JP2017192115A - Visible recognition apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a visible recognition apparatus for vehicle, capable of achieving high visibility by suppressing generation of fluctuations in the brightness of a picked-up image even after light flashing occurs around a vehicle.SOLUTION: The visible recognition apparatus for vehicle includes: a rear camera for adjusting an exposure according to the brightness of an area around a vehicle and photographing the area; a monitor for displaying a picked-up image; and a controller 18 for detecting light flashing around a vehicle by a lighting instruction signal of a turn lamp switch and controlling, when the light flashing is detected, the rear camera to maintain an exposure adjustment value at a mean value between an exposure adjustment value obtained when light is irradiated and an exposure adjustment value obtained when light is not irradiated.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicular visual recognition device for photographing a vehicle periphery and displaying a captured image in order to visually recognize the vehicle periphery.

  2. Description of the Related Art A vehicular visual recognition device is known in which a photographing unit and a display unit are mounted on a vehicle and a photographed image obtained by photographing the periphery of the vehicle with a photographing unit is displayed on the display unit.

  In this type of vehicular visual recognition device, when there is light that repeats blinking, such as light from a turn lamp, the exposure at the time of photographing changes due to the blinking light. In the shooting section, exposure adjustment is performed by automatic exposure adjustment, but in the case of light that periodically blinks, automatic exposure adjustment is adjusted after the blinking of the light, so it may be overexposed or underexposed, Since the brightness of the image fluctuates, it becomes difficult to see the image.

  Therefore, in Patent Document 1, in a vehicle imaging device that images a left front side of a vehicle by providing a camera and a lamp on a left side mirror, in order to prevent halation due to blinking of the turn lamp, the lamp has a phase opposite to that of the turn lamp. It has been proposed to light up. Patent Document 1 proposes that the gain of an image signal captured when the turn lamp is lit is reduced and the gain of the image signal is increased when the turn lamp is not lit.

JP 2005-178657 A

  However, in Patent Document 1, since the lamp is turned on in the opposite phase to the turn lamp, there is a possibility that the turn lamp is difficult to recognize from the outside, so there is room for improvement.

  Japanese Patent Application Laid-Open No. 2004-228561 also proposes adjusting the gain of the image signal, but the exposure is adjusted in accordance with the blinking of the turn lamp, and the screen is switched, making it difficult to view the image.

  The present invention has been made in consideration of the above facts, and provides a vehicular visual recognition device capable of improving visibility by suppressing fluctuations in brightness of a captured image even when light blinks around the vehicle. The purpose is to do.

  In order to achieve the above object, the invention according to claim 1 displays a photographing unit that photographs the periphery of the vehicle by adjusting exposure according to the brightness around the vehicle, and a photographed image photographed by the photographing unit. A display unit, a detection unit that detects flashing of light around the vehicle, an exposure adjustment value when light is irradiated when the detection unit detects flashing of light, and a case where light is not irradiated A control unit that controls the photographing unit so as to maintain an exposure adjustment value between the exposure adjustment value and the exposure adjustment value.

  According to the first aspect of the present invention, the photographing unit performs exposure adjustment according to the brightness around the vehicle to photograph the vehicle periphery, and the display unit captures a photographed image of the vehicle periphery photographed by the photographing unit. Is displayed.

  The detector detects blinking of light around the vehicle. For example, the detection unit detects blinking of light by a turn lamp of the host vehicle or another vehicle.

  Then, the control unit maintains an exposure adjustment value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated when blinking of the light is detected by the detection unit. Thus, the photographing unit is controlled. Thereby, even if the blinking of light occurs, the exposure adjustment value is maintained at the exposure adjustment value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated, Variations in brightness of the captured image can be suppressed. Therefore, even if blinking of light occurs around the vehicle, it becomes possible to improve visibility by suppressing fluctuations in brightness of the captured image.

  As in the second aspect of the invention, the detection unit may detect blinking of light by detecting a turn lamp blinking instruction signal. Thereby, blinking of the light of the turn lamp of the host vehicle can be detected. Alternatively, as in the third aspect of the invention, the detection unit detects the blinking of the light by detecting the light around the vehicle or the periodic change of the exposure adjustment value at the time of shooting of the shooting unit. Also good. As a result, it is possible to detect not only the own vehicle but also the blinking of the turn lamps of other vehicles and the blinking of other lights.

