG from the imaging device 4. In the following description, "image IMG based on the imaging device 4" means that it may be either RAW image data or data that has been subjected to image processing. In addition, both types of image data may sometimes be expressed as "image IMG" without making a distinction between them.

[0087] The light distribution control device 6 detects a target using the image IMG based on the imaging device 4, and controls the variable light distribution lamp 2 to form a light distribution pattern PTN having a light-blocking portion corresponding to the detected target. In other words, the light distribution control device 6 performs ADB control, which dynamically and adaptively controls the light distribution of the variable light distribution lamp 2 according to targets present in the forward area. The light distribution control device 6 of this embodiment detects a vehicle ahead as the target. Note that the light distribution control device 6 may also detect targets other than a vehicle ahead. In this embodiment, the expression "corresponding to the target" of the light-blocking portion means that the light-blocking portion overlaps with the target when the light distribution pattern PTN is projected forward. The light distribution control device 6 sends information indicative of the light distribution pattern PTN to the variable light distribution lamp 2.

[0088] The light distribution control device 6 can be configured with a digital processor, for example, a combination of a microcomputer including a CPU and a software program. The light distribution control device 6 may also be configured with an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific IC).

[0089] The light distribution control device 6 includes a control unit 16 configured with a CPU or the like, and a storage medium 18 configured with memory and storage. The control unit 16 includes, by way of example, an area setting unit 20, a detection unit 22, a pattern determination unit 24, a lamp control unit 26, and a correction unit 28. The storage medium 18 stores computer programs executed by the light distribution control device 6 (more specifically, the control unit 16) and information on correspondence relationships, which will be described later. Each unit included in the control unit 16 operates when an integrated circuit that constitutes the unit executes a program stored in the storage medium 18. The operation of each unit will be described later.

[0090] The control unit 16 can also receive signals transmitted from an ignition switch 30, a vehicle speed sensor 32, a shift sensor 34, an accelerator sensor 36, and a stand sensor 38 mounted on the vehicle. The ignition switch 30 transmits a signal indicating whether the ignition is on or off to the control unit 16. The vehicle speed sensor 32 transmits a signal indicating the vehicle speed to the control unit 16. The shift sensor 34 transmits a signal indicating the shift position to the control unit 16. The accelerator sensor 36 transmits a signal indicating the amount of accelerator operation by the driver to the control unit 16. The stand sensor 38 transmits a signal to the control unit 16 indicating whether a stand ST supporting the vehicle body BD is in the upright position or the retracted position. The lighting system 1 may be mounted on a vehicle other than a saddle-type vehicle, such as a four-wheeled vehicle. In this case, the vehicle does not have a stand ST and a stand sensor 38.

[0091] The first bracket 8 supports the imaging device 4. The first bracket 8 of this embodiment supports the imaging device 4 so that the imaging direction 4x is immovable. The first bracket 8 has a known structure. The "imaging direction 4x" of the imaging device 4 can be rephrased as the "angle of the imaging axis" or "direction" of the imaging device 4.

[0092] The second bracket 10 supports the variable light distribution lamp 2 so that the irradiation direction 2x can be changed. The second bracket 10 has a known structure. As an example, the second bracket 10 has a second aiming screw 42. By rotating the second aiming screw 42, the position of the second bracket 10 can be changed up, down, left, or right, and therefore the irradiation direction 2x of the variable light distribution lamp 2 can be tilted up, down, left, or right. The "irradiation direction 2x" of the variable light distribution lamp 2 can be rephrased as the "angle of the optical axis" or "orientation" of the variable light distribution lamp 2.

[0093] The second bracket 10 can be displaced independently of the first bracket 8. Therefore, the correspondence between the imaging direction 4x and the irradiation direction 2x can change from the state set by the initial aiming performed at the vehicle manufacturer's manufacturing plant, a dealer's repair shop, or the like, due to displacement of the second bracket 10 that can occur during use of the vehicle.

[0094] The irradiation direction sensor 12 can detect the amount of change (amount of change in angle) in the irradiation direction 2x of the variable light distribution lamp 2. The irradiation direction sensor 12 includes, for example, a known potentiometer, and can detect the amount of change in the irradiation direction 2x from the amount of rotation (rotation angle) of the second aiming screw 42. The irradiation direction sensor 12 sends a signal indicating the detection result to the control unit 16. Note that the irradiation direction sensor 12 may also send the amount of rotation of the second aiming screw 42 itself (a voltage corresponding to the amount of rotation) to the control unit 16 as information indicating the amount of change in the irradiation direction 2x.

[0095] The structure and method for changing the irradiation direction 2x are not limited to those using the second aiming screw 42, and other known structures and methods may be employed. Furthermore, the method for detecting the amount of change by the irradiation direction sensor 12 may be appropriately selected depending on the structure and method for changing the irradiation direction 2x.

