Control device for a vehicle headlight, vehicle headlight system

Abstract

Provision is made to reduce problems in visual detection associated with the movement of a dimming (or light-shielding) area. A control device for a vehicle headlight, wherein the control device controls the operation of the vehicle headlight with a variable light distribution pattern, wherein, when a first region is generated in which the dimming range, which is set at a first time, is switched to the light emission range at a second time, and / or when a second region is generated in which the light emission range, which is set at a first time, is switched to the dimming range at a second time, the control device is configured to define an emission range that gradually changes the brightness of each of the regions, wherein the control device generates a control signal for output to the vehicle headlight based on the emission mode.The emission mode shows a temporal change in which the magnitude of the change in brightness in the vicinity of a starting point and in the vicinity of an endpoint is less than the magnitude of the change in brightness in the middle between the starting point and the endpoint.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a control device for a vehicle headlight and to a vehicle headlight system. TECHNICAL BACKGROUND

[0002] A technique for controlling the light distribution of a vehicle headlight, primarily within the emission range of a high beam, is usually known to reduce or dim a certain area according to the position of another vehicle in front of the vehicle (a vehicle ahead, an oncoming vehicle, or similar). For example, the unexamined Japanese patent application with publication number 2022-139713 (patent document 1) describes a vehicle lighting system in which an attenuation or dimming area is defined according to the position of a vehicle ahead, and in which an extended dimming area is defined at one of the left or right sides of a dimming area according to the direction of movement of the vehicle ahead in the lateral direction of the vehicle. In this vehicle lighting system, the attenuation or dimming is controlled with respect to a certain time orof a time range, when the brightness of the segment corresponding to the extended dimming range is changed, this time or time range is set comparatively shorter when the speed of movement of the front vehicle in the lateral direction of the vehicle increases, and it is set comparatively longer when the speed of movement decreases. DOCUMENTS ON THE STATE OF THE TECHNOLOGY PATENT DOCUMENT

[0003] Patent document 1: unexamined Japanese patent application with publication number 2022-139713. SUMMARY OF THE INVENTIONAL PROBLEM

[0004] In one specific aspect, an objective of the present disclosure is to provide a technique capable of reducing difficulties in visual detection associated with the movement of a dimming area (or a light-shielding area). SOLUTION TO THE PROBLEM (1) A control device for a vehicle headlight according to one aspect of the present disclosure is a control device for a vehicle headlight in which the device controls an operation of the vehicle headlight which has a variable light distribution pattern, comprising: a control device connected to the vehicle's headlight, wherein the control device is configured to define a light distribution pattern which has a dimming area corresponding to the position of a front vehicle, further a halftone area located adjacent to the dimming area, and a light emission area located adjacent to the halftone area, wherein, if a first region is created in which the dimming area containing the light distribution pattern set at a first time is switched to the light emission area at a second time following the first time, and / or if a second region is created in which the light emission area containing the light distribution pattern set at the first time is switched to the dimming area at the second time, the control device is configured to set an emission mode that gradually changes the brightness of the first region and / or the second region, wherein, based on the defined light distribution pattern and emission mode specified for the first region and / or the second region, the control device generates a control signal for output to the vehicle headlight, and wherein the emission mode exhibits a temporal change, wherein the magnitude of the change in brightness in the vicinity of a starting point and in the vicinity of an endpoint is smaller than the magnitude of a change in brightness at the midpoint between the starting point and the endpoint. (2) A vehicle headlight system according to one aspect of the present disclosure is a vehicle headlight system comprising the following: the control device for a vehicle headlight in accordance with point (1) described above and a vehicle headlight connected to the control device.

[0005] According to the above configurations, a technique is provided that is capable of reducing problems in visual detection associated with the movement of the dimming area (or a light-shielding area). BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1(A) is a figure illustrating a configuration of a vehicle headlight system according to an exemplary embodiment. Fig. 1(B) is a diagram illustrating the configuration of a computer system. Fig. Figure 2(A) is a figure illustrating a light distribution pattern which is variably defined. Fig. 2(B) is a figure illustrating an example of regions for variable light distribution to variably define a light distribution pattern. Fig. Figure 3 is a diagram to explain temporal changes in the light emission area in each region for variable light distribution. Fig. 4(A) and Fig. Figures 4(B) are illustrations that depict temporal changes in brightness in a region for variable light distribution. Fig. Figure 5 is a diagram that schematically shows the movement of the dimming area that can be visually perceived. Fig. 6(A) and Fig. Figure 6(B) shows illustrations to explain the speed of movement of the dimming area. Fig. Figure 7 is a flowchart illustrating an operating procedure of the vehicle headlight system. Fig. 8(A) and Fig. Figures 8(B) are illustrations showing modified examples of temporal changes in brightness in a region for variable light distribution. WAY TO IMPLEMENTING THE INVENTION

