Display control system, circuit arrangement, and display system

Abstract

The present application provides display control system, circuit device and display system. The display control system includes: processing device, which calculates global dimming information for global dimming control of backlight source of display device, and performs color correction of image data based on the global dimming information; and circuit device, which performs display control of display device based on image data from the processing device. The circuit device includes: dimming control circuit, which calculates local dimming information for local dimming control of backlight source based on image data and global dimming information from the processing device; and light source control circuit, which performs light source control of backlight source based on local dimming information from the dimming control circuit.

Description

Technical Field

[0001] This invention relates to display control systems, circuit devices, and display systems. Background Technology

[0002] In display devices, global dimming control is performed based on detection information from external light sensors, etc. Additionally, Patent Document 1 discloses a display device that performs local dimming control for each of multiple light sources.

[0003] Patent Document 1: International Publication No. 2021 / 241066 Summary of the Invention

[0004] However, to date, no display control system has been proposed that can achieve both global dimming control and local dimming control without significantly altering the existing system.

[0005] One aspect of the present invention relates to a display control system comprising: a processing device that computes global dimming information and performs color correction of image data based on the global dimming information, the global dimming information being used for global dimming control of the backlight of a display device having a display panel and a backlight; and a circuit device that performs display control of the display device based on the image data from the processing device, the circuit device comprising: a dimming control circuit that computes local dimming information for local dimming control of the backlight based on the image data from the processing device and the global dimming information; and a light source control circuit that performs light source control of the backlight based on the local dimming information from the dimming control circuit.

[0006] Other aspects of this disclosure relate to a circuit arrangement comprising: an interface circuit that receives global dimming information from a processing device for global dimming control of a display device having a display panel and a backlight, the processing device calculating the global dimming information and performing color correction on image data based on the global dimming information; a dimming control circuit that calculates local dimming information for local dimming control of the backlight based on the image data and the global dimming information from the processing device; and a light source control circuit that performs light source control of the backlight based on the local dimming information from the dimming control circuit.

[0007] Other aspects of this disclosure relate to display systems that include the display control system and the display device described above. Attached Figure Description

[0008] Figure 1 This is an example of the structure of the display control system and circuit device in this embodiment.

[0009] Figure 2 This is a detailed structural example of the display control system and circuit device of this embodiment.

[0010] Figure 3 This is an example of the structure of a backlight and a display panel.

[0011] Figure 4 This is an explanatory diagram of the light source and display area.

[0012] Figure 5 This is a flowchart illustrating a detailed example of the processing described in this embodiment.

[0013] Figure 6 This is an explanatory diagram for color correction.

[0014] Figure 7 This is an explanatory diagram of dimming control.

[0015] Figure 8 These are other detailed structural examples of the circuit device in this embodiment.

[0016] Figure 9 These are other detailed structural examples of the circuit device in this embodiment.

[0017] Figure 10 This is an example of the structure of a head-up display, which is one example of the display system in this embodiment.

[0018] Label Explanation

[0019] 5: Display control system; 10: Circuit device; 20: Distortion correction circuit; 30: Color correction circuit; 40: Interface circuit; 50: Dimming control circuit; 52: Brightness analysis unit; 54: Brightness calculation unit; 56: Dimming amount calculation unit; 60: Light source control circuit; 70: Interface circuit; 100: Display device; 110: Display panel; 115: Diffuser plate; 120: Backlight; 130: Light source driver; 140: Display driver; 150: Reflector; 160: Transparent screen; 190: Head-up display; 200: Processing device; 210: Global dimming control unit; 220: Color correction unit; 250: External light sensor; AR, AR1~AR9: Area; B: Brightness; C: Color; DMG: Global dimming information; DML: Local dimming information; G: Brightness correction value; IM, IMI: Image data; IMD: Display image data; LS: Light source; σ: Diffusion coefficient value. Detailed Implementation

[0020] The preferred embodiments of this disclosure will now be described in detail. Furthermore, the embodiments described below are not intended to unduly limit the scope of the claims, and not all structures described in these embodiments are necessarily essential structural elements.

[0021] 1. Display control system and circuit device

[0022] Figure 1 This embodiment illustrates a structural example of the display control system 5 and circuit device 10. The display control system 5 includes a processing device 200 and a circuit device 10. The circuit device 10 includes a dimming control circuit 50 and a light source control circuit 60. The display control system 5 is a system that performs display control on the display device 100.

[0023] The display device 100 displays images based on image data. Taking a head-up display (HUD) as an example, the display device 100 is a device for displaying a virtual image in the user's field of vision. Alternatively, the display device 100 may be a display device for a HUD, but it could also be other automotive display devices such as a cluster display for an instrument panel, or a display device for purposes other than automotive use. Furthermore, the head-up display will be appropriately referred to as a HUD below.

[0024] The display device 100 includes a display panel 110 and a backlight 120. The display panel 110 is, for example, an electro-optical panel. Furthermore, the display device 100 may also include a light source driver (not shown) that drives the light source of the backlight 120, a display controller (not shown), and a display driver (not shown) that drives the display panel 110. For example, a plurality of light sources LS are provided in the backlight 120. Specifically, a plurality of light sources LS implemented by LEDs, etc., are arranged in an array in the backlight 120. The light source driver drives these plurality of light sources LS to emit light. The display driver may include a data driver that drives the data lines of the display panel 110, a scan driver that drives the scan lines of the display panel 110, etc.

[0025] The processing device 200 is, for example, a System-on-a-Chip (SoC), also known as a host device. The processing device 200 can be implemented, for example, by a microcomputer, CPU, or MPU. For example, the circuit device 10 is communicatively connected to the processing device 200 via an interface circuit (not shown). Furthermore, image data IMI from the processing device 200 is input to the circuit device 10 via the interface circuit.

[0026] The circuit device 10 is, for example, an integrated circuit device on a semiconductor substrate in which multiple circuit elements are integrated. The display device 100 displays an image based on display image data from the circuit device 10. In the case where the display device 100 is a HUD, the circuit device 10 is a HUD controller.

