Display control device, display device, and display control method

Abstract

According to the present invention, in a display device capable of switching between and displaying a virtual image and a real image, a vibration correction effect that suppresses the relative positional deviation between an image and an actual scene caused by the vibration of a vehicle suppresses the sense of incongruity caused by the virtual image and the real image being different.　A display control device 80 includes: an image switching unit 84 for switching between using a virtual image Vm or a real image Rm; a vibration information acquisition unit 93 that acquires vibration information about a vehicle 1; and a shake correction unit 87 that performs shake correction to suppress shaking of the image. When the virtual image Vm is displayed, the shake correction unit 87 performs a first vibration correction for a first vibration that accompanies a relative angle change between the vehicle 1 and an actual scene around the vehicle 1. When the real image Rm is displayed, the shake correction unit 87 does not perform the first vibration correction or does not perform the first vibration correction and performs a second vibration correction for a second vibration that accompanies a relative position change between the vehicle 1 and a viewer 11.

Description

Display control device, display device, and display control method

[0001] The present invention relates to a display control device, a display device, a display control method, etc., that are mounted on a vehicle such as an automobile.

[0002] Patent Document 1 discloses a head-up display (HUD) device capable of switching between displaying a virtual image and a real image. In this patent document, the switching between the virtual image and the real image is achieved by mechanically changing the relative positions of a display panel (object to be observed), a dihedral corner reflector array, and a reflecting member (see FIG. 12,

[0050] , etc.).

[0003] Furthermore, Patent Document 2 describes that when a displayed image (virtual image) shakes due to pitching of a vehicle, etc., the shaking is suppressed by shake correction. In Patent Document 2, the content of shake correction is changed according to at least one of the projection distance and depression angle (

[0006] , etc.).

[0004] JP 2011-70074 A Japanese Patent No. 7042443 A

[0005] The inventors' research has revealed the following problems. (1) The effectiveness of vibration correction, which suppresses the relative positional deviation between an image and a real scene due to vehicle vibration, differs between real images and virtual images. (2) Vibration correction works effectively for virtual images displayed outside the vehicle, but may cause discomfort for real images displayed inside the vehicle. (3) Vibration correction is effective because virtual images displayed outside the vehicle are often superimposed on a real scene, and the relative positional relationship between the virtual image and the real scene is important. (4) On the other hand, real images displayed inside the vehicle can be perceived by vehicle occupants (viewers) as, for example, a novel aerial display installed inside the vehicle. In other words, real images have little relationship to the real scene around the vehicle (including the front), and viewers may perceive the real image as a member or part of the vehicle. Therefore, the real image naturally sways in the same way as the vehicle itself due to vehicle vibrations (posture changes). Forcibly correcting the position of the real image based on the vehicle's posture changes may result in a shift in the image's relative position to vehicle fixtures, such as the dashboard, which may cause discomfort to the viewer. (5) However, the vehicle may also experience a momentary positional movement (position shift) that is different from posture changes (changes involving rotation). In this case, the displayed real image also shifts with the vehicle's movement, but the viewer maintains the same position due to inertia. Therefore, the viewer may experience a sudden shift in the position of the real image, which may cause discomfort. It is preferable to perform appropriate display correction for such vehicle shifts. (6) The above-mentioned Patent Documents 1 and 2 do not describe these issues or any solutions to them. (7) Furthermore, the HUD device of Patent Document 1 switches between a virtual image and a real image through mechanical control. On the other hand, vibration correction is electrically controlled. Therefore, even if the technologies of Patent Documents 1 and 2 are combined, it is difficult to link the mechanical control and electrical control as described above. For example, when switching from a virtual image to a real image, the vibration correction method is changed, but the mechanical reconstruction of the optical system is not completed, and it is possible that timing mismatches may occur between the controls. Therefore, it is preferable to realize switching between virtual and real images by electrical control and ensure consistency (linkage) with vibration correction.

[0006] One of the objects of the present invention is to prevent discomfort caused by the difference in the effect of vibration correction, which suppresses the relative positional shift between an image and a real scene due to vehicle vibration, in a display device that can switch between displaying a virtual image and a real image.

[0007] Other objects of the present invention will become apparent to those skilled in the art by referring to the following exemplary aspects and best modes, as well as the accompanying drawings.

[0008] In order to facilitate an understanding of the outline of the present invention, the following examples are given of embodiments according to the present invention.

[0009] In a first aspect, a display control device is a display control device that is mounted on a vehicle and controls the display of an image on a display device that is capable of switching between a virtual image and a real image to be viewed by a viewer who is a passenger in the vehicle, and that has an image switching unit that switches between displaying the image as the virtual image or the real image, a vibration information acquisition unit that acquires vibration information related to vibrations of the vehicle while it is moving, and a vibration correction unit that performs vibration correction to suppress shaking of the image caused by the vibration and is capable of adjusting the amount of vibration correction, and when the virtual image is displayed as the image, the vibration correction unit performs a first vibration correction for a first vibration accompanied by a relative angle change between the vehicle and the real scenery around the vehicle based on the vibration information acquired by the vibration information acquisition unit, and when the real image is displayed as the image, the first vibration correction is not performed, or the first vibration correction is not performed and a second vibration correction is performed for a second vibration accompanied by a relative position change between the vehicle and the viewer based on the vibration information acquired by the vibration information acquisition unit.

[0010] In the first aspect, a first vibration correction (display correction for a change in the vehicle's posture accompanied by rotation) is performed on the virtual image in response to a first vibration associated with a relative angular change between the vehicle and the real scene. On the other hand, the first vibration correction is not performed on the real image because the real image has little relationship to the real scene and the first vibration correction may actually cause a sense of discomfort. This reduces the sense of discomfort that would occur if the first vibration correction were performed on the real image (e.g., a sense of discomfort due to a positional shift between the real image and a dashboard, etc.). However, instead of performing the first vibration correction on the real image, a second vibration correction may be performed on the second vibration associated with a relative positional change between the vehicle and the viewer (in other words, a positional change caused by, for example, shifting the vehicle in one direction). This reduces the sense of discomfort by suppressing a positional shift of the real image associated with a shift in the vehicle. The first and second vibration corrections can be achieved quickly and accurately by, for example, switching display correction algorithms in response to the type of vehicle vibration. Specifically, the first vibration correction can be realized by, for example, measuring acceleration and angular velocity using an IMU (inertial measurement unit), detecting "changes in the relative position and angle (rotation angle) between the vehicle and the real scene" based on "acceleration and angular velocity information," and correcting the positional deviation of the virtual image. The second vibration correction can be realized by, for example, detecting "changes in the relative position between the vehicle and the viewer" based on "acceleration information" measured by the IMU, and correcting the positional deviation of the real image.

[0011] In a second aspect dependent on the first aspect, the first vibration correction may be pitching correction for pitching of the vehicle or rolling correction for rolling of the vehicle.

[0012] According to the second aspect, it is possible to realize display correction for pitching or rolling of the vehicle for the virtual image.

[0013] In a third aspect dependent on the first or second aspect, the second vibration correction may be a shift correction that corrects a positional shift of the real image caused by a shift of the vehicle relative to the viewer.

[0014] According to the third aspect, it is possible to perform effective display correction for the positional deviation of the real image caused by shifting the vehicle.

