Head-up display device, control method for head-up display device, display control program, and on-vehicle display system

Abstract

The present invention makes it possible for a display image such as a route guide image to give the same impression to a driver who is a viewer without depending on the position of an eye box. This head-up display device (HUD device 100) forms an image by superimposing a foreground in a front field of view of a vehicle and one or more virtual images on a virtual image formation plane virtually set in front of the vehicle, and causes a viewer riding in the vehicle to visually recognize the image. The head-up display device includes an image display unit 30 that displays a route guide image, and a control unit 10 that performs perspective adjustment for imparting a sense of perspective to the route guide image. The control unit 10 performs control for varying the intensity of the perspective adjustment for imparting the sense of perspective in accordance with an elevation angle that is an angle formed by a virtual line parallel to a road surface from the position of an eye of the viewer in a height direction and a straight line connecting the position of the eye of the viewer in the height direction and the center of the virtual image formation plane, and displaying a virtual image generated by the perspective adjustment on the image display unit 30.

Description

Head-up display device, control method for head-up display device, display control program, and in-vehicle display system

[0001] The present invention relates to a head-up display device, etc., that superimposes a virtual image onto a virtual image-forming surface virtually set up in front of the vehicle, and projects the foreground in the vehicle's forward field of view onto the virtual image, allowing a viewer inside the vehicle to see it.

[0002] For example, Patent Document 1 describes a technology for a head-up display device (HUD device) for an AR (virtual reality) navigation device that superimposes virtual visual information (virtual images), such as route guidance images, onto the scenery (foreground) in front of the vehicle in the real world (see paragraph

[0008] of Patent Document 1). According to the technology described in Patent Document 1, route guidance images (virtual images) represented by arrow marks, etc., can be projected onto a virtual image forming surface virtually set in front of the vehicle, for example, on roads in the real world where it is necessary to guide the direction of travel of the vehicle at intersections, etc. Therefore, the driver, who is the viewer, can view the route guidance images without having to move their eyes significantly while driving, thus contributing to safe driving.

[0003] Furthermore, Patent Document 1 describes a mechanism for changing the position of the eyebox by rotating an optical element (for example, a concave mirror in an imaging optical system) incorporated into a HUD device, so that drivers of various heights (viewers with different viewpoint positions in the height direction) can accurately view virtual images such as route guidance images without increasing the size of the device (see paragraphs

[0066] to

[0075] , Figures 12 and 14 of Patent Document 1). As the position of the eyebox, which is the region in which virtual images can be viewed, moves due to the rotation of the concave mirror, there is a one-to-one correspondence between the position of the eyebox and the degree of rotation of the concave mirror (rotation angle or position) due to its optical properties. Therefore, it is possible to easily estimate the height of the driver who is riding in the vehicle as a viewer based on the degree of rotation of the concave mirror. For example, if the degree of rotation of the concave mirror falls within a predetermined range of values ​​in the ± direction of a predetermined angle reference value, it can be determined that "a short (tall) person is riding in the vehicle."

[0004] International Publication No. 2020-009218 (see paragraphs

[0008] ,

[0066] to

[0075] , Figures 12 and 14)

[0005] However, according to the technology described in Patent Document 1, if the position of the eye box is changed by rotating an optical element (concave mirror of the imaging optical system), the display position (height from the road surface) of the route guidance image may change, for example, and the driver may not perceive the route guidance image as being located at the target position in the foreground. In other words, the relationship between the foreground in the vehicle's forward field of view and the route guidance image superimposed on that foreground may be perceived differently, and the impression received from the displayed image may change depending on the height and build of the driver who is viewing it (for example, it may give the impression that the point to turn at an intersection is pointing to a different location). Furthermore, even content that is not superimposed on the foreground, such as ADAS (Advanced Driver Assist System) status and warning icons, can be bothersome (obtrusive) to drivers, especially those who are short, as the display may enter their effective field of view. Patent Document 1 does not mention any of these problems, nor does it mention any countermeasures.

[0006] Therefore, the object of the present invention is to provide a head-up display device, etc., that can give the same impression to the driver, who is the viewer, regardless of the position of the eye box, when displaying images such as route guidance images.

[0007] Other objects of the present invention will become apparent to those skilled in the art by referring to the embodiments and best embodiments described below, as well as the accompanying drawings.

[0008] The following are examples of embodiments of the present invention to facilitate understanding of its outline.

[0009] A first aspect of the present invention is a head-up display device that superimposes one or more virtual images onto a virtual image forming surface virtually set in front of a vehicle, and allows a viewer riding in the vehicle to view them, comprising: an image display unit that displays a route guidance image; and a control unit that performs perspective adjustment to give the route guidance image a sense of depth, wherein the control unit varies the intensity of the perspective adjustment that gives the route guidance image a sense of depth according to the downward angle which is the angle between a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, and controls the display of the virtual image generated by the perspective adjustment on the image display unit.

[0010] Here, "the position of the viewer's eyes in the height direction" refers to, for example, the eye point EP (viewpoint position) of the viewer, the driver DR, as shown in Figure 1, and is detected, for example, by the viewpoint position detection device 301 shown in Figure 2. Furthermore, the virtual image V displayed by the head-up display device is correctly viewed within a predetermined limited area (eye box EB). Therefore, since it can be estimated that the eye point EP of the viewer, the driver DR, is located within the eye box EB, information regarding the viewer's eye position in the height direction (eye point EP) can be replaced by information regarding the position of the eye box EB. The position of the eye box EB and the position of the virtual image forming surface (display area VA) virtually set in front of the vehicle correspond to each other (when the eye box moves, the display area VA also moves accordingly), so it can be determined by the downward angle LD (position of the eye box), which is the angle formed by the straight line connecting the viewer's eye position in the height direction and the center of the display area VA.

[0011] Furthermore, "perspective adjustment" is an image processing technique that adds a sense of depth to an image using linear perspective (one-point perspective). For example, when projecting a route guidance image represented by arrow marks onto a virtual image forming surface (display area VA) virtually set up in front of the vehicle, it refers to adjusting the vanishing point position according to the position of the eyebox to generate a virtual image with a changed length of the arrow mark. When creating an image using linear perspective and placing each object in the image at its respective depth position, a straight line is virtually drawn radially from a predetermined vanishing point, and by aligning the contour line of each object with that straight line, each object is fixed and perceived at its predetermined depth position. A virtual image expressed using linear perspective to be placed parallel to the road surface is a trapezoid, and linear perspective is used to express the intersection of the extension of the left side and the extension of the right side of the trapezoid to coincide with the intersection (vanishing point) of the actual scene (the vehicle's driving lane), thereby allowing for a pictorial representation where the virtual image appears to be placed parallel to the surface of the driving lane (road surface).

[0012] In the first embodiment, the control unit controls the intensity of perspective adjustment for the route guidance image (virtual image V), which is represented by, for example, an arrow mark, according to the depression angle (position of the eye box), and displays the generated perspective image on the image display unit. For this reason, for example, as shown in Figure 6A, when the position of the eye box rises due to the height of the viewer (in the case of a tall viewer "Taller"), the control unit adjusts the position of the vanishing point of the route guidance image to the far side VP because the route guidance image, represented by the arrow mark, is displayed lower (before countermeasures are implemented). １ Perspective image V with lengthened arrow by adjusting the perspective in an upward direction. Ｔ (After countermeasures) The control unit generates and displays the image on the image display unit. On the other hand, as shown in Figure 6B, when the position of the eye box is lowered due to the height of the viewer (in the case of a viewer with a short stature, "Shorter"), the control unit controls the vanishing point of the route guidance image, which is represented by an arrow mark, to be displayed higher up (before countermeasures), and the vanishing point of the route guidance image is moved to the front (downward) VP ２ Perspective image V with the arrow length shortened in the direction it points. ＳThe system generates (after the countermeasure) and controls it to display it on the image display unit.

[0013] In this way, the control unit changes the intensity of perspective adjustment to the route guidance image according to the downward angle (position of the eyebox). For example, for relatively tall viewers, the perspective adjustment is weakened by moving the vanishing point of the route guidance image, represented by an arrow mark, towards the back (upwards), thereby generating a perspective image (virtual image) with a longer arrow length. On the other hand, for relatively short viewers, the perspective adjustment is strengthened by moving the vanishing point of the route guidance image towards the front (downwards), thereby generating a perspective image (virtual image) with a shorter arrow length and displaying it on the image display unit. By doing so, depending on the downward angle (position of the eyebox), the route guidance image (virtual image) indicating a point to turn at an intersection, for example, does not give the impression that it is pointing to a different point than the actual turn, thus eliminating the problem of the relationship between the foreground and the virtual image being perceived differently depending on the viewer's height and build.

[0014] Therefore, according to the first embodiment, the displayed image (in this case, a route guidance image represented by arrow marks displayed as a virtual image) is displayed as a virtual image (perspective image) of the route guidance image at the target position in the foreground, regardless of the downward angle (position of the eye box), and a head-up display device can be provided that can give the same impression to drivers who are viewers of different heights and builds. Furthermore, in the case of content that does not overlap the foreground, such as ADAS status and warning icons, the display image is suppressed from entering the effective field of view, especially for drivers of short stature, thus eliminating the feeling of annoyance (being in the way).

[0015] In a second embodiment dependent on the first embodiment, the optical member has a curved reflective surface that projects the virtual image onto the virtual image forming surface, and the control unit may perform control to vary the intensity of the perspective adjustment based on the depression angle, which is adjusted by rotating the optical member.

[0016] The downward angle adjustment is performed by the driver, who is the viewer, rotating the concave mirror 141 of the imaging optical system 130, 140, which is an optical component, by operating, for example, the operation input device 302 shown in Figure 2. The position of the eyebox is determined by the direction of the display light emitted from the head-up display device (for example, the position projected onto the windshield WS in Figure 1), and therefore changes according to the angle and / or position of the optical component (concave mirror 141 of the imaging optical system 130, 140) within the head-up display device that determines the direction of the display light emitted from the head-up display device. Therefore, information regarding the position of the eyebox (information regarding the position of the viewer's eyes in the height direction) can be replaced, for example, by information regarding the angle and / or position of the concave mirror 141. Therefore, for example, as shown in Figure 1, the depression angle LD, which is the angle formed by the line connecting the driver DR's eye position in the height direction (viewpoint position EP) and the center of the virtual image plane (display area VA), can be determined by the angle and / or position of the concave mirror 141.

