Circuit device and display system

Abstract

To provide a circuit arrangement that can check if color correction is appropriately performed to improve reliability.SOLUTION: A circuit arrangement 10 includes: a color correction circuit 30 that performs color correction for image data IM to output display image data IMD to a display unit 100; a reverse color correction circuit 40 that performs reverse color correction for the display image data IMD to output post-reverse color correction image data IMR; and a comparison circuit 80 that compares the image data IM and the post-reverse color correction image data IMR with each other, and outputs a result of the comparison as error detection information on the display image data IMD.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a circuit device, a display system, and the like. [Background technology]

[0002] In a display device, color correction is performed on image data, and the color-corrected display image data is sometimes displayed. For example, Patent Document 1 discloses a display device for a vehicle that corrects image data to a color tone that cancels the change in color when the color of the backlight changes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-117071 Summary of the Invention [Problem to be solved by the invention]

[0004] However, up until now, no method has been proposed for checking whether appropriate color correction has been performed on image data. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to a circuit device including a color correction circuit that performs color correction on image data and outputs display image data to a display device, an inverse color correction circuit that performs inverse color correction on the display image data and outputs image data after the inverse color correction, and a comparison circuit that compares the image data with the image data after the inverse color correction and outputs the result of the comparison as error detection information for the display image data.

[0006] Another aspect of the present disclosure relates to a circuit device including: a distortion correction circuit that performs distortion correction on input image data and outputs image data; a color correction circuit that performs color correction on the image data and outputs display image data to a display device; an inverse color correction circuit that performs inverse color correction on the display image data and outputs inverse-color-corrected image data; an inverse distortion correction circuit that performs inverse distortion correction on the inverse-color-corrected image data and outputs inverse-distortion-corrected image data; and a comparison circuit that compares the input image data with the inverse-distortion-corrected image data and outputs the result of the comparison as error detection information for the display image data.

[0007] Another aspect of the present disclosure relates to a display system including the above-described circuit device and the display device. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows an example of the configuration of a circuit device according to an embodiment of the present invention. [Figure 2] 3 shows a detailed first configuration example of the circuit device of the present embodiment. [Figure 3] An example of the backlight and display panel configuration. [Figure 4] FIG. [Figure 5] 10 is a flowchart illustrating a process of calculating brightness for each pixel. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] 10 shows a detailed second configuration example of the circuit device of the present embodiment. [Figure 9] 10 shows a detailed third configuration example of the circuit device of the present embodiment. [Figure 10] 10 is a detailed fourth configuration example of the circuit device of the present embodiment. [Figure 11] 10 shows a detailed fifth configuration example of the circuit device of the present embodiment. [Figure 12] 1 shows an example of the configuration of a head-up display, which is an example of a display system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described in detail below. Note that the embodiments described below do not unduly limit the scope of the claims, and not all of the configurations described in the embodiments are necessarily essential components.

[0010] 1.Circuit device 1 shows an example of the configuration of a circuit device 10 according to this embodiment. The circuit device 10 includes a color correction circuit 30, an inverse color correction circuit 40, and a comparison circuit 80.

[0011] The circuit device 10 is, for example, an integrated circuit device in which a plurality of circuit elements are integrated on a semiconductor substrate. The display device 100 displays an image based on display image data IMD from the circuit device 10. Taking a head-up display as an example, the display device 100 is a device for displaying a virtual image in the user's field of vision. The display device 100 is composed of, for example, a display panel and a display driver. The display device 100 may also include a light source device such as a backlight. The display device 100 is, for example, a display device used in a head-up display, but may also be another display device for automobiles, such as a cluster display, which is a display on an instrument panel, or may be a display device for purposes other than automobiles.

[0012] 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 display image data IMD to the display device 100. The color correction is, for example, a color adjustment process for the image data IM, and is a correction process for adjusting the color level. The color correction can also be called a brightness correction or gradation correction for the image data IM.

[0013] For example, when dimming control is performed when display image data IMD is displayed on the display device 100, the color correction circuit 30 performs color correction on the image data IM according to the dimming amount in the dimming control. Dimming control is control for adjusting the light intensity of a light source device such as a backlight. Dimming control may be local dimming control, which controls the brightness of a light source device such as a backlight for each of multiple areas, or dimming control, which globally controls the brightness of the entire display screen. Dimming control involves reducing the light intensity of the light source of the light source device to reduce power consumption of the light source device or to make black pixels appear blacker. In this case, the color correction circuit 30 performs color correction to increase the luminance of pixels corresponding to the light source on the display screen of the display device 100 by the amount of the reduced light intensity of the light source. For example, the color correction circuit 30 performs color correction on each pixel value of the image data IM so that the image displayed on the display device 100 based on the display image data IMD has the same brightness and color as the image of the image data IM, and outputs the color-corrected image data IM to the display device 100 as display image data IMD. The color correction performed by the color correction circuit 30 is not limited to color correction for compensating for such dimming control, but may be color correction for adjusting the color tone of the image displayed on the display device 100, etc.

[0014] The inverse color correction circuit 40 performs inverse color correction. Specifically, the inverse color correction circuit 40 performs inverse color correction on the display image data IMD to output inverse color-corrected image data IMR. Inverse color correction is the inverse of the color correction performed by the color correction circuit 30, and is the inverse conversion of the conversion performed in the color correction. For example, the inverse color correction performed by the inverse color correction circuit 40 is color correction to return the color-corrected display image data IMD to the original image data IM. For example, if color correction is performed to increase the luminance of each pixel of the display image data IMD due to a decrease in the light intensity of the light source during dimming control, the inverse color correction circuit 40 performs inverse color correction to reduce the increased luminance and return it to the original luminance. Alternatively, the inverse color correction may be a correction to return the changed hue to the original hue when the hue is changed by color correction. The inverse color-corrected image data IMR output by the inverse color correction circuit 40 does not need to match the original image data IM perfectly, as long as they match within a predetermined error range. The error range may be, for example, a range such as rounding error. Furthermore, the resolution of the inverse color corrected image data IMR and the original image data IM do not have to match, and for example, the inverse color corrected image data IMR may be image data with a lower resolution.

[0015] The comparison circuit 80 compares the image data IM with the inverse color-corrected image data IMR. The comparison circuit 80 then outputs the comparison result as error detection information for the display image data IMD. The error detection information is information for detecting errors in the display image data IMD. For example, the comparison circuit 80 outputs an error detection signal or error detection data as the error detection information. For example, the comparison circuit 80 may output setting data to a register (not shown) as the error detection information. For example, the comparison circuit 80 determines the degree of match between the image data IM and the inverse color-corrected image data IMR by comparing the image data IM with the inverse color-corrected image data IMR. The degree of match can also be referred to as the degree of similarity. For example, if the comparison circuit 80 determines that the image data IM and the inverse color-corrected image data IMR do not match, it outputs an error detection signal. On the other hand, if the comparison circuit 80 determines that the image data IM and the inverse color-corrected image data IMR match within a given error range, it does not output error detection information. Specifically, the comparison circuit 80 calculates an index indicating the degree of match between the image data IM and the inverse color-corrected image data IMR. The comparison circuit 80 then determines whether the calculated index exceeds a given threshold, and if so, outputs error detection information such as an error detection signal or error detection data. On the other hand, if the index value indicating the degree of match is equal to or less than the given threshold, the comparison circuit 80 does not output error detection information.