[0015] In a fourth aspect, the display device includes a display control device of any one of the first to third aspects, a display unit that generates display light for the image, and an optical system that includes a plurality of optical elements and propagates the display light for the image through the plurality of optical elements to project it onto a projection target member provided in the vehicle.

[0016] According to this aspect, a high-performance display device can be realized in which the effect of vibration correction, which suppresses the relative positional shift between the image and the real scene due to vehicle vibration, is different between the virtual image and the real image, and the display can switch between virtual and real images to display a virtual image and a real image.

[0017] In a fifth aspect dependent from the fourth aspect, the display unit is capable of switching display light of the image as output light between a first polarized light in a first polarization state and a second polarized light in a second polarization state, the optical system includes a first reflecting mirror that reflects the first polarized light and transmits the second polarized light, a second reflecting mirror that reflects the second polarized light that has transmitted through the first reflecting mirror, and a third reflecting mirror that reflects the first or second polarized light reflected by the first or second reflecting mirror and projects the first or second polarized light onto a projection target provided in the vehicle, and the image switching unit in the display control device switches the display light of the image between the first polarized light and the second polarized light in a second polarization state to display the virtual image. When the polarization of the image is switched to the second polarization, a first light propagation path is formed via the optical system, and when the display light of the image is switched to the second polarization to display the real image, a second light propagation path is formed via the optical system. In addition, when the focal point of the optical system on the display unit side in the first light propagation path is set as a first focal point and the focal point of the optical system on the display unit side in the second light propagation path is set as a second focal point, in the first light propagation path, the display unit is located closer to the first reflecting mirror than the first focal point, and in the second light propagation path, the display unit is located farther from the first reflecting mirror than the second focal point.

[0018] According to the fifth aspect, in a display device capable of switching between a virtual image and a real image, the discomfort caused by the difference in the effect of vibration correction, which suppresses the relative positional deviation between the image and the real scene due to vehicle vibration, can be suppressed between the virtual image and the real image. This results in a highly functional display device. Furthermore, the display device of this aspect can switch the polarization state of the display light by electrical control when switching between the virtual image and the real image. In this case, there is an advantage in that it is easy to ensure consistency (linkage) with the electrical control of vibration correction. For the first and second polarized light, for example, S-polarized light (light whose electric field oscillates within the plane of incidence of the light) and P-polarized light (light whose electric field oscillates perpendicular to the plane of incidence of the light) can be used (however, the first polarized light may be P-polarized and the second polarized light may be S-polarized). This is merely an example and is not limiting. The first and second polarized light may have different polarization angles. However, in order to distinguish between the polarized light and the real image, it is preferable that the polarization angles differ by at least 22.5 degrees.

[0019] In a fifth aspect, the optical system includes a reflecting mirror having different optical characteristics for the first and second polarized light. In other words, the first polarized light is reflected by the first reflecting mirror, but the second polarized light is not reflected by the first reflecting mirror but is reflected by the second reflecting mirror. Therefore, the optical propagation path along which the first polarized light propagates (first optical propagation path) and the optical propagation path along which the second polarized light propagates (second optical propagation path) are necessarily different. Note that the optical propagation path can be, for example, the path of a principal ray (a ray representing the display light) along the optical axis of the optical system.

[0020] In order for light emitted from a light source to form an image, the light must be converged. Therefore, the optical system can be described as an optical component consisting of a single convex lens (positive lens). Here, a convex lens (positive lens) has two focal points, and the focal point on the light source side (display unit side) is generally referred to as the "front focal point." For ease of explanation, the "front focal point" will be simply referred to as the "focal point." If a light source (corresponding to a display unit) is positioned at this focal point, light passing through the convex lens will be parallel. On the other hand, if the light source (display unit) is closer to the focal point (closer along the optical axis) from the perspective of the convex lens, the light passing through the convex lens will diverge and not form an image. However, if a virtual ray of light is drawn in the opposite direction to the diverging direction of the light, the virtual ray of light will form an image at a position far from the convex lens (a position outside the vehicle), displaying a virtual image (more precisely, an "inverted virtual image"). A configuration in which the light source (display unit) and the focal point have the above-described relationship will be referred to as a "virtual image display configuration" in this specification. On the other hand, when the light source (display unit) is located farther away from the focal point as viewed from the convex lens, the light passing through the convex lens is converged and formed in front of the viewer in the vehicle interior, and a real image (more precisely, an "erect real image") is displayed. In this specification, a configuration in which the light source (display unit) and the focal point have the above-mentioned relationship is referred to as a "real image display configuration."

[0021] In the fifth aspect, when the first light propagation path is formed, a virtual image is displayed in the above-described "virtual image display configuration," and when the second light propagation path is formed, a real image is displayed in the above-described "real image display configuration." The display positions (imaging positions) of the virtual and real images can be adjusted, for example, by appropriately designing the radii of curvature of the first and second reflectors. Furthermore, for example, by changing the angle between the display surface of the display unit and the optical axis, it is also possible to appropriately adjust whether the virtual and real images are upright or inclined relative to the road surface on which the vehicle is traveling. Thus, the display device of this aspect can switch between the virtual and real images through electrical control, which has the advantages of being highly functional, compact, and capable of quickly switching between display images.

[0022] In a sixth aspect dependent on the fourth aspect, the display unit includes a first display unit that emits display light of a first image for displaying a virtual image, and a second display unit that emits display light of a second image for displaying a real image, and the optical system includes a fifth reflecting mirror that transmits the display light of the first image from the first display unit and reflects the display light of the second image from the second display unit, and a sixth reflecting mirror that reflects the display light of the first image transmitted through the fifth reflecting mirror and the display light of the second image reflected by the fifth reflecting mirror, and projects the display light onto a projection target provided in the vehicle. and wherein a propagation path of display light for the first image is a first light propagation path, a propagation path of display light for the second image is a second light propagation path, a focal point of the optical system on the first display unit side in the first light propagation path is a first focal point, and a focal point of the optical system on the second display unit side in the second light propagation path is a second focal point, in which, in the first light propagation path, the first display unit is located closer to the fifth reflector than the first focal point, and in the second light propagation path, the second display unit is located farther from the fifth reflector than the second focal point.

[0023] In a sixth aspect, a first display unit for displaying a virtual image and a second display unit for displaying a real image are provided as display units for displaying images (in other words, emitting display light for the image), and the control unit activates the first display unit when displaying a virtual image and activates the second display unit when displaying a real image. The first and second display units are each disposed at different positions within the HUD device, and the optical system includes a reflector (fifth reflector) that transmits display light for the first image when displaying a virtual image and reflects display light for the second image when displaying a real image. With this configuration, a "first light propagation path" is formed as a propagation path for display light for the first image when displaying a virtual image, and a "second light propagation path" is formed as a propagation path for display light for the second image when displaying a real image. When the first display unit is activated to display a virtual image, the relationship between the first display unit and the focal point in the first light propagation path becomes the above-described "virtual image display configuration," and the virtual image is displayed on the display surface (virtual image display surface). On the other hand, when the first display unit is enabled to display a real image, the relationship between the first display unit and the focal point in the second light propagation path becomes the above-mentioned "real image display configuration," and a real image is displayed on the display surface (real image display surface). The display positions (imaging positions) of the virtual image and the real image can be adjusted, for example, by appropriately designing the radius of curvature of each of the fourth and fifth reflecting mirrors. According to the display device of this aspect, the virtual image and the real image can be electrically switched and displayed under the control of the control unit. By appropriately switching the vibration correction mode in conjunction with this switching between the virtual image and the real image, it is possible to suppress the sense of discomfort felt by the viewer. In other words, the sense of discomfort caused by the difference in the effect of vibration correction, which suppresses the relative positional deviation between the image and the real scene due to vehicle vibration, between the virtual image and the real image, can be suppressed. Therefore, a highly functional display device is realized. The effects described in the fifth aspect can also be obtained in the display device of this aspect.