[0017] In the second embodiment, the control unit controls the intensity of perspective adjustment based on the downward angle LD (position of the eye box EB), which is adjusted by rotating an optical element (concave mirror 141 of the imaging optical system). For example, without relying on the viewpoint position detection device 301 shown in Figure 2, the estimated position of the eye box EB does not give the impression of pointing to a different location than where one should turn, such as an intersection, and the relationship between the foreground and the virtual image is perceived differently depending on the viewer's build. Therefore, the displayed image (in this case, a route guidance image represented by arrow marks displayed as virtual images) can give the same impression to drivers with different builds, regardless of the downward angle LD (position of the eye box EB).

[0018] In a third embodiment dependent on the first or second embodiment, the control unit may perform control to weaken the intensity of the perspective adjustment when the depression angle is smaller than a predetermined angle reference value, and control to strengthen the intensity of the perspective adjustment when the depression angle is larger than the predetermined angle reference value.

[0019] Here, the "predetermined angle reference value" is a value determined by specifications (specifications) of the head-up display device through verification etc. (experiments and simulations). For example, the angle reference value LD obtained from the verification results when the viewing angle is 10° × 3° and the image plane distance is 10 [m]. ＴＨ is pre-stored in a predetermined area of the storage unit 20 shown in FIG. 2. In the third aspect, the control unit weakens the intensity of the perspective adjustment when the depression angle LD is smaller than the predetermined angle reference value LD ＴＨ and strengthens the intensity of the perspective adjustment when the depression angle LD is larger than the predetermined angle reference value LD ＴＨ to perform control.

[0020] For example, in the case of a relatively tall viewer whose depression angle LD is larger than the predetermined angle reference value LD ＴＨ (for example, in the case of "Taller" shown in FIG. 6A), since the route guidance image is displayed below compared to the position of the normal eye box EB ("Normal") (before countermeasure), the perspective adjustment is performed in the direction towards the VP １ located higher. For example, a perspective image V Ｔ (virtual image V) with the length of the route guidance image represented by an arrow mark corrected to be longer is generated and projected and displayed on a virtual image formation plane (display area VA) set in front of the vehicle CR (after countermeasure). On the other hand, in the case of a relatively short viewer whose depression angle LD is smaller than the predetermined angle reference value LD ＴＨ (for example, in the case of "Shorter" shown in FIG. 6B), since the route guidance image is displayed above compared to the position of the normal eye box EB ("Normal") (before countermeasure), the perspective adjustment is performed in the direction towards the VP ２ located lower. For example, a perspective image V Ｓ with the length of the route guidance image represented by an arrow mark corrected to be shorter is generated and projected and displayed on a virtual image formation plane (display area VA) set in front of the vehicle CR (after countermeasure).

[0021] Therefore, according to the third embodiment, the display image (in this case, a route guidance image represented by an arrow mark displayed as a virtual image) does not give the impression that it points to a different point than where the driver should turn, for example, at an intersection, depending on the downward angle LD (position of the eye box EB), and the problem of the relationship between the foreground and the virtual image being perceived differently depending on the driver's build is eliminated. Therefore, it is possible to provide a head-up display device in which the display image can give the same impression to viewers with different builds, regardless of the downward angle (position of the eye box).

[0022] In a fourth embodiment dependent on the first to third embodiments, the control unit may perform control to move the display position of the virtual image downward by a predetermined amount when the depression angle is smaller than the predetermined angle reference value, and control to move the display position of the virtual image upward by a predetermined amount when the depression angle is larger than the predetermined angle reference value.

[0023] Here, "determined amount" refers to the amount of movement of the display position of the virtual image in the virtual image imaging plane (display area VA) optimized for each depression angle LD (position of the eye box EB) (the display position of the virtual image in the display area VA, where the angle and / or position of the rotationally driven optical element (concave mirror 141 shown in Figures 2, 3A, and 3B) is adjusted), which is a value determined by the verification described above and is a value pre-stored in a predetermined area of ​​the storage unit 20 shown in Figure 2. In the fourth embodiment, the control unit determines that the depression angle LD is a predetermined angle reference value LD ＴＨ If the value is smaller, control is performed to set the display position of the perspective image (virtual image) downward by a predetermined amount, and the depression angle LD is set to a predetermined angle reference value LD. ＴＨ If the value is greater, control is performed to set the display position of the perspective image (virtual image) upwards. For example, as shown in Figure 7A, when the position of the eye box EB (downward angle LD) is "Taller", the perspective image V is set higher compared to the "Normal" position. Ｔ Because the (virtual image) is displayed lower, the perspective image V is positioned higher above the virtual image plane (display area VA). ＴThe display position is changed to position the (virtual image), while on the other hand, for example, as shown in Figure 7B, when the position of the eye box EB (downward angle LD) is "Shorter", the perspective image V is different compared to the "Normal" position. Ｓ Because the (virtual image) is displayed at the top, the perspective image V is moved a predetermined amount further down from the virtual image plane (display area VA). Ｓ Control is performed to change the display position so that the (virtual image) is positioned. This allows the perspective image V, which is the foreground and virtual image, to be displayed regardless of the position of the eye box EB. Ｔ Or V Ｓ This allows for the maintenance of a relationship with the driver and provides a head-up display device that can give the same impression to drivers with different physical characteristics (as if a virtual image were located at the target position in the foreground).

[0024] A fifth aspect of the present invention is a control method for a head-up display device comprising: an image display unit that displays a route guidance image, which is formed by superimposing the foreground in the forward field of view of the vehicle and one or more virtual images onto a virtual image forming surface virtually set in front of the vehicle, and allowing a viewer in the vehicle to view it; an optical member having a curved reflective surface that projects the route guidance image onto the virtual image forming surface; and a control unit that controls the rotational drive of the image display unit and the optical member to perform perspective adjustment to give a sense of depth to the route guidance image, wherein the control unit controls the operation of the viewer The control method for a head-up display device comprises the steps of: estimating a depression angle, which is the angle formed by a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, by rotating the optical member by the device; and controlling the control unit to vary the intensity of the perspective adjustment performed on the route guidance image according to the estimated depression angle, and to display the virtual image generated by the perspective adjustment on the image display unit.

[0025] In the fifth embodiment, the control unit changes the intensity of perspective adjustment to the route guidance image according to the estimated depression angle LD (position of the eye box EB). For example, for a relatively tall viewer, the perspective adjustment is performed in the direction of weakening the vanishing point of the route guidance image represented by an arrow mark towards the far side (upwards), thereby generating a perspective image (virtual image) with a longer arrow length. On the other hand, for a relatively short viewer, the perspective adjustment is performed in the direction of strengthening the vanishing point of the route guidance image towards the foreground (downwards), thereby generating a perspective image (virtual image) with a shorter arrow length and displaying it on the image display unit. This prevents the viewer from getting the impression that the route guidance image (virtual image) indicating a point to turn at an intersection, for example, is pointing to a different point than the point to turn, and eliminates the problem of the relationship between the foreground and the virtual image being perceived differently depending on the viewer's height and build.

[0026] Therefore, according to the fifth embodiment, the displayed image (a route guidance image represented by arrow marks displayed as virtual images) is displayed as a perspective image (virtual image) for route guidance at the target position in the foreground, regardless of the downward angle LD (position of the eye box EB), and drivers with different heights and builds can be given the same impression. In addition, in the case of content that does not overlap the foreground, such as ADAS status and warning icons, the display image is suppressed from entering the effective field of view, especially for drivers with short stature, thus eliminating the feeling of annoyance (being in the way).

[0027] A sixth aspect of the present invention is a display control program for a head-up display device comprising: an image display unit that displays a route guidance image for which a foreground in the forward field of view of the vehicle and a virtual image are superimposed and imaged on a virtual image forming surface virtually set in front of the vehicle, and for a viewer riding in the vehicle to view; an optical member having a curved reflective surface that projects the route guidance image onto the virtual image forming surface; and a control unit that controls the rotational drive of the image display unit and the optical member to perform perspective adjustment to give a sense of depth to the route guidance image, wherein the processor of the control unit performs a process of estimating a depression angle, which is the angle formed by a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, which is adjusted by rotating the optical member by the viewer's operation; This is a display control program that performs a process to vary the intensity of the perspective adjustment applied to the virtual path guidance image according to the estimated depression angle, and to control the display of the virtual image generated by the perspective adjustment on the image display unit.

[0028] In the sixth embodiment, the processor in the control unit reads and executes a program stored in memory to vary the intensity of perspective adjustment to the route guidance image according to the estimated downward angle LD (position of the eyebox EB), and controls the display of the generated perspective image (virtual image) on the image display unit. Therefore, depending on the downward angle LD (position of the eyebox EB), it is possible to eliminate the problem of the relationship between the foreground and the virtual image being perceived differently depending on the height and build of the viewer, without giving the impression that the image points to a different location than where a turn should be made, such as an intersection. As a result, the displayed image (in this case, the route guidance image represented by arrow marks displayed as virtual images) can give the same impression to drivers with different heights and builds, regardless of the position of the eyebox. Furthermore, in the case of content that does not overlap the foreground, such as ADAS status or warning icons, even for short drivers, the display image is suppressed from entering the effective field of view, eliminating the problem of it being bothersome (intrusive).

