JP2016053690A - In-vehicle projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-vehicle projection display device capable of providing a display image with a sense of perspective and depth, as necessary, that matches outside scenery seen at a position overlapping the display image while suppressing an increase in cost of the device.SOLUTION: An in-vehicle projection display device includes a tilt adjustment mechanism 55 for adjusting a direction of an image plane 22 of a virtual image 21 relative to a direction of an optical axis 18. When presenting a virtual image 21 with a sense of depth, the tilt adjustment mechanism 55 is adjusted such that the image plane 22 is placed at an angle with a plane perpendicular to a direction of a line of sight 18 connecting an eye point EP and the virtual image. In order to tilt the image plane 22, the two-dimensional display panel 11 is positioned aslant, and exit light 13 of the two-dimensional display panel 11 is directed in a direction at an angle with a direction perpendicular to a surface of the two-dimensional display panel 11. Switching between the tilted state and untilted state of the image plane 22 is automatic.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle projection display device that performs display using light reflection of a windshield (window glass) or the like in front of a driver in a vehicle.

  For example, in a general vehicle head-up display (HUD) device, an image of light including various information to be displayed is projected from a HUD unit onto a front windshield or a reflector called a combiner, and the front windshield The light path is formed so that the light reflected by the light heads in the direction of the driver's viewpoint. Accordingly, the driver can visually recognize the HUD displayed on the front windshield or the like as a virtual image while simultaneously viewing the scenery in front of the vehicle through the front windshield. That is, the driver can visually recognize various information by displaying the HUD without moving the line of sight while maintaining the normal driving state.

Prior arts related to the present invention are disclosed in, for example, Patent Documents 1 to 4.
In Patent Document 1, in order to perform pseudo-stereoscopic display on a display screen of a gaming machine, a shadow is displayed in a background area adjacent to a display area such as a character pattern.

  In Patent Document 2, in order to enable pseudo-stereoscopic display, a display unit, a mirror that reflects an image displayed on the display unit toward an observation position, and an angle variable unit that changes the angle of the mirror are provided. I have.

  Patent Document 3 shows a vehicle display device (HUD device) that can be easily attached to an appropriate arrangement position in the depth direction.

  Patent Document 4 shows that in a HUD device, a right-eye virtual image and a left-eye virtual image are respectively displayed using independent right-eye display and left-eye display to display a stereoscopic image.

JP 11-47374 A JP 2009-145829 A JP 2013-241035 A JP, 2014-10418, A

  In a vehicle HUD, a display image projected as a virtual image and an actual scenery outside the vehicle are generally displayed in an overlapping state. In this case, since the display image displayed by the HUD is a planar image, the stereoscopic landscape and the planar image overlap at the same position and are visually recognized by the driver in a somewhat unnatural state. Specifically, since the scenery with perspective and the display image without perspective overlap, it becomes difficult for the driver to adjust the focus of the eyes when viewing either the scenery or the display image. In addition, the driver may feel uncomfortable due to the difference in distance between the scenery and the display image. In addition, when the perspective in the actual landscape does not match the status of the display content, it is difficult for the driver to intuitively grasp the current status from the display content. Furthermore, in the case of flat display, there is a high possibility that a cheap impression will be given to the user, leading to a reduction in the value of the device.

  If the HUD display image can be displayed with perspective, it is considered that the above problems can be solved or alleviated. However, in the case of adopting the technique as disclosed in Patent Document 4, since a plurality of displays are required, it is inevitable that the cost of the apparatus increases significantly. In the technique disclosed in Patent Document 3, the display position can be adjusted in the front-rear direction, but display with a sense of perspective cannot be performed. Further, in the technique of Patent Document 2, the position for displaying an image greatly moves with the change in the angle of the mirror, so that the position of the display image cannot be fixed. Further, the technique of Patent Document 1 is a pseudo three-dimensional display using the density of the background, and since the distance from the eye position to the image to be viewed is constant, the perspective cannot actually be obtained.

  Furthermore, in order to accurately display a pseudo stereoscopic display pattern, a storage device is required to hold data of various display patterns determined in advance, or a stereoscopic image is drawn on two-dimensional coordinates. Therefore, a high-performance graphic display processor is required, so that the cost of the apparatus is inevitably increased.

