Circuit device and display system

Abstract

A circuit device and a display system. The circuit device comprises a brightness analysis circuit, a dimming circuit and a region enhancement circuit. The luminance analysis circuit performs luminance analysis on image data of an input image and outputs luminance information. The dimming circuit determines light source luminance information indicating the luminance of light emitted by each of the plurality of light source elements on the basis of the luminance information. And the region enhancement circuit performs region enhancement processing on the dimming circuit. The region enhancement process is a process in which, when a first region of the input image is subjected to the region enhancement process, the light emission brightness of the light source element corresponding to the first region is higher than when the first region is not subjected to the region enhancement process.

Description

Technical Field

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

[0002] Patent document 1 discloses an image display device for improving the visibility of a specific image. The image display device includes a display control unit. The display control unit controls the light source in such a manner that the brightness of a light emitting area other than a first light emitting area corresponding to a first display area of ​​a liquid crystal panel is smaller than the brightness of the first light emitting area. In addition, the display control unit controls the liquid crystal panel in such a manner that the transmittance of pixels other than the pixels of the first display area in the liquid crystal panel is smaller than the transmittance of the pixels of the first display area and increases as the distance from the first display area increases.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-028102

[0004] In the above-mentioned Patent Document 1, the display control unit controls the brightness of the light source in the light emitting area other than the first light emitting area corresponding to the first display area of ​​the liquid crystal panel, regardless of the displayed image. Therefore, even if the displayed image changes in the area other than the first display area, the brightness of the corresponding light source does not change, and thus, the displayed image cannot be properly dimmed. Therefore, there is a problem of poor display quality in the area other than the first display area. Summary of the invention

[0005] One embodiment of the present disclosure relates to a circuit device that controls a display device including multiple light source elements and a display panel, the circuit device including: a brightness analysis circuit that performs brightness analysis on image data of an input image and outputs brightness information; a dimming circuit that determines light source brightness information representing the luminous brightness of each of the multiple light source elements based on the brightness information; and a regional enhancement circuit that performs the following regional enhancement processing on the dimming circuit: when the regional enhancement processing is performed on a first region of the input image, the luminous brightness of the light source element corresponding to the first region is increased compared to a case where the regional enhancement processing is not performed on the first region.

[0006] Furthermore, another aspect of the present disclosure relates to a display system including the above-mentioned circuit device and the display device.

[0007] Furthermore, another embodiment of the present disclosure relates to a display system, comprising: a display device, comprising a plurality of light source elements and a display panel; and a display controller, which controls the display device, wherein the display controller sets the light emitting brightness of the light source elements corresponding to a first area of ​​the display panel displaying a specified icon to high brightness, and performs local dimming control on the light emitting brightness of the light emitting elements corresponding to a second area of ​​the display panel not displaying the specified icon based on image data of an input image of the display controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a structural example of an electronic device.

[0009] Figure 2 This is a structural example of a circuit device.

[0010] Figure 3 This is a detailed configuration example of a brightness analysis circuit.

[0011] Figure 4 This is an example of an image displayed on a display panel and an area to be enhanced.

[0012] Figure 5 This is a diagram illustrating the relationship between the backlight source and the regional enhancement.

[0013] Figure 6 This is a first detailed structural example of a circuit device.

[0014] Figure 7 is an example of regional enhancement.

[0015] Figure 8 is an example of regional enhancement.

[0016] Fig. 9 This is a second detailed structural example of the circuit device.

[0017] Fig.10 is an example of regional enhancement.

[0018] Fig.11 is an example of regional enhancement.

[0019] Fig.12 is a flow chart of the processing performed by the dimming circuit.

[0020] Fig.13 is an example of an ambient light source element.

[0021] Fig.14 This is a flow chart of the illumination brightness calculation process performed by the color correction circuit.

[0022] Fig.15 This is the third detailed structural example of the circuit device.

[0023] Description of symbols

[0024] 22 object pixel; 100 circuit device; 120 color correction circuit; 130 brightness analysis circuit; 131 brightness extraction unit; 132 downsampling unit; 140 regional enhancement circuit; 150 dimming circuit; 160 regional enhancement dimming unit; 170 storage unit; 171 attenuation rate distribution information; 172 regional enhancement information; 172a coefficient information; 172b initial value information; 200 display device; 210 backlight source; 220 display panel; 221; 222 instrument; 224~229 icons; 230 display driver; 240 light source driver; 300 processing device; 400 display system; 500 electronic device; AR, AR1~AR5 areas; CF1~CF5 coefficients; DDIM light source brightness data; DIMG global dimming parameters; IMA, IMB image data; PL brightness information. DETAILED DESCRIPTION

[0025] Hereinafter, preferred embodiments of the present disclosure will be described in detail. The present embodiments described below do not unduly limit the contents described in the claims, and not all structures described in the present embodiments are necessarily essential structural elements.

[0026] 1. Electronic equipment, display systems and circuit devices

[0027] Figure 1 The electronic device 500 includes a processing device 300 and a display system 400. As an example, the electronic device 500 is a vehicle-mounted display device including an instrument panel, a central information display, a head-up display, or an electronic mirror, a television device, or an information processing device including a display.

[0028] The display system 400 includes a circuit device 100 and a display device 200. The circuit device 100 is, for example, an integrated circuit device in which a plurality of circuit elements are integrated on a semiconductor substrate. Figure 1 Although the circuit device 100 and the display device 200 are described as different components, the circuit device 100 may be included in the display device 200 .

