Vehicle display device

Abstract

To improve viewer visibility by adjusting a light quantity in each display when performing displays by switching between the inside and outside of a vehicle.SOLUTION: A vehicle display device 1 that allows visual recognition of a virtual image VI and a real image RI of a display image shown by display light L by emitting the display light L toward a windshield WS through an opening 18, includes: a display section 12 which is provided with a display element 121, transmits light emitted from a light source 11 and displays a display image; a reflecting section 13 which reflects, toward the windshield WS, light representing the display image displayed on the display section 12; and a control section 15. The control section 15 executes light-quantity control processing to control the light quantity of the light source 11 such that a real-image display luminance setting for allowing visual recognition of the real image RI and a virtual-image display luminance setting for allowing visual recognition of the virtual image VI have a predetermined luminance difference.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display device for a vehicle that displays a desired image to a viewer. [Background technology]

[0002] A conventional electronic device is known, for example, from Patent Document 1. This electronic device has a cluster display unit and a HUD attached to an instrument panel, determines the vehicle's driving state, and adjusts the focal length of the HUD based on the determination result so that the position of a virtual image of a projected image is near the cluster display unit or in front of the windshield. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6516642 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional electronic devices, the display position of the virtual image is switched between inside and outside the vehicle, so the appearance differs when viewed together with ambient light, and when viewed inside the vehicle, which poses a problem of perceived brightness difference and glare when switching the display position from one display to the other (or when viewing both displays simultaneously).

[0005] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a vehicle display device that improves visibility for the viewer by adjusting the amount of light for each display when switching between displaying inside and outside the vehicle. [Means for solving the problem]

[0006] The present invention provides a vehicle display device 1 that is provided in a vehicle C having a seat for a passenger DR and a translucent member WS, and that emits display light L1, L2 from an emission port 17 toward the translucent member WS, thereby allowing a virtual image VI and a real image RI of the display image represented by the display light L1, L2 to be viewed. The vehicle display device 1 includes a display unit 12 that has a display element, transmits light emitted by a light source 11, and displays the display image, a reflecting unit 13 that reflects light representing the display image displayed on the display unit 12 toward the translucent member WS, and a control unit 15, wherein the control unit 15 executes a light intensity control process (S3, S4, S6, and S7) that controls the light intensity of the light source 11 so that a first display luminance setting when the real image RI is viewed and a second display luminance setting when the virtual image VI is viewed have a predetermined luminance difference from each other. [Effects of the Invention]

[0007] According to the present invention, by adjusting the light amount of the light source, it is possible to allow a vehicle occupant to visually recognize a real image and a virtual image with an appropriate luminance difference. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing a configuration for generating a virtual image in the vehicle display device according to the first embodiment of the present invention. [Figure 2] 1 is a diagram showing a configuration for generating a real image in a vehicle display device according to a first embodiment of the present invention; [Figure 3] 1 is a schematic diagram showing the structure of a light source and a display unit of an HUD device in a vehicle display device according to a first embodiment of the present invention. [Figure 4] 1 is a functional block diagram illustrating a configuration of a control unit of a vehicle display device according to a first embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing brightness settings for daytime ambient light. [Figure 6] FIG. 10 is a diagram showing brightness settings for evening ambient light. [Figure 7] FIG. 10 is a diagram showing brightness settings for ambient light at night. [Figure 8]3 is a diagram showing an example of a change in luminance when switching between real image display and virtual image display in the vehicle display device according to the first embodiment of the present invention. FIG. [Figure 9] 10A and 10B are diagrams showing an example of a change in luminance when switching between real image display and virtual image display in the daytime or evening. [Figure 10] 10A and 10B are diagrams showing an example of a change in luminance when switching between real image display and virtual image display at night. [Figure 11] 5 is a flowchart showing the operation of a control unit in the vehicle display device according to the first embodiment of the present invention. [Figure 12] FIG. 6 is a diagram showing the configuration of a vehicle display device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment of the present invention) The vehicle display device according to this embodiment will be described with reference to Figures 1 to 11. Figure 1 is a diagram showing the configuration when a virtual image is generated in the vehicle display device according to this embodiment, and Figure 2 is a diagram showing the configuration when a real image is generated in the vehicle display device according to this embodiment.

[0010] 1 and 2, a vehicle display device 1 includes a head-up display device (hereinafter referred to as HUD device) 2 and a setting unit 3 that stores setting information used to control the HUD device 2. The HUD device 2 includes a light source 11 that emits white light, for example, a light-emitting diode (LED) that emits light in the visible wavelength range and is mounted on a wiring board, a display unit 12 that generates an image using the light incident from the light source 11 and displays the image by switching the polarization of the emitted light between a first polarization and a second polarization that are different from each other, a reflecting unit 13 that reflects display light L (display light L1 that represents a virtual image VI in the case of FIG. 1, and display light L2 that represents a real image RI in the case of FIG. 2) that represents the display image displayed on the display unit 12 toward a windshield WS (a light-transmitting member), and a control unit 15 that controls the display content of the display unit 12, controls switching between the first polarization and the second polarization, and controls brightness by adjusting the amount of light emitted by the light source 11, and these are housed in a housing 16. The housing 16 is provided with an opening 17 (exit port) through which the display light L is emitted, and a cover glass 18 for protecting the inside is disposed in the opening 17. The window shield WS is an example of a light-emitting member, and the opening 17 is an example of an exit port.

[0011] The HUD device 2 is disposed below the windshield WS of the vehicle C (for example, inside the instrument panel), and emits display light L (L1, L2) and projects it onto the windshield WS. The display light L is generated by a light source 11 and a display unit 12 inside the HUD device 2. The display light L emitted from the display unit 12 travels along a reflecting unit 13 and is emitted from an opening 17 in a housing 16 through a cover glass 18. By viewing the display light L reflected by the windshield WS, the driver DR (passenger) of the vehicle C can view a virtual image VI on the far side of the windshield WS as shown in FIG. 1 and a real image RI on the near side as shown in FIG. 2.