[0027] Furthermore, the processing device 200 calculates global dimming information for global dimming control of the backlight 120 of the display device 100. Additionally, the processing device 200 performs color correction on the image data based on the global dimming information. The calculation of the global dimming information is performed by the global dimming control unit 210, and the color correction of the image data is performed by the color correction unit 220. The global dimming control unit 210 and the color correction unit 220 can be implemented, for example, by a processor implementing the processing device 200, or a program running in the processor.

[0028] For example, the processing device 200 performs global dimming control processing for the backlight 120 based on detection information from external light sensors, etc. For instance, it performs global dimming control processing to brighten the light source LS of the backlight 120 when the external light is bright, and to dim the light source LS of the backlight 120 when the external light is dim. Furthermore, the processing device 200 calculates global dimming information DMG for such global dimming control. The global dimming information DMG is information on the dimming amount of the backlight 120 based on global dimming. For example, the global dimming information DMG is brightness correction information for the backlight 120 when global dimming is used to correct the brightness of the backlight 120. The processing device 200 outputs the calculated global dimming information DMG to the circuit device 10.

[0029] Furthermore, the processing unit 200 performs color correction on the image data and outputs color-corrected image data IMI. For example, the processing unit 200 performs color correction based on the global dimming information DMG calculated through global dimming, and outputs the color-corrected image data IMI to the circuit device 10. For example, when the brightness of the backlight 120 changes due to global dimming, the hue (color tone) of the displayed image on the display device 100 changes. For example, due to the color of the backlight 120, the hue of the displayed image also changes accordingly with the change in the brightness of the backlight 120. The processing unit 200 performs color correction to suppress the change in the hue of the displayed image in accordance with the change in the brightness of the backlight 120, and outputs color-corrected image data IMI.

[0030] The dimming control circuit 50 of the circuit device 10 calculates local dimming information for local dimming control of the backlight 120 based on image data IMI and global dimming information DMG from the processing device 200. For example, the dimming control circuit 50 receives the global dimming information DMG and the image data IMI that has been color-corrected based on the global dimming information DMG from the processing device 200, and calculates the local dimming information based on the image data IMI and the global dimming information DMG. The local dimming information is information on the dimming amount of the backlight 120 based on local dimming. For example, when the backlight 120 has multiple light sources, and each of the multiple light sources is set to correspond to each of the multiple areas of the display panel 110, the local dimming information is information on the dimming amount of each light source of the backlight 120 in each of the multiple areas. For example, the dimming control circuit 50 calculates the dimming amount of each light source of the backlight 120 in each area based on the analysis results of the image data IMI in each of the multiple areas and the brightness correction information as global dimming information DMG.

[0031] The light source control circuit 60 of the circuit device 10 performs light source control of the backlight 120 based on local dimming information from the dimming control circuit 50. For example, the light source control circuit 60 performs light source control to make the light source LS of the backlight 120 emit light at a dimming amount set by the local dimming information. For example, when the light source driver of the backlight 120 is provided in the display device 100, the light source control circuit 60 realizes the light source control of the backlight 120 by outputting brightness information of each area as local dimming information and control signals of the light source driver to the light source driver. When the light source control circuit 60 generates a PWM signal for the light source LS of the backlight 120, the light source control of the backlight 120 can also be realized by outputting the PWM signal.

[0032] Additionally, the circuit device 10 outputs display image data from the display device 100 to the display device 100. This display image data is image data that has undergone color correction based on local dimming information after color correction based on global brightness information (IMI). Furthermore, the dimming control circuit 50 and the light source control circuit 60 are, for example, logic circuits. These logic circuits can be configured as separate circuits, or they can be integrated into a single circuit through automatic configuration wiring, etc. Alternatively, some or all of these logic circuits can be implemented by a processor such as a DSP (Digital Signal Processor). In this case, a program and instruction set describing the functions of each circuit are stored in memory, and the processor executes the program and instruction set to implement the functions of each circuit.

[0033] As described above, in this embodiment, the processing device 200 calculates global dimming information for global dimming control. Furthermore, the processing device 200 performs color correction on the image data based on the global dimming information. Moreover, the dimming control circuit 50 of the circuitry 10 calculates local dimming information for local dimming control based on the image data and global dimming information from the processing device 200, and the light source control circuit 60 controls the backlight 120 based on the local dimming information. Thus, while the processing device 200 performs global dimming control, the circuitry 10 can implement a display control system 5 that reflects the global dimming control in its local dimming control. Therefore, even without changing the existing system of global dimming control, the processing device 200 can perform dimming control that considers local dimming control in its global dimming control, enabling more appropriate dimming control for the display device 100.

[0034] For example, the display control system 5 of this embodiment consists of a processing unit 200 that performs global dimming control and outputs an image to the circuit device 10, and a circuit device 10 that performs local dimming control on the input image. Furthermore, the circuit device 10, which is a HUD controller, uses the image and brightness correction information input from the processing unit 200 (which is the main device) as parameters to perform dimming control on each of the multiple regions. Therefore, without significantly modifying the existing system, it can coordinate with the global dimming control of the main device and display a high-contrast image.

[0035] For example, to date, the main device receives the brightness of external light via sensors, and outputs a signal to the light source driver to control the brightness of the backlight in order to improve the visibility of the display. Local dimming is achieved by dividing the backlight into zones and dimming each zone individually, resulting in a high-contrast image. To date, a combination of global dimming control and local dimming control of the main device has not been implemented in the HUD controller.

[0036] For example, when only global dimming control is performed, a single brightness control is applied to the entire screen. Therefore, in low-light environments, light leakage along the shape of the display from the backlight is visible to the naked eye. This degrades the visibility of the image displayed on the HUD and the driver's forward visibility. In the HUD's display control system, brightness information for global dimming control is traditionally input from the master device to the light source drivers. Therefore, in order to send control signals reflecting the brightness information of each area to each light source driver, the brightness information from the master device needs to be signal-processed and converted into signals for local dimming.