  Further, as in the invention described in claim 4, the control unit detects a predetermined dark environment, and when the dark environment is detected, the exposure is smaller than the exposure adjustment value maintained when the dark environment is not detected. The photographing unit may be further controlled so as to maintain the adjustment value. This makes it possible to improve the visibility of the captured image in a dark environment such as at night.

  As described above, according to the present invention, it is possible to provide a vehicular visual recognition device capable of improving visibility by suppressing fluctuations in brightness of a captured image even when light flashes around the vehicle. There is an effect.

(A) is a figure which shows the vehicle mounting position example of the visual recognition apparatus for vehicles which concerns on this embodiment, (B) is a figure which shows schematic structure of the visual recognition apparatus for vehicles. It is a block diagram which shows the structure of the control system of the visual recognition apparatus for vehicles which concerns on this embodiment. (A) is a figure which shows the periodic change of ON / OFF of a light source, (B) is a figure which shows the periodic change of an exposure adjustment value, (C) is exposure adjustment when light is irradiated. It is a figure which shows the example which maintained the intermediate value of the value and the exposure adjustment value when light is not irradiated. (A) is a figure which shows the example of an image when the blink of light has not generate | occur | produced around the vehicle, (B) is a figure which shows the example which the whole image became white by overexposure, (C) is exposure. It is a figure which shows the example by which the whole image was crushed black by under. It is a flowchart which shows an example of the flow of the process performed with the control apparatus of the visual recognition apparatus for vehicles which concerns on this embodiment. It is a block diagram which shows the structure of the control system of the visual recognition apparatus for vehicles of a modification. It is a flowchart which shows an example of the flow of the process performed with the control apparatus of the visual recognition apparatus for vehicles of a modification.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1A is a diagram illustrating an example of a vehicle mounting position of the vehicle visual recognition device according to the present embodiment, and FIG. 1B is a diagram illustrating a schematic configuration of the vehicle visual recognition device.

  The vehicular visual recognition device 10 according to the present embodiment includes a rear side camera 12 as an imaging unit, a monitor 14 as a display unit, an operation unit 16, and a control device 18 as a detection unit and a control unit. The rear side camera 12, the monitor 14, and the control device 18 are provided corresponding to the left and right sides of the vehicle.

  The rear side camera 12 is installed outside at the front side end of the vehicle in the vertical direction middle part of the side door (front side door, not shown) of the vehicle and photographs the rear side of the vehicle. The rear side camera 12 is provided in a substantially rectangular parallelepiped box-shaped housing 13 as a support, and a lens is arranged toward the rear side of the vehicle to photograph the rear side of the vehicle. The vehicle width direction inner side end part of the housing | casing 13 is attached to the side door, and the housing | casing 13 is supported by the side door (vehicle body side) so that rotation in the vehicle front-back direction is possible. In addition, the housing | casing 13 is good also as a form attached to other positions, such as a front fender, instead of a side door.

  The monitor 14 is provided in the vicinity of the lower end of the front pillar, and mainly displays an image captured by the rear side camera 12 as a visual image. In other words, the rear side of the vehicle as the vehicle periphery can be visually recognized by checking the monitor 14 instead of the outer mirror. The monitors 14 are provided corresponding to the left and right sides of the vehicle.

  The operation unit 16 gives an instruction to change the display position of the image displayed on the monitor 14, that is, the rear side viewing range. The operation unit 16 includes, for example, a switch or a sensor for performing an instruction to change the visual range in the vehicle width direction, an instruction to change the vehicle in the vertical direction, or the monitor 14 (left or right) to be changed in the visual range. A switch or the like for instructing is provided. Specifically, it includes a left switch 16L and a right switch 16R for instructing a direction corresponding to the monitor 14 that changes the viewing range, and a direction instruction unit 16S for instructing the change direction.

