JP2016030507A - On-vehicle display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle display device capable of preventing degradation in visibility due to disagreement of focal point, so that a burden on an eye of a driver because of abrupt focal point adjustment is reduced.SOLUTION: A congestion detection part 504 detects shifting of a line of sight of a driver from a front of a vehicle to a display device 5, and detects change amount of a congestion angle when the driver shifts its line of sight from the front of the vehicle to the display device 5. A control part 505, based on the change amount of the congestion angle that is detected with the congestion detection part 504, switches display of the display device 5 by turning ON or OFF a liquid crystal display 501.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an in-vehicle display device that presents an image captured by a camera mounted on a vehicle to a driver.

  As a conventional in-vehicle display device, an electronic mirror device in which a half mirror is provided in front of a video display unit is known. When the rear view is obstructed by the rear seat display or the like and it becomes difficult to monitor the rear using a half mirror, the driver displays an image of the rear of the vehicle taken by the camera from the display of the half mirror. A device that switches to display on a video display unit and performs rear monitoring is known (see, for example, Patent Document 1).

  However, in the conventional electronic mirror device, the driver may forget which display the display of the electronic mirror device is switched to.

  Usually, the driver adjusts the focus so that he can see far away. If the driver forgets to switch the display of the electronic mirror device to the display by the video display unit and looks at the electronic mirror device through the half mirror to see the rear of the vehicle, the visibility of the electronic mirror device due to the mismatch of the focus Decrease.

  In order to visually recognize the display of the electronic mirror device, the driver re-adjusts the focus, which has been adjusted to visually recognize far away, in order to visually recognize the near video display unit. Rapid focus adjustment is a burden on the driver's eyes.

JP 11-291817 A

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide an in-vehicle display device that prevents a drop in visibility due to a mismatch in focus and reduces a driver's eye burden due to a rapid focus adjustment. .

  In order to solve the above problem, an in-vehicle display device of the present invention is an in-vehicle display device that presents an image captured by a camera mounted on a vehicle to a driver, the display for displaying an image, and the display A control unit for controlling, and a congestion detection unit for detecting a change in congestion of the driver when the driver moves his / her line of sight to the display unit, the control unit based on a detection result of the congestion detection unit The display is switched.

  According to the present invention, the control unit switches the display of the display based on the detection result of the congestion detection unit, thereby preventing a decrease in visibility due to a focus mismatch and reducing a driver's eye burden due to a rapid focus adjustment. An in-vehicle display device can be provided.

The front view which shows the vehicle interior of the vehicle carrying the vehicle-mounted display apparatus in Embodiment 1 of this invention. Same as above, top view of the vehicle Cross section of the vehicle The front view of the indicator in Embodiment 1 of the present invention Sectional drawing of the indicator in Embodiment 1 of this invention Control block diagram of in-vehicle display device in Embodiment 1 of the present invention The figure explaining an example of the convergence exercise | movement at the time of the driver in Embodiment 1 of this invention moving a line of sight from a vehicle front to a display device The flowchart which shows an example of operation | movement of the vehicle-mounted display apparatus in Embodiment 1 of this invention. The front view which shows the vehicle interior of the vehicle carrying the vehicle-mounted display apparatus in Embodiment 2 of this invention. Cross section of the vehicle Control block diagram of in-vehicle display device in Embodiment 2 of the present invention The figure explaining an example of the convergence movement at the time of the driver in Embodiment 2 of this invention moving a line of sight from a vehicle front to a half mirror The flowchart which shows an example of operation | movement of the vehicle-mounted display apparatus in Embodiment 2 of this invention.

Hereinafter, an example in which an in-vehicle display device according to an embodiment of the present invention is mounted on a vehicle will be described with reference to the accompanying drawings.
(Embodiment 1)
As shown in FIGS. 1 to 3, the vehicle 1 includes a display 5 that constitutes an in-vehicle display device at a mounting position of a rearview mirror at a front portion between a driver seat 3 and a passenger seat 4 in a passenger compartment 2. However, it is attached to the attachment portion 7 so as to be movable and adjustable.

  A driver monitor camera 6 that captures the driving situation of the driver is installed on the upper part of the steering column cover.

  As shown in FIG. 4, the image 50 displayed on the display 5 can be switched between a display using a liquid crystal display as a video display unit and a display using a half mirror by operating the operation unit 503.