[0024] In a seventh aspect, a display control method is a display control method for controlling the display of an image on a display device that is mounted on a vehicle and is capable of allowing a viewer who is a passenger in the vehicle to view by switching between a virtual image and a real image, the display control method including a first step of switching between displaying the image as the virtual image and the real image, a second step of acquiring vibration information related to vibrations of the vehicle while traveling, and a third step of performing vibration correction to suppress shaking of the image associated with the vibration, wherein in the third step, when the virtual image is displayed as the image, a first vibration correction is performed for a first vibration accompanied by a relative angle change between the vehicle and the real scenery around the vehicle, and when the real image is displayed as the image, the first vibration correction is not performed, or the first vibration correction is not performed and a second vibration correction is performed for a second vibration accompanied by a relative position change between the vehicle and the viewer.

[0025] According to the seventh aspect, in the display control of a display device that can switch between displaying a virtual image and a real image, the effect of vibration correction that suppresses the relative positional shift between the image and the real scene due to vehicle vibration can suppress the discomfort caused by the difference between the virtual image and the real image.

[0026] Those skilled in the art will easily understand that the exemplified embodiments according to the present invention can be further modified without departing from the spirit of the present invention.

[0027] FIG. 1 is a diagram showing an example of the configuration of a head-up display (HUD) device to which the present invention is applied, capable of switching between displaying a virtual image and a real image and performing image vibration correction. FIGS. 2A and 2B are diagrams showing examples of displaying a virtual image displayed outside the vehicle and a real image displayed inside the vehicle. FIGS. 3A and 3B are diagrams showing an example of image vibration correction (pitching correction) corresponding to pitching of the vehicle, and FIGS. 3C and 3D are diagrams showing an example of image vibration correction (rolling correction) corresponding to rolling of the vehicle. FIG. 4 is a flowchart showing an example of a display control procedure in the HUD device (an example of display correction control for a change in attitude accompanied by rotation of the vehicle). FIGS. 5A and 5B are diagrams showing an example of a change in the relative positional relationship between the image and the viewer accompanying a movement of the vehicle's position (vehicle shift). FIG. 6 is a flowchart showing another example of a display control procedure in the HUD device (an example of display correction control for a vehicle shift). FIG. 7 is a diagram showing another example of the configuration of a head-up display (HUD) device to which the present invention is applied, which can switch between displaying a virtual image and a real image and can also perform image vibration correction.

[0028] The best mode described below is used to facilitate understanding of the present invention, and therefore, those skilled in the art should be aware that the present invention is not unduly limited by the embodiments described below.

[0029] First Embodiment: Refer to FIG. 1. FIG. 1 is a diagram showing an example of the configuration of a head-up display (HUD) device to which the present invention is applied, capable of switching between displaying a virtual image and a real image and performing image vibration correction. In A-1 of FIG. 1, the height direction of the vehicle 1 is the up-down direction (Y direction), the width direction of the vehicle 1 is the left-right direction (X direction), and the front-rear direction is the Z direction. In the example of FIG. 1, the vehicle 1 is assumed to be traveling on a road surface (not shown in FIG. 1, reference numeral 4 in FIG. 2). In the example of FIG. 1, the user of the HUD device (broadly speaking, a display device or a projection-type display device) 100 is assumed to be a driver 11 who is driving the vehicle 1. The "driver" can also be broadly referred to as a "passenger" aboard the vehicle 1, or as a "viewer" who visually recognizes the images (virtual image Vm, real image Rm).

[0030] The HUD device 100 can switch between displaying a virtual image and a real image, and such a HUD device may be referred to herein as a "dual HUD device (or dual HUD)." As shown in A-1 of FIG. 1, the HUD device (dual HUD device) 100 as a display device includes a display control device (processor) 80 including a control unit 81, a light source unit 94 that emits white light as a backlight, a display unit 96 (including a display panel 97 such as a liquid crystal panel and a polarization switching member 98 that can switch polarization by electrical control) that can switch the display light of an image as emitted light between a first polarized light (e.g., S-polarized light) that is a first polarization state and a second polarized light (e.g., P-polarized light) that is a second polarization state, and a light source unit 94 that can switch the display light of an image between a first polarized light (e.g., S-polarized light) that is a first polarization state and a second polarized light (e.g., P-polarized light). the first reflecting mirror 121, the second reflecting mirror 123 that reflects the second polarized light that has passed through the first reflecting mirror 121, and the third reflecting mirror 124 that reflects the first or second polarized light (P polarized light and S polarized light) reflected by the first or second reflecting mirror 121, 123 and projects the first or second polarized light (P polarized light and S polarized light) onto a projection target member (a light-transmitting reflection member: in this case, the windshield 2) provided on the vehicle 1; an exit window 125 that emits display light; and an actuator (denoted as "ACT" in the figure) 127 that can change the tilt angle of the display unit 96 with respect to the optical axis of the optical system 99.

[0031] The light source unit 94 also has a red light source unit RL, a green light source unit GL, and a blue light source unit BL, which are provided on the substrate CB.

[0032] The control unit 81 of the display control device 80 supplies an image signal (video signal) VID to the display panel 97 , and can display an image on the display surface of the display panel 97 .

[0033] The polarization switching member 98 is a polarizing element (a polarizer such as a polarizing plate) that selectively transmits the first and second polarized light based on a polarization switching control signal C1 output by the control unit 81. This polarization switching member 98 can rotate the transmission axis of the polarized light by 90° as needed, for example, by electrically controlling the molecular arrangement of the material.

[0034] Light is a type of electromagnetic wave, and light with a specific vibration direction is called polarized light. As described above, S-polarized light (light whose electric field oscillates within the plane of incidence of the light) and P-polarized light (light whose electric field oscillates perpendicular to the plane of incidence of the light) can be used as the first and second polarized light (however, the first polarized light may be P-polarized and the second polarized light may be S-polarized). This is just one example, and the present invention is not limited to this. The first and second polarized light only need to have different polarization angles. However, in order to distinguish between the polarized lights, it is preferable that the polarization angles differ by at least 22.5 degrees.

[0035] The white light emitted from the light source (white light source) unit 94 contains S-polarized light and P-polarized light in equal proportions. When this white light passes through the polarization switching member 98, either S-polarized light or P-polarized light is selectively emitted depending on the direction of the transmission axis.

[0036] However, simply removing one of the unnecessary polarized lights reduces the amount of light by half, so it is also possible to convert one of the unnecessary polarized lights into the other effective polarized light using, for example, a retardation plate and reuse it. Such modifications and applications can be made as appropriate.

[0037] In A-1 of Figure 1, when the control unit 81 of the display control device 80 switches the image display light to a first polarization (e.g., S polarization) to display a virtual image Vm, a first light propagation path (shown by a solid line in the figure) L1 passing through the optical system 99 is formed, and when the control unit 81 switches the image display light to a second polarization (e.g., P polarization) to display a real image Rm, a second light propagation path (shown by a dashed line in the figure) L2 passing through the optical system 99 is formed.