[0006] Fig. Figure 1(A) is a figure illustrating a configuration of a vehicle headlight system according to an exemplary embodiment. The illustrated vehicle headlight system is configured to include a control device 10, a camera 11, and a pair of headlight units 12L and 12R. This vehicle headlight system is designed to emit light forward from the vehicle. In the present description, a control device for a vehicle headlight is configured to include the control device 10.

[0007] The control device 10 controls the operation or process of light emission emitted by each of the headlight units 12L and 12R. For example, the control device 10 can be configured to use a computer system, such as that found in Fig. Figure 1(B) illustrates a computer system comprising a processor (CPU: Central Processing Unit) 201, a read memory or ROM (ROM = Read Only Memory) 202, a working memory or RAM (RAM = Random Access Memory) 203, a storage device 204, such as flash memory, an input / output interface 205, and so on. The control device 10 of the present embodiment is in a state in which a program 206, previously stored in the storage device 204, is read and executed by the processor, so that each of the functions described below can be performed.

[0008] Camera 11 performs predefined image recognition processing based on image data obtained by photographing the area in front of the vehicle, thereby detecting the position of a vehicle ahead (a vehicle driving ahead, an oncoming vehicle), a pedestrian, and so on. Here, some or all of the image recognition processing functions can be located on the control device 10. In such a case, image recognition processing is performed by supplying image data from camera 11 to the control device 10 and by executing a predefined program within the control device 10.

[0009] The control device 10 comprises, as functional blocks which are realized by program execution, a vehicle detection unit 20, a light distribution pattern determination unit 21, a determination unit 22 for gradual or gradual change and a control signal generation unit 23.

[0010] The vehicle detection unit 20 detects information indicating the actual position of the vehicle in front or similar, based on the detection result of the vehicle in front or similar by the camera 11.

[0011] The light distribution pattern setting unit 21 sets a light distribution pattern of the emitted light to be emitted by each of the headlight units 12L and 12R, based on the detection result of a front vehicle or similar by the vehicle detection unit 20. The light distribution pattern of the present embodiment has an attenuation or dimming region (or a light shielding region, the same being true later), which is set as a specific region in accordance with the position of the front vehicle, a light emission region, which is set to a region in which the front vehicle does not exist, and a halftone region, which is set in the lateral direction of the vehicle adjacent to the dimming region.

[0012] With regard to the light distribution pattern defined by the light distribution pattern setting unit 21, the gradual change setting unit 22 defines the mode of temporal change (hereinafter referred to as the "emission mode") of the brightness (illuminance or luminance) in the region transitioning from the light emission area to the dimming area. Furthermore, the gradual change setting unit 22 defines the emission mode of the brightness in the region transitioning from the dimming area to the light emission area. Additionally, in this embodiment, the gradual change setting unit 22 defines whether or not the brightness in the gradual change area is changed over time according to the vehicle's speed of movement in the lateral direction of the dimming area when the light distribution pattern is switched.

[0013] The control signal generation unit 23 generates a control signal to cause each of the headlight units 12L and 12R to form a beam pattern according to the light distribution pattern defined by the light distribution pattern setting unit 21 and according to the beam mode defined by the gradual change setting unit 22, and supplies the control signal to each of the headlight units 12L and 12R.

[0014] The pair of headlight units 12L and 12R is mounted at predetermined positions on the left and right sides of the front of the vehicle and operates in accordance with a control signal supplied by the control device 10 to shape a light emitted forward from the vehicle. The headlight units 12L and 12R of this embodiment can each shape a low beam (pass-by light) and a high beam (driving light) and can variably define the light distribution pattern within the high beam's emission range.

