Display device for vehicle

Abstract

To provide a display device for a vehicle capable of improving visibility.SOLUTION: A vehicular display device 1 according to the present embodiment includes a projector having a light source that generates display light and emitting the display light toward a transmissive screen 3 that transmits the display light and displays a video to be visually recognized by a viewer 5 outside a vehicle 2, and a control unit that causes the projector to display a main video 31 and a guidance video 41 for guiding a line of sight 5a of the viewer 5 to a direction other than a direction of the light source. The guidance video 41 may be displayed at a location other than the optical axis point LP that is an intersection point with the optical axis connecting the light source on the screen 3 and the viewpoint of the viewer 5.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a display device for a vehicle. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a technology is known in which a vehicle is equipped with a projector and an image to be displayed to a viewer outside the vehicle is projected onto a transmission screen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-018254 Summary of the Invention [Problem to be solved by the invention]

[0004] A transmissive screen allows a viewer to view an image by facing the projector's light source across the screen. Therefore, depending on the viewer's line of sight, the viewer may look directly at the light source, which can cause glare and annoyance from the resulting image.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a vehicle display device that can improve visibility. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the vehicle display device disclosed herein includes a projector having a light source that generates display light and emits the display light toward a transparent screen that transmits the display light and displays an image that can be seen by a viewer outside the vehicle, and a control unit that displays a main image and a guidance image on the projector to guide the viewer's gaze in a direction other than the light source. [Effects of the Invention]

[0007] The vehicle display device of the present disclosure can improve visibility. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram conceptually showing a vehicle and a vehicle display device according to an embodiment of the present invention mounted on the vehicle; [Figure 2] FIG. 10 is an explanatory diagram showing an example of a main video and optical axis points displayed on a transmissive screen. [Figure 3] FIG. 2 is a schematic functional block diagram showing a functional configuration of the vehicle display device. [Figure 4] 10 is a flowchart illustrating a gaze guidance process executed by the display device. [Figure 5] FIG. 10 is an explanatory diagram showing a first example of a guidance image. [Figure 6] FIG. 10 is an explanatory diagram showing a second example of a guidance image. [Figure 7] FIG. 10 is an explanatory diagram showing a third example of a guidance image. [Figure 8] FIG. 10 is an explanatory diagram showing a fourth example of a guidance image. [Figure 9] FIG. 10 is an explanatory diagram showing an example of a predetermined range used to determine whether or not a line of sight is directed to a light source point. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a vehicle display device according to the present disclosure will be described with reference to the accompanying drawings. The vehicle display device according to the present disclosure can be applied to any vehicle, such as an automobile, a motorcycle, an agricultural machine, a construction machine, etc. In this embodiment, an example in which the vehicle display device is mounted on an automobile will be described.

[0010] FIG. 1 is an explanatory diagram conceptually showing a vehicle 2 and a vehicle display device 1 mounted on the vehicle 2 according to this embodiment. FIG. 2 is an explanatory diagram showing an example of the main video 31 and optical axis point LP displayed on the transmissive screen 3. As shown in FIG. FIG. 3 is a schematic functional block diagram showing the functional configuration of the vehicle display device 1. As shown in FIG.

[0011] In the following description, "front," "rear," "right," "left," "up," and "down" follow the definitions of "Fr.", "Re.", "R," "L," "To.", and "Bo." in Figures 1, 2, and 5 to 9. "Front" refers to the direction in which vehicle 2 is traveling, and "rear" refers to the opposite direction to the direction in which vehicle 2 is traveling.

[0012] The vehicle display device 1 (hereinafter referred to as "display device 1") has a control unit 10 and a projector 20. The control unit 10 and the projector 20 may be housed in a single housing and configured as an integrated unit, or may be located in different locations. The display device 1 (projector 20) is placed at a required position in the vehicle 2 where it can project display light L onto a transmissive screen 3 (hereinafter referred to as "screen 3") described below. The display device 1 may be placed on the ceiling 2a of the vehicle 2, on a wall, in a seat, between seats, on the floor, or the like, for example, as shown in FIG. 1, and the position at which it is placed is not limited.

[0013] The control unit 10 includes a gaze detection unit 11, a determination unit 12, and a display control unit 13.

