Display device for vehicle
The vehicle display device addresses focus adjustment issues by dynamically adjusting images on oblique and elevation planes, enhancing viewer comfort during transitions between real and virtual images.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NIPPON SEIKI CO LTD
- Filing Date
- 2025-12-18
- Publication Date
- 2026-06-25
AI Technical Summary
Existing vehicle display devices face difficulties in focus adjustment when switching between real and virtual images on an oblique image plane due to zooming in/out, as the upper part of the image appears to recede or approach, making it hard for viewers to adjust their focus.
A vehicle display device with a control unit that controls display units to perform image plane display processes on oblique and elevation planes, and dynamically zooms and slides images between the far-focus and near-focus sides, to reduce the difficulty in focus adjustment, by dynamically zooming in and sliding the oblique image plane, and the elevation image plane, dynamically adjusting the focus and position of images to align with the viewer's perspective.
The solution reduces the difficulty in focus adjustment by dynamically adjusting the focus and position of images, allowing viewers to easily transition between real and virtual images on oblique and elevation planes.
Smart Images
Figure JP2025044253_25062026_PF_FP_ABST
Abstract
Description
Vehicle display device
[0001] The present invention relates to a vehicle display device that performs a desired display for a viewer in a vehicle.
[0002] Conventionally, for example, a vehicle display device described in Patent Document 1 is known. In this vehicle display device, when switching between a real image and a virtual image of a display image represented by display light for the occupant to view, the virtual image is made to be viewed on an oblique image plane that is inclined such that the upper end side is in the back and the lower end side is in the front.
[0003] Japanese Patent Application Laid-Open No. 2018-159882
[0004] Here, in a configuration where a display image is viewed on an oblique image plane as in the above prior art, there may be a case where a dynamic display (so-called animation) such as zooming in on an image is performed when switching from a real image to a virtual image display. However, when zooming in on an image from the center of the field of view of an occupant who is a viewer, for example, on an oblique image plane, among the zoom-in images whose size increases as if approaching the front, the upper part of the oblique image plane appears to be far away in the back, so there is a problem that it is difficult for the viewer to adjust the focus. Also, conversely, when switching from a virtual image to a real image display and performing a zoom-out of the image to the center of the field of view on the oblique image plane, among the zoom-out images whose size decreases as if moving away in the back, the upper part of the oblique image plane appears to approach the front, so there is also a problem that it is difficult for the viewer to adjust the focus in this case.
[0005] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a vehicle display device that can reduce the difficulty of focus adjustment for a viewer in a zoom display when a display image is viewed on an oblique image plane.
[0006] The present invention relates to a vehicle display device 1 provided in a vehicle C, which allows a viewer DR to view a first display image VI and a second display image RI represented by display lights L11 and L22, and comprises display units 12b and 12a that transmit light emitted from a light source and display the first display image VI or the second display image RI, and a control unit 15 that controls the display units 12b and 12a, wherein the control unit 15 performs an image plane display process that causes the first display image VI to be viewed on an oblique image plane having a near and far distance in the front-rear direction of the vehicle C, and the second display image RI to be viewed on an elevation image plane, and a predetermined dynamic display process that, during the image plane display process, dynamically zooms in on a predetermined image VIo corresponding to the first display image VI, and dynamically slides it between the far-focus side and the near-focus side as seen from the viewer DR.
[0007] According to the present invention, it is possible to provide a vehicle display device that can reduce the difficulty for the viewer to adjust their focus during zoom display when displaying an image on an oblique image plane.
[0008] A diagram showing the configuration of a head-up display device according to one embodiment of the present invention. A functional block diagram showing the functional configuration of the control unit in the head-up display device. An explanatory diagram showing the contents of the zoom display processing and slide display processing in the dynamic processing unit. An explanatory diagram specifically showing the flow of zoom in and slide in. An explanatory diagram specifically showing the flow of zoom out and slide out. An explanatory diagram showing a comparative example in which zoom in from the center of the driver's field of view. An explanatory diagram showing the contents of the zoom display processing and slide display processing in the dynamic processing unit in a modified example in which slide in and slide out based on the upper edge of the field of view. An explanatory diagram showing the contents of the zoom display processing and slide display processing in the dynamic processing unit in a modified example in which virtual image display on an oblique image plane and virtual image display on an vertical image plane are switched. An explanatory diagram showing the contents of the zoom display processing and slide display processing in the dynamic processing unit in a modified example in which virtual image display on an oblique image plane and virtual image display on an vertical image plane are performed simultaneously.
[0009] One embodiment of the present invention will be described with reference to the drawings.