[0029] The display device 200 includes a backlight source 210, a display panel 220, a display driver 230, and a light source driver 240. An example of the display device 200 is a display used in a television device or an information processing device. Alternatively, the display device 200 may be a head-mounted display including a projection device for projecting to the eyes, or a head-up display including a projection device for projecting to the screen. When the display device 200 is a head-up display, the display device 200 further includes an optical system for projecting light emitted from the backlight source 210 and passing through the display panel 220 onto the screen.

[0030] When looking down at the backlight source 210, light source elements are arranged two-dimensionally in the backlight source 210. The light source element is a light-emitting element that emits light by power supply, such as an inorganic light-emitting diode or an organic light-emitting diode. In local dimming control, the light amount of each light source element arranged two-dimensionally is controlled independently of each other. Alternatively, the backlight source 210 may also be divided into a plurality of areas. When looking down, a plurality of light source elements are arranged in each area. The light source elements arranged in the area are controlled to have the same light amount, and the light amount of each area is controlled independently of each other.

[0031] An example of a two-dimensional configuration of light source elements is a square configuration in which light source elements are configured at all intersections of multiple rows and multiple columns. However, the two-dimensional arrangement is not limited to a square arrangement. For example, the two-dimensional arrangement may also be a configuration called a diamond arrangement or a staggered arrangement. In this arrangement, light source elements are configured at the intersections of one side of an odd-numbered row and an even-numbered row and an odd-numbered column, and at the intersections of the other side of an odd-numbered row and an even-numbered row and an even-numbered column, and no light source elements are configured at other intersections.

[0032] The light source driver 240 receives the light source brightness data DDIM from the circuit device 100 and drives each light source element of the backlight source 210 according to the light source brightness data DDIM. The light source driver 240 is, for example, an integrated circuit device. In addition, a plurality of light source drivers may be provided, each of which is an independent integrated circuit device.

[0033] The display panel 220 is an electro-optical panel that transmits light from the backlight 210 and displays an image by controlling the transmittance thereof. For example, the display panel 220 is a liquid crystal display panel.

[0034] The display driver 230 receives the image data IMB and a timing control signal for controlling the display timing from the circuit device 100. The display driver 230 drives the display panel according to the received image data IMB and the timing control signal, so that the display panel 220 displays an image.

[0035] The processing device 300 sends the image data IMA to the circuit device 100. The processing device 300 is a processor such as a CPU, a GPU, a microcomputer, a DSP, an ASIC or an FPGA. CPU is the abbreviation of a central processing unit. GPU is the abbreviation of a graphics processing unit. DSP is the abbreviation of a digital signal processor. ASIC is the abbreviation of an application-specific integrated circuit. FPGA is the abbreviation of a field programmable gate array.

[0036] The circuit device 100 receives the image data IMA and performs local dimming control of the display device 200 according to the image data IMA. The circuit device 100 dims the light luminance of each light source element or each area of ​​the backlight source 210 according to the brightness of the image data IMA, and outputs the light source brightness information obtained by the dimming as the light source brightness data DDIM to the light source driver 240. In addition, the circuit device 100 performs color correction on the image data IMA according to the light source brightness information, and outputs the color-corrected image data IMB to the display driver 230.

[0037] In addition, the circuit device 100 has a built-in display controller function. That is, the circuit device 100 sends the image data IMB and the timing control signal for controlling the display timing to the display driver 230. In addition, the circuit device 100 may also perform image processing such as grayscale correction, white balance correction, or zooming in and out for the image data IMA or the image data IMB. In addition, the circuit device 100 may not have a built-in display controller function, but may provide a display controller as an integrated circuit device different from the circuit device 100. In this case, the display controller may also be included in the display device 200. In addition, the display controller and the display driver 230 may be respectively composed of different integrated circuit devices, or may be composed of an integrated integrated circuit device.

[0038] 2. Configuration example of circuit device

[0039] In the following, illustration and description of the display controller function built into the circuit device 100 are omitted, and dimming and color correction are illustrated and described.

[0040] Figure 2 The circuit device 100 includes a color correction circuit 120 , a brightness analysis circuit 130 , a local enhancement dimming unit 160 , and a storage unit 170 .

[0041] The storage unit 170 stores the attenuation rate distribution information 171 and the regional enhancement information 172. The storage unit 170 is a register or a memory. The memory is a volatile memory such as a RAM, or a non-volatile memory such as an OTP memory or an EEPROM. RAM is the abbreviation of random access memory. OTP is the abbreviation of one-time programmable. EEPROM is the abbreviation of electrically erasable programmable read-only memory.

[0042] The attenuation rate distribution information 171 indicates the attenuation rate distribution of the light reaching the display panel from the light source element. The attenuation rate distribution indicates the relationship between the distance from the light source element to the pixel and the attenuation rate of the light illuminating the pixel by the light source element. The attenuation rate distribution is also called the attenuation characteristic or the brightness distribution. The attenuation rate distribution information 171 is, for example, a lookup table or function indicating the attenuation rate distribution. In the case where the function is a polynomial, the attenuation rate distribution information 171 may also be the coefficients of each term of the polynomial.

[0043] The region enhancement information 172 is used for the region enhancement process described later. The region enhancement information 172 includes information specifying the region to be enhanced. In addition, the region enhancement information 172 may also include enhancement control information in each region. The enhancement control information is, for example, Figure 6 The coefficient information 172a described later or Fig. 9 Initial value information 172b described later.

[0044] The circuit device 100 receives image data IMA from the processing device 300 via an image interface (not shown). The image represented by the image data IMA is referred to as an input image. The image interface method may be various methods such as LVDS, parallel RGB method or display port. LVDS is an abbreviation for low voltage differential signaling.