[0096] Next, the operation of the light distribution control device 6 will be described. Figures 2(A), 2(B), 2(C), and 2(D) are diagrams illustrating the basic operation of light distribution control. Figure 2(A) shows the imaging area 4a of the imaging device 4 and a light distribution pattern PTN formed in front of the vehicle. Here, a high beam light distribution pattern is shown as an example of the light distribution pattern PTN. Also, for convenience, Figure 2(A) illustrates a processing area ROI set in the image IMG (in other words, the imaging area 4a). The following description will be given using an oncoming vehicle 201 as an example of a target.

[0097] When an oncoming vehicle 201 is present ahead of the vehicle, an image IMG including the oncoming vehicle 201 is generated by the imaging device 4 and sent to the light distribution control device 6. The image IMG sent to the light distribution control device 6 is acquired by the region setting unit 20. The region setting unit 20 sets a processing region ROI for the image IMG. The processing region ROI is set based on the correspondence between the imaging direction 4x and the irradiation direction 2x. Information on this correspondence links position coordinates in the image IMG with position coordinates in the light distribution pattern PTN, and is created, for example, during initial aiming and stored in the storage medium 18.

[0098] The position where the processing region ROI should be set and the shape of the processing region ROI can be determined in advance based on experiments and simulations by a designer. For example, the processing region ROI is set in an area on the image IMG that overlaps with the irradiation range of the light distribution pattern PTN. The area on the image IMG that overlaps with the irradiation range of the light distribution pattern PTN is identified based on the correspondence relationship described above. Information on the processing region ROI includes position coordinates on the image IMG and is stored in advance in the storage medium 18. The image IMG in which the processing region ROI has been set is sent to the detection unit 22.

[0099] The detection unit 22 extracts a processing region ROI from the image IMG, as shown in FIG. 2B. Then, it performs known image processing, such as binarization, on the processing region ROI. As a result, a light spot image IMGa is generated, as shown in FIG. 2C, in which two light spots 202 corresponding to the lamps of the oncoming vehicle 201 are extracted. The lamps of the oncoming vehicle 201 are headlamps, etc. Note that when the detection target is a preceding vehicle, light spots 202 corresponding to the rear lamps, etc. of the preceding vehicle are included in the light spot image IMGa. The rear lamps include stop lamps and tail lamps.

[0100] The detection unit 22 determines the presence or absence of a target using the light spot image IMGa. Performing target detection processing on the light spot image IMGa corresponds to performing target detection processing on the image IMG or the processing region ROI. When a light spot 202 is included in the light spot image IMGa, the detection unit 22 detects a target based on the light spot 202. For example, the detection unit 22 determines that the light spot 202 present in the processing region ROI originates from a target, in other words, that a target exists at the position where the light spot 202 is present.

[0101] The detection unit 22 sends the detection result to the pattern determination unit 24. The target detection method implemented by the detection unit 22 is not particularly limited. For example, the generation of the light spot image IMGa may be omitted, and targets may be detected from the processing region ROI using a known method including algorithm recognition, deep learning, etc. The type of target (forward vehicle, oncoming vehicle 201, preceding vehicle, sign, etc.) may or may not be identified. The detection unit 22 can identify the type of target by the above-mentioned algorithm recognition or deep learning, or based on known judgment indices such as the position of the light spots 202 or whether the light spots 202 are paired (pairing).

[0102] When a target object is detected, the pattern determination unit 24 sets a shading portion 44 in an area corresponding to the target object in the base light distribution pattern, as shown in FIG. 2(D). This determines the light distribution pattern PTN to be formed. The shading portion 44 is a portion in the light distribution pattern PTN where the brightness (illuminance) is 0, or a portion where the brightness is greater than 0, that is, where the brightness is lower than before shading. When a target object is not detected, the pattern determination unit 24 determines a light distribution pattern PTN that does not have a shading portion 44.

[0103] The base light distribution pattern is selected according to a light distribution mode that is determined based on, for example, a driver's instruction via operation of a light switch (not shown), the driving state of the vehicle, the environment around the vehicle, etc. For example, the light distribution mode includes a high beam mode that forms a light distribution pattern for high beams, a low beam mode that forms a light distribution pattern for low beams, a town mode that forms a light distribution pattern suitable for driving in urban areas, etc. Figure 2(D) shows an example of a light distribution pattern for high beams.

[0104] The position of the shading portion 44 is determined based on the correspondence between the imaging direction 4x and the irradiation direction 2x. Based on this correspondence, the position of the shading portion 44 in the light distribution pattern PTN can be determined from the position of the target in the light spot image IMGa. As an example, the pattern determination unit 24 determines a shading portion 44 of a predetermined shape in the light distribution pattern PTN. Note that the pattern determination unit 24 may perform a known expansion / contraction process on the light spot image IMGa to deform the shape of the light spot 202, and use the deformed shape of the light spot 202 as the shape of the shading portion 44. The pattern determination unit 24 sends information about the determined light distribution pattern PTN to the lamp control unit 26.