[0010] Figure 1 is a diagram showing the configuration of a head-up display device (hereinafter referred to as HUD device), which is a vehicle display device according to this embodiment. In Figure 1, the HUD device 1 has a first PGU 10b having a first light source 11b that emits light in the visible wavelength range, and a first display unit 12b that transmits the light emitted by the first light source 11b and displays a virtual image VI (first display image) of a display image formed in front of the driver DR (viewer), and a second light source 11a that emits light in the visible wavelength range, and a second display unit that transmits the light emitted by the second light source 11a and displays a real image RI (second display image) of a display image formed in front of the driver DR. The device comprises a second PGU 10a having a display unit 12a, a reflector 13 that reflects a first display light L22 representing a display image (first display image) displayed on the first display unit 12b and a second display light L11 representing a display image (second display image) displayed on the second display unit 12a toward a windshield WS (light-transmitting member), and a control unit 15 that controls the display content in the first display unit 12b and the second display unit 12a, and controls the switching between the first PGU 10b and the second PGU 10a, etc., and these are housed in a housing 16. The housing 16 is provided with an opening 17 (emission port) from which the second display light L11 and the first display light L22 are emitted, and a cover glass 18 for protecting the inside is placed in the opening 17. The first display unit 12b and the second display unit 12a are examples of display units, and the first light source 11b and the second light source 11a are examples of light sources.
[0011] Furthermore, as shown in Figure 1, the control unit 15 may be configured to control the first PGU 10b and the second PGU 10a with a single control unit 15, or the first PGU 10b and the second PGU 10a may each have their own control unit, and the control unit 15 may be configured to control these individual control units in coordination with each other.
[0012] <Display Light> The HUD device 1 is positioned below the windshield WS of the vehicle C (for example, inside the instrument panel) and emits a first display light L22 and a second display light L11, projecting them onto the windshield WS. The first display light L22 is generated by a first light source 11b and a first display unit 12b inside the HUD device 1, and the second display light L11 is generated by a second light source 11a and a second display unit 12a inside the HUD device 1. The first display light L22 emitted from the first display unit 12b and the second display light L11 emitted from the second display unit 12a travel through the reflector 13 and are emitted through the opening 17 of the housing 16 and through the cover glass 18. The driver DR of vehicle C can see the real image RI on the near side of the windshield WS by viewing the second display light L11 reflected on the windshield WS (real image display state), and can also see the virtual image VI on the far side of the windshield WS by viewing the first display light L22 reflected on the windshield WS (virtual image display state).
[0013] <Virtual Image and Real Image> In Figure 1, the virtual image VI displays information that is highly necessary to draw the attention of the driver DR, such as vehicle information like the speed and engine RPM of vehicle C, route guidance displays such as turn-by-turn directions and maps, blind spot indicators, and warning displays such as speed limit exceeding warnings, on the other side of the windshield WS from the driver DR's perspective. In Figure 1, the real image RI displays entertainment content, assistants or agents that support the driver DR, and characters representing them, on the front side of the windshield WS from the driver DR's perspective. Both the virtual image VI and the real image RI include not only the text and icons that represent this information, but also a background, which in a plan view from the driver DR's perspective appears roughly rectangular.
[0014] <PGU> In the second PGU 10a, the second light source 11a is, for example, a light-emitting diode mounted on a wiring board that emits light in the visible wavelength range and emits white light. The second display unit 12a is located on the aperture 17 side along the optical path from the second light source 11a and has a TFT-type second display element (not shown in Figure 1) that forms a second display light L11 representing an arbitrary image according to a control signal sent from the control unit 15.
[0015] In the first PGU 10b, the first light source 11b is, for example, a light-emitting diode mounted on a wiring board that emits light in the visible wavelength range and emits white light. The first display unit 12b is located on the aperture 17 side along the optical path from the first light source 11b and has a TFT-type first display element (not shown in Figure 1) that forms a first display light L22 representing an arbitrary image according to a control signal sent from the control unit 15.
[0016] In addition, in the first PGU 10b and the second PGU 10a, optical components such as condenser lenses, lenticular lenses, diffusers, and polarizers may be placed at any position downstream of the first light source 11b and the second light source 11a, respectively.
[0017] <Reflective section> In Figure 1, the reflective section 13 includes a second correcting mirror 1310 that reflects the second display light L11 emitted from the second display section 12a toward the first correcting mirror 1320, a first correcting mirror 1320 that reflects the second display light L11 emitted from the second correcting mirror 1310 toward the concave mirror 1330, and a concave mirror 1330 that receives the second display light L11 reflected and folded back by the second correcting mirror 1310 and the first correcting mirror 1320, as well as the first display light L22 that has passed through the first correcting mirror 1320, and reflects it toward the opening 17.
[0018] <Correcting Mirror and Concave Mirror> The first correcting mirror 1320 and the second correcting mirror 1310 have mirror surfaces and are complex free-form shapes to correct distortion of the image seen by the driver (DR). The first correcting mirror 1320 is, for example, a half-mirror and transmits the first display light L22 that represents the virtual image VI displayed on the first display unit 12b. The first display light L22 that has passed through the first correcting mirror 1320 is then incident on the concave mirror 1330. The concave mirror 1330 is rotatably installed and rotates to match the position of the driver's (DR) eyes, freely changing the emission direction of the second display light L11 and the first display light L22, and adjusting the position of the image. In this embodiment, the angle of the display surface is made different when the second display light L11 displays the real image RI and when the first display light L22 displays the virtual image VI. In other words, the driver DR is shown a virtual image VI on an oblique image plane with perspective in the longitudinal direction of the vehicle C, and a real image RI on an upright image plane. Specifically, as shown in Figure 1, the virtual image VI is displayed as if inclined with respect to the road surface, and the real image RI is displayed in a nearly perpendicular position to the road surface. In this embodiment, by adjusting the rotational drive of the concave mirror 1330, it is possible to display the images at angles suitable for the real image RI and the virtual image VI, respectively (see also Figure 2 described later).