[0038] Here, if the focus F1 on the display unit 96 side of the first light propagation path L1 of the optical system 99 is defined as the "first focus" and the focus F2 on the display unit 96 side of the second light propagation path L2 is defined as the "second focus," then in the first light propagation path L1, the display unit 96 is located closer than the first focus F1 when viewed from the first reflecting mirror 121 (in other words, with the first reflecting mirror 121 as the reference), and in the second light propagation path L2, the display unit 96 is located farther than the second focus F2 when viewed from the first reflecting mirror 121 (in other words, with the first reflecting mirror 121 as the reference).

[0039] When defining the relative positional relationship between the first and second focal points F1 and F2 and the display unit 96, the first reflecting mirror 121 is used as the reference because, among the multiple reflecting mirrors (first reflecting mirror 121 to third reflecting mirror 124) that make up the optical system 99, the first reflecting mirror 121 is located closest to the display unit 96 and is therefore suitable as a positional reference.

[0040] The optical system 99 includes reflectors (first reflector 121, second reflector 123) that have different optical properties for the first and second polarized light. In other words, the first polarized light is reflected by the first reflector 121, but the second polarized light is not reflected by the first reflector 121 but passes through the first reflector 121 and is then reflected by the second reflector 123 that is disposed behind the first reflector 121 (on the opposite side from the display unit 96). The reflected light passes through the first reflector 121 again and heads toward the second reflector 123.

[0041] Therefore, the light propagation path along which the first polarized light propagates (first light propagation path L1) and the light propagation path along which the second polarized light propagates (second light propagation path L2) are necessarily different. Note that the light propagation path can be, for example, the path of the chief ray (a ray representative of the display light) along the optical axis of the optical system 99.

[0042] Generally, in order for light emitted from a light source to form an image, the light must be converged. Therefore, the optical system 99 can be considered an optical component that constitutes a single convex lens (positive lens). Here, a convex lens (positive lens) has two focal points, and the focal point on the light source side (the display unit side) is generally referred to as the "front focal point." For ease of explanation, the "front focal point" will be simply referred to as the "focal point" in this specification. If the light source (corresponding to the display unit) were positioned at this focal point, the light passing through the convex lens would be parallel. On the other hand, if the light source (the display unit) were closer to the convex lens than the focal point (closer along the optical axis), the light passing through the convex lens would diverge and not form an image. However, if a virtual ray of light were drawn in the direction opposite to the divergence of the light, the virtual ray of light would form an image at a position far from the convex lens (a position outside the vehicle), resulting in the display of a virtual image (more precisely, an "inverted virtual image").

[0043] 1A-1, the virtual image Vm displayed on the imaging surface (virtual image display surface) VS corresponds to the inverted virtual image. In this specification, the configuration in which the display unit 96 and the first focal point F1 have the above-mentioned relationship is referred to as a "virtual image display configuration."

[0044] On the other hand, when the light source (display unit 96) is located farther away than the focus point as viewed from the convex lens, the light passing through the convex lens is focused and formed at a position in front of the viewer 11 in the vehicle interior space, and a real image (more precisely, an "erect real image") is displayed.

[0045] 1A-1, the real image Rm displayed on the imaging surface (real image display surface) RS corresponds to the above-mentioned erect real image. In this specification, the configuration in which the display unit 96 and the second focal point F2 have the above-mentioned relationship is referred to as the "real image display configuration."

[0046] In the example of A-1 in Figure 1, when the first light propagation path L1 is formed, the above-mentioned "virtual image display configuration" is obtained and a virtual image Vm is displayed, and when the second light propagation path L2 is formed, the above-mentioned "real image display configuration" is obtained and a real image Rm is displayed.

[0047] The display positions (imaging positions) of the virtual image Vm and real image Rm can be adjusted, for example, by appropriately designing the radii of curvature of the first and second reflecting mirrors 121, 123 and the third reflecting mirror.

[0048] In a preferred embodiment, the radius of curvature of the first reflecting mirror 121 is preferably set larger than the radius of curvature of the second reflecting mirror 123. Furthermore, the radius of curvature of the third reflecting mirror 124 is preferably set larger than the radii of curvature of each of the first and second reflecting mirrors 121 and 123. By setting the radii of curvature in this manner, it becomes possible to display the virtual image Vm at a position a predetermined distance from the vehicle 1 in the space ahead of the vehicle 1, while displaying the real image Rm at a position between the viewer 11 and the projection target (windshield) 2 in the space inside the vehicle 1 (in other words, at an appropriate position slightly forward as seen by the viewer 11).

[0049] The radii of curvature of the reflecting mirrors 121 to 124 may not be uniform, but may be partially different, or the reflecting surfaces may be free-form surfaces, which allows, for example, adjustment of the inclination angle of the imaging surfaces (virtual image display surface VS, real image display surface RS) relative to the road surface 4 (see FIG. 2).

[0050] Furthermore, for example, by changing the angle that the display surface of the display unit 96 makes with respect to the optical axis, it is also possible to appropriately adjust whether each of the virtual image Vm and the real image Rm is an upright image or an inclined image with respect to the road surface 4 (see FIG. 2 ) of the road on which the vehicle 1 is traveling. The control unit 81 can appropriately change the angle that the display surface of the display unit 96 makes with respect to the optical axis by supplying a control signal to the actuator 127.

[0051] This makes it possible to change the imaging surface (virtual image display surface VS, real image display surface RS) from the attitude shown by the solid line to the attitude shown by the dashed line, for example, as shown in A-1 of Figure 1.

[0052] In addition, in the example of A-1 in Figure 1, the vehicle 1 is provided with, for example, a camera 5 that observes the movement of body parts such as the fingers of the viewer 11, and a command determination unit 130 that determines the command intended by the viewer 11.

[0053] For example, when an operation panel (reference numeral 9 in FIG. 2B) is displayed as an aerial display used to operate the equipment of the vehicle 1 as a real image, when the viewer 11 places his / her finger on a specific button on the operation panel, the camera 5 captures an image of the finger, and the captured image data is sent to the command determination unit 130.

[0054] The command determination unit 130 compares the position of the finger in the vehicle interior space with the position of the button on the virtual operation panel to determine the command intended by the viewer 11 (for example, a command to turn on the air conditioning), and generates a necessary control signal based on the determination result and sends the control signal to an ECU (Electronic Control Unit) 77. For example, the air conditioning equipment can be automatically turned on by control by the ECU 77. However, the above display example is merely an example and is not limited to this. Entertainment information or entertainment video (movie video, etc.) may also be displayed as the real image Rm.

[0055] The HUD device (dual HUD device) 100 as a display device A-1 in FIG. 1 is highly functional because it can switch between a virtual image and a real image by electrical control, and has the advantage of being compact because each component of the optical system can be arranged at an appropriate interval (close interval), and being able to switch between display images (virtual image Vm and real image Rm) at high speed.

[0056] Next, a configuration for performing vibration correction will be described with reference to A-2 in FIG.

[0057] As shown in A- 2 of FIG. 1, a HUD device (dual HUD device) 100 as a display device includes a display control device (processor) 80 and a projection unit 95 .