  As shown in FIG. 5, the display 5 includes a main body case 5A having an opening on the driver's seat side, a liquid crystal display 501 mounted on the main body case 5A so that the liquid crystal display surface is on the driver's seat side, The configuration includes a half mirror 502 provided on the driver's seat side 501 and an operation unit 503 for turning the liquid crystal display 501 on and off.

  The liquid crystal display 501 is connected to the control unit 505 as shown in FIG. The control unit 505 is connected to the operation unit 503, the congestion detection unit 504, and the rear camera 8.

  The control unit 505 and the congestion detection unit 504 include a CPU that controls operations, a ROM that stores a control program, and a RAM that stores temporarily held data and control data.

  The congestion detection unit 504 is connected to the driver monitor camera 6. The congestion detection unit 504 detects the movement of the line of sight to the display 5 of the driver shown in FIG. 7 and the movement of the driver during the movement of the line of sight from the driver image captured by the driver monitor camera 6.

  The vergence movement refers to an eye movement in which the left and right eyes rotate in different directions for gazing at an object moving in the front-rear direction, and the angle formed by the lines of sight of the left and right eyes is referred to as the convergence angle.

  FIG. 7 shows an example of the convergence movement when the driver moves his / her line of sight from the front of the vehicle to the display 5.

  FIG. 7A shows the convergence movement when the driver moves the line of sight from the front of the vehicle to the rear of the vehicle through the half mirror 502 of the display 5. The driver intends to directly view the rear of the vehicle with the half mirror 502. When looking at the rear of the vehicle through the half mirror 502, the amount of change in the convergence angle during movement of the line of sight is small.

  FIG. 7B shows the convergence motion when the driver moves his / her line of sight from the front of the vehicle to the liquid crystal display 501 of the display 5. The driver intends to visually recognize the rear of the vehicle through an image displayed on the liquid crystal display 501. When viewing the display screen of the liquid crystal display 501, the amount of change in the convergence angle during movement of the line of sight is larger than that in FIG.

  When detecting the movement of the driver's line of sight from the front of the vehicle to the display 5, the congestion detection unit 504 detects the convergence movement during the movement of the line of sight and calculates the amount of change in the convergence angle.

  The congestion detection unit 504 determines whether or not the detected change amount of the convergence angle due to the convergence motion is equal to or greater than a predetermined threshold value, and outputs the determination result to the control unit 505.

  In other words, the congestion detection unit 504 detects the movement of the driver's line of sight from the front of the vehicle to the display 5, and the movement of the driver's line of sight to the display 5 moves to the half mirror 502 based on the amount of change in the convergence angle ( It is determined whether the detected change amount of the convergence angle is less than a predetermined threshold value) or the line of sight movement to the liquid crystal display 501 (the detected change amount of the convergence angle is equal to or greater than the predetermined threshold value), and the determination result is output to the control unit 505.

  The in-vehicle display device 500 according to the first embodiment is provided with a training mode for accurately detecting the movement of the line of sight in the congestion detection unit 504 and performing the above determination.

  In the training mode, the control unit 505 switches the display on the display 5 between the display on the liquid crystal display 501 and the display on the half mirror 502, and the driver moves the line of sight from the front of the vehicle to the liquid crystal display 501 by a speaker (not shown). An instruction to move the line of sight from the front of the vehicle to the rear of the vehicle through the half mirror 502 is given.

  The congestion detection unit 504 acquires and stores face image data of the driver when the driver moves his / her line of sight from the front of the vehicle to the display 5 in the training mode. The congestion detection unit 504 detects the movement of the driver's line of sight from the front of the vehicle to the display 5 based on the driver's face image data acquired in the training mode.

  The convergence detection unit 504 is the amount of change in the convergence angle when moving the line of sight from the front of the vehicle to the liquid crystal display 501 acquired in the training mode, and the convergence angle when moving the line of sight from the front of the vehicle to the rear of the vehicle through the half mirror 502. From the amount of change, a threshold value for determining whether the driver's line of sight movement to the display 5 is the line of sight movement behind the liquid crystal display 501 or the half mirror 502 is determined and stored.

  The control unit 505 switches the display on the display 5 between the display by the liquid crystal display 501 and the display by the half mirror 502 based on the input from the congestion detection unit 504.

