JP2023182076A - Vehicle display system - Google Patents

Abstract

To provide a vehicle display system capable of appropriately displaying a virtual image according to the brightness of a background.SOLUTION: A vehicle display system 1 includes a liquid crystal display device 31, a brightness detection unit 321, and a brightness adjustment unit 322. The liquid crystal display device 31 includes a liquid crystal panel 311 that displays a display image, and a backlight 312 that illuminates the liquid crystal panel 311, and the liquid crystal display device displays a virtual image by emitting display light containing the display image toward a transparent windshield provided in a vehicle. The brightness detection unit 321 detects the brightness of a background on which the virtual image is displayed. The brightness adjustment unit 322 adjusts both of the brightness of the backlight 312 and the brightness of each pixel forming the display image, based on the brightness of the background detected by the brightness detection unit 321.SELECTED DRAWING: Figure 2

Description

The present invention relates to a display system for a vehicle.

BACKGROUND ART Conventionally, as a vehicle display system, for example, Patent Document 1 describes an in-vehicle display device that adjusts the brightness of a virtual image according to the brightness of a background on which the virtual image is displayed. This in-vehicle display device includes, for example, an output section that emits projection light that is a luminous flux containing an image, a reflection section that reflects the projection light to form a virtual image superimposed on an external scene, and a luminance control section that changes the brightness at each point in the background. A brightness acquisition unit that acquires a brightness distribution that is a set; and a high brightness region that is a region that is made up of one or more points and has a brightness higher than the average brightness of each point in the brightness distribution that has been acquired. and a brightness adjustment unit that adjusts the brightness of the virtual image by correcting RGB of the virtual image according to the angle formed by the virtual image and the reference direction.

JP2019-159216A

By the way, the in-vehicle display device described in Patent Document 1 mentioned above adjusts the brightness of the virtual image by correcting RGB of the virtual image according to the brightness of the background, for example, but it is possible to adjust the brightness of the virtual image more appropriately. It is hoped that

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle display system that can appropriately display a virtual image depending on the brightness of the background.

In order to solve the above-mentioned problems and achieve the objects, a vehicle display system according to the present invention includes a liquid crystal panel that displays a display image, and a backlight that irradiates light to the liquid crystal panel, and is installed in a vehicle. a display device that displays a virtual image by irradiating a display light containing the display image toward a reflective member that has transparent properties; a detection unit that detects the brightness of a background on which the virtual image is displayed; and a detection unit that detects the luminance of a background on which the virtual image is displayed; and a brightness adjustment section that adjusts both the brightness of the backlight and the brightness of each pixel constituting the display image based on the brightness of the background.

Since the vehicle display system according to the present invention adjusts both the brightness of the backlight and the brightness of each pixel of the displayed image, it is possible to appropriately adjust the brightness of the virtual image according to the brightness of the background.

FIG. 1 is a schematic diagram showing a configuration example of a vehicle display system according to an embodiment. FIG. 2 is a block diagram showing a configuration example of a vehicle display system according to an embodiment. FIG. 3 is a diagram illustrating an example of adjusting the brightness of the backlight and the brightness of each pixel of the displayed image according to the embodiment. FIG. 4 is a diagram illustrating an example of adjusting the brightness of the backlight according to the embodiment. FIG. 5 is a diagram illustrating an example of adjusting the brightness of each pixel of a display image according to the embodiment. FIG. 6 is a flowchart showing an example of the operation of the vehicle display system according to the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Further, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the present invention.

[Embodiment]
A vehicle display system 1 according to an embodiment will be described with reference to the drawings. The vehicle display system 1 adjusts the brightness of the virtual image Q according to the brightness of the background P on which the virtual image Q is displayed, and includes a viewpoint detection section 10, a camera 20, a HUD (head-up display) device 30, Equipped with The viewpoint detection unit 10, the camera 20, and the HUD device 30 are connected to be able to communicate with each other.

The viewpoint detection unit 10 detects the driver's viewpoint. The viewpoint detection unit 10 is provided in a vehicle, and is disposed at a position facing the driver in the longitudinal direction of the vehicle. The viewpoint detection unit 10 detects the driver's viewpoint, and outputs viewpoint information representing the detected viewpoint to the HUD device 30.

The camera 20 is for capturing images. The camera 20 is installed in the vehicle and captures an image of a background P in front of the vehicle on which the virtual image Q is superimposed. The camera 20 outputs a background image P1 that captures the background P to the HUD device 30.

The HUD device 30 displays a virtual image Q. The HUD device 30 is provided inside the instrument panel of the vehicle, and displays a virtual image Q by emitting display light including a display image P2 toward a transparent windshield F. The HUD device 30 includes a liquid crystal display device 31 and a processing section 32, as shown in FIG. The liquid crystal display device 31 and the processing section 32 are connected to be able to communicate with each other.

