JP7769863B2 - Vehicle display device - Google Patents

Description

The present invention relates to a vehicle display device that displays a virtual image.

Various head-up display devices have been proposed in the past that project display light onto a vehicle's windshield to display a virtual image, as disclosed, for example, in Patent Document 1. Such head-up display devices project display light emitted by a display onto the windshield via a projection optical system such as a concave mirror, displaying vehicle information as a virtual image. The driver can view the virtual image, which is superimposed on the actual view ahead of the vehicle.

The above-mentioned head-up display device corrects the distortion of the virtual image caused by the curvature of the windshield by pre-distorting the image displayed on the display. This distortion correction is called pre-distortion. Head-up display devices display various information, such as vehicle speed, navigation information, etc.

Japanese Patent Application Laid-Open No. 2021-103274

However, displaying a large amount of information as a virtual image requires a large field of view for the virtual image, which poses the problem of distortion depending on the position where the display light is projected onto the windshield. The present invention addresses this problem by providing a vehicle display device that can display virtual images with minimal distortion.

The present invention provides a vehicle display device (10) that includes a first display (15) that emits a first display light (L1) and second display devices (51, 52) that emit a second display light (L2), and that displays virtual images (V1, V2, V3) by projecting the first display light (L1) and the second display lights (L2, L3) onto a windshield (13). The vehicle display device (10) includes a first display (15) that emits a first display light (L1) and second display devices (51, 52) that emit a second display light (L2), and that displays virtual images (V1, V2, V3) by projecting the first display light (L1) and the second display lights (L2, L3) onto a windshield (13). The first image (G1) to be displayed on the first display (15) and the second images (G2, G3) to be displayed on the second display devices (51, 52) are set in advance so as to reduce distortion of the virtual images (V1, V2, V3) due to curvature of the windshield (13). The image forming apparatus further includes a control means 180 for distorting the virtual images, the control means 180 generating the first image G1 using a first parameter 211 and generating the second images G2 and G3 using second parameters 212 and 213 , and individually setting the first parameter 211 and the second parameters 212 and 213 so that the amount of distortion of the virtual images V1, V2, and V3 as viewed from each of the partial areas E11 to E55 of a predetermined area divided into partial areas of a matrix is equal to or less than a predetermined threshold, and so that the simple average of the amount of distortion is minimized .

The present invention also provides a vehicle display device (10) that includes a first display (15) that emits a first display light (L1) and second display devices (51, 52) that emit a second display light (L2), and that displays virtual images (V1, V2, V3) by projecting the first display light (L1) and the second display lights (L2, L3) onto a windshield (13), wherein a first image (G1) to be displayed on the first display (15) and second images (G2, G3) to be displayed on the second display devices (51, 52) are adjusted so as to reduce distortion of the virtual images (V1, V2, V3) caused by curvature of the windshield (13). The image processing device further includes a control means 180 for pre-distorting the virtual images, and the control means 180 generates the first image G1 using a first parameter 211 and generates the second images G2 and G3 using second parameters 212 and 213, and is characterized in that the first parameter 211 and the second parameters 212 and 213 are individually set so that the amount of distortion of the virtual images V1, V2, and V3 as viewed from each of the partial areas E11 to E55 of a predetermined area divided into partial areas of a matrix is equal to or less than a predetermined threshold, and the simple average of the amount of distortion is minimized.

The present invention also provides a vehicle display device (10) that includes a first display (15) that emits a first display light (L1) and second display devices (51, 52) that emit a second display light (L2), and that displays virtual images (V1, V2, V3) by projecting the first display light (L1) and the second display lights (L2, L3) onto a windshield (13), wherein a first image (G1) to be displayed on the first display (15) and second images (G2, G3) to be displayed on the second display devices (51, 52) are adjusted so as to reduce distortion of the virtual images (V1, V2, V3) caused by curvature of the windshield (13). The image processing device further includes a control means 180 for pre-distorting the virtual images, and the control means 180 generates the first image G1 using a first parameter 211 and generates the second images G2 and G3 using second parameters 212 and 213, and is characterized in that the first parameter 211 and the second parameters 212 and 213 are individually set so that the amount of distortion of the virtual images V1, V2, and V3 as viewed from each of the partial areas E11 to E55 of a predetermined area divided into partial areas of a matrix is equal to or less than a predetermined threshold, and the weighted average of the amount of distortion is minimized.