  An example of main operations in the first embodiment of the vehicle-mounted display device 500 in the first embodiment of the present invention configured as described above will be described.

  FIG. 8 is a flowchart showing an example of main operations related to the first embodiment of the in-vehicle display device 500.

  When the processing is started, the congestion detection unit 504 starts detecting the movement of the line of sight from the front of the driver's vehicle to the display 5 from the camera image of the driver monitor camera 6.

  When detecting the movement of the driver's line of sight from the front of the vehicle to the display 5 (step S801, YES), the congestion detection unit 504 detects the movement of the driver's line of sight and calculates the amount of change in the convergence angle. (Step S802). The congestion detection unit 504 compares the calculated amount of change in the convergence angle with a threshold value, and outputs a result (“more than threshold value” or “less than threshold value”) to the control unit 505 (step S803).

  If the congestion detection unit 504 does not detect the movement of the driver's line of sight from the front of the vehicle to the display 5 (NO in step S801), the congestion detection unit 504 repeats the detection of the movement of the driver's visual line from the front of the vehicle to the display 5.

  When the input from the congestion detection unit 504 is equal to or greater than the threshold (step S804, YES), the control unit 505 determines whether or not the current display on the display 5 is a display by the liquid crystal display 501, that is, the liquid crystal display 501 is ON. It is determined whether or not it is in a state (step S805). If the liquid crystal display 501 is in the ON state (step S805, YES), the process ends.

  When the liquid crystal display 501 is not in the ON state (step S805, NO), that is, when the display 5 is a display by the half mirror 502, the control unit 505 turns the liquid crystal display 501 on (step S806), and the display 5 Is switched from the display by the half mirror 502 to the display by the liquid crystal display 501, and the processing is terminated.

  When the input from the congestion detection unit 504 is less than the threshold value (NO in step S804), the control unit 505 determines whether or not the current display on the display 5 is a display by the half mirror 502, that is, the liquid crystal display 501 is turned off. It is determined whether it is in a state (step S807). If the liquid crystal display 501 is in the OFF state (step S807, YES), the process is terminated.

  When the liquid crystal display 501 is not in the OFF state (step S807, NO), that is, when the display 5 is a display by the liquid crystal display 501, the control unit 505 sets the liquid crystal display 501 in the OFF state (step S808). Is switched from the display on the liquid crystal display 501 to the display on the half mirror 502, and the process ends.

  As described above, according to the vehicle-mounted display device 500 according to the first embodiment of the present invention, the control unit 505 switches the display of the display unit 5 based on the detection result of the congestion detection unit 504, so Can be provided, and the on-vehicle display device can be provided in which the burden on the eyes of the driver due to rapid focus adjustment is reduced.

  Further, by providing the training mode, it is possible to switch the display of the display using a threshold value suitable for each driver.

  In the first embodiment, the congestion detection unit 504 is described as dedicated hardware. However, a program for realizing the function is configured as a program that can be read by the control unit 505, and is executed by the CPU of the control unit 505. You may comprise as follows.

In the first embodiment, the case where the driver switches the display on the display 5 based on the amount of change in the convergence angle when the driver moves his / her line of sight from the front of the vehicle to the display 5 in the passenger compartment is described. Other than that, for example, when the line of sight is moved from the speedometer in the passenger compartment to the indicator 5 in the passenger compartment, the display of the indicator 5 can be similarly switched based on the amount of change in the convergence angle.

(Embodiment 2)
Hereinafter, the in-vehicle display device according to Embodiment 2 of the present invention will be described. The difference from the first embodiment is that the display in the second embodiment displays an image captured by the camera as a virtual image while changing the display distance.

  Usually, an image obtained by capturing a distant object is displayed as a virtual image in the distance, and an image obtained by capturing a distant object is displayed in the vicinity as a virtual image. In the second embodiment, when a virtual image of a near image is viewed with the intention of visually recognizing a virtual image of a distant image, or a distant image is captured with a view of a virtual image of a near image. An object of the present invention is to provide an in-vehicle display device that prevents a drop in visibility due to a mismatch in focus that occurs when a virtual image of an image is visually recognized, and that reduces the burden on the driver's eyes due to rapid focus adjustment.