[0037] In this embodiment, the globally dimmed image and brightness correction information from the main device (processing unit 200) are used as parameters to perform local dimming control in the HUD controller (circuit unit 10), sending brightness information and driver control signals to each light source driver. This allows for backlight control of each area, enabling the display of a clear image with distinct brightness and darkness on the projection object, and suppressing light leakage in low-light environments. Furthermore, in cases where the image has locally dark areas, the backlight brightness can be dimmed only in those areas, thus reducing power consumption. Moreover, by simply assembling the HUD controller between the main device, the display, and the light source drivers, local dimming control coordinated with the main device's global dimming control can be achieved, allowing for functional expansion without major system modifications.

[0038] 2. Detailed structural example

[0039] Figure 2 This section shows a detailed structural example of the display control system 5 and circuit device 10 of this embodiment. Figure 2 In addition to the circuit device 10 Figure 1 In addition to the structure, it also includes distortion correction circuit 20, color correction circuit 30, and interface circuits 40 and 70. Furthermore, the circuit device 10, processing device 200, and display device 100 are not limited to... Figure 2 The structure of the example structure or other examples described below can be modified in various ways, such as omitting some of their structural elements, adding other structural elements, or replacing some structural elements with other structural elements.

[0040] The processing device 200 includes a global dimming control unit 210 and a color correction unit 220. The global dimming control unit 210 performs control processing for global dimming, and the color correction unit 220 corrects the color tone of the image. Specifically, the global dimming control unit 210 calculates global dimming information DMG for global dimming control of the backlight 120 of the display device 100 based on detection information from the external light sensor 250, and outputs the calculated global dimming information DMG to the circuit device 10. For example, if the global dimming control unit 210 determines that the external light detected by the external light sensor 250 is bright, it performs dimming processing to increase the brightness of the backlight 120; if it determines that the external light is dim, it performs dimming processing to decrease the brightness of the backlight 120. The color correction unit 220 performs color correction of the image data based on the calculated global dimming information DMG, and outputs the color-corrected image data IMI to the circuit device 10. For example, when the brightness correction of the backlight 120 is performed by the global dimming control unit 210 to brighten or darken the backlight 120, the color correction unit 220 performs color correction to suppress changes in the hue of the displayed image due to the brightness correction of the backlight 120. Additionally, the global dimming information DMG and image data IMI are output to the circuit device 10, for example, via an interface circuit (not shown).

[0041] The display device 100 includes a display panel 110, a backlight 120, and a light source driver 130. Alternatively, multiple light source drivers may be provided, with each light source driver configured for each light source group of the backlight 120. Furthermore, the display device 100 may include a display driver (not shown) that drives the display panel 110.

[0042] Figure 3 This is an example of the structure of the backlight 120 and the display panel 110. Figure 3 In the diagram, direction D1 is the horizontal scanning direction of the display panel 110, and direction D2 is the vertical scanning direction of the display panel 110. Direction D3 is orthogonal to directions D1 and D2, and is the direction from which the display panel 110 is viewed from above. The backlight 120 is located on the direction D3 side of the display panel 110, emitting illumination light in the opposite direction to the direction of the display panel 110, i.e., direction D3.

[0043] The backlight 120 includes multiple light sources LS. Figure 3The illustration shows an example of an 8×5 light source LS arranged in a 2D array. That is, 8 light source LSs are arranged along direction D1, and 5 light source LSs are arranged along direction D2. Furthermore, for appropriate local dimming, it is preferable to provide more than 100 light source LSs in the backlight 120, for example. The light source LS is, for example, an LED (Light Emitting Diode). However, the light source LS is not limited to LEDs; any light source that can independently control the light intensity and is close to a point light source is acceptable. A light source close to a point light source is one in which the size of the light-emitting portion of the light source LS is sufficiently smaller than the area AR corresponding to that light source LS. In addition, various configurations of the light source LS, such as square or hexagonal arrangements, can be considered.

[0044] The display panel 110 has a pixel array, and the area in this pixel array where the displayed image is shown is designated as the display area. The display area is divided into multiple regions AR. A light source LS is correspondingly arranged in each region AR. That is, one light source LS corresponds to one region AR. For example, when viewing the display panel 110 from above, the light source LS is positioned at the center of each region AR. However, the arrangement of the light sources LS is not limited to this. Figure 3 In this display panel 110, the display area is divided into 8×5 regions AR corresponding to the 8×5 light sources LS. Furthermore, the regions AR are used for processing in the circuit device 10, and the boundaries of the regions AR do not exist in the actual image displayed on the display panel 110. The display panel 110 is a panel whose transmittance is controlled according to the display image, and the display image is displayed by allowing each pixel to transmit illumination light from the backlight 120. The display panel 110 is, for example, a liquid crystal display panel.

[0045] Thus, when the display area of ​​the display panel 110 is divided into multiple regions, such that each region AR has a light source LS, the light source LS illuminating the display panel 110 has a light intensity distribution such that the light intensity decreases as one moves further away from the light source LS. Therefore, compared to the center of region AR, the light intensity decreases at the periphery. This light intensity distribution of the light source LS is called PSF. Figure 4 An example of the light intensity distribution of a PSF is shown. Figure 4 The light intensity distribution is represented by a gradient; the whiter the light, the larger the light intensity distribution coefficient. Figure 4 In this context, the size of the PSF corresponds to 3×3 regions AR1-AR9, with the center of the PSF positioned at the location of the light source.

[0046] like Figure 2As shown, the circuit device 10 includes a distortion correction circuit 20 and a color correction circuit 30. The distortion correction circuit 20 performs distortion correction on the input image data, i.e., image data IMI, from the processing device 200, and outputs distortion-corrected image data IM. Then, the color correction circuit 30 performs color correction on the image data IM from the distortion correction circuit 20.

