JP2007323001A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of reproducing the way in which an image displayed behind a user is actually viewed when the user views the image through reflection by a mirror. <P>SOLUTION: When it is judged that a driver looks in a rear-view mirror 17, an image obtained when the visual point is placed on a reflecting surface of the rear-view mirror 17 is projected on an area 14A on a screen 14 reflected in the rear-view mirror 17. When it is judged that the driver looks in a left or right door mirror 18 or 19, an image obtained when the view point is placed on a reflecting surface of the left door mirror 18 is projected on an area 14E on the screen reflected in the left door mirror 18, and an image obtained when the visual point is placed on the reflecting surface of the right door mirror 19 is projected on an area 14F on the screen 14 reflected in the right door mirror 19. When it is judged that the driver looks back directly, an image obtained when the visual point is placed at the eyeball position of the driver is projected on the screen 14 behind a vehicle model 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display device.

  Simulated driving is performed by synchronously displaying live-action traveling images acquired in advance on the screens provided on the front, left, right, and rear, and by changing the displayed actual traveling images according to the driving operation of the driver (subject). A driving simulator that realizes traveling is described in Patent Document 1 below.

The live-action running video used in this driving simulator is acquired as follows. That is, first, a running image is recorded by a recording vehicle equipped with a video camera in four directions, front, rear, left and right. Next, the recorded traveling video is edited so as to be a video with a viewpoint on the driver, that is, a video viewed from the driver, and a video projected on each screen is acquired.
JP 2005-3923 A

  The driving simulator includes a rear view mirror (rear mirror) and left and right side mirrors for confirming the rear in order to further improve the consistency with the actual vehicle. Therefore, the driver can confirm the rear side by reflecting the image of the rear screen on these rearview mirrors and side mirrors, as in actual vehicle driving.

  However, since the video displayed on the rear screen is the video seen from the driver as described above, when looking at the rear through the rear view mirror and the left and right door mirrors, It looks different. Thus, the display device applied to the driving simulator cannot reproduce the same appearance as an actual vehicle when looking backward through the mirror.

  The present invention has been made to solve the above problems, and reproduces the same appearance as when the user sees the image displayed behind the user by reflecting it on a mirror. An object of the present invention is to provide an image display device capable of performing the above.

  An image display device according to the present invention detects display means for displaying an image on a display surface provided around a user, a rear viewing mirror for the user to visually observe the back, and a user's gaze direction. Line-of-sight detection means, and when the display means determines that the user is looking through the rear viewing mirror based on the line-of-sight direction of the user detected by the line-of-sight detection means, An image created by placing the viewpoint on the reflection surface of the rear viewing mirror is displayed in the area of the display surface reflected on the viewing mirror.

  According to the image display device according to the present invention, when it is determined from the detected user's line-of-sight direction that the user is looking through the rear viewing mirror, the display surface reflected on the rear viewing mirror is displayed. An image created by placing the viewpoint on the reflection surface of the rear viewing mirror is displayed in the area. Therefore, when the user sees the image displayed behind by reflecting the image to the rear viewing mirror, the same appearance as in reality can be reproduced.

  Here, as the display means, it is preferable to use a projector that projects an image on a screen.

  Further, the image display device according to the present invention includes a plurality of rear viewing mirrors, and the display means allows the user to be behind the rear viewing mirror based on the detected direction of the user's line of sight. When it is determined that the user is looking, an image created with the viewpoint on the reflective surface of the rear viewing mirror that the user is viewing is displayed in the area of the display surface that is reflected on the rear viewing mirror that the user is viewing. It is preferable to do.

  When a plurality of rear viewing mirrors are provided in this way, the rear viewing mirror that the user is looking at is identified from the detected user's line-of-sight direction, and the rear viewing mirror is displayed in the area of the display surface reflected on the rear viewing mirror. An image created by placing the viewpoint on the reflection surface is displayed. Therefore, even when a plurality of rear viewing mirrors are provided, it is possible to reproduce the same appearance as reality for all rear viewing mirrors.

  The display means displays an image created with the viewpoint at the position of the user's eyeball when it is determined that the user is directly looking backward based on the detected line-of-sight direction of the user. It is preferable.