[0012] The virtual image VI shown in FIG. 1 displays information that is highly necessary to draw the driver DR's attention, such as vehicle information such as the speed and engine RPM of the 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 as viewed from the driver DR. The real image RI shown in FIG. 2 displays, for example, entertainment content, assistants and agents supporting the driver DR, and characters representing them, on the front side of the windshield WS as viewed from the driver DR. These displays provide a driving environment that reduces the need to move the driver's viewpoint and adjust the focal length of the eyes. The virtual image VI and real image RI include background portions as well as characters and icons indicating this information, and are, for example, approximately rectangular in shape when viewed in a planar view from the driver DR.

[0013] Here, the configurations of the light source 11 and the display unit 12 will be described. Fig. 3 is a schematic diagram showing the structures of the light source 11 and the display unit 12 of the HUD device 2 in the vehicle display device 1 according to this embodiment. As shown in Fig. 3, the display unit 12 is provided closer to the light source 11 as viewed from the light source toward the exit along the optical path. The display unit 12 includes, for example, a TFT (Thin Film Transistor) display element 121, and a switching element 122 that is provided closer to the exit along the optical path than the display element 121 and switches the polarization of the emitted display light L between first and second polarized lights that are different from each other.

[0014] For example, the first polarized light may be S polarized light and the second polarized light may be P polarized light, or vice versa. In addition, the first polarized light and the second polarized light are not limited to S polarized light and P polarized light, as long as the polarization angles of the first polarized light and the second polarized light are different, and it is desirable that the polarization angles differ by at least 22.5 degrees, for example.

[0015] Furthermore, as shown in Figures 1 and 2, it is desirable that the display unit 12 be arranged at an angle with respect to the axial direction of the light rays of the display light L in order to eliminate stray light (light leaking from the light source 11) and external light (light entering from outside) from the optical path of the display light L.

[0016] The light source 11 is connected to a real image luminance adjuster 54a and a virtual image luminance adjuster 54b (described later in FIG. 4), and the light intensity is adjusted so that a predetermined luminance difference is achieved between a real image display luminance setting value (first display luminance setting) when the driver DR is to view a real image RI and a virtual image display luminance setting value (second display luminance setting) when the driver DR is to view a virtual image VI. The display element 121 generates light representing a figure of any shape in accordance with a signal sent from the control unit 15. The switching element 122 extracts only light rays of a specific polarization, specifically the first polarization or second polarization described above, from the light rays emitted from the display element 121 and switches between them. The switching element 122 is connected to a switching control unit 22 (described later in FIG. 4), and switches the polarization in accordance with a signal sent from the switching control unit 22.

[0017] The switching of polarization by the switching element 122 may be performed by electrical processing, or the polarization may be switched by arranging a polarizing plate or a wavelength plate on the exit side of the display element 121 and physically rotating the central axis at a predetermined angle with the optical axis direction as the central axis. In either case, the switching of polarization is performed under the control of the switching control unit 22.

[0018] 1 and 2, the reflecting unit 13 includes a first mirror 131, a second mirror 132, and a third mirror 133, each of which is a concave mirror. The first mirror 131 reflects display light L1 (first light ray) having a first polarization and transmits display light L2 (second light ray) having a second polarization. The second mirror 132 reflects display light L2 (second light ray) that transmits through the first mirror 131. The display lights L1 and L2 reflected by the first mirror 131 and the second mirror 132 are guided to the third mirror 133, reflected by the third mirror 133, and emitted to the windshield WS, allowing the driver DR to view the respective display images. The display light L1 is an example of a first light ray, and the display light L2 is an example of a second light ray.

[0019] In reality, countless rays of light are emitted from the display unit 12, but for ease of explanation, the light emitted from the center of the display unit 12 and passing through the center of the eyebox is referred to as a representative ray and is indicated by the symbol L. In addition, in Figures 1 and 2, as well as Figure 12 described below, the representative ray emitted from the center of the display unit 12 is indicated by a solid line, the ray emitted from the upper end of the display unit 12 is indicated by a dashed line, and the ray emitted from the lower end of the display unit 12 is indicated by a dashed line.

[0020] 2, since the first mirror 131 is a mirror that transmits the display light L2, the display light L2 reflected by the second mirror 132 can also be transmitted from the rear side where the second mirror 132 is located to the front side. That is, as shown in FIG. 2, the display light L2 that has transmitted through the first mirror 131 is reflected by the second mirror 132, transmitted through the first mirror 131 again, and guided to the third mirror 133. This makes it possible to arrange the second mirror 132 close to the rear side of the first mirror 131, thereby preventing the housing 16 from becoming large.

[0021] Here, for example, the first polarized light is S polarized light (S polarized light relative to the first mirror 131), the second polarized light is P polarized light (P polarized light relative to the first mirror 131), the first mirror 131 is a mirror that reflects S polarized light toward the first mirror 131 and transmits P polarized light, and the second mirror 132 is a mirror that reflects P polarized light toward the first mirror 131 and transmits S polarized light. In this configuration, the display light L1, which is S polarized light, is reflected by the first mirror 131 and guided to the third mirror 133. The display light L2, which is P polarized light, transmits the first mirror 131, is reflected by the second mirror 132, and is guided to the third mirror 133. By setting such a configuration of the reflector 13 and the polarizations of the display lights L1 and L2, it is possible for the display lights L1 and L2 to generate different display images.

[0022] A display image represented by display light L1 in Fig. 1 and a display image represented by display light L2 in Fig. 2 will be specifically described. As shown in Fig. 2, the second mirror 132 is a mirror having a concave shape, and has a radius of curvature such that, when the second mirror 132, the third mirror 133, and the windshield WS are considered as a single optical system, the second mirror 132 is in a second state in which the position of the display unit 12 is outside the focal length of the optical system (on the front side with respect to the display light L). As a result, when light of the second polarization is emitted, the light reflected by the second mirror 132, the third mirror 133, and the windshield WS is visually recognized by the driver DR as a real image RI.

[0023] As shown in FIG. 1 , the first mirror 131 also has a concave shape, but has a radius of curvature R1 (R1>R2) larger than the radius of curvature R2 of the second mirror 132. When the first mirror 131, the third mirror 133, and the windshield WS are considered as a single optical system, the radius of curvature is such that the display unit 12 is positioned inside the focal length of the optical system (at the rear end with respect to the display light L) in a first state. This is because, when the radius of curvature of a concave mirror is large, the focal length becomes farther from the mirror, and when the radius of curvature is small, the focal length becomes closer to the mirror. Therefore, the radius of curvature of the first mirror 131, which makes the focal length farther, is larger. As a result, when light of the first polarization is emitted, the light reflected by the first mirror 131, the third mirror 133, and the windshield WS is visually recognized by the driver DR as a virtual image VI. Note that the optical focus is indicated by F in FIGS. 1 and 2 .