[0047] Specifically, the distortion correction circuit 20 uses a coordinate transformation between the pixel coordinates in image data IMI and the pixel coordinates in image data IM to perform distortion correction on image data IMI, and outputs the result as image data IM. Distortion correction is an image correction for HUD displays that eliminates or reduces distortion by applying image distortion to the image that is opposite to the image distortion when the image displayed on the display panel 110 is projected. Image distortion caused by projection includes image distortion caused by the curvature of the screen in the HUD, image distortion caused by the HUD optical system, or both. For example, the HUD prompts the user with an image by projecting an image onto a transparent screen or by displaying an image on a transparent display panel. In this case, by deforming the image accordingly to the curvature of the transparent screen or transparent display panel, the user can see an undistorted image. The distortion correction circuit 20 performs such image deformation processing as distortion correction.

[0048] For example, the distortion correction circuit 20 performs either reverse mapping or forward mapping. Reverse mapping, also known as reverse warping, is a mapping process where the pixel coordinates in the image data IM (which serves as output image data) are transformed to their corresponding reference coordinates, and the pixel data of image data IM is calculated based on the pixel data of image data IMI in the reference coordinates. Forward mapping, also known as forward warping, is a mapping process where the pixel coordinates in image data IMI are transformed to their corresponding destination coordinates, and the pixel data of image data IM in the destination coordinates is calculated based on the pixel data of image data IMI in the pixel coordinates. The coordinate transformations in reverse and forward mapping are defined by mapping parameters, also known as mapping data. Mapping parameters can be tables that establish a correspondence between coordinates on the input image and coordinates on the output image, tables that represent the amount of movement between coordinates on the input image and coordinates on the output image, or coefficients of polynomials that establish a correspondence between coordinates on the input image and coordinates on the output image.

[0049] The color correction circuit 30 performs color correction on the image data IM and outputs the display image data IMD to the display device 100. That is, the color correction circuit 30 performs color correction on the image data IM and outputs the color-corrected image data IM as the display image data IMD to the display device 100. Color correction is, for example, color adjustment processing of the image data IM, which is a correction process that adjusts the color level. Color correction can also be referred to as brightness correction or grayscale correction of the image data IM.

[0050] For example, when dimming control is performed during the display of display image data IMD on display device 100, color correction circuit 30 performs color correction on image data IMD corresponding to the dimming amount in the dimming control. Dimming control is the control of adjusting the amount of light from light source devices such as backlights. Dimming control can be local dimming control that controls the brightness of light source devices such as backlights in each of multiple areas, or global dimming control that controls the overall brightness of the display screen. Moreover, in dimming control, in order to reduce the power consumption of light source devices and make black pixels appear darker, the amount of light from the light source devices is reduced. In this case, color correction circuit 30 performs color correction that increases the brightness of pixels corresponding to the light source in the display screen of display device 100 by reducing the amount of light from the light source. For example, color correction circuit 30 performs color correction on the pixel values ​​of image data IMD so that the image displayed on display device 100 based on display image data IMD has the same brightness and hue as the image of image data IMD, and outputs the color-corrected image data IMD to display device 100. Furthermore, the color correction performed by the color correction circuit 30 is not limited to color correction for compensating for dimming control, but can also be color correction for adjusting the hue of the displayed image on the display device 100, etc.

[0051] Interface circuit 40 is a circuit that performs interface processing with processing device 200, such as a host interface circuit. For example, global dimming information DMG calculated in processing device 200 is received from processing device 200 via interface circuit 40. Brightness correction information as received global dimming information DMG is stored in a register (not shown).

[0052] The interface circuit 70 is a circuit that performs interface processing with the display device 100. For example, brightness information, which is the local dimming information (DML) for each of the multiple regions, is output to the light source driver 130 of the display device 100 via the interface circuit 70. In addition, the interface circuit 70 also outputs control signals to the light source driver 130.

[0053] Alternatively, a processing device such as an MCU can be provided between the light source control circuit 60 and the light source driver 130 to accommodate differences in communication protocols depending on the model of the light source driver 130. In this case, the light source control circuit 60 controls the light source driver 130 via this processing device such as the MCU. Furthermore, the interface circuits 40 and 70 can also be implemented using a single interface circuit. Moreover, the distortion correction circuit 20, color correction circuit 30, dimming control circuit 50, light source control circuit 60, and interface circuits 40 and 70 are logic circuits. These logic circuits can be configured as separate circuits, or they can be integrated into a single circuit through automatic configuration wiring, etc. Alternatively, some or all of these logic circuits can be implemented using a processor such as a DSP. In this case, a program and instruction set describing the functions of each circuit are stored in memory, and the processor executes the program and instruction set to implement the functions of each circuit.

[0054] The dimming control circuit 50 performs dimming control of the light source based on image data IM. Specifically, the dimming control circuit 50 performs dimming control of the backlight 120, which has multiple light sources, to achieve dimming control, for example, a type of dimming control known as local dimming. For example, the dimming control circuit 50 performs calculation processing to obtain dimming amount information based on the image data IM. Here, the dimming amount information is used to specify the brightness of the light source to emit light through dimming control. The light source control circuit 60 performs control processing and instruction processing of the light source driver 130 of the display device 100 based on the dimming amount information from the dimming control circuit 50. Moreover, the light source driver 130, which is an LED driver, drives the light source LS of the backlight 120 based on the dimming amount information, thereby realizing dimming control of the backlight 120. For example, local dimming is achieved by implementing dimming control of each of the multiple areas obtained by dividing the display area of ​​the display panel 110.

[0055] Furthermore, in this embodiment, the dimming control circuit 50 performs brightness analysis on the image data IM, and calculates the local dimming information DML based on the results of the brightness analysis and the global dimming information DMG.

[0056] In this way, local dimming information DML corresponding to the brightness analysis result of image data IM is calculated, and backlight 120 is dimmed with a dimming amount corresponding to the local dimming information DML, thereby realizing local dimming control. Moreover, in this embodiment, in addition to the brightness analysis result of image data IM, local dimming information DML is also calculated based on global dimming information DMG from the processing device 200 that performs global dimming control. Therefore, for local dimming control performed in circuit device 10, dimming control of backlight 120 reflecting global dimming control of processing device 200 can be performed. As a result, even without changing the existing system such as global dimming control performed by processing device 200, local dimming control can be performed on the basis of global dimming control, and more appropriate dimming control of display device 100 can be achieved.