  Compared with the case of looking at the back through the rear viewing mirror, when looking back, the direction of the face and the direction of the line of sight move greatly, so that the detection can be easily performed. In general, looking back requires more time than moving only the line of sight. Therefore, when it is determined that the user is looking back and looking directly behind, the image created by placing the viewpoint at the user's eyeball position is displayed, so that switching of images can be performed more appropriately. Can be done.

  According to the present invention, when it is determined from the detected direction of the user's line of sight that the user is looking behind through the rear viewing mirror, the area of the display surface reflected on the rear viewing mirror is Since the image created with the viewpoint on the reflecting surface of the mirror is displayed, it is possible to reproduce the same appearance as in reality when the image displayed behind the user is reflected on the mirror. It becomes possible.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts.

  As a first embodiment, an example will be described in which the image display device according to the present invention is applied to a driving simulator that simulates the motion of a vehicle in accordance with a driving operation of a driver (user).

  First, the configuration of a driving simulator 10 to which the image display device 1 according to the first embodiment is applied will be described with reference to FIGS. 1 and 2 together. FIG. 1 is a diagram showing a main configuration of the driving simulator 10. FIG. 2 is a block diagram showing a configuration of the image display device 1 applied to the driving simulator 10.

  The driving simulator 10 is a driving simulation device for analyzing and investigating the behavior of the vehicle driver and the vehicle behavior under various conditions. The driving simulator 10 is a visual field simulation unit that simulates the visual field outside the vehicle that changes as the vehicle travels. Is composed of a motion simulation section for giving to the vehicle and a control feeling simulation section for giving an operation reaction force and the like. Here, the image display apparatus 1 is applied to a visual field simulation unit. More specifically, the driving simulator 10 includes a dome 12 in which the vehicle model 11 is installed. The driving simulator 10 calculates the operation state of the operation system and the movement state of the vehicle model 11 based on the driving operation of the driver. The vehicle travels by driving an actuator, an dome 12 or the like that applies an operational reaction force according to the calculation result, and projecting a simulation image such as a travel scene onto the cylindrical screen 14 provided on the inner peripheral surface of the dome 12. To simulate.

  The dome 12 has a substantially cylindrical shape, and a circular base 13 is rotatably installed on the bottom surface thereof. The vehicle model 11 is installed on the upper surface of the base 13 via a support portion. Further, a rotation position sensor 15 for detecting a rotation position of the base 13 (that is, the vehicle model 11) is attached to the base 13. The rotation position sensor 15 is connected to the electronic control device 30, and a detection signal corresponding to the rotation position of the vehicle model 11 is output to the electronic control device 30. Details of the electronic control unit 30 will be described later. A screen 14 is provided along the inner peripheral surface of the dome 12 around the vehicle model 11, that is, in the front, both sides, and the rear. A plurality of projectors 16 are provided above the dome 12 at positions and angles that can be projected onto the screen 14.

  The vehicle model 11 includes an operation system such as an accelerator pedal, a brake pedal, a steering wheel, and a shift lever, instruments such as a speedometer, a room mirror 17 for confirming the rear of the vehicle, a left door mirror 18, A right door mirror 19 and the like are provided. Here, the room mirror 17, the left door mirror 18, and the right door mirror 19 correspond to the rear viewing mirror described in the claims.

  Sensors for detecting the respective operation amounts are attached to the accelerator pedal, the brake pedal, the steering wheel, and the like. Similarly, a sensor for detecting the shift position is attached to the shift lever. These sensors are also connected to the electronic control unit 30, and the detection results detected by each sensor are output to the electronic control unit 30.

  The electronic control device 30 is also connected with a gaze direction detection camera 20 that images the driver's head (face) and acquires image data for detecting the gaze direction of the driver. Image data acquired by the line-of-sight direction detection camera 20 is output to the electronic control unit 30. The line-of-sight direction detection camera 20 is constituted by a CCD camera, and is attached to the upper surface of the steering column cover of the vehicle model 11, for example. The mounting position of the camera 20 for detecting the sight line direction is not limited to the upper surface of the steering column cover. The gaze direction detection camera 20 detects with high accuracy whether or not the driver's gaze direction, in particular, the driver's gaze direction is directed to the rearview mirror 17 and the left and right door mirrors 18 and 19 for confirming the rear of the vehicle. For example, it may be attached to the room mirror 17 and the left and right door mirrors 18 and 19.