[0058] As shown in A-1 of FIG. 1, the projection unit 95 has a light source unit 94, a display unit 96 (including a display panel (such as a liquid crystal panel) 97 and a polarization switching member 98), and an optical system 99.

[0059] The display control device (processor) 80 also includes a control unit 81 .

[0060] The control unit 81 has a display content determination unit 83 that determines the image to be displayed, an image switching unit (virtual image / real image switching unit) 84 that switches between a virtual image and a real image, a display position determination unit 85 that determines the display position (arrangement) of the image on the imaging surface (virtual image display surface VS, real image display surface RS) (which may also include a depression angle calculation unit 86 that calculates the depression angle of the image as seen by the viewer 11), a shake correction unit 87, a display state change unit 92 that changes the display state, and a vibration information acquisition unit 93 that acquires vibration information of the vehicle such as pitching and rolling.

[0061] The shake correction unit 87 has a correction amount adjustment unit 88, which has a correction amount setting unit 89 that sets the correction amount for the shake correction process, a correction amount change unit 90 that performs correction amount change processing, and a correction amount return processing unit 91 that performs correction amount return processing.

[0062] The shake correction unit 87 has the function of detecting changes in the position and angle of the vehicle 1, or changes in position, based on acceleration information and angular velocity information supplied from the various sensors 75, and correcting the positional shift of the image that accompanies these changes.

[0063] The correction amount adjustment unit 88 can adjust the amount of correction used for vibration correction as needed. In principle, the amount of correction is set according to the detected changes in position and angle, but in some cases it is possible to weaken the degree of correction somewhat or set the amount of correction to zero, thereby disabling vibration correction.

[0064] The correction amount for vibration correction is changed by a correction amount change unit 90. The changed correction amount is set in a correction amount setting unit 89. Vibration correction is performed based on the latest correction amount that has been set. Note that a correction amount return processing unit 91 performs processing to restore the changed correction amount to its original value.

[0065] The following describes a characteristic operation of vibration correction in this embodiment. In the following description, vibrations that involve a relative angle change between the vehicle 1 and the actual scene are referred to as "first vibrations," and vibration correction for the "first vibrations" is referred to as "first vibration correction (display correction for a change in the vehicle's attitude that involves rotation)."

[0066] In the example of Figure 1, the first vibration correction (display correction for the vehicle's posture change accompanied by rotation) is performed on the virtual image Vm in response to the first vibration that involves a relative angle change between the vehicle 1 and the real scene, while the first vibration correction is not performed on the real image Rm because it has little relationship with the real scene and the first vibration correction may actually cause a sense of incongruity.

[0067] Such control can be realized by the correction amount adjustment unit 87 in the control unit 81 setting the correction amount to zero when the real image Rm is displayed.

[0068] For example, when the image switching unit (virtual image / real image switching unit) 84 of the control unit 81 issues a polarization switching control signal C1 to the polarization switching member 98 in the display unit 96 to switch the polarization state and switch the emitted display light from the first polarization to the second polarization (in other words, when switching from virtual image display to real image display), the correction amount adjustment unit 89, for example, operates in conjunction with (in a preferred example, synchronized with) the polarization switching control signal C1 to set the correction amount for the first vibration correction to zero.

[0069] In this way, the correction amount for the first vibration can be switched at high speed with accurate timing in conjunction with (synchronization with) the switching of polarization.

[0070] Therefore, according to this embodiment, when the display image is switched from the virtual image Vm to the real image Rm, unnecessary vibration correction can be disabled at the correct timing.

[0071] This makes it possible to reliably suppress the sense of incongruity that occurs when the first vibration correction is performed on the real image Rm (for example, the sense of incongruity caused by a positional shift between the real image and a dashboard or the like).

[0072] Here, the "first vibration correction" may be pitching correction for pitching of the vehicle 1 or rolling correction for rolling of the vehicle 1. This makes it possible to realize display correction for pitching or rolling of the vehicle 1 for the virtual image Vm. Details of pitching correction and rolling correction will be described later with reference to FIG. 3 .

[0073] The vehicle 1 is also provided with various sensors (such as an acceleration sensor) 75 and an ECU 77 that can collect various types of vehicle information.

[0074] Next, let us refer to Figure 2. Figures 2(A) and 2(B) are diagrams showing examples of a virtual image displayed outside the vehicle and a real image displayed inside the vehicle. In Figure 2, the same parts as in Figure 1 are given the same reference numerals.

[0075] Fig. 2(A) shows a display example when the image formation surfaces (virtual image display surface VS, real image display surface RS) are in the orientation shown by the solid lines in A-1 of Fig. 1 (the virtual image display surface VS is an inclined surface, and the real image display surface RS is a vertical image surface). Fig. 2(B) shows a display example when the image formation surfaces (virtual image display surface VS, real image display surface RS) are in the orientation shown by the broken lines in A-1 of Fig. 1 (the virtual image display surface VS is a vertical image surface, and the real image display surface RS is an inclined surface).

[0076] In Fig. 2(A), a vehicle 1 is traveling on a road surface 4. When a virtual image is displayed, an imaging surface (virtual image display surface) VS is set in front of (relatively close to) the vehicle 1, and a navigation image Q1 as a virtual image Vm is displayed on this imaging surface VS so as to be superimposed on the road surface. Note that the navigation image Q1 shown in Fig. 2(A) is an example of an image to be displayed.

[0077] In addition, in Figure 2 (A), an imaging surface (real image display surface) RS is set in the internal space of the vehicle 1 (the space in front of the viewer 11), and a voice assistance icon 4 is displayed on this imaging surface (real image display surface) RS, which is used, for example, to respond to the viewer 11's speech by voice to provide various information or to operate equipment within the vehicle.

[0078] 2B, an attention drawing mark Q2 is displayed as a virtual image Vm on an imaging surface (virtual image display surface) VS. This attention drawing mark Q2 is displayed so as to be superimposed on a vehicle (not shown) ahead whose inter-vehicle distance is shortening, for example.

[0079] In addition, in Figure 2 (B), an operation panel 9 as an aerial display, which is used to operate equipment in the vehicle 1, is displayed on an imaging surface (real image display surface) RS set up inside the vehicle 1.

[0080] Next, reference will be made to Fig. 3. Figs. 3A and 3B are diagrams showing an example of image vibration correction (pitching correction) corresponding to pitching of a vehicle, and Figs. 3C and 3D are diagrams showing an example of image vibration correction (rolling correction) corresponding to rolling of a vehicle. Note that in Fig. 3, the XYZ Cartesian coordinate system is a coordinate system of real space with the road surface as a reference.

[0081] Pitching of the vehicle 1 is a state in which the vehicle rotates back and forth around the left-right axis of the vehicle 1 (an axis that passes through the center of the vehicle (e.g., the center of gravity) and extends in the left-right direction of the vehicle 1), causing a so-called vertical sway, and the posture of the vehicle 1 becomes a backward-leaning posture (see Figure 3(A)) or a forward-leaning posture (see Figure 3(B)).

[0082] 3A, the vehicle 1 is traveling on a flat road surface 4. However, due to sudden acceleration, for example, the front end of the vehicle body of the vehicle 1 is lifted off the road surface 4, and the vehicle body of the vehicle 1 is in a backward tilted position. The pitching angle is θa.