[0057] Specifically, in this embodiment, as in Figure 3 , Figure 4 As explained, the backlight 120 has multiple light sources LS, and each of the multiple light sources LS is provided corresponding to each of the multiple regions AR of the display panel 110. Furthermore, the dimming control circuit 50 performs brightness analysis on the image data IM in each region, and calculates the dimming amount of each light source corresponding to each region as local dimming information DML based on the brightness analysis results in each region and the global dimming information DMG.

[0058] In this way, the dimming amount, i.e. the brightness, of the light source LS corresponding to each of the multiple regions AR of the display panel 110 can be controlled based on the brightness analysis results of the image data IM in each region, thereby achieving local dimming control. Moreover, in this embodiment, in addition to the brightness analysis results of the image data IM in each region, local dimming information DML is calculated based on the global dimming information DMG from the processing device 200 that performs global dimming control. Therefore, for the local dimming control performed in the circuit device 10, dimming control of the backlight 120 that reflects the global dimming control of the processing device 200 can be performed, and more appropriate dimming control of the display device 100 can be achieved.

[0059] In addition, such as Figure 2As shown, the circuit device 10 includes a color correction circuit 30, which performs color correction on the image data IM based on image data IM and local dimming information DML. For example, the color correction circuit 30 performs color correction corresponding to the dimming control of the backlight 120 based on dimming amount information as local dimming information DML from the dimming control circuit 50. For example, if dimming control is performed in a region corresponding to the light source to reduce the light intensity of the light source, the color correction circuit 30 performs color correction to increase the brightness of the pixels in that region by reducing the light intensity of the light source in that region, and outputs the color-corrected display image data IMD to the display device 100. As a result, the light intensity of the light source in that region can be reduced, and an image corresponding to the original image data IM can be displayed in that region based on the color-corrected display image data IMD, thus achieving local dimming. As a result, it is possible to achieve low power consumption of the backlight 120, image display that makes black pixels appear darker, etc.

[0060] Furthermore, the circuit device 10 includes a distortion correction circuit 20 that corrects distortion in image data IMI from the processing device 200. Also, the color correction circuit 30 performs color correction based on the distortion-corrected image data IM and local dimming information DML.

[0061] By setting up such a distortion correction circuit 20, distortion correction can be performed on the image to correct for distortions caused by factors such as the curvature of the screen onto which the image displayed on the display panel 110 is projected. This allows the user to see an image without distortion. Furthermore, by performing color correction based on the distortion-corrected image data IM and the local dimming information DML, appropriate local dimming control based on the distortion-corrected image data IM can be achieved.

[0062] In addition, Figure 2 In this process, the processing unit 200 performs global dimming control based on the detection information from the external light sensor 250. For example, the external light sensor 250 detects the brightness of external light, and the global dimming control unit 210 of the processing unit 200 performs global dimming control and calculates global dimming information DMG based on the detection result of the brightness of external light.

[0063] In this way, global dimming control can be achieved, which adjusts the brightness of the backlight 120 according to the brightness of the external light. Furthermore, while the processing device 200 performs global dimming control using the detection information from the external light sensor 250, the circuit device 10 can perform local dimming control based on the analysis results of the image data IMI. Moreover, since the circuit device 10 performs local dimming control based on the analysis results of the image data IMI and the global dimming information DMG from the processing device 200, it is possible to achieve local dimming control that reflects the global dimming control using the external light sensor 250 within the processing device 200.

[0064] In addition, such as Figure 2 As shown, the display device 100 includes a light source driver 130 that drives the light source of the backlight 120. Furthermore, the light source control circuit 60 of the circuit device 10 outputs backlight dimming information based on local dimming information (DML) to the light source driver 130. For example, the light source control circuit 60 outputs brightness information in each region of the backlight 120 as the local dimming information (DML) as backlight dimming information, or outputs a PWM signal as backlight dimming information as described later.

[0065] In this way, the processing unit 200 performs global dimming control, outputting global dimming information DMG and image data IMI to the circuit unit 10. The circuit unit 10 then outputs backlight dimming information DML, calculated based on the image data IMI and the global dimming information DMG, to the light source driver 130. Thus, the processing unit 200 performs global dimming control, and the circuit unit 10 performs local dimming control, enabling the light source driver 130 to drive local dimming that reflects global dimming. Therefore, it is possible to achieve local dimming with minimal modification to existing systems.

[0066] 3. Dimming control

[0067] Next, the details of the dimming control circuit 50 will be explained. For example... Figure 2As shown, the dimming control circuit 50 includes a brightness analysis unit 52, a brightness calculation unit 54, and a dimming amount calculation unit 56. The brightness analysis unit 52 performs brightness analysis on the image data IM. The brightness calculation unit 54 performs brightness calculation based on the results of the brightness analysis in the brightness analysis unit 52 and the global dimming information DMG. The dimming amount calculation unit 56 performs local dimming information calculation based on the brightness calculation results in the brightness calculation unit 54. Specifically, the brightness analysis unit 52 searches for pixels with maximum brightness in each of the multiple regions of the display area based on the image data IM. The brightness calculation unit 54 corrects the maximum brightness of the searched pixels by multiplying it by the brightness correction value of the global dimming information DMG. Then, the dimming amount calculation unit 56 determines the brightness distribution of each light source in a way that allows displaying a color with the maximum brightness multiplied by the brightness correction value. Based on the determined brightness distribution of the light sources and the diffusion coefficient information of the light sources, it performs brightness calculation again for each pixel, calculating the dimming amount corresponding to the brightness value of the backlight 120 for each pixel. The diffusion coefficient information is, for example, described later. Figure 10 Information on the diffusion coefficient parameters of the diffuser plate 115. In addition, dimming information from the dimming amount calculation unit 56 is sent to the light source driver 130 via the light source control circuit 60. The light source driver 130 drives the light source of each region in the multiple regions to emit light in accordance with the dimming amount, thereby realizing local dimming.