[0016] As described above, the circuit device 10 of this embodiment performs color correction on the image data IM to output display image data IMD to the display device 100, and also performs inverse color correction on the display image data IMD to obtain inverse color-corrected image data IMR. The original image data IM is then compared with the inverse color-corrected image data IMR, and the comparison result is output as error detection information. In this manner, it becomes possible to check whether the color correction circuit 30 performed color correction appropriately using the error detection information from the comparison circuit 80. For example, if the color correction is color correction in response to dimming control, it becomes possible to properly confirm whether the dimming control in the display device 100 is being executed. This improves the reliability of the circuit device 10.

[0017] The color correction circuit 30, the inverse color correction circuit 40, and the comparison circuit 80 are logic circuits. These logic circuits may be configured as separate circuits, or may be configured as an integrated circuit using automatic placement and routing or the like. Alternatively, some or all of these logic circuits may be realized by a processor such as a DSP (Digital Signal Processor). In this case, a program or instruction set describing the function of each circuit is stored in memory, and the function of each circuit is realized by the processor executing the program or instruction set.

[0018] 2. First configuration example Fig. 2 shows a detailed first configuration example of the circuit device 10 of this embodiment. In addition to the configuration of Fig. 1, the circuit device 10 of Fig. 2 includes a distortion correction circuit 20, a dimming control circuit 50, and a light source control circuit 60. Note that the circuit device 10 is not limited to the configuration of the first configuration example of Fig. 2 or other configuration examples described later, and various modifications are possible, such as omitting some of the components, adding other components, or replacing some of the components with other components.

[0019] A processing device 200 is provided outside the circuit device 10. The processing device 200 is, for example, an SoC (System on Chip), and more specifically, a microcomputer, a CPU, or an MPU. For example, the circuit device 10 is communicatively connected to the processing device 200 via an interface circuit (not shown). Then, for example, input image data IMI from the processing device 200 is input to the circuit device 10 via the interface circuit.

[0020] The display device 100 includes a display panel 110, a backlight 120, and light source drivers 130-1 to 130-n, where n is an integer equal to or greater than 2. The display device 100 may also include a display driver (not shown) that drives the display panel 110. The display driver drives the display panel 110 based on display image data IMD from the circuit device 10, causing the display panel 110 to display a display image. The display driver may include a data driver that drives data lines of the display panel 110, a scan driver that drives scan lines of the display panel 110, a display controller, and the like. The backlight 120 is provided with a plurality of light sources LS. For example, the plurality of light sources LS are arranged in an array. The display device 100 is an automotive display device used, for example, in a head-up display, cluster display, or the like. Note that, hereinafter, a head-up display will be referred to as HUD where appropriate.

[0021] 3 shows an example of the configuration of the backlight 120 and the display panel 110. In FIG. 3, 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 a direction perpendicular to directions D1 and D2, and is the direction in which the display panel 110 is viewed in plan. The backlight 120 is provided on the direction D3 side of the display panel 110, and emits illumination light in the opposite direction to direction D3, which is the direction toward the display panel 110.

[0022] The backlight 120 includes multiple light sources LS. FIG. 3 illustrates an example in which 8×5 light sources LS are arranged in a two-dimensional array. That is, eight light sources LS are arranged along direction D1, and five light sources LS are arranged along direction D2. For proper local dimming, it is desirable to provide the backlight 120 with, for example, 100 or more light sources LS. The light sources LS are, for example, light-emitting diodes (LEDs). Note that the light sources LS are not limited to LEDs, and may be any light source whose light output is independently controlled and approximates a point light source. A light source approximates a point light source in that the size of the light-emitting portion of the light source LS is sufficiently smaller than the area AR corresponding to the light source LS. The light sources LS may be arranged in various configurations, such as a square arrangement or a hexagonal arrangement.

[0023] The display panel 110 has a pixel array, and the area of ​​the pixel array where a display image is displayed is referred to as the display area. The display area is divided into multiple areas AR. A light source LS is arranged corresponding to each area AR. That is, one light source LS corresponds to one area AR. For example, when the display panel 110 is viewed in a plan view, the light source LS is arranged at the center of the area AR. However, the arrangement position of the light source LS is not limited thereto. In FIG. 3 , the display area is divided into 8×5 areas AR corresponding to the 8×5 light sources LS. Note that the areas AR are used for processing in the circuit device 10, and the boundaries of the areas AR do not exist in the display image actually displayed on the display panel 110. The display panel 110 is a panel in which the transmittance of each pixel is controlled according to the display image, and each pixel transmits illumination light from the backlight 120 to display the display image. For example, the display panel 110 is a liquid crystal display panel.

[0024] In this way, when the display area of ​​the display panel 110 is divided into multiple areas AR, with each light source LS disposed in each area AR, the light source LS that illuminates the display panel 110 has a light intensity distribution in which the light intensity decreases the further away from the light source LS. Therefore, the light intensity is lower at the periphery of the area AR than at the center. This light intensity distribution of the light source LS is called a PSF. Figure 4 shows an example of the light intensity distribution of the PSF. In Figure 4, the light intensity distribution is shown using a gradation, with whiter colors indicating larger coefficients for the light intensity distribution. In Figure 4, the size of the PSF corresponds to 3 x 3 areas AR1 to AR9, and the center of the PSF is located at the position of the light source.

[0025] 2, the circuit device 10 includes a distortion correction circuit 20. The distortion correction circuit 20 performs distortion correction on input image data IMI and outputs image data IM. The color correction circuit 30 performs color correction on the image data IM from the distortion correction circuit 20. The input image data IMI is input from the processing device 200, for example, via an interface circuit (not shown).

[0026] Specifically, the distortion correction circuit 20 performs distortion correction on the input image data IMI using coordinate transformation between pixel coordinates in the input image data IMI and pixel coordinates in the image data IM, and outputs the result as image data IM. Distortion correction involves applying image distortion to the image displayed on the display panel 110 that is the opposite of the image distortion that occurs when the image is projected. This image correction is intended to create a HUD display with reduced or no distortion. Image distortion due to projection includes image distortion due to the curved surface of the HUD screen, image distortion due to the HUD optical system, or both. For example, a HUD presents an image to a user by projecting it onto a transparent screen or displaying it on a transparent display panel. By transforming the image to match the curvature of the transparent screen or transparent display panel, the user sees an image without distortion. The distortion correction circuit 20 performs this image transformation process as distortion correction.