[0024] That is, for example, when it is desired that a virtual image VI be viewed from the driver DR on the far side of the windshield WS, the switching element 122 of the display unit 12 switches the display light L to be emitted as display light L1, which is a first polarization, and a display image represented by the display light L1 is displayed on the windshield WS by an imaging optical system composed of the first mirror 131, the third mirror 133, and the windshield WS. Also, when it is desired that a real image RI be viewed from the driver DR on the near side of the windshield WS, the switching element 122 of the display unit 12 switches the display light L to be emitted as display light L2, which is a second polarization, and a display image represented by the display light L2 is displayed on the windshield WS by an imaging optical system composed of the second mirror 132, the third mirror 133, and the windshield WS.

[0025] In Figures 1 and 2, the first mirror 131 is described as a mirror having a concave shape, but if the first mirror 131, the third mirror 133, and the windshield WS are considered to be a single optical system, and the position of the display unit 12 satisfies the condition that it is located inside the focal length of that optical system (on the rear side with respect to the display light L), then the first mirror 131 may be a mirror having a flat shape or a mirror having a convex shape.

[0026] In addition, although the third mirror 133 is depicted in Figures 1 and 2 as a mirror having a concave shape, it may also be a mirror having a flat shape or a mirror having a convex shape, and since the display lights L1 and L2 are irradiated via the same third mirror 133 whether a virtual image VI or a real image RI is displayed, the third mirror 133 may have a shape without magnification.

[0027] The control unit 15 at least controls the display content on the display unit 12, controls switching between the first polarized light and the second polarized light, and controls brightness by adjusting the amount of light emitted by the light source 11. Fig. 4 is a functional block diagram for explaining the configuration of the control unit 15 of the vehicle display device 1 according to this embodiment. Note that Fig. 4 shows only the configuration directly related to the processing of the control unit 15, and other known configurations are omitted.

[0028] 4, the HUD device 2 includes the above-described control unit 15, light source 11, display unit 12, and reflector 13. The control unit 15 includes a light intensity control unit 54 that controls the light intensity of the light source 11 based on operation information from an operation unit 51 that switches the driving mode of the vehicle C (e.g., automatic driving mode / manual driving mode), display brightness setting information 52 related to the brightness of the virtual image VI and the real image RI that is preset in the setting unit 3, and external information 53 that indicates the surrounding environment of the vehicle C. The control unit 15 also includes a switching control unit 55 that switches the display light L emitted by the display unit 12 between the first polarized light and the second polarized light (i.e., switches between the display state of the virtual image VI and the display state of the real image RI) based on the operation information from the operation unit 51. Furthermore, the control unit 15 includes a display control unit 56 that issues a command to the display unit 12 to generate light representing a figure of any shape based on information sent from various devices 30, such as a vehicle speed sensor, a navigation device, a RADAR (Radio Detecting and Ranging), or a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging).

[0029] The driving modes of the vehicle C include an automatic driving mode and a manual driving mode. For example, in the automatic driving mode, a real image RI is displayed in front of the windshield WS as seen by the driver DR (inside the vehicle), and in the manual driving mode, a virtual image VI is displayed behind the windshield WS as seen by the driver DR (outside the vehicle). That is, when the driving mode is switched from the automatic driving mode to the manual driving mode by the operation unit 51, the switching control unit 55 switches the display light L emitted by the display unit 12 from the second polarized light beam to the first polarized light beam. Conversely, when the driving mode is switched from the manual driving mode to the automatic driving mode by the operation unit 51, the switching control unit 55 switches the display light L emitted by the display unit 12 from the first polarized light beam to the second polarized light beam.

[0030] In addition to switching the driving mode, the polarization state of the display light L may be switched depending on whether ACC (adaptive cruise control) is turned on or off. When the ACC function is on, the switching control unit 55 may switch the display light L emitted by the display unit 12 from the first polarized light beam to the second polarized light beam, and when the ACC function is off, the switching control unit 55 may switch the display light L from the second polarized light beam to the first polarized light beam.

[0031] In the switching process of the switching control unit 55, the appearance differs between the virtual image VI displayed together with the light of the surrounding environment of the vehicle C (hereinafter referred to as ambient light) and the real image RI displayed inside the vehicle. When the position of the visually recognized display image switches between the virtual image VI display and the real image RI display, if both are displayed at the same brightness, the driver DR may perceive a difference in brightness due to the difference between the ambient light and the light inside the vehicle, and the driver DR may find the display image dazzling. This is particularly noticeable when the driver DR simultaneously views the display image and the scenery that falls within the peripheral field of vision of the display image. Therefore, the light intensity control unit 54 adjusts the brightness of the virtual image VI and the real image RI to solve this problem.

[0032] The setting of luminance according to ambient light will be specifically described below. FIG. 5 is a diagram showing the setting of luminance according to ambient light in the daytime, FIG. 6 is a diagram showing the setting of luminance according to ambient light in the evening, and FIG. 7 is a diagram showing the setting of luminance according to ambient light at night. During the daytime, as shown in FIG. 5, the ambient light outside the vehicle is bright, and the interior of the vehicle is equally or slightly dark. In this case, if the virtual image VI and the real image RI are displayed at the same luminance, the driver DR will find the real image RI dazzling. Therefore, the luminance of the virtual image VI, which is viewed together with the ambient light outside the vehicle, is set high, and the luminance of the real image RI, which is viewed inside the vehicle, is set low.

[0033] In the evening, the ambient light outside the vehicle is still bright, making the interior of the vehicle dark, as shown in Figure 6. If the virtual image VI and real image RI are displayed at the same luminance in this case, the driver DR will find the real image RI too dazzling, as in the case of Figure 5. Therefore, the luminance of the virtual image VI, which is viewed together with the ambient light outside the vehicle, is set high, and the luminance of the real image RI, which is viewed inside the vehicle, is set low.