[0029] A seventh aspect of the present invention is an in-vehicle display system comprising: a navigation device for providing route guidance; and a head-up display device that superimposes the foreground in the vehicle's forward field of view and a route guidance image generated by the navigation device onto a virtual image forming surface virtually set in front of the vehicle, and displays the image on the head-up display device for viewing by a viewer in the vehicle, wherein the head-up display device comprises: an image display unit for displaying the route guidance image; an optical member having a curved reflective surface for projecting the route guidance image onto the virtual image forming surface; and a control of the rotational drive of the image display unit and the optical member. The in-vehicle display system includes a control unit that performs perspective adjustment to give a sense of depth to the route guidance image, wherein the control unit estimates a depression angle, which is the angle formed by a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, adjusted by rotating the optical member at the operation of the viewer, varies the intensity of the perspective adjustment performed on the route guidance image according to the estimated depression angle, and controls the display of the virtual image generated by the perspective adjustment on the image display unit.

[0030] In the seventh embodiment, the control unit of the head-up display device varies the intensity of perspective adjustment for the route guidance image generated by the navigation device according to the adjusted downward angle LD (position of the eye box EB), and controls the display of the generated perspective image (virtual image) on the image display unit. Therefore, depending on the position of the eye box EB (downward angle LD), it is possible to eliminate the problem of the relationship between the foreground and the virtual image being perceived differently depending on the height and build of the viewer, without giving the impression that the image points to a different location than where a turn should be made, such as an intersection. As a result, it is possible to provide an in-vehicle display system in which the displayed image (in this case, the route guidance image represented by arrow marks displayed as virtual images) can give the same impression to drivers who are viewers of different heights and builds, regardless of the position of the eye box EB. In addition, in the case of content that does not overlap the foreground, such as ADAS status and warning icons, even for drivers of short stature, the display image is suppressed from entering the effective field of view, eliminating the problem of it being bothersome (intrusive).

[0031] Those skilled in the art will readily understand that the embodiments of the present invention illustrated can be further modified without departing from the spirit of the invention.

[0032] Figure 1 is a diagram showing an example of the application of a head-up display device according to an embodiment of the present invention to a vehicle. Figure 2 is a block diagram showing the configuration of an in-vehicle display system including a head-up display device according to an embodiment of the present invention. Figure 3A is a diagram showing the cross-sectional structure of a head-up display device according to an embodiment of the present invention, showing the rotation of the concave mirror when the eye box is in the reference position. Figure 3B is a diagram showing the cross-sectional structure of a head-up display device according to an embodiment of the present invention, showing the rotation of the concave mirror when the position of the eye box is changed. Figure 4 is a flowchart showing the basic processing procedure of a head-up display device according to an embodiment of the present invention. Figure 5A is a flowchart showing the detailed processing procedure of a head-up display device according to an embodiment of the present invention, showing the detailed processing procedure for "perspective adjustment of route guidance image". Figure 5B is a flowchart showing the detailed processing procedure of a head-up display device according to an embodiment of the present invention, showing the detailed procedure for "display position correction of route guidance image". Figure 6A is a diagram showing an example of a perspective image (virtual image) adjusted and displayed according to the position (depression angle) of the eye box by a head-up display device according to an embodiment of the present invention, showing the perspective image before and after countermeasures when the depression angle is higher than a predetermined angle reference value. Figure 6B shows an example of a perspective image (virtual image) that is adjusted and displayed according to the position (depression angle) of the eye box by a head-up display device according to an embodiment of the present invention, and shows the perspective image before and after the countermeasure when the depression angle is lower than a predetermined angle reference value. Figure 7 shows an example of a perspective image projected onto the virtual image forming surface (display area VA) by a head-up display device according to an embodiment of the present invention. Figure 8A shows an example of a perspective image (virtual image) whose display position is changed according to the position (depression angle) of the eye box by a head-up display device according to an embodiment of the present invention, and shows the display position when the depression angle is higher than a predetermined angle reference value.Figure 8B shows an example of a perspective image (virtual image) whose display position is changed according to the position (depression angle) of the eye box by a head-up display device according to an embodiment of the present invention, and shows the display position when the depression angle is lower than a predetermined angle reference value. Figure 9 shows an example of a perspective image (virtual image) whose display position is changed when projected onto the virtual image imaging surface (display area VA) by a head-up display device according to an embodiment of the present invention.

[0033] The best embodiments described below are used to facilitate understanding of the present invention. Therefore, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below (hereinafter referred to as "these embodiments").

[0034] (Configuration of the Embodiment) Refer to Figure 1. Figure 1 is a diagram showing an example of applying the head-up display device (hereinafter referred to as HUD device 100) of this embodiment to a vehicle CR.

[0035] As shown in Figure 1, the HUD device 100 displays a virtual image V by reflecting the display light L projected by the HUD device 100, which is a display device installed inside the instrument panel IP of the vehicle CR, back towards the driver DR, who is seated in the driver's seat inside the vehicle CR, via the windshield WS of the vehicle CR. Here, the HUD device 100 can display the virtual image V at any location within the virtual image forming surface (display area VA) that is virtually set up in front of the vehicle CR.

[0036] In other words, the HUD device 100 emits display light L from the liquid crystal display 120 (see Figure 2) of the image display unit 30 (see Figure 2), which will be described later, onto the windshield WS, which is the projection target, and allows the driver DR, who is the viewer, to see the display light L (virtual image V) obtained in response to this emission. As a result, the driver DR, who is the viewer, can see the virtual image V superimposed on the actual scenery in front of the vehicle CR.

[0037] In this case, the HUD device 100 projects a display light L that makes the virtual image V appear to be tilted at an angle of 45 degrees or less (0 to 45 degrees) relative to the road (road surface) on which the vehicle CR is traveling, with the upper part of the virtual image V appearing to be tilted further away from the driver, who is the viewer, than the lower part. As a result, the driver DR, who is the viewer, can see the virtual image V that is mainly superimposed on the road surface in front of the vehicle CR, and can obtain various information indicated by the content of that image.

[0038] Incidentally, the HUD device 100 is configured such that the eye box EB is the same as, or includes most of (for example, 80% or more of) the area where the driver DR's eye position (viewpoint position EP) in the height direction is assumed to be located (also called the eye lip). The "eye box EB" used in this embodiment refers to: (1) an area within which the entire virtual image V of the image displayed by the liquid crystal display 120 (see Figure 2) can be seen, and outside the area at least a portion of the virtual image V of the image cannot be seen; (2) an area within which at least a portion of the virtual image V of the image can be seen, and outside the area no portion of the virtual image V of the image can be seen; (3) an area within which at least a portion of the virtual image V of the image can be seen with a predetermined brightness or higher, and outside the area the entire virtual image V of the image is below the predetermined brightness; or (4) an area where, if the HUD device 100 is capable of displaying a stereoscopic virtual image V, at least a portion of the virtual image V can be seen stereoscopically, and outside the area no portion of the virtual image V can be seen stereoscopically. In other words, if the viewer (driver DR) positions their eyes (both eyes) outside the eye box EB, the viewer (driver DR) will not be able to see the entire virtual image V displayed by the liquid crystal display 120 (see Figure 2), the visibility of the entire virtual image V will be very low and difficult to perceive, or the virtual image V will not be visible in stereoscopic form. Here, the predetermined brightness is, for example, about 1 / 50 of the brightness of the virtual image V as seen at the center of the eye box EB.

[0039] Figure 2 is a block diagram showing an example configuration of an in-vehicle display system 1000 to which the HUD device 100 of this embodiment is applied.

[0040] As shown in Figure 2, the in-vehicle display system 1000 of this embodiment includes the HUD device 100, the viewpoint position detection device 301, the operation input device 302, and the vehicle monitoring device 303, all of which are connected to the in-vehicle LAN (Local Area Network) CAN (Control Area Network) 200 (I / O interface 400).

[0041] The HUD device 100 of this embodiment is a head-up display device that superimposes a real scene, which is the scenery in the forward field of view of the vehicle CR, and a generated virtual image V onto a virtual image forming surface (display area VA) that is virtually set up in front of the vehicle CR, and forms an image for the driver DR to view, and includes a control unit 10, a storage unit 20, and an image display unit 30.

[0042] The control unit 10 can vary the intensity of perspective adjustment that adds a sense of depth to the route guidance image according to the downward angle LD (see Figure 1), which is the angle formed by a virtual line VL parallel to the road surface from the driver DR's eye position (viewpoint position EP) in the height direction, and a straight line connecting the viewpoint position EP and the center of the virtual image forming surface (display area VA). It can also control the display of the perspective image generated by this perspective adjustment on the image display unit 30 (liquid crystal display 120). Here, "the driver DR's eye position in the height direction" refers to, for example, the driver DR's eye point EP (viewpoint position), as shown in Figure 1, and is detected, for example, by the viewpoint position detection device 301 shown in Figure 2. Furthermore, the virtual image V displayed by the HUD device 100 is correctly visible within a predetermined limited area (hereinafter also referred to as the eye box EB). Therefore, since the eye point EP of the driver DR, who is the viewer, can be presumed to be within the eye box EB, information regarding the driver DR's eye position in the height direction can be replaced by information regarding the position of the eye box EB. There is a correspondence between the position of the eye box EB and the position of the virtual image plane (display area VA) that is virtually set in front of the vehicle CR (when the eye box EB moves, the display area VA also moves accordingly), so the position of the eye box EB can be determined by the depression angle LD, which is the angle formed by the line connecting the driver DR's eye position in the height direction and the center of the virtual image plane (display area VA).

[0043] Furthermore, the downward angle LD can be estimated by performing image recognition based on an image of the driver's (DR) face, which is acquired by photographing the driver's (DR) face, or by detecting the setting position of the seat in which the driver (DR) is seated. In addition, as will be described later, the downward angle LD can also be estimated from the angle and / or position of an optical element (such as the concave mirror 141 of the imaging optical system 140) that is rotated by operating an operating member (operation input device 302).