The present invention is also characterized in that a first virtual image V1 is displayed by the first display light L1, and multiple second virtual images V2, V3 are displayed on the left and right of the first virtual image V1 by the second display light L2, L3.

By pre-distorting images displayed on multiple displays with individual parameters, it is possible to display a virtual image with minimal distortion.

1 is a cross-sectional view showing an embodiment of the present invention. 2 is a schematic view of the vehicle display device according to the embodiment; FIG. 2 is a schematic view of the vehicle display device according to the embodiment; FIG. FIG. 3A and 3B are explanatory diagrams of an image and a virtual image illustrating the embodiment. 3A and 3B are explanatory diagrams of an image and a virtual image illustrating the embodiment. 3A and 3B are explanatory diagrams of an image and a virtual image illustrating the embodiment. FIG.

An embodiment of the present invention applied to a vehicle display device 10 will be described below with reference to the accompanying drawings.

The display unit 11 is disposed within the dashboard 12 of the vehicle (see Figure 2). The display light L1 projected by the display unit 11 is reflected by the windshield 13 toward the vehicle driver D. The vehicle driver D can view the virtual image V1 superimposed on the real view in a predetermined area E called the eyebox.

The display unit 11 comprises a liquid crystal display 15 and a reflector 16 housed in a housing 17. The liquid crystal display 15 has a liquid crystal display panel 19, a light-emitting diode 20, and a case body 21, and emits display light L1 from a screen 15a. The screen 15a of the liquid crystal display 15 is rectangular, and the vertical direction of the screen 15a corresponds to the up-down direction of the virtual image V. The liquid crystal display panel 19 has a liquid crystal cell 23, a polarizing plate 24, and a polarizing plate 25, and is fixed to the case body 21.

The case body 21 has a roughly rectangular cylindrical shape, and the liquid crystal display panel 19 is held at the front end of the case body 21. The rear end of the case body 21 is fixed to a heat dissipation member, which will be described later. The light-emitting diode 20 is disposed behind the liquid crystal display panel 19 and transmits light to illuminate the liquid crystal display panel 19. The light-emitting diode 20 is mounted on a circuit board 27.

The reflector 16 has a concave mirror 30, a holding member 31, and a stepping motor 32. The concave mirror 30 is made of resin (e.g., polycarbonate) coated with a metal (e.g., aluminum) to form a reflective surface 30a. The reflective surface 30a is concave, and the display light L1 emitted by the LCD 15 is magnified to display a virtual image V1. The concave mirror 30 is adhered to the holding member 31 with double-sided adhesive tape. The holding member 31 is made of resin (e.g., ABS), and the gear portion 34 and shaft portion 35 are formed integrally. The shaft portion 35 of the holding member 31 is journaled to the housing 17.

A gear 37 is attached to the rotation shaft of the stepping motor 32, and this gear 37 meshes with the gear portion 34 of the holding member 31. The concave mirror 30 is supported in a rotatable state together with the holding member 31, and the stepping motor 32 rotates the concave mirror 30, allowing the projection direction of the display light L1 to be adjusted. The vehicle driver D operates push button switches 62, 63 to adjust the angular position of the concave mirror 30 so that the display light L1 is reflected to the eye position (i.e., so that the virtual image V1 can be viewed). The drive mechanism M consists of the stepping motor 32 and gear 37.

Reference numeral 40 denotes a heat dissipation member, which is disposed in the opening 17a of the housing 17. The heat dissipation member 40 is fixed to the housing 17 at the flange portion 40a with screws (not shown). The heat dissipation member 40 dissipates heat from the light-emitting diodes 20 to the outside of the housing 17 via a thermally conductive sheet 41 made of an elastic material such as silicone rubber. The heat dissipation member 40 has a large number of flat heat dissipation fins 40b.

The heat dissipation member 40 has rectangular parallelepiped-shaped protrusions 40c formed on it. The thermally conductive sheet 41 has recesses 41a that correspond to the protrusions 40c on the heat dissipation member 40, increasing the contact area between the thermally conductive sheet 41 and the heat dissipation member 40. 42 is a rectangular, annular packing member that seals the gap between the heat dissipation member 40 and the opening 17a of the housing 17, preventing dust from entering the housing 17.