[0019] The second corrector mirror 1310 is positioned along the optical path of the second display light L11, closer to the aperture 17 than the second PGU 10a, and closer to the second PGU 10a than the second optical focus F1 of the imaging optical system including the windshield WS, the first corrector mirror 1320, and the concave mirror 1330. The first display unit 12b of the first PGU 10b is positioned along the optical path of the first display light L22, closer to the aperture 17 than the position of the first optical focus F2 of the imaging optical system including the windshield WS and the concave mirror 1330. The position of the first display unit 12b is outside the focal length of the optical system when the first corrector mirror 1320, the concave mirror 1330, and the windshield WS are considered as a single optical system. The position of the second display unit 12a is inside the focal length of the optical system (in this disclosure, between the second corrector 1310 and the first corrector 1320) when the first corrector 1320, the second corrector 1310, the concave mirror 1330, and the windshield WS are considered as a single optical system.
[0020] With this configuration, when the second light source 11a is lit, i.e., when the second PGU 10a is ON, the second display light L11 emitted from the second PGU 10a is reflected by the second correcting mirror 1310, the first correcting mirror 1320, the concave mirror 1330, and the windshield WS, allowing the driver DR to see a real image RI on the inside of the vehicle with the windshield WS in between. Also, when the first light source 11b is lit, i.e., when the first PGU 10b is ON, the first display light L22 emitted from the first PGU 10b passes through the first correcting mirror 1320 and is reflected by the concave mirror 1330 and the windshield WS, allowing the driver DR to see a virtual image VI on the outside of the vehicle with the windshield WS in between.
[0021] In reality, countless rays of light are emitted from the first display unit 12b and the second display unit 12a. However, for the sake of simplicity, the light emitted from the center of each of the first display unit 12b and the second display unit 12a, passing through the center of the eye box, will be referred to as representative rays and indicated by the symbols L11 and L22. In Figure 1, the representative rays emitted from the center of the first display unit 12b and the second display unit 12a are shown as solid lines, the rays emitted from the upper ends of the first display unit 12b and the second display unit 12a are shown as dashed lines, and the rays emitted from the lower ends of the first display unit 12b and the second display unit 12a are shown as double-dash lines.
[0022] <Control Unit> The control unit 15 is a computer equipped with a CPU that executes various programs stored in advance while utilizing the temporary storage function of the memory, and a memory consisting of a storage device equipped with RAM and ROM. The control unit 15 controls at least the first PGU 10b and the second PGU 10a in coordination, and performs switching control between the real image RI and the virtual image VI by turning the first light source 11b on / off and the second light source 11a on / off, control of the display content of the first display unit 12b, control of the display content of the second display unit 12a, and so on.
[0023] <Functional Configuration of the Control Unit> Figure 2 is a functional block diagram showing the functional configuration of the control unit 15 in the HUD device 1 according to this embodiment. The control unit 15 comprises an image surface display processing unit 22 and a display control unit 23.
[0024] The image plane display processing unit 22 switches from the display state of the virtual image VI to the display state of the real image RI (i.e., turns OFF the first PGU 10b and ON the second PGU 10a) or switches from the display state of the real image RI to the display state of the virtual image VI (i.e., turns OFF the second PGU 10a and ON the first PGU 10b) based on an appropriate trigger. At this time, the image plane display processing unit 22 also adjusts the rotational drive of the concave mirror 1330 as described above, so that the driver DR can see the virtual image VI on the aforementioned oblique image plane which has a sense of distance in the front-rear direction of the vehicle C (in detail, a plane with an inclination such that the upper end is in the background and the lower end is in the foreground; see Figure 1). The image plane display processing unit 22 also makes the driver DR see the real image RI on the aforementioned vertical image plane (in detail, a plane with almost no inclination which is almost vertical; see Figure 1). As an example of the above trigger, the image display processing unit 22 displays the virtual image VI when the vehicle C is in manual driving mode, where the driver DR is operating the vehicle, and displays the real image RI when the vehicle C is in automatic driving mode, where the computer is operating the vehicle automatically. In addition to switching driving modes as described above, the above trigger may also be triggered when the driver DR operates a switch, when the vehicle enters a highway or general road, or when the vehicle is parked, stopped, or driving. The above processing performed by the image display processing unit 22 is an example of image display processing.