[0044] Furthermore, "perspective adjustment" is an image processing technique that adds a sense of depth to an image using linear perspective (one-point perspective). For example, as shown in Figure 6 described later, when projecting a route guidance image (virtual image V) represented by arrow marks onto a virtual image forming surface (display area VA) virtually set in front of the vehicle CR, the position of vanishing points VP1 and VP2 is adjusted according to the position of the eye box EB to adjust the length of the arrow marks, resulting in a perspective image V. Ｔ , V Ｓ This refers to generating a (virtual image V). When creating an image using linear perspective and placing each object in the image at its respective depth position, a predetermined vanishing point VP ０ (See Figures 6A and 6B) Straight lines are virtually drawn radiating from the object, and by aligning the outlines of each object with these lines, each object is fixed and perceived at a predetermined depth position. The virtual image V, represented using linear perspective to be positioned parallel to the road surface, is a trapezoid, and using linear perspective, the intersection of the extension of the left side and the extension of the right side of the trapezoid corresponds to the intersection point (vanishing point VP) of the real scene (the lane in which the vehicle is traveling). ０ It is represented in a way that matches the ), thereby pictorially displaying the virtual image V as being positioned parallel to the surface (road surface) of the driving lane.

[0045] Furthermore, the control unit 10 can control the generation of a perspective image by varying the intensity of perspective adjustment, which adds a sense of depth to route guidance images, etc., based on the depression angle LD, which is adjusted by rotating the optical elements (concave mirrors 141 of the imaging optical systems 130, 140). The depression angle adjustment is performed by the driver DR, who is the viewer, operating the operation input device 302 to rotate the imaging optical systems 130, 140 (for example, the concave mirror 141), which are optical elements. The position of the eye box EB is determined by the direction of the display light L emitted from the HUD device 100 (for example, the position projected onto the window shield WS in Figure 1), and therefore changes according to the angle and / or position of the imaging optical systems 130, 140 (concave mirror 141), etc., within the HUD device 100 that determine the direction of the display light L emitted from the HUD device 100. Therefore, information regarding the position of the eye box EB (information regarding the height position of the driver DR's eye) can be replaced by information regarding the angle and / or position of the imaging optical systems 130, 140 (concave mirror 141). Thus, for example, as shown in Figure 1, the depression angle LD, which is the angle formed by the line connecting the height position of the driver DR's eye (eye point EP) and the center of the virtual image plane (display area VA), can be determined by the angle and / or position of the imaging optical systems 130, 140 (concave mirror 141).

[0046] For example, as shown in Figure 3, in the HUD device 100, the concave mirror 141 is connected to the drive unit 110. The drive unit 110, under the control of the control unit 10, can rotate the concave mirror 141 within a predetermined angular range based on the eye position (eye point EP) in the height direction of the viewer, the driver DR, which is set by the viewer, or detected by the viewpoint position detection device 301. This allows the point at which the display light L reaches within the windshield WS to be changed. In other words, the position of the virtual image imaging surface (display area VA) on which the virtual image V is placed can be changed in accordance with the change in the depression angle LD (position of the eye box EB).

[0047] Furthermore, the control unit 10 determines that the depression angle LD is a predetermined angle reference value LD ＴＨIf the value is smaller, control is performed to weaken the intensity of perspective adjustment for route guidance images represented by arrow marks, etc., and the downward angle LD is set to a predetermined angle reference value LD. ＴＨ If it is greater, control can be performed to increase the intensity of perspective adjustment for the route guidance image, which is also represented by arrow marks, etc. Here, "a predetermined angle reference value LD ＴＨ " is a value determined by the specifications of the head-up display device through verification (experiments and simulations), for example, the angle reference value LD obtained from verification results when the field of view is 10° × 3° and the image plane distance is 10 [m]. ＴＨ This is pre-stored in a predetermined area of ​​the memory unit 20.

[0048] For example, the depression angle LD is a predetermined angle reference value LD ＴＨ For taller, relatively taller viewers (driver DR) (for example, the "Taller" shown in Figure 6A), the control unit 10 displays the route guidance image, represented by arrow marks, lower down (before countermeasures were implemented), so the vanishing point of the route guidance image is moved towards the back (upward VP). １ By adjusting the perspective in the direction of (), the length of the arrow is increased in the perspective image V. Ｔ (After countermeasures) is generated and controlled to be displayed on the image display unit 30. On the other hand, as shown in Figure 6B, when the position of the eye box EB is lowered due to the height of the viewer (driver DR) (in the case of a viewer with a short stature "Shorter"), the control unit 10 controls the vanishing point of the route guidance image, which is represented by an arrow mark, to be moved upwards (before countermeasures), because the vanishing point of the route guidance image is moved to the front side (downward VP ２ Perspective image V with the arrow length shortened in the direction of ). Ｓ The system can generate (after countermeasures) and control the image display unit 30 to display it.

[0049] Furthermore, the control unit 10 determines that the depression angle LD is a predetermined angle reference value LD ＴＨ If smaller, perspective image V Ｔ The control is performed to change the display position downward by a predetermined amount, and the depression angle LD is set to a predetermined angle reference value LD. ＴＨ If larger, perspective image V ＳThe display position can be controlled to be moved upward by a predetermined amount. Here, "determined amount" refers to the perspective image V in the virtual image plane (display area VA) optimized for each depression angle LD (position of eye box EB). Ｔ , V Ｓ This refers to the amount of movement of the display position (the display position of the virtual image V on the virtual image forming surface (display area VA) where the angle and / or position of the rotationally driven optical element (concave mirror 141) have been adjusted), and is a value determined by the verification described above, and is a value that is pre-stored in a predetermined area of ​​the storage unit 20.

[0050] For example, as shown in Figure 8A, when the position of the eyebox EB (depression angle LD) is "Taller", the perspective image V is different compared to the "Normal" position. Ｔ Because the (virtual image V) is displayed lower, the perspective image V is positioned a predetermined amount above the virtual image plane (display area VA). Ｔ The display position is changed to position (virtual image V), while on the other hand, for example, as shown in Figure 8B, when the position of the eye box EB (downward angle LD) is "Shorter", the perspective image V is different compared to the "Normal" position. Ｓ Because the (virtual image V) is displayed above, the perspective image V is lowered by a predetermined amount on the virtual image plane (display area VA). Ｓ Control is performed to change the display position so that (virtual image V) is positioned.

[0051] The control unit 10 includes, for example, a processor with built-in or external memory (ROM / RAM), and a graphics controller that draws images generated by the processor onto VRAM (Video RAM) allocated to a predetermined area of ​​RAM, and displays them on the image display unit 30 (liquid crystal display 120) according to the display timing. The processor executes each of the above-mentioned functions by running a program recorded in ROM. Furthermore, at least some of the above-mentioned functions can be realized by hardware such as FPGA (Field Programmable Gate Array) or logic circuits, rather than by a processor.

[0052] The memory unit 20 is a memory in which a program area and a work area are allocated, and for example, static RAM, dynamic RAM, or flash memory is implemented. Here, various programs such as the display control program necessary to control the HUD device 100 of this embodiment are written in the program area, and the work area contains information generated during the execution process of the above-mentioned programs, route guidance information acquired from the navigation device 200 (route guidance start information, route guidance end information, direction information, etc.), and a predetermined angular reference value LD of the downward angle LD (position of the eye box EB) which is determined depending on the height of the driver DR who is the viewer. ＴＨ These are assigned and written to.

[0053] The image display unit 30 includes a liquid crystal display 120, imaging optical systems 130 and 140 (see Figures 3A and 3B) including a concave mirror 141, and a drive unit 110 for displaying the virtual image V generated by the control unit 10.

[0054] The liquid crystal display 120 mainly consists of a light source 121, which is made up of light-emitting diodes mounted on a wiring board, as shown in Figures 3A and 3B, and a TFT (Thin Film Transistor Liquid Crystal) type liquid crystal display element 122, which is located on the emission side (directly above) of the light source 121 so as to transmit illumination light from the light source 121 and form display light L. This means that the light source 121 is provided behind the liquid crystal display element 122, and the liquid crystal display element 122 displays a predetermined image (virtual image V) using the light emitted from the light source 121.

[0055] Furthermore, the liquid crystal display 120 has a display surface 120a arranged diagonally with respect to the optical axis, as shown in Figures 3A and 3B, and outputs display light L consisting of light in the visible wavelength range. For example, a light source 121 that emits white light can be applied, and the liquid crystal display element 122 transmits the light emitted from this light source 121 to output display light L containing the desired image. The liquid crystal display element 122 forms the desired image based on the display image data (drive signal) generated by the drawing calculation by the control unit 10. For example, the liquid crystal display element 122 displays images (virtual images V) generated by the control unit 10, such as numerical values ​​and icons, for example, the vehicle CR's speed, remaining energy, time, and route guidance images. Note that not only vehicle information such as the vehicle CR's speed and remaining energy, but any display format can be adopted.

[0056] The imaging optical systems 130 and 140, as shown in Figures 3A and 3B, for example, are composed of a plurality of reflectors including a concave mirror 141 which is an optical element (reflective element), and project the display light L generated by the liquid crystal display 120 onto the windshield shield WS, which is the projection target, through an opening window 152 provided at the top of the HUD device 100. Details of the imaging optical systems 130 and 140 will be described later with reference to Figures 3A and 3B. The drive unit 110 is connected to the concave mirror 141, which is an optical element (reflective element), and can rotate the concave mirror 141 to a predetermined angular position based on a control signal generated by the control unit 10. The rotation position of the concave mirror 141 has several steps and can be adjusted within that range. The concave mirror 141 uses a stepping motor to drive its rotation and can be rotated by a predetermined number of steps corresponding to the position (setting information) of the eye box EB set by the operation of the operation input device 302.

[0057] On the other hand, looking at the peripheral configuration of the HUD device 100 in this embodiment, it includes a navigation device 200, a viewpoint position detection device 301, an operation input device 302, and a vehicle monitoring device 303. Furthermore, each of these devices 200, 301, 302, and 303 is connected to the I / O interface 400 via an ECU (electronic control unit), which is not shown. The ECU also mainly controls the drive system, braking system, and steering system of the vehicle CR.

[0058] The navigation device 200 provides route guidance to the destination according to GPS (Global Positioning System) and pre-entered route information. The eye position detection device 301 is a system that monitors the driver's (DR) driving status using an in-vehicle camera included in the vehicle monitoring device 303, such as the DMS (Driver Status Monitor), with the aim of preventing dangerous driving and accidents. Here, it is also used in combination with facial recognition (image recognition) to detect the eye position (eye point EP) of the driver (DR), who is the observer.