  The present invention has been made in view of the above-described circumstances, and its purpose is to suppress the increase in the cost of the apparatus, while providing a sense of perspective that matches the scenery outside the vehicle reflected in a position overlapping with the display image or in an adjacent position. An object of the present invention is to provide a vehicular projection display device capable of forming a depth as required.

In order to achieve the above-described object, a vehicle projection display device according to the present invention is characterized by the following (1) to (5).
(1) Light including an arbitrary display image formed in a planar shape in a predetermined display area is emitted from the projection unit and guided to the windshield of the vehicle or the vicinity thereof, and reflected by the surface of the windshield or the vicinity thereof A projection display device for a vehicle that projects the display image of the light so as to be visually recognized as a virtual image at a predetermined eye point,
A tilt adjustment mechanism that adjusts the orientation of the imaging plane of the virtual image with respect to the orientation of the optical axis;
The imaging plane whose direction is adjusted by the tilt adjustment mechanism is arranged in a state inclined with respect to a plane orthogonal to the direction of the line of sight connecting the eye point and the virtual image.
A projection display apparatus for a vehicle characterized by the above.
(2) A vehicle projection display device having the configuration of (1) above,
The tilt adjustment mechanism is connected to a support member that supports a display panel that displays the display image,
In the state in which the imaging plane is inclined, the light emitted from the projection unit is generated using the light directed toward the direction of the inclined axis inclined with respect to the direction perpendicular to the surface of the display panel.
A projection display apparatus for a vehicle characterized by the above.
(3) A vehicle projection display device having the configuration of (1) above,
When the information displayed as the virtual image satisfies a predetermined display condition, the image forming apparatus further includes a tilt control unit that drives the tilt adjustment mechanism to position the orientation of the image plane of the virtual image in a predetermined tilt state. ,
A projection display apparatus for a vehicle characterized by the above.
(4) The vehicle projection display device having the configuration of (3) above,
When the virtual image is arranged at a position lower than the horizontal direction viewed from the eye point, the tilt control unit is configured to reach the upper end of the virtual image compared to the distance from the eye point to the lower end of the virtual image. Adjusting the inclination of the imaging plane of the virtual image in the direction in which the distance increases.
A projection display apparatus for a vehicle characterized by the above.
(5) A vehicle projection display device having the configuration of (2) above,
The display panel is a transmissive display device,
A lighting backlight disposed on the back side of the display panel;
A projection display apparatus for a vehicle characterized by the above.

According to the vehicle projection display device having the configuration of (1) above, by adjusting the tilt adjustment mechanism, the imaging plane is perpendicular to the direction of the line of sight connecting the eye point and the virtual image. And can be arranged so as to be inclined. Thereby, about the distance between the eye point equivalent to the position of a driver | operator's viewpoint, and the said virtual image, a difference arises by the lower end of the said virtual image, and an upper end. That is, even if a special stereoscopic image is not displayed, a perspective and a depth according to the difference in the vertical position are generated for each region on the virtual image. By adjusting the angle by the tilt adjusting mechanism, it is possible to match the perspective on the virtual image with the perspective in the actual landscape.
According to the projection display apparatus for a vehicle having the configuration (2), the virtual image is formed using light in a direction inclined with respect to a direction perpendicular to the surface of the display panel. However, it can arrange | position so that it may incline with respect to the surface orthogonal to the direction of a gaze. That is, by arranging the display panel in an inclined state, the image plane of the virtual image can also be inclined.
According to the vehicle projection display device having the configuration (3), the perspective and the depth can be automatically adjusted according to the contents of the image displayed as the virtual image. In addition, a display without a sense of incongruity becomes possible.
According to the vehicle projection display device having the configuration of (4) above, the difference in perspective in the vertical direction on the tilted virtual image is the difference in perspective when the road surface or the like of the road is viewed from the eye point. And close to the state. As a result, the uncomfortable feeling felt by the driver can be eliminated, and the focus adjustment of the eyes due to the difference in position is facilitated.
According to the vehicle projection display apparatus having the configuration (5), the display panel is illuminated from the back side using the backlight, so that a sufficiently large amount of light can be obtained in the direction of the tilt axis. It becomes possible to emit.