[0105] The lamp control unit 26 instructs the variable light distribution lamp 2 to form a light distribution pattern PTN. The lamp control unit 26 is configured, for example, with a known LED driver module (LDM). If the dimming method of the light source of the variable light distribution lamp 2 is analog dimming, the lamp control unit 26 adjusts the DC level of the drive current flowing through the light source. If the dimming method of the light source is PWM (Pulse Width Modulation) dimming, the lamp control unit 26 adjusts the average level of the drive current by switching the current flowing through the light source and adjusting the ratio of the on period. If the variable light distribution lamp 2 has a DMD, the lamp control unit 26 controls the on / off switching of each mirror element constituting the DMD. If the variable light distribution lamp 2 has a liquid crystal device, the lamp control unit 26 controls the light transmittance of the liquid crystal device. As a result, the light distribution pattern PTN is formed in front of the vehicle.

[0106] Next, the position correction of the processing region ROI when the correspondence relationship between the irradiation direction 2x and the imaging direction 4x has changed since the initial aiming will be described. Figures 8(A), 8(B), 8(C), and 8(D) are diagrams illustrating a case where the basic operation is performed in a situation where the correspondence relationship between the irradiation direction 2x and the imaging direction 4x has changed since the initial aiming.

[0107] As described above, the light distribution control device 6 determines the processing region ROI in the image IMG based on the correspondence between the imaging direction 4x and the irradiation direction 2x. In this type of control, if the correspondence changes from that obtained during initial aiming, the processing region ROI and the irradiation range of the light distribution pattern PTN may become misaligned, and a situation may arise in which the light-shielding portion 44 cannot be superimposed on the target when the light distribution pattern PTN is irradiated.

[0108] For example, an auto-leveling function has been put into practical use for adjusting the irradiation direction 2x. In this case, if the vehicle posture changes due to loading of luggage or the like, the posture of the second bracket 10 is automatically changed by the auto-leveling function before the vehicle starts traveling. This adjusts the irradiation direction 2x to an angle that matches the vehicle posture. The irradiation direction 2x may also be changed manually.

[0109] If the variable light distribution lamp 2 and the imaging device 4 are mounted on the same bracket, the irradiation direction 2x can be changed while maintaining the correspondence between the irradiation direction 2x and the imaging direction 4x at the time of initial aiming. However, if the variable light distribution lamp 2 and the imaging device 4 are mounted on the same bracket, the bracket becomes large, and the location where the bracket can be installed may be limited. In this case, the degree of freedom in arranging the variable light distribution lamp 2 and the imaging device 4 is reduced. For this reason, it is desirable to mount the variable light distribution lamp 2 and the imaging device 4 on separate brackets, as in this embodiment.

[0110] When the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets, the imaging direction 4x is often fixed as in this embodiment. One reason for this is that the imaging range of the imaging device 4 is generally wider than the irradiation range of the variable light distribution lamp 2, and so even if the imaging direction 4x remains fixed, it is possible to capture the entire light distribution pattern PTN after the irradiation direction 2x has shifted. Therefore, when the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets, the correspondence between the irradiation direction 2x and the imaging direction 4x may change from the time of initial aiming.

[0111] When the illumination direction 2x is changed, the relative positional relationship between the image capture area 4a and the light distribution pattern PTN changes, as shown in FIG. 8A. In this state, a processing area ROI is set in the image IMG. In basic operation, the processing area ROI is set in the image IMG based on the correspondence created during initial aiming, so the processing area ROI is misaligned with the light distribution pattern PTN. In this case, as shown in FIG. 8B, even if an oncoming vehicle 201 is present within the image capture area 4a, the lamp of this oncoming vehicle 201 may fall outside the processing area ROI.

[0112] Therefore, as shown in Fig. 8(C), a light spot image IMGa that does not include the light spot 202 may be generated. Vehicle detection using this light spot image IMGa cannot detect the oncoming vehicle 201, even though the oncoming vehicle 201 actually exists. As a result, a light distribution pattern PTN that does not have the light-shielding portion 44 is determined, as shown in Fig. 8(D).

[0113] Therefore, when the irradiation direction 2x is changed, the light distribution control device 6 of this embodiment determines the processing area ROI at a position that is shifted by an amount corresponding to the change in the irradiation direction 2x from the position of the processing area ROI that would be determined based on the correspondence relationship before the change in the irradiation direction 2x.

[0114] As an example, the correction unit 28 of the light distribution control device 6 corrects the correspondence information based on the amount of change in the irradiation direction 2x at a predetermined timing, and stores the corrected information in the storage medium 18 as new correspondence information.

[0115] The predetermined timing may be at least one of when the ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range (for example, the drive range or first gear), and when the accelerator is switched from an off state to an on state. Furthermore, the lighting system 1 of this embodiment is mounted on a saddle-ride type vehicle. Therefore, the predetermined timing may also be when the stand ST is switched from the upright position to the retracted position.

[0116] The correction unit 28 performs the correction process of the correspondence relationship by receiving trigger signals indicating that a predetermined timing has occurred from the ignition switch 30, the vehicle speed sensor 32, the shift sensor 34, the accelerator sensor 36, and the stand sensor 38. The correction unit 28 may perform the correction process every time it obtains a detection result from the irradiation direction sensor 12.