The housing 17 contains the LCD display 15 and reflector 16. The housing 17 has a window 44 through which the display light L1 exits. This window 44 is made of a light-transmitting resin (e.g., acrylic) and has a curved shape. The housing 17 is provided with a light-shielding wall 17c, which prevents external light such as sunlight from entering the LCD display 15 and making the virtual image V1 difficult to see (washout). The light-shielding wall 17c has a flat plate shape and is formed to hang down diagonally from the top of the housing 17.

The liquid crystal display 51 is comprised of a TFT (Thin Film Transistor) liquid crystal display panel and a backlight that transmits and illuminates the liquid crystal display panel, and is disposed within the vehicle's dashboard 12. The liquid crystal display 51 is located on the left side of the display unit 11. Display light L2 emitted by the liquid crystal display 51 is projected near the bottom edge of the windshield 13, displaying a virtual image V2. The vehicle driver D can view the virtual image V2 superimposed on the real scene. Because the display light L2 emitted by the liquid crystal display 51 is projected onto the windshield 13 without passing through a projection optical system, the imaging distance of the virtual image V2 is shorter than the imaging distance of the virtual image V1.

The liquid crystal display 52 is comprised of a TFT (Thin Film Transistor) liquid crystal display panel and a backlight that transmits and illuminates the liquid crystal display panel, and is disposed within the vehicle's dashboard 12. The liquid crystal display 52 is located to the right of the display unit 11. Display light L3 emitted by the liquid crystal display 52 is projected near the bottom edge of the windshield 13, displaying a virtual image V3. The vehicle driver D can view the virtual image V3 superimposed on the real scene. Because the display light L3 emitted by the liquid crystal display 52 is projected onto the windshield 13 without passing through a projection optical system, the imaging distance of the virtual image V3 is shorter than the imaging distance of the virtual image V1.

Figure 4 is a block diagram showing the electrical configuration of the vehicle display device 10. The vehicle display device 10 has a control unit 180, a non-volatile memory 210, and an image memory 220.

The control unit 180 has a warping control unit 184, a memory control unit 192, and a warping processing unit 194. The control unit 180 drives the liquid crystal display 15 to display image G1 on the screen 15a (see FIG. 5(b)). The control unit 180 also drives the liquid crystal display 51 to display image G2 on the screen 51a (see FIG. 6(b)). The control unit 180 also drives the liquid crystal display 52 to display image G3 on the screen 52a (see FIG. 7(b)). The control unit 180 is connected to an in-vehicle communication bus 300 such as a CAN (Controller Area Network).

Non-volatile memory 210 is a ROM (Read Only Memory), and stores warping parameters 211, 212, and 213. Warping parameter 211 warps the original image temporarily stored in image memory 220 to generate image 15a. Warping parameter 212 warps the original image temporarily stored in image memory 220 to generate image 51a. Warping parameter 213 warps the original image temporarily stored in image memory 220 to generate image 52a.

The warping parameters 211, 212, and 213 are set by any one of the following (1) to (3), and in this embodiment, the warping parameters 211, 212, and 213 are set individually. As shown in Fig. 8, the predetermined region E is divided into partial regions E11 to E55 of 5 rows and 5 columns.
(1) The warping parameters 211, 212, and 213 are set so that the distortion of the virtual images V1, V2, and V3 as viewed from the central partial region E33 of the predetermined region E is minimized.
(2) The warping parameters 211, 212, and 213 are set so that the amount of distortion of the virtual images V1, V2, and V3 as seen from each partial region E11 to E55 is below a predetermined threshold value, and the simple average of the amount of distortion of the virtual images V1, V2, and V3 as seen from each partial region E11 to E55 is minimized.
(3) The warping parameters 211, 212, and 213 are set so that the amount of distortion of the virtual images V1, V2, and V3 as seen from each partial region E11 to E55 is below a predetermined threshold value and the weighted average of the amount of distortion of the virtual images V1, V2, and V3 as seen from each partial region E11 to E55 is minimized.