  The electronic control unit 30 generates an image to be projected on the screen 14 based on the detection information from each sensor described above. The electronic control unit 30 includes a microprocessor that performs calculations, an internal memory that stores various data such as calculation results, and a storage device that stores programs and simulation images for causing the microprocessor to execute various processes. ing.

  The electronic control unit 30 detects the driver's line-of-sight direction based on the image data acquired by the line-of-sight direction detection camera 20, and stores the position information of the room mirror 17 and the left and right door mirrors 18, 19 stored in advance. Based on the detected line-of-sight direction, the line-of-sight direction calculation unit 31 that determines whether the driver is looking at the room mirror 17, the left door mirror 18, or the right door mirror 19, and the projector 16 project the image onto the screen 14. An image generation unit 32 that generates an image is constructed. In other words, the functions of the line-of-sight detection means and the display means described in the claims are realized by the line-of-sight direction calculation unit 31 and the image generation unit 32 that constitute the electronic control device 30.

  The line-of-sight calculation unit 31 receives image data of the driver's head acquired by the line-of-sight direction detection camera 20. The gaze direction calculation unit 31 first acquires the driver's gaze direction (gaze vector) from the input image data of the driver's head by performing processing based on the theory of pattern recognition and stereo stereoscopic vision. . More specifically, the line-of-sight direction is obtained by detecting the position, angle (orientation) of the driver's face, the position of the eye in the face, and the position of the black eye (eye position) in the eye from the image data. It is done. Subsequently, in the line-of-sight direction calculation unit 31, based on the position information (three-dimensional coordinates) of the room mirror 17 and the left and right door mirrors 18, 19 stored in advance and the obtained line-of-sight direction, the driver uses the room mirror 17, It is determined whether the left door mirror 18 or the right door mirror 19 is being viewed. The determination result is output to the image generation unit 32.

  In the image generation unit 32, the motion information of the vehicle model 11 is calculated according to the operation amount and shift position of the accelerator pedal, the brake pedal, and the steering wheel, and the current travel position in the simulation travel is based on the obtained motion information. Is calculated. Then, image information of the scenery that can be seen from inside the vehicle at the current traveling position is read, and an image signal for the projector 16 is generated from this image information. At that time, a determination result by the line-of-sight direction calculation unit 31, that is, an image signal generated depending on whether or not the driver is looking at the rear via the room mirror 17, the left door mirror 18, or the right door mirror 19 is changed. As a result, the image projected on the screen 14 installed around the vehicle model 11 is switched.

  More specifically, when it is determined that the driver is looking backward through the rearview mirror 17, the viewpoint is placed on the reflecting surface of the rearview mirror 17 in the area 14A on the screen 14 reflected in the rearview mirror 17. An image signal is generated so that the projected image is projected. Further, an image with the viewpoint on the reflecting surface of the left door mirror 18 is projected on the area 14B on the screen 14, and an image with the viewpoint on the reflecting surface of the right door mirror 19 is projected on the area 14C on the screen 14. An image signal is generated. Furthermore, an image signal is generated so that an image with the viewpoint at the position of the driver's eyeball is projected onto the other region 14G.

  On the other hand, when it is determined that the driver is looking backward through the left door mirror 18 or the right door mirror 19, the viewpoint is placed on the reflecting surface of the left door mirror 18 in the area 14E on the screen 14 reflected on the left door mirror 18. The projected image is projected, and an image signal is generated so that an image with the viewpoint on the reflecting surface of the right door mirror 19 is projected onto a region 14F on the screen 14 reflected on the right door mirror 19. In addition, an image signal is generated so that an image with the viewpoint on the reflection surface of the room mirror 17 is projected onto the region 14D on the screen 14. Furthermore, an image signal is generated so that an image with the viewpoint at the position of the driver's eyeball is projected onto the other region 14G.

  Further, when it is determined that the driver is looking back and looking directly behind, an image signal is generated so that an image with the viewpoint at the driver's eyeball position is projected onto the screen 14 behind the vehicle model 11. Is done. At this time, an image signal is generated so that an image with the viewpoint at the driver's eyeball position is projected onto the screen 14 in front of the vehicle model 11.