[0117] The process of correcting the correspondence relationship based on the amount of change in the irradiation direction 2x can be performed as follows. Fig. 4 is a schematic diagram for explaining the method of correcting the correspondence relationship. As shown in Fig. 4, for example, when the variable light distribution lamp 2 and the image capture device 4 are mutually offset by x in the X-axis direction, ｄ shifted by y in the Y-axis direction ｄ The angle between the irradiation direction 2x (which coincides with the X axis) of the variable light distribution lamp 2 and the imaging direction 4x of the imaging device 4 is θ ｄ The deviation amount x between the installation positions of the variable light distribution lamp 2 and the image capture device 4 is ｄ , y ｄ is measured in advance and stored in the storage medium 18.

[0118] Assume that a target p exists on a virtual vertical screen 900 that is a distance x away from the variable light distribution lamp 2 in the X-axis direction. The target p is located at a distance x away from the variable light distribution lamp 2 in the X-axis direction and a distance y away from the irradiation direction 2x of the variable light distribution lamp 2. The angle of the target p when viewed from the variable light distribution lamp 2 is θ ｅ The angle of the target p when viewed from the imaging device 4 is θ ｃ Angle θ ｅ and angle θ ｃ The difference between the above is the parallax shift θ between the variable light distribution lamp 2 and the image capture device 4. Ｏ is.

[0119] The variable light distribution lamp 2 and the image capture device 4 are mutually x ｄ and y ｄ The irradiation direction 2x and the imaging direction 4x are offset by an angle θ ｄ In this case, the parallax deviation θ between the variable light distribution lamp 2 and the image capturing device 4 is Ｏ can be expressed by the following equation (1): Ｏ=atan(y / x)-[atan{(y-y ｄ ) / (x-x ｄ )-θ ｄ ]

[0120] If the X-axis direction is the front-rear direction of the variable light distribution lamp 2 and the imaging device 4, and the Y-axis direction is the up-down direction of the variable light distribution lamp 2 and the imaging device 4, the parallax shift θ in the up-down direction between the variable light distribution lamp 2 and the imaging device 4 is Ｏ Furthermore, if the X-axis direction is the front-rear direction of the variable light distribution lamp 2 and the imaging device 4, and the Y-axis direction is the left-right direction of the variable light distribution lamp 2 and the imaging device 4, then the parallax shift θ Ｏ can be calculated.

[0121] The correspondence between the illumination direction 2x and the imaging direction 4x is expressed as a parallax displacement θ Ｏ The correspondence relationship acquired during initial aiming is determined based on the parallax shift θ between the irradiation direction 2x and the imaging direction 4x during initial aiming. Ｏ and stored in the storage medium 18. When the correction unit 28 receives a trigger signal from the ignition switch 30 or the like and detects that the above-mentioned predetermined timing has arrived, the correction unit 28 calculates the deviation angle θ between the irradiation direction 2x and the imaging direction 4x based on the detection result obtained from the irradiation direction sensor 12. ｄ Then, the parallax displacement θ Ｏ In this way, when the irradiation direction 2x is changed, the change amount can be reflected in the correspondence.

[0122] 9(A), 9(B), 9(C), and 9(D) are diagrams illustrating light distribution control involving a process for correcting the correspondence relationship. When the irradiation direction 2x is changed, the relative positional relationship between the imaging area 4a and the light distribution pattern PTN changes, as shown in FIG. 9(A). In this state, a processing region ROI is set. Then, the processing region ROI is extracted from the image IMG, as shown in FIG. 9(B). When setting the processing region ROI, the light distribution control device 6 determines the position of the processing region ROI using information on the corrected correspondence relationship. This allows the processing region ROI to be set at a position (shown by a solid line in FIG. 9(A)) that is shifted from the position of the processing region ROI determined based on the correspondence relationship before the irradiation direction 2x was changed (shown by a dashed line in FIG. 9(A)) in a direction that cancels out the deviation between the processing region ROI and the light distribution pattern PTN by an amount corresponding to the change in the irradiation direction 2x.

[0123] Therefore, as shown in Fig. 9(C), the light spot image IMGa generated from this processing region ROI can include two light spots 202 corresponding to the lamps of the oncoming vehicle 201. As a result, as shown in Fig. 9(D), a light distribution pattern PTN including a shading portion 44 overlapping with the oncoming vehicle 201 can be formed in front of the vehicle. As an example, the pattern determination unit 24 determines the shading portion 44 in the light distribution pattern PTN based on the information on the corrected correspondence relationship.

[0124] The light distribution control by the light distribution control device 6 of this embodiment is performed at least temporarily as follows. That is, for the same target at the same position relative to the vehicle, when the imaging direction 4x and the irradiation direction 2x have a first correspondence relationship with respect to the target while the imaging direction 4x with respect to the target is fixed, the light distribution control device 6 determines the shading portion 44 in the light distribution pattern PTN. On the other hand, when the imaging direction 4x and the irradiation direction 2x have a predetermined second correspondence relationship different from the first correspondence relationship, the light distribution control device 6 does not determine the shading portion 44 in the light distribution pattern PTN. The second correspondence relationship is, for example, the relationship between the imaging direction 4x and the irradiation direction 2x when the target is deviated from the light distribution pattern PTN. If the correspondence relationship between the imaging direction 4x and the irradiation direction 2x is not corrected and the position of the target in the image IMG does not change, the target will remain located within the processing region ROI, and the shading portion 44 will be set in the light distribution pattern PTN even if the irradiation direction 2x changes and the target deviates from the light distribution pattern PTN.

