Circuit arrangement and display system

Abstract

Circuit device and display system. The circuit device includes a brightness analysis circuit, a dimming circuit, and a region enhancement circuit. The brightness analysis circuit performs brightness analysis on image data of an input image to output brightness information. The dimming circuit decides light source brightness information indicating luminance of light emission of each light source element of a plurality of light source elements based on the brightness information. The region enhancement circuit performs a region enhancement process on the dimming circuit. The region enhancement process is a process of making the luminance of light emission of the light source element corresponding to a first region of the input image higher than in a case where the region enhancement process is not performed on the first region.

Description

Technical Field

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

[0002] Patent Document 1 discloses an image display apparatus for improving the visibility of a specific image. The image display apparatus includes a display control unit. The display control unit controls a light source such that the brightness of a light-emitting region other than a first light-emitting region corresponding to a first display area of ​​the liquid crystal panel is lower than the brightness of the first light-emitting region. Furthermore, the display control unit controls the liquid crystal panel such that the transmittance of pixels other than those in the first display area of ​​the liquid crystal panel is lower than the transmittance of pixels in the first display area, and increases with distance from the first display area.

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

[0004] In Patent Document 1, the display control unit controls the brightness of the light source in a light-emitting area other than the first light-emitting area corresponding to the first display area of ​​the liquid crystal panel, independent of the displayed image. Therefore, even if the displayed image changes in an area outside the first display area, the brightness of the corresponding light source does not change, making it impossible to properly dim the displayed image. Consequently, there is a problem of poor display quality in areas outside the first display area. Summary of the Invention

[0005] One aspect of this disclosure relates to a circuit device for controlling a display device comprising a plurality of light source elements and a display panel. The circuit device includes: a brightness analysis circuit that performs brightness analysis on image data of an input image and outputs brightness information; a dimming circuit that determines, based on the brightness information, light source brightness information representing the luminous brightness of each of the plurality of light source elements; and a region enhancement circuit that performs region enhancement processing on the dimming circuit as follows: when the region enhancement processing is performed on a first region of the input image, compared to when the region enhancement processing is not performed on the first region, the luminous brightness of the light source element corresponding to the first region is increased.

[0006] Furthermore, another aspect of this disclosure relates to a display system comprising the aforementioned circuitry and the display device.

[0007] Furthermore, another aspect of this disclosure relates to a display system comprising: a display device including a plurality of light source elements and a display panel; and a display controller that controls the display device, wherein the display controller sets the luminous brightness of the light source element corresponding to a first area in the display panel that displays a specified icon to a high brightness, and performs local dimming control on the luminous brightness of the light source element corresponding to a second area in the display panel that does not display the specified icon based on image data of an input image of the display controller. Attached Figure Description

[0008] Figure 1 This is an example of the structure of an electronic device.

[0009] Figure 2 This is an example of the structure of a circuit device.

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

[0011] Figure 4 These are examples of images displayed on the display panel and areas that become area enhancement objects.

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

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

[0014] Figure 7 This is an example of region enhancement.

[0015] Figure 8 This is an example of region enhancement.

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

[0017] Figure 10 This is an example of region enhancement.

[0018] Figure 11 This is an example of region enhancement.

[0019] Figure 12 This is a flowchart of the processing performed by the dimming circuit.

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

[0021] Figure 14 This is a flowchart of the illumination brightness calculation process performed by the color correction circuit.

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

[0023] Label Explanation

[0024] 22 Object pixels; 100 Circuit devices; 120 Color correction circuit; 130 Brightness analysis circuit; 131 Brightness extraction unit; 132 Downsampling unit; 140 Area enhancement circuit; 150 Dimming circuit; 160 Area enhancement dimming unit; 170 Storage unit; 171 Attenuation rate distribution information; 172 Area enhancement information; 172a Coefficient information; 172b Initial value information; 200 Display device; 210 Backlight; 220 Display panel; 221; 222 Instruments; 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 Implementation

[0025] The preferred embodiments of this disclosure will now be described in detail. The embodiments described below are not intended to unduly limit the scope of the claims, and the structures described in these embodiments are not necessarily all essential structural elements.