  The generated image signal is output to the projector 16. At that time, the projector 16 that outputs each image signal is selected according to the rotation position of the vehicle model 11 detected by the rotation position sensor 15.

  The projector 16 projects a simulation image such as an image of a landscape that can be seen from inside the vehicle when traveling on the traveling road in accordance with an image signal input from the electronic control device 30. The driver recognizes and determines the driving information (for example, information on the driving path, signs, signals, other vehicles, pedestrians, etc.) included in the simulation image projected on the screen 14 and operates the vehicle model 11. . The driving operation state is detected by each sensor and sent to the electronic control unit 30 as described above.

  Next, the operation of the image display apparatus 1 will be described with reference to FIG. FIG. 3 is a flowchart showing the processing procedure of the projection image switching process in the image display device 1.

  In step S100, the image data of the driver's face acquired by the camera 20 for detecting the eye direction is read, and the three-dimensional position and the eye direction of the driver's eyeball are detected from the read image data.

  In the subsequent step S102, the driver moves the left door mirror 18 or the right door mirror 19 based on the line-of-sight direction detected in step S100 and the position information (three-dimensional coordinates) of the left door mirror 18 and the right door mirror 19 stored in advance. A determination is made as to whether or not they are watching. In step S102, it is also determined whether or not the driver is looking forward or left and right. Here, when step S102 is affirmed, that is, when it is determined that the driver is looking at the left and right door mirrors 18 and 19, when it is determined that there is a high possibility of watching, or when looking at the front or left and right If it is determined that there is, the process proceeds to step S104. On the other hand, when step S102 is denied, that is, when all the above-described conditions are denied, the process proceeds to step S106.

  In step S104, an image with the viewpoint on the reflecting surface of the left door mirror 18 is projected onto an area 14E on the screen 14 reflected on the left door mirror 18, and the right door mirror 19 is projected onto an area 14F on the screen 14 reflected on the right door mirror 19. An image with a viewpoint on the reflection surface is projected. In addition, an image with the viewpoint on the reflecting surface of the room mirror 17 is projected onto the area 14D on the screen 14. Further, an image with the viewpoint placed on the driver's eyeball position is projected onto the other region 14G. Thereafter, the process proceeds to step S114.

  In step S106, based on the line-of-sight direction detected in step S100 and the position information (three-dimensional coordinates) of the room mirror 17 stored in advance, the driver is watching or watching the room mirror 17. A determination is made as to whether the property is high. Here, when it is determined that the driver is looking at the room mirror 17 or when it is determined that there is a high possibility that the driver is looking, the process proceeds to step S108. On the other hand, when it is determined that the driver is not looking at the room mirror 17 or when it is determined that the driver is not likely to be looking, the process proceeds to step S110.

  In step S <b> 108, an image with the viewpoint on the reflecting surface of the room mirror 17 is projected onto the area 14 </ b> A on the screen 14 reflected on the room mirror 17. Further, an image with the viewpoint on the reflecting surface of the left door mirror 18 is projected on the area 14B on the screen 14, and an image with the viewpoint on the reflecting surface of the right door mirror 19 is projected on the area 14C on the screen 14. Further, an image with the viewpoint placed on the driver's eyeball position is projected onto the other region 14G. Thereafter, the process proceeds to step S114.

  In step S110, a determination is made as to whether the driver is looking back and looking directly behind. Here, if it is determined that the driver is looking directly behind, the process proceeds to step S112. On the other hand, when this step is negative, the process proceeds to step S104 described above. Since the processing content in step S104 is as described above, description thereof is omitted here.

  In step S112, an image with the viewpoint placed on the driver's eyeball position is projected onto the screen 14 behind the vehicle model 11. In addition, an image with the viewpoint at the driver's eyeball position is also projected in front of the vehicle model 11. Thereafter, the process proceeds to step S114.

  After the process of step S104, S108, or S112 is completed, in step S114, a determination is made as to whether the simulation travel has been completed. Here, when it is determined that the simulation traveling has not ended yet, the process proceeds to step S100, and the above-described processing of steps S100 to S112 is repeatedly performed until it is determined that the simulation traveling has ended. Is done. On the other hand, when it is determined that the simulation traveling has ended, the present processing is ended.