[0034] At night, as shown in Figure 7, the ambient light outside the vehicle is dark, and the interior of the vehicle is bright due to the interior lights. In this case, if the virtual image VI and the real image RI are displayed at the same luminance, the driver DR will find the virtual image VI too dazzling. Therefore, the luminance of the virtual image VI, which is viewed together with the ambient light outside the vehicle, is set low, and the luminance of the real image RI, which is viewed inside the vehicle, is set high.

[0035] That is, appropriate brightness is set for each scene depending on the ambient light outside and inside the vehicle. The setting of the ambient light outside and inside the vehicle may be, for example, manually input by the driver DR, may be set based on information on whether the headlights of the vehicle C are on or off, or may be set based on illuminance information of external light detected by an illuminance sensor provided in the vehicle C. Specifically, for example, when the headlights are not on, it is considered to be daytime or evening, and settings for daytime or evening conditions are applied. When the headlights are on, it is considered to be nighttime, and settings for nighttime conditions are applied. Furthermore, when the illuminance sensor provided in the vehicle C detects brightness equal to or greater than a predetermined illuminance, it is considered to be daytime or evening, and settings for daytime or evening conditions are applied. When it detects brightness less than the predetermined illuminance, it is considered to be nighttime, and settings for nighttime conditions are applied.

[0036] Brightness setting information corresponding to the ambient light outside and inside the vehicle is registered in advance in display brightness setting information 52 shown in Fig. 4. Specifically, as shown in Figs. 5 to 7, the display brightness setting information 52 registers a real image display brightness setting value (first display brightness setting) when the real image RI is to be viewed and a virtual image display brightness setting value (second display brightness setting) when the virtual image VI is to be viewed for each state of ambient light outside and inside the vehicle. When the real image RI is to be displayed, the real image brightness adjustment unit 54a shown in Fig. 4 executes a process of adjusting the light amount of the light source 11 so that the brightness of the real image RI becomes the real image display brightness setting value, and when the virtual image VI is to be displayed, the virtual image brightness adjustment unit 54b executes a process of adjusting the light amount of the light source 11 so that the brightness of the virtual image VI becomes the virtual image display brightness setting value. As a result, the real image RI and the virtual image VI have a predetermined brightness difference from each other.

[0037] For example, in the daytime of Fig. 5 and in the evening of Fig. 6, the virtual image VI viewed together with the ambient light outside the vehicle has a high virtual image display luminance setting value, and the real image RI viewed inside the vehicle has a low real image display luminance setting value. In this state, when the driving mode of the vehicle C is switched from the manual driving mode to the automatic driving mode, and the display of the virtual image VI outside the vehicle is switched to the real image RI inside the vehicle, the real image luminance adjustment unit 54a of the light amount control unit 54 adjusts the luminance of the real image RI to a low value (for example, 500 cd / m) in accordance with the real image display luminance setting value. 2 Conversely, when the driving mode of the vehicle C is switched from the automatic driving mode to the manual driving mode, and accordingly the display of the real image RI inside the vehicle is switched to the virtual image VI outside the vehicle, the virtual image luminance adjustment unit 54b of the light amount control unit 54 adjusts the luminance of the virtual image VI to a high value (for example, 1000 cd / m 2 The high (low) luminance referred to here refers to the relatively higher (brighter) luminance in the relationship between the luminance of the virtual image VI and the luminance of the real image RI, and the relatively lower (darker) luminance.

[0038] 7, for example, the virtual image VI viewed together with the ambient light outside the vehicle has a low virtual image display luminance setting value, and the real image RI viewed inside the vehicle has a high real image display luminance setting value. In this state, when the driving mode of the vehicle C is switched from the manual driving mode to the automatic driving mode, and the display of the virtual image VI outside the vehicle is switched to the real image RI inside the vehicle, the real image luminance adjustment unit 54a of the light amount control unit 54 increases the luminance of the real image RI in accordance with the real image display luminance setting value (for example, 1000 cd / m 2 Conversely, when the driving mode of the vehicle C is switched from the automatic driving mode to the manual driving mode, and accordingly the display of the real image RI inside the vehicle is switched to the virtual image VI outside the vehicle, the virtual image luminance adjustment unit 54b of the light amount control unit 54 adjusts the luminance of the virtual image VI to a low value (for example, 500 cd / m 2 Adjust to a certain extent.

[0039] 8A and 8B are diagrams showing an example of a change in luminance when switching between a real image RI display and a virtual image VI display in the vehicle display device 1 according to this embodiment. Fig. 8A shows an example of a change in luminance when switching from a display state in which the luminance is set low to a display state in which the luminance is set high, and Fig. 8B shows an example of a change in luminance when switching from a display state in which the luminance is set high to a display state in which the luminance is set low. The trigger in Fig. 8 is, for example, a driving mode switching operation or ACC ON / OFF switching information.

[0040] In the daytime and evening cases of Figures 5 and 6 shown above, when switching from virtual image VI display to real image RI display, the luminance setting changes from high to low, resulting in the luminance change shown in parentheses in Figure 8(B). Conversely, when switching from real image RI display to virtual image VI display, the luminance setting changes from low to high, resulting in the luminance change shown in Figure 8(A).

[0041] In the nighttime case shown in Figure 7 above, when switching from virtual image VI display to real image RI display, the luminance setting changes from low to high, resulting in the luminance change shown in parentheses in Figure 8(A). Conversely, when switching from real image RI display to virtual image VI display, the luminance setting changes from high to low, resulting in the luminance change shown in Figure 8(B).

[0042] In this way, the light amount control unit 54 adjusts the luminance when switching from the virtual image VI to the real image RI, and adjusts the luminance when switching from the real image RI to the virtual image VI, depending on the state of the ambient light outside and inside the vehicle. In the vehicle display device 1 according to this embodiment, the luminance change manner is further controlled, thereby enabling the driver DR to more comfortably view the virtual image VI and the real image RI. Specifically, when the real image luminance adjustment unit 54a and the virtual image luminance adjustment unit 54b adjust the light amount of the light source 11, they adjust the light amount of the light source 11 to the real image display luminance setting value and the virtual image display luminance setting value while increasing the luminance over time from a transient luminance setting value that is lower than the real image display luminance setting value and the virtual image display luminance setting value, respectively.