  According to the projection display apparatus for a vehicle of the present invention, it is possible to form a sense of perspective and depth according to the scenery outside the vehicle reflected in a position overlapping with or adjacent to the display image while suppressing an increase in the cost of the apparatus. is there. That is, even if a stereoscopic image is not formed, a desired perspective and depth can be obtained by tilting the surface of the displayed virtual image. Since it is not necessary to draw a stereoscopic image, a low-cost device can be realized.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

FIG. 1A and FIG. 1B are optical path diagrams showing optical paths of respective parts in a state where a vehicle equipped with a vehicle projection display device is viewed from the side, and FIG. FIG. 1B shows a tilt adjustment state of the virtual image forming surface. FIG. 2 is a front view showing a specific example of the scenery in front of the vehicle and the displayed virtual image that can be visually recognized by the driver of the vehicle. FIG. 3 is a side view showing a configuration example (1) of a two-dimensional display panel usable in the vehicle projection display device of FIG. FIG. 4 is a side view showing a configuration example (2) of the two-dimensional display panel usable in the vehicle projection display device of FIG. FIG. 5 is a block diagram illustrating a configuration example of a system including a vehicle projection display device. FIG. 6 is a flowchart showing main operations of the vehicle projection display apparatus. FIG. 7A is a front view showing a specific example of an image displayed on the screen of the two-dimensional display panel, and FIG. 7B is a view of a virtual image formed on an inclined virtual image imaging plane viewed from the viewpoint side. It is a front view showing a visible state.

  Specific embodiments relating to the vehicle projection display apparatus of the present invention will be described below with reference to the drawings.

<Outline of vehicle projection display device>
FIG. 1A and FIG. 1B show an outline of the layout of each part and the optical path in a state where a vehicle equipped with the vehicle projection display device of the embodiment of the present invention is viewed from the side. FIG. 1A shows a state in which the virtual image forming surface 22 is oriented in the vertical direction, and FIG. 1B shows a tilt adjustment state of the virtual image forming surface 22. Further, the vehicle projection display device of the present embodiment constitutes a head-up display (HUD).

  The HUD unit 10 shown in FIGS. 1A and 1B is incorporated inside a dashboard arranged in front of the driver's seat of the vehicle. Inside the HUD unit 10, a two-dimensional display panel 11 and a reflecting mirror 15 are provided. The two-dimensional display panel 11 has a screen capable of displaying various patterns of visible information such as numerical values, characters, and figures as necessary. As a specific example, a numerical value indicating the display value of the current speedometer of the vehicle or characters such as “km / h” can be displayed on the screen. Further, the two-dimensional display panel 11 can emit light including visible information displayed on the screen as emitted light 13.

  The emitted light 13 from the two-dimensional display panel 11 is emitted from an opening (not shown) of the HUD unit 10 toward the reflecting mirror 15 and further reflected upward from the surface of the reflecting mirror 15 and directed upward. . The reflecting mirror 15 forms a magnifying optical system. The outgoing light 16 emitted from the HUD unit 10 is reflected by a region 17a where a windshield (window glass) 17 of the vehicle is present, and travels toward the viewpoint EP.

  Therefore, when a vehicle driver or the like views the direction of the line of sight 18 from the position of the viewpoint EP, the virtual image 21 can be viewed at a position in front of the area 17a of the windshield 17. That is, the same image as the content of the visible image displayed on the screen of the two-dimensional display panel 11 is formed as a virtual image 21 at the position of the virtual image imaging plane 22.

  Therefore, when the driver of the vehicle sees the direction of the line of sight 18 from the position of the viewpoint EP, the driver of the HUD unit 10 is in a state where the position overlaps with the scenery outside the vehicle (the road surface of the road, the hood of the own vehicle, etc.). The virtual image 21 which is a display image can be visually recognized.