[0045] The received image data IMA is input to the brightness analysis circuit 130. The brightness analysis circuit 130 analyzes the brightness of the image data IMA and outputs the result as brightness information INT. The brightness information indicates the brightness of the image at each position of the input image. Figure 3 The detailed configuration example of the brightness analysis circuit is shown in FIG. 130 . The brightness analysis circuit 130 includes a brightness extraction unit 131 and a down-sampling unit 132 .

[0046] The input image is an RGB color image. That is, each pixel of the image data IMA has an R pixel value, a G pixel value, and a B pixel value. The brightness analysis circuit 130 uses the maximum value among the R pixel value, the G pixel value, and the B pixel value as the brightness value of the pixel. Thus, a first brightness image is obtained in which each pixel has a brightness value.

[0047] The downsampling unit 132 obtains a second brightness image by downsampling the first brightness image. The number of pixels of the second brightness image is less than the number of pixels of the first brightness image. Downsampling is performed in at least one of the horizontal scanning direction and the vertical scanning direction. As an example, the number of pixels is downsampled to less than 1 / 2 in both the horizontal scanning direction and the vertical scanning direction. The downsampling unit 132 outputs the second brightness image as brightness information INT.

[0048] The configuration of the brightness analysis circuit 130 is not limited to the above configuration. For example, the down-sampling unit 132 may be omitted and the first brightness image may be output as the brightness information INT.

[0049] The regional enhancement dimming unit 160 performs dimming of the backlight source 210 in the local dimming control and enhances the light quantity of the light source element corresponding to a specific area of ​​the input image. The regional enhancement dimming unit 160 includes a regional enhancement circuit 140 and a dimming circuit 150 .

[0050] The dimming circuit 150 generates light source brightness information indicating the light emitting brightness of each light emitting element based on the brightness information INT, and outputs the light source brightness information as light source brightness data DDIM. Specifically, the dimming circuit 150 uses the brightness information INT and the attenuation rate distribution information 171 stored in the storage unit 170 to perform dimming processing, thereby determining the light emitting brightness of each light source element. Details of this method will be described later. Alternatively, the dimming circuit 150 determines the maximum brightness of the pixels belonging to the image area corresponding to the light emitting element of the backlight source 210 based on the brightness information INT. The dimming circuit 150 determines the maximum light emitting brightness within the range that the display device 200 can display, and sets the light emitting brightness to the light emitting brightness of the light emitting element.

[0051] The regional enhancement circuit 140 performs regional enhancement processing on the dimming circuit 150 based on the regional enhancement information 172 stored in the storage unit 170. Local dimming control is performed on each light source element of the backlight source 210 through the dimming circuit 150. At this time, the regional enhancement circuit 140 performs regional enhancement processing in a manner that makes the light emission brightness of the light source element corresponding to the specific area higher than the light emission brightness when the regional enhancement processing is not performed. The regional enhancement processing is implemented by controlling the input to the dimming circuit 150 or controlling the dimming processing in the dimming circuit 150. The light emission brightness of the light emitting element corresponding to the area other than the specific area is determined by dimming based on the usual local dimming control. Figure 6 to Figure 8 as well as Figures 9 to 11 A detailed example of region enhancement processing is described in .

[0052] The color correction circuit 120 calculates the illumination brightness information based on the light source brightness data DDIM and the attenuation rate distribution information 171 stored in the storage unit 170. The illumination brightness information shows the illumination brightness in each pixel of the display panel 220 when the display panel 220 is illuminated by the backlight source 210. The calculation of the illumination brightness is described in detail in Fig.14The color correction circuit 120 performs color correction on the image data IMA according to the illumination brightness information and outputs the corrected image data IMB. Specifically, the color correction circuit 120 multiplies the pixel data of each pixel by the inverse of the brightness of the light reaching the pixel and uses the result as the new pixel data of the pixel. In addition, the image represented by the image data IMB is called an output image.

[0053] The circuit device 100 transmits the image data IMB of the output image to the display driver 230 via an image interface (not shown). The image interface may be of various types such as LVDS, parallel RGB, or display port.

[0054] In addition, the color correction circuit 120, the brightness analysis circuit 130, the regional enhancement circuit 140, and the dimming circuit 150 are logic circuits for processing digital signals. The color correction circuit 120, the brightness analysis circuit 130, the regional enhancement circuit 140, and the dimming circuit 150 can be respectively composed of logic circuits, or part or all of them can be composed of an integrated logic circuit. Alternatively, the functions of the color correction circuit 120, the brightness analysis circuit 130, the regional enhancement circuit 140, and the dimming circuit 150 can be realized by executing an instruction set or program that describes the functions of the color correction circuit 120, the brightness analysis circuit 130, the regional enhancement circuit 140, and the dimming circuit 150 through a processor such as a DSP.

[0055] Alternatively, the circuit device 100 may be a processor such as a CPU, GPU, microcomputer, DSP, ASIC, or FPGA. Furthermore, the processor may implement the functions of the circuit device 100 by executing an instruction set or program describing the functions of each part of the circuit device 100 .

[0056] Figure 4 2 is an example of an image displayed on a display panel and an area to be enhanced. Here, an example in which the display device 200 is a cluster panel (cluster panel) on a vehicle is shown.

[0057] An image including instruments 221, 222 and icons 224 to 229 of warning lights is displayed on the display panel 220. As an example, the background is black, but not limited to this. The area AR that becomes the area enhancement object is the area surrounding the icons 224 to 229. In addition, the area can also be set separately for each icon. In addition, the area AR can also be an area surrounding only a part of the icons 224 to 229.