[0027] For example, the distortion correction circuit 20 performs reverse mapping or forward mapping. Reverse mapping, also known as reverse warping, is a mapping process that transforms pixel coordinates in image data IM, which is output image data, into corresponding reference coordinates and then obtains pixel data of the image data IM from pixel data of the input image data IMI at those reference coordinates. Forward mapping, also known as forward warping, is a mapping process that transforms pixel coordinates in the input image data IMI into corresponding destination coordinates and then obtains pixel data of the image data IM at those destination coordinates from pixel data of the input image data IMI at those pixel coordinates. The coordinate transformations in reverse mapping and forward mapping are defined by mapping parameters, also known as map data. The mapping parameters are a table that associates coordinates on an input image with coordinates on an output image, a table that indicates the amount of movement between coordinates on the input image and coordinates on the output image, or polynomial coefficients that associate coordinates on the input image with coordinates on the output image.

[0028] The dimming control circuit 50 performs dimming control of the light source based on the image data IM. Specifically, the dimming control circuit 50 performs dimming control of the backlight 120, which has multiple light sources, thereby achieving dimming control known as local dimming. For example, the dimming control circuit 50 performs arithmetic processing to determine information on the dimming amount based on the image data IM. The dimming amount information here is information for specifying the brightness at which the light source is to be illuminated by dimming control. The light source control circuit 60 performs control processing and instruction processing for the light source drivers 130-1 to 130-n of the display device 100 based on the dimming amount information from the dimming control circuit 50. The light source drivers 130-1 to 130-n, which are LED drivers, then drive the light sources LS of the backlight 120 based on the dimming amount information, thereby achieving dimming control of the backlight 120. For example, local dimming is achieved, in which dimming control is performed on each of multiple areas obtained by dividing the display area of ​​the display panel 110.

[0029] A processing device such as an MCU may be provided between the light source control circuit 60 and the light source drivers 130-1 to 130-n to absorb differences in communication protocols depending on the model of the light source drivers 130-1 to 130-n. In this case, the light source control circuit 60 controls the light source drivers 130-1 to 130-n via the processing device such as an MCU.

[0030] The dimming control circuit 50 includes a luminance analysis circuit 52 and a dimming amount calculation circuit 54. The luminance analysis circuit 52 performs luminance analysis of the image data IM. The dimming amount calculation circuit 54 then calculates the dimming amount for each light source based on the results of the luminance analysis. Specifically, the luminance analysis circuit 52 searches for the pixel with the maximum luminance in each of the multiple areas of the display area based on the image data IM. The luminance analysis circuit 52 then determines the luminance distribution for each light source so that the color with the maximum luminance can be displayed. The dimming amount calculation circuit 54 then performs an arithmetic process to recalculate the luminance for each pixel based on the determined luminance distribution of the light source and diffusion coefficient information for the light source, and calculates the dimming amount corresponding to the luminance value of the backlight 120 for each pixel. The diffusion coefficient information is, for example, information on the diffusion coefficient parameter of the diffuser 115 shown in FIG. 12 (described later). Furthermore, information on the dimming amount from the dimming amount calculation circuit 54 is sent to the light source drivers 130-1 to 130-n via the light source control circuit 60, and the light source drivers 130-1 to 130-n drive the light sources of each of the multiple areas to emit light according to the dimming amount, thereby realizing local dimming.

[0031] Meanwhile, the color correction circuit 30 performs color correction in response to the dimming control performed by the dimming control circuit 50 and outputs the display image data IMD to the display device 100. For example, the display image data IMD is output to the display device 100 via an interface circuit (not shown). For example, the color correction circuit 30 performs color correction in response to the dimming control of the backlight 120 based on dimming level information from the dimming level calculation circuit 54. For example, when dimming control is performed to reduce the light intensity of the light source in an area corresponding to the light source, the color correction circuit 30 performs color correction to increase the luminance of the pixels in that area by the amount of the reduction in the light intensity of the light source in that area, and outputs the color-corrected display image data IMD to the display device 100. This reduces the light intensity of the light source in that area and enables an image corresponding to the original image data IM to be displayed in that area based on the color-corrected display image data IMD, thereby achieving local dimming. As a result, it is possible to reduce the power consumption of the backlight 120 and display an image in which black pixels appear blacker.

[0032] The inverse color correction circuit 40 then performs inverse color correction on the color-corrected display image data IMD, thereby outputting inverse color-corrected image data IMR. For example, the inverse color correction circuit 40 performs inverse color correction to return the color-corrected display image data IMD to the image data IM before color correction, based on the display image data IMD and the dimming amount information from the dimming amount calculation circuit 54. For example, if dimming control is performed to reduce the light amount of the light source in an area corresponding to the light source, and color correction is performed to increase the brightness of the pixels in that area, the inverse color correction circuit 40 performs inverse color correction to reduce the brightness of the pixels in that area to restore them to their original state, and outputs the inverse color-corrected image data IMR.

[0033] The comparison circuit 80 compares the original image data IM with the inverse color-corrected image data IMR from the inverse color correction circuit 40 and outputs the comparison result as an error detection signal ERR, which is error detection information for the display image data IMD. For example, if it is determined that the image data IM and the inverse color-corrected image data IMR match within a predetermined error range, the comparison circuit 80 deactivates the error detection signal ERR. If it is determined that the image data IM and the inverse color-corrected image data IMR mismatch beyond the predetermined error range, the comparison circuit 80 activates the error detection signal ERR. Specifically, the comparison circuit 80 calculates an index indicating the degree of match between the image data IM and the inverse color-corrected image data IMR. If the calculated index is equal to or less than a given threshold, the comparison circuit 80 deactivates the error detection signal ERR. If the index exceeds the threshold, the comparison circuit 80 activates the error detection signal ERR. When an error is detected and the error detection signal ERR becomes active, the circuit device 10 or the processing device 200 controls the display device 100 to stop supplying the display image data IMD and / or to turn off the backlight 120. This makes it possible to prevent an inappropriate image from being displayed on the display device 100 or inappropriate dimming control from being performed, for example, in the event of a malfunction in the color correction circuit 30 or the dimming control circuit 50 due to a failure or the like.