[0025] The display control unit 23 controls the display content of the first display unit 12b and the second display unit 12a based on information input from various devices 30, including memory. Specifically, the display control unit 23 issues control signals to the first display unit 12b and the second display unit 12a to generate light representing a figure of an arbitrary shape, based on information sent from various devices 30, such as a vehicle speed sensor, navigation device, RADAR (Radio Detection and Ranging), LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), and content information pre-registered in memory. The first PGU 10b and the second PGU 10a then display the desired display image, respectively.
[0026] The dynamic processing unit 24 will be described later.
[0027] <Processing details of the dynamic processing unit> The characteristic of this embodiment lies in the processing details of the dynamic processing unit 24. When the image plane display processing unit 22 switches between the real image RI and the virtual image VI, the dynamic processing unit 24 dynamically zooms and displays a rectangular image (a predetermined image; described later) corresponding to the virtual image VI. At the same time, the dynamic processing unit 24 dynamically slides the rectangular image between the far-focus side and the near-focus side as seen from the driver DR.
[0028] The processing details in the dynamic processing unit 24 described above will be explained with reference to Figures 3(a) to (c).
[0029] <Behavior when switching from real image display to virtual image display> First, Figure 3(a) shows the state when the driver DR is seated in the seat 50 provided in the vehicle C, and the image surface display processing unit 22 switches from the display state of the real image RI to the display state of the virtual image VI. At that time, in this embodiment, when switching from the display state of the real image RI to the display state of the virtual image VI, the dynamic processing unit 24 performs a dynamic display (so-called animation) in which a predetermined image VIo corresponding to the virtual image VI is zoomed in (appears while being enlarged) on the background image BK located within the driver DR's field of view. This process performed by the dynamic processing unit 24 is an example of zoom display processing. Furthermore, in this embodiment, when the dynamic processing unit 24 zooms in on the image VIo, it slides in (appears while moving) the image VIo from the far-focus side (for example, the upper side as seen from the driver DR in the background image BK; see Figure 4 below) to the near-focus side (for example, the lower side as seen from the driver DR in the background image BK; see Figure 4 below). This process executed by the dynamic processing unit 24 is an example of a slide display process.
[0030] Figure 3(b) is a conceptual diagram illustrating the zoom-in and slide-in behavior of image VIo in the background image BK at this time. As shown in the figure, in this example, the center M of image VIo as seen from the driver DR moves downward by a distance LC due to the slide-in described above.
[0031] <Details of Zoom-in + Slide-in Behavior> The zoom-in and slide-in flow shown in Figure 3(b) is illustrated in more detail in Figures 4(a) to (f). Figure 4(a) shows the state immediately after the display of the virtual image VI has switched as described above and the image VIo has appeared in the background image BK. At this time, the center M of the image VIo is located on the far-focus side (upper side in this example) than the center CR of the field of view as seen from the driver DR, as shown in the figure.
[0032] The dynamic processing unit 24 initiates the slide-in process based on the state shown in Figure 4(a), and the size of the image VIo expands by zooming in in the order of Figure 4(b) → Figure 4(c) → Figure 4(d) → Figure 4(e), while the position of the center M shifts towards the near-focal side (downward in this example) by sliding in. Finally, the state shown in Figure 4(f) is reached, in this example, where the position of the center M of the image VIo and the center CR of the field of view approximately coincide. Each figure shows both the position of the horizontal line k passing through the center M of the image VIo in Figure 4(a) and the position of the horizontal line k1 passing through the center M of the image VIo in Figures 4(b) to (f) as the zoom-in and slide-in processes occur. Comparing Figure 4(a) and Figure 4(f), it can be seen that in these two figures, the center M of the image VIo moves downward by a distance LC.
[0033] <Behavior when switching from virtual image display to real image display> In this embodiment, when switching from the display state of the virtual image VI to the display state of the real image RI, the dynamic processing unit 24 performs a dynamic display (so-called animation) in which a predetermined image VIo corresponding to the virtual image VI is zoomed out (disappears while shrinking) in the background image BK located within the field of view of the driver DR. This process performed by the dynamic processing unit 24 is also an example of zoom display processing. Furthermore, in this embodiment, when the dynamic processing unit 24 zooms out the image VIo, the image VIo is slid out (disappears while moving) from the near-focus side (for example, the lower side as seen from the driver DR in the background image BK; see Figure 5 below) to the far-focus side (for example, the upper side as seen from the driver DR viewer in the background image BK; see Figure 5 below). This process performed by the dynamic processing unit 24 is also an example of slide display processing.
[0034] Figure 3(c) above is a conceptual diagram illustrating the zoom-out and slide-out behavior of image VIo in the background image BK at this time. As shown in the figure, in this example, the center M of image VIo as seen from the driver DR moves upward by a distance LC due to the slide-in described above.
[0035] <Details of Zoom-Out + Slide-Out Behavior> The zoom-out and slide-out flow shown in Figure 3(c) is illustrated in more detail in Figures 5(a) to (f). Figure 5(a) shows the state in which the image VIo corresponding to the virtual image VI is displayed in the background image BK before the display state switches from the virtual image VI to the real image RI as described above. The center M of the image VIo at this time approximately coincides with the center CR of the field of view as seen from the driver DR, as shown in the figure.