  Hereinafter, an in-vehicle display device according to a second embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the detailed description is abbreviate | omitted.

  As shown in FIG. 9 and FIG. 10, the vehicle 1 includes a display of the in-vehicle display device at the mounting position of the rearview mirror in the front portion between the driver's seat 3 and the passenger seat 4 in the passenger compartment 2. The half mirror 9 </ b> A that constitutes is attached by the attachment portion 7.

  The display device according to the second embodiment includes a liquid crystal display 9C that displays a camera image, a display distance changing unit 9B that changes a display distance of a virtual image of the camera image displayed by the liquid crystal display 9C, and a display distance of the virtual image by a display distance changing unit 9B. Is composed of a half mirror 9A that reflects the changed camera image.

  The display distance changing unit 9B includes, for example, a plurality of lenses having different focal lengths and a driving unit that sets the lenses on the front surface of the liquid crystal display 9C.

  In Embodiment 2, the display distance changing unit 9B has a second display distance longer than the first display distance by the first lens and the first display distance by the second lens having a shorter focal distance than the first lens. It is the composition which changes.

  As shown in FIG. 10, the liquid crystal display 9C and the display distance changing unit 9B display a camera image displayed on the liquid crystal display 9C whose virtual image display distance has been changed by the display distance changing unit 9B on the upper part of the vehicle interior 2. Is arranged in a positional relationship that is reflected by the driver and visually recognized by the driver.

  The liquid crystal display 9 </ b> C is configured so that the camera image of the mirror camera 10 that captures the interior 2 of the vehicle installed in the upper part of the half mirror 9 </ b> A of the attachment 7 and the rear camera 8 installed in the rear of the interior 2 are farther away than the mirror camera 10. The camera image to be photographed is switched and displayed.

  The liquid crystal display 9C and the display distance changing unit 9B constituting the display device 901 are connected to the control unit 905 as shown in FIG. The control unit 905 is connected to the liquid crystal display 9C, the operation unit 903 for operating the display distance changing unit 9B, the congestion detection unit 904, the rear camera 8, and the mirror camera 10.

  The control unit 905 and the congestion detection unit 904 include a CPU that controls operations, a ROM that stores a control program, and a RAM that stores temporarily held data and control data.

  The congestion detection unit 904 is connected to the driver monitor camera 6. The congestion detection unit 904 detects the movement of the line of sight to the virtual image via the driver's half mirror 9A shown in FIG. 12 and the driver's convergence movement during the movement of the line of sight from the driver image captured by the driver monitor camera 6.

  The driver visually recognizes the virtual image of the camera image displayed on the liquid crystal display 9C at the display distance changed by the display distance changing unit 9B via the half mirror 9A.

  FIG. 12 shows an example of the convergence motion when the driver moves his / her line of sight from the front of the vehicle to the virtual image via the half mirror 9A.

  FIG. 12A shows the convergence motion when the driver moves his / her line of sight from the front of the vehicle to a virtual image with a long display distance. The amount of change in the convergence angle during movement of the line of sight from the front of the vehicle to the virtual image is small.

  FIG. 12B shows the convergence motion when the driver moves his / her line of sight from the front of the vehicle to a virtual image with a short display distance. Compared to FIG. 12A, the amount of change in the convergence angle during the movement of the line of sight from the front of the vehicle to the virtual image is larger.

  When detecting the line of sight movement from the front of the driver to the virtual image via the half mirror 9A, the congestion detection unit 904 detects the convergence movement during the movement of the line of sight and calculates the amount of change in the convergence angle.

  The congestion detection unit 904 determines whether or not the change amount of the convergence angle due to the detected convergence motion is equal to or greater than a predetermined threshold value, and outputs the determination result to the control unit 905.

  In other words, the convergence detection unit 904 detects the movement of the driver's line of sight from the front of the vehicle via the half mirror 9A, and changes the convergence angle from the front of the driver to the virtual image via the half mirror 9A based on the amount of change in the convergence angle. Eye movement to a virtual image with a long display distance (change in the detected convergence angle is less than a predetermined threshold) or eye movement to a virtual image with a short display distance (the change in the detected convergence angle is greater than or equal to a predetermined threshold) And the determination result is output to the control unit 905.