[0059] The operation input device 302 is, for example, a set of switches located near the steering wheel. By operating these switches, the driver DR, who is the observer, can switch the HUD device 100 ON / OFF, set the airflow of the air conditioner, and further set setting information (such as the position of the eye box EB) that instructs the rotational movement of the optical element (see the concave mirror 141 shown in Figures 3A and 3B) by the drive unit 110 of the HUD device 100.

[0060] The vehicle monitoring device 303 consists of sensors necessary for recognizing the surrounding driving environment, including the area in front of the vehicle CR, and includes cameras, LiDAR (Light Detection and Ranging), etc. It also includes an IMU (Inertial Measurement Unit), vehicle speed sensor, seat sensor, etc., for detecting the behavior of the vehicle CR. Information recognized or detected by the vehicle monitoring device 303 is transferred to the HUD device 100 of this embodiment via the I / O interface 400.

[0061] In addition to an external camera that captures the forward view (real scenery) of the vehicle CR, the system also has an internal camera that captures the face of the driver DR, who is the observer, and outputs the image to the viewpoint position detection device 301 for facial recognition (in this case, detection of the viewpoint position in the direction of the driver DR's eyes). The LiDAR uses near-infrared light, visible light, and ultraviolet light to illuminate obstacles, for example, that are in front of the vehicle CR as captured by the external camera, and the reflected light is captured by an optical sensor, and the distance to the obstacle is determined by the time difference. The IMU uses a 3-axis acceleration sensor and a 3-axis angular velocity sensor (gyro sensor) to measure the driving conditions and attitude of the vehicle CR (accelerometer [m / s²]). ２ It can detect translational motion in the three axes from the angle [deg / s] and rotational motion from the angular velocity [deg / s]. In addition, the seat sensor can detect the set position of the seat in which the driver DR, who is the observer, is seated.

[0062] The I / O interface 400 communicates (also referred to as CAN communication) with the navigation device 200, viewpoint position detection device 301, operation input device 302, and vehicle monitoring device 303 via an ECU (not shown) located in the vehicle CR, in addition to the display control device 300, according to the CAN (Controller Area Network) standard. Furthermore, the communication standards adopted by the I / O interface 400 are not limited to CAN, but include, for example, wired communication interfaces such as CANFD (CAN with FlexEBLE Data Rate), LIN (Local Interconnect Network), Ethernet®, MOST (Media Oriented Systems Transport: MOST is a registered trademark), UART (Universal Asynchronous Receiver Transmitter), or USB (Universal Serial Bus), or in-vehicle communication (internal communication) interfaces, which are short-range wireless communication interfaces within tens of meters, such as personal area networks (PANs) such as Bluetooth® networks, and local area networks (LANs) such as 802.11x Wi-Fi® networks.

[0063] Furthermore, the I / O interface 400 may also include an external communication interface such as a wide-area communication network (e.g., an Internet communication network) based on cellular communication standards such as wireless wide-area networks (WWAN0, IEEE 802.16-2004 (WiMAX: Worldwide Interoperability for Microwave Access)), IEEE 802.16e-based (Mobile WiMAX), 4G, 4G-LTE, LTE Advanced, and 5G.

[0064] Figure 3 shows the cross-sectional structure of the HUD device 100 of this embodiment. Figure 3A shows the rotation of the optical element (concave mirror 141) when the eye box EB is in the reference position, and Figures 3A and 3B show the rotation of the optical element (concave mirror 141) when the position of the eye box EB is changed.

[0065] According to Figures 3A and 3B, the HUD device 100 mainly consists of a liquid crystal display 120, a first reflector which is an imaging optical system 130, a second reflector which is an imaging optical system 140, and a housing 150. As described above, the liquid crystal display 120 has a display surface 120a and outputs display light L consisting of light in the visible wavelength range. For example, a light source 121 that emits white light can be applied, and the liquid crystal display element 122 transmits the light emitted from this light source 121 to output display light L containing a desired image.

[0066] The first reflector (imaging optical system 130) is equipped with a cold mirror 131. The cold mirror 131 reflects light in the visible wavelength range (450 to 750 nm), which includes the emission wavelength range of the liquid crystal display 120, with a high reflectivity of, for example, 80% or more, and reflects light outside the visible wavelength range with a low reflectivity. In this case, the cold mirror 131 is one that reflects light outside the visible wavelength range, especially in the infrared wavelength range (heat rays from sunlight and other external light), with a low reflectivity of, for example, 15% or less. Light that is not reflected by the reflective layer of the cold mirror 131 is configured to pass through the cold mirror 131. The cold mirror 131 prevents the liquid crystal display element 122 from being heated to a high temperature by sunlight or the like.

[0067] The second reflector (imaging optical system 140) includes a concave mirror 141 that reflects the display light L from the cold mirror 131 (i.e., the liquid crystal display element 122), and a mirror holder 142 that holds the concave mirror 141.

[0068] The concave mirror 141 has a second reflective layer 141a deposited on a resin substrate made of polycarbonate having a concave surface. The concave mirror 141 is positioned at an angle so that its second reflective layer 141a faces the cold mirror 131 and the translucent cover 153, and is visible from the translucent cover 153.

[0069] The concave mirror 141 magnifies the display light L from the cold mirror 131 and reflects (projects) it toward the translucent cover 153 (the windshield WS of the vehicle CR). This means that the concave mirror 141 magnifies the display light L reflected by the cold mirror 131 and projects this magnified display light L onto the windshield WS through the translucent cover 153. The concave mirror 141 is attached to the mirror holder 142 by a double-sided adhesive material. The mirror holder 142 is made of a synthetic resin such as ABS (Acrylonitrile Butadiene Styrene) and is fixed to the housing 150.

[0070] The concave mirror 141 is connected to the drive unit 110 and can be rotated within a predetermined angular range depending on the situation. This allows the point at which the display light L reaches within the windshield WS to be changed. In other words, the position of the eye box EB of the HUD device 100 changes. From this, the height of the eye (eye point EP) at which the viewer, the driver DR, can see the image, and the display position within the virtual image plane (display area VA) where the image is displayed can be changed.

[0071] Here, as the position of the eye box EB decreases, the display position of the image (virtual image V) within the virtual image plane (display area VA) increases. This means that the depression angle LD, which is the angle between two lines—a straight line parallel to the road surface (virtual line VL) based on the height of the driver DR's eye position (eye point EP) and the straight line connecting the height of the viewer 14's eye position (eye point EP) and the center of the virtual image plane (display area VA)—changes in a direction that decreases. On the other hand, as the position of the eye box EB increases, the display position of the image within the virtual image plane (display area VA) decreases. This means that the downward angle LD (see Figure 1), which is the angle between two lines—a straight line parallel to the road surface (virtual line VL) based on the eye position (eye point EP) of the driver DR in the height direction, and a straight line connecting the eye position (eye point EP) of the driver DR in the height direction and the center of the virtual image plane (display area VA)—changes in the direction of increasing size.

[0072] In other words, when the concave mirror 141, which is in the reference position shown in Figure 3A, rotates clockwise, the position of the eye box EB rises as shown in Figures 3A and 3B, and conversely, when it rotates counterclockwise, the position of the eye box EB falls lower. Since the depression angle LD is uniquely determined by a predetermined calculation formula based on the position of the eye box EB, calculating the display position of the image using the position of the eye box EB is equivalent to calculating the display position of the image on the virtual image plane (display area VA) using the depression angle LD.

[0073] The housing 150 is made of, for example, a black light-shielding synthetic resin material and is formed in a roughly box shape. It holds and houses the projection unit consisting of a liquid crystal display 120, a first reflector (imaging optical system 130), and a second reflector (imaging optical system 140) in its internal space 151. The housing 150 has an opening window 152 through which the upper part (windshield WS side) of the concave mirror 141 in the second reflector (imaging optical system 140) opens. The housing 150 is also provided with a light-transmitting cover 153, which is an output part, so as to close the opening window 152. This light-transmitting cover 153 is made of a light-transmitting synthetic resin material (for example, acrylic resin), is formed in a curved shape (curved surface shape), and functions as a light-transmitting member through which the display light L reflected by the concave mirror 141 is transmitted (passed). In other words, the display light L reflected by the cold mirror 131 and the concave mirror 141, that is, the display light L output by the projection unit, is projected onto the windshield WS, which is the projection target, through the translucent cover 153 formed in the housing 150, thereby displaying the virtual image V.

[0074] In this embodiment, the HUD device 100 projects the image (virtual image V) displayed on the display surface 120a of the liquid crystal display 120 of the image display unit 30 to the lower side of the windshield WS, which is the projection target. Therefore, from the perspective of the driver DR, who is the viewer, the virtual image V can be observed superimposed on the foreground, which is the scenery in front of the vehicle CR, from the lower area of ​​the windshield WS. Consequently, the driver DR, who is the viewer, will mainly see the virtual image V displayed on the road surface near the vehicle CR. Furthermore, due to the configuration of the projection unit of the HUD device 100 in this embodiment, the outputted virtual image V appears tilted so that the upper part of the image is further away from the vehicle CR than the lower part.

[0075] (Operation of the Embodiment) The operation of the HUD device 100 of this embodiment shown in Figures 1 to 3 will be described in detail below with reference to Figures 4 to 9. Figure 4 is a flowchart showing the basic processing procedure of the HUD device 100 according to this embodiment, Figure 5A is a flowchart showing the detailed processing procedure of "perspective adjustment of route guidance image" shown in Figure 4, and Figures 53A and 53B are flowcharts showing the detailed procedure of "display position correction of route guidance image".

[0076] Furthermore, Figure 6 shows an example of a perspective image that is adjusted and displayed according to the position (depression angle LD) of the eye box EB by the HUD device 100 of this embodiment, and Figure 6A shows that the depression angle LD is a predetermined angle reference value LD ＴＨ If it is higher, Figures 6, 3A and 3B show that the depression angle LD is a predetermined angle reference value LD. ＴＨ Perspective image V before and after countermeasures in the case of lower levels Ｔ , V Ｓ Figure 7 shows each of these. Also, Figure 7 shows the perspective image V projected onto the virtual image forming surface (display area VA) by the HUD device 100 of this embodiment. Ｔ , V Ｎ , V Ｓ This is an example shown in the figure.