  The control device 18 is provided corresponding to each of the left and right sides of the vehicle, and performs display control of captured images of the left and right rear side cameras 12. The control device 18 changes the viewing range on the rear side of the vehicle when reversing to make it easier to visually recognize obstacles on the lower side of the vehicle, and sets the viewing range in conjunction with the operation of the direction indicator. You may make it change and carry out turning interlocking control etc. which make it easy to visually recognize the vehicle rear side.

  Then, the structure of the control system of the visual recognition apparatus 10 for vehicles which concerns on this embodiment is demonstrated. FIG. 2 is a block diagram illustrating a configuration of a control system of the vehicle visual recognition device 10 according to the present embodiment.

  The control device 18 includes a microcomputer in which a CPU 18A, a ROM 18B, a RAM 18C, and an I / O (input / output interface) 18D are connected to a bus 18E.

  The ROM 18B stores various programs such as a visual image control program for displaying a captured image of the rear side of the rear side camera 12 on the monitor 14. The program stored in the ROM 18B is expanded in the RAM 18C and executed by the CPU 18A, whereby the photographing control of the rear side camera 12 and the display control on the monitor 14 are performed.

  The I / O 18D is connected with an operation unit 16, a rear side camera 12, a monitor 14, and a turn lamp switch 20 for instructing a change in the viewing range.

  The operation unit 16 outputs a change instruction signal to the control device 18 when an instruction to change the rear side viewing range is given by the occupant. Specifically, the operation unit 16 includes the above-described left switch 16L, right switch 16R, and direction instruction unit 16S illustrated in FIG. That is, the direction (left or right) corresponding to the monitor 14 whose viewing range is changed is instructed by the left switch 16L or the right switch 16R, and the viewing direction changing direction (vehicle width direction and vehicle up-down direction) is directed by the direction instruction unit 16S. Instruct.

  The rear side camera 12 obtains a rear side photographed image by photographing the rear side of the vehicle. The rear side photographed image obtained by photographing is output to the control device 18 as a photographing result of the rear side camera 12. The rear side camera 12 has an automatic exposure adjustment function that adjusts the exposure according to the brightness around the vehicle at the time of shooting, and adjusts to an appropriate exposure adjustment value according to the brightness around the vehicle. Do. The exposure adjustment is performed by a known technique, for example, by adjusting the shutter speed, the aperture, the sensitivity of the image sensor (exposure time), and the like based on the luminance distribution of each pixel of the captured image.

  The monitor 14 displays the rear side captured image captured by the rear side camera 12 in accordance with the control of the control device 18.

  The turn lamp switch 20 is a switch for instructing blinking for blinking the turn lamp. In this embodiment, the blinking instruction signal for the turn lamp switch 20 is input to the control device 18.

  Then, the control device 18 controls photographing by the rear side camera 12 and performs display control on the monitor 14 based on the photographing result of the rear side camera 12. Further, the control device 18 performs control to change the display position of the monitor 14 (rear side viewing range) when the operation unit 16 instructs to change the rear side viewing range. The display position of the monitor 14 is changed by, for example, displaying a partial image obtained by cutting out a part of the captured image on the monitor 14 and changing the cutout range to change the viewing range. Alternatively, the entire captured image may be displayed on the monitor 14, and the viewing range may be changed by changing the shooting direction of the rear side camera 12.

  In addition, the control apparatus 18 may perform display control of the left and right monitors 14 with one control apparatus 18, or a pair may be provided corresponding to the left and right of the vehicle. When a pair of control devices 18 are provided corresponding to the left and right, the other control device 18 may be connected to each I / O 18D so that they can communicate with each other.

  By the way, in the vehicular visual recognition device 10 configured as described above, when there is a light source that repeatedly blinks, such as a turn lamp, the brightness around the vehicle periodically changes by turning on and off the light source. When the brightness around the vehicle changes periodically, the exposure adjustment value by the automatic exposure adjustment function changes periodically according to the change in brightness. For example, as shown in FIG. 3A, the exposure adjustment value periodically changes as shown in FIG. 3B in accordance with the periodic change of the on / off state of the light source. At this time, since the exposure adjustment value changes after the on / off change of the light source, the image becomes overexposed or underexposed, and the brightness of the image changes, making it difficult to view the image. Specifically, as shown in FIGS. 3A and 3B, overexposure tends to occur between the time when the light source is turned on and the exposure adjustment value is adjusted, and the exposure adjustment is performed after the light source is turned off. It tends to be underexposed until the value is adjusted. For example, in the case where an image when no light blinks around the vehicle is as shown in FIG. 4 (A), when the image is overexposed, the entire image becomes white as shown in FIG. 4 (B). When underexposed, the entire image is crushed in black as shown in FIG.

