Vehicle display system

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

[[TECHNICAL FIELD]]

[0001] The present invention relates to a vehicle display system. [[BACKGROUND ART]]

[0002] 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: an emission unit that emits projection light which is a light beam containing an image; a reflection unit that reflects the projection light to form a virtual image superimposed on an outside scene; a brightness acquisition unit that acquires a brightness distribution which is a set of brightness at each point of the background; and a brightness adjustment unit that corrects RGB of the virtual image to adjust the brightness of the virtual image according to an angle formed between a high brightness region and a reference direction, wherein the high brightness region is a region composed of one or more points in the acquired brightness distribution and has a brightness higher than an average brightness of each point. [[PRIOR ART DOCUMENTS]] [[PATENT DOCUMENTS]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2019-159216 [[SUMMARY OF THE INVENTION]] [[Problem to be Solved by the Invention]]

[0004] By the way, the in-vehicle display device described in the above-mentioned Patent Document 1 corrects RGB of the virtual image to adjust the brightness of the virtual image according to the brightness of the background, but it is desired to adjust the brightness of the virtual image more appropriately.

[0005] Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle display system capable of appropriately displaying a virtual image according to the brightness of the background. [[Means for Solving the Problem]]

[0006] To solve the above-mentioned problems and achieve the objective, the vehicle display system according to the present invention is characterized by comprising: a liquid crystal panel for displaying a display image; a backlight for irradiating light onto the liquid crystal panel; a display unit for irradiating display light including the display image toward a transparent reflective member provided on the vehicle to display a virtual image; a detection unit for detecting the brightness of the background on which the virtual image is displayed; and a brightness adjustment unit for adjusting both the brightness of the backlight and the brightness of each pixel constituting the display image based on the brightness of the background detected by the detection unit. [Effects of the Invention]

[0007] The vehicle display system according to the present invention adjusts both the brightness of the backlight and the brightness of each pixel of the display image, so that the brightness of the virtual image can be appropriately adjusted according to the brightness of the background. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of the configuration of a vehicle display system according to an embodiment. [Figure 2] Figure 2 is a block diagram showing an example configuration of a vehicle display system according to an embodiment. [Figure 3] Figure 3 shows an example of adjusting the brightness of the backlight and the brightness of each pixel in the displayed image according to the embodiment. [Figure 4] Figure 4 shows an example of adjusting the brightness of the backlight according to the embodiment. [Figure 5] Figure 5 shows an example of adjusting the brightness of each pixel in the display image according to the embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the operation of a vehicle display system according to the embodiment. [Modes for carrying out the invention]

[0009] 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. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0010] [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 comprises a viewpoint detection unit 10, a camera 20, and a HUD (head-up display) device 30. The viewpoint detection unit 10, the camera 20, and the HUD device 30 are connected to each other so as to be able to communicate with one another.

[0011] The viewpoint detection unit 10 detects the driver's viewpoint. The viewpoint detection unit 10 is installed in the vehicle and positioned opposite the driver in the front-rear 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.

[0012] Camera 20 is used to capture images. Camera 20 is installed on the vehicle and captures the background P in front of the vehicle onto which the virtual image Q is superimposed. Camera 20 outputs the background image P1, which is the background P captured, to the HUD device 30.

[0013] The HUD device 30 displays a virtual image Q. The HUD device 30 is installed inside the instrument panel of the vehicle and displays the virtual image Q by irradiating display light containing a display image P2 toward the transparent windshield F. As shown in Figure 2, the HUD device 30 comprises a liquid crystal display device 31 and a processing unit 32. The liquid crystal display device 31 and the processing unit 32 are connected to each other so as to be able to communicate with each other.

[0014] The liquid crystal display device 31 displays an image and is configured to include a liquid crystal panel 311 and a backlight 312.

[0015] The liquid crystal panel 311 displays a display image P2 and is formed in a rectangular shape. The liquid crystal panel 311 is configured to include liquid crystal, color filters of three primary colors (RGB), polarizing filters, and the like. The liquid crystal panel 311 displays the display image P2 by adjusting the amount of light transmitted through the color filters, through controlling the voltage applied to the liquid crystal by the processing unit 32.

[0016] The backlight 312 irradiates the liquid crystal panel 311 with light, is formed in a rectangular shape matching the shape of the liquid crystal panel 311, and is installed on the back surface of the liquid crystal panel 311. The backlight 312 is configured to include 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 corresponding to each light emitting element 312a. For example, the backlight 312 is divided into 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 have a one-to-one correspondence. In the backlight 312, the processing unit 32 adjusts the light irradiation amount for each light emitting element 312a, thereby adjusting the luminance of the light emitting element 312a.

[0017] The processing unit 32 controls the liquid crystal display device 31. The processing unit 32 includes a luminance detection unit 321 serving as a detection unit, and a luminance adjustment unit 322.

[0018] The luminance detection unit 321 detects the luminance of a background P on which a virtual image Q is displayed. The luminance detection unit 321 detects the luminance of each pixel of a background image P1 captured by the camera 20. The luminance detection unit 321 outputs the detected luminance of each pixel of the background image P1 to the luminance adjustment unit 322.