[0034] As described above, in this embodiment, when backlight control is performed on a display panel 110, such as an LCD panel, color correction, which is color adjustment that takes backlight adjustment amounts into account, is performed on the display image data IMD to maintain the same color of the displayed pixels even when the light intensity of the backlight 120 changes. Then, inverse color correction is performed on the display image data IMD, and the display image data IMD is compared with the inverse color-corrected image data IMR to check that the color adjustment amounts are correct. For example, in the past, backlight control, particularly local dimming, which independently controls the brightness of each display area, has been used primarily to improve contrast in home televisions. Therefore, it was not necessary to implement safety features required in automotive systems. For example, in the past, automotive systems did not perform backlight control and color correction that took backlight adjustment amounts into account, so there was no need to check the validity of color-corrected image data from a safety perspective.

[0035] In this regard, in this embodiment, in order to confirm that the image after color correction by local dimming and the adjustment amount of the light source such as an LED are correct, a method is adopted in which the original image is regenerated from the image after color correction, the adjusted light source luminance, and information on the diffusion coefficient of the light source, and the regenerated image is compared with the input image. This makes it possible to confirm that the dimming control of local dimming is being performed correctly. In other words, it is possible to confirm that the color correction amount and the light source adjustment amount match, that is, that the same color appears to the human eye.

[0036] The color correction circuit 30, the inverse color correction circuit 40, the comparison circuit 80, the distortion correction circuit 20, the dimming control circuit 50, and the light source control circuit 60 are logic circuits, and these logic circuits may be configured as separate circuits or may be configured as an integrated circuit using automatic placement and routing or the like. Alternatively, some or all of these logic circuits may be realized by a processor such as a DSP. The same applies to other configuration examples described below.

[0037] Next, a specific example of processing in this embodiment will be described. FIG. 5 is a flowchart illustrating an example of processing for calculating the luminance of each pixel. First, for each area of ​​each light source, a search is made for a pixel with the maximum luminance (step S1). For example, in each area corresponding to each light source described in FIGS. 3 and 4, the luminance of pixels in that area is searched for based on image data IM, and the pixel with the maximum luminance in that area is found. Then, a luminance distribution for each light source is determined so that the color of the pixel with the maximum luminance can be displayed (step S2). For example, assume that the luminance range is 0 to 100 and the luminance of the pixel with the maximum luminance in the target area is 50. In this case, the luminance distribution of the light source is determined so that the pixel with the maximum luminance of 50 can be displayed in a color with a luminance of 100, for example, which is the upper limit of the luminance range. If the luminance of the pixel with the maximum luminance is at the upper limit of the luminance range, the luminance of the other pixels is guaranteed to be within the luminance range of 0 to 100. Then, the luminance is recalculated for each pixel of the display panel 110 based on the diffusion coefficient information (step S3). This determines the brightness value of the backlight 120 for each pixel.

[0038] For example, as shown in FIG. 12 (described later), the display device 100 includes a diffuser 115 between the backlight 120 and the display panel 110 to diffuse light from the light source and achieve a uniform luminance distribution. The diffuser 115 is also called a diffusion sheet. For example, as shown in FIG. 4 (FIG. 4), the light intensity distribution PSF of the light source is such that the light intensity decreases with increasing distance from the light source. However, by providing the diffuser 115 to diffuse the light from the light source, luminance unevenness can be reduced, enabling the realization of a uniform surface light source. Examples of light diffusion methods include direct, sidelight, and edgelight. In step S3 of FIG. 5 (FIG. 5), the luminance of each pixel of the display panel 110 is recalculated, taking into account the light intensity distribution PSF of the light source in FIG. 4 as well as the diffusion of light from the light source by the diffuser 115, thereby obtaining the luminance value of the backlight 120 for each pixel. As an example, for a target pixel, the luminance is recalculated by determining the intensity of light from, for example, 4×4 LED light sources around the pixel based on the light intensity distribution PSF of Fig. 4 and the diffusion coefficient information of the diffuser 115, thereby determining the luminance value of the backlight 120 for each pixel. In this way, in the display device 100 having the backlight 120 with multiple light sources and the diffuser 115, it becomes possible to properly determine the luminance value of the backlight 120 for each pixel.

[0039] FIG. 6 is an explanatory diagram of an example of color correction processing. First, the luminance B of the backlight 120 of the target pixel is calculated as described in FIG. 5. A luminance-coefficient table is stored in a memory circuit (not shown) of the circuit device 10, and this table is used to calculate the coefficient K from the luminance B of the backlight 120. The luminance-coefficient table of FIG. 6 is configured so that the coefficient K increases as the luminance B decreases. Instead of using such a luminance-coefficient table, the coefficient K may be calculated from the luminance B based on a predetermined formula. Although the luminance-coefficient table of FIG. 6 has linear characteristics, this is not limiting and any appropriate characteristics may be used in accordance with the human eye's response to light brightness. The coefficient K may also be calculated by interpolating the two output values ​​of the luminance-coefficient table using linear interpolation, spline interpolation, or the like. The coefficient K thus calculated is then multiplied by the level of the color C of the target pixel to determine the color level to be output to the display device 100. That is, a process is performed to increase the color level of the image data for pixels with low luminance B of the backlight 120. In this way, the color correction circuit 30 can obtain display image data IMD from the image data IM and output it to the display device 100. In the brightness-coefficient table of Fig. 6, the coefficient K increases as the brightness B of the backlight 120 decreases, and therefore the color level of the target pixel increases as the brightness of the backlight 120 for the target pixel decreases, making it possible to achieve dimming control.

[0040] FIG. 7 is an explanatory diagram of an example of the inverse color correction process. First, a coefficient K is calculated based on the luminance B of the backlight 120 of the target pixel and a luminance-coefficient table. In the luminance-coefficient table of FIG. 6, the coefficient K increases as the luminance B of the backlight 120 decreases. However, in FIG. 7, the coefficient K decreases as the luminance B decreases, which is the opposite of FIG. 6. By using a table with such characteristics, it is possible to achieve the inverse color correction of the color correction of FIG. 6. The coefficient K thus calculated is then multiplied by the color CQ level of the output pixel to determine the color level of the original image. That is, while color correction involves increasing the color level of image data for pixels with a low luminance B of the backlight 120, inverse color correction involves decreasing the color level of image data for pixels with a low luminance B of the backlight 120. In this way, the inverse color correction circuit 40 can calculate inverse-color-corrected image data IMR corresponding to the original image data IM from the display image data IMD and output it to the comparison circuit 80. 7, the lower the luminance of the backlight 120, the lower the coefficient K, and therefore it is possible to perform inverse color correction, which is the inverse conversion of the color correction in Fig. 6, on the display image data IMD to obtain inverse-color-corrected image data IMR corresponding to the original image data IM. Then, the comparison circuit 80 compares the inverse-color-corrected image data IMR with the original image data IM, making it possible to detect whether or not a problem has occurred in the color correction of the color correction circuit 30 or in the dimming control of the dimming control circuit 50.