[0036] The dynamic processing unit 24 initiates the slide-out process based on the state shown in Figure 5(a), and the size of the image VIo decreases as it zooms out in the order of Figure 5(b) → Figure 5(c) → Figure 5(d) → Figure 5(e), while the position of the center M shifts towards the far-focus side (upward in this example) as it slides out. Finally, it reaches the state shown in Figure 5(f), after which the image VIo disappears from the background image BK (or the real image RI appears). In each figure, as with Figures 4(a) to (f), the position of the horizontal line k1 passing through the center M of the image VIo in Figures 5(a) to (e) during the zoom-out and slide-out process, and the position of the horizontal line k passing through the center M of the image VIo in Figure 5(f) are also shown. Comparing Figure 5(a) and Figure 5(f), it can be seen that in these two figures, the center M of the image VIo has moved upward by a distance LC.
[0037] The above-described process performed by the dynamic processing unit 24 is an example of dynamic display processing.
[0038] <Effects of the Embodiment> As described above, in this embodiment, the dynamic processing unit 24 enlarges the size of the image VIo by zooming in, as shown in Figures 4(a) to (f), while the position of the center M moves downward by sliding in. This makes it possible to show the driver (DR) that most of the image VIo on the oblique image plane is moving closer from the back to the front. Also, the dynamic processing unit 24 reduces the size of the image VIo by zooming out, as shown in Figures 5(a) to (f), while the position of the center M moves upward by sliding out. This makes it possible to show the driver (DR) that most of the image VIo on the oblique image plane is moving further away from the front to the back.
[0039] The effects of this embodiment will be explained in more detail using comparative examples. Figures 6(a) to 6(f) are comparative examples showing the case where the display is switched from the real image RI display state to the virtual image VI display state, and zoomed in from the center of the driver DR's field of view, and correspond to Figures 4(a) to 4(f) above.
[0040] Figure 6(a), like Figure 4(a), shows the state immediately after the virtual image VI is displayed and the image VIo appears in the background image BK. The center M of image VIo coincides with the center CR of the field of view as seen by the driver DR. In this comparative example, zooming in begins from the state shown in Figure 6(a), and the size of image VIo increases by zooming in in the order of Figure 6(b) → Figure 6(c) → Figure 6(d) → Figure 6(e). At this time, no sliding occurs as in the above embodiment, and the position of the center M of image VIo always coincides with the center CR of the field of view. Finally, the state shown in Figure 6(f) is reached.
[0041] In the case of this comparative example, when such a simple zoom-in process is performed, the virtual image VIo exists on the oblique image plane as described above. As a result, from the driver's (DR) perspective, the upper half VIu of the image VIo, which increases in size to appear closer, appears to recede into the distance, making it difficult for the driver (DR) to adjust their focus.
[0042] In contrast, in this embodiment, unlike the comparative example described above, as shown in Figures 4(a) to 4(f), the image VIo is slid from top to bottom within the driver's (DR) field of view, and the size is increased by zooming in in such a way that the lower portion of the image VIo is significantly larger (downward) than the upper portion. That is, as can be seen by comparing Figure 4(a) and Figure 4(f), the upward expansion dimension LU of the upper portion of the image VIo from the horizontal line k passing through the center M of the initial image VIo shown in Figure 4(a) is relatively small, while the downward expansion dimension LD of the lower portion of the image VIo is considerably larger. As a result, the driver (DR) can be shown that most of the image VIo on the oblique image plane is approaching from the back to the front. Similarly, in this embodiment, as shown in Figures 5(a) to 5(f), the image VIO is slid from bottom to top within the driver's (DR) field of view, and the size is reduced by zooming out, with the lower portion of the image VIO shrinking (rising) significantly more than the upper portion. That is, as can be seen by comparing Figure 5(a) and Figure 5(f), the downward reduction dimension LU of the upper portion of the image VIO (the dimension from the center M of the image VIO in Figure 5(f) to the position of the horizontal line k passing through the center M of the image VIO) is relatively small from the state in Figure 5(a) to the state in Figure 5(f), while the upward reduction dimension LD of the lower portion of the image VIO (the dimension from the center M of the image VIO in Figure 5(f) to the position of the horizontal line k passing through the center M of the image VIO) is considerably large. As a result, the driver (DR) can see most of the image VIO on the oblique image plane as if it is approaching from the back to the front.
[0043] As a result of the above, this embodiment makes it easier to adjust the focus of the viewer's DR in zoom display.