[0015] Various known configurations can be used as headlight units 12L and 12R. For example, a high beam, a low beam, and an additional beam can be formed by a single lamp unit that combines a light source valve, a reflector, and a shielding plate. Furthermore, an adaptive driving light beam can be formed using a lamp unit with light-emitting elements, such as LEDs, arranged in one or two directions, where the lamp unit is capable of individually controlling the illumination state of each of the light-emitting elements.Furthermore, an adaptive headlight beam can be formed using a lamp unit comprising a light source and a liquid crystal element, wherein the lamp unit is capable of individually controlling the light transmission state of each pixel of the liquid crystal element. It is also possible to form an adaptive headlight beam using a lamp unit comprising a light-emitting element, such as a laser diode, and a guide or scan element, such as a mirror device, for guiding or scanning light emitted by the light-emitting element, wherein the lamp unit is capable of controlling the timing of the switching on and off of the light-emitting element and the timing of the guide or scan operation by the scan element.Furthermore, in the lamp unit that has these configurations, a high beam beam and a low beam beam can be formed in addition to the adaptive driving light beam.

[0016] Fig. Figure 2(A) illustrates a variable light distribution pattern. The illustrated light distribution pattern is formed on the screen or projection surface when the projection surface is assumed to be at a predetermined position in front of the vehicle (for example, 30 m in front). In the vehicle headlight system of the present embodiment, a light distribution pattern is defined within the area of ​​a light emission region 150 of the high beam beam. This light distribution pattern includes a dimming region 151 corresponding to the position of a vehicle 102 in front and halftone regions 152 arranged adjacent to the dimming region 151. The emitted light based on the defined light distribution pattern is directed forward from the vehicle.As illustrated, the light distribution pattern is updated so that the positions of the dimming area 151 and the halftone areas 152 change in response to a change in vehicle position when the position of the front vehicle 102 changes over time.

[0017] In light emission range 150, for example, the emitted light is controlled to have a predetermined maximum brightness. In dimming range 151, the emitted light is controlled to reduce its brightness to a predetermined minimum value (typically zero). In halftone range 152, the emitted light is controlled to have an intermediate brightness between that of light emission range 150 and dimming range 151. As a result, this allows the viewer to perceive the emitted light as changing with respect to the gradation from light emission range 150 to dimming range 151.

[0018] Fig. Figure 2(B) illustrates an example of variable light distribution regions for variably defining a light distribution pattern. The illustrated variable light distribution regions R comprise a total of 40 regions arranged in 4 rows and 10 columns, and the light emission state of each region can be individually and variably defined. By controlling the light emission state in some regions of the variable light distribution regions R according to the position and apparent size of the vehicle in front, the emitted light of the light distribution pattern, which includes the dimming region 151 and the halftone region 152 as described above, can be shaped. Here, the number of variable light distribution regions R and the shape of each variable light distribution region R are not limited to those illustrated in the example.Each region R for variable light distribution with a different shape in a top view can be used, or the number of regions R for variable light distribution can be increased or decreased.

[0019] Fig. Figure 3 is a diagram illustrating temporal changes in the light emission state in each region for variable light distribution. For simplicity, ten regions within a row of regions R for variable light distribution are shown, and the reference symbols R1 to R10 are used to distinguish the regions within the shown regions R for variable light distribution. In practice, this represents a light emission area, a dimming area, and a halftone area in the light distribution pattern; that in Fig. 2(A) is illustrated and described above, each configured by combining a number of variable light distribution regions. In the figure, the variable light distribution region shown by thick hatching represents a dimming region, the variable light distribution region shown by thin hatching represents a halftone region, and the variable light distribution region shown without hatching represents a light emission region.

[0020] As indicated by arrows in the drawings, and if, for example, the focus is on region R3 for variable light distribution from time T0 through time T1 to time T2, region R3 for variable light distribution is a light emission area at time T0, and as the time changes from T0 to T2, region R3 for variable light distribution becomes a light dimming area at time T2, specifically over a halftone range. In this case, the temporal change in brightness (illuminance or luminance) in region R3 for variable light distribution is controlled to follow a sigmoid curve, as shown in the diagram. Fig. 4(A) shown. The sigmoid curve referred to here is generally a curve drawn by a function expressed as follows: y=1 / (1+e−ax).

[0021] Similarly, for example, if attention is focused on region R2 for variable light distribution from time T2 to time T4 over time T3, region R2 for variable light distribution is a dimming region at time T2, and when the time changes from T2 to T4, region R2 for variable light distribution becomes a light emission region at time T4, over a halftone range. In this case, the temporal change in brightness (luminance or luminance) of region R2 for variable light distribution is also controlled to follow a sigmoid curve, as shown in Fig. 4(B) is shown as an example.