  According to the driving simulator 10 according to the present embodiment, when it is determined that the driver is looking behind the room mirror 17 based on the detected line-of-sight direction of the driver, An image with the viewpoint on the reflecting surface of the room mirror 17 is projected onto the area 14A on the screen 14 to be projected. On the other hand, when it is determined that the driver is looking backward through the left door mirror 18 or the right door mirror 19, the viewpoint is placed on the reflecting surface of the left door mirror 18 in the area 14E on the screen 14 reflected on the left door mirror 18. The projected image is projected, and an image with the viewpoint on the reflecting surface of the right door mirror 19 is projected onto a region 14F on the screen 14 reflected on the right door mirror 19. Therefore, when the driver looks rearward through the room mirror 17 or the left and right door mirrors 18 and 19, it is possible to reproduce the same appearance as in reality.

  If it is determined that the driver is looking back and looking directly behind, an image with the viewpoint at the position of the driver's eyeball is projected onto the screen 14 behind the vehicle model 11. As a result, it is possible to reproduce the same appearance as when viewing directly behind. Here, when looking back through the rear view mirror 17 or the like, the direction of the face or the direction of the line of sight moves greatly, so that the detection can be easily performed. In general, looking back requires more time than moving only the line of sight. Therefore, when it is determined that the driver is looking back and looking directly behind, the image can be switched more appropriately by switching to an image with the viewpoint at the eyeball position of the driver.

  Next, a case where the image display apparatus according to the present invention is applied to a stereoscopic display system such as CAVE (Cave Automatic Virtual Environment: registered trademark) will be described as an example as a second embodiment.

  First, the configuration of a stereoscopic display system 40 to which the image display device 2 according to the second embodiment is applied will be described with reference to FIGS. 4 and 5 together. FIG. 4 is a diagram illustrating a main configuration of the stereoscopic display system 40. FIG. 5 is a block diagram showing a configuration of the image display device 2 applied to the stereoscopic display system 40.

  The stereoscopic display system 40 projects CG (computergraphic) images on a plurality of (six in this embodiment) screens 14 provided on each wall surface forming a substantially rectangular parallelepiped room RM by using the projector 16. A virtual reality space (virtual reality) is generated. A mirror 41 is provided inside the room RM, and the subject can check the back via the mirror 41 during the experiment.

  The image display device 2 is different from the first embodiment described above in that the rotation position sensor 15 is not provided. Further, the electronic control device 30B constituting the image display device 2 is the first in that a sensor for detecting an operation amount of an accelerator pedal, a brake pedal, a steering wheel, or the like or a sensor for detecting a shift position is not connected. Different from the embodiment. In the present embodiment, it is preferable that the gaze direction detection camera 20 is attached to the mirror 41 and configured to detect whether or not the subject has seen the mirror 41.

  Further, the image generation unit 32B constructed in the electronic control device 30B is different from the first embodiment in the following points. That is, in the image generation unit 32B, image information corresponding to the position and operating state of the subject is read, and an image signal for the projector 16 is generated from this image information. At that time, a determination result by the line-of-sight direction calculation unit 31, that is, an image signal generated depending on whether or not the subject is looking backward through the mirror 41 is changed. As a result, the image projected on the screen 14 installed on the inner wall surface of the room RM is switched. More specifically, when it is determined that the subject is looking behind through the mirror 41, an image with the viewpoint on the reflecting surface of the mirror 41 is projected onto the area 14H on the screen 14 reflected on the mirror 41. As a result, an image signal is generated. In addition, an image signal is generated so that an image with the viewpoint placed at the eyeball position of the subject is projected onto other regions. Note that the position and operation state of the subject may be detected by diverting the gaze direction detection camera 20, or may be detected by adding a dedicated sensor or the like.

  Other configurations are the same as or similar to those of the first embodiment described above, and thus the description thereof is omitted here.

  Next, the operation of the image display device 2 will be described with reference to FIG. FIG. 6 is a flowchart showing the procedure of the projection image switching process in the image display device 2.