[0019] The luminance adjusting unit 322 adjusts both the luminance of the backlight 312 and the luminance of each pixel constituting the display image P2 based on the luminance of the background P detected by the luminance detecting unit 321. Here, the display image P2 is divided into a plurality of display image blocks P21 in units of the light-emitting blocks B of the backlight 312. The luminance adjusting unit 322 adjusts the luminance of the light-emitting element 312a in the display image block P21 and the luminance of each pixel of the display image block P21 based on the luminance of the background P in the display image block P21.

[0020] Next, a specific method for adjusting the luminance of a 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 in units of light-emitting blocks B according to each light-emitting element 312a, and for example, is divided into "15" light-emitting blocks B arranged in a "3×5" configuration. 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 for virtual image display. The display image P2 is divided into "15" display image blocks P21 in units of the light-emitting blocks B of the backlight 312, and the background image P1 is also divided into "15" background image blocks P11 in units of the light-emitting blocks B of the backlight 312. A partial region M2 of the background P has higher luminance than the remaining region M1. In the background P, a part of the "arrow" is superimposed and displayed on the high-luminance region M2, and the remaining part of the "arrow" and "60 km / h" are superimposed and displayed on the low-luminance region M1.

[0021] In the display configuration described above, the luminance detection unit 321 detects the luminance of each pixel of the background image P1 captured by the camera 20. The luminance detection unit 321 detects the luminance of each pixel of the background image P1 for each background image block P11, for example, as shown in Figure 4. The luminance detection unit 321 then detects the maximum luminance from among the pixels of each background image block P11. In the example shown in Figure 4, the luminance detection unit 321 detects a maximum luminance of "250" from among the pixels of a predetermined background image block P11. Similarly, the luminance detection unit 321 detects the maximum luminance from among the pixels of other background image blocks P11 and generates a maximum luminance table N1 that detects the maximum luminance of each background image block P11, as shown in Figure 4. This maximum luminance table N1 corresponds to, for example, the background image P1a shown in Figure 3. This background image P1a includes a region M2 ("3×1" block) with relatively high background luminance and a region M1 ("3×4" block) with relatively low background luminance.

[0022] The brightness adjustment unit 322 illuminates the backlight 312 in the range E1 (see Figure 3) where the virtual image Q is an "arrow" and in the range E2 where "60km / h" is displayed, while turning off the backlight 312 in the range where the virtual image Q is not displayed. In the ranges E1 and E2 where the backlight 312 is illuminated, the brightness adjustment unit 322 adjusts the brightness of the light-emitting elements 312a of the backlight 312 using the maximum brightness table N1 of the background image P1 generated by the brightness detection unit 321. The brightness adjustment unit 322 has, for example, map data of a dimming curve that represents the relationship between the background brightness of the background image P1 and the backlight brightness, as shown in Figure 4. The dimming curve increases the backlight brightness relatively when the background brightness is relatively high, and decreases the backlight brightness relatively when the background brightness is relatively low. Based on this dimming curve, the brightness adjustment unit 322 individually adjusts the brightness of the light-emitting elements 312a of the backlight 312 in units of light-emitting blocks B.

[0023] 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 a dimming curve. Then, the brightness adjustment unit 322 generates a brightness table N2 for the light-emitting elements 312a, which records the calculated brightness of the light-emitting elements 312a. The brightness table N2 for the light-emitting elements 312a records the brightness of the light-emitting elements 312a in units of light-emitting block B. Based on this brightness table N2, the brightness adjustment unit 322 adjusts the brightness of each light-emitting element 312a of the backlight 312, and adjusts the amount of light emitted for each light-emitting element 312a. In this example, with respect to ranges E1 and E2 in the background image P1a where the backlight 312 is lit, the brightness of the light-emitting elements 312a in the region M2 ("3×1" block) where the background brightness is relatively high is relatively increased, and the brightness of the light-emitting elements 312a in the region M1 ("3×4" block) where the background brightness is relatively low is relatively decreased. The backlight 312 emits light from each light-emitting element 312a at a brightness adjusted by the brightness adjustment unit 322.

[0024] Next, an example of correcting the brightness (RGB brightness) of each pixel constituting the display image P2 will be described. The brightness adjustment unit 322 corrects the brightness (RGB brightness) of each pixel constituting the display image P2 by adjusting the voltage applied to the liquid crystal of the liquid crystal panel 311. For example, the brightness adjustment unit 322 adjusts 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. For example, the brightness adjustment unit 322 divides the brightness of each pixel constituting the region of the background image P1 by the maximum brightness in the region of the background image P1 and sets the brightness of each pixel in the corresponding display image P2. Multiplication Then, the brightness of each pixel in the displayed image P2 is corrected. That is, as shown in Figure 5, the brightness adjustment unit 322 divides the brightness of each pixel constituting the background image block P11 (for example, 69) by the maximum brightness in the background image block P11 (for example, "250") and sets the brightness of the corresponding pixel in the displayed image block P21 (for example, "0"). MultiplicationThe brightness of the pixels in the display image block P21 is then corrected. The display image block P21a shown in Figure 5 is a table in which the brightness of each pixel after correction is recorded. In this way, 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.