[0022] Here, the temporal change in brightness is not limited to the sigmoid curve, but can be any curve where the magnitude of the change in brightness (degree of change) in the vicinity of the starting point and in the vicinity of the endpoint is smaller than the magnitude of the change (degree of change) midway between the starting point and the endpoint. In particular, for example, a temporal change in brightness can be realized along a curve (tertiary curve or third-degree curve) represented by a tertiary function or third-degree function, such as y = a x3 + b x2+ cx, or any other curve can be used. The "neighborhood of the starting point," as used here, refers, for example, to the period extending from the starting point to the endpoint that is less than or equal to one-quarter of the total length between the starting point and the endpoint. Similarly, the "neighborhood of the endpoint" refers, for example, to the period extending from the endpoint back to the starting point, extending a length equal to or less than one-quarter of the total distance between the starting point and the endpoint.

[0023] When each region R for variable light distribution switches from the dimming range to the light emission range or vice versa, as described above, the brightness changes gradually based on the sigmoid curve or a similar curve, rather than switching instantly. This can give the viewer the impression that the resolution of the region R for variable light distribution has pseudo-increased. Although each region R for variable light distribution is actually the smallest unit of light distribution change, the movement of the dimming range, in particular, appears smoother with a higher resolution than the actual resolution, as shown in Fig. 5 illustrates.

[0024] According to research carried out by the inventors of the present application, it has been found that, although it is more effective to gradually change the brightness when the movement speed of the dimming area is relatively slow, this effect tends to be difficult to perceive, depending on the movement speed of the dimming area. The “movement speed of the dimming area,” as used here, can in principle be expressed as the magnitude of the change in the movement distance L of the dimming area per unit time, as in Fig. 6(A) shown.

[0025] In an actual control system, as in Fig. As shown in Figure 6(B), the speed of motion can also be expressed as the magnitude of the change in angle θ. LThe dimming range per unit time must be expressed, since the position of the dimming range is often described by a relative angle based on the predetermined position p of the vehicle itself. For example, when the latter angle expression is used, a study by the inventors of the present application has found that by using a value of, for example, 10° / second as a threshold, it is possible to appropriately determine whether or not a gradual change in brightness should be used.

[0026] This means that if the dimming range's movement speed is less than 10° / second, it is determined that the movement speed is slow, and a gradual brightness change process is effective. Conversely, if the dimming range's movement speed is 10° / second or greater, it is determined that the movement speed is fast, and therefore the gradual brightness change process is not implemented, thus reducing the computational load required for brightness control.

[0027] Fig. Figure 7 is a flowchart illustrating an operating procedure of the vehicle headlight system. It should be noted that the sequence of processes shown here can be changed as long as no contradictions or inconsistencies arise in the result of the information processing, and other processes not explicitly described here can also be added.

[0028] When the vehicle detection unit 20 of the control device 10 detects a front vehicle (step S11), the light distribution pattern determination unit 21 determines a light distribution pattern according to the position of the front vehicle (step S12).

[0029] Next, the gradual change setting unit 22 calculates the movement speed of the dimming area (step S13). This calculation is based on the position of the dimming area at the time of the previous processing and the position of the dimming region set in the current step S12. It should be noted that if the dimming area is not present at the time of the previous processing, such as at the time of the initial processing, an extraordinary processing action is performed, such as setting the movement speed to zero.

[0030] If the movement speed of the dimming area obtained in step S13 is less than a predetermined threshold (for example, 10° / second) (step S14: NO), the gradual change setting unit 22 sets the gradual change brightness operation to "Execute gradual change operation" (step S15).

[0031] On the other hand, if the movement speed of the dimming area obtained in step S13 is equal to or greater than the predetermined threshold (step S14; YES), the gradual change setting unit 22 sets the gradual change brightness operation to "Do not perform gradual change operation" (step S16).

[0032] Next, the control signal generation unit 23 generates a control signal so that emitted light is formed in accordance with the light distribution pattern defined by the light distribution pattern setting unit 21, with or without processing the gradual change defined by the gradual change setting unit 22, and sends the control signal to each of the headlight units 12L and 12R (step S17). The procedure then returns to step S11, and the subsequent operations are repeated.

[0033] According to the embodiment described above, it is possible to reduce problems in visual detection that are related to the movement of the dimming area (or the light-shielding area).