  Therefore, in the present embodiment, when the control device 18 detects blinking of light around the vehicle and detects blinking, the exposure adjustment value when light is irradiated and the case where light is not irradiated The rear side camera 12 is controlled so as to maintain the exposure adjustment value between the exposure adjustment value and the exposure adjustment value. Thereby, since the exposure adjustment value is fixed, it is possible to improve the visibility by suppressing the fluctuation of the brightness of the photographed image even if the flashing of light occurs around the vehicle.

  Specifically, the control device 18 detects blinking of light by the turn lamp of the host vehicle by detecting a blinking instruction signal of the turn lamp switch 20. Alternatively, the control device 18 detects the periodic change of the exposure adjustment value of the automatic exposure adjustment function of the rear side camera 12, thereby causing the light to blink by another light source such as a turn lamp of a vehicle including another vehicle. It may be detected. Alternatively, an illuminance sensor may be further provided, and periodic light fluctuations around the vehicle may be detected from the detection result of the illuminance sensor.

  When the control device 18 detects blinking of light, as shown in FIG. 4C, the exposure adjustment value when light is irradiated and the exposure adjustment value when light is not irradiated. The rear side camera 12 is controlled so as to maintain the intermediate value. As shown in FIG. 4C, the intermediate value is described as the center value of the exposure amplitude in the present embodiment, but is not limited to the center value.

  In the present embodiment, the flashing of light detected by the control device 18 detects, for example, flashing that repeats turning on within 5 seconds and turning off within 5 seconds.

  Then, the specific process performed with the control apparatus 18 of the visual device 10 for vehicles which concerns on this embodiment comprised as mentioned above is demonstrated. FIG. 5 is a flowchart illustrating an example of a flow of processing performed by the control device 18 of the vehicle visual recognition device 10 according to the present embodiment. Note that the processing in FIG. 5 will be described as starting when an ignition switch (not shown) is turned on. 5 is performed when the CPU 18A develops and executes the visual image control program stored in the ROM 18B on the RAM 18C.

  First, in step 100, the CPU 18A controls the rear side camera 12 to start photographing with the rear side camera 12, and proceeds to step 102. Thereby, the rear side camera 12 performs exposure adjustment by the automatic exposure adjuster and starts photographing.

  In step 102, the CPU 18 </ b> A starts to sequentially acquire the captured images of the rear side camera 12 and proceeds to step 104.

  In step 104, the CPU 18 </ b> A controls the monitor 14 so that the acquired captured images are sequentially mirror-image converted and displayed on the monitor 14, and the process proceeds to step 106. Thereby, since the captured image of the vehicle rear side is displayed on the monitor 14 like an optical mirror, the vehicle rear side can be visually recognized as the periphery of the vehicle.

  In step 106, the CPU 18A determines whether or not periodic blinking of light has been detected. The determination is made, for example, by determining whether at least one of a blinking instruction signal of the turn lamp switch 20 and a periodic change in the exposure adjustment value of the automatic exposure adjustment function of the rear side camera 12 is detected. If the determination is negative, the process returns to step 104 and the above-described processing is repeated. If the determination is affirmative, the process proceeds to step 108. In the case where the illuminance sensor is provided, the blinking instruction signal of the turn lamp switch 20, the periodic change of the exposure adjustment value of the automatic exposure adjustment function, and the periodic fluctuation of light around the vehicle based on the detection result of the illuminance sensor. It may be determined whether at least one is detected.

  In step 108, the CPU 18A controls the rear side camera 12 to move to step 110 so that the exposure adjustment value of the rear side camera 12 is fixed to the intermediate value for shooting. That is, as shown in FIG. 3C, the rear side camera is maintained so as to maintain an intermediate value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated. Control 12 automatic exposure adjusters. As a result, the exposure adjustment value is fixed, so the exposure is adjusted according to the flashing of light and the screen does not switch, and even if the flashing of light occurs around the vehicle, fluctuations in the brightness of the captured image are suppressed. And visibility can be improved.