[0068] Next, a specific processing example of this embodiment will be described. Figure 5 This is a flowchart illustrating a detailed processing example of this embodiment.

[0069] First, the processing device 200 performs global dimming control based on detection information from the external light sensor 250, calculating global dimming information DMG (step S1). Then, the processing device 200 performs color correction on the image data based on the global dimming information DMG (step S2). Next, the circuit device 10 receives the color-corrected image data IMI and the global dimming information DMG from the processing device 200 (step S3). By receiving the image data IMI and the global dimming information DMG, the circuit device 10 can execute local dimming control that reflects the global dimming control of the processing device 200.

[0070] Next, the dimming control circuit 50 performs brightness analysis on the image data IMI, searching for the pixel with the maximum brightness in each region of each light source (step S4). For example, in Figure 3 , Figure 4In each region corresponding to each light source, as described above, the brightness of pixels existing in that region is searched based on image data IM, and the pixel with the maximum brightness is found in that region. Then, the dimming control circuit 50 performs correction by multiplying the maximum brightness of the searched pixel by the brightness correction value of the global dimming information DMG (step S5). Then, the dimming control circuit 50 determines the brightness distribution of each light source in a way that allows the color of the pixel with the maximum brightness to be displayed (step S6). Here, the maximum brightness is the corrected maximum brightness obtained by multiplying the maximum brightness of the searched pixel by the brightness correction value, and is referred to as the maximum brightness below. For example, if the brightness range is 0-100, in the target region, the brightness of the pixel with the maximum brightness is set to 50. In this case, the brightness distribution of the light source is determined in a way that the pixel with the maximum brightness, i.e., 50, can be displayed with a color that is the upper limit of the brightness range, i.e., 100. If the brightness of the pixel with the maximum brightness is the upper limit of the brightness range, then the brightness of other pixels is ensured to fall within the brightness range of 0-100. Then, the dimming control circuit 50 recalculates the brightness of each pixel of the display panel 110 based on the diffusion coefficient information (step S7). Thus, the brightness value of the backlight 120 for each pixel is obtained.

[0071] For example, as described later Figure 10 As shown, in the display device 100, a diffuser plate 115 for diffusing light from the light source to achieve a uniform brightness distribution is disposed, for example, between the backlight 120 and the display panel 110. The diffuser plate 115 is also referred to as a diffuser sheet. For example, as... Figure 4 As shown, the light intensity distribution (PSF) of the light source decreases with distance from the light source. However, by using a diffuser plate 115 to diffuse the light from the light source, brightness unevenness can be reduced, achieving a uniform surface light source. Here, light diffusion methods include direct-lit, side-lit, and edge-lit methods. Furthermore, in... Figure 5 In step S7, besides Figure 4 In addition to the light intensity distribution PSF of the light source, it also reflects the diffusion of light from the light source by the diffuser plate 115. The brightness of each pixel on the display panel 110 is calculated again to obtain the brightness value of the backlight 120 for each pixel. As an example, for a pixel that becomes an object, the brightness is calculated based on... Figure 4 The intensity of light from a light source, such as 4×4 LEDs, surrounding the pixel is calculated using the light intensity distribution PSF and the diffusion coefficient information of the diffuser 115. The brightness is then calculated again to obtain the brightness value of the backlight 120 for each pixel. In this way, in a display device 100 including a backlight 120 with multiple light sources and a diffuser 115, the brightness value of the backlight 120 for each pixel can be appropriately determined.

[0072] Figure 6This is an explanatory diagram of a color correction processing example. First, as... Figure 5 As explained, the brightness B of the backlight 120 of the target pixel is determined. Furthermore, a table of brightness-coefficients is pre-stored in a storage circuit (not shown) of the circuit device 10, and the coefficient K is calculated based on the brightness B of the backlight 120 using this table. Figure 6 The luminance-coefficient table shows that the lower the luminance B, the larger the coefficient K. Alternatively, this luminance-coefficient table can be omitted, and the coefficient K can be calculated based on the luminance B using a prescribed formula. Furthermore, Figure 6 The brightness-coefficient table represents a first-order characteristic, but it is not limited to this; any characteristic appropriate to the human eye's perception of light intensity is acceptable. Alternatively, the coefficient K can be obtained by interpolating the two output values ​​of the brightness-coefficient table using first-order interpolation or spline interpolation. Then, the obtained coefficient K is multiplied by the color level C of the target pixel to determine the color level output to the display device 100. That is, for pixels with low brightness B in the backlight 120, the color level of the image data is increased. Thus, the color correction circuit 30 can determine the display image data IMD based on the image data IM and output it to the display device 100. Figure 6 In the brightness-coefficient table, the lower the brightness B of the backlight 120, the larger the coefficient K. Therefore, the lower the brightness of the backlight 120 of the object pixel, the higher the color level of the object pixel, which enables dimming control.

[0073] Figure 7 This is an explanatory diagram of the dimming control in this embodiment. The brightness analysis unit 52 takes the color C of the input target pixel as image data, performs brightness analysis on each region, searches for the pixel with the maximum brightness in each region, and outputs the maximum brightness B of each region. The brightness B is, for example, a value in the range of 0 to 255.

[0074] The brightness calculation unit 54 is input with the brightness B and the brightness correction information for global dimming, namely the brightness correction value G. The brightness correction value G is a value in the range of 0-1, where "0" corresponds to 0% and "1" corresponds to 100%. Then, the brightness calculation unit 54 multiplies the brightness B by the brightness correction value G and outputs B×G. By performing such multiplication, local dimming control that reflects global dimming control can be realized. The dimming amount calculation unit 56 is input with B×G and the diffusion coefficient value σ, which is diffusion coefficient information, and outputs B×G×σ. Then, the color correction circuit 30 is input with B×G×σ and the image data of color C, and outputs C×(255 / B×G×σ). Thus, Figure 6 The color correction is explained in the text. Additionally, if the calculated result of C×(255 / B×G×σ) exceeds 255, it is treated as 255.