[0125] Alternatively, for the same target object at the same position relative to the vehicle, when the imaging direction 4x and the irradiation direction 2x have a first correspondence relationship and the target object is within the processing region ROI, the light distribution control device 6 sets the shading portion 44 in the light distribution pattern PTN. Furthermore, when the imaging direction 4x changes due to a change in the vehicle attitude or the like, causing the target object to move out of the processing region ROI when the first correspondence relationship was established, while the irradiation direction 2x is maintained, resulting in a predetermined second correspondence relationship between the imaging direction 4x and the irradiation direction 2x, the light distribution control device 6 also sets the shading portion 44 in the light distribution pattern PTN. If the correspondence relationship between the imaging direction 4x and the irradiation direction 2x is not corrected, and the imaging direction 4x shifts and the target object moves out of the processing region ROI when the first correspondence relationship was established, the shading portion 44 is not set in the light distribution pattern PTN even if the irradiation direction 2x does not shift and the target object is within the irradiation range of the light distribution pattern PTN.

[0126] This embodiment also includes a computer program executed by the light distribution control device 6. This computer program acquires detection results from the irradiation direction sensor 12 that detects the amount of change in the irradiation direction 2x, and causes the light distribution control device 6 to perform a function of determining, when the irradiation direction 2x is changed, setting the processing region ROI at a position that is shifted by an amount corresponding to the amount of change from the position of the processing region ROI that would be determined based on the correspondence before the change. This embodiment also includes a storage medium 18 that stores this computer program.

[0127] 6 is a flowchart illustrating an example of control executed by the light distribution control device 6. This flow is repeatedly executed at predetermined timings when an instruction to execute ADB control is given by a light switch (not shown), for example, and the ignition is on.

[0128] First, the light distribution control device 6 acquires an image IMG from the imaging device 4 (S101). Then, the light distribution control device 6 determines whether a trigger signal has been received (S102). If a trigger signal has been received (Y in S102), the light distribution control device 6 corrects the correspondence information stored in the storage medium 18 (S103). If a trigger signal has not been received (N in S102), the light distribution control device 6 proceeds to step S104 without correcting the correspondence information.

[0129] Next, the light distribution control device 6 extracts a processing region ROI from the image IMG using the correspondence information and generates a light spot image IMGa from the processing region ROI (S104). The light distribution control device 6 performs a target detection process using the generated light spot image IMGa (S105). Then, based on the result of the target detection process, it determines whether a target exists (S106). If a target exists (Y in S106), the light distribution control device 6 controls the variable light distribution lamp 2 to form a light distribution pattern PTN that includes the shading portion 44 (S107), and ends this routine. If a target does not exist (N in S106), the light distribution control device 6 controls the variable light distribution lamp 2 to form a light distribution pattern PTN that does not include the shading portion 44 (S108), and ends this routine.

[0130] As described above, when the irradiation direction 2x of the variable light distribution lamp 2 is changed, the light distribution control device 6 according to this embodiment determines the processing region ROI at a position that is shifted by an amount corresponding to the change from the position of the processing region ROI that would have been determined if the irradiation direction 2x and the imaging direction 4x had corresponded to each other before the change. By correcting the position of the processing region ROI in accordance with the amount of change in the irradiation direction 2x, the light blocking portion 44 can be formed with high precision even when the variable light distribution lamp 2 and the imaging device 4 are mounted on separate brackets. This improves the accuracy of ADB control.

[0131] Furthermore, the light distribution control device 6 stores information about the correspondence relationship in a storage medium 18, and corrects the information about the correspondence relationship to reflect the change in the irradiation direction 2x at a timing determined based on the state of at least one of the ignition switch, vehicle speed, shift position, accelerator, and stand ST. The timing described above is likely to be immediately after the irradiation direction 2x is changed. Therefore, it is possible to more reliably perform highly accurate ADB control while preventing unnecessary correction of the correspondence relationship.

[0132] (Embodiment 4) The lighting system 1 according to this embodiment differs from embodiment 3 in that the imaging direction 4x is variable. The following description of the lighting system 1 according to this embodiment will focus on the configurations that are different from embodiment 3, and common configurations will be explained briefly or omitted. Figure 7 is a block diagram of the lighting system 1 according to embodiment 4. In Figure 7, the components of the lighting system 1 are depicted as functional blocks, similar to Figure 1.

[0133] The lighting system 1 of this embodiment includes a first aiming screw 40 and an imaging direction sensor 14 in addition to the components included in the lighting system 1 of embodiment 3. By rotating the first aiming screw 40, the attitude of the first bracket 8 can be changed up, down, left, or right, and therefore the imaging direction 4x of the imaging device 4 can be changed up, down, left, or right. In other words, the first bracket 8 of this embodiment supports the imaging device 4 so that the imaging direction 4x can be changed. Furthermore, the first bracket 8 can be displaced independently of the second bracket 10.