[0058] Figure 51 is a diagram illustrating the relationship between the backlight source and the regional enhancement. The backlight source 210 includes a plurality of light source elements LG arranged two-dimensionally when viewed from above. The light emission brightness of the light source elements corresponding to the region AR among the plurality of light source elements LG is enhanced. The light source elements corresponding to the region AR are light source elements arranged to overlap with the region AR on the display panel 220 when the display panel 220 and the backlight source 210 are viewed from above. For example, the correspondence between the coordinates of the pixels in the image and the positions of the light source elements is stored in the storage unit 170. Based on the correspondence information and the information of the designated region AR, the light source element to be enhanced is determined.

[0059] In the present embodiment, the circuit device 100 controls the display device 200 including a plurality of light source elements LG and a display panel 220. The circuit device 100 includes a brightness analysis circuit 130, a dimming circuit 150, and a regional enhancement circuit 140. The brightness analysis circuit 130 performs brightness analysis on the image data IMA of the input image to output brightness information INT. The dimming circuit 150 determines light source brightness information representing the luminous brightness of each light source element of the plurality of light source elements LG based on the brightness information INT. The regional enhancement circuit 140 performs regional enhancement processing on the dimming circuit 150. The regional enhancement processing is a processing as follows: when the regional enhancement processing is performed on the first region of the input image, the luminous brightness of the light source element LG corresponding to the first region is increased compared to the case where the regional enhancement processing is not performed on the first region.

[0060] According to this embodiment, the light source element corresponding to the first area is processed by the regional enhancement process, and the light emission brightness becomes higher, so the image of the first area is displayed brightly. As a result, the visibility of the image of the first area is improved even in a bright environment. In addition, the light emission brightness of the light source element corresponding to the area where the regional enhancement process is not performed is determined by the dimming circuit 150 based on the brightness information INT of the image data IMA. As a result, the display image is appropriately dimmed, so the display quality of the image in the area where the regional enhancement process is not performed is good.

[0061] In addition, Region 1 and Figure 4 as well as Figure 5 Alternatively, the first area corresponds to the AR described later. Figure 7 AR1 to AR4 or the following Fig.10 Corresponding to any one of AR1 and AR2.

[0062] In addition, in the present embodiment, when determining that a predetermined icon is to be displayed in the first region, the region enhancement circuit 140 may perform region enhancement processing on the first region.

[0063] For example, the processing device 300 may send information on turning on / off the icon display to the circuit device 100, and the region enhancement circuit 140 may determine whether a predetermined icon is displayed in the first region based on the information on / off. Alternatively, the region enhancement circuit 140 may determine whether an icon is displayed in the first region based on the image data IMA or the brightness information INT of the first region.

[0064] According to this embodiment, when an icon is displayed in the first area, the visibility of the icon is improved by regional enhancement. On the other hand, when no icon is displayed in the first area, regional enhancement is not performed, so the light emission brightness of the light source element corresponding to the first area is suppressed, for example, the generation of a halo is suppressed. A halo is a phenomenon in which the peripheral portion of an icon or text, etc., appears blurred due to light leakage from the peripheral portion of the icon or text, etc.

[0065] In addition, in the present embodiment, the area enhancement circuit 140 may not perform the area enhancement process on the first area when the first area is displayed in black.

[0066] For example, the area enhancement circuit 140 determines whether the first area is displayed in black by determining whether the image data IMA or the brightness information INT of the first area is completely black.

[0067] According to the present embodiment, when the first region is not displayed in black, the region enhancement circuit 140 determines that a predetermined icon is displayed in the first region, and can perform region enhancement processing on the first region. On the other hand, when the first region is displayed in black, the region enhancement circuit 140 determines that a predetermined icon is not displayed in the first region, and does not perform region enhancement processing on the first region.

[0068] In addition, in the present embodiment, the display system 400 includes: a display device 200 including a plurality of light source elements LG and a display panel 220; and a display controller that controls the display device 200. The display controller sets the light emission brightness of the light source element LG corresponding to the first area of ​​the display panel 220 where the prescribed icon is displayed to high brightness. The display controller performs local dimming control on the light emission brightness of the light emitting element corresponding to the second area of ​​the display panel 220 where the prescribed icon is not displayed, based on the image data IMA of the input image of the display controller. In addition, the display controller here corresponds to the circuit device 100 of the present embodiment.

[0069] According to this embodiment, the light source element corresponding to the first area where the prescribed icon is displayed is set to high brightness, so the prescribed icon in the first area is displayed brightly. As a result, the visibility of the image in the first area is improved even in a bright environment. In addition, the light emitting brightness of the light source element corresponding to the second area where the prescribed icon is not displayed is locally dimmed based on the image data IMA. As a result, the displayed image is appropriately dimmed, so the display quality of the image in the second area where the prescribed icon is not displayed is good.

[0070] In addition, in this embodiment, the high brightness may also be a fixed brightness value that does not depend on the image data IMA. Fig.11 The regulations described later enhance the brightness value.

[0071] According to this embodiment, the light emission brightness of the light source element corresponding to the first area displaying the predetermined icon becomes a fixed brightness value independent of the image data IMA. Thus, the light source element corresponding to the first area displaying the predetermined icon can be set to high brightness without being affected by the local dimming control.

[0072] 3. Detailed Configuration Example 1

[0073] Figure 6 This is the first detailed structural example of the circuit device. Figure 2 The same components will be described in detail as appropriate. Figure 7 and Figure 8 The example of region enhancement shown here is used to explain the operation of each unit. However, the number of regions to be enhanced may be one or more.

[0074] like Figure 7 As shown, the first area AR1 to the fifth area AR5 are set for the input image based on the image data IMA. The first area AR1 to the fourth area AR4 are rectangular areas that do not overlap each other. The fifth area AR5 is an area other than the first area AR1 to the fourth area AR4 in the input image of one frame.