[0034] It should be noted that the present invention is not limited to the content of the embodiment described above and can be modified in various ways and implemented within the scope of this disclosure. For example, in the embodiment described above, temporal changes in brightness (illuminance or luminance) in the regions for variable light distribution are examples where the rise time (see Fig. 4(B)) and the waste disposal time (see Fig. 4(A)) are fixed to the same length, however the rise time T can on and the waste time T off be fixed at different lengths, as in Fig. 8(A) and Fig. 8(B) shown. In this case, as shown in the example, it is preferable to set the rise time T. on to set it so that it is shorter than the waste time T off .

[0035] Furthermore, in the embodiment described above, the question of whether or not to perform processing for gradual brightness changes is determined based on the movement speed of the dimming area. However, whether or not to perform processing for gradual brightness changes can also be determined based on the apparent movement speed of the vehicle in front relative to the vehicle in the lateral direction. In this case, the movement speed can be obtained by calculating the rate of change of the position of the vehicle in front per unit time in the same way as in the case of the dimming area described above (see Fig. 6(A) and Fig. 6(B)).

[0036] The present invention has features as set out in the appendices below. (Appendix 1)

[0037] A control device for a vehicle headlight, wherein the device controls an operation of the vehicle headlight which has a variable light distribution pattern, comprising the following: a control device connected to the vehicle's headlight, wherein the control device is configured to define a light distribution pattern which has an attenuation or dimming area according to the position of a front vehicle, further a halftone area located adjacent to the dimming area, and a light emission area located adjacent to the halftone area, wherein, if a first region is generated in which the dimming area contained in the light distribution pattern defined at a first time is switched to the light emission area at a second time following the first time, and / or if a second region is generated in which the light emission area contained in the light distribution pattern defined at the first time is switched to the dimming area at the second time, the control device is configured to define an emission mode that gradually changes the brightness of the first region and / or the second region, wherein, based on the defined light distribution pattern and emission mode specified for the first region and / or the second region, the control device generates a control signal for output to the vehicle headlight, and where the emission mode exhibits a temporal change in which the magnitude of the change in brightness in the neighborhood of a starting point and in the neighborhood of an endpoint is smaller than the magnitude of the change in brightness at the midpoint between the starting point and the endpoint. (Appendix 2)

[0038] The control device for a vehicle headlight according to Appendix 1 where the emission mode shows a temporal change in brightness along a sigmoid curve or tertiary curve or third-degree curve. (Appendix 3)

[0039] The control device for a vehicle headlight according to Appendix 1 or 2, wherein the control device is configured to achieve a movement speed of the dimming area from the first time to the second time; to set the first region and / or the second region to broadcast mode if the movement speed is less than a predetermined threshold; and not to set the first region and / or the second region to broadcast mode if the movement speed is equal to or greater than the predetermined threshold. (Appendix 4)

[0040] The control device for a vehicle headlight according to Appendix 1 or 2, wherein the control device is configured to determine a movement speed of the front vehicle in its vehicle width direction from the first time to the second time; to set the first region and / or the second region to broadcast mode if the movement speed is less than a predetermined threshold; and not to set the first region and / or the second region to broadcast mode if the movement speed is equal to or greater than the predetermined threshold. (Appendix 5)

[0041] The control device for a vehicle headlight according to Appendix 3 or 4, where the predetermined threshold is 10° / second when expressed as an angle based on a predetermined position of one's own vehicle. (Appendix 6)

[0042] The control device for a vehicle headlight according to one of Appendices 1 to 5, where the emission mode is set such that a fall time, in which the brightness is reduced, is comparatively longer than a rise time, in which the brightness is increased. (Appendix 7)

[0043] A control method for a vehicle headlight, wherein the method controls an operation of the vehicle headlight which has a variable light distribution pattern, and wherein the method comprises the following: (a) Defining by a control device a light distribution pattern which has an attenuation or dimming area according to the position of a front vehicle, further a halftone area which is adjacent to the dimming area and a light emission area which is adjacent to the halftone area, (b) Setting by the control device, when a first region is generated in which the dimming range contained in the light distribution pattern set at a first time is switched to the light emission range at a second time following the first time, and / or when a second region is generated in which the light emission range contained in the light distribution pattern set at the first time is switched to the dimming range at the second time, an emission mode that gradually changes the brightness of the first region and / or the second region, and (c) Generating a control signal by the control device for output to the vehicle headlight, based on the light distribution pattern defined by the above in (a) and the emission mode defined for the first region and / or the second region defined by the above in (b), and wherein the emission mode defined by the above description in (b) exhibits a temporal change in which the magnitude of the change in brightness in the neighborhood of a starting point and in the neighborhood of an endpoint is smaller than the magnitude of the change in brightness at the midpoint between the starting point and the endpoint. (Appendix 8)