[0077] Furthermore, Figure 8 shows an example of a perspective image in which the display position is changed according to the position (depression angle LD) of the eye box EB by the HUD device 100 of this embodiment, and Figure 8A shows that the depression angle LD is a predetermined angle reference value LD ＴＨ Figures 8, 3A, and 3B show the display position when the depression angle LD is a predetermined angle reference value LD. ＴＨ Figure 9 shows the display position when it is lower. Also, Figure 9 shows the perspective image V with a changed display position projected onto the virtual image forming surface (display area VA) by the HUD device 100 of this embodiment. Ｔ , V Ｎ , V Ｓ This figure shows an example of (virtual image V).

[0078] In Figure 4, the HUD device 100 of this embodiment has a control unit 10 that first acquires navigation information from the navigation device 200 (step ST101). When the control unit 10 obtains the route guidance start information included in the navigation information, it generates a route guidance image, represented by arrow marks as shown in Figures 6A, 3A, and 3B, according to the direction information also included in the navigation information (step ST102).

[0079] Next, the control unit 10 acquires information regarding the height-direction eye position (eye point EP) of the driver DR, who is the viewer, detected by image processing using the viewpoint position detection device 301 (step ST103). From the height-direction eye position (eye point EP) of the driver DR, the control unit 10 performs calculations to estimate the depression angle LD (position of the eye box EB), which is the angle formed by a straight line parallel to the road surface (virtual line VL) and a straight line connecting the driver DR's eye point EP and the center of the route guidance image (virtual image V) (step ST104). The depression angle LD (position of the eye box EB) can also be estimated by the rotation angle and / or position of the concave mirror 141 obtained by rotating the concave mirror 141 of the imaging optical systems 130, 140, as shown in Figure 2, or Figures 3A and 3B, by the driver DR, who is the viewer, operating the operation input device 302. That is, the rotation angle and / or position of the concave mirror 141 corresponds one-to-one with the depression angle LD.

[0080] Next, the control unit 10 determines the depression angle LD generated by the estimation calculation and the depression angle LD and a predetermined angle reference value LD. ＴＨ A comparison was made, and the downward angle LD (position of eye box EB) was found to be a predetermined angle reference value LD. ＴＨ Determine whether it is smaller or not (step ST105). Here, the predetermined angle reference value LD of the depression angle LD ＴＨ This refers to the downward angle LD of the driver DR, who is a viewer with a standard height, and is a value that is stored in advance in a predetermined area of ​​the memory unit 20. Here, the downward angle LD is a predetermined angle reference value LD. ＴＨ If it is smaller (step ST105 "YES"), the control unit 10 adjusts the perspective of the route guidance image and creates a perspective image V with reduced (weakened) perspective intensity. Ｔ(A virtual image V) is generated (step ST106). Meanwhile, the depression angle LD is a predetermined angle reference value LD ＴＨ If it is larger (step ST105 "NO"), the control unit 10 adjusts the perspective of the route guidance image and produces a perspective image V with enhanced perspective. Ｓ (A virtual image V) is generated (step ST107).

[0081] The detailed procedure for adjusting the perspective of the route guidance image (virtual image V) is shown in Figure 5A, and an example of a perspective image that is adjusted and generated according to the depression angle LD (position of eye box EB) is shown in Figure 6 (Figure 6A: when the depression angle LD is a predetermined angle reference value LD ＴＨ Perspective image V before and after countermeasures in the case of higher levels Ｔ Figures 6, 3A, and 3B: The depression angle LD is set to a predetermined angle reference value LD. ＴＨ Perspective image V before and after countermeasures in the case of lower levels Ｓ ) is shown.

[0082] Referring to the flowchart shown in Figure 5A, the control unit 10 first determines the position of the eye box EB based on the depression angle LD (step ST201). For example, if the depression angle LD (position of the eye box EB) is a predetermined angular reference value LD ＴＨ For taller, relatively taller viewers (step ST201 "Taller"), for example, as shown in Figure 6A, the route guidance image is displayed lower than the normal eye box EB position ("Normal"), so the vanishing point VP １ The perspective is adjusted to point the image more upwards (step ST202), for example, the length of the arrow in the route guidance image, represented by an arrow mark, is made longer (approximately 0.85 times that of "Normal"), resulting in a perspective image V. Ｔ (Virtual image V) is generated (after countermeasures are taken) (step ST203).

[0083] On the other hand, the downward angle LD (position of eye box EB) is a predetermined angular reference value LD ＴＨFor smaller, relatively shorter viewers (step ST201 "Shorter"), for example, as shown in Figures 63A and 3B, the position of the eye box EB is such that the route guidance image is displayed higher than in "Normal" (before countermeasures), so the vanishing point VP ２ The perspective is adjusted to point more downwards (step ST204), for example, shortening the length of the arrows in the route guidance image represented by arrow marks (to about 1.15 times compared to "Normal") to create a perspective image V. Ｓ (Virtual image V) is generated (after countermeasures are taken) (step ST205).

[0084] Furthermore, if the position of the eyebox EB is between "Taller-Normal" and "Shorter-Normal," the length of the arrow shall be the length calculated by linear interpolation. The aforementioned values ​​of 0.85 and 1.15 are calculated based on the design values ​​of a HUD device 100, which is superimposed on the foreground of the vehicle CR's forward view, for example, with a field of view of 10° × 5° and an image plane distance of 10 [m], so that the virtual image (V) has the same perspective as the forward tilt. Finally, the control unit 10 outputs the generated perspective image (V Ｔ , V Ｓ The system controls the display of the image superimposed on the foreground on a virtual image-forming surface (display area VA) virtually set up in front of the vehicle CR.

[0085] Figure 7 shows the perspective image (V) projected onto the virtual image forming surface (display area VA) by the HUD device 100 of this embodiment. Ｔ , V Ｎ , V Ｓ An example of this is shown. As shown in Figure 7, when the driver DR, who is the viewer, is relatively tall, and the position of the eye box EB is "Taller", the length of the route guidance image (virtual image V) represented by arrows, etc. is the same as the perspective image V in the case of "Normal", where the eye box EB is at the position of a viewer (driver DR) with a standard height. Ｎ Perspective image V, which appears longer and sticks to the road surface. Ｔis projected and displayed on a virtual image formation surface (display area VA) that is virtually set in front of the vehicle CR. On the other hand, when the height of the driver DR who is the viewer is relatively low and the position of the instrument panel EB is "Shorter", the perspective image V in the case of "Normal", which is the position of the instrument panel EB of a driver with a standard height Ｎ is shorter than that in the case of Ｓ and the perspective image V is visually recognized as floating above the road surface and is projected and displayed on a virtual image formation surface (display area VA) that is virtually set in front of the vehicle CR.

[0086] Returning the explanation to the flowchart of FIG. 4. After the perspective adjustment of the route guidance image, the control unit 10 determines whether there is a change in the position of the instrument panel EB by the depression angle adjustment (step ST108). If there is a change in the angle and / or position of the optical member (concave mirror 141 of the imaging optical systems 130 and 140) that is rotationally driven when the driver DR who is the viewer operates the operation input device 302 (step ST108 "YES"), the processes of steps ST104 to ST107 are repeatedly executed. If there is no change in the position of the instrument panel EB by the depression angle adjustment in step ST108 (step ST108 "NO"), the control unit 10 corrects the display position (display coordinates) of the perspective image V Ｔ , V Ｓ (step ST109).

[0087] The detailed procedure for correcting the display position (display coordinates) of the perspective image is shown in FIGS. 5, 3A, and 3B. A perspective image (V Ｔ , V Ｎ , V Ｓ ) whose display position is changed according to the depression angle LD (position of the instrument panel EB) is shown in FIG. 8 (FIG. 8A shows the display position when the depression angle LD is higher than a predetermined angle reference value LD ＴＨ , and FIGS. 8, 3A, and 3B show the display position when the depression angle LD is lower than a predetermined angle reference value LD ＴＨ ).

[0088] Referring to the flowcharts shown in FIGS. 5, 3A, and 3B, the control unit 10 first determines the position of the instrument box EB based on the depression angle LD (step ST301). For example, when the depression angle LD is greater than a predetermined angle reference value LD ＴＨ for a relatively tall viewer (driver DR) (step ST301 “Taller”), for example, as shown in FIG. 8A, when the position of the instrument box EB is “Normal”, the perspective image V Ｔ is displayed lower, so the control changes the display position so that the perspective image V Ｔ is arranged higher in the virtual image formation plane (display area VA) (step ST302). On the other hand, when the depression angle LD is smaller than a predetermined angle reference value LD ＴＨ for a relatively short viewer (driver DR) (step ST301 “Shorter”), for example, as shown in FIGS. 8, 3A, and 3B, when the position of the instrument box EB is “Normal”, the perspective image V Ｓ is displayed higher, so the control changes the display position so that the perspective image V Ｓ is arranged lower in the virtual image formation plane (display area VA) (step ST303).

[0089] Specifically, the control unit 10 changes the rendering position (camera position for rendering) of the 3D model used for display according to the position of the instrument box EB. If the position of the instrument box EB is at the “Taller” position, the perspective image V Ｔ rendered from the position corresponding to “Taller” is displayed on the image display unit 30. If the position is at the “Shorter” position, the perspective image V Ｓ rendered from the position corresponding to “Shorter” is displayed on the image display unit 30. In this way, when the depression angle LD is smaller than a predetermined angle reference value LD ＴＨ , the control unit 10 controls to change the display position of the perspective image V Ｔ downward by a predetermined amount. When the depression angle LD is greater than a predetermined angle reference value LD ＴＨ , the control unit 10 controls to change the display position of the perspective image V ＳThe display position of the virtual image can be controlled to be moved upward by a predetermined amount. Here, "determined amount" refers to the amount of movement of the display position of the virtual image V in the virtual image imaging plane (display area VA) optimized for each depression angle LD (position of the eye box EB) (the display position of the virtual image V in the display area VA in which the angle and / or position of the rotationally driven optical element (concave mirror 141 shown in Figures 2, 3A, and 3B) has been adjusted), which is a value determined by verification and is a value that has been stored in advance in a predetermined area of ​​the storage unit 20 shown in Figure 2.