  Similar to the first embodiment, the in-vehicle display device 900 according to the second embodiment is also provided with a training mode for accurately detecting the movement of the line of sight in the congestion detection unit 504 and performing the above determination.

  In the training mode, the control unit 905 switches the display of the display 901 between a virtual image with a long display distance and a virtual image with a short display distance, and a driver (not shown) looks at the driver from the front of the vehicle to the virtual image with a long display distance. Instructs movement and line of sight movement to a virtual image with a short display distance

  The congestion detection unit 904 acquires and stores face image data of the driver when the driver moves his / her line of sight from the front of the vehicle to the virtual image via the half mirror 9A in the training mode. The congestion detection unit 904 detects the movement of the driver's line of sight from the front of the vehicle to the half mirror based on the driver's face image data acquired in the training mode.

The convergence detection unit 904 determines the amount of change in the convergence angle when moving the line of sight from the front of the vehicle acquired in the training mode to the virtual image with a long display distance via the half mirror 9A and the display distance via the half mirror 9A from the front of the vehicle. From the amount of change in the convergence angle when moving the line of sight to a short virtual image, the movement of the line of sight of the driver to the half mirror 9A changes from the line of sight to a virtual image with a long display distance or a virtual image with a short display distance. A threshold for determining whether the line of sight is moving is determined and stored.

  The control unit 905 switches between the camera image displayed on the liquid crystal display 9C and the display distance of the virtual image by the display distance changing unit 9B based on the input from the congestion detection unit 904.

  An example of main operations in the second embodiment of the vehicle-mounted display device 900 in the second embodiment of the present invention configured as described above will be described.

  FIG. 13 is a flowchart showing an example of main operations relating to the second embodiment of the in-vehicle display device 900.

  When the processing is started, the congestion detection unit 904 starts detecting the movement of the line of sight from the front of the driver to the half mirror 9A from the camera image of the driver monitor camera 6.

  When detecting the driver's line-of-sight movement from the front of the vehicle to the half mirror 9A (step S1301, YES), the congestion detection unit 904 detects the movement of the driver's line-of-sight and calculates the amount of change in the convergence angle. (Step S1302). The congestion detection unit 504 compares the calculated change amount of the convergence angle with a threshold value, and outputs a result (“more than threshold value” or “less than threshold value”) to the control unit 905 (step S1303).

  If the congestion detection unit 904 does not detect the movement of the driver's line of sight from the front of the vehicle to the half mirror 9A (NO in step S1301), the congestion detection unit 904 repeats the detection of the movement of the driver's line of sight from the front of the vehicle to the half mirror 9A.

  When the input from the congestion detection unit 904 is greater than or equal to the threshold (YES in step S1304), the control unit 905 displays the camera image of the mirror camera 10 and displays the second display distance on the liquid crystal display 9C. It is determined whether or not the first display distance is shorter than the distance (step S1305).

  When the control unit 905 determines that the display on the liquid crystal display 9C is the display of the camera image of the mirror camera 10 and the display distance is the first display distance shorter than the second display distance (YES in step S1305). Exit.

  When the control unit 905 determines that the display on the liquid crystal display 9C is not the display of the camera image of the mirror camera 10 and the display distance is not the first display distance shorter than the second display distance (NO in step S1305). 905 switches the display on the liquid crystal display 9C to the camera image of the mirror camera 10 (step S1306), and the control unit 905 displays the display distance changing unit so that the display distance becomes the first display distance shorter than the second display distance. The 9B lens is switched to the first lens (step S1307), and the process ends.

  When the input from the congestion detection unit 904 is less than the threshold (NO in step S1304), the control unit 905 displays the camera image of the rear camera 8 and the display distance is the first display. It is determined whether or not the second display distance is longer than the distance (step S1308).

  When the control unit 905 determines that the display on the liquid crystal display 9C is the display of the camera image of the rear camera 8, and the display distance is the second display distance longer than the first display distance (YES in step S1308). Exit.

  When the control unit 905 determines that the display on the liquid crystal display 9C is not the display of the camera image of the rear camera 8 and that the display distance is not the second display distance longer than the first display distance (NO in step S1308). 905 switches the display on the liquid crystal display 9C to the camera image of the rear camera 8 (step S1309), and the control unit 905 displays the display distance changing unit so that the display distance becomes a second display distance longer than the first display distance. The 9B lens is switched to the second lens (step S1310), and the process ends.