[0041] Note that instead of using a brightness-coefficient table such as that shown in Figure 7, the coefficient K may be calculated from the brightness B based on a predetermined formula. The coefficient K may also be calculated by interpolating the two output values ​​of the brightness-coefficient table using linear interpolation, spline interpolation, or the like. Although Figures 6 and 7 show separate tables for color correction and inverse color correction, the color level of the original image may also be calculated by using the color correction table in Figure 6 and dividing the color CQ of the output pixel by the coefficient K.

[0042] As described above, in this embodiment, the color correction circuit 30 performs color correction on the image data IM according to the luminance of the light source of the display device 100, which displays an image using the display image data IMD and the light source. The inverse color correction circuit 40 performs inverse color correction on the display image data IMD according to the luminance of the light source of the display device 100.

[0043] In this way, when dimming control is performed to control the luminance of the light source of the display device 100, color correction according to the luminance of the light source due to the dimming control is performed on the image data IM, and the color-corrected display image data IMD is output to the display device 100. Furthermore, by performing inverse color correction according to the luminance of the light source on the display image data IMD, it becomes possible to output the inverse-color-corrected image data IMR corresponding to the original image data IM to the comparison circuit 80. As a result, by comparing the original image data IM with the inverse-color-corrected image data IMR, it becomes possible to check whether the color correction and dimming control that controls the luminance of the light source have been performed correctly.

[0044] Specifically, as shown in Fig. 2, the display device 100 includes a display panel 110 and a backlight 120 having a plurality of light sources. As described with reference to Figs. 3 and 4, a plurality of light sources are provided corresponding to each of a plurality of areas of the display panel 110. The color correction circuit 30 performs color correction on the image data IM according to the luminance of each light source, and the inverse color correction circuit 40 performs inverse color correction on the display image data IMD according to the luminance of each light source.

[0045] In this way, when dimming control is performed to control the brightness of the multiple light sources of the backlight 120, color correction according to the brightness of each of the multiple light sources due to the dimming control is performed on each pixel illuminated by light from each light source in the image data IM, and color-corrected display image data IMD is output to the display device 100. Furthermore, by performing inverse color correction according to the brightness of each of the multiple light sources of the backlight 120 on each pixel illuminated by light from each light source in the display image data IMD, it becomes possible to output inverse color-corrected image data IMR corresponding to the original image data IM to the comparison circuit 80. As a result, by comparing the original image data IM with the inverse color-corrected image data IMR, it becomes possible to check whether color correction and dimming control of the backlight 120 have been performed correctly.

[0046] For example, the display device 100 displays an image by emitting light from the light source of the backlight 120 to the display panel 110 and driving the display panel 110 to display based on display image data IMD from the circuit device 10. Taking the head-up display 190 of Fig. 12 as an example, the image displayed on the display panel 110 is projected onto a transparent screen 160, which is the windshield, so that a virtual image corresponding to the displayed image is displayed to the user. In addition, the dimming control circuit 50 performs dimming control to control the brightness of the light source of the backlight 120 based on the image data IM.

[0047] Then, the color correction circuit 30 performs color correction according to the luminance of the light source of the backlight 120, as described in FIG. 6. For example, the color correction circuit 30 performs color correction to increase the color level of each pixel of the display image data IMD as the luminance of the light source decreases due to dimming control. That is, for pixels where the luminance of the light source has decreased due to dimming control, color correction is performed to increase the luminance of the pixel color. This achieves local dimming.

[0048] On the other hand, the inverse color correction circuit 40 performs inverse color correction according to the luminance of the light source of the backlight 120, as described in FIG. 7. For example, the inverse color correction circuit 40 performs inverse color correction such that the color level of each pixel of the inverse color-corrected image data IMR decreases as the luminance of the light source decreases due to dimming control. That is, for pixels whose color luminance has increased due to color correction, inverse color correction is performed to decrease the color luminance, thereby generating inverse color-corrected image data IMR that restores the original image data IM. As a result, by comparing the image data IM with the inverse color-corrected image data IMR using the comparison circuit 80, it becomes possible to check whether the color correction and dimming control have been performed correctly.

[0049] As shown in FIG. 2 , the circuit device 10 includes a luminance analysis circuit 52 that performs luminance analysis of the image data IM and a dimming amount calculation circuit 54 that calculates the dimming amount of each light source based on the results of the luminance analysis. The color correction circuit 30 performs color correction based on the dimming amount calculation result of the dimming amount calculation circuit 54, and the inverse color correction circuit 40 performs inverse color correction based on the dimming amount calculation result of the dimming amount calculation circuit 54. In this manner, the dimming amount of each of the multiple light sources of the backlight 120 is calculated based on the luminance analysis result of the image data IM, and dimming control of the backlight 120 is performed based on the calculated dimming amount. Color correction is performed based on the calculated dimming amount, and color correction is performed according to the dimming control of the backlight 120, allowing color-corrected display image data IMD to be output to the display device 100. In addition, inverse color correction is performed on the color-corrected display image data IMD according to the calculated dimming amount, generating inverse color-corrected image data IMR corresponding to the image data IM before color correction, which can be compared with the image data IM by the comparison circuit 80.

[0050] Furthermore, the dimming amount calculation circuit 54 calculates the dimming amount of each light source based on the diffusion coefficient information of the backlight 120 and the results of the luminance analysis. For example, when a diffuser 115 is provided for the backlight 120 as shown in Fig. 12 and the light from the light source of the backlight 120 is diffused, the dimming amount of each light source is calculated based on the diffusion coefficient information of the light from the light source by the diffuser 115 and the results of the luminance analysis of the image data IM. In this way, when the light from the light source of the backlight 120 is diffused to reduce uneven luminance, dimming control and color correction that reflect the diffusion of the light from the light source become possible.

[0051] The circuit device 10 of this embodiment also includes a distortion correction circuit 20 that performs distortion correction on input image data IMI and outputs image data IM. This makes it possible to perform color correction and dimming control based on the image data IM after distortion correction by the distortion correction circuit 20. Therefore, even in a display device 100 that requires distortion correction for image display, proper color correction and dimming control can be achieved. Specifically, for example, as shown in FIG. 12 , even if the transparent screen 160, which is the projection surface for the display image of the display device 100, is curved, distortion correction according to this curvature can be performed, allowing an undistorted image to be displayed to the user and proper color correction and dimming control to be achieved.

[0052] 3. Second configuration example FIG. 8 shows a detailed second configuration example of the circuit device 10 of this embodiment. In addition to the configuration of FIG. 2, the second configuration example includes an inverse distortion correction circuit 70 and line buffers 22, 72, and 82. For example, in FIG. 2, the comparison circuit 80 compares the distortion-corrected image data IM with the inverse color-corrected image data IMR. In contrast, in FIG. 8, the comparison circuit 80 compares the input image data IMI before distortion correction with the inverse-distortion-corrected image data IMRR obtained by inversely correcting the inverse color-corrected image data IMR, and outputs an error detection signal ERR if they do not match. The input image data IMI is image data input from, for example, a processing device 200 external to the circuit device 10.