[0083] 3B, for example, due to sudden braking, the rear end of the vehicle body of the vehicle 1 is lifted off the road surface 4, and the vehicle body of the vehicle 1 is in a forward tilt position. The pitching angle is θb.

[0084] When pitching occurs, a misalignment (mismatch) occurs between an XYZ Cartesian coordinate system (first coordinate system) set in real space with the road surface 4 as the reference and a local X1Y1Z1 Cartesian coordinate system (second coordinate system) that fluctuates depending on the posture of the body of the vehicle 1. This misalignment causes fluctuations in the display position of the image. Pitching correction is image correction that suppresses this fluctuation (basically, coordinate conversion correction that converts the second coordinate system into the first coordinate system).

[0085] As shown by the solid lines at the top of Figures 3(A) and (B), before pitching occurs, for example, a caution mark (virtual image) 70 is displayed superimposed on a forward object (e.g., a vehicle ahead) 60. However, when pitching occurs, as shown by the dashed lines, the position of the caution mark (virtual image) moves in the vertical direction (the height direction (Y direction) of the vehicle 1 in the XYZ Cartesian coordinate system). In Figure 3(A), the amount of displacement is denoted as ΔD1. In Figure 3(B), the amount of displacement is denoted as ΔD2. In addition, in the figures, the caution mark (virtual image) after the positional displacement has occurred is denoted by the symbol 70'.

[0086] Furthermore, the rolling of the vehicle 1 is a state in which the vehicle 1 rotates left and right around the longitudinal axis (an axis that passes through the center of the vehicle (e.g., the center of gravity) and extends in the longitudinal direction of the vehicle 1), causing a so-called lateral sway, and the posture of the vehicle 1 becomes a right-leaning posture (see FIG. 3(C)) or a left-leaning posture (see FIG. 3(D)).

[0087] When rolling occurs, a misalignment (mismatch) occurs between an XYZ Cartesian coordinate system (first coordinate system) set in real space with the road surface 4 as the reference and a local X1Y1Z1 Cartesian coordinate system (second coordinate system) that fluctuates depending on the posture of the body of the vehicle 1. This misalignment causes fluctuations in the display position of the image. Rolling correction is image correction that suppresses this fluctuation (basically, coordinate conversion correction that converts the second coordinate system into the first coordinate system).

[0088] 3C, for example, the steering wheel is turned to the left, causing the left end of the vehicle 1 to lift off the road surface 4, and the vehicle 1 to tilt to the right. The rolling angle is θc.

[0089] 3D, for example, the steering wheel is turned to the right, causing the right end of the body of the vehicle 1 to lift off the road surface 4, and the body of the vehicle 1 to tilt to the left. The rolling angle is θd.

[0090] As shown by the solid lines at the top of Figures 3(C) and (D), before rolling occurs, the attention warning mark (virtual image) 70 is displayed superimposed on the object ahead (e.g., the vehicle ahead) 60, but when rolling occurs, as shown by the dashed lines, the position of the attention warning mark (virtual image) moves in the left-right direction (the width direction (X direction) of the vehicle 1 in the XYZ Cartesian coordinate system) and the up-down direction (the height direction (Y direction) of the vehicle 1 in the XYZ Cartesian coordinate system).

[0091] In Fig. 3(C), the amount of displacement in the left-right direction (yawing component) is denoted as ΔL1, and the amount of displacement in the up-down direction is denoted as ΔD3. In Fig. 3(D), the amount of displacement in the left-right direction (yawing component) is denoted as ΔL2, and the amount of displacement in the up-down direction is denoted as ΔD4. The attention drawing mark (virtual image) after the positional movement has occurred is labeled 70'.

[0092] Next, reference is made to Fig. 4. Fig. 4 is a flowchart showing an example of a procedure for display control in the HUD device (an example of display correction control in response to a change in attitude accompanied by rotation of the vehicle).

[0093] In step S1, vehicle vibration information is acquired.

[0094] In step S2, the display correction amount (the correction amount of the first vibration correction) is calculated.

[0095] In step S3, the display image data is acquired.

[0096] In step S4, image switching information (information indicating whether to display a virtual image or a real image) is acquired.

[0097] In step S5, it is determined whether the image to be displayed is a virtual image. If the answer is Y, the process proceeds to step S6, and if the answer is N, the process proceeds to step S7.

[0098] In step S6, vibration correction (first vibration correction) is performed based on the display correction amount (correction amount of first vibration correction) calculated in step S2.

[0099] In step S7, the image after the vibration correction is output.

[0100] Second Embodiment Referring to Fig. 5, Figs. 5A and 5B are diagrams showing an example of a change in the relative positional relationship between an image and a viewer accompanying a change in the position of a vehicle (shifting of the vehicle).

[0101] In this embodiment, a case where the second vibration correction is performed on the real image Rm instead of the first vibration correction will be described. Here, the second vibration correction is a shift correction that corrects a positional shift of the real image Rm caused by a shift of the vehicle 1 relative to the viewer 11.

[0102] In other words, there may be cases where the vehicle 1 experiences an instantaneous positional movement (positional shift) that is different from an attitude change (a change involving rotation).

[0103] In this case, the displayed real image Rm also shifts as the vehicle 1 moves, but the viewer 11 maintains the same position due to inertia, and therefore the position of the real image Rm may appear to have shifted suddenly, causing discomfort to the viewer 11. It is preferable to perform appropriate display correction for such shifts of the vehicle 1.

[0104] In FIG. 5A, a voice assistance icon 6 is displayed as a real image on an imaging surface (real image display surface) RS in front of a viewer 11.

[0105] 5B, the vehicle 1 momentarily moves (shifts) to the left, and the real image of the voice assistance icon 6 also shifts to the left. In this case, the second vibration correction is a correction that returns the real image of the voice assistance icon 6 to its original position.

[0106] By performing this second vibration correction, it is possible to suppress the positional shift of the real image caused by shifting the vehicle 1, thereby reducing the sense of discomfort.

[0107] The first and second vibration corrections can be realized quickly and accurately by, for example, switching the display correction algorithm in accordance with the mode of vibration of the vehicle.

[0108] Specifically, the first vibration correction can be realized by, for example, measuring acceleration and angular velocity using an IMU (inertial measurement unit), detecting "changes in the relative position and angle (rotation angle) between the vehicle and the real scene" based on "acceleration and angular velocity information," and correcting the positional deviation of the virtual image. The second vibration correction can be realized by, for example, detecting "changes in the relative position between the vehicle and the viewer" based on "acceleration information" measured by the IMU, and correcting the positional deviation of the real image.

[0109] Please refer to Fig. 6. Fig. 6 is a flowchart showing another example of the procedure for display control in the HUD device (an example of display correction control in response to a shift of the vehicle).

[0110] In Fig. 6, step S2 in Fig. 4 is replaced with step S2', and step S8 is added, which was not present in Fig. 4. The other steps are the same as in Fig. 4, and therefore description thereof will be omitted.

[0111] In step S2', a first or second display correction amount is calculated. The first display correction amount is, in other words, the correction amount for the first vibration correction. The second display correction amount is, in other words, the correction amount for the second vibration correction.

[0112] In step S8, if the answer is N in step S5, vibration correction (second vibration correction) based on the second display correction amount (correction amount of second vibration correction) is performed.