[0075] The brightness analysis circuit 130 outputs the brightness information INT that has been downsampled as described above. The first area AR1 to the fifth area AR5 in the brightness information INT are determined by the ratio of the number of pixels of the input image and the brightness information INT. In addition, an example of specifying the area using the coordinates on the input image is shown here, but the area can also be specified from the beginning using the coordinates on the brightness information INT.

[0076] The storage unit 170 stores the coefficient information 172a as the region enhancement information 172. Figure 8As shown, the coefficient information 172a is a first coefficient CF1 to a fifth coefficient CF5 set for each of the first area AR1 to the fifth area AR5. Each coefficient is greater than or equal to 0 and less than or equal to 1. Figure 8 An example of a coefficient is shown. For example, a coefficient greater than 0.5 is set for an area where the luminous brightness is to be enhanced. Conversely, a coefficient less than 0.5 is set for an area where the luminous brightness is to be reduced. The reference coefficient is not limited to 0.5.

[0077] The regional enhancement circuit 140 multiplies the brightness information INT of each region by a coefficient based on the coefficient information 172a, and outputs the result as the enhanced brightness information BPL. Specifically, the coordinates of the pixel in the brightness information INT are set to (u, v), and the brightness value of the pixel is set to INTin(u, v). u is the coordinate in the horizontal scanning direction, and v is the coordinate in the vertical scanning direction. Let p be an integer greater than 1 and less than 5, and (u, v) belongs to the pth region ARp. At this time, the regional enhancement circuit 140 calculates the brightness value INTout(u, v) of the pixel in the enhanced brightness information BPL according to INTout(u, v)=INTin(u, v)×CFp.

[0078] The dimming circuit 150 determines the luminance of each light source element based on the enhanced brightness information BPL and the attenuation rate distribution information 171. In the dimming based on the local dimming control, the luminance of the light emitting element corresponding to the high brightness area of ​​the image becomes higher. Therefore, in the area where the brightness information INT is multiplied by a large coefficient, the result of the dimming is that the luminance of the light emitting element becomes higher. In this way, the luminance of the light emitting element corresponding to a specific area such as an area where an icon is displayed is enhanced.

[0079] In addition, the on / off of the region enhancement function can also be switched by register settings or the like. When the region enhancement function is set to on, the region enhancement process using the coefficients of each region is performed. When the region enhancement function is set to off, the region enhancement circuit 140 does not perform coefficient multiplication, or the coefficients of all regions are set to the same value. Figure 8 For example, when the area enhancement function is set to off, CF1 = CF2 = CF3 = CF4 = CF5 = C is set. C is an arbitrary number greater than or equal to 0 and less than or equal to 1, for example, 0.5.

[0080] In this embodiment, the regional enhancement circuit 140 performs the following regional enhancement processing: multiplying the brightness information INT in the first region by a first coefficient, and multiplying the brightness information INT in the second region of the input image different from the first region by a second coefficient. The dimming circuit 150 determines the light source brightness information based on the brightness information BPL after the regional enhancement processing.

[0081] According to the present embodiment, by multiplying the brightness information INT of each area by a coefficient, the brightness information INT of the area is enhanced, and the dimming process in the local dimming control is performed based on the enhanced brightness information BPL. As a result, in the area where the brightness of the image is enhanced, dimming is performed in a manner that the luminous brightness of the light source element becomes larger. In addition, the coefficient multiplied by the brightness information INT of each area can be different, so the degree of enhancement in each area can be different. For the area where enhancement is not performed, a coefficient corresponding to it can be set, and the luminous brightness of the area is not enhanced. The luminous brightness of the light source element is determined by the dimming process in the local dimming control for both the enhanced area and the non-enhanced area. Therefore, appropriate dimming is also performed in the non-enhanced area, and the display quality of the image is good.

[0082] In addition, the first area here is Figure 7 as well as Figure 8 The first region corresponds to any one of AR1 to AR5, and the second region corresponds to any one of AR1 to AR5 other than the first region.

[0083] In addition, in the present embodiment, the first coefficient may be larger than the second coefficient.

[0084] According to this embodiment, the light emission brightness in the first area can be enhanced compared to the light emission brightness in the second area. As a result, the visibility of the image in the first area is relatively higher than that of the image in the second area.

[0085] In addition, in the present embodiment, when the region enhancement process is not performed, the first coefficient may be the same value as the second coefficient.

[0086] According to the present embodiment, by setting the first coefficient to the same value as the second coefficient, the degree of enhancement in each region is the same. That is, the entire backlight 210 is dimmed by the dimming process in the local dimming control. In this way, the regional enhancement process can be turned off.

[0087] 4. Detailed Configuration Example 2

[0088] Fig. 9 This is the second detailed structural example of the circuit device. Figure 2 The same components will be described in detail as appropriate. Fig.10 and Fig.11 The example of region enhancement shown in the figure explains the operation of each unit. However, the number of regions to be enhanced may be one or more.

[0089] like Fig.10As shown, the first area AR1 to the third area AR3 are set. The first area AR1 to the third area AR3 are set for the input image, and the positions of the areas are shown corresponding to the positions on the backlight 210. The third area AR3 is an area other than the first area AR1 and the second area AR2 in the input image of one frame.

[0090] The storage unit 170 stores the initial value information 172b as the region enhancement information 172. Fig.11 As shown, the initial value information 172b is the initial value of the luminous brightness set for each area of ​​the first area AR1 to the third area AR3. The initial values ​​of the first area AR1 and the second area AR2, which are the enhancement objects, are set to the enhanced brightness values, and the initial value of the third area AR3, which is not the enhancement object, is set to zero. An example of the enhanced brightness value is the maximum value among the brightness values ​​that can be set as the luminous brightness of the light-emitting element. However, the enhanced brightness value is not limited to the maximum value as long as it is high brightness. The luminous brightness of the light-emitting element in the area that is not the enhancement object is determined by local dimming control, so its initial value may not necessarily be zero.