The liquid crystal display device 31 displays images and includes a liquid crystal panel 311 and a backlight 312.

The liquid crystal panel 311 displays the display image P2, and is formed in a rectangular shape. The liquid crystal panel 311 includes a liquid crystal, three primary color (RGB) color filters, a polarizing filter, and the like. The liquid crystal panel 311 displays the display image P2 by adjusting the amount of light transmitted through the color filter by controlling the voltage applied to the liquid crystal by the processing unit 32.

The backlight 312 irradiates the liquid crystal panel 311 with light, is formed in a rectangular shape according to the shape of the liquid crystal panel 311, and is installed on the back surface of the liquid crystal panel 311. The backlight 312 includes a plurality of light emitting elements 312a. The plurality of light emitting elements 312a are, for example, LEDs (light emitting diodes), and are arranged in a grid pattern. As shown in FIG. 3, the backlight 312 is divided into a plurality of blocks in units of light emitting blocks B according to each light emitting element 312a. The backlight 312 is divided into, for example, one light emitting block B for one light emitting element 312a. That is, in the backlight 312, one light emitting element 312a and one light emitting block B correspond to each other on a one-to-one basis. The amount of light irradiated from the backlight 312 is adjusted by the processing unit 32 for each light emitting element 312a, and the brightness of the light emitting element 312a is adjusted.

The processing section 32 controls the liquid crystal display device 31. The processing section 32 includes a brightness detection section 321 as a detection section and a brightness adjustment section 322.

The brightness detection unit 321 detects the brightness of the background P on which the virtual image Q is displayed. The brightness detection unit 321 detects the brightness of each pixel of the background image P1 captured by the camera 20. The brightness detection unit 321 outputs the detected brightness of each pixel of the background image P1 to the brightness adjustment unit 322.

The brightness adjustment unit 322 adjusts both the brightness of the backlight 312 and the brightness of each pixel forming the display image P2, based on the brightness of the background P detected by the brightness detection unit 321. Here, the display image P2 is divided into a plurality of display image blocks P21 in units of light emitting blocks B of the backlight 312. The brightness adjustment unit 322 adjusts the brightness of the light emitting element 312a in the display image block P21 and the brightness of each pixel in the display image block P21 based on the brightness of the background P in the display image block P21.

Next, a specific method for adjusting the brightness of the virtual image Q will be described with reference to FIGS. 3 to 5. In this example, as shown in FIG. 3, an example in which an "arrow" and "60 km/h" are displayed as the virtual image Q will be described. The backlight 312 is divided into light-emitting blocks B according to each light-emitting element 312a, for example, into "15" light-emitting blocks B of "3×5". The display image P2 has the same image size as the background image P1 of the background P on which the display image P2 is superimposed and displayed as a virtual image. The display image P2 is divided into "15" display image blocks P21 in units of light emitting blocks B of the backlight 312, and the background image P1 is also divided into "15" background images in units of light emitting blocks B of the backlight 312. It is divided into blocks P11. In the background P, a part of the area M2 has higher luminance than the remaining area M1. In the background P, a part of the "arrow" is displayed overlappingly in the high brightness area M2, and the remaining part of the "arrow" and "60 km/h" are displayed overlappingly in the low brightness area M1. .

In the above display mode, the brightness detection unit 321 detects the brightness of each pixel of the background image P1 captured by the camera 20. For example, as shown in FIG. 4, the brightness detection unit 321 detects the brightness of each pixel of the background image P1 for each background image block P11. Then, the brightness detection unit 321 detects the maximum brightness from each pixel of each background image block P11. In the example shown in FIG. 4, the brightness detection unit 321 detects the maximum brightness "250" from each pixel of the predetermined background image block P11. Similarly, the brightness detection unit 321 detects the maximum brightness of each pixel for the other background image blocks P11, and as shown in FIG. A maximum brightness table N1 is generated. This maximum brightness table N1 corresponds to, for example, the background image P1a shown in FIG. 3. This background image P1a includes an area M2 (a "3x1" block) where the background brightness is relatively high and an area M1 (a "3x4" block) where the background brightness is relatively low.

The brightness adjustment unit 322 turns on the backlight 312 for a range E1 where an "arrow" is displayed as the virtual image Q (see FIG. 3) and a range E2 where "60 km/h" is displayed, and on the other hand, a range where the virtual image Q is not displayed. , the backlight 312 is turned off. The brightness adjustment unit 322 uses the maximum brightness table N1 of the background image P1 generated by the brightness detection unit 321 to adjust the brightness of the light emitting elements 312a of the backlight 312 in the ranges E1 and E2 in which the backlight 312 is turned on. For example, as shown in FIG. 4, the brightness adjustment unit 322 has map data of a dimming curve that represents the relationship between the background brightness of the background image P1 and the backlight brightness. The dimming curve makes the backlight brightness relatively high when the background brightness is relatively high, and makes the backlight brightness relatively low when the background brightness is relatively low. The brightness adjustment unit 322 individually adjusts the brightness of the light emitting elements 312a of the backlight 312 for each light emitting block B based on this dimming curve.