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

[0027] Figure 1 This is a structural example of an electronic device that includes the display system of this embodiment. The electronic device 500 includes a processing unit 300 and a display system 400. As an example, the electronic device 500 is an in-vehicle 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 on a semiconductor substrate in which multiple circuit elements are integrated. Additionally, in Figure 1 The circuit device 100 and the display device 200 are described as different structural elements, but the circuit device 100 may also be included in the display device 200.

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

[0030] When viewed from above, the backlight 210 contains light source elements arranged in a two-dimensional configuration. These light source elements are light-emitting elements powered by electricity, such as inorganic light-emitting diodes (LEDs) or organic light-emitting diodes (OLEDs). In local dimming control, the light intensity of each of the two-dimensionally configured light source elements is controlled independently. Alternatively, the backlight 210 can be divided into multiple regions. When viewed from above, multiple light source elements are arranged in each region. The light source elements arranged within each region are controlled to the same light intensity, and the light intensity of each region is controlled independently.

[0031] One example of a two-dimensional arrangement of light source elements is a square arrangement in which light source elements are arranged at all intersections of multiple rows and columns. However, the two-dimensional arrangement is not limited to a square arrangement. For example, a two-dimensional arrangement can also be a configuration referred to as a rhombus arrangement or an alternating arrangement. In this arrangement, light source elements are arranged at the intersections of one side of the odd-numbered rows and even-numbered rows with odd-numbered columns, and at the intersections of the other side of the odd-numbered rows and even-numbered rows with even-numbered columns; no light source elements are arranged at other intersections.

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

[0033] Display panel 220 is an electro-optical panel that allows light from backlight 210 to pass through and displays images by controlling its transmittance. For example, display panel 220 is a liquid crystal display panel.

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

[0035] The processing device 300 sends image data IMA to the circuit device 100. The processing device 300 is a processor such as a CPU, GPU, microcomputer, DSP, ASIC, or FPGA. CPU is an abbreviation for Central Processing Unit. GPU is an abbreviation for Graphics Processing Unit. DSP is an abbreviation for Digital Signal Processor. ASIC is an abbreviation for Application-Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array.

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

[0037] Furthermore, the circuit device 100 has a built-in display controller function. That is, the circuit device 100 sends the image data IMB and the time control signal controlling the display time to the display driver 230. In addition, the circuit device 100 can also perform image processing such as grayscale correction, white balance correction, or scaling for the image data IMA or IMB. Alternatively, the circuit device 100 may not have a built-in display controller function, and the display controller may be a separate integrated circuit device. In this case, the display controller may also be included in the display device 200. Furthermore, the display controller and the display driver 230 may be composed of separate integrated circuit devices, or they may be composed of a single integrated circuit device.

[0038] 2. Example of circuit device structure

[0039] The following illustrations and descriptions of the display controller functions built into the circuit device 100 are omitted; instead, dimming and color correction are illustrated and described.

[0040] Figure 2 This is an example of the structure of a circuit device. The circuit device 100 includes a color correction circuit 120, a brightness analysis circuit 130, a local dimming enhancement unit 160, and a storage unit 170.

[0041] Storage unit 170 stores attenuation rate distribution information 171 and area enhancement information 172. Storage unit 170 is a register or memory. The memory is volatile memory such as RAM, or non-volatile memory such as OTP memory or EEPROM. RAM is an abbreviation for Random Access Memory. OTP is an abbreviation for One-Time Programmable Memory. EEPROM is an abbreviation for Electrically Erasable Programmable Read-Only Memory.

[0042] Attenuation rate distribution information 171 represents the attenuation rate distribution of light reaching the display panel from the light source element. The attenuation rate distribution represents the relationship between the distance from the light source element to the pixel and the attenuation rate of the light illuminating the pixel. The attenuation rate distribution is also referred to as attenuation characteristics or brightness distribution. Attenuation rate distribution information 171 can be, for example, a lookup table or function representing the attenuation rate distribution. If the function is a polynomial, the attenuation rate distribution information 171 can also be the coefficients of each term of that polynomial.