[0053] For example, the distortion correction circuit 20 performs a mapping process, which maps an image to match the surface shape of the projection target, as the distortion correction process. This mapping process transforms the image so that the image projected onto the projection target does not appear distorted when viewed by the user. Meanwhile, the inverse distortion correction circuit 70 performs an inverse mapping process, which corresponds to the inverse transformation of the mapping process performed by the distortion correction circuit 20, as the inverse distortion correction process. This inverse mapping process transforms an image transformed to match the projection target back to the original image. The projection target is the object onto which the display image generated by the circuit device 10 is projected or displayed. In the case of an in-vehicle head-up display, the projection target is the automobile's windshield, etc. The mapping process is a process of coordinate transformation of pixel positions of the image based on mapping parameters, also known as map data. The mapping process can include pixel value interpolation as a process associated with the coordinate transformation. Mapping processes include forward mapping and reverse mapping. The mapping parameters are parameters that indicate coordinate transformation corresponding to the shape of the reflection surface of the projection target, and are table data, etc., that associate pixel positions in the image before the mapping process with those in the image after the mapping process. The mapping process performed by the distortion correction circuit 20 and the inverse mapping process performed by the inverse distortion correction circuit 70 can be realized using these mapping parameters. A line buffer 22 is provided upstream of the distortion correction circuit 20, and the distortion correction circuit 20 performs distortion correction using input image data IMI that has been temporarily stored and accumulated in the line buffer 22. A line buffer 72 is also provided upstream of the inverse distortion correction circuit 70, and the inverse distortion correction circuit 70 performs inverse distortion correction using inverse color-corrected image data IMR that has been temporarily stored and accumulated in the line buffer 72. Similarly, a line buffer 82 is also provided upstream of the comparison circuit 80. The line buffers 22, 72, and 82 temporarily store image data for, for example, a predetermined number of scanning lines.

[0054] As described above, the circuit device 10 of FIG. 8 includes a distortion correction circuit 20 that performs distortion correction on input image data IMI and outputs image data IM; a color correction circuit 30 that performs color correction on the image data IM and outputs display image data IMD to the display device 100; and an inverse color correction circuit 40 that performs inverse color correction on the display image data IMD and outputs inverse-color-corrected image data IMR. The circuit device 10 further includes an inverse distortion correction circuit 70 that performs inverse distortion correction on the inverse-color-corrected image data IMR and outputs inverse-distortion-corrected image data IMRR; and a comparison circuit 80 that compares the input image data IMI with the inverse-distortion-corrected image data IMRR and outputs the comparison result as error detection information for the display image data IMD. This configuration allows the comparison circuit 80 to detect not only whether the color correction in the color correction circuit 30 was performed properly, but also whether the distortion correction in the distortion correction circuit 20 was performed properly. It also allows detection of whether the dimming control in the dimming control circuit 50 was performed properly. This improves the reliability of the circuit device 10.

[0055] 4.Third configuration example FIG. 9 shows a detailed third example configuration of the circuit device 10 of this embodiment. In addition to the configuration of FIG. 8, in this third example configuration, a line buffer 32 is provided upstream of the color correction circuit 30. That is, the circuit device 10 of FIG. 9 includes a line buffer 32 that temporarily stores image data IM. For example, distortion-corrected image data IM from the distortion correction circuit 20 is temporarily stored and accumulated in the line buffer 32. The color correction circuit 30 then performs color correction on the image data IM temporarily stored in the line buffer 32. In this manner, the color correction circuit 30 can wait for the luminance analysis by the luminance analysis circuit 52 and the dimming amount calculation process by the dimming amount calculation circuit 54 to be completed before performing color correction on the image data IM temporarily stored in the line buffer 32 and outputting the display image data IMD to the display device 100.

[0056] That is, a certain amount of processing time is required to perform luminance analysis on the image data IM and to calculate the dimming amount based on the results of the luminance analysis. Therefore, if the display image data IMD corresponding to the dimming control is output from the color correction circuit 30 to the display device 100 before dimming control based on the dimming amount calculation result of the dimming amount calculation circuit 54 is performed, problems with the image display on the display device 100 will occur. In this case, it is possible to perform color correction, luminance analysis, and dimming amount calculation on the image data IM corresponding to the input image data IMI, and then output the display image data IMD with a delay of, for example, one frame. However, this approach may degrade the quality of the moving image display. Therefore, in FIG. 9, the line buffer 32 temporarily stores image data IM for a predetermined number of scan lines, such as several tens of lines, so that the luminance analysis circuit 52 and the dimming amount calculation circuit 54 complete the luminance analysis and dimming amount calculation within the processing time corresponding to that predetermined number of lines. The color correction circuit 30 then waits for this processing time, performs color correction on the image data IM stored in the line buffer 32, and outputs the color-corrected display image data IMD to the display device 100. In this way, after the luminance analysis and the calculation of the dimming amount are completed, the display image data IMD that has been color corrected based on the calculation result of the dimming amount can be output to the display device 100, and dimming control can be performed based on the calculation result of the dimming amount. Therefore, it becomes possible to display a display image based on the display image data IMD that has been appropriately color corrected, with appropriate dimming control.

[0057] 5. Fourth Configuration Example FIG. 10 shows a detailed fourth example configuration of the circuit device 10 of this embodiment. In this fourth example configuration, a distortion correction circuit 24 is further provided in addition to the configuration of FIG. 8. The distortion correction circuit 24 performs distortion correction on the input image data IMI and outputs the distortion-corrected image data to the luminance analysis circuit 52. In this way, by providing the distortion correction circuit 24, which performs distortion correction on the input image data IMI, separately from the distortion correction circuit 20, it becomes possible to output the display image data IMD to the display device 100 after the calculation of the dimming amount is completed, without providing the line buffer 32 as shown in FIG. 9. In other words, it becomes possible to realize a function similar to that of the line buffer 32 of FIG. 9.

[0058] Here, the image data output from the distortion correction circuit 24 is not output in any order, such as starting from the pixel in the upper left corner of the screen and scanning horizontally to the pixel in the lower right corner, but is output in random order. Meanwhile, the luminance analysis circuit 52 performs luminance analysis for each area of ​​each light source, as described in FIG. 5. Therefore, even if pixel data is output in random order from the distortion correction circuit 24, the luminance analysis circuit 52 can determine which of the multiple areas described in FIG. 3 the coordinates of that pixel data are located in and perform luminance analysis for each area. This allows the luminance analysis and dimming amount calculation to be completed quickly, and the display image data IMD can be output to the display device 100 after the dimming amount calculation is completed, even without the line buffer 32 of FIG. 9.