[0043] Fig. 9 shows an example of how luminance changes when switching between real image RI display and virtual image VI display during the day or evening. Fig. 9(A) shows how luminance changes when switching from real image RI display to virtual image VI display, and Fig. 9(B) shows how luminance changes when switching from virtual image VI display to real image RI display.

[0044] 9(A) shows control for switching from a state in which a real image RI having a relatively low luminance is displayed to a state in which a virtual image VI is displayed at the luminance of the virtual image display luminance setting value, which is set relatively high as shown in FIGS. 5 and 6. After receiving a trigger, the virtual image luminance adjustment unit 54b adjusts the light amount of the light source 11 so that the luminance reaches the virtual image display luminance setting value while increasing the luminance over time from a first transient luminance setting value, which is lower than the virtual image display luminance setting value.

[0045] 9(B) shows control for switching from a state in which a virtual image VI with a relatively high luminance is displayed to a state in which a real image RI is displayed at the luminance of the real image display luminance setting value, which is set relatively low as shown in Figures 5 and 6. After receiving a trigger, the real image luminance adjustment unit 54a adjusts the light amount of the light source 11 so that the luminance reaches the real image display luminance setting value while increasing the luminance over time from a second transient luminance setting value, which is lower than the real image display luminance setting value.

[0046] Fig. 10 shows an example of how luminance changes when switching between real image RI display and virtual image VI display at night. Fig. 10(A) shows how luminance changes when switching from real image RI display to virtual image VI display, and Fig. 10(B) shows how luminance changes when switching from virtual image VI display to real image RI display.

[0047] 10(A) shows control for switching from a state in which a real image RI having a relatively high luminance is displayed to a state in which a virtual image VI is displayed at the luminance of the virtual image display luminance setting value, which is set relatively low as shown in Fig. 7. After receiving a trigger, the virtual image luminance adjustment unit 54b adjusts the light amount of the light source 11 so that the luminance reaches the virtual image display luminance setting value while increasing the luminance over time from a second transient luminance setting value, which is lower than the virtual image display luminance setting value.

[0048] 10(B) shows control for switching from a state in which a virtual image VI with a relatively low luminance is displayed to a state in which a real image RI is displayed at the luminance of the real image display luminance setting value, which is set relatively high as shown in Fig. 7. After receiving a trigger, the real image luminance adjustment unit 54a adjusts the light amount of the light source 11 so that the luminance reaches the real image display luminance setting value while increasing the luminance over time from a first transient luminance setting value, which is lower than the real image display luminance setting value.

[0049] 9(A) and 10(B), the first transient luminance setting value is set to a value between the real image display luminance setting value and the virtual image display luminance setting value, but the first transient luminance setting value may be set to the luminance value of the display light L before switching. That is, the luminance may change in the manner shown in FIG. 8(A).

[0050] In addition, in the block diagram of Figure 4, a configuration has been described in which the display brightness setting information 52 is stored in a setting unit 3 outside the HUD device 2 (for example, a storage unit such as a ROM provided in the vehicle C), but the setting unit 3 may also be configured to be provided inside the HUD device 2.

[0051] Next, the operation of the control unit 15 when switching between the virtual image VI display and the real image RI display will be described. Fig. 11 is a flowchart showing the operation of the control unit 15 in the vehicle display device 1 according to this embodiment. First, the control unit 15 acquires, as external information 53, for example, information regarding the on / off state of the headlights, and determines whether the current time is daytime, evening, or nighttime (S1). Note that the process of S1 is not limited to information regarding the state of the headlights, and as described above, illuminance information of external light detected by an illuminance sensor provided in the vehicle C may also be used.

[0052] If it is determined in S1 that it is daytime or evening, it is determined whether the switching of the display light L is a switch from real image RI display to virtual image VI display, or a switch from virtual image VI display to real image RI display (S2). If the switching is from real image RI display to virtual image VI display in S2, the virtual image luminance adjuster 54b of the light amount controller 54 adjusts the light amount of the light source 11 in the change manner of the luminance value shown in Fig. 9(A) (S3) (light amount control process), and the process ends. If the switching is from virtual image VI display to real image RI display in S2, the real image luminance adjuster 54a of the light amount controller 54 adjusts the light amount of the light source 11 in the change manner of the luminance value shown in Fig. 9(B) (S4) (light amount control process), and the process ends.

[0053] If it is determined in S1 that it is nighttime, it is determined whether the switching of the display light L is a switch from real image RI display to virtual image VI display or a switch from virtual image VI display to real image RI display (S5). If the switching is from real image RI display to virtual image VI display in S5, the virtual image luminance adjuster 54b of the light amount controller 54 adjusts the light amount of the light source 11 in the change manner of the luminance value shown in Fig. 10(A) (S6) (light amount control process), and the process ends. If the switching is from virtual image VI display to real image RI display in S5, the real image luminance adjuster 54a of the light amount controller 54 adjusts the light amount of the light source 11 in the change manner of the luminance value shown in Fig. 10(B) (S7) (light amount control process), and the process ends.

[0054] As described above, the vehicular display device 1 according to this embodiment is provided in a vehicle C equipped with a seat for a driver DR and a windshield WS, and emits display light L from an opening 17 toward the windshield WS to allow a virtual image VI and a real image RI of a display image represented by the display light L to be visually recognized. The vehicular display device 1 includes a display element 121, a display unit 12 that transmits light emitted by a light source 11 and displays a display image, a reflecting unit 13 that reflects light representing the display image displayed on the display unit 12 toward the windshield WS, and a control unit 15. Furthermore, the control unit 15 executes a light intensity control process (S3, S4, S6 and S7 in FIG. 11) that controls the light intensity of the light source 11 so that the real image display brightness setting value when the real image RI is viewed and the virtual image display brightness setting value when the virtual image VI is viewed have a predetermined brightness difference from each other. Therefore, an appropriate brightness difference can be set between the brightness of the real image RI, which is normally displayed on the inside of the vehicle, and the brightness of the virtual image VI, which is normally displayed on the outside of the vehicle. This makes it possible to avoid the visual discomfort and glare that can occur when switching between real image RI display and virtual image VI display at the same brightness.