[0043] Region enhancement information 172 is used in the region enhancement process described later. Region enhancement information 172 contains information specifying the region to be enhanced. Additionally, region enhancement information 172 may also contain enhancement control information for each region. Enhancement control information, for example, is... Figure 6 The coefficient information 172a or mentioned later Figure 9 The initial value information 172b will be 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 called the input image. The image interface method can be various, such as LVDS, parallel RGB, or a display port. LVDS is an abbreviation for Low Voltage Differential Signaling.

[0045] The brightness analysis circuit 130 receives the received image data IMA as input. The brightness analysis circuit 130 analyzes the brightness of the image data IMA and outputs the result as brightness information INT. The brightness information represents the brightness of the image at various locations within the input image. Figure 3 A detailed structural example of a luminance analysis circuit is shown. The luminance analysis circuit 130 includes a luminance extraction unit 131 and a downsampling unit 132.

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

[0047] The downsampling unit 132 obtains a second brightness image by downsampling the first brightness image. The second brightness image has fewer pixels than the first brightness image. Downsampling only needs to be performed in at least one of the horizontal and vertical scanning directions. As an example, the number of pixels is downsampled to less than half in both the horizontal and vertical scanning directions. The downsampling unit 132 outputs the second brightness image as brightness information INT.

[0048] Furthermore, the structure of the brightness analysis circuit 130 is not limited to the above. For example, the downsampling unit 132 may be omitted, and the first brightness image may be output as brightness information INT.

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

[0050] The dimming circuit 150 generates light source brightness information representing the luminous brightness of each light-emitting element based on the brightness information INT, and outputs this 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 luminous brightness of each light source element. Details of this method will be described later. Alternatively, the dimming circuit 150 determines the maximum brightness of pixels belonging to the image area corresponding to the light-emitting element of the backlight 210 based on the brightness information INT. The dimming circuit 150 determines the maximum luminous brightness within the displayable range of the display device 200 and sets this luminous brightness as the luminous brightness of the light-emitting element.

[0051] The area enhancement circuit 140 performs area enhancement processing on the dimming circuit 150 based on the area enhancement information 172 stored in the storage unit 170. The dimming circuit 150 performs local dimming control on each light source element of the backlight 210. At this time, the area enhancement circuit 140 performs area enhancement processing in a manner that makes the luminous brightness of the light source element corresponding to a specific area higher than the luminous brightness without area enhancement processing. Area enhancement processing is implemented by controlling the input to the dimming circuit 150 or by controlling the dimming processing in the dimming circuit 150. The luminous brightness of the light source elements corresponding to areas other than the specific area is determined by dimming based on normal local dimming control. Figures 6-8 as well as Figures 9-11 The text provides a detailed example illustrating region enhancement processing.

[0052] The color correction circuit 120 calculates 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 of each pixel of the display panel 220 when the display panel 220 is illuminated by the backlight 210. Details of the illumination brightness calculation are provided in... Figure 14The following will describe the process. The color correction circuit 120 performs color correction on the image data IMA based on 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 reciprocal of the brightness of the light reaching that pixel, and uses the result as the new pixel data for that pixel. Furthermore, the image represented by the image data IMB is called the output image.

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

[0054] Furthermore, the color correction circuit 120, brightness analysis circuit 130, area enhancement circuit 140, and dimming circuit 150 are logic circuits that process digital signals. The color correction circuit 120, brightness analysis circuit 130, area enhancement circuit 140, and dimming circuit 150 can each be constructed from logic circuits, or some or all of them can be constructed from a single integrated logic circuit. Alternatively, the functions of these circuits can be implemented by executing an instruction set or program that describes the functions of the color correction circuit 120, brightness analysis circuit 130, area enhancement circuit 140, and dimming circuit 150 using 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 function of the circuit device 100 by executing an instruction set or program that describes the function of each part of the circuit device 100.

[0056] Figure 4 These are examples of images displayed on a display panel and areas that become the objects of area enhancement. Here, an example of a display device 200 as a vehicle cluster panel is shown.