[0091] The regional enhancement circuit 140 sets the initial value of the luminous brightness of each light source element for the dimming circuit 150 based on the initial value information 172b. That is, the initial value of the luminous brightness of the light source elements corresponding to the first area AR1 and the second area AR2 is set to the enhanced brightness value, and the initial value of the luminous brightness of the light source elements corresponding to the third area AR3 is set to zero.

[0092] The dimming circuit 150 determines the luminous brightness of each light emitting element according to the set initial value, brightness information INT and attenuation rate distribution information 171. Specifically, the dimming circuit 150 does not change the luminous brightness of the light source elements in the first area AR1 and the second area AR2 whose initial values ​​are set to the enhanced brightness value. That is, after dimming based on local dimming control, the luminous brightness of the light source elements in the first area AR1 and the second area AR2 is the enhanced brightness value. The dimming circuit 150 dims the luminous brightness according to the brightness information INT and the attenuation rate distribution information 171 for the light source elements in the third area AR3 whose initial value is set to zero. The light source elements in the first area AR1 and the second area AR2 are not affected by local dimming and are fixed to the enhanced brightness value, so the brightness does not decrease due to local dimming. As a result, the luminous brightness of the light emitting elements corresponding to specific areas such as the area where icons are displayed is enhanced.

[0093] In addition, the on / off of the regional enhancement function can also be switched by register settings, etc. When the regional enhancement function is set to on, the regional enhancement processing using the initial values ​​of the above-mentioned regions is implemented. When the regional enhancement function is set to off, the regional enhancement circuit 140 sets the initial value of the luminous brightness of all light source elements to zero. Then, the dimming circuit 150 dims the luminous brightness of all light source elements according to the brightness information INT and the attenuation rate distribution information 171.

[0094] In the present embodiment, the regional enhancement circuit 140 performs a regional enhancement process of setting the emission brightness of the light source element corresponding to the first region to a predetermined enhanced brightness value.

[0095] According to this embodiment, by setting the light emission brightness of the light source element corresponding to the first area to the specified enhanced brightness value, the light emission brightness of the light source element corresponding to the first area becomes the specified enhanced brightness value regardless of the dimming process in the local dimming control. As a result, the light emission brightness of the light source element corresponding to the first area is enhanced.

[0096] In addition, the first area here corresponds to Fig.10 and Fig.11 Any one of AR1 and AR2.

[0097] In addition, in this embodiment, the dimming circuit 150 fixes the light emission brightness of the light source element corresponding to the first area to a specified enhanced brightness value, and determines the light emission brightness of the light source element corresponding to the second area of ​​the input image different from the first area based on the brightness information INT.

[0098] According to the present embodiment, the second region is a region where the regional enhancement processing is not performed, and the light luminance of the light source element corresponding to the second region is determined by the dimming circuit 150 according to the brightness information INT of the image data IMA. Thus, the displayed image is appropriately dimmed, and therefore, the image display quality is good in the region where the regional enhancement processing is not performed.

[0099] In addition, the first area here corresponds to Fig.10 and Fig.11 The second area corresponds to any one of AR1 and AR2, and the second area corresponds to AR3.

[0100] In addition, in the present embodiment, the predetermined enhanced brightness value may be the maximum value of the light emission brightness of the light source element.

[0101] According to this embodiment, the light emission brightness of the light source element corresponding to the first region is maximized by the region enhancement processing. Thus, even in a bright environment, the visibility of the image in the first region can be maximized. Fig.12When the light emitting brightness is determined by the dimming process described later, the light emitting brightness will not be dimmed in the direction of dimming as described in the following formula (2). That is, if the light emitting brightness is set to the maximum value as the initial value, the light emitting brightness will remain at the maximum value even if the light emitting element is dimmed.

[0102] 5. Dimming circuit and color correction circuit

[0103] Fig.12 This is the process flow of the dimming circuit. Figure 6 In the case of the first detailed structure example, the brightness information INT can be replaced with the brightness information BPL after the area enhancement processing. Fig.13 Examples of ambient light elements are shown. Fig.13 In the example, the x direction is the horizontal scanning direction of the display panel, and the y direction is the vertical scanning direction of the display panel. Here, the brightness information INT is not downsampled, and the number of pixels of the brightness information INT is the same as the number of pixels of the image data IMA. In this case, Fig.13 The (x, y) in is the coordinate on the brightness information INT, and is also the coordinate on the input image. In addition, when downsampling is performed, the coordinate in the brightness information INT after downsampling can be used instead of (x, y) in the dimming process.

[0104] In step S1, the dimming circuit 150 initializes the light source brightness information. Figure 6 In the first detailed configuration example, for example, the brightness values ​​of all light source elements are initialized to zero. Fig. 9 In the second detailed configuration example, the brightness value of each light source element is set to an initial value set by the regional enhancement circuit 140.

[0105] In step S2, the dimming circuit 150 selects one pixel from the pixels included in the brightness information INT. The selected pixel is referred to as an object pixel. In the loop from step S2 to step S5, the object pixels are selected in sequence. For example, in the first step S2, the first pixel of the first scanning line of the brightness information INT is selected, and in the subsequent steps S2, the second pixel, the third pixel, ... are selected in sequence. When all the pixels of the first scanning line are selected, the pixels of the second scanning line are selected in sequence, and the process is repeated until the final scanning line.