[0025] In this way, the brightness adjustment unit 322 adjusts both 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.

[0026] 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 from among the pixels in each background image block P11 and generates a maximum brightness table N1 in which the maximum brightness of each background image block P11 has been 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, for example, calculates the brightness of the light-emitting element 312a corresponding to the maximum brightness of the background image block P11 represented in the maximum brightness table N1, 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 has been recorded. The brightness adjustment unit 322 adjusts the brightness of each light-emitting element 312a of the backlight 312 based on the brightness table N2, and adjusts the amount of light emitted for each light-emitting element 312a. Furthermore, 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 divides the brightness of each pixel constituting the background image block P11 by the maximum brightness in the background image block P11 and sets the brightness of the corresponding pixels in the display image block P21 to the value obtained by the brightness of each pixel constituting the background image block P11. Multiplication Then, the brightness of the pixels in the displayed image block P21 is corrected.

[0027] As described above, the vehicle display system 1 according to the embodiment comprises 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 P2 and a backlight 312 that irradiates light onto the liquid crystal panel 311. It displays a virtual image Q by irradiating display light, including the display image P2, toward a transparent windshield F provided on the vehicle. 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 constituting the display image P2 based on the brightness of the background P detected by the brightness detection unit 321.

[0028] 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, thus achieving higher resolution compared to conventional systems that adjust only one of either the brightness of the backlight 312 or the brightness of each pixel of the display image P2. As a result, the vehicle display system 1 can accurately adjust the brightness of the virtual image Q based on the brightness of the background P, and consequently, the brightness of the virtual image Q can be appropriately adjusted according to the brightness of the background P.

[0029] In the above-described 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 elements 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 display the virtual image Q clearly by increasing the brightness of the light-emitting elements 312a of the light-emitting block B corresponding to the display image block P21 where the brightness of the background P is relatively high. The vehicle display system 1 can achieve power saving by reducing the brightness of the light-emitting elements 312a of the light-emitting block B corresponding to the display image block P21 where the brightness of the background P is relatively low, after achieving a clear display of the virtual image Q. Furthermore, the vehicle display system 1 can also adjust the brightness of each pixel in the display image block P21, thereby subdividing and adjusting the brightness within the display image block P21. As a result, the brightness of the virtual image Q can be precisely adjusted according to the brightness of the background P.

[0030] In the above-described vehicle display system 1, the brightness adjustment unit 322 adjusts the brightness of each pixel constituting the region of the background image P1 by the maximum brightness in the region of the background image P1, and sets the value obtained by this adjustment to the brightness of each pixel in the corresponding display image P2. Multiplication Then, the brightness of each pixel in the display image P2 is adjusted. With this configuration, the vehicle display system 1 can appropriately adjust the brightness of each pixel in the display image P2 according to the brightness of the background image P1.

[0031] In the above explanation, we described an example 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. However, the explanation is not limited to this, and for example, it is not necessary to adjust the brightness for each block.

[0032] The brightness adjustment unit 322 divides the brightness of each pixel constituting the region of the background image P1 by the maximum brightness in the region of the background image P1 and sets the brightness of each pixel in the corresponding display image P2. Multiplication The above describes an example of adjusting the brightness of each pixel in the displayed image P2, but the method is not limited to this, and the brightness of each pixel in the displayed image P2 may be adjusted by other calculation methods.

[0033] Although an example has been described in which the backlight 312 is divided into one light-emitting block B for each light-emitting element 312a, it is not limited to this, and for example, multiple light-emitting elements 312a may be divided into one light-emitting block B. [Explanation of Symbols]

[0034] 1. Vehicle display system 20 Camera (detection unit) 31 Liquid crystal display device (display device) 311 LCD panel 312 Backlight 312a Light-emitting element 321 Brightness detection unit (detection unit) 322 Brightness adjustment section B Light-emitting block F Windshield (reflective material) P background P2 Display Image P21 Display Image Block Q Illusion

Claims

[Claim 1] A display device that includes a liquid crystal panel for displaying an image and a backlight for irradiating light onto the liquid crystal panel, and irradiates display light including the display image toward a transparent reflective member provided on the vehicle to display a virtual image, A detection unit captures the background on which the virtual image is displayed and detects the brightness of each pixel in the captured background image. The system includes a brightness adjustment unit 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 image detected by the detection unit. 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, based on the light-emitting blocks of the backlight. The background image is divided into multiple background image blocks based on 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 background image block and the brightness of each pixel of the display image block based on the brightness of the background image block. The vehicle display system is characterized in that the brightness adjustment unit detects the maximum brightness from among the pixels of each background image block for each background image block, and adjusts the brightness of each pixel of the display image block by multiplying the value obtained by dividing the maximum brightness of the target background image block by the highest brightness among the maximum brightness of each of the multiple background image blocks by the brightness of each pixel of the display image block corresponding to the target background image block.

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