The image memory 220 is a volatile memory known as a VRAM or video memory, and temporarily stores the original image data 222 before warping, and the image data 224 of the images G1, G2, and G3 warped by the warping processing unit 194 of the control unit 180. The vehicle ECU 340, the external communication unit 360, and the navigation system 370 are connected to the in-vehicle communication bus 300.

The basic operation of the control unit 180 is as follows: The memory control unit 192 accesses the non-volatile memory 210 and reads out the warping parameters 211, 212, and 213. The warping processing unit 194 performs warping processing on the original image using the read out warping parameters 211, 212, and 213, and the image data after warping processing is supplied to the LCD displays 15, 51, and 52.

Image 15a displayed on LCD display 15 is distorted by the influence of concave mirror 30 and windshield 13. Images 51a and 52a displayed on LCD displays 51 and 52 are also distorted by the influence of windshield 13. However, in this embodiment, images G1, G2, and G3 are predistorted by warping processing, so the distortion of virtual images V1, V2, and V3 is small.

In particular, in this embodiment, the warping parameters 211, 212, and 213 are set individually depending on the location on the windshield 13 onto which the display lights L1, L2, and L3 are projected and whether or not a projection optical system is present, so distortion of the virtual images V1, V2, and V3 is small.

The present invention is not limited to this embodiment, and various modifications are possible. For example, the displays in this embodiment are liquid crystal displays 15, 51, and 52, but they may also be DMD projectors.

10 Vehicle display device 13 Windshield 15 Liquid crystal display (first display)
19 Liquid crystal display panel 20 Light emitting diode (light emitting element)
30 Concave mirror (projection optical system)
51 Liquid crystal display (second display)
52 Liquid crystal display (second display)
180 control unit (control means)
211 Warping Parameter (First Parameter)
212 Warping Parameter (Second Parameter)
213 Warping Parameter (Second Parameter)
210 Non-volatile memory G1 Image (first image)
G2 Image (second image)
G3 Image (second image)
L1 display light (first display light)
L2 display light (second display light)
L3 display light (second display light)
V1 Virtual image (first virtual image)
V2 Virtual image (second virtual image)
V3 Virtual image (second virtual image)
D. Vehicle driver

Claims (4)

A vehicle display device including a first display device that emits a first display light and a second display device that emits a second display light, the vehicle display device displaying a virtual image by projecting the first display light and the second display light onto a windshield,
a control unit configured to pre-distort a first image to be displayed on the first display device and a second image to be displayed on the second display device so as to reduce distortion of the virtual image due to curvature of the windshield;
the control means generates the first image using first parameters and generates the second image using second parameters ;
A display device for a vehicle, characterized in that the first parameter and the second parameter are individually set so as to minimize the amount of distortion of the virtual image as seen from a central sub-region of a predetermined region divided into sub-regions in a matrix. A vehicle display device including a first display device that emits a first display light and a second display device that emits a second display light, the vehicle display device displaying a virtual image by projecting the first display light and the second display light onto a windshield,
a control unit configured to pre-distort a first image to be displayed on the first display device and a second image to be displayed on the second display device so as to reduce distortion of the virtual image due to curvature of the windshield;
the control means generates the first image using first parameters and generates the second image using second parameters;
A display device for a vehicle, characterized in that the amount of distortion of the virtual image as seen from each of a predetermined area divided into subareas of a matrix is equal to or less than a predetermined threshold, and the first parameter and the second parameter are individually set so that a simple average of the amount of distortion is minimized. A vehicle display device including a first display device that emits a first display light and a second display device that emits a second display light, the vehicle display device displaying a virtual image by projecting the first display light and the second display light onto a windshield,
a control unit configured to pre-distort a first image to be displayed on the first display device and a second image to be displayed on the second display device so as to reduce distortion of the virtual image due to curvature of the windshield;
the control means generates the first image using first parameters and generates the second image using second parameters;
A vehicle display device characterized in that the amount of distortion of the virtual image as seen from each of a predetermined area divided into subareas in a matrix is equal to or less than a predetermined threshold, and the first parameter and the second parameter are individually set so that a weighted average of the amount of distortion is minimized. 4. The vehicle display device according to claim 1, wherein a first virtual image is displayed by the first display light, and a plurality of second virtual images are displayed to the left and right of the first virtual image by the second display light.