[0106] In step S3, the dimming circuit 150 selects n×m light source elements located around the target pixel. These n×m light source elements are also referred to as peripheral light source elements. n and m may be integers greater than or equal to 2.

[0107] like Fig.13As shown, the position of the object pixel 22 is set to (i, j). i and j are integers, and the position (i, j) indicates that it is the i-th pixel of the j-th scanning line. Fig.13 In the example, n=m=4. The dimming circuit 150 selects the light source elements L1 to L16 that are closest to the +x direction and the -x direction, and the closest to the +y direction and the -y direction, respectively, based on the position (i, j). When k is an integer greater than 1 and less than 16, the position of the light source element Lk is represented as (xk, yk).

[0108] exist Fig.12 In step S4 , the light source brightness information of each of the n×m light source elements selected in step S3 is updated using the pixel value of the target pixel 22 in the brightness information INT and the attenuation rate distribution information 171 stored in the storage unit 170 .

[0109] In step S5 , the light control circuit 150 determines whether all pixels are selected as target pixels, and ends the process if all pixels are selected, and returns to step S2 if there are unselected pixels.

[0110] The updating process of the light source brightness information in step S4 is described. The dimming circuit 150 obtains the required change amount Δ representing the required change amount of the light amount received by the target pixel 22 from the light source elements L1 to L16 according to the following equation (1): ij .

[0111]

[0112] In the above formula (1), INT ij It is the brightness value of the object pixel 22 in the brightness information INT. As described above, the brightness value is the maximum value among the RGB pixel values ​​of the object pixel 22 in the image data IMA. Alternatively, the brightness value may be a brightness value calculated by multiplying the RGB pixel values ​​of the object pixel 22 in the image data IMA by a coefficient, such as Y in the YCrCb space. lsf(k) is the attenuation rate of the light irradiated by the light source element Lk to the object pixel 22, and is obtained based on the actual attenuation rate distribution or the attenuation rate distribution after approximation. The dimming circuit 150 uses the attenuation rate distribution information 171 to obtain lsf(k). The attenuation rate distribution information 171 is a lookup table or a function. powc(k) is the last light source brightness information of the light source element Lk. The last light source brightness information is the light source brightness information calculated using the last object pixel selected before the current object pixel 22. The last object pixel is the pixel at position (i-1, j) which is one position before position (i, j) in the x direction.

[0113] The dimming circuit 150 converts the required change Δ into ijThe light source luminance information is allocated to the light source element Lk, thereby updating the light source luminance information.

[0114]

[0115] In the above formula (2), powu(k) is the current light source brightness information, that is, the updated light source brightness information.

[0116] Fig.14 This is the flow of the illumination brightness calculation process performed by the color correction circuit. Fig.13 However, the processing performed by the color correction circuit 120 is different from the processing performed by the dimming circuit 150. In the description of the dimming circuit 150, (x, y) is used as the coordinate on the brightness information INT, but here, (x, y) is the coordinate on the input image shown by the image data IMA.

[0117] In step S11, the color correction circuit 120 selects one pixel from the pixels included in the image data IMA. The selected pixel is referred to as an object pixel. In the loop from step S11 to step S14, the object pixels are selected in sequence. For example, in the first step S11, the first pixel of the first scanning line of the image data IMA is selected, and in the subsequent steps S11, the second pixel, the third pixel, ... are selected in sequence. When all the pixels of the first scanning line are selected, the pixels of the second scanning line are selected in sequence, and the process is repeated until the final scanning line.

[0118] In step S12, the color correction circuit 120 selects s×t light source elements located around the target pixel. These s×t light source elements are also referred to as peripheral light source elements. s and t may be integers greater than or equal to 2. Fig.13 An example where s=t=4 is shown.

[0119] The position of the object pixel 22 is represented as (i, j). i and j are integers, and the position (i, j) indicates that it is the i-th pixel of the j-th scanning line. The color correction circuit 120 selects the light source elements L1 to L16 that are closest to the +x direction and the -x direction, and the closest to the +y direction and the -y direction, respectively, based on the position (i, j). When β is an integer greater than or equal to 1 and less than or equal to 16, the position of the light source element Lβ is represented as (xβ, yβ).

[0120] In step S13 , the color correction circuit 120 obtains illumination brightness information of the target pixel using the light source brightness information of the selected s×t light source elements and the attenuation rate distribution information 171 .

[0121] In step S14 , the color correction circuit 120 determines whether all pixels are selected as target pixels, and ends the process if all pixels are selected, and returns to step S11 if there are unselected pixels.

[0122] The calculation process of the illumination brightness information in step S13 will be described. The color correction circuit 120 obtains the illumination brightness information of the target pixel 22 by the following equations (3) and (4).

[0123]

[0124] lsf(β)=lsf((i-xβ)2+(j-yβ)2)···(4)

[0125] In the above formula (3), PL(i, j) is the illumination brightness information for the pixel at position (i, j). pow(β) is the light source brightness information determined by the dimming circuit 150. lsf(β) is the attenuation rate of the light irradiated by the light source element Lβ to the target pixel 22. The color correction circuit 120 calculates lsf(β) using the attenuation rate distribution information 171. In the above formula (4), the square of the distance is used as the input of the lookup table, but the distance can also be used as the input of the lookup table.

[0126] In addition, Fig.12 After the loop of steps S2 to S5 in the process is executed to the last pixel of the brightness information INT, the powu of the above formula (4) is used as the pow of the above formula (3). In addition, even if the loop of steps S2 to S5 is not executed to the last pixel of the brightness information INT, since the update of the light source brightness information of the light source element is completed in sequence as the object pixel advances, the light source brightness information at which the update is completed can also be used as pow.