The brightness adjustment unit 322 calculates the brightness of the light emitting element 312a corresponding to the maximum brightness of the background image block P11 represented by the maximum brightness table N1, for example, based on the dimming curve. Then, the brightness adjustment unit 322 generates a brightness table N2 of the light emitting element 312a in which the calculated brightness of the light emitting element 312a is recorded. In the brightness table N2 of the light emitting elements 312a, the brightness of the light emitting elements 312a is recorded for each light emitting block B. The brightness adjustment unit 322 adjusts the brightness of each light emitting element 312a of the backlight 312 based on this brightness table N2, and adjusts the amount of light irradiated for each light emitting element 312a. In this example, the brightness adjustment unit 322 adjusts the brightness of the light emitting element 312a in an area M2 (a "3x1" block) where the background brightness is relatively high regarding ranges E1 and E2 in the background image P1a where the backlight 312 is turned on. The brightness of the light emitting element 312a in the area M1 ("3x4" block) where the background brightness is relatively low is made relatively high. The backlight 312 emits light from each light emitting element 312a with the brightness adjusted by the brightness adjustment section 322.

Next, an example of correcting the brightness (RGB brightness) of each pixel forming the display image P2 will be described. The brightness adjustment unit 322 corrects the brightness (RGB brightness) of each pixel forming the display image P2 by adjusting the voltage applied to the liquid crystal of the liquid crystal panel 311. The brightness adjustment unit 322 adjusts the brightness of each pixel of the display image block P21, for example, based on the brightness of the background P in the display image block P21. For example, the brightness adjustment unit 322 integrates a value obtained by dividing the brightness of each pixel constituting the area of the background image P1 by the maximum brightness in the area of the background image P1 to the brightness of each pixel of the corresponding display image P2. , corrects the brightness of each pixel of the display image P2. That is, as shown in FIG. 5, the brightness adjustment unit 322 divides the brightness (for example, 69) of each pixel constituting the background image block P11 by the maximum brightness (for example, "250") in the background image block P11. The value is integrated with the luminance (for example, "0") of the pixel of the corresponding display image block P21 to correct the luminance of the pixel of the display image block P21. The display image block P21a shown in FIG. 5 is a table in which the brightness of each pixel after correction is recorded. In this way, in each display image block P21, the brightness adjustment unit 322 corrects the brightness (RGB brightness) of each pixel constituting the display image block P21 on a pixel-by-pixel basis based on the brightness of the corresponding background image block P11. .

In this way, the brightness adjustment unit 322 adjusts the brightness of the light emitting element 312a of the light emitting block B corresponding to the display image block P21 based on the brightness of the background P in the display image block P21, and the brightness of each pixel of the display image block P21. Adjust both the brightness and brightness.

Next, an example of the operation of the vehicle display system 1 will be described. The vehicle display system 1 acquires a background image P1 from the camera 20 (step S1). Next, the brightness detection unit 321 extracts the maximum brightness for each light emitting block B of the backlight 312 from the background image P1 (step S2). The brightness detection unit 321, for example, detects the maximum brightness among each pixel in each background image block P11, and generates a maximum brightness table N1 in which the maximum brightness of each background image block P11 is detected. Next, the brightness adjustment unit 322 calculates the backlight brightness relative to the background brightness from the dimming curve (step S3). The brightness adjustment unit 322 calculates the brightness of the light emitting element 312a corresponding to the maximum brightness of the background image block P11 represented by the maximum brightness table N1, for example, based on the dimming curve. Then, the brightness adjustment unit 322 generates a brightness table N2 of the light emitting element 312a in which the calculated brightness of the light emitting element 312a is recorded. The brightness adjustment unit 322 adjusts the brightness of each light emitting element 312a of the backlight 312 based on this brightness table N2, and adjusts the amount of light irradiated for each light emitting element 312a. Further, the brightness adjustment unit 322 corrects the brightness of the pixels of the display image P2 (step S4). For example, the brightness adjustment unit 322 integrates a value obtained by dividing the brightness of each pixel constituting the background image block P11 by the maximum brightness in the background image block P11 to the brightness of the pixel in the corresponding display image block P21, and displays the result. The brightness of pixels in image block P21 is corrected.