[0057] The display panel 220 displays images of icons 224-229, including gauges 221 and 222, and warning lights. As an example, the background is black, but it is not limited to this. The area AR that becomes the area enhancement object is the area surrounding icons 224-229. Alternatively, an area can be set individually for each icon. Furthermore, the area AR can also be an area that only surrounds a portion of the icons 224-229.

[0058] Figure 5This diagram illustrates the relationship between the backlight and area enhancement. The backlight 210 includes multiple light source elements LG arranged in a two-dimensional configuration when viewed from above. The luminous intensity of the light source element LG corresponding to the area AR is enhanced. The light source element corresponding to the area AR is a light source element arranged overlapping with the area AR on the display panel 220 when viewed from above and with the backlight 210. For example, the correspondence between the coordinates of pixels in the image and the positions of each light source element is stored in the storage unit 170. Based on this correspondence information and information about the designated area AR, the light source element to be enhanced is determined.

[0059] In this embodiment, the circuit device 100 controls the display device 200, which includes multiple 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 region 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 of the multiple light source elements LG, based on the brightness information INT. The region enhancement circuit 140 performs region enhancement processing on the dimming circuit 150. The region enhancement processing is performed such that, when region enhancement processing is performed on a 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 region enhancement processing is not performed on the first region.

[0060] According to this embodiment, the light source element corresponding to the first region has its brightness increased through region enhancement processing, thus the image in the first region is displayed brightly. Therefore, the visibility of the image in the first region is improved even in bright environments. Furthermore, the brightness of the light source element corresponding to the region without region enhancement processing is determined by the dimming circuit 150 based on the brightness information INT of the image data IMA. Therefore, the displayed image is appropriately dimmed, resulting in good image display quality in the regions without region enhancement processing.

[0061] In addition, the first region and Figure 4 as well as Figure 5 The AR correspondence. Or, the first region corresponds to the one described later. Figure 7 AR1 to AR4 or as described later Figure 10 Any one of AR1 and AR2.

[0062] In addition, in this embodiment, the area enhancement circuit 140 may also perform area enhancement processing for the first area when it is determined that a specified icon is displayed in the first area.

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

[0064] According to this embodiment, when an icon is displayed in the first region, the visibility of the icon is improved by region enhancement. On the other hand, when no icon is displayed in the first region, no region enhancement is performed; therefore, the luminous intensity of the light source element corresponding to the first region is suppressed, for example, suppressing the generation of halos. A halo is a phenomenon in which the periphery of an icon or text appears blurred due to light leakage from its periphery.

[0065] Alternatively, in this embodiment, the area enhancement circuit 140 may not perform area enhancement processing for the first area when the first area is displayed as black.

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

[0067] According to this embodiment, when the first region is not black, the area enhancement circuit 140 determines that a specified icon is displayed in the first region and performs area enhancement processing for the first region. On the other hand, when the first region is black, the area enhancement circuit 140 determines that a specified icon is not displayed in the first region and does not perform area enhancement processing for the first region.

[0068] In this embodiment, the display system 400 includes: a display device 200 comprising 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 brightness of the light source element LG corresponding to the first area of ​​the display panel 220 that displays a specified icon to a high brightness. Based on the image data IMA of the input image, the display controller performs local dimming control on the brightness of the light source element corresponding to the second area of ​​the display panel 220 that does not display a specified icon. Furthermore, this display controller corresponds to the circuit device 100 of this embodiment.

[0069] According to this embodiment, the light source element corresponding to the first area displaying the specified icon is set to high brightness, thus the specified icon in the first area is brightly displayed. Therefore, the visibility of the image in the first area is improved even in bright environments. Furthermore, local dimming control is performed on the luminance of the light source element corresponding to the second area where the specified icon is not displayed, based on image data IMA. This results in appropriate dimming of the displayed image, thus ensuring good image display quality in the second area where the specified icon is not displayed.

[0070] Furthermore, in this embodiment, the aforementioned high brightness can also be a fixed brightness value independent of the image data IMA. For example, it can also be... Figure 11 The brightness value is increased according to the regulations described later.