[0055] Furthermore, in the vehicle display device 1 according to this embodiment, the control unit 15 controls the light intensity of the light source 11 in the light intensity control process as necessary so that the virtual image display brightness setting (brightness of the virtual image VI display based on the virtual image display brightness setting value) is brighter than the real image display brightness setting (brightness of the real image RI display based on the real image display brightness setting value). For example, during the day or evening, when the outside of the vehicle is as bright as or brighter than the inside of the vehicle and the real image RI and virtual image VI have the same brightness in this case, the driver DR will find the real image RI dazzling. Therefore, by controlling the real image RI to be darker (in other words, by controlling the virtual image VI to be brighter), the above-mentioned glare and discomfort can be prevented.

[0056] Furthermore, in the vehicle display device 1 of this embodiment, the control unit 15 controls the light intensity of the light source 11 in the light intensity control process as necessary so that the real image display brightness setting (brightness of the real image RI display based on the real image display brightness setting value) is brighter than the virtual image display brightness setting (brightness of the virtual image VI display based on the virtual image display brightness setting value).For example, at night, the inside of the vehicle (when the interior lights are on) is brighter than the outside of the vehicle, and in this case, if the real image RI and the virtual image VI have the same brightness, the driver DR will find the virtual image VI dazzling.Therefore, by controlling the virtual image VI to be darker (in other words, by making the real image RI brighter), the above-mentioned glare and discomfort can be prevented.

[0057] Furthermore, in the vehicle display device 1 of this embodiment, if necessary, the control unit 15 executes a light intensity control process to control the light intensity of the light source 11 so that the virtual image display brightness setting (brightness of the virtual image VI display based on the virtual image display brightness setting value) is brighter than the real image display brightness setting (brightness of the real image RI display based on the real image display brightness setting value) when the headlights installed in the vehicle C are turned off or when the illuminance of external light detected by the illuminance sensor installed in the vehicle C is equal to or greater than a predetermined value.Therefore, by using the turning off of the headlights or the detected illuminance being equal to or greater than a predetermined value as a trigger, it is possible to accurately detect whether it is daytime or evening, and perform the light intensity control process accurately and reliably.

[0058] Furthermore, in the vehicle display device 1 of this embodiment, if necessary, the control unit 15 executes a light intensity control process to control the light intensity of the light source 11 so that the real image display brightness setting (the brightness of the real image RI display based on the real image display brightness setting value) is brighter than the virtual image display brightness setting (the brightness of the virtual image VI display based on the virtual image display brightness setting value) when the headlights installed in the vehicle C are on or when the illuminance of external light detected by the illuminance sensor installed in the vehicle C is less than a predetermined value.Therefore, by using the headlights being on or the detected illuminance being less than a predetermined value as a trigger, it is possible to accurately detect that it is nighttime and perform the light intensity control process accurately and reliably.

[0059] Furthermore, in the vehicle display device 1 according to this embodiment, when the control unit 15 switches from a relatively dark luminance setting on one side to a relatively bright luminance setting on the other side out of the real image display luminance setting (luminance of the real image RI display based on the real image display luminance setting value) and the virtual image display luminance setting (luminance of the virtual image VI display based on the virtual image display luminance setting value) in the light quantity control process, the control unit 15 controls the light quantity of the light source 11 so that the luminance setting on one side becomes a first transient luminance setting value that is darker than the luminance setting on the other side, and then the luminance increases over time from the first transient luminance setting value to become the luminance setting on the other side. Therefore, when switching from a dark luminance setting to a bright luminance setting, the luminance is not suddenly switched to a bright luminance, but is transiently switched to a luminance that is slightly darker than the bright luminance setting, and then the luminance is gradually increased to transition to the bright luminance setting. This alleviates the discomfort felt by the driver DR due to the luminance switching and reduces the increase in eye strain.

[0060] Furthermore, in the vehicle display device 1 according to this embodiment, when the control unit 15 switches from a relatively brighter luminance setting on the other side to a relatively darker luminance setting on the one side out of the real image display luminance setting (luminance of the real image RI display based on the real image display luminance setting value) and the virtual image display luminance setting (luminance of the virtual image VI display based on the virtual image display luminance setting value) in the light quantity control process, the control unit 15 controls the light quantity of the light source 11 so that the luminance setting on the other side becomes a second transient luminance setting value that is darker than the luminance setting on the one side, and then the luminance increases over time from the second transient luminance setting to the luminance setting on the one side. Therefore, when switching from a bright luminance setting to a dark luminance setting, the luminance is not switched to a dark luminance suddenly, but is switched to a luminance that is slightly darker than the dark luminance setting, and then the luminance is gradually increased to transition to the dark luminance setting. This alleviates the discomfort felt by the driver DR due to the luminance switching and reduces the increase in eye strain.

[0061] Furthermore, in the vehicle display device 1 of this embodiment, the reflecting unit 13 includes, as necessary, a first mirror 131 that reflects the display light L1 and transmits the display light L2, and a second mirror 132 that reflects the display light L2. When the display element 121 emits the display light L1, the first mirror 131 and the second mirror 132 are in a first state in which the positional relationship between the optical focus F of the imaging optical system including the windshield WS and the reflecting unit 13 and the display unit 12 is such that the display unit 12 is closer to the opening 17 than the optical focus F, allowing the virtual image VI to be viewed. When the display element 121 emits the display light L2, the first mirror 131 and the second mirror 132 are in a second state in which the display unit 12 is closer to the light source 11 than the optical focus F, allowing the real image RI to be viewed. This allows smooth switching between real image RI display and virtual image VI display.

[0062] (Second embodiment of the present invention) The vehicle display device 1 according to this embodiment will be described with reference to Fig. 12. The vehicle display device 1 according to this embodiment has a configuration in which the HUD device 2 has two PGUs (Picture Generation Units). Note that in this embodiment, descriptions that overlap with those in the first embodiment will be omitted.