[0044] A vehicle headlight system which features the following: the control device for a vehicle headlight according to one of Appendices 1 to 7, and a vehicle headlight connected to the control device. REFERENCE MARK LIST 10 Control device 11 Camera 12L, 12R Headlight Unit 20 vehicle detection units 21 Light distribution pattern definition unit 22 Unit of measurement for gradual or gradual change 23 Control signal generation unit 102 front vehicle 150 light emission range 151 Dimming range or attenuation range R, R1 to R10 region for variable light distribution

Claims

[1] Control device for a vehicle headlight, wherein the device controls an operation of the vehicle headlight which has a variable light distribution pattern, comprising the following: a control device connected to the vehicle's headlight, wherein the control device is configured to define a light distribution pattern which has an attenuation or dimming area according to the position of a front vehicle, further a halftone area located adjacent to the dimming area, and a light emission area located adjacent to the halftone area, wherein, if a first region is generated in which the dimming area contained in the light distribution pattern defined at a first time is switched to the light emission area at a second time following the first time, and / or if a second region is generated in which the light emission area contained in the light distribution pattern defined at the first time is switched to the dimming area at the second time, the control device is configured to define an emission mode that gradually changes the brightness of the first region and / or the second region, wherein, based on the defined light distribution pattern and emission mode specified for the first region and / or the second region, the control device generates a control signal for output to the vehicle headlight, and where the emission mode exhibits a temporal change in which the magnitude of the change in brightness in the neighborhood of a starting point and in the neighborhood of an endpoint is smaller than the magnitude of the change in brightness at the midpoint between the starting point and the endpoint. [2] Control device for a vehicle headlight according to claim 1, wherein the emission mode exhibits a temporal change in brightness along a sigmoid curve or tertiary curve or third-degree curve. [3] Control device for a vehicle headlight according to claim 1, wherein the control device is configured to achieve a movement speed of the dimming area from the first time to the second time; to set the first region and / or the second region to the emission mode when the movement speed is less than a predetermined threshold; and not to set the first region and / or the second region to the emission mode when the movement speed is equal to or greater than the predetermined threshold. [4] Control device for a vehicle headlight according to claim 1, wherein the control device is configured to determine a movement speed of the front vehicle in its vehicle width direction from the first time to the second time; to set the first region and / or the second region to the emission mode when the movement speed is less than a predetermined threshold; and not to set the first region and / or the second region to the emission mode when the movement speed is equal to or greater than the predetermined threshold. [5] Control device for a vehicle headlight according to claim 3 or 4, wherein the predetermined threshold is 10° / second when expressed as an angle based on a predetermined position of the vehicle itself. [6] Control device for a vehicle headlight according to claim 1, wherein the emission mode is set such that a fall time in which the brightness is reduced is comparatively longer than a rise time in which the brightness is increased. [7] Control method for a vehicle headlight, wherein the method controls an operation of the vehicle headlight which has a variable light distribution pattern, the method comprising the following: (a) Defining by a control device a light distribution pattern which has an attenuation or dimming area according to the position of a front vehicle, further a halftone area which is adjacent to the dimming area and a light emission area which is adjacent to the halftone area, (b) Setting by the control device, when a first region is generated in which the dimming range contained in the light distribution pattern set at a first time is switched to the light emission range at a second time following the first time, and / or when a second region is generated in which the light emission range contained in the light distribution pattern set at the first time is switched to the dimming range at the second time, an emission mode that gradually changes the brightness of the first region and / or the second region, and (c) Generating a control signal by the control device for output to the vehicle headlight, based on the light distribution pattern defined by the above in (a) and the emission mode defined for the first region and / or the second region defined by the above in (b), wherein the emission mode defined by the above in (b) exhibits a temporal change in which the magnitude of the change in brightness in the neighborhood of a starting point and in the neighborhood of an endpoint is less than the magnitude of the change in brightness at the midpoint between the starting point and the endpoint. [8] Vehicle headlight system which includes the following: the control device for a vehicle headlight according to claim 1, and a vehicle headlight connected to the control device.

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