[0075] Thus, in Figure 7 In the process, the pixel with the maximum brightness B is searched for in each region of the image data, and this brightness B is multiplied by the global dimming brightness correction value. Then, it is multiplied by the diffusion coefficient value σ. Based on the calculated B×G×σ, color correction C of the image data is performed, and C×(255 / B×G×σ) is output. This allows for appropriate color correction. Furthermore, by multiplying the maximum brightness B of each region by the global dimming brightness correction value G, the brightness of each light source in the backlight 120 is calculated, thus enabling local dimming control that reflects global dimming control.

[0076] 4. Other structural examples

[0077] Figure 8 , Figure 9 Other structural examples of the display control system 5 and circuit device 10 of this embodiment are shown. For example, in Figure 2 In the process, the light source control circuit 60 outputs the information used by the light source driver 130 to generate the PWM signal as backlight dimming information to the light source driver 130. Conversely, in... Figure 8 In this circuit, a circuit for generating a PWM signal is provided in the light source control circuit 60, and the PWM signal is output to the display device 100 through this circuit. This PWM signal is a signal that sets the pulse width based on brightness information, specifically dimming information of the light source 120. For example, the light source driver 130 buffers the PWM signal from the light source control circuit 60 to drive the LED or other light source of the backlight 120. Alternatively, the light source driver 130 may not be provided, and the light source control circuit 60 may directly drive the light source of the backlight 120.

[0078] In addition, Figure 2 In the process, the processing device 200 performs global dimming control based on the detection information from the external light sensor 250, but... Figure 9In this system, global dimming control is performed based on detection information regarding the on / off state of the headlights. Specifically, the processing unit 200 performs global dimming control based on the detection information regarding the on / off state of the headlights of a moving vehicle such as a car equipped with the display control system 5. For example, when the headlights are turned on or off depending on the ambient light level, the processing unit 200 performs global dimming control based on this detection information. For instance, when the headlights are turned on at night or when entering a tunnel, it can be determined that the ambient light level has darkened, so the processing unit 200 performs global dimming control, for example, by reducing the brightness of the backlight 120. On the other hand, when the headlights are turned off in the morning or during the day, or when exiting a tunnel, it can be determined that the ambient light level has brightened, so the processing unit 200 performs global dimming control, for example, by increasing the brightness of the backlight 120. Furthermore, the on / off state of the headlights can be automatically controlled by sensors, or it can be manually controlled by the driver of the vehicle.

[0079] 5. Display System

[0080] exist Figure 10 Here, as an example of the display system of this embodiment, a structural example of a head-up display 190 is shown. The head-up display 190, as the display system of this embodiment, includes the display control system 5 of this embodiment and the display device 100. Alternatively, the display control system 5 may also be a structure that does not include the processing device 200. The display device 100 displays a display image based on display image data IMD from the circuit device 10. In the case of the display system of the head-up display 190, the display device 100 displays a virtual image to the user by projecting the display image. For example, the display device 100 includes a display panel 110 and a backlight 120. Furthermore, the display device 100 may include a display driver 140 that drives the display panel 110, and a diffuser 115 disposed between the display panel 110 and the backlight 120. Additionally, the display device 100 may include a projection optical system such as a reflector 150 that reflects the projection light of the projected image.

[0081] The display driver 140 drives the data lines and scan lines of the display panel 110 to display an image based on the display image data (IMD) from the circuit device 10. Light emitted from the backlight 120 passes through the diffuser 115 and the display panel 110, and is reflected by the reflector 150 towards the transparent screen 160. The transparent screen 160 is, for example, a car windshield. The reflective surface of the transparent screen 160 is, for example, concave, so the projected image appears as a virtual image from the user's perspective. That is, from the user's viewpoint, the projected image appears to be formed at a position farther away than the transparent screen 160. Thus, the projected image can be displayed within the background.

[0082] Furthermore, the display system of this embodiment is not limited to... Figure 10The structure allows for various modifications. For example, the display panel 110 can be any display panel other than a liquid crystal display panel, and the configuration structure of the diffuser plate 115 and the projection optical system can also be modified in various ways. Furthermore, the display system of this embodiment is not limited to... Figure 10 Such a head-up display 190 can also be a cluster display or other display systems used in automobiles, or it can be a display system used outside of automobiles.

[0083] As explained above, the display control system of this embodiment includes: a processing device that provides global dimming information and performs color correction on image data based on the global dimming information, the global dimming information being used for global dimming control of the backlight of a display device having a display panel and a backlight; and a circuit device that performs display control of the display device based on image data from the processing device. Furthermore, the circuit device includes: a dimming control circuit that calculates local dimming information for local dimming control of the backlight based on the image data and the global dimming information from the processing device; and a light source control circuit that performs light source control of the backlight based on the local dimming information from the dimming control circuit.

[0084] In this embodiment, the processing device calculates global dimming information and performs color correction on image data based on the global dimming information. The dimming control circuit of the circuitry calculates local dimming information based on the image data and the global dimming information, and the light source control circuit performs backlight control based on the local dimming information. Thus, while the processing device performs global dimming control, the circuitry can perform local dimming control that reflects this global dimming control. Therefore, even without changing the processing device to perform existing systems like global dimming control, dimming control that considers local dimming control can be implemented, enabling appropriate dimming control for the display device.

[0085] Alternatively, in this embodiment, the dimming control circuit may perform brightness analysis on the image data and calculate local dimming information based on the results of the brightness analysis and the global dimming information.

[0086] In this way, the local dimming information corresponding to the brightness analysis results of the image data is used to dim the backlight with a dimming amount corresponding to the local dimming information, thereby realizing local dimming control that reflects the global dimming control in the processing device.

[0087] Alternatively, in this embodiment, the backlight may have multiple light sources, each of which is correspondingly positioned to correspond to a region of the display panel. Furthermore, the dimming control circuit may perform brightness analysis of the image data in each region, and based on the results of the brightness analysis in each region and global dimming information, calculate the dimming amount of each light source corresponding to each region as local dimming information.