  One of the characteristic features in the configuration shown in FIGS. 1A and 1B is that the orientation of the virtual image imaging plane 22 is variable, and the orientation of the virtual image imaging plane 22 is centered on the rotation axis 22c. To change. Therefore, the virtual image imaging plane 22 can be arranged so as to be inclined with respect to the direction orthogonal to the line of sight 18.

  Further, in order to make the orientation of the virtual image forming plane 22 variable, the two-dimensional display panel 11 shown in FIGS. 1A and 1B can freely rotate about a rotation shaft 11 c disposed near the center. It is supported by. In addition, an inclination adjusting mechanism 55 is connected to the two-dimensional display panel 11. The tilt adjusting mechanism 55 moves the tilt adjusting mechanism 55 by a driving force of an electric motor, which will be described later, and positions the direction of the surface of the two-dimensional display panel 11 in various directions as shown in FIG. can do. The inclination adjusting mechanism 55 may be a mechanism that moves in the rotational direction or a link mechanism that moves linearly. By disposing the two-dimensional display panel 11 in an inclined state, the virtual image imaging plane 22 can be inclined. When the 2D display panel 11 is tilted, the optical axis of the emitted light 13 is also tilted with respect to the direction perpendicular to the surface of the 2D display panel 11.

<Specific examples of driver visibility>
A specific example of the scenery in front of the vehicle that can be visually recognized by the driver of the vehicle and the displayed virtual image is shown in FIG. That is, the driver who is seated in the driver's seat of the vehicle can visually recognize the landscape 30 as shown in FIG. 2 through the transparent windshield 17, for example. In the case of a vehicle equipped with the HUD unit 10 of FIG. 1, for example, a virtual image 21 displayed at the position of the HUD display area 20 shown in FIG.

<Scenery visibility>
As shown in FIG. 2, the scenery 30 that the driver visually recognizes includes a road surface 30a, a lane marking 30b on the road surface, etc., and these scenery 30 are directed toward an infinite point 31 ahead on the road. It is visually recognized as a situation that converges. For example, in the area A1 in the range from the lower end of the area visually recognized by the driver to the position Yc in the vertical direction corresponding to the infinity point 31, the width of the road surface 30a and the lane marking 30b decreases toward the top. In other words, it can be seen that the distance to the object increases as it goes upward. Also, it can be seen that in the region A2 in the range from the vertical position Yc to the upper end, the distance to the object becomes farther downward. Note that the infinity point 31 is located far away when the driver views the front in the horizontal direction from the viewpoint EP in a normal state.

<Visual status of virtual images>
In a situation where the virtual image forming plane 22 shown in FIG. 1 is inclined with respect to a plane perpendicular to the direction of the line of sight 18, as shown in FIG. 2, the HUD display area 20 on which the virtual image 21 is displayed is It has a trapezoidal shape. In the example of FIG. 2, the width in the X direction of the region upper end 20a is smaller than the width of the region lower end 20b. Therefore, the shape of the HUD display area 20 gives the driver a sense of distance similar to the sense of distance of the landscape 30 that converges toward the infinity point 31.

  Actually, the HUD display area 20 shown in FIG. 2 corresponds to the virtual image imaging plane 22 shown in FIG. For example, when the virtual image forming surface 22 is inclined as in the direction of the virtual image forming surface 22 (B) shown in FIG. 1B, the distance from the viewpoint EP to the region upper end 20a of the HUD display region 20 Is larger than the distance to the region lower end 20b. Therefore, when viewed from the viewpoint EP, the region upper end 20a is located farther than the region lower end 20b, and the virtual image 21 formed on the inclined HUD display region 20 can actually give a sense of perspective.

  In addition, the perspective on the virtual image 21 formed by the inclination of the virtual image forming surface 22 and the perspective of the scenery 30 in the vicinity thereof appear in the same direction. That is, both the virtual image 21 and the landscape 30 are in a state of being farther away as they approach the position of the infinite point 31, making it difficult for visual discomfort to occur, and facilitating adjustment of the driver's eyes. .

<Configuration example (2) of two-dimensional display panel 11>
FIG. 3 shows a configuration example (1) of a two-dimensional display panel that can be used in the vehicle projection display apparatus of FIG.