[0113] (Third Embodiment) Please refer to FIG. 7. FIG. 7 is a diagram showing another example of the configuration of a head-up display (HUD) device to which the present invention is applied, capable of switching between displaying a virtual image and a real image and performing image vibration correction. In FIG. 7, parts that are common to A-1 in FIG. 1 are assigned the same reference numerals as much as possible. However, some reference numerals have been intentionally changed to distinguish the features of this embodiment from A-1 in FIG. 1. Note that the configuration in FIG. 7 also uses a control unit 81 with a vibration correction function, configured similarly to that shown in A-2 in FIG. 1. Since vibration correction has been explained above, its explanation will be omitted. Furthermore, the following explanation will mainly focus on differences from A-1 in FIG. 1, and explanation of matters already explained in A-1 in FIG. 1 may be omitted.

[0114] In this embodiment, a first display unit 212 for displaying a virtual image and a second display unit 222 for displaying a real image are provided as display units for displaying an image (in other words, for emitting display light for the image). The first display unit 212 has a first display panel (a first display such as a liquid crystal display device) 213, and the second display unit 222 has a second display panel (a second display such as a liquid crystal display device) 223. A control unit 81 of a display control device (processor) 80 enables the first display unit 212 (and the first light source unit 211) when displaying a virtual image, and enables the second display unit 222 (and the second light source unit 221) when displaying a real image.

[0115] 7 , the HUD device 100′ is provided with a first display unit 212 (and a first light source unit 211) that emits display light L3 of a first image to display a virtual image Vm, and a second display unit 222 (and a second light source unit 221) that emits display light L4 of a second image to display a real image Rm. Note that in the drawing, the display light L3 of the first image (or a first light propagation path for a chief ray along the optical axis of the optical system 230) is depicted by a solid line, and the display light L4 of the second image (or a second light propagation path for a chief ray along the optical axis of the optical system 230) is depicted by a dashed line.

[0116] In the example of Figure 7, the optical system 230 includes a fourth reflecting mirror (concave mirror) 234 that reflects the display light L4 of the second image emitted from the second display unit 222 (display panel 223) (however, this fourth reflecting mirror has the function of realizing, for example, miniaturization of the HUD device 100' by folding back the display light of the second image, but is not an essential component of the second light propagation path and may be omitted), a fifth reflecting mirror (concave mirror) 235 that transmits the display light L3 of the first image from the first display unit 212 (display panel 213) and reflects the display light L4 of the second image from the second display unit 222, and a sixth reflecting mirror 236 that reflects the display light L3 of the first image that has transmitted through the fifth reflecting mirror 235 and the display light L4 of the second image that has been reflected by the fifth reflecting mirror 235, and projects them onto the projection target member (windshield) 2 provided on the vehicle 1. Regarding the fifth reflector 235, it is stated above that "it also reflects the display light L4 of the second image from the second display unit 222," but this statement can be more accurately rephrased as "it also reflects, if the fourth reflector 234 is provided, the display light L4 of the second image emitted from the second display unit 222 and reflected by the fourth reflector 234, or, if the fourth reflector 234 is omitted, it reflects the display light L4 of the second image emitted from the second display unit 222 and arriving therefrom."

[0117] The propagation path of display light L3 of the first image (in FIG. 7 , the propagation path of the chief ray along the optical axis of optical system 230) is defined as a first light propagation path, and the propagation path of display light of the second image (in FIG. 7 , the propagation path of the chief ray along the optical axis of optical system 230) is defined as a second light propagation path. When the focal point of optical system 230 on the first display unit 212 side in the first light propagation path is defined as a first focal point F3 and the focal point of optical system 230 on the second display unit 222 side in the second light propagation path is defined as a second focal point F4, in the first light propagation path, the first display unit 212 is located closer to fifth reflecting mirror 235 (in other words, with fifth reflecting mirror 235 as a reference) than the first focal point F3, and in the second light propagation path, the second display unit 222 is located farther from fifth reflecting mirror 235 than the second focal point F4.

[0118] According to the display device of this aspect, it is possible to electrically switch between a virtual image and a real image under the control of the control unit, and by appropriately switching the vibration correction mode in conjunction with this switching between the virtual image and the real image, it is possible to suppress the sense of discomfort felt by the viewer. In other words, it is possible to suppress the sense of discomfort caused by the difference in the effect of vibration correction, which suppresses the relative positional deviation between the image and the real scene due to vehicle vibration, between the virtual image and the real image. Thus, a highly functional display device is realized. Note that the effects described in the fifth aspect can also be obtained in the display device of this aspect.

[0119] The control unit 81 of the display control device 80 can supply image signals (video signals) VID1 and VID2 to each of the first display unit 212 and the second display unit 222, thereby displaying images on the display surfaces of the first display unit 212 and the second display unit 222.

[0120] When the control unit 81 of the display control device 80 emits display light L3 of the first image from the first display unit 212 to display the virtual image Vm, a first light propagation path L3 (shown by a solid line in the figure) passing through the optical system 230 is formed, while when the control unit 81 emits display light L4 of the image from the second display unit 222 to display the real image Rm, a second light propagation path L4 (shown by a dashed line in the figure) passing through the optical system 230 is formed.

[0121] Here, if the focus F3 on the first display unit 212 side of the first light propagation path L3 of the optical system 230 is defined as the "first focus," and the focus F4 on the second display unit 222 side of the second light propagation path L4 is defined as the "second focus," then in the first light propagation path L1, the first display unit 212 is located closer than the first focus F3 when viewed from the fifth reflector 235 (in other words, with the fifth reflector 235 as the reference), and in the second light propagation path L2, the second display unit 222 is located farther than the second focus F4 when viewed from the fifth reflector 235 (in other words, with the fifth reflector 235 as the reference).

[0122] The fifth reflecting mirror 235 is a reflective / transmissive member that reflects at least a portion of the light from the second display unit 222 and transmits at least a portion of the light from the first display unit 212. The fifth reflecting mirror 235 is a reflective / transmissive member that reflects a portion of the light and transmits the other light, such as a half mirror, and transmits a portion of the display light L3 of the first image from the first display unit 212 toward the sixth reflecting mirror 236, while reflecting a portion of the display light L4 of the second image from the second display unit 222 toward the sixth reflecting mirror 236. Note that the fifth reflecting mirror 235 may be a reflecting mirror that has different optical characteristics for the first and second polarized light. In other words, the fifth reflecting mirror 235 may reflect the first polarized light but may also reflect the second polarized light.

[0123] 7 , in the HUD device 100′, when an image signal (video signal) VID1 is supplied to the first display unit 212, the first display unit 212 (and the first light source unit 211) are enabled to display the virtual image Rm. In this case, in the first light propagation path, the relationship between the first display unit 212 and the first focal point F3 becomes the “virtual image display configuration” previously described in A-1 of FIG. 1 , and the virtual image Vm is displayed on a display surface (virtual image display surface) VS that is virtually provided in the space ahead of the vehicle 1. On the other hand, when an image signal (video signal) VID2 is supplied to the second display unit 222, the second display unit 222 (and the second light source unit 221) are enabled to display the real image Rm. In this case, in the second light propagation path, the relationship between the second display unit 222 and the second focal point F4 becomes the above-mentioned "real image display configuration," and a real image Rm is displayed on a display surface (real image display surface) Rs provided in the interior space of the vehicle 1 (the space in front of the viewer 11).