[0014] The gaze detection unit 11 acquires image data captured by the camera 15 and detects the gaze 5a and viewpoint of a viewer 5 outside the vehicle 2 (hereinafter referred to as "viewer 5"). The camera 15 is located at a position where it can acquire image data necessary to detect the presence or absence of the viewer 5, and the gaze 5a and viewpoint position of the viewer 5, and is disposed, for example, inside or outside the vehicle 2. The camera 15 may be a component of the display device 1 or a component of the vehicle 2. When the camera 15 is a component of the vehicle 2, the gaze detection unit 11 acquires the image data via a wired or wireless connection.

[0015] The gaze detection unit 11 detects the presence or absence of the viewer 5, the gaze 5a, etc., using, for example, a known image processing technique. The gaze detection unit 11 estimates and detects the gaze 5a of the viewer 5 by using, for example, information such as the positional relationship between the center of the pupil and characteristic points around the eye, the position of the corneal reflex, the movement of muscles around the eye, eye movement, head movement, and facial and body posture, either alone or in combination.

[0016] Based on the line of sight 5a detected by the line of sight detection unit 11, the determination unit 12 determines whether or not the line of sight 5a of the viewer 5 coincides with a predetermined direction.

[0017] The display control unit 13 controls the projector 20 to display a main image 31 and a guidance image 41 on the screen 3. The main image 31 is, for example, a text message 32 (such as "WELCOME" shown in FIG. 2) directed to a driver or passenger who is about to get into the vehicle 2 and is located outside the vehicle 2, or various other images such as an advertisement displayed for a third party located outside the vehicle 2. The guidance image 41 is an image for guiding the line of sight 5a of the viewer 5 in a direction other than the direction of the projector 20 (its light source).

[0018] The projector 20 has a known configuration including a light source, an optical system, a display panel, a control circuit, etc. The projector 20 generates display light L related to a required image based on instructions from the display control unit 13, and emits the display light L to the screen 3. The projector 20 has three light sources of, for example, red, green, and blue, and generates display light L related to an image in the required colors. Note that the display light L emitted from the projector 20 is display light L related to an image that is an inverted version of the image displayed on the screen 3 and viewed by the viewer 5.

[0019] The screen 3 transmits the display light L and displays an image to be viewed by a viewer 5 outside the vehicle 2. The screen 3 is disposed in a position where the viewer 5 can view the image, such as on a side window 2b, rear window, or front window. The screen 3 may be a sheet attached to the window, or may be disposed inside the window as a diffusion layer.

[0020] Next, a description will be given of the gaze guidance process executed by the display device 1 in this embodiment. Fig. 4 is a flowchart illustrating the gaze guidance process executed by the display device 1. This gaze guidance process is executed at any time during a period in which the main video 31 can be displayed, for example.

[0021] The gaze guidance process described below is a process that is executed to prevent the viewer 5 from unintentionally looking directly at the light source when viewing the main image 31, due to the characteristics of the transmissive screen 3, where the viewer 5 and the light source of the projector 20 face each other across the screen 3. Specifically, the gaze guidance process is a process that displays a guidance image 41, different from the main image 31, on the screen 3 at a location other than the optical axis point LP, which is the intersection point with the optical axis LA that connects the light source and the viewpoint of the viewer 5, in order to guide the line of sight 5a of the viewer 5 in a direction other than the light source.

[0022] In step S1, the control unit 10 determines whether it is time to project the main video 31. The time to project the main video 31 occurs, for example, when the control unit 10 detects that a person is approaching the vehicle 2. When the control unit 10 determines that it is not time to project the main video 31 (NO in step S1), the control unit 10 waits until it is time to project the main video 31.

[0023] On the other hand, if it is determined that it is time to project the main image 31 (YES in step S1), in step S2, the display control unit 13 causes the projector 20 to generate the main image 31 including a text message 32 such as "WELCOME" as shown in FIG. 2, and project it onto the screen 3.

[0024] In step S3, the gaze detection unit 11 acquires image data captured by the camera 15. The gaze detection unit 11 detects the gaze 5a of the viewer 5 from the acquired image data. The gaze detection unit 11 continues acquiring image data until this process is completed. In step S4, the determination unit 12 determines whether the gaze 5a of the viewer 5 is in the direction of vehicle 2. This determination is made to determine whether the main image 31 is within the field of view of the viewer 5, and determines whether the gaze 5a is within the field of view based on whether the gaze 5a intersects with any point on vehicle 2. If the determination unit 12 determines that the gaze 5a is not in the direction of vehicle 2 (NO in step S4), the viewer 5 is unlikely to see the light source and there is no need to guide the gaze 5a, so the process is terminated.