  In the configuration shown in FIG. 3, a transmissive liquid crystal display panel 11 </ b> A is employed as the above-described two-dimensional display panel 11. A backlight 12 is disposed on the back side of the transmissive liquid crystal display panel 11A.

  In the example shown in FIG. 3, the surface of the flat transmissive liquid crystal display panel 11 </ b> A is positioned by the tilt adjusting mechanism 55 in a state tilted by a predetermined angle θ with respect to the vertical direction (Y axis). . The backlight 12 irradiates illumination light 12a in the Z-axis direction. For example, white light is used as the illumination light 12a. When the illumination light 12a passes through the transmissive liquid crystal display panel 11A, the shading and color are modulated in accordance with the contents of the display image 11a, and the illumination light 12a is emitted as the emitted light 13 in the Z direction.

  When the transmissive liquid crystal display panel 11A is inclined as shown in FIG. 3, the points P1, P2, and P3 at different positions on the display image 11a exist at positions shifted from each other in the Z-axis direction. . That is, there is a difference in position in the optical axis direction (Z direction) among the coordinates (y1, z1) of the point P1, the coordinates (y2, z2) of the point P2, and the coordinates (y3, z3) of the point P3.

  Therefore, for example, the virtual image imaging plane 22 is inclined in the same manner as the transmissive liquid crystal display panel 11A due to the difference in the position in the Z direction of each of the points P1, P2, and P3 which are light sources when displaying the virtual image 21 of FIG. become. That is, the transmissive liquid crystal display panel 11A is disposed in an inclined state, and the emitted light 13 is emitted in a direction (Z) inclined with respect to a direction perpendicular to the surface of the transmissive liquid crystal display panel 11A, thereby forming a virtual image. The virtual image 21 can be displayed so that the surface 22 is inclined. Further, the depth of the virtual image 21 can be changed by adjusting the tilt angle (θ) of the transmissive liquid crystal display panel 11A.

<Configuration example (2) of two-dimensional display panel 11>
FIG. 4 shows a configuration example (2) of the two-dimensional display panel and its peripheral part that can be used in the vehicle projection display device of FIG.

  In the configuration shown in FIG. 4, a self-luminous display panel 11 </ b> B is employed as the above-described two-dimensional display panel 11. Specifically, an organic EL display panel can be used as the self-luminous display panel 11B. Similar to the configuration shown in FIG. 3, the plane of the planar self-luminous display panel 11 </ b> B is positioned in a state inclined by a predetermined angle θ with respect to the vertical direction (Y-axis).

  In the configuration of FIG. 4, the optical filter 14 is disposed on the front side of the self-luminous display panel 11B. The optical filter 14 provides a function necessary for obtaining the emitted light 13 traveling in the Z-axis direction from the display image 11a. As a specific example, an optical member having direction selectivity is used for the optical filter 14 so as to transmit light traveling in the Z direction and to shield light other than the Z direction. Thereby, it is possible to prevent extra light other than the emitted light 13 from going to the reflecting mirror 15.

  Further, when the display viewing angle in the self-luminous display panel 11B is relatively narrow, an optical material that refracts light is used for the optical filter 14, and the light emission direction from the self-luminous display panel 11B is maximized. The direction (generally perpendicular to the surface) is inclined to refract the light so that it faces the Z direction. Thereby, the light quantity of the emitted light 13 can be increased, and the visibility of the virtual image 21 is improved.

  Note that when positioning the surface of the self-luminous display panel 11B so as to face the direction parallel to the Y-axis, the optical filter 14 is disposed on the self-luminous display panel in order to avoid attenuation of the emitted light 13 due to the influence of the optical filter 14. It is necessary to shift from a position facing the surface of 11B or to adjust the direction of the optical filter 14.

<System configuration example>
FIG. 5 shows a configuration example of a system including the vehicle projection display device shown in FIGS. 1 (A) and 1 (B). The system shown in FIG. 5 includes a meter unit 100 and a car navigation device 200 mounted on the vehicle in addition to the HUD unit 10.