As described above, the vehicle display system 1 according to the embodiment includes the liquid crystal display device 31, the brightness detection section 321, and the brightness adjustment section 322. The liquid crystal display device 31 includes a liquid crystal panel 311 that displays a display image P2, and a backlight 312 that irradiates light to the liquid crystal panel 311, and displays the display image P2 toward a windshield F that is provided in the vehicle and has transparency. The virtual image Q is displayed by irradiating the display light containing the virtual image Q. The brightness detection unit 321 detects the brightness of the background P on which the virtual image Q is displayed. The brightness adjustment unit 322 adjusts both the brightness of the backlight 312 and the brightness of each pixel forming the display image P2 based on the brightness of the background P detected by the brightness detection unit 321.

With this configuration, the vehicle display system 1 adjusts both the brightness of the backlight 312 and the brightness of each pixel of the display image P2. The resolution can be increased compared to the case where only one of the two is adjusted. Thereby, the vehicle display system 1 can accurately adjust the brightness of the virtual image Q based on the brightness of the background P. As a result, the brightness of the virtual image Q can be adjusted appropriately according to the brightness of the background P. be able to.

In the vehicle display system 1, the backlight 312 includes a plurality of light emitting elements 312a that emit light, and is divided into a plurality of light emitting blocks B according to each light emitting element 312a. The display image P2 is divided into a plurality of display image blocks P21 in units of light emitting blocks B of the backlight 312. The brightness adjustment unit 322 adjusts the brightness of the light emitting element 312a of the light emitting block B corresponding to the display image block P21 and the brightness of each pixel of the display image block P21 based on the brightness of the background P in the display image block P21. With this configuration, the vehicle display system 1 can clearly display the virtual image Q by increasing the brightness of the light emitting element 312a of the light emitting block B corresponding to the display image block P21 in which the background P has relatively high brightness. . The vehicle display system 1 achieves clear display of the virtual image Q and saves power by lowering the brightness of the light emitting element 312a of the light emitting block B corresponding to the display image block P21 where the brightness of the background P is relatively low. can be realized. Furthermore, by adjusting the brightness of each pixel of the display image block P21, the vehicle display system 1 can subdivide and adjust the brightness within the display image block P21, and as a result, according to the brightness of the background P. The brightness of the virtual image Q can be adjusted accurately.

In the vehicle display system 1, the brightness adjustment unit 322 divides the brightness of each pixel constituting the area of the background image P1 by the maximum brightness in the area of the background image P1, and calculates the value of the brightness of each pixel of the corresponding display image P2. The brightness of each pixel of the display image P2 is adjusted by integrating the brightness. With this configuration, the vehicle display system 1 can appropriately adjust the brightness of each pixel of the display image P2 according to the brightness of the background image P1.

Note that in the above description, an example has been described in which the brightness of the light emitting element 312a is adjusted for each light emitting block B, and the brightness of each pixel is adjusted for each display image block P21, but the invention is not limited to this. No need to adjust brightness.

The brightness adjustment unit 322 integrates a value obtained by dividing the brightness of each pixel constituting the area of the background image P1 by the maximum brightness in the area of the background image P1 to the brightness of each pixel of the corresponding display image P2, and adjusts the value of the displayed image. Although an example in which the brightness of each pixel of display image P2 is adjusted has been described, the present invention is not limited to this, and the brightness of each pixel of display image P2 may be adjusted using other calculation methods.

Although an example has been described in which the backlight 312 is divided into one light emitting block B for one light emitting element 312a, the invention is not limited to this, and for example, one light emitting block B is divided for a plurality of light emitting elements 312a. It may be divided into sections.

1 Vehicle display system 20 Camera (detection unit)
31 Liquid crystal display device (display device)
311 Liquid crystal panel 312 Backlight 312a Light emitting element 321 Brightness detection section (detection section)
322 Brightness adjustment section B Light emitting block F Windshield (reflective member)
P Background P2 Display image P21 Display image block Q Virtual image

Claims (3)

A virtual image is displayed by irradiating display light including the display image toward a transmissive reflective member provided on the vehicle, including a liquid crystal panel that displays a display image, and a backlight that irradiates light to the liquid crystal panel. an indicator to
a detection unit that detects the brightness of a background on which the virtual image is displayed;
A brightness adjustment unit for adjusting both the brightness of the backlight and the brightness of each pixel forming the display image based on the brightness of the background detected by the detection unit. display system. The backlight includes a plurality of light emitting elements that emit light, and is divided into a plurality of light emitting blocks according to each of the light emitting elements,
The display image is divided into a plurality of display image blocks in units of the light emitting blocks of the backlight,
The brightness adjustment unit adjusts the brightness of the light emitting element of the light emitting block corresponding to the display image block and the brightness of each pixel of the display image block based on the brightness of the background in the display image block. 1. The vehicle display system according to 1. The brightness adjustment unit integrates a value obtained by dividing the brightness of each pixel forming the background by the maximum brightness of the background to the brightness of each pixel of the corresponding display image, and adjusts the brightness of each pixel of the display image. 3. The vehicle display system according to claim 1, wherein the display system adjusts the brightness of the display system.

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