[0025] On the other hand, if it is determined that the line of sight 5a is in the direction of vehicle 2 (YES in step S4), then in step S5, the display control unit 13 determines that there is a possibility that the viewer 5 will view the light source, and displays a guidance image 41 for guiding the line of sight 5a. The guidance image 41 may be placed anywhere on the screen 3 other than the optical axis point LP, which is the intersection point with the optical axis LA connecting the light source and the viewpoint of the viewer 5. For example, the guidance image 41 is displayed near the periphery of the screen 3, far from the optical axis point LP.

[0026] Furthermore, the guidance image 41 may be displayed at a suitable position depending on the position of the projector 20 (light source). For example, if the projector 20 is placed above the viewpoint of the viewer 5 (for example, on the ceiling 2a), the guidance image 41 is displayed below the viewpoint of the viewer 5, where the viewer 5 is unlikely to look directly at the light source. On the other hand, if the projector 20 is placed below the viewpoint of the viewer 5 (for example, on the floor), the guidance image 41 is displayed above the viewpoint of the viewer 5, where the viewer 5 is unlikely to look directly at the light source. Furthermore, if the determination unit 12 acquires the viewpoint position of the viewer 5 and determines that the projector 20 is above the viewpoint, the guidance image 41 may be displayed below the viewpoint of the viewer 5. On the other hand, if the determination unit 12 determines that the projector 20 is below the viewpoint, the guidance image 41 may be displayed above the viewpoint of the viewer 5.

[0027] 5 is an explanatory diagram showing a first example of guidance image 41. The first example of guidance image 41 is a dot-shaped figure displayed in a highly eye-catching warm color such as red, orange, or yellow, or a color complementary to the background color of main image 31, and is displayed by lighting up or blinking.

[0028] 6 is an explanatory diagram showing a second example of the guidance image 41. The second example of the guidance image 41 is an image in which a part of the main image 31 is hollowed out by increasing the transparency of the display area of ​​the guidance image 41 or by hiding the main image 31, for example, in order to enhance the eye-catching effect.

[0029] 7 is an explanatory diagram showing a third example of guidance image 41. The third example guidance image 41 is a reduced image of text message 32 (WELCOME), which is part of main image 31. While guidance image 41 is displayed, text message 32, which is part of main image 31, is hidden. This gives the viewer 5 the impression that text message 32, which is part of main image 31, has moved.

[0030] FIG. 8 is an explanatory diagram showing a fourth example of guiding image 41. The guiding image 41 as the fourth example can be displayed when the vehicle 2 visible to the viewer 5 has a display unit other than a screen (sub-display unit 4). The display unit is, for example, a transmissive screen disposed in a window different from the window in which the screen 3 on which the main image 31 is displayed is disposed, or various other display units such as a liquid crystal display disposed on the exterior of the vehicle 2. For example, as shown in FIG. 8, the guiding image 41 may be similar to the guiding image 41 as the first example, or may be similar to the guiding image 41 as the second or third example.

[0031] In step S6, the determination unit 12 determines whether or not the line of sight 5a of the viewer 5 (the intersection of the line of sight 5a and the screen 3) is at a location other than the optical axis point LP. At this time, the determination unit 12 may determine whether or not the line of sight 5a is outside a predetermined range 3a defined around the optical axis point LP, rather than just the narrow range of the optical axis point LP. Here, FIG. 9 is an explanatory diagram showing an example of the predetermined range 3a used to determine whether or not the line of sight 5a is toward the optical axis point LP. The predetermined range 3a used for the determination may be an area obtained by reducing the display area of ​​the screen 3, as shown in FIG. 9.

[0032] The determination unit 12 may also determine whether the line of sight 5a is at a location other than the optical axis point LP based on whether the line of sight 5a is directed toward the guidance image 41. Specifically, the determination unit 12 may determine whether the line of sight 5a is directed toward the guidance image 41 displayed at the lower rear position of the screen 3 in FIG.