  In step 110, the CPU 18A determines whether or not the periodic light blinking has ended. In this determination, for example, it is determined whether or not the information for detecting the blinking of the light detected in Step 106 has been detected, and the process waits until the determination is affirmed and proceeds to Step 112.

  In step 112, the CPU 18A controls the rear side camera 12 so as to restore and shoot the automatic exposure adjuster of the rear side camera 12, and returns to step 104 to repeat the above processing.

  By performing the control in this manner, the exposure adjustment value at the time of shooting by the rear side camera 12 is fixed when the flashing of the light is detected. Therefore, even if the flashing of the light around the vehicle occurs, Visibility can be improved by suppressing variations in brightness.

  Next, a modified example of the vehicle visual recognition device according to the present embodiment will be described. FIG. 6 is a block diagram illustrating a configuration of a control system of the vehicular visual recognition device 11 according to a modification. In addition, about the same structure as said embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In the above embodiment, when flashing of light around the vehicle is detected, exposure is performed at an intermediate value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated. The adjustment value is maintained, but in the modified example, it is lower than the intermediate value in the case of darkness such as at night. By maintaining the exposure adjustment value lower in the dark case than in the bright case, it is possible to improve the visibility when there is flashing of the light in the dark such as at night.

  In the modification, as shown in FIG. 6, a light switch 22 and an illuminance sensor 24 are further connected to the I / O 18 </ b> D with respect to the above embodiment. That is, a lighting instruction signal of at least one of the headlamp and the vehicle width lamp by the light switch 22 and the detection result of the illuminance sensor 24 are input to the control device 18.

  The control device 18 detects whether or not the surroundings of the vehicle is in a predetermined dark environment such as nighttime based on the lighting instruction signal of the light switch 22 and the detection result of the illuminance sensor 24. In addition, although demonstrated as a structure provided with both the light switch 22 and the illumination intensity sensor 24 in a modification, it is good also as a form provided only with either one.

  Then, the specific process performed with the control apparatus 18 of the visual recognition apparatus 11 for vehicles of a modification is demonstrated. FIG. 7 is a flowchart illustrating an example of a flow of processing performed by the control device 18 of the vehicle visual recognition device 11 according to the modification. Note that the processing of FIG. 7 will be described as starting when an ignition switch (not shown) is turned on. 7 is performed when the CPU 18A develops and executes the visual image control program stored in the ROM 18B on the RAM 18C. Further, the same processing as in the above embodiment will be described with the same reference numerals.

  First, in step 100, the CPU 18A controls the rear side camera 12 to start photographing with the rear side camera 12, and proceeds to step 102. Thereby, the rear side camera 12 performs exposure adjustment by the automatic exposure adjuster and starts photographing.

  In step 102, the CPU 18 </ b> A starts to sequentially acquire the captured images of the rear side camera 12 and proceeds to step 104.

  In step 104, the CPU 18 </ b> A controls the monitor 14 so that the acquired captured images are sequentially mirror-image converted and displayed on the monitor 14, and the process proceeds to step 106. Thereby, since the captured image of the vehicle rear side is displayed on the monitor 14 like an optical mirror, the vehicle rear side can be visually recognized as the periphery of the vehicle.

  In step 106, the CPU 18A determines whether or not periodic blinking of light has been detected. The determination is made, for example, by a blinking instruction signal of the turn lamp switch 20, a periodic change in the exposure adjustment value of the automatic exposure adjustment function of the rear side camera 12, and a periodic light around the vehicle based on the detection result of the illuminance sensor. It is determined whether at least one of the fluctuations is detected. If the determination is negative, the process returns to step 104 and the above-described processing is repeated. If the determination is affirmative, the routine proceeds to step 107.

  In step 107, the CPU 18A determines whether or not the environment is dark such as at night. The determination is made, for example, by determining whether at least one of a lighting instruction signal of the light switch 22 and a detection signal of the illuminance sensor 24 representing illuminance equal to or lower than a predetermined illuminance is detected. If the determination is negative, the process proceeds to step 108, and if the determination is affirmative, the process proceeds to step 109.