[0134] The imaging direction sensor 14 can detect the amount of change in the imaging direction 4x (amount of change in angle). The imaging direction sensor 14 may be disposed inside or outside the lamp chamber. The imaging direction sensor 14 includes, for example, a known potentiometer, and can detect the amount of change in the imaging direction 4x from the amount of rotation (rotation angle) of the first aiming screw 40. The imaging direction sensor 14 sends a signal indicating the detection result to the control unit 16. Note that the imaging direction sensor 14 may also send the amount of rotation of the first aiming screw 40 itself (a voltage corresponding to the amount of rotation) to the control unit 16 as information indicating the amount of change in the imaging direction 4x.

[0135] The structure and method for changing the imaging direction 4x are not limited to those using the first aiming screw 40, and other known structures and methods can be adopted. Furthermore, the method for detecting the amount of change by the imaging direction sensor 14 can be selected appropriately depending on the structure and method for changing the imaging direction 4x.

[0136] When at least one of the irradiation direction 2x and the imaging direction 4x is changed, the light distribution control device 6 determines the processing region ROI at a position shifted by an amount corresponding to the change in the irradiation direction 2x and the change in the imaging direction 4x from the position of the processing region ROI determined based on the correspondence before the change. When the irradiation direction 2x and the imaging direction 4x are displaced away from each other, the amount corresponding to these change amounts is the sum of the respective change amounts (absolute values). On the other hand, when the irradiation direction 2x and the imaging direction 4x are displaced toward each other, the amount corresponding to these change amounts is the difference between the respective change amounts (absolute values). As a result, even in a configuration in which both the irradiation direction 2x and the imaging direction 4x can be changed, the position of the processing region ROI can be corrected according to the change amounts of both, and the light-shielding portion 44 can be formed with high precision.

[0137] The above describes the embodiments of the present invention in detail. The above-described embodiments merely illustrate specific examples of implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the inventive concept defined in the claims. A new embodiment incorporating design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, design modifications that are possible are emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in areas without such notation. Any combination of the above components is also valid as an aspect of the present invention. Hatching in cross sections in the drawings does not limit the materials of the hatched objects.

[0138] The inventions according to the third and fourth embodiments described above may be specified by the following items: [Item 1] An image capturing device (4) capturing an image ahead of a vehicle, an adjustable light distribution lamp (2) capable of forming a light distribution pattern (PTN) having a shading portion (44), a first bracket (8) supporting the image capturing device (4), a second bracket (10) supporting the adjustable light distribution lamp (2) so as to be able to change an irradiation direction (2x) and being displaceable independently with respect to the first bracket (8), an irradiation direction sensor (12) detecting an amount of change in the irradiation direction (2x), and a light distribution control device (6) that sets a processing region (ROI) for an image (IMG) based on the image capturing device (4) based on a correspondence between the image capturing direction (4x) and the irradiation direction (2x) of the image capturing device (4), performs a target detection process for the processing region (ROI) to detect a target, and controls the adjustable light distribution lamp (2) to form a light distribution pattern (PTN) having a shading portion (44) corresponding to the target, A lighting system (1) in which, when the irradiation direction (2x) is changed, the light distribution control device (6) determines a processing region (ROI) at a position shifted by an amount corresponding to the change from the position of the processing region (ROI) determined based on the correspondence before the change. [Item 2] The lighting system (1) in which the light distribution control device (6) stores information on the correspondence, corrects the information based on the amount of change at least one of when the ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range, and when the accelerator is switched from an off state to an on state, and determines the position of the processing region (ROI) using the corrected information. [Item 3] The lighting system (1) is mounted on a saddle-type vehicle having a stand (ST) that supports a vehicle body (BD), and the light distribution control device (6) holds information on the correspondence relationship, corrects the information based on the amount of change when the stand (ST) switches from an upright position to a retracted position, and determines the position of a processing region (ROI) using the corrected information. This is the lighting system (1) described in item 1 or 2.[Item 4] The lighting system (1) described in any of items 1 to 3, wherein the first bracket (8) supports the imaging device (4) so ​​that the imaging direction (4x) can be changed, and is displaceable independently of the second bracket (10), the lighting system (1) includes an imaging direction sensor (14) that detects the amount of change in the imaging direction (4x), and the light distribution control device (6), when at least one of the irradiation direction (2x) and the imaging direction (4x) is changed, determines the processing region (ROI) at a position shifted by an amount corresponding to the amount of change in the irradiation direction (2x) and the amount of change in the imaging direction (4x) from the position of the processing region (ROI) determined based on the correspondence before the change. [Item 5] A light distribution control device (6) that sets a processing region (ROI) for an image (IMG) based on an imaging device (4) that images the area in front of a vehicle, based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), performs target detection processing on the processing region (ROI) to detect a target, and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having a shading portion (44) that corresponds to the target, wherein the light distribution control device (6) obtains a detection result from an irradiation direction sensor (12) that detects an amount of change in the irradiation direction (2x), and when the irradiation direction (2x) is changed, determines the processing region (ROI) at a position shifted by an amount corresponding to the amount of change from the position of the processing region (ROI) that would be determined based on the correspondence before the change.[Item 6] A light distribution control device (6) that sets a processing region (ROI) for an image (IMG) based on an imaging device (4) that images an area in front of a vehicle based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), performs target detection processing for the processing region (ROI) to detect the target, and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having a shading portion (44) corresponding to the target, wherein, for the same target at the same position relative to the vehicle, with the imaging direction (4x) relative to the target fixed, when the imaging direction (4x) and the irradiation direction (2x) are in a first correspondence relationship, the light distribution control device (6) determines the shading portion (44) in the light distribution pattern (PTN), and when the imaging direction (4x) and the irradiation direction (2x) are in a predetermined second correspondence relationship different from the first correspondence relationship, the light distribution control device (6) does not determine the shading portion (44) in the light distribution pattern (PTN). [Item 7] A computer program executed by a light distribution control device (6) that sets a processing region (ROI) for an image (IMG) based on an imaging device (4) that images an area in front of a vehicle based on a correspondence between an imaging direction (4x) of the imaging device (4) and an irradiation direction (2x) of a variable light distribution lamp (2), performs target detection processing on the processing region (ROI) to detect the target, and controls the variable light distribution lamp (2) to form a light distribution pattern (PTN) having a shading portion (44) that corresponds to the target, the computer program acquiring a detection result from an irradiation direction sensor (12) that detects an amount of change in the irradiation direction (2x), and, when the irradiation direction (2x) is changed, causing the light distribution control device (6) to perform a function of determining the processing region (ROI) at a position shifted by an amount corresponding to the amount of change from the position of the processing region (ROI) that would be determined based on the correspondence before the change.