[0127] The color correction circuit 120 may obtain the illumination brightness information of the target pixel based not only on the light source brightness information of s×t light source elements located around the target pixel but also on the light source brightness information of all the light source elements of the backlight 210 .

[0128] 6. Detailed Structure Example 3

[0129] Fig.15 This is a third detailed configuration example of the circuit device. In this configuration example, in addition to local dimming, global dimming processing is also performed. Figure 2 , Figure 6 or Fig. 9 The description of the same components will be appropriately omitted. Fig.15 Shown in Figure 6 In the first detailed configuration example, an example of global dimming processing is combined, but it is also possible to Fig. 9 The same global dimming processing is combined in the second detailed structure example.

[0130] Processing device 300 performs global dimming processing based on information about the amount of ambient light detected by an external light sensor, etc., and sends the result as global dimming parameter DIMG to circuit device 100. However, circuit device 100 may perform global dimming processing based on information about the amount of ambient light and obtain global dimming parameter DIMG.

[0131] The dimming circuit 150 multiplies the light emission brightness of each light source element determined according to the brightness information INT by the global dimming parameter DIMG. The global dimming parameter is, for example, greater than 0 and less than 1 and is common to the entire backlight 210. The dimming circuit 150 outputs light source brightness information indicating the light emission brightness of each light source element multiplied by the global dimming parameter as light source brightness data DDIM.

[0132] In the present embodiment, the dimming circuit 150 performs a global dimming process based on the global dimming parameter DIMG on the light emission brightness of each light source element determined based on the brightness information INT, thereby determining the light source brightness information.

[0133] According to this embodiment, the luminous brightness of each light source element subjected to the regional enhancement processing is multiplied by the global dimming parameter. Thus, the regional enhancement processing, the dimming processing in the local dimming control, and the global dimming processing can be combined. The regional enhancement processing can improve the visibility of a specific area, and the brightness of the entire screen can be dimmed according to the brightness of the environment.

[0134] In addition, the present embodiment is described in detail as described above, but those skilled in the art can easily understand that various modifications can be made without substantially departing from the new matters and effects of the present disclosure. Therefore, all such modifications are included in the scope of the present disclosure. For example, in the specification or the drawings, a term recorded at least once together with a different term in a broader sense or synonymous can be replaced with the different term in any part of the specification or the drawings. In addition, all combinations of the present embodiment and the modifications are also included in the scope of the present disclosure. In addition, the structure and operation of the circuit device, backlight source, display device, display system, processing device, electronic device, etc. are not limited to the contents described in the present embodiment, and various modifications can be implemented.

Claims

1. A circuit device for controlling a display device including a plurality of light source elements and a display panel, characterized in that: The circuit device comprises: a brightness analysis circuit that performs brightness analysis on image data of an input image and outputs brightness information; a dimming circuit that determines light source brightness information representing the light emission brightness of each of the plurality of light source elements based on the brightness information; as well as A regional enhancement circuit performs the following regional enhancement processing on the dimming circuit: when the regional enhancement processing is performed on the first region of the input image, the luminous brightness of the light source element corresponding to the first region is increased compared to the case where the regional enhancement processing is not performed on the first region.

2. The circuit arrangement according to claim 1, characterized in that The region enhancement circuit performs the region enhancement processing of multiplying the brightness information in the first region by a first coefficient and multiplying the brightness information in a second region of the input image different from the first region by a second coefficient. The dimming circuit determines the light source brightness information according to the brightness information after the area enhancement process.

3. The circuit arrangement according to claim 2, characterized in that The first coefficient is greater than the second coefficient.

4. The circuit arrangement according to claim 2, characterized in that When the region enhancement process is not performed, the first coefficient has the same value as the second coefficient.

5. The circuit arrangement according to claim 1, characterized in that The area enhancement circuit performs the area enhancement process of setting the light emission luminance of the light source element corresponding to the first area to a predetermined enhanced luminance value.

6. The circuit arrangement according to claim 5, characterized in that The dimming circuit fixes the light emission brightness of the light source element corresponding to the first area to the specified enhanced brightness value, and determines the light emission brightness of the light source element corresponding to the second area of ​​the input image different from the first area based on the brightness information.

7. The circuit arrangement according to claim 5, characterized in that The prescribed enhanced brightness value is the maximum value of the light emission brightness of the light source element.

8. The circuit arrangement according to claim 1, characterized in that The region enhancement circuit performs the region enhancement process on the first region when it is determined that a predetermined icon is displayed in the first region.

9. The circuit arrangement according to claim 8, characterized in that When the first area is displayed in black, the area enhancement circuit does not perform the area enhancement process on the first area.

10. The circuit arrangement according to claim 1, characterized in that The dimming circuit determines the light source brightness information by performing a global dimming process based on a global dimming parameter on the light emission brightness of each light source element determined according to the brightness information.

11. The circuit arrangement according to claim 1, characterized in that The circuit device includes a color correction circuit, which performs color correction on the image data according to the light source brightness information.

12. A display system, characterized in that: It contains: The circuit arrangement of any one of claims 1 to 11; and The display device.

13. A display system, characterized in that: It contains: A display device comprising a plurality of light source elements and a display panel; as well as a display controller that controls the display device, The display controller sets the light emitting brightness of the light source element corresponding to the first area of ​​the display panel displaying the specified icon to high brightness, and performs local dimming control on the light emitting brightness of the light emitting element corresponding to the second area of ​​the display panel not displaying the specified icon based on the image data of the input image of the display controller.

14. The display system according to claim 13, characterized in that: The high brightness is a fixed brightness value that does not depend on the image data.

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