  In step S200, the image data of the driver's face acquired by the camera 20 for detecting the eye direction is read, and the three-dimensional position and the eye direction of the driver's eyeball are detected from the read image data.

  In subsequent step S202, based on the line-of-sight direction detected in step S200 and the position information of the mirror 41 stored in advance, whether or not the subject is looking at the mirror 41 or is likely to be seen. Judgment is made. Here, when it is determined that the subject is looking at the mirror 41 or when it is determined that there is a high possibility that the subject is looking, the process proceeds to step S204. On the other hand, when step S202 is negative, the process proceeds to step S206.

  In step S <b> 204, an image with the viewpoint placed on the reflection surface of the mirror 41 is projected onto the area 14 </ b> H on the screen 14 that is reflected on the mirror 41. In addition, an image with the viewpoint at the position of the driver's eyeball is projected onto the other area. Thereafter, the process proceeds to step S208.

  When the subject does not look at the mirror 41 or when the possibility of viewing is low, an image with the viewpoint placed on the driver's eyeball position is projected on all areas of the screen 14 in step S206. Thereafter, the process proceeds to step S208.

  After the process of step S204 or S206 is completed, in step S208, it is determined whether or not the experiment is completed. Here, if it is determined that the experiment has not ended yet, the process proceeds to step S200, and the above-described steps S200 to S206 are repeatedly executed until it is determined that the experiment has ended. . On the other hand, when it is determined that the experiment has ended, the present process is ended.

  According to the stereoscopic display system 40 according to the present embodiment, when it is determined that the subject is looking through the mirror 41 based on the detected gaze direction of the subject, the screen reflected on the mirror 41 is displayed. 14 is projected on the reflection surface of the mirror 41 in the region 14H on the image 14. Therefore, when the subject looks behind through the mirror 41, the same appearance as in reality can be reproduced.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, the image display device according to the present invention is applied to a driving simulator or a stereoscopic display system. However, a system to which the present invention can be applied is not limited to a driving simulator or a stereoscopic display system. That is, the present invention can be widely applied to a system in which when a video is displayed, a case where the user directly views the video and a case where the video is viewed through a mirror are mixed.

  Needless to say, the display means for displaying the image is not limited to the projector.

It is a figure which shows the main structures of the driving simulator to which the image display apparatus which concerns on 1st Embodiment was applied. It is a block diagram which shows the structure of the image display apparatus which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the projection image switching process in the image display apparatus which concerns on 1st Embodiment. It is a figure which shows the main structures of the stereoscopic display system to which the image display apparatus which concerns on 2nd Embodiment was applied. It is a block diagram which shows the structure of the image display apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the process sequence of the projection image switching process in the image display apparatus which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Image display apparatus, 10 ... Driving simulator, 11 ... Vehicle model, 12 ... Dome, 13 ... Base, 14 ... Screen, 15 ... Rotation position sensor, 16 ... Projector, 17 ... Room mirror, 18 ... Left door mirror , 19: Right door mirror, 20: Camera for detecting the direction of gaze, 30, 30B: Electronic control unit, 31: Gaze direction calculating unit, 32, 32B: Image generating unit, 40 ... Stereoscopic display system, 41 ... Mirror.

Claims (4)

Display means for displaying an image on a display surface provided around the user;
A rear viewing mirror for the user to view the back;
Gaze detection means for detecting the gaze direction of the user,
The display means, when it is determined that the user is looking through the rear visual mirror based on the user's visual direction detected by the visual line detection means, the rear visual mirror An image display device, wherein an image created by placing a viewpoint on a reflection surface of the rear viewing mirror is displayed in an area of the display surface shown in FIG.   The image display apparatus according to claim 1, wherein the display unit is a projector that projects an image on a screen. With multiple rear view mirrors,
The display means is viewed by the user when it is determined that the user is looking behind through any rear view mirror based on the detected line-of-sight direction of the user. The image created by placing the viewpoint on the reflection surface of the rear viewing mirror that the user is viewing is displayed in the area of the display surface that is reflected on the rear viewing mirror. Image display device. The display means is an image created with a viewpoint at the eyeball position of the user when it is determined that the user is directly looking backward based on the detected line-of-sight direction of the user. The image display device according to claim 1, wherein:

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