[0044] Note that, either only the zoom-in + slide-in process shown in FIGS. 3(b) and 4(a) to 4(f) or only the zoom-out + slide-out process shown in FIGS. 3(c) and 5(a) to 5(f) may be executed. Also, although detailed description is omitted, the dynamic processing unit 24 may perform dynamic display (animation) using a predetermined image corresponding to the real image RI in the same manner as described above in the display state of the real image RI. However, in this case, since the real image RI is an elevation image plane, a zoom-in that increases the size from the center of the driver DR's field of view is performed in the same manner as in the comparative example shown in FIG. 6 above. Furthermore, for the zoom-out, the size may be decreased so as to move toward the center of the driver DR's field of view.
[0045] In particular, in the present embodiment, the dynamic processing unit 24 starts the slide-in with reference to a position on the telecentric side rather than the center of the field of view as seen from the driver DR (see FIG. 4(a)). That is, unlike the case of performing a zoom-in of the image VIo from the center of the field of view as in the comparative example of FIG. 6 above, the image VIo can be surely slide-moved downward from the upper part in the driver DR's field of view. Thereby, the size can be increased in such a way that the lower part of the image VIo is lowered more.
[0046] In particular, in the present embodiment, the dynamic processing unit 24 ends the slide-out with reference to a position on the telecentric side rather than the center of the field of view as seen from the driver DR (see FIG. 5(f)). That is, unlike the case of performing a zoom-out of the image VIo toward the center of the field of view, the image VIo can be surely slide-moved downward from the lower side toward the upper part in the driver DR's field of view. Thereby, the size can be decreased in such a way that the lower part of the image VIo is raised more.
[0047] Note that the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist and technical idea thereof. Hereinafter, such modification examples will be described in order.
[0048] (1) When sliding in and out based on the upper end of the field of view The processing content executed by the dynamic processing unit 24 in this modification example will be described with reference to FIGS. 7(a), 7(b), and 7(c) corresponding to FIGS. 3(a), 3(b), and 3(c) respectively above.
[0049] FIG. 7(a) represents a state where, similar to FIG. 3(a) above, with the driver DR seated on the seat 50, the display state has switched from the real image RI to the virtual image VI by the image plane display processing unit 22.
[0050] Also in this modification example, similar to the above embodiment, when the dynamic processing unit 24 zooms in on the image VIo, the image VIo is slid in from the telephoto side toward the wide-angle side. FIG. 7(b) is a conceptual diagram schematically showing the zoom-in and slide-in behavior of the image VIo in the background image BK at this time. As shown in the figure, also in this modification example, the center M of the image VIo as seen from the driver DR moves downward by a distance LC due to the slide-in. However, in this modification example, the slide-in is started based on the position (upper end) of the image VIo that is farthest from the driver DR.
[0051] As a result, as shown in the figure, the area of the upper part of the initial image VIo above the center M is not enlarged at all, and only the area of the lower part of the initial image VIo below the center M is enlarged significantly (lowered) to increase the size and zoom in. Also, as a result, the upper edge position of the image VIo continues to move downward constantly during the above zoom-in. As a result of these, it is possible to show all of the image VIo on the oblique image plane to the driver DR as approaching from the back side to the front side. In particular, since the zoom-in display starts from the position closest to the actual scene located behind as seen from the driver DR, there is also an effect that it is easier to surely adjust the focus of the viewer DR.
[0052] In this modified example, as in the above embodiment, when the dynamic processing unit 24 zooms out the image VIO, it slides the image VIO out from the near-focus side to the far-focus side. Figure 7(c) is a conceptual diagram illustrating the zoom-out and slide-out behavior of the image VIO in the background image BK at this time. As shown in the figure, in this modified example as well, the center M of the image VIO as seen from the driver DR moves upward by a distance LC due to the slide-out, but in this modified example, the slide-out is terminated based on the position (upper end) of the image VIO that is furthest from the driver DR.
[0053] As a result, as shown in the diagram, the area above the center M of the final image VIO does not shrink at all, while only the area below the center M of the image VIO shrinks significantly (rises), thus reducing its size and zooming out. Furthermore, the upper edge of the image VIO continues to rise upwards throughout the zoom-out process. As a result, the driver DR can see the entire image VIO on the oblique image plane as receding from the foreground to the background. In particular, since the zoom-out display ends towards the position closest to the actual scene located behind the driver DR, it also has the effect of making it easier for the viewer DR to adjust their focus.
[0054] (2) When switching between displaying a virtual image on an oblique image plane and displaying a virtual image on an elevation image plane, in the above embodiment and modified example (1), the image plane display processing unit 22 made the driver DR view the virtual image VI on the oblique image plane and the real image RI on the elevation image plane, but is not limited to this. That is, in this modified example, using a known appropriate method, as shown in Figure 8(a) corresponding to Figures 3(a) and 7(a), the image plane display processing unit 22 makes the driver DR view the virtual image VI (first display image in this modified example) on an oblique image plane having a near and far distance in the front-rear direction of the vehicle C, and makes the virtual image VI' (second display image in this modified example) on the elevation image plane.