[0124] In the example of Figure 7, the display content determination unit 83 of the control unit 81 shown in A-1 of Figure 1 determines each of the images to be displayed by the first display unit 212 and the second display unit 222, unlike the example of A-1 of Figure 1.

[0125] 7 , the virtual image Vm (displayed by the first display unit 212) is subjected to first vibration correction (display correction for a change in the vehicle's posture accompanied by rotation) in response to a first vibration resulting from a change in the relative angle between the vehicle 1 and the real scene. On the other hand, the real image Rm (displayed by the second display unit 222) is not subjected to first vibration correction because the real image Rm has little relationship to the real scene and the first vibration correction may actually cause a sense of incongruity. Such control can be realized, for example, by the correction amount adjustment unit 87 in the control unit 81 setting the correction amount to zero when the real image Rm (second display unit 222) is displayed.

[0126] As described above, according to the present invention, in a display device that can switch between displaying a virtual image and a real image, the effect of vibration correction that suppresses the relative positional shift between the image and the real scene due to vehicle vibration can be reduced, thereby reducing the sense of discomfort that arises when the effect is different between the virtual image and the real image.

[0127] The present invention is not limited to the above-described embodiments, and various modifications and applications are possible. HUD devices and display systems also include those used as simulators (for example, aircraft simulators, simulators as game devices, etc.).

[0128] Furthermore, in the above-described embodiment, the projection display device has been mainly described as an example of a HUD device, but the present invention is not limited to this, and for example, an in-car projector or the like can also be used.

[0129] The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent that they fall within the scope of the claims.

[0130] 1...Vehicle (own vehicle), 2...Projected member (windshield, etc.), 4...Road surface, 5...Camera (camera observing viewer's body part (finger, etc.)), 6...Voice assistance icon, 7...Viewer's finger, 9...Device operation icon as aerial display, 11...Viewer (passenger, driver), 75...Various sensors (acceleration sensor, etc.), 77...ECU, 80...Display control device (processor), 81...Control unit, 83...Display content determination unit, 84...Image switching unit (virtual image / real image switching unit), 85...Display position setting unit, 86...Depression angle calculation unit, 87...Shake correction unit, 88...Correction amount adjustment unit, 89...Correction amount setting unit, 90...Correction amount change unit, 91...Correction amount return processing unit, 92...Display state change unit, 93...Vibration information acquisition unit, 94...Light source unit, 95...Projection unit, 96...Display unit, 97...Display panel (liquid crystal panel, etc.), 98...Polarization switching member ( Polarization switching unit), 99...optical system, 100, 100'...HUD device, 121...first reflecting mirror (first concave mirror), 123...second reflecting mirror (second concave mirror), 124...third reflecting mirror (third concave mirror), 125...exit window, 127...actuator, 130...command determination unit, 211...first light source unit, 212...first display unit, 213...first display panel (first display), 221...second light source unit, 222...second Display unit, 223...second display panel (second display), 230...optical system, 234...fourth reflecting mirror (concave mirror), 235...fifth reflecting mirror (concave mirror), 236...sixth reflecting mirror (concave mirror), VS...imaging surface (display surface, virtual image display surface), RS...imaging surface (display surface, real image display surface), Vm...virtual image, Rm...real image, F1, F3...first focus, F2, F4...second focus, Q1...navigation image, Q2...attention warning mark.

Claims

1. A display control device for controlling the display of an image of a display device mounted on a vehicle and capable of switching and visually presenting a virtual image or a real image as the image to a viewer who is a passenger of the vehicle, the display control device comprising: an image switching unit that switches whether the image is a virtual image or a real image; a vibration information acquisition unit that acquires vibration information regarding vibration of the vehicle during travel; and a shake correction unit that performs shake correction to suppress shaking of the image accompanying the vibration and is capable of adjusting a correction amount of the shake correction, wherein when the virtual image is displayed as the image, the shake correction unit performs first vibration correction for first vibration accompanied by a relative angular change between the vehicle and a real scene around the vehicle based on the vibration information acquired by the vibration information acquisition unit, and when the real image is displayed as the image, the first vibration correction is not performed, or the first vibration correction is not performed and second vibration correction for second vibration accompanied by a relative position change between the vehicle and the viewer is performed based on the vibration information acquired by the vibration information acquisition unit.

2. The display control device according to claim 1, wherein the first vibration correction is pitching correction for pitching of the vehicle or rolling correction for rolling of the vehicle.

3. The display control device according to claim 1, wherein the second vibration correction is shift correction for correcting a positional shift of the real image caused by a shift of the vehicle with respect to the viewer.

4. A display device comprising the display control device according to any one of claims 1 to 3, a display unit that generates display light of the image, and an optical system that includes a plurality of optical elements and propagates the display light of the image through the plurality of optical elements to project the image onto a projection member provided on the vehicle.

5. The display unit can switch the display light of the image as the emitted light between a first polarization which is a first polarization state and a second polarization which is a second polarization state. The optical system includes a first reflector that reflects the first polarization and transmits the second polarization, a second reflector that reflects the second polarization that has passed through the first reflector, and a third reflector that reflects the first or second polarization reflected by the first or second reflector and projects it onto a projection member provided on the vehicle. When the image switching unit in the display control device switches the display light of the image to the first polarization in order to display the virtual image, a first light propagation path passing through the optical system is formed. When the display light of the image is switched to the second polarization in order to display the real image, a second light propagation path passing through the optical system is formed. In a case where the focus on the display unit side in the first light propagation path of the optical system is defined as a first focus and the focus on the display unit side in the second light propagation path is defined as a second focus, in the first light propagation path, the display unit is located closer to the first reflector than the first focus. In the second light propagation path, the display unit is located farther from the first reflector than the second focus. The display device according to claim 4.

6. As the display unit, a first display unit that emits display light of a first image for displaying a virtual image and a second display unit that emits display light of a second image for displaying a real image are provided. The optical system includes a fifth reflector that transmits the display light of the first image from the first display unit and reflects the display light of the second image from the second display unit, and a sixth reflector that reflects the display light of the first image transmitted through the fifth reflector and the display light of the second image reflected by the fifth reflector and projects them onto a projection member provided on the vehicle. The propagation path of the display light of the first image is defined as a first light propagation path, and the propagation path of the display light of the second image is defined as a second light propagation path. When the focus on the first display unit side in the first light propagation path of the optical system is defined as a first focus and the focus on the second display unit side in the second light propagation path is defined as a second focus, in the first light propagation path, the first display unit is located closer to the fifth reflector than the first focus, and in the second light propagation path, the second display unit is located farther from the fifth reflector than the second focus. The display device according to claim 4.

7. A display control method for controlling the display of an image of a display device mounted on a vehicle and capable of switching and visually presenting a virtual image or a real image as an image to a viewer who is a passenger of the vehicle, the method including: a first step of switching whether the image is the virtual image or the real image; a second step of acquiring vibration information regarding vibration of the vehicle during travel; and a third step of performing shake correction to suppress shaking of the image accompanying the vibration. In the third step, when the virtual image is displayed as the image, first vibration correction for a first vibration accompanied by a relative angular change between the vehicle and the actual scene around the vehicle is performed, and when the real image is displayed as the image, the first vibration correction is not performed, or the first vibration correction is not performed and second vibration correction for a second vibration accompanied by a relative positional change between the vehicle and the viewer is performed. Display control method.

Images