[0059] 6. Fifth Configuration Example FIG. 11 shows a detailed fifth example configuration of the circuit device 10 of this embodiment. In the fifth example configuration, the dimming amount calculation circuit 54 calculates the dimming amount based on detection information from an illuminance sensor 56 that detects external light. The inverse color correction circuit 40 performs inverse color correction based on the detection information from the illuminance sensor 56. This configuration makes it possible to perform dimming control using the dimming amount calculated based on the detection information from the illuminance sensor 56 regarding the brightness of the external light. When dimming control is performed that reflects the detection information from the illuminance sensor 56 and color correction is performed in accordance with this dimming control, the inverse color correction circuit 40 performs inverse color correction based on the detection information from the illuminance sensor 56, thereby making it possible to appropriately generate inverse-color-corrected image data that corresponds to the original image data IM.

[0060] For example, in an HUD, it is desirable to perform dimming control to dim the backlight 120 when it becomes night or when the vehicle enters a tunnel. On the other hand, it is desirable to perform dimming control to brighten the backlight 120 when it becomes daytime or when light, such as sunlight, becomes stronger. For this purpose, an illuminance sensor 56 is provided to detect the brightness of the environment, and the dimming amount calculation circuit 54 calculates the dimming amount based on the detection information from the illuminance sensor 56. This results in dimming control that reflects the detection information from the illuminance sensor 56, and the color correction circuit 30 performs color correction in accordance with this dimming control that reflects the detection information from the illuminance sensor 56. The inverse color correction circuit 40 then performs inverse color correction that reflects not only the dimming control of normal local dimming, but also the dimming control based on the detection information from the illuminance sensor 56. This restores inverse-color-corrected image data IMR corresponding to the original image data IM, and the comparison circuit 80 compares the image data IM with the inverse-color-corrected image data IMR and outputs error detection information if they do not match.

[0061] Although the first to fifth configuration examples of this embodiment have been described above, this embodiment is not limited to these, and various modifications are possible, such as a configuration that combines at least two of the first to fifth configuration examples.

[0062] 7. Display System FIG. 12 shows an example of the configuration of a head-up display 190 as an example of the display system of this embodiment. The head-up display 190, which is a display system of this embodiment, includes the circuit device 10 of this embodiment and a display device 100. 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 projects a display image to display a virtual image to the user. For example, the display device 100 includes a display panel 110 and a backlight 120. The display device 100 may also include a display driver 140 that drives the display panel 110 and a diffuser 115 provided between the display panel 110 and the backlight 120. The display device 100 may also include a projection optical system such as a mirror 150 that reflects projection light of the projected image.

[0063] The display driver 140 drives the data lines and scanning lines of the display panel 110 based on the display image data IMD from the circuit device 10 to display an image. Light emitted by the backlight 120 passes through the diffuser 115 and the display panel 110 and is reflected by the mirror 150 toward the transparent screen 160. The transparent screen 160 is, for example, the windshield of an automobile. The reflective surface of the transparent screen 160 is, for example, concave, so that the projected image appears as a virtual image when viewed by the user. In other words, when viewed by the user, the projected image appears to be formed farther away than the transparent screen 160. This allows the projected image to be displayed within a background.

[0064] The display system of this embodiment is not limited to the configuration shown in Fig. 12 and can be modified in various ways. For example, a display panel other than a liquid crystal display panel may be used as the display panel 110, and the arrangement of the diffuser 115 and the projection optical system can also be modified in various ways. Furthermore, the display system of this embodiment is not limited to the head-up display 190 shown in Fig. 12 and may be another display system for automobiles, such as a cluster display, or a display system for use in other than automobiles.

[0065] As described above, the circuit device of this embodiment includes a color correction circuit that performs color correction on image data and outputs display image data to a display device, an inverse color correction circuit that performs inverse color correction on display image data and outputs image data after inverse color correction, and a comparison circuit that compares image data with image data after inverse color correction and outputs the comparison result as error detection information for the display image data.

[0066] According to this embodiment, color correction is performed on the image data, and the color-corrected display image data is output to the display device. At the same time, the display image data is subjected to an inverse color correction, resulting in inverse color-corrected image data. The image data and the inverse color-corrected image data are then compared, and the comparison result is output as error detection information. This makes it possible to check whether the color correction circuit performed the color correction properly based on the error detection information from the comparison circuit, thereby improving the reliability of the circuit device.

[0067] In addition, in this embodiment, the color correction circuit performs color correction on the image data according to the luminance of the light source of the display device that displays an image using the display image data and the light source, and the inverse color correction circuit may perform inverse color correction on the display image data according to the luminance of the light source.

[0068] In this way, by comparing the image data with the image data after inverse color correction, it is possible to check whether color correction and dimming control for controlling the brightness of the light source have been performed correctly.

[0069] In this embodiment, the display device may include a display panel and a backlight having a plurality of light sources, each of which may be provided corresponding to a plurality of areas of the display panel. The color correction circuit may perform color correction on the image data according to the luminance of each light source, and the inverse color correction circuit may perform inverse color correction on the display image data according to the luminance of each light source.

[0070] In this way, by comparing the image data with the image data after inverse color correction, it is possible to check whether color correction and dimming control of each light source of the backlight have been performed correctly.

[0071] In addition, this embodiment may include a luminance analysis circuit that performs luminance analysis of image data, and a dimming amount calculation circuit that calculates the dimming amount of each light source based on the results of the luminance analysis.The color correction circuit may perform color correction based on the calculation results of the dimming amount, and the inverse color correction circuit may perform inverse color correction based on the calculation results of the dimming amount.

[0072] In this way, the dimming amount of each light source of the backlight is calculated based on the results of the luminance analysis of the image data, and dimming control of the backlight is performed based on the calculated dimming amount. Then, color correction is performed based on the calculated dimming amount, so that display image data that has been color corrected according to the dimming control can be output to the display device. Furthermore, inverse color correction is performed according to the calculated dimming amount, so that inverse color-corrected image data corresponding to the image data can be generated and compared with the image data.

[0073] In this embodiment, the dimming amount calculation circuit may calculate the dimming amount of each light source based on the diffusion coefficient information of the backlight and the result of the luminance analysis.

[0074] In this way, when the light from the light source of the backlight is diffused to reduce unevenness in brightness, it becomes possible to perform dimming control and color correction that reflects the diffusion of the light from the light source.

[0075] This embodiment may also include a distortion correction circuit that performs distortion correction on input image data and outputs the image data.

[0076] In this way, it becomes possible to perform color correction and dimming control based on the image data after distortion correction by the distortion correction circuit.