[0055] In this modified example, although a detailed explanation is omitted, the image plane display processing unit 22 can switch from the display state of virtual image VI to the display state of virtual image VI', or from the display state of virtual image VI' to the display state of virtual image VI, based on the aforementioned trigger. At this time, as described above, the image plane display processing unit 22 allows the driver DR to view the virtual image VI on an oblique image plane (a plane with an inclination such that the upper end is in the background and the lower end is in the foreground; see Figure 8(a)) which has a near-far distance in the front-rear direction of the vehicle C, and allows the driver to view the virtual image VI' on an elevation image plane (a plane with almost no inclination and a nearly vertical orientation; see Figure 8(a)). The above processing performed by the image plane display processing unit 22 is an example of the image plane display processing in this modified example.
[0056] In this modified example, when switching from the display state of virtual image VI' to the display state of virtual image VI, the dynamic processing unit 24 performs the same zoom-in of image VIo corresponding to virtual image VI as described above (an example of zoom display processing in this modified example), and when zooming in, the image VIo is slid in from the far-focus side to the near-focus side (an example of slide display processing in this modified example). Also, when switching from the display state of virtual image VI to the display state of virtual image VI', the dynamic processing unit 24 performs the same zoom-out of image VIo corresponding to virtual image VI as described above (an example of zoom display processing in this modified example), and when zooming out, the image VIo is slid out from the near-focus side to the far-focus side (an example of slide display processing in this modified example).
[0057] Furthermore, a characteristic of this modified version is that, as described above, when switching from the display state of virtual image VI' to the display state of virtual image VI, when virtual image VI' disappears before it appears in the driver's field of view (DR) to begin zooming in, a zoom-out is performed, as shown in Figure 8(c), in which the size of a predetermined image VIo' corresponding to virtual image VI' is reduced while its center M is aligned with the center CR of the driver's field of view (CR). Similarly, when switching from the display state of virtual image VI to the display state of virtual image VI', when virtual image VI' reappears after it has finished zooming out and disappeared from the field of view, a zoom-in is performed, as shown in Figure 8(b), in which the size of a predetermined image VIo' corresponding to virtual image VI' is increased while its center M is aligned with the center CR of the driver's field of view (CR).
[0058] In this modified example, the same effects as in the above embodiment can be obtained with respect to the virtual image VI displayed on the oblique image plane.
[0059] (3) When displaying a virtual image on an oblique image plane and a virtual image on an elevation image plane simultaneously, that is, in this modified example, by a known appropriate method, as shown in Figure 9(a) corresponding to Figure 8(a), the image plane display processing unit 22 allows the driver DR to view the virtual image VI (the first display image in this modified example) on an oblique image plane that has a near and far distance in the front-rear direction of the vehicle C, while simultaneously allowing the driver to view the virtual image VI'' (the second display image in this modified example) on an elevation image plane.
[0060] In this modified example, a detailed explanation is omitted, but as described above, the image plane display processing unit 22 displays the virtual image VI to the driver DR on an oblique image plane (a plane with an inclination such that the upper end is in the background and the lower end is in the foreground, see Figure 9(a)) which has perspective in the front-rear direction of the vehicle C, and displays the virtual image VI'' on an elevation image plane (a plane with almost no inclination and a nearly vertical orientation, see Figure 9(a)). The above processing performed by the image plane display processing unit 22 is an example of the image plane display processing in this modified example.
[0061] In this modified example, the dynamic processing unit 24 performs a zoom-in on the image VIo corresponding to the virtual image VI, as described above (an example of zoom display processing in this modified example), and during the zoom-in, the image VIo is slid in from the far-focus side to the near-focus side (an example of slide display processing in this modified example). Furthermore, the dynamic processing unit 24 performs a zoom-out on the image VIo corresponding to the virtual image VI, as described above (an example of zoom display processing in this modified example), and during the zoom-out, the image VIo is slid out from the near-focus side to the far-focus side (an example of slide display processing in this modified example).
[0062] Furthermore, a characteristic of this modified example is that zoom-in and zoom-out are also performed on the virtual image VI''. That is, when the virtual image VI'' appears, as shown in Figure 9(b), zoom-in is performed to increase the size of the image VI'' while aligning the center M of a predetermined image VIo'' corresponding to the virtual image VI'' with the center CR of the driver's field of view DR. Also, as shown in Figure 9(c), when the virtual image VI'' disappears, zoom-out is performed to decrease the size of the image VIo'' while aligning the center M of a predetermined image VIo'' corresponding to the virtual image VI'' with the center CR of the driver's field of view DR.
[0063] In this modified example, the same effects as in the above embodiment can be obtained with respect to the virtual image VI displayed on the oblique image plane.