[0033] If the determination unit 12 determines that the line of sight 5a is not at any location other than the optical axis point LP, that is, that the line of sight 5a is at the optical axis point LP (NO in step S6), it determines in step S7 whether a predetermined time has elapsed since the guiding image 41 was displayed. This determination is made in order to consider that the viewer 5 is not feeling dazzled by the light source if it is determined in step S6 that the line of sight 5a is at the optical axis point LP and the predetermined time has elapsed since the guiding image 41 was displayed. If it is determined that the predetermined time has not yet elapsed (NO in step S7), the process returns to step S6 and the subsequent processes are repeated.

[0034] On the other hand, if it is determined that the predetermined time has elapsed (YES in step S7) and if it is determined that the line of sight 5a is at a location other than the optical axis point LP (YES in step S6), then in step S8, the display control unit 13 determines that the viewer 5 is not feeling dazzled by the light source and that the guidance image 41 is unnecessary, and hides the guidance image 41. In other words, the display control unit 13 displays only the main image 31 on the screen 3.

[0035] When guiding video 41 is made invisible, if it is instantly erased from the screen 3 or the like, it may cause discomfort to the viewer 5. For this reason, the display control unit 13 may perform various visual effects when transitioning to invisible video. For example, the display control unit 13 may fade out the guiding video 41 outside the screen 3. Furthermore, when displaying the guiding video 41 as a third example, the display control unit 13 may gradually enlarge the guiding video 41, which is an image obtained by reducing the size of the text message 32 that is part of the main video 31, and transition it to the original main video 31.

[0036] The display device 1 in this embodiment can provide a visual effect by displaying the main image 31 to the viewer 5 outside the vehicle 2, and at the same time, it can prevent the viewer 5 from suddenly looking directly at the strong light from the light source while looking at the main image 31, thereby reducing the glare and annoyance felt by the viewer 5.

[0037] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0038] For example, in the gaze guidance processing, whether or not to display the guidance image 41 is determined based on whether or not the line of sight 5a of the viewer 5 is in the direction of the vehicle 2. Alternatively, the determination unit 12 may determine whether or not the viewer 5 is within a predetermined distance from the vehicle 2, based on image data captured by the camera 15. The predetermined distance used for the determination in this case is preferably set according to the distance at which the viewer 5 feels dazzled when viewing the light source, which is experimentally determined according to the luminance of the light source. [Explanation of symbols]

[0039] 1. Vehicle display device (display device) 2 vehicles 2a ceiling 2b Side window 3. Transparent screen (screen) 4 Sub display 5. Viewer 5a line of sight 10 Control Unit 11. Gaze detection unit 12 Judgment section 13 Display control unit 15 Camera 20 Projectors 31 Main Video 32. Text Messages 41 Guiding Video L display light LA optical axis LP light source point

Claims

1. a projector having a light source that generates display light, and emitting the display light toward a transmission screen that transmits the display light and displays an image that can be viewed by a viewer outside the vehicle; The vehicle display device includes a control unit that displays a main image and a guidance image for guiding the viewer's line of sight in a direction other than the light source, in the projector.

2. The vehicle display device according to claim 1 , wherein the guidance image is displayed at a location other than an optical axis point on the screen, which is an intersection point of an optical axis connecting the light source and the viewer's viewpoint.

3. The vehicle display device according to claim 1 , wherein the control unit displays the guidance image when the viewer's line of sight is in the direction of the vehicle.

4. The vehicle display device according to claim 2 , wherein the control unit does not display the guidance image when the viewer's line of sight is at a point other than the optical axis point.

5. 5. The vehicle display device according to claim 4, wherein the location other than the optical axis point is outside a predetermined range defined around the optical axis point.

6. The vehicle display device according to claim 1 , wherein the control unit terminates the display of the guidance image when a predetermined time has elapsed since the guidance image was displayed.

7. The vehicle display device according to claim 1 , wherein the guidance image is different from the main image.

8. the guidance image is an image obtained by reducing a portion of the main image, The vehicle display device according to claim 1 , wherein the control unit hides a part of the main image while the guidance image is displayed.

9. Further, a sub-display unit different from the screen is provided, The vehicle display device according to claim 1 , wherein the guidance image is displayed on the sub-display unit.

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