[0063] 12 is a diagram showing the configuration of a vehicle display device 1 according to this embodiment. In FIG. 12, the HUD device 2 of the vehicle display device 1 includes a first PGU 10a having a first light source 11a that emits light in the visible wavelength range, for example, and a first display unit 12a that transmits the light emitted by the first light source 11a and displays a real image RI of a display image formed in front of the driver DR, and a second PGU 10b having at least a second light source 11b that emits light in the visible wavelength range, for example, and a second display unit 12b that transmits the light emitted by the second light source 11b and displays a virtual image VI of a display image formed in front of the driver DR. The display device includes a GU10b, a reflecting unit 13 that reflects a first display light L11 representing the display image displayed on the first display unit 12a and a second display light L22 representing the display image displayed on the second display unit 12b toward a windshield WS (translucent member), and a control unit 15 that controls the display content on the first display unit 12a and the second display unit 12b, controls switching between the first PGU10a and the second PGU10b, and controls brightness by adjusting the amount of light emitted by the first light source 11a and the second light source 11b, and these are housed in a housing 16.

[0064] As for the control unit 15, as shown in FIG. 12, the first PGU 10a and the second PGU 10b may be controlled by a single control unit 15, or the first PGU 10a and the second PGU 10b may each have their own control unit, and the control unit 15 may control these individual control units in cooperation with each other.

[0065] 12, the first light source 11a is, for example, a light-emitting diode (LED) mounted on a wiring board that emits light in the visible wavelength range and emits white light. The first display unit 12a is provided closer to the opening 17 along the optical path than the first light source 11a, and has a TFT-type first display element (not shown) that forms first display light L11 that displays an arbitrary image in accordance with a control signal sent from the control unit 15.

[0066] 12, the second 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 second display unit 12b is provided closer to the opening 17 along the optical path than the second light source 11b, and has a TFT-type second display element (not shown) that forms second display light L22 that displays an arbitrary image in accordance with a control signal sent from the control unit 15.

[0067] In addition to the above, in the first PGU 10a and the second PGU 10b, optical components such as a condenser lens, a lenticular lens, a diffusion plate, and a polarizing plate may be arranged at any position downstream of the first light source 11a and the second light source 11b, respectively.

[0068] 12, the reflecting unit 13 includes a first correcting mirror 1310 that reflects the first display light L11 emitted from the first display unit 12a toward the second correcting mirror 1320, a second correcting mirror 1320 that reflects the first display light L11 emitted from the first correcting mirror 1310 toward the concave mirror 1330, and a concave mirror 1330 that reflects the first display light L11 reflected and folded by the first correcting mirror 1310 and the second correcting mirror 1320 and the second display light L22 that has passed through the second correcting mirror 1320 toward the opening 17.

[0069] The first correcting mirror 1310 and the second correcting mirror 1320 have mirrored surfaces and are formed into complex free-form shapes to correct distortion of the image viewed by the driver DR. The second correcting mirror 1320 is, for example, a half mirror, and transmits the second display light L22 representing the virtual image VI displayed on the second display unit 12b. The second display light L22 transmitted through the second correcting mirror 1320 is directly incident on the concave mirror 1330. The concave mirror 1330 is rotatably installed and rotates to match the position of the driver DR's eyes, freely changing the emission direction of the first display light L11 and the second display light L22 and adjusting the position of the image. In particular, it may be desirable to have different angles of the display surface when the first display light L11 displays a real image RI and when the second display light L22 displays a virtual image VI (for example, displaying the virtual image VI as if it is inclined relative to the road surface, and displaying the real image RI as if it is standing perpendicular to the road surface), and by performing such adjustments using rotational drive, it is possible to display the display images at angles appropriate for the real image RI and virtual image VI, respectively.

[0070] The first correcting mirror 1310 is disposed along the optical path of the first display light L11 closer to the opening 17 than the first PGU 10a, and is disposed closer to the first PGU 10a than the first optical focal point F1 of the imaging optical system including the windshield WS, the second correcting mirror 1320, and the concave mirror 1330. The second display unit 12b of the second PGU 10b is disposed along the optical path of the second display light L22 closer to the opening 17 than the position of the second optical focal point F2 of the imaging optical system including the windshield WS and the concave mirror 1330.

[0071] With this configuration, when the first light source 11a is turned on, the first display light L11 emitted from the first PGU 10a is reflected by the first correcting mirror 1310, the second correcting mirror 1320, the concave mirror 1330, and the windshield WS, allowing the driver DR to view a real image RI on the inside of the vehicle through the windshield WS. Also, when the second light source 11b is turned on, the second display light L22 emitted from the second PGU 10b passes through the second correcting mirror 1320 and is reflected by the concave mirror 1330 and the windshield WS, allowing the driver DR to view a virtual image VI on the outside of the vehicle through the windshield WS.

[0072] The control unit 15 controls the first PGU 10a and the second PGU 10b in cooperation with each other, turns on / off the first light source 11a and the second light source 11b, controls the display content of the first display unit 12a, controls the display content of the second display unit 12b, and adjusts the amount of light emitted by the first light source 11a and the second light source 11b to control the brightness of the first display light L11 emitted by the first display unit 12a and the second display light L22 emitted by the second display unit 12b.

[0073] In this embodiment, the control unit 15 controls the setting and change of the luminance of the real image RI and the setting and change of the luminance of the virtual image VI so as to behave in the same manner as in the first embodiment. That is, in accordance with the flowchart of Fig. 11, in each of the scenes shown in Fig. 5 to Fig. 7, the luminance value is controlled as shown in Fig. 8, and the luminance of the real image RI and the luminance of the virtual image VI are adjusted in the same change manner as in Fig. 9 and Fig. 10.

[0074] In the first embodiment, the real image luminance adjustment unit 54a controls the luminance of the display light L2 for the real image RI, which is the second polarization, by adjusting the light intensity of the light source 11, and the virtual image luminance adjustment unit 54b controls the luminance of the display light L1 for the virtual image VI, which is the first polarization, by adjusting the light intensity of the light source 11. However, in the present embodiment, the real image luminance adjustment unit 54a controls the luminance of the first display light L11 by adjusting the light intensity of the first light source 11a, which is the light source for the real image RI, and the virtual image luminance adjustment unit 54b controls the luminance of the second display light L22 by adjusting the light intensity of the second light source 11b, which is the light source for the virtual image VI.