[0090] Figure 9 shows the perspective image V projected onto the virtual image forming surface (display area VA) by the HUD device 100 of this embodiment. Ｔ , V Ｎ , V Ｓ An example is shown. As shown in Figure 9, when the driver DR, who is the viewer, is relatively tall, and the position of the eye box EB is "Taller", the perspective-adjusted perspective image V Ｔ This is the perspective image V when the position of eyebox EB is "Normal". Ｎ Compared to the other configuration, when the eyebox EB is positioned above the virtual image plane (display area VA) and the driver DR (viewer) is relatively short, the perspective-adjusted and generated perspective image V S This is the perspective image V when the position of eyebox EB is "Normal". Ｎ It is positioned below the virtual image forming surface (display area VA).

[0091] Thus, the perspective image V, which is the foreground and virtual image V, is independent of the position of the eye box EB. Ｔ Or V Ｓ This allows for the maintenance of a relationship with the driver DR, who may have different physical characteristics, and provides a HUD device 100 that can give the same impression to the driver DR (who may have different physical characteristics) (it can display the virtual image V as if it were located at the target position in the foreground).

[0092] Return to the flowchart in Figure 4 for explanation. Perspective Image V Ｔ , V ＳAfter the display position (display coordinate) correction process, the control unit 10 processes the perspective image V, which has undergone perspective adjustment and whose display position has been changed. Ｔ , V Ｎ , V Ｓ The image is superimposed on the foreground of the vehicle CR's forward view and displayed on the image display unit 30 (liquid crystal display 120) (step ST110). Then, when route guidance information (route guidance completion information) is obtained from the navigation device 200 (step ST111 "YES"), the control unit 10 displays the perspective image V, which is the route guidance display. Ｔ , V Ｎ , V Ｓ The process is controlled to hide the element (step ST112), and the series of processes described above is terminated.

[0093] Furthermore, the flowcharts shown in Figures 4, 5A, 3A, and 3B do not limit the processing procedures according to the present invention to those shown in the flowcharts, and additional procedures may be added, deleted, or the order changed without departing from the spirit and technical idea of ​​the invention. In addition, although the HUD device 100 of this embodiment has been described as an example of performing perspective adjustment on a route guidance image represented by arrow marks, when performing perspective adjustment on a route guidance image represented by something other than arrow marks, or on an object different from a route guidance image, in addition to changing the size of the virtual image V by controlling the vanishing point, the target image can also be emphasized by changing the brightness, density, color tone, etc., according to the display distance or the size of the object, or by applying image processing such as shading, overlapping, or blurring.

[0094] (Effects of the Embodiment) As described above, the head-up display device of this embodiment is a HUD device 100 that superimposes the foreground in the forward field of view of the vehicle CR and one or more virtual images V onto a virtual image forming surface (display area VA) virtually set in front of the vehicle CR, as shown in Figure 1, and allows a viewer (driver DR) riding in the vehicle CR to view it. The HUD device 100, as shown in Figure 2, for example, includes an image display unit 30 that displays a route guidance image and a control unit 10 that performs perspective adjustment to give the route guidance image a sense of depth. The control unit 10 varies the intensity of the perspective adjustment that gives the route guidance image a sense of depth according to the downward angle LD, which is the angle formed by a straight line parallel to the road surface (virtual line VL) from the viewer's eye position in the height direction (eye point EP) and a straight line connecting the viewer's eye position in the height direction (eye point EP) and the center of the virtual image forming surface (display area VA). The control unit 10 then controls the display of the virtual image generated by the perspective adjustment on the image display unit 30.

[0095] According to the HUD device 100 of this embodiment, the control unit 10 controls the intensity of perspective adjustment for the route guidance image (virtual image V), which is represented by an arrow mark, according to the downward angle LD (position of the eye box EB), and displays the generated perspective image on the image display unit 30. In this way, the control unit changes the intensity of perspective adjustment to the route guidance image according to the downward angle (position of the eyebox). For example, for relatively tall viewers, the perspective adjustment is weakened by moving the vanishing point of the route guidance image, represented by an arrow mark, towards the back (upwards), thereby generating a perspective image with a longer arrow. On the other hand, for relatively short viewers, the perspective adjustment is strengthened by moving the vanishing point of the route guidance image towards the front (downwards), thereby generating a perspective image with a shorter arrow and displaying it on the image display unit. By doing so, depending on the downward angle (position of the eyebox), the route guidance image (virtual image) indicating a point to turn at an intersection, for example, does not give the impression that it is pointing to a different point than the point to turn, and the relationship between the foreground and the virtual image V is perceived differently depending on the viewer's height and build.

[0096] Therefore, the displayed image (in this case, the route guidance image represented by an arrow mark displayed as a virtual image V) is displayed at the target position in the foreground, regardless of the downward angle (position of the eye box EB), providing a head-up display device that can give the same impression to drivers who are viewers of different heights and builds. Furthermore, in the case of content that does not superimpose on the foreground, such as ADAS status and warning icons, the display image is suppressed from entering the effective field of view, especially for viewers of short stature, thus eliminating the feeling of annoyance (intrusion).

[0097] Furthermore, according to the HUD device 100 of this embodiment, the control unit 10 controls the intensity of perspective adjustment based on the downward angle LD (position of the eye box EB), which is adjusted by rotating an optical element (for example, the concave mirror 141 of the imaging optical systems 130 and 140 shown in Figures 2, 3A, and 3B). Therefore, for example, without relying on the viewpoint position detection device 301 shown in Figure 2, the estimated position of the eye box EB does not give the impression that it is pointing to a different location than where one should turn, such as an intersection, and the relationship between the foreground and the virtual image is perceived differently depending on the viewer's build. As a result, the displayed image (here, the route guidance image represented by an arrow mark displayed as a virtual image V) can give the same impression to viewers with different builds, regardless of the downward angle LD (position of the eye box EB).

[0098] Furthermore, according to the HUD device 100 of this embodiment, the control unit 10 determines that the depression angle LD is a predetermined angle reference value LD ＴＨ If the value is smaller, control is applied to reduce the intensity of perspective adjustment, and the depression angle LD is set to a predetermined angle reference value LD. ＴＨBy controlling the intensity of perspective adjustment when the angle is larger, the displayed image (in this case, the route guidance image represented by an arrow mark displayed as a virtual image V) does not give the impression of pointing to a different location than where one should turn, for example, at an intersection, depending on the downward angle LD (position of the eye box EB). This eliminates the problem of the relationship between the foreground and the virtual image being perceived differently depending on the viewer's build. Therefore, the displayed image can give the same impression to viewers with different builds, regardless of the downward angle (position of the eye box).

[0099] Furthermore, according to the HUD device 100 of this embodiment, the control unit 10 determines that the depression angle LD is a predetermined angle reference value LD ＴＨ If smaller, perspective image V Ｔ The control is performed to move the display position downward by a predetermined amount, and the depression angle LD is set to a predetermined angle reference value LD. ＴＨ If larger, perspective image V Ｓ By controlling the display position of the foreground and the virtual image V, the perspective image V is displayed, regardless of the position of the eye box EB, and the foreground and virtual image V are displayed. Ｔ Or V Ｓ This allows for maintaining a relationship with the target and giving the same impression to viewers with different physical characteristics (making it appear as if the virtual image is located at the target position in the foreground).

[0100] The control method for the head-up display device of this embodiment is a control method for a HUD device 100 which includes, for example, an image display unit 30 that displays a route guidance image for viewing by a viewer (driver DR) in the vehicle CR by superimposing the foreground in the forward field of view of the vehicle CR and one or more virtual images V onto a virtual image forming surface (display area VA) that is virtually set in front of the vehicle CR, as shown in Figures 1 and 2; an optical member (concave mirror 141 of the imaging optical system 130, 140) having a curved reflective surface that projects the route guidance image onto the virtual image forming surface (display area VA); and a control unit 10 that controls the rotational drive of the image display unit 30 and the optical member to perform perspective adjustment to give a sense of depth to the route guidance image. The control method, as shown in Figure 4, for example, is a control method for a head-up display device that includes the steps of: (ST101 to ST104) estimating the depression angle LD, which is the angle formed by a straight line (virtual line VL) parallel to the road surface from the eye position (eye point EP) in the height direction of the viewer and a straight line connecting the eye position (eye point EP) in the height direction of the viewer and the center of the virtual image forming surface (display area VA), and (ST105 to ST112) controlling the control unit 10 to vary the intensity of the perspective adjustment performed on the route guidance image (virtual image V) according to the estimated depression angle LD, and to display the virtual image V generated by the perspective adjustment on the image display unit 30.

[0101] According to the control method of the head-up display device (HUD device 100) of this embodiment, the control unit 10 changes the intensity of perspective adjustment for the route guidance image (virtual image V) according to the estimated downward angle LD (position of the eye box EB). For example, for a relatively tall viewer, the perspective adjustment is performed in the direction of weakening the vanishing point of the route guidance image represented by an arrow mark towards the far side (upward), thereby generating a perspective image (virtual image) with a longer arrow length. On the other hand, for a relatively short viewer, the perspective adjustment is performed in the direction of strengthening the vanishing point of the route guidance image towards the near side (downward), thereby generating a perspective image with a shorter arrow length and displaying it on the image display unit 30. As a result, the downward angle LD (position of the eye box EB) prevents the impression that the route guidance image (virtual image) indicating a point to turn at an intersection, for example, points to a different point than the point to turn, and eliminates the problem of the relationship between the foreground and the virtual image being perceived differently depending on the viewer's height. Therefore, the displayed image (a route guidance image represented by an arrow mark displayed as a virtual image V) is displayed as a perspective image for route guidance at the target position in the foreground, regardless of the downward angle LD (position of the eye box EB), giving the same impression to drivers who are viewers of different heights and builds. In addition, for content that does not overlap the foreground, such as ADAS status and warning icons, the display image is suppressed from entering the effective field of view, especially for shorter drivers, thus eliminating the feeling of annoyance (intrusion).