  As described above, according to the vehicle-mounted display device 900 according to Embodiment 2 of the present invention, the display distance at which the control unit 905 displays the image displayed by the display 901 and the virtual image of the image based on the detection result of the congestion detection unit 904. By switching between the two, it is possible to provide a vehicle-mounted display device that prevents a drop in visibility due to a mismatch in focus and reduces the burden on the driver's eyes due to rapid focus adjustment.

  In the second embodiment, the camera image displayed on the liquid crystal display 9C and the virtual image display distance are switched based on the input from the congestion detection unit 904. However, the camera image is not switched and only the virtual image display distance is switched. It is good.

  By switching only the virtual image display distance based on the amount of change in convergence, it is possible to prevent a drop in visibility due to a mismatch in focus, and to reduce the burden on the driver's eyes due to rapid focus adjustment.

  Further, the present invention is not limited to the configuration of the display, and any configuration may be used as long as the display displays a virtual image of an image captured by the camera while changing the display distance of the virtual image.

  In the second embodiment, the congestion detection unit 904 is described as dedicated hardware. However, a program for realizing the function is configured as a program that can be read by the control unit 905, and is executed by the CPU of the control unit 905. You may comprise as follows.

  In the second embodiment, the case where the display is switched on the basis of the amount of change in the convergence angle when the driver moves the line of sight from the front of the vehicle to the display in the vehicle interior is described. For example, when the line of sight is moved from the speedometer in the passenger compartment to the indicator in the passenger compartment, the display can be switched based on the amount of change in the convergence angle.

  The vehicle-mounted display device of the present invention is useful as a vehicle-mounted monitoring device such as an electronic mirror.

DESCRIPTION OF SYMBOLS 1 Vehicle 5 Display 6 Driver monitor camera 7 Mounting part 8 Rear camera 9A Half mirror 9B Display distance change part 9C Liquid crystal display 10 Mirror camera 5A Main body case 500 In-vehicle display device 501 Liquid crystal display 502 Half mirror 503 Operation part 504 Congestion detection part 505 Control unit 900 In-vehicle display device 901 Display unit 903 Operation unit 904 Congestion detection unit 905 Control unit

Claims (7)

A vehicle-mounted display device that presents an image captured by a camera mounted on a vehicle to a driver,
A display for displaying images;
A control unit for controlling the display;
A congestion detection unit that detects a change amount of the convergence angle of the driver when the driver moves the line of sight to the display;
The said control part is a vehicle-mounted display apparatus which switches the display of the said indicator based on the detection result of the said congestion detection part. The display includes a main body case having an opening on a driver's seat side installed at a mounting position of a rearview mirror in a vehicle interior, an image display unit attached to the opening of the main body case, and the image display unit. With a half mirror arranged on the driver's seat side,
The on-vehicle display device according to claim 1, wherein the control unit switches the display of the display device between display by the image display unit and display by the half mirror based on a detection result of the congestion detection unit.   The control unit displays the display on the display when the detection result of the congestion detection unit is greater than or equal to a predetermined threshold, and displays the display when the detection result of the congestion detection unit is less than the threshold. The in-vehicle display device according to claim 2, wherein display of the display is switched to display by the half mirror. The display is a display that displays a virtual image of an image captured by a camera by changing a display distance of the virtual image,
The control unit is configured to display the display on the display unit by displaying the virtual image of the first image at the first display distance and the virtual image of the second image at the first display distance based on the detection result of the congestion detection unit. The in-vehicle display device according to claim 1, wherein the display is switched to a display that is displayed at a longer second display distance.   When the detection result of the congestion detection unit is equal to or greater than a predetermined threshold, the control unit displays the display on the display unit to display a virtual image of the first image at the first display distance. The in-vehicle display device according to claim 4, wherein when the result is less than the threshold, the display on the display is switched to a display that displays a virtual image of the second image at a second display distance longer than the first display distance.   The in-vehicle display device according to any one of claims 4 to 5, wherein the second image is configured as an image obtained by photographing a distance from the first image.   The in-vehicle display device according to any one of claims 4 to 6, wherein the first image is an image obtained by photographing the vehicle interior, and the second image is an image obtained by photographing the rear of the vehicle.