[0077] The circuit device of this embodiment also includes a distortion correction circuit that performs distortion correction on input image data and outputs the image data, a color correction circuit that performs color correction on the image data and outputs display image data to the display device, an inverse color correction circuit that performs inverse color correction on the display image data and outputs inverse-color-corrected image data, an inverse distortion correction circuit that performs inverse distortion correction on the inverse-color-corrected image data and outputs inverse-distortion-corrected image data, and a comparison circuit that compares the input image data with the inverse-distortion-corrected image data and outputs the comparison result as error detection information for the display image data.

[0078] In this way, the comparison circuit can detect not only whether color correction in the color correction circuit has been performed properly, but also whether distortion correction in the distortion correction circuit has been performed properly, thereby improving the reliability of the circuit device, etc.

[0079] In this embodiment, the display device may include a display panel and a backlight having a plurality of light sources, each of which is provided corresponding to a plurality of areas of the display panel, and the circuit device may include a luminance analysis circuit that performs luminance analysis of image data and a dimming amount calculation circuit that calculates a dimming amount for each light source based on the results of the luminance analysis.The color correction circuit may perform color correction based on the calculation result of the dimming amount, and the inverse color correction circuit may perform inverse color correction based on the calculation result of the dimming amount.

[0080] In this way, by comparing the image data with the image data after inverse color correction, it is possible to check whether color correction and dimming control of each light source of the backlight have been performed correctly.

[0081] In this embodiment, a line buffer for temporarily storing image data may be included, and the color correction circuit may perform color correction on the image data temporarily stored in the line buffer.

[0082] In this way, after the luminance analysis and the calculation of the dimming amount are completed, the display image data that has been color corrected based on the calculation result of the dimming amount can be output to the display device, making it possible to perform dimming control based on the calculation result of the dimming amount.

[0083] In this embodiment, the dimming amount calculation circuit may calculate the dimming amount based on detection information from an illuminance sensor that detects external light, and the inverse color correction circuit may perform inverse color correction based on the detection information.

[0084] This makes it possible to perform dimming control using the dimming amount calculated based on the detection information from the illuminance sensor. When dimming control is performed that reflects the detection information from the illuminance sensor and color correction is performed in accordance with this dimming control, inverse color correction is performed based on the detection information from the illuminance sensor, making it possible to appropriately generate inverse color-corrected image data corresponding to the image data.

[0085] The display system of this embodiment includes the circuit device described above and a display device.

[0086] Although the present embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader or equivalent meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of the present embodiment and modifications are also included within the scope of the present disclosure. Furthermore, the configurations and operations of the circuit device, display device, display system, head-up display, etc. are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0087] 10...circuit device, 20...distortion correction circuit, 22...line buffer, 24...distortion correction circuit, 30...color correction circuit, 32...line buffer, 40...inverse color correction circuit, 50...dimming control circuit, 52...luminance analysis circuit, 54...dimming amount calculation circuit, 56...illuminance sensor, 60...light source control circuit, 70...inverse distortion correction circuit, 72...line buffer, 80...comparison circuit, 82...line buffer, 100...display device, 110...display panel, 115...diffuser, 120...backlight, 140...display driver, 150...mirror, 160...transparent screen, 190...head-up display, 200...processing device, AR, AR1 to AR9...area, ERR...error detection signal, IM...image data, IMD...display image data, IMI...input image data, IMR...image data after inverse color correction, IMRR...image data after inverse distortion correction, LS...light source

Claims

1. a color correction circuit that performs color correction on the image data and outputs display image data to a display device; an inverse color correction circuit that performs inverse color correction of the color correction on the display image data and outputs inversely color-corrected image data; a comparison circuit that compares the image data with the inverse color corrected image data and outputs a result of the comparison as error detection information for the display image data; Including, The color correction circuit performing the color correction on the image data in accordance with the luminance of the light source of the display device that displays an image using the display image data and a light source; The inverse color correction circuit A circuit device that performs the reverse color correction according to the luminance of the light source on the display image data.

2. a color correction circuit that performs color correction on the image data and outputs display image data to a display device; an inverse color correction circuit that performs inverse color correction of the color correction on the display image data and outputs inversely color-corrected image data; a comparison circuit that compares the image data with the inverse color corrected image data and outputs a result of the comparison as error detection information for the display image data; Including, The display device includes a display panel and a backlight having a plurality of light sources; a light source of each of the plurality of light sources is provided corresponding to each of the plurality of areas of the display panel; The color correction circuit performing the color correction on the image data according to the luminance of each of the light sources; The inverse color correction circuit A circuit device that performs the reverse color correction according to the luminance of each of the light sources on the display image data.

3. 3. The circuit device according to claim 2, a luminance analysis circuit for performing luminance analysis on the image data; a dimming amount calculation circuit that calculates a dimming amount for each of the light sources based on the result of the luminance analysis; Including, The color correction circuit performing the color correction based on the calculation result of the light control amount; The inverse color correction circuit A circuit device that performs the reverse color correction based on the calculation result of the dimming amount.

4. 4. The circuit device according to claim 3, The light control amount calculation circuit A circuit device that calculates the dimming amount of each of the light sources based on diffusion coefficient information of the backlight and the result of the luminance analysis.

5. 5. The circuit device according to claim 1, A circuit device comprising: a distortion correction circuit that performs distortion correction on input image data and outputs the image data.

6. a distortion correction circuit that performs distortion correction on input image data and outputs the image data; a color correction circuit that performs color correction on the image data and outputs display image data to a display device; an inverse color correction circuit that performs inverse color correction of the color correction on the display image data and outputs inversely color-corrected image data; an inverse distortion correction circuit that performs inverse distortion correction on the inverse color corrected image data, thereby outputting inverse distortion corrected image data; a comparison circuit that compares the input image data with the inverse distortion corrected image data and outputs a result of the comparison as error detection information for the display image data; A circuit device comprising:

7. 7. The circuit device according to claim 6, The display device includes a display panel and a backlight having a plurality of light sources; a light source of each of the plurality of light sources is provided corresponding to each of the plurality of areas of the display panel; The circuit device a luminance analysis circuit for performing luminance analysis on the image data; a dimming amount calculation circuit that calculates a dimming amount for each of the light sources based on the result of the luminance analysis; Including, The color correction circuit performing the color correction based on the calculation result of the light control amount; The inverse color correction circuit A circuit device that performs the reverse color correction based on the calculation result of the dimming amount.

8. 8. The circuit device according to claim 7, a line buffer for temporarily storing the image data; The color correction circuit a circuit device for performing the color correction on the image data temporarily stored in the line buffer;

9. 9. A circuit arrangement according to claim 3, 4, 7 or 8, The light control amount calculation circuit Calculating the dimming amount based on detection information from an illuminance sensor that detects external light; The inverse color correction circuit A circuit device that performs the reverse color correction based on the detected information.

10. A circuit arrangement according to any one of claims 1 to 9; the display device; A display system comprising:

Images