[0088] In this way, the dimming amount of the light source corresponding to each area of ​​the display panel can be controlled based on the brightness analysis results of the image data in each area and the global dimming information, thus realizing local dimming control that reflects the global dimming control in the processing device.

[0089] In addition, in this embodiment, the circuit device may also include a color correction circuit, which performs color correction on the image data based on the image data and local dimming information.

[0090] In this way, color correction can be performed based on the local dimming information from the dimming control circuit, corresponding to the dimming control of the backlight.

[0091] In addition, in this embodiment, the circuit device may include a distortion correction circuit that performs distortion correction on image data from the processing device, and a color correction circuit that performs color correction based on the distortion-corrected image data and local dimming information.

[0092] In this way, distortion correction can be performed on the image, which is opposite to the image distortion caused by the projection object onto which the displayed image on the display panel is projected. Furthermore, by performing color correction based on the distortion-corrected image data and local dimming information, appropriate local dimming control based on the distortion-corrected image data can be achieved.

[0093] In addition, in this embodiment, the processing device may also perform global dimming control based on detection information from an external light sensor.

[0094] This enables global dimming control, allowing the backlight brightness to be adjusted based on the ambient light level.

[0095] In addition, in this embodiment, the processing device may also perform global dimming control based on the detection information of the headlights being turned on and off on the moving body equipped with a display control system.

[0096] Thus, for example, when the headlights are turned on or off according to the brightness of the surrounding environment, the processing device can perform global dimming control based on the detection information of the on / off state.

[0097] In addition, in this embodiment, the display device may include a light source driver that drives the backlight, and the light source control circuit of the circuit device outputs backlight dimming information based on local dimming information to the light source driver.

[0098] In this way, the processing device performs global dimming control and outputs global dimming information and image data to the circuit device. The circuit device can output backlight dimming information based on local dimming information calculated from image data and global dimming information to the light source driver.

[0099] Furthermore, the circuit arrangement of this embodiment includes an interface circuit that receives global dimming information from a processing device. This global dimming information is used for global dimming control of a display device having a display panel and a backlight. The processing device calculates the global dimming information and performs color correction on image data based on the global dimming information. Additionally, the circuit arrangement includes: a dimming control circuit that calculates local dimming information for local dimming control of the backlight based on the image data and the global dimming information from the processing device; and a light source control circuit that performs light source control of the backlight based on the local dimming information from the dimming control circuit.

[0100] In this way, the processing device performs global dimming control, and the circuitry can perform local dimming control that reflects this global dimming control. Therefore, even without changing the processing device to perform existing systems that perform global dimming control, dimming control that takes into account global dimming control can be performed, enabling appropriate dimming control of the display device.

[0101] Furthermore, the display system of this embodiment includes the display control system and display device described above.

[0102] Furthermore, while this embodiment has been described in detail above, those skilled in the art will readily understand that various modifications can be made without substantially departing from the new aspects and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, in the specification or drawings, a term described at least once with a broader or synonymous term can be replaced with that different term anywhere in the specification or drawings. Additionally, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. Furthermore, the structure and operation of display control systems, circuit devices, display devices, display systems, head-up displays, etc., are not limited to those described in this embodiment, and various modifications can be implemented.

Claims

1. A display control system, characterized in that, The display control system includes: A processing device that calculates global dimming information, performs color correction on image data based on the global dimming information, and outputs color-corrected image data, wherein the global dimming information is used for global dimming control of the backlight of a display device having a display panel and a backlight; and A circuit device that performs display control of the display device based on the image data from the processing device. The circuit device includes: A distortion correction circuit that performs distortion correction on the color-corrected image data from the processing device and outputs the distortion-corrected image data. A dimming control circuit, based on the distortion-corrected image data and the global dimming information, calculates local dimming information for local dimming control of the backlight; and A light source control circuit that controls the backlight source based on the local dimming information from the dimming control circuit.

2. The display control system according to claim 1, characterized in that, The dimming control circuit performs brightness analysis on the image data after distortion correction, and calculates the local dimming information based on the results of the brightness analysis and the global dimming information.

3. The display control system according to claim 2, characterized in that, The backlight has multiple light sources. Each of the plurality of light sources is configured corresponding to a region of the plurality of areas on the display panel. The dimming control circuit performs brightness analysis on the distortion-corrected image data in each region, and calculates the dimming amount of each light source corresponding to each region as the local dimming information based on the brightness analysis results in each region and the global dimming information.

4. The display control system according to any one of claims 1 to 3, characterized in that, The circuit device includes a color correction circuit, which performs color correction on the distortion-corrected image data based on the local dimming information.

5. The display control system according to any one of claims 1 to 3, characterized in that, The processing device performs the global dimming control based on detection information from an external light sensor.

6. The display control system according to any one of claims 1 to 3, characterized in that, The processing device performs the global dimming control based on the detection information of the headlights being turned on and off on the moving body equipped with a display control system.

7. The display control system according to any one of claims 1 to 3, characterized in that, The display device includes a light source driver that drives the light source of the backlight. The light source control circuit of the circuit device outputs backlight dimming information based on the local dimming information to the light source driver.

8. A circuit device, characterized in that, The circuit device includes: An interface circuit receives global dimming information from a processing device. The global dimming information is used for global dimming control of a display device having a display panel and a backlight. The processing device calculates the global dimming information, performs color correction on the image data based on the global dimming information, and outputs the color-corrected image data. A distortion correction circuit that performs distortion correction on the color-corrected image data from the processing device and outputs the distortion-corrected image data. A dimming control circuit, based on the distortion-corrected image data and the global dimming information, calculates local dimming information for local dimming control of the backlight; and A light source control circuit that controls the backlight source based on the local dimming information from the dimming control circuit.

9. A display system, characterized in that, The display system includes: The display control system according to any one of claims 1 to 3; and The display device.

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