  The meter unit 100 incorporates various instruments represented by a speedometer and various displays. For example, when the HUD unit 10 in FIG. 5 displays the vehicle speed as the virtual image 21, the vehicle speed information output from the meter unit 100 is input to the HUD unit 10.

  The car navigation device 200 grasps the current position of the host vehicle, displays a map including the current position on a predetermined screen, and guides the driver to travel along a predetermined travel route. Can do. It also has a turn-by-turn guidance function. For example, when the current position of the host vehicle approaches an intersection on the moving route, the traveling direction can be notified by voice or arrow display. When a left turn or a right turn is guided by the turn-by-turn guidance function, the car navigation device 200 in FIG. 5 outputs information on the left turn display or the right turn display to the HUD unit 10.

  The HUD unit 10 shown in FIG. 5 includes a display control unit 51, a nonvolatile memory 52, a motor driver 53, an electric motor 54, and a tilt adjustment mechanism 55.

  The display control unit 51 is configured by a microcomputer, and can implement various control functions required for the HUD unit 10 by executing a program incorporated in advance. Further, the display control unit 51 can perform data communication between the meter unit 100 and the car navigation device 200.

  The nonvolatile memory 52 holds in advance fixed data of various display patterns displayed on the screen of the two-dimensional display panel 11 and various constant data necessary for control of the display control unit 51. For example, when the HUD unit 10 performs a right turn guidance display according to the output of the car navigation device 200, the display control unit 51 reads the right turn guidance display pattern from the nonvolatile memory 52 and displays it on the screen of the two-dimensional display panel 11. Is displayed as shown in FIG.

  The display control unit 51 drives the electric motor 54 via the motor driver 53 when it is necessary to adjust the inclination of the surface of the two-dimensional display panel 11. Thereby, the tilt adjustment mechanism 55 connected to the electric motor 54 moves, and the tilt angle of the two-dimensional display panel 11 changes.

<Description of characteristic control operations>
FIG. 6 shows a control procedure of main operations that are characteristic of the vehicular projection display apparatus shown in FIGS. That is, characteristic control can be realized by the display control unit 51 shown in FIG. 5, for example, periodically executing the processing of FIG. The contents of the process in FIG. 6 will be described below.

  In step S11, the display control unit 51 identifies the presence / absence of an HUD display update instruction. For example, when display information having a display priority higher than the information currently displayed on the screen of the two-dimensional display panel 11 is input from the meter unit 100 or the car navigation device 200, it is considered that there is an update instruction and is next. Proceed to S12.

  In step S12, the display control unit 51 identifies whether the attribute of the pattern (image) to be displayed is a stereoscopic image.

  For patterns that are more desirable to display as a plane image, for example, numerical data representing the vehicle speed, attributes of the plane image are given, and patterns that are preferably displayed as a three-dimensional image, such as an arrow pattern for guiding a right turn or left turn Gives the attributes of a stereoscopic image. Data of such attributes is determined in advance and registered in the nonvolatile memory 52. Therefore, the display control unit 51 can identify the attribute by referring to the contents of the nonvolatile memory 52. When displaying pattern data having a stereoscopic image attribute, the process proceeds to S13, and when displaying pattern data having a planar image attribute, the process proceeds to S14.

  In step S13, the display control unit 51 drives the tilt adjustment mechanism 55 to position the two-dimensional display panel 11 in a tilted state. As a result, the virtual image forming surface 22 is inclined by a predetermined angle with respect to the surface orthogonal to the direction of the line of sight 18 as in the direction of the virtual image forming surface 22 (B) shown in FIG. Positioned.

  In step S <b> 14, the display control unit 51 drives the tilt adjustment mechanism 55 to position the two-dimensional display panel 11 in a direction in which the surface of the two-dimensional display panel 11 is perpendicular to the optical axis of the emitted light 13. Thereby, the orientation of the virtual image imaging plane 22 is positioned in a direction orthogonal to the orientation of the line of sight 18 like the orientation of the virtual image imaging plane 22 (A) shown in FIG.

<Description of specific display examples>
A specific example of an image displayed on the screen of the two-dimensional display panel 11 by the HUD unit 10 is shown in FIG. Further, FIG. 7B shows a visual recognition state when the virtual image 21 formed on the virtual image forming surface 22 inclined by a predetermined angle is viewed from the viewpoint EP side.

  For example, when a right turn guidance display command is input from the car navigation device 200 to the display control unit 51 of the HUD unit 10, the display control unit 51 reads the pattern data of the right turn guidance display from the non-volatile memory 52. It is displayed on the screen of the dimension display panel 11. Thereby, a right turn arrow pattern as shown in FIG. 7A is displayed on the screen of the two-dimensional display panel 11.

  In addition, since the right-turn arrow pattern is easier to see in the perspective display, the attributes of the stereoscopic image are given in advance. Therefore, when displaying the right turn arrow pattern, the display control unit 51 executes S13 in FIG. 6 and positions the two-dimensional display panel 11 in an inclined state. Thereby, the virtual image forming surface 22 is also inclined. As a result, the virtual image 21 visually recognized on the viewpoint EP side becomes a display form having a sense of perspective and depth as shown in FIG. 7B due to the influence of the inclination of the virtual image forming surface 22.

  Further, for example, when the HUD unit 10 displays a pattern having a plane image attribute such as a numerical value of the vehicle speed, the display control unit 51 executes S14, so that the two-dimensional display panel 11 is positioned so as not to tilt. Is done. Therefore, in this case, the orientation of the virtual image forming surface 22 faces in the direction orthogonal to the orientation of the line of sight 18, and the driver can visually recognize the virtual image 21 in an untilted state from the front. In this case, the display of the virtual image 21 becomes a flat display equivalent to the screen display of the two-dimensional display panel 11, but good visibility is obtained.

<Possibility of deformation other than the above>
As for the two-dimensional display panel 11, a reflective display panel can be used in addition to the transmissive type and the self-luminous type.

  In the example shown in FIG. 2, the HUD display area 20 and the landscape 30 are arranged so that they overlap each other. However, a combiner (reflecting plate) is arranged at a location adjacent to the windshield 17, for example, on the dashboard. The layout may be changed so that the virtual image 21 appears in the combiner area.

  In the example shown in FIG. 2, since the HUD display area 20 is located below the position Yc corresponding to the infinity point 31, the virtual image formation is performed so that the area upper end 20a is arranged farther than the area lower end 20b. The inclination direction of the image plane 22 is determined. Therefore, when the HUD display area 20 is disposed above the position Yc, it is assumed that the inclination of the virtual image imaging plane 22 is determined so that the lower end 20b of the area is disposed farther than the upper end 20a of the area. Is done.

  In the processing shown in FIG. 6, it is assumed that the orientation of the two-dimensional display panel 11 is positioned at one of two types of positions, but the virtual image 21 is displayed according to the type of pattern to be displayed. Depending on the situation of the scenery that overlaps the area, positioning at various angles may be considered. Further, the tilt angle of the two-dimensional display panel 11 and the virtual image imaging plane 22 may be finely adjusted according to the user's preference by a manual adjustment instruction using a button for receiving a user input.