[0075] In addition, in the configuration of the vehicle display device 1 shown in Fig. 12, by turning on both the first light source 11a and the second light source 11b, it is possible to simultaneously display the real image RI and the virtual image VI. In this simultaneous display case, the control unit 15 controls the luminance of the real image RI and the luminance of the virtual image VI in accordance with the display luminance setting information 52 (real image display luminance setting value and virtual image display luminance setting value) for each scene shown in Figs. 5 to 7. That is, in the daytime of Fig. 5 and the evening of Fig. 6, the luminance of the virtual image VI displayed outside the vehicle is controlled to be relatively higher than the luminance of the real image RI displayed inside the vehicle, and in the nighttime of Fig. 7, the luminance of the real image RI displayed inside the vehicle is controlled to be relatively higher than the luminance of the virtual image VI displayed outside the vehicle.

[0076] Furthermore, when the real image RI and the virtual image VI are simultaneously displayed and the ambient light outside or inside the vehicle transitions from a bright state to a dark state or from a dark state to a bright state (for example, when entering or exiting a tunnel during the day), the control unit 15 controls the luminance of each displayed image according to the transition of each scene. Specifically, for example, when transitioning from a bright daytime state (e.g., corresponding to the cases of FIGS. 5 and 6) to a dark tunnel state (e.g., corresponding to the case of FIG. 7), the display state in which the luminance of the real image RI is low and the luminance of the virtual image VI is high is controlled to a display state in which the luminance of the real image RI is high and the luminance of the virtual image VI is low. Also, when transitioning from a dark tunnel state (e.g., corresponding to the state of FIG. 7) to a bright daytime state after exiting the tunnel (e.g., corresponding to FIGS. 5 and 6), the display state in which the luminance of the real image RI is high and the luminance of the virtual image VI is low is controlled to a display state in which the luminance of the real image RI is high and the luminance of the virtual image VI is low.

[0077] As described above, in the vehicle display device 1 according to this embodiment, even in the configuration including the first PGU 10a and the second PGU 10b, it is possible to avoid the visual discomfort and glare felt by the driver DR, as in the case of the first embodiment. Furthermore, it is possible to simultaneously display the virtual image VI and the real image RI, and even in this case, it is possible to avoid the visual discomfort and glare felt by the driver DR by adjusting the brightness of each image. [Explanation of symbols]

[0078] C vehicle DR Driver F optical focus F1 1st optical focus F2 2nd optical focus L(L1,L2) Display light L11 1st display light L22 2nd display light VI Virtual Image RI real image R1,R2 radius of curvature WS Window Shield 1. Vehicle display device 2 HUD device 3. Settings 11 Light source 11a 1st light source 11b Second light source 12 Display section 12a 1st display section 12b 2nd display section 13 Reflector 15 Control Unit 16 Case 17 Opening 18 Coverslips 20 Switch 21 Display control unit 22 Display drive unit 30 Various Devices 51 Operation section 52 Display brightness setting information 53 External Information 54 Light quantity control unit 54a Real image brightness adjustment section 54b Virtual image brightness adjustment unit 55 Switching control section 56 Display control unit 121 Display element 122 Switching element 131 1st Mirror 132 Second Mirror 133 Third Mirror 1310 First correcting mirror 1320 Second corrector mirror 1330 concave mirror

Claims

1. A vehicle display device is provided in a vehicle including a seat on which a passenger sits and a light-transmitting member, and emits display light from an emission port toward the light-transmitting member, thereby allowing a virtual image and a real image of a display image represented by the display light to be visually recognized, a display unit including a display element, which transmits light emitted from the light source and displays the display image; a reflecting section that reflects light representing the display image displayed on the display section toward the light-transmitting member; A control unit; and The control unit A light amount control process is executed to control the light amount of the light source so that a first display luminance setting when the real image is viewed and a second display luminance setting when the virtual image is viewed have a predetermined luminance difference from each other. A vehicle display device comprising:

2. The control unit, in the light amount control process, The light amount of the light source is controlled so that the second display luminance setting is brighter than the first display luminance setting.

2. The vehicle display device according to claim 1.

3. The control unit, in the light amount control process, The light amount of the light source is controlled so that the first display luminance setting is brighter than the second display luminance setting.

2. The vehicle display device according to claim 1.

4. The control unit When a headlight provided in the vehicle is turned off or when the illuminance of external light detected by an illuminance sensor provided in the vehicle is less than a predetermined value, the light amount control process is executed to control the light amount of the light source so that the second display luminance setting is brighter than the first display luminance setting.

3. The vehicle display device according to claim 2.

5. The control unit When a headlight provided in the vehicle is turned on or when the illuminance of external light detected by an illuminance sensor provided in the vehicle is equal to or greater than a predetermined value, the light amount control process is executed to control the light amount of the light source so that the first display luminance setting is brighter than the second display luminance setting.

4. The vehicle display device according to claim 3.

6. The control unit When switching from one relatively darker luminance setting to the other relatively brighter luminance setting of the first display luminance setting and the second display luminance setting in the light amount control process, The light amount of the light source is controlled so that the brightness setting of one side is changed to a first transient brightness setting that is darker than the brightness setting of the other side, and then the brightness increases over time from the first transient brightness setting to the brightness setting of the other side.

6. The vehicle display device according to claim 2, wherein the display device is a display unit for displaying a vehicle image.

7. The control unit When switching from the relatively brighter luminance setting to the relatively darker luminance setting of the first display luminance setting and the second display luminance setting in the light amount control process, The light amount of the light source is controlled so that the luminance setting of the other side is changed to a second transient luminance setting that is darker than the luminance setting of the one side, and then the luminance increases over time from the second transient luminance setting to the luminance setting of the one side.

6. The vehicle display device according to claim 2, wherein the display device is a display unit for displaying a vehicle image.

8. The reflecting portion is a first mirror that reflects the first light beam and transmits the second light beam; a second mirror that reflects the second light beam; Including, The first mirror and the second mirror are When the display element emits the first light ray, a positional relationship between an optical focus of an imaging optical system including the light-transmitting member and the reflecting portion and the display portion becomes a first state in which the display portion is closer to the exit port than the optical focus, thereby making the virtual image visible; When the display element emits the second light beam, the display unit is in a second state in which it is closer to the light source than the optical focus, and the real image is visible.

2. The vehicle display device according to claim 1, wherein the display device is arranged as follows:

Images