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

[0072] 3. Detailed structural example 1

[0073] Figure 6 This is the first detailed structural example of a circuit device. (Regarding...) Figure 2 The same constituent elements will have their descriptions omitted as appropriate. Hereafter, we will use... Figure 7 and Figure 8 The example shown illustrates the action of each part. However, it is sufficient to enhance only one or more regions.

[0074] like Figure 7 As shown, regions AR1 to AR5 are defined for the input image based on image data IMA. Regions AR1 to AR4 are non-overlapping rectangular regions. Region AR5 is the region in one frame of the input image excluding regions AR1 to AR4.

[0075] The brightness analysis circuit 130 outputs downsampled brightness information INT as described above. Regions AR1 to AR5 in the brightness information INT are determined by the pixel ratio of the input image to the brightness information INT. Additionally, an example of specifying regions using coordinates on the input image is shown here, but regions can also be specified initially using coordinates on the brightness information INT.

[0076] Storage unit 170 stores coefficient information 172a as region enhancement information 172. For example... Figure 8As shown, coefficient information 172a specifies the first coefficient CF1 to the fifth coefficient CF5 for each of the first region AR1 to the fifth region AR5. Each coefficient is between 0 and 1. Figure 8 An example of a coefficient is shown. For instance, a coefficient greater than 0.5 is set for areas where the luminous intensity is to be increased. Conversely, a coefficient less than 0.5 is set for areas where the luminous intensity is to be decreased. The baseline coefficient is not limited to 0.5.

[0077] The region 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 pixels 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 between 1 and 5, and (u, v) belong to the p-th region ARp. At this time, the region enhancement circuit 140 calculates the brightness value INTout(u, v) of the pixels 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 dimming based on local dimming control, the luminance of the light source element corresponding to the high-brightness area of ​​the image increases. Therefore, in areas where the brightness information INT is multiplied by a large coefficient, the result of dimming is that the luminance of the light source element increases. In this way, the luminance of the light source element corresponding to specific areas such as the area displaying icons is enhanced.

[0079] Furthermore, the activation / deactivation of the region enhancement function can be toggled via register settings. When the region enhancement function is enabled, region enhancement processing using the coefficients of the aforementioned regions is implemented. When the region enhancement function is disabled, 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 feature is set to off, the settings are CF1=CF2=CF3=CF4=CF5=C. C is any number greater than 0 and less than 1, such as 0.5.

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

[0081] According to this embodiment, by multiplying the luminance information INT of each region by a coefficient, the luminance information INT of that region is enhanced, and dimming processing in local dimming control is performed based on the enhanced luminance information BPL. Therefore, in areas where the image brightness is enhanced, dimming is performed by increasing the luminance of the light source element. Furthermore, the coefficient multiplied with the luminance information INT of each region can be different, thus allowing for different degrees of enhancement in each region. For regions that are not enhanced, a corresponding coefficient can be set, and no luminance enhancement is performed in those regions. The luminance of the light source element is determined by the dimming processing in local dimming control for both enhanced and unenhanced regions. Therefore, appropriate dimming is performed even in unenhanced areas, resulting in good image display quality.

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

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

[0084] According to this embodiment, the luminance of the first region can be enhanced compared to the luminance of the second region. Therefore, the visibility of the image in the first region is relatively higher than that of the image in the second region.

[0085] In addition, in this embodiment, when no region enhancement processing is performed, the first coefficient can also be the same value as the second coefficient.

[0086] According to this embodiment, by setting the first coefficient to the same value as the second coefficient, the enhancement level in each region is the same. That is, the backlight 210 is dimmed as a whole through dimming processing in local dimming control. In this way, regional enhancement processing can be turned off.

[0087] 4. Detailed structural example 2

[0088] Figure 9 This is the second detailed structural example of a circuit device. (Regarding...) Figure 2 The same constituent elements will have their descriptions omitted as appropriate. Hereafter, we will use... Figure 10 and Figure 11 The example shown illustrates the actions of each part. It is sufficient that at least one region is enhanced.