Here, the features of the above-described embodiment of the vehicle projection display device according to the present invention will be briefly summarized in the following (1) to (5).
(1) Light including an arbitrary display image formed in a planar shape in a predetermined display area (two-dimensional display panel 11) is emitted from the projection unit and guided to the windshield (17) of the vehicle or the vicinity thereof. A projection display device for a vehicle that projects the display image of the light reflected on the windshield or a surface in the vicinity thereof so that the display image can be visually recognized as a virtual image at a predetermined eye point (viewpoint EP),
An inclination adjustment mechanism (55) for adjusting the orientation of the imaging plane of the virtual image (virtual image imaging plane 22) with respect to the orientation of the optical axis (line of sight 18);
The imaging plane whose direction is adjusted by the tilt adjusting mechanism is arranged in a state inclined with respect to a plane orthogonal to the direction of the line of sight (18) connecting the eye point and the virtual image (see FIG. 1). ,
A projection display apparatus for a vehicle characterized by the above.
(2) The vehicle projection display device according to (1) above,
The tilt adjustment mechanism (55) is connected to a support member that supports a display panel (two-dimensional display panel 11) for displaying the display image,
In the state in which the imaging surface (22) is inclined, light emitted from the projection unit is generated using light traveling in the direction of the inclination axis (Z) inclined with respect to the direction perpendicular to the surface of the display panel. (See Fig. 1)
A projection display apparatus for a vehicle characterized by the above.
(3) The vehicle projection display device according to (1) above,
When the information displayed as the virtual image satisfies a predetermined display condition, the tilt adjustment mechanism is driven to position the orientation of the image plane of the virtual image in a predetermined tilt state (S12, S13). Unit (display control unit 51) (see FIGS. 5 and 6),
A projection display apparatus for a vehicle characterized by the above.
(4) The vehicle projection display device according to (3) above,
When the virtual image is arranged at a position lower than the horizontal direction viewed from the eye point, the tilt control unit is configured to reach the upper end of the virtual image compared to the distance from the eye point to the lower end of the virtual image. Adjusting the inclination of the imaging plane of the virtual image in the direction in which the distance becomes larger (see FIG. 7B),
A projection display apparatus for a vehicle characterized by the above.
(5) The vehicle projection display device according to (2) above,
The display panel is a transmissive display device (transmissive liquid crystal display panel 11A),
Furthermore, the backlight (12) for illumination arrange | positioned at the back side of the said two-dimensional display panel is provided (refer FIG. 3),
A projection display apparatus for a vehicle characterized by the above.

DESCRIPTION OF SYMBOLS 10 HUD unit 11 Two-dimensional display panel 11a Display image 11c Rotating shaft 11A Transmission-type liquid crystal display panel 11B Self-light-emitting display panel 12 Backlight 12a Illumination light 13,16 Output light 14 Optical filter 15 Reflector 17 Windshield 18 Line of sight 20 HUD display area 20a area upper end 20b area lower end 21 virtual image 22 virtual image imaging surface 22c rotation axis 30 landscape 30a road surface 30b lane marking on road surface 31 infinity point 51 display control unit 52 nonvolatile memory 53 motor driver 54 electric motor 55 tilt Adjustment mechanism 100 Meter unit 200 Car navigation system A1, A2 area

Claims (5)

The light including an arbitrary display image formed in a planar shape in a predetermined display area is emitted from the projection unit, guided to the windshield of the vehicle or the vicinity thereof, and reflected by the surface of the windshield or the vicinity thereof A projection display device for a vehicle that projects the display image so that it can be visually recognized as a virtual image at a predetermined eye point,
A tilt adjustment mechanism that adjusts the orientation of the imaging plane of the virtual image with respect to the orientation of the optical axis;
The imaging plane whose direction is adjusted by the tilt adjustment mechanism is arranged in a state inclined with respect to a plane orthogonal to the direction of the line of sight connecting the eye point and the virtual image.
A projection display apparatus for a vehicle characterized by the above. The vehicle projection display device according to claim 1,
The tilt adjustment mechanism is connected to a support member that supports a display panel that displays the display image,
In the state in which the imaging plane is inclined, the light emitted from the projection unit is generated using the light directed toward the direction of the inclined axis inclined with respect to the direction perpendicular to the surface of the display panel.
A projection display apparatus for a vehicle, characterized in that The vehicle projection display device according to claim 1,
When the information displayed as the virtual image satisfies a predetermined display condition, the image forming apparatus further includes a tilt control unit that drives the tilt adjustment mechanism to position the orientation of the image plane of the virtual image in a predetermined tilt state. ,
A projection display apparatus for a vehicle characterized by the above. The vehicle projection display device according to claim 3,
When the virtual image is arranged at a position lower than the horizontal direction viewed from the eye point, the tilt control unit is configured to reach the upper end of the virtual image compared to the distance from the eye point to the lower end of the virtual image. Adjusting the inclination of the imaging plane of the virtual image in the direction in which the distance increases.
A projection display apparatus for a vehicle characterized by the above. The vehicle projection display device according to claim 2,
The display panel is a transmissive display device,
A lighting backlight disposed on the back side of the display panel;
A projection display apparatus for a vehicle characterized by the above.

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