[0139] The present invention can be used in a lighting system, a light distribution control device, and a computer program.

[0140] 1 lighting system, 2 variable light distribution lamp, 2x irradiation direction, 4 imaging device, 4x imaging direction, 6 light distribution control device, 8 first bracket, 10 second bracket, 12 irradiation direction sensor, 14 imaging direction sensor, 44 shading portion, PTN light distribution pattern, ROI processing area.

Claims

1. A lighting system comprising: an imaging device for imaging the area in front of a vehicle; a variable light distribution lamp capable of forming a light distribution pattern having a shading portion; a first bracket for supporting said imaging device; a second bracket for supporting said variable light distribution lamp so that the irradiation direction can be changed and which is displaceable independently of said first bracket; an irradiation direction sensor for detecting an amount of change in said irradiation direction; and a light distribution control device for detecting a target object using an image based on said imaging device, determining a position of a shading portion corresponding to said target object based on a mutual correspondence between the imaging direction of said imaging device and the irradiation direction, and controlling said variable light distribution lamp to form a light distribution pattern having said shading portion, wherein when the irradiation direction is changed, said light distribution control device determines the shading portion at a position shifted by an amount corresponding to the amount of change from the position of the shading portion determined based on the correspondence before the change.

2. The lighting system of claim 1, wherein the light distribution control device retains information of the correspondence relationship, corrects the information based on the amount of change at least one of when an ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range, and when the accelerator is switched from an off state to an on state, and determines the position of the light-shielding portion using the corrected information.

3. The lighting system of claim 1, wherein the lighting system is mounted on a saddle-type vehicle equipped with a stand that supports the vehicle body, and the light distribution control device retains information on the correspondence relationship, corrects the information based on the amount of change when the stand is switched from an upright position to a retracted position, and determines the position of the light-shielding part using the corrected information.

4. A lighting system as described in any one of claims 1 to 3, wherein the first bracket supports the imaging device so that the imaging direction can be changed and is displaceable independently of the second bracket, the lighting system is equipped with an imaging direction sensor that detects an amount of change in the imaging direction, and the light distribution control device, when at least one of the irradiation direction and the imaging direction is changed, determines the shading part at a position shifted by an amount corresponding to the amount of change in the irradiation direction and the amount of change in the imaging direction from the position of the shading part determined based on the correspondence before the change.

5. A light distribution control device that detects a target object using an image based on an imaging device that captures an image of the area in front of a vehicle, determines the position of a shading part corresponding to the target object based on a correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, and controls the variable light distribution lamp to form a light distribution pattern having the shading part, wherein the light distribution control device obtains a detection result from an irradiation direction sensor that detects an amount of change in the irradiation direction, and when the irradiation direction is changed, determines the shading part at a position shifted by an amount corresponding to the amount of change from the position of the shading part determined based on the correspondence before the change.