[0064] (4) In the above embodiments, the vehicle display device 1 switches the display of the virtual image VI and the real image RI by switching the illumination of two PGUs (first PGU 10b and second PGU 10a), but is not limited to this. For example, one display unit may be configured to include a switching element that switches the polarization of the emitted display light between S-polarization and P-polarization. In this case, the reflecting unit 13 has a first mirror that reflects S-polarized display light and transmits P-polarized display light, a second mirror that reflects the display light that has been transmitted through the first mirror, and a third mirror that reflects the respective display lights reflected by the first and second mirrors and emits them onto the windshield WS. When it is desired that the driver DR see the virtual image VI, the switching element is switched to emit the display light as S-polarized light, and the display image represented by the display light is displayed on the windshield WS by the imaging optical system composed of the first mirror, the third mirror, and the windshield WS. Furthermore, if, for example, it is desired that driver D be able to see the real image RI, the switching element switches to emit the display light as P-polarized light, and the display image represented by the display light is displayed on the windshield WS by the imaging optical system composed of the second mirror, the third mirror, and the windshield WS.
[0065] In addition to the above, the method for switching between displaying the virtual image VI and the real image RI is arbitrary. For example, the distance between the optical focus and the display unit can be changed by sliding the position of one display unit in the direction of the optical axis, thereby switching between displaying the virtual image VI and the real image RI. Alternatively, the axis of the light rays emitted from the display unit can be shifted when displaying the virtual image VI and when displaying the real image RI to form separate optical systems and switch between displaying the virtual image VI and the real image RI.
[0066] Furthermore, if it is desired to further adjust the inclination angle of the virtual image VI and real image RI with respect to the road surface, the display unit may be equipped with a motor that rotates the display unit by pitch with the optical axis direction as the roll axis. By changing the inclination of the display unit with this motor, it may be possible to display a real image RI that appears to be standing perpendicular to the road surface, or a virtual image VI that appears to be tilted relative to the road surface.
[0067] 1 HUD device (vehicle display device) 10a Second PGU 10b First PGU 11a Second light source 11b First light source 12a Second display unit 12b First display unit 13 Reflector 15 Control unit 16 Housing 17 Aperture 18 Cover glass 22 Image plane display processing unit 23 Display control unit 24 Dynamic processing unit 30 Various devices 50 Sheet 1310 Second correcting mirror 1320 First correcting mirror 1330 Concave mirror BK Background image C Vehicle CR Center of field of view DR Driver (viewer) F1 Second optical focus F2 First optical focus k Horizontal line passing through the center of a predetermined image k1 Horizontal line passing through the center of a predetermined image L11 Second display light L22 First display light LC Distance traveled by the center of the image LD Dimension of downward expansion of the lower part of the image LU Upper part of the image is enlarged upwards. M: Center of the image. VI: Virtual image (first display image). VIo: Image (predetermined image). VI': Virtual image (second display image). VIo': Image (predetermined image). VI'': Virtual image (second display image). VIo'': Image (predetermined image). VIu: Upper half of the image. RI: Real image (second display image). WS: Windshield (translucent material).
Claims
1. A vehicle display device installed in a vehicle, which allows a viewer to view a first display image and a second display image represented by a display light, comprising: a display unit that transmits light emitted from a light source and displays the first display image or the second display image; and a control unit that controls the display unit, wherein the control unit performs an image plane display process that causes the first display image to be viewed on an oblique image plane having a near and far distance in the front-rear direction of the vehicle, and the second display image to be viewed on an upright image plane; and a predetermined dynamic display process that, during the image plane display process, dynamically zooms in on a predetermined image corresponding to the first display image and dynamically slides it between the far-focus side and the near-focus side as seen from the viewer.
2. The vehicle display device according to claim 1, characterized in that the dynamic display processing includes a zoom display processing which zooms in on the predetermined image when the first display image is made visible on the oblique image plane by the image plane display processing, and a slide display processing which slides in the predetermined image from the far-focus side to the near-focus side when the zoom is performed by the zoom display processing.
3. The vehicle display device according to claim 2, characterized in that the control unit starts the slide-in process with reference to a position on the far-focus side of the center of the field of view as seen by the viewer.
4. The vehicle display device according to claim 3, characterized in that the control unit starts the slide-in process using the position of the predetermined image furthest from the viewer as a reference.
5. The vehicle display device according to any one of claims 2 to 4, wherein the control unit further zooms out the predetermined image when the second display image is made visible on the vertical image plane by the image plane display process, and further slides out the predetermined image from the near-focus side to the far-focus side when the zoom is performed by the zoom display process.
6. The vehicle display device according to claim 5, characterized in that the control unit terminates the slide-out in the zoom display process with reference to a position on the far-focus side of the center of the field of view as seen by the viewer.
7. The vehicle display device according to claim 6, characterized in that the control unit terminates the slide-out in the zoom display process based on the position of the predetermined image furthest from the viewer.
8. The vehicle display device according to claim 1, characterized in that the first display image is a virtual image and the second display image is a real image.
9. The vehicle display device according to claim 8, comprising: a light source that emits light that becomes a virtual image or a real image; a display unit that displays the virtual image or the real image based on the light emitted by the light source; and a reflecting unit that reflects a first display light or a second display light, each representing the virtual image or the real image displayed on the display unit, toward a light-transmitting member of the vehicle, wherein the vehicle display device is a head-up display device that switches between the virtual image represented by the first display light and the real image represented by the second display light for the viewer to see.