[0089] like Figure 10As shown, regions AR1 to AR3 are defined. Regions AR1 to AR3 are defined for the input image, and the positions of each region are illustrated in relation to their positions on the backlight 210. Region AR3 is the region in one frame of the input image that is excluding regions AR1 and AR2.

[0090] Storage unit 170 stores initial value information 172b as region enhancement information 172. For example... Figure 11 As shown, initial value information 172b sets the initial brightness values ​​for each of the three regions, AR1 (first region) to AR3 (third region). The initial values ​​for AR1 (first region) and AR2 (second region), which are targeted for enhancement, are set to enhanced brightness values, while the initial value for AR3 (third region), which is not targeted for enhancement, is set to zero. An example of an enhanced brightness value is the maximum value among the brightness values ​​that can be set to for the light-emitting element. However, any enhanced brightness value is acceptable and is not limited to the maximum value. The brightness of the light-emitting elements in regions not targeted for enhancement is determined by local dimming control; therefore, their initial values ​​may not necessarily be zero.

[0091] The area enhancement circuit 140 sets the initial value of the luminous brightness of each light source element to 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 element corresponding to the third area AR3 is set to zero.

[0092] The dimming circuit 150 determines the luminous brightness of each light-emitting element based on 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-emitting elements in the first region AR1 and the second region AR2, whose initial value is set to an enhanced brightness value. That is, after dimming based on local dimming control, the luminous brightness of the light-emitting elements in the first region AR1 and the second region AR2 is the enhanced brightness value. The dimming circuit 150 dims the luminous brightness of the light-emitting element in the third region AR3, whose initial value is set to zero, based on the brightness information INT and attenuation rate distribution information 171. The light-emitting elements in the first region AR1 and the second region AR2 are fixed at the enhanced brightness value without being affected by local dimming, 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 displaying icons is enhanced.

[0093] Furthermore, the activation / deactivation of the area enhancement function can be switched via register settings, etc. When the area enhancement function is set to Activated, area enhancement processing using the initial values ​​of each of the aforementioned areas is implemented. When the area enhancement function is set to Deactivated, the area enhancement circuit 140 sets the initial value of the luminance of all light source elements to zero. Then, the dimming circuit 150 dims the luminance of all light source elements based on the luminance information INT and the attenuation rate distribution information 171.

[0094] In this embodiment, the area enhancement circuit 140 performs area enhancement processing to set the luminous brightness of the light source element corresponding to the first area to a predetermined enhancement brightness value.

[0095] According to this embodiment, by setting the luminance of the light source element corresponding to the first region to a predetermined enhanced brightness value, the luminance of the light source element corresponding to the first region becomes the predetermined enhanced brightness value regardless of the dimming process in the local dimming control. Therefore, the luminance of the light source element corresponding to the first region is enhanced.

[0096] Additionally, the first region here corresponds to Figure 10 and Figure 11 Either AR1 or AR2.

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

[0098] According to this embodiment, the second region is a region where no region enhancement processing is performed, and the luminance of the light source element corresponding to this second region is determined by the dimming circuit 150 based on the luminance information INT of the image data IMA. Therefore, the displayed image is appropriately dimmed, resulting in good image display quality in the region where no region enhancement processing is performed.

[0099] Additionally, the first region here corresponds to Figure 10 and Figure 11 The second region corresponds to either AR1 or AR2, and the second region corresponds to AR3.

[0100] In addition, in this embodiment, the enhanced brightness value can also be the maximum value of the luminous brightness of the light source element.

[0101] According to this embodiment, the luminance of the light source element corresponding to the first region is maximized through region enhancement processing. Therefore, even in bright surrounding environments, the visibility of the image in the first region can be maximized. Furthermore, through... Figure 12When the dimming process described later determines the luminous brightness, as explained in equation (2), dimming will not be performed in the direction of dimming the luminous brightness. That is, if the luminous brightness is set to the maximum value as the initial value, the luminous brightness will remain at the maximum value even if the luminous element is dimmed.

[0102] 5. Dimming circuit and color correction circuit

[0103] Figure 12 This describes the processing flow performed by the dimming circuit. The following describes the process in use... Figure 6 In the case of the first detailed structure example, simply replace the luminance information INT with the luminance information BPL after area enhancement processing. Additionally, the following uses... Figure 13 An example of an ambient light source element is shown. Figure 13 In this context, the x-direction is the horizontal scanning direction of the display panel, and the y-direction is the vertical scanning direction. Here, the brightness information INT is not downsampled; the number of pixels in the brightness information INT is the same as the number of pixels in the image data IMA. In this case, Figure 13 In this context, (x, y) are the coordinates on the brightness information INT, and also the coordinates on the input image. Furthermore, when downsampling is performed, the coordinates in the downsampled brightness information INT can be used instead of (x, y) during dimming processing.

[0104] In step S1, the dimming circuit 150 initializes the light source brightness information. Figure 6 In the first detailed structural example, for instance, the brightness values ​​of all light source elements are initialized to zero. Figure 9 In the second detailed structural example, the brightness value of each light source element is set to an initial value set by the area 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 called the target pixel. In the loop from step S2 to step S5, the target pixels are selected sequentially. For example, in the initial step S2, the first pixel of the first scan line of the brightness information INT is selected, and in subsequent steps S2, the second pixel, the third pixel, and so on are selected sequentially. When all pixels of the first scan line have been selected, pixels of the second scan line are selected sequentially, and so on, until the final scan 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 surrounding light source elements. n and m can be integers greater than or equal to 2.

[0107] like Figure 13As shown, the position of 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 on the j-th scan line. Figure 13 In the example, n = m = 4. The dimming circuit 150 selects the light source elements L1 to L16, which are the two nearest columns in the +x and -x directions and the two nearest rows in the +y and -y directions, 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 Figure 12 In step S4, the pixel value of the object pixel 22 in the brightness information INT and the attenuation rate distribution information 171 stored in the storage unit 170 are used to update the light source brightness information of each of the n×m light source elements selected in step S3.

[0109] In step S5, the dimming circuit 150 determines whether all pixels have been selected as the target pixels. If all pixels have been selected, the process ends; otherwise, it returns to step S2.

[0110] Explain the update processing of the light source brightness information in step S4. The dimming circuit 150 calculates the required change Δ of the amount of light received by the target pixel 22 from the light source elements L1 to L16 according to the following formula (1). ij .

[0111]

[0112] In equation (1) above, INT ij This is the brightness value of the object pixel 22 in the brightness information INT. As mentioned 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 can also be 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 onto the object pixel 22, which is obtained based on the actual attenuation rate distribution or an approximation of it. 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 function. powc(k) is the previous light source brightness information of the light source element Lk. The previous light source brightness information is the light source brightness information calculated using the previous object pixel selected before the current object pixel 22. The previous object pixel is the pixel at position (i-1, j) one position before position (i, j) in the x-direction.

[0113] The dimming circuit 150, according to the following formula (2), will adjust the required change Δ ijThe light source brightness information is assigned to the light source element Lk, thereby updating the light source brightness information.

[0114]

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

[0116] Figure 14 This describes the process of calculating lighting brightness using a color correction circuit. (The last sentence is a repetition of the first and can be omitted.) Figure 13 For example, however, the processing performed by the color correction circuit 120 is different from the processing performed by the dimming circuit 150. Furthermore, in the description of the dimming circuit 150, (x, y) is used as the coordinates on the brightness information INT; however, here, (x, y) are the coordinates 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 contained in the image data IMA. The selected pixel is called the target pixel. In the loop from step S11 to step S14, the target pixels are selected sequentially. For example, in the initial step S11, the first pixel of the first scan line of the image data IMA is selected, and in subsequent steps S11, the second pixel, the third pixel, and so on are selected sequentially. When all the pixels of the first scan line have been selected, the pixels of the second scan line are selected sequentially, and so on until the final scan 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 surrounding light source elements. s and t can be integers greater than or equal to 2. Figure 13 This represents an example where s = t = 4.

[0119] Let the position of object pixel 22 be (i, j). i and j are integers, and the position (i, j) represents the i-th pixel of the j-th scan line. