JP6105531B2 - Projection display device for vehicle - Google Patents

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.

  Thus, if the HUD display image can be displayed with a sense of 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.

  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, and to provide a perspective that matches the scenery outside the vehicle reflected in a position overlapping the display image or in an adjacent position. An object of the present invention is to provide a vehicle projection display device that can be formed.

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 ( 3 ).
(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,
The imaging plane of the virtual image is arranged in a state inclined with respect to a plane perpendicular to the direction of the line of sight connecting the eye point and the virtual image ,
Light emitted from the projection unit using light that is disposed in a state where the display panel that displays the display image is inclined and that is directed toward the direction of an inclination axis that is inclined with respect to a direction perpendicular to the surface of the display panel. Produces
The display panel is a self-luminous display device,
An optical filter disposed on the front side of the display panel;
The optical filter has a characteristic of transmitting light traveling in the direction of the tilt axis whose direction is inclined with respect to a direction perpendicular to the surface of the display panel, and blocking light traveling in a direction other than the direction of the tilt axis. ,
A projection display apparatus for a vehicle characterized by the above.
(2) The vehicle projection display device according to (1) above,
The self-luminous display device is an organic EL display panel.
A projection display apparatus for a vehicle characterized by the above.
( 3 ) The vehicle projection display device according to (1) or (2) above ,
The virtual image is arranged at a position below the horizontal direction viewed from the eye point,
At least the surface of the virtual image is inclined in a direction in which the distance from the eye point to the upper end of the virtual image is larger than the distance from the lower end of the virtual image.
A projection display apparatus for a vehicle characterized by the above.

According to the vehicle projection display apparatus having the configuration (1) or (2) , the image plane of the virtual image to be displayed is inclined with respect to a plane orthogonal to the direction of the line of sight. Therefore, the distance between the eye point corresponding to the position of the driver's viewpoint and the virtual image differs between the lower end and the upper end of the virtual image. That is, even if a special stereoscopic image is not displayed, a perspective, that is, a depth corresponding to the difference in the vertical position is generated for each region on the virtual image. It is also possible to match the perspective on the virtual image with the perspective in the actual landscape.
Further , according to the vehicle projection display device having the configuration ( 1 ) or (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. The imaging plane of the virtual image can be arranged so as to be inclined with respect to a plane orthogonal to the direction of the line of sight. That is, by arranging the display panel in an inclined state, the image plane of the virtual image can also be inclined.
In addition , according to the vehicle projection display device having the configuration of ( 1 ) or (2) , the light necessary for displaying the virtual image is tilted even when the display panel is tilted. Emission can be efficiently performed in the direction of the axis, and high-intensity virtual image display becomes possible.
According to the vehicle projection display device having the above configuration ( 3 ), the difference in perspective in the vertical direction on the inclined virtual image is the difference in perspective when the road surface 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 device of the present invention, it is possible to form a sense of perspective according to the scenery outside the vehicle reflected in a position overlapping with or adjacent to the display image while suppressing an increase in cost of the device. That is, even if a stereoscopic image is not formed, a desired perspective can be obtained by tilting the surface of the displayed virtual image.

  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. 1 is an optical path diagram showing an optical path of each part in a state where a vehicle equipped with a vehicle projection display device is viewed from the side. 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.

  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. 1 shows an outline of the layout and optical paths of each part 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. The vehicle projection display device of the present embodiment constitutes a head-up display (HUD).

  The HUD unit 10 shown in FIG. 1 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 vehicle) The virtual image 21 which is a display image can be visually recognized.

  A characteristic matter in the configuration shown in FIG. 1 is that the direction of the virtual image forming surface 22 is inclined with respect to the direction orthogonal to the line of sight 18. Further, in order to form the inclined virtual image forming surface 22, the orientation of the two-dimensional display panel 11 shown in FIG. Further, the optical axis of the emitted light 13 is also inclined with respect to the direction perpendicular to the surface of the two-dimensional 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>
As shown in FIG. 2, the HUD display area 20 in which the virtual image 21 is displayed has a trapezoidal shape. That is, the width of the region upper end 20a in the X direction 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. That is, 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.