6. A light distribution control device that detects a target using an image based on an imaging device that images the area in front of a vehicle, determines a position of a light-blocking section corresponding to the target based on a mutual correspondence between the imaging direction of the imaging device and the irradiation direction of a light distribution variable lamp, and controls the light distribution variable lamp to form a light distribution pattern having the light-blocking section, wherein, for the same target in the same position relative to the vehicle, with the imaging direction relative to the target fixed, when the imaging direction and the irradiation direction have a first correspondence, the light-blocking section is determined at a first position in the light distribution pattern, and when the imaging direction and the irradiation direction have a second correspondence different from the first correspondence, the light-distribution control device determines the light-blocking section at a second position shifted from the first position in the light distribution pattern.

7. A computer program executed by a light distribution control device that detects a target using an image based on an imaging device that captures an image of the area in front of a vehicle, determines a position of a shading part corresponding to the target based on a correspondence between the imaging direction of the imaging device and the irradiation direction of a light distribution variable lamp, and controls the light distribution control device to form a light distribution pattern having the shading part, the computer program acquiring a detection result from an irradiation direction sensor that detects an amount of change in the irradiation direction, and, when the irradiation direction is changed, causing the light distribution control device to perform a function of determining the shading part at a position shifted by an amount corresponding to the amount of change from the position of the shading part determined based on the correspondence before the change.

8. A lighting system comprising: an imaging device for imaging an area in front of a vehicle; a variable light distribution lamp capable of forming a light distribution pattern having a light-shielding portion; a first bracket for supporting said imaging device; a second bracket for supporting said variable light distribution lamp so that the irradiation direction can be changed and which is displaceable independently of said first bracket; an irradiation direction sensor for detecting an amount of change in said irradiation direction; and a light distribution control device for setting a processing area based on a correspondence between the imaging direction of said imaging device and the irradiation direction for an image based on said imaging device, performing a target detection process on said processing area to detect said target, and controlling said variable light distribution lamp to form a light distribution pattern having a light-shielding portion corresponding to said target, wherein when the irradiation direction is changed, said light distribution control device determines the processing area to a position shifted by an amount corresponding to the amount of change from the position of the processing area determined based on the correspondence before the change.

9. The lighting system of claim 8, wherein the light distribution control device retains information of the correspondence relationship, corrects the information based on the amount of change at least one of when an ignition switch is switched from an off state to an on state, when the vehicle speed exceeds 0, when the shift position is switched from the neutral range to another range, and when the accelerator is switched from an off state to an on state, and determines the position of the processing area using the corrected information.

10. The lighting system of claim 8, wherein the lighting system is mounted on a saddle-type vehicle having a stand that supports the vehicle body, and the light distribution control device retains information of the correspondence, corrects the information based on the amount of change when the stand is switched from an upright position to a retracted position, and determines the position of the processing area using the corrected information.

11. A lighting system as described in any one of claims 8 to 10, wherein the first bracket supports the imaging device so that the imaging direction can be changed and is displaceable independently of the second bracket, the lighting system is provided with an imaging direction sensor that detects an amount of change in the imaging direction, and the light distribution control device, when at least one of the irradiation direction and the imaging direction is changed, determines the processing area at a position shifted by an amount corresponding to the amount of change in the irradiation direction and the amount of change in the imaging direction from the position of the processing area determined based on the correspondence before the change.

12. A light distribution control device that sets a processing area for an image based on an imaging device that captures an image in front of a vehicle based on the mutual correspondence between the imaging direction of the imaging device and the irradiation direction of a variable light distribution lamp, performs target detection processing on the processing area to detect the target, and controls the variable light distribution lamp to form a light distribution pattern having a shading portion corresponding to the target, wherein the detection result is obtained from an irradiation direction sensor that detects the amount of change in the irradiation direction, and when the irradiation direction is changed, the light distribution control device determines the processing area at a position shifted by an amount corresponding to the amount of change from the position of the processing area determined based on the correspondence before the change.

13. A light distribution control device that sets a processing area for an image based on an imaging device that captures an image in front of a vehicle based on the mutual correspondence between the imaging direction of the imaging device and the irradiation direction of a light distribution variable lamp, performs target detection processing for the processing area to detect the target, and controls the light distribution variable lamp to form a light distribution pattern having a shading portion corresponding to the target, wherein, for the same target at the same position relative to the vehicle, with the imaging direction relative to the target fixed, when the imaging direction and the irradiation direction are in a first correspondence relationship, the light distribution control device determines the shading portion in the light distribution pattern, and when the imaging direction and the irradiation direction are in a predetermined second correspondence relationship different from the first correspondence relationship, the light distribution control device does not determine the shading portion in the light distribution pattern.

14. A computer program executed by a light distribution control device that sets a processing area for an image based on an imaging device that captures an image in front of a vehicle based on the mutual correspondence between the imaging direction of the imaging device and the irradiation direction of a light distribution variable lamp, performs target detection processing on the processing area to detect the target, and controls the light distribution control device to form a light distribution pattern having a shading portion corresponding to the target, the computer program acquiring a detection result from an irradiation direction sensor that detects an amount of change in the irradiation direction, and, when the irradiation direction is changed, causes the light distribution control device to execute a function of determining the processing area at a position shifted by an amount corresponding to the amount of change from the position of the processing area determined based on the correspondence before the change.

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