  In step 108, the CPU 18A controls the rear side camera 12 to move to step 110 so that the exposure adjustment value of the rear side camera 12 is fixed to the intermediate value for shooting. That is, as shown in FIG. 3C, the rear side camera is maintained so as to maintain an intermediate value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated. Control 12 automatic exposure adjusters. As a result, the exposure adjustment value is fixed, so the exposure is adjusted according to the flashing of light and the screen does not switch, and even if the flashing of light occurs around the vehicle, fluctuations in the brightness of the captured image are suppressed. And visibility can be improved.

  On the other hand, in step 109, the CPU 18A controls the rear side camera 12 so that the exposure adjustment value of the rear side camera 12 is fixed to an exposure adjustment value smaller than the intermediate value, and proceeds to step 110. . That is, the rear side camera 12 is automatically operated so as to maintain an exposure adjustment value smaller than an intermediate value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated. Control the exposure adjuster. As a result, the exposure adjustment value is fixed to a value smaller than the intermediate value, so that the exposure is adjusted according to the flashing of the light and the screen does not switch. Visibility can be improved by suppressing fluctuations in height. Further, in a dark environment such as at night, the exposure adjustment value is fixed to a value smaller than the intermediate value. Therefore, it is possible to improve the visibility when there is blinking of light when it is dark such as at night.

  In step 110, the CPU 18A determines whether or not the periodic light blinking has ended. In this determination, for example, it is determined whether or not the information for detecting the blinking of the light detected in Step 106 has been detected, and the process waits until the determination is affirmed and proceeds to Step 112.

  In step 112, the CPU 18A controls the rear side camera 12 so as to restore and shoot the automatic exposure adjuster of the rear side camera 12, and returns to step 104 to repeat the above processing.

  By performing the control in this manner, the exposure adjustment value at the time of shooting by the rear side camera 12 is fixed when the flashing of the light is detected, as in the above embodiment, so that the flashing of the light around the vehicle Even if this occurs, it is possible to improve the visibility by suppressing fluctuations in the brightness of the captured image. Further, in a dark environment such as at night, the exposure adjustment value is fixed to a value smaller than the intermediate value. Therefore, it is possible to improve the visibility when there is blinking of light when it is dark such as at night.

  In the above-described embodiment and modification, the vehicle visual recognition device that captures and visually recognizes the rear side of the vehicle as the vehicle periphery has been described as an example, but the present invention is not limited thereto. For example, you may apply the visual device for vehicles which image | photographs and displays other directions, such as a vehicle side and the front, back.

  Moreover, although the process performed by the control apparatus 18 in said embodiment and modification was demonstrated as a software process, it is not restricted to this. For example, the processing may be performed by hardware, or may be processing that combines both hardware and software.

  Further, the processing performed by the control device 18 in the above-described embodiments and modifications may be stored and distributed as a program in a storage medium.

  Furthermore, the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10, 11 Vehicle visual recognition device 12 Rear side camera 14 Monitor 18 Control device 20 Turn lamp switch 22 Light switch 24 Illuminance sensor

Claims (4)

A shooting unit that adjusts the exposure according to the brightness around the vehicle and shoots around the vehicle;
A display unit for displaying a photographed image photographed by the photographing unit;
A detection unit that detects blinking of light around the vehicle;
When the flashing of the light is detected by the detection unit, the exposure adjustment value between the exposure adjustment value when the light is irradiated and the exposure adjustment value when the light is not irradiated is maintained. A control unit for controlling the imaging unit;
A vehicular visual recognition device.   The vehicular visual recognition device according to claim 1, wherein the detection unit detects blinking of light by detecting a turn lamp blinking instruction signal.   The vehicular visual recognition device according to claim 1, wherein the detection unit detects blinking of light by detecting light around the vehicle or a periodic change in an exposure adjustment value at the time of photographing by the photographing unit.   The control unit detects a predetermined dark environment, and when the dark environment is detected, the photographing unit maintains an exposure adjustment value smaller than an exposure adjustment value maintained when the dark environment is not detected. The visual device for vehicles according to any one of claims 1 to 3, further controlling the unit.