  As shown in FIG. 3, the surface of the flat transmissive liquid crystal display panel 11A is fixed in a state inclined 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 content of the display image 11a, and the illumination light 12a is emitted in the Z direction as emitted light 13.

  Since the transmissive liquid crystal display panel 11A is inclined, the points P1, P2, and P3 at different positions on the display image 11a are present 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.

<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 surface of the planar self-luminous display panel 11 </ b> B is fixed 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.

<Possibility of deformation other than the above>
In the projection display apparatus for a vehicle shown in FIG. 1, it is assumed that the position and the inclination angle of the two-dimensional display panel 11 are fixed. However, an adjustment mechanism is provided so that the position and the inclination angle are manually adjusted appropriately. You may comprise so that it can correct. Thereby, the display position of the virtual image 21 can be adjusted according to the change in the position of the viewpoint EP, or the perspective (depth) of the virtual image 21 can be adjusted according to the preference of the user (driver).

  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.

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 is emitted from the projection unit (HUD unit 10) and guided to the windshield (17) of the vehicle or the vicinity thereof, and the window A projection display device for a vehicle that projects a display image of the light reflected by a shield or a surface in the vicinity thereof so as to be visible as a virtual image (21) at a predetermined eye point (viewpoint EP),
The virtual image imaging plane (virtual image imaging plane 22) 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.
A projection display apparatus for a vehicle characterized by the above.
(2) The vehicle projection display device according to (1) above,
The display panel (two-dimensional display panel 11) that displays the display image is disposed in an inclined state, and the light directed in the direction of the tilt axis (Z) whose direction is inclined with respect to the direction perpendicular to the surface of the display panel. Use to generate light emitted from the projection unit,
A projection display apparatus for a vehicle characterized by the above.
(3) 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 display panel is provided,
A projection display apparatus for a vehicle characterized by the above.
(4) The vehicle projection display device according to (2) or (3) above,
An optical filter (14) disposed on the front side of the display panel;
The optical filter selectively transmits light directed in a direction of an inclination axis (Z) whose direction is inclined with respect to a direction perpendicular to a surface of the display panel;
A projection display apparatus for a vehicle characterized by the above.
(5) The vehicle projection display device according to any one of (1) to (4),
The virtual image is disposed at a position (A1) below the horizontal direction viewed from the eye point (EP),
At least the surface of the virtual image is inclined in a direction in which the distance from the eye point to the upper end (region upper end 20a) of the virtual image is larger than the distance from the lower end (region lower end 20b) of the virtual image.
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 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 Upper end of region 20b Lower end of region 21 Virtual image 22 Virtual image forming plane 30 Landscape 30a Road surface 30b Lane marking on road surface 31 Infinite point A1, A2 region

Claims (3)

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,
The imaging plane of the virtual image is arranged in a state inclined with respect to a plane perpendicular to the direction of the line of sight connecting the eye point and the virtual image ,
Light emitted from the projection unit using light that is disposed in a state where the display panel that displays the display image is inclined and that is directed toward the direction of an inclination axis that is inclined with respect to a direction perpendicular to the surface of the display panel. Produces
The display panel is a self-luminous display device,
An optical filter disposed on the front side of the display panel;
The optical filter has a characteristic of transmitting light traveling in the direction of the tilt axis whose direction is inclined with respect to a direction perpendicular to the surface of the display panel, and blocking light traveling in a direction other than the direction of the tilt axis. ,
A projection display apparatus for a vehicle characterized by the above.   The vehicle projection display device according to claim 1,
  The self-luminous display device is an organic EL display panel.
  A projection display apparatus for a vehicle characterized by the above. The vehicle projection display device according to claim 1 or 2 ,
The virtual image is arranged at a position below the horizontal direction viewed from the eye point,
At least the surface of the virtual image is inclined in a direction in which the distance from the eye point to the upper end of the virtual image is larger than the distance from the lower end of the virtual image.
A projection display apparatus for a vehicle characterized by the above.

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