[0102] The display control program of this embodiment is a display control program for a head-up display device (HUD device 100) that includes, for example, an image display unit 30 that displays a route guidance image for viewing by a viewer (driver DR) in the vehicle CR by superimposing the foreground in the forward field of view of the vehicle CR and a virtual image V onto a virtual image forming surface (display area VA) that is virtually set in front of the vehicle CR, as shown in Figures 1 and 2; an optical member (concave mirror 141 of the imaging optical system 130, 140) having a curved reflective surface that projects the route guidance image onto the virtual image forming surface (display area VA); and a control unit 10 that controls the rotational drive of the image display unit 30 and the optical member (concave mirror 141 of the imaging optical system 130, 140) to perform perspective adjustment to give a sense of depth to the route guidance image. The display control program, for example as shown in Figure 4, causes the processor in the control unit 10 to perform the following processes: (step ST104) to estimate the depression angle LD, which is the angle formed by a straight line parallel to the road surface (virtual line VL) from the viewer's eye position (eye point EP) in the height direction and a straight line connecting the viewer's eye position (eye point EP) and the center of the virtual image forming surface (display area VA), which is adjusted by rotating an optical element in response to the viewer's operation (step ST108 "YES"); and (step ST105 to ST110) to control the intensity of the perspective adjustment performed on the virtual path guidance image according to the estimated depression angle LD, and to display the virtual image generated by the perspective adjustment on the image display unit 30.

[0103] According to the display control program of this embodiment, the processor in the control unit reads and executes a program recorded in memory, thereby varying the intensity of perspective adjustment for the route guidance image according to the estimated downward angle LD (position of the eye box EB), and controls the display of the generated perspective image on the image display unit. Therefore, depending on the downward angle LD (position of the eye box EB), it is possible to eliminate the problem of the relationship between the foreground and the virtual image being perceived differently depending on the height and build of the viewer, without giving the impression that the system is pointing to a different location than where a turn should be made, such as an intersection. As a result, the displayed image (in this case, the route guidance image represented by an arrow mark displayed as a virtual image V) can give the same impression to drivers with different heights and builds, regardless of the position of the eye box. Furthermore, in the case of content that does not overlap the foreground, such as ADAS status or warning icons, even for short drivers, the display image is suppressed from entering the effective field of view, eliminating the problem of it being bothersome (intrusive).

[0104] The in-vehicle display system of this embodiment is an in-vehicle display system 1000 that includes, for example, a navigation device 200 that provides route guidance, and a head-up display device (HUD device 100) that superimposes the foreground in the forward field of view of the vehicle CR and the route guidance image generated by the navigation device 200 onto a virtual image forming surface (display area VA) virtually set in front of the vehicle CR, and makes it visible to a viewer in the vehicle CR. The head-up display device (HUD device 100) includes an image display unit 30 that displays a route guidance image, an optical element (concave mirror 141 of the imaging optical system 130, 140) having a curved reflective surface that projects the route guidance image onto a virtual image forming surface (display area VA), and a control unit 10 that controls the rotational drive of the image display unit 30 and the optical element (concave mirror 141 of the imaging optical system 130, 140) to perform perspective adjustment to give a sense of depth to the route guidance image. The control unit 10 controls the optical element based on the user's operation. The downward angle, which is the angle between a straight line parallel to the road surface (virtual line VL) from the viewer's eye position (eye point EP) in the height direction and a straight line connecting the viewer's eye position (eye point EP) and the center of the virtual image forming surface (display area VA), is estimated by rotating the concave mirror 141 of the imaging optical system 130, 140. The intensity of the perspective adjustment performed on the route guidance image is varied according to the estimated downward angle, and the perspective image V generated by the perspective adjustment is generated. Ｔ , V Ｓ This is an in-vehicle display system 1000 that controls the display of the image shown (see Figures 6A, 3A, 3B, and 7) on the image display unit.

[0105] According to the in-vehicle display system 1000 of this embodiment, the control unit 10 of the HUD device 100 varies the intensity of perspective adjustment for the route guidance image (virtual image V) generated by the navigation device 200 according to the adjusted depression angle LD (position of the eye box EB), and the generated perspective image V Ｔ , V ＳControl is performed to display the image on the image display unit 30. Therefore, the position of the eye box EB (downward angle LD) does not give the impression that it is pointing to a different location than where a turn should be made, such as an intersection, and the relationship between the foreground and the virtual image is perceived differently depending on the height and build of the viewer. For this reason, an in-vehicle display system 1000 can be provided in which the displayed image (in this case, a route guidance image represented by an arrow mark displayed as a virtual image) gives the same impression to drivers who are viewers of different heights and builds, regardless of the position of the eye box EB. In addition, in the case of content that does not overlap the foreground, such as ADAS status or warning icons, the display image does not enter the effective field of view even for short drivers, thus eliminating the problem of it being bothersome (intrusive).

[0106] The present invention is not limited to the exemplary embodiments described above, and those skilled in the art will be able to easily modify the exemplary embodiments described above to the extent included in the claims.

[0107] 10...Control unit, 20...Storage unit, 30...Image display unit, 100...Head-up display device (HUD device), 110...Drive unit, 120...Liquid crystal display, 130, 140...Imaging optical system, 141...Concave mirror, 200...Navigation device, 301...Eye position detection device, 302...Operation input device, 303...Vehicle monitoring device, 400...I / O interface, 1000...In-vehicle display system, EP...Eye point (viewpoint position), EB...Eye box, VL...Virtual line, LD...Depression angle, LD ＴＨ ...Angle reference value, IP...Instrument panel, DR...Driver (viewer), CR...Vehicle, WS...Windshield, VA...Display area (virtual image forming surface), L...Display light, V...Virtual image, VP ０ VP １ VP ２ ...vanishing point, V Ｔ , V Ｎ , V Ｓ ...Perspective image

Claims

1. A head-up display device that superimposes one or more virtual images onto a virtual image forming surface virtually set in front of a vehicle, onto which the foreground in the vehicle's forward field of view is visible to a viewer riding in the vehicle, the head-up display device comprising: an image display unit that displays a route guidance image; and a control unit that performs perspective adjustment to give the route guidance image a sense of depth, wherein the control unit varies the intensity of the perspective adjustment that gives the route guidance image a sense of depth according to the downward angle which is the angle between a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, and controls the display of the virtual image generated by the perspective adjustment on the image display unit.

2. The head-up display device according to claim 1, further comprising an optical member having a curved reflective surface that projects the virtual image onto the virtual image forming surface, wherein the control unit controls the intensity of the perspective adjustment to be variable based on the depression angle adjusted by rotating the optical member.

3. The head-up display device according to claim 2, wherein the control unit controls the weakening of the perspective adjustment when the depression angle is smaller than a predetermined angle reference value, and controls the strengthening of the perspective adjustment when the depression angle is larger than the predetermined angle reference value.

4. The head-up display device according to claim 2 or 3, wherein the control unit controls the display position of the virtual image to move downward by a predetermined amount when the depression angle is smaller than the predetermined angle reference value, and controls the display position of the virtual image to move upward by a predetermined amount when the depression angle is larger than the predetermined angle reference value.

5. A control method for a head-up display device comprising: an image display unit that displays a route guidance image, which is formed by superimposing the foreground in the forward field of view of the vehicle and one or more virtual images onto a virtual image forming surface virtually set in front of the vehicle, for the viewer to see; an optical member having a curved reflective surface that projects the route guidance image onto the virtual image forming surface; and a control unit that controls the rotational drive of the image display unit and the optical member to perform perspective adjustment to give a sense of depth to the route guidance image, wherein the control unit estimates a depression angle, which is the angle formed by a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, and the control unit, A control method for a head-up display device, comprising the steps of: varying the intensity of the perspective adjustment performed on the route guidance image according to the estimated depression angle, and controlling the display of the virtual image generated by the perspective adjustment on the image display unit.

6. A display control program for a head-up display device comprising: an image display unit that displays a route guidance image, which is formed by superimposing the foreground in the vehicle's forward field of view and a virtual image onto a virtual image forming surface virtually set in front of the vehicle, and allowing a viewer in the vehicle to view it; an optical member having a curved reflective surface that projects the route guidance image onto the virtual image forming surface; and a control unit that controls the rotational drive of the image display unit and the optical member to perform perspective adjustment to give the route guidance image a sense of depth, wherein the processor of the control unit performs a process of estimating a depression angle, which is the angle formed by a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, which is adjusted by rotating the optical member by the viewer's operation; A display control program that performs a process to vary the intensity of the perspective adjustment applied to the virtual path guidance image according to the estimated depression angle, and to control the display of the virtual image generated by the perspective adjustment on the image display unit.

7. An in-vehicle display system comprising: a navigation device that provides route guidance; and a head-up display device that superimposes the foreground in the vehicle's forward field of view and a route guidance image generated by the navigation device onto a virtual image forming surface virtually set in front of the vehicle, and displays the image to a viewer in the vehicle, wherein the head-up display device comprises: an image display unit that displays the route guidance image; an optical member having a curved reflective surface that projects the route guidance image onto the virtual image forming surface; and a control unit that controls the rotational drive of the image display unit and the optical member to perform perspective adjustment to give the route guidance image a sense of depth, wherein the control unit An in-vehicle display system that, in response to the operation of the viewer, estimates a depression angle which is the angle between a virtual line parallel to the road surface from the viewer's eye position in the height direction and a straight line connecting the viewer's eye position in the height direction and the center of the virtual image forming surface, adjusts by rotating the optical element, varies the intensity of the perspective adjustment performed on the route guidance image according to the estimated depression angle, and controls the display of the virtual image generated by the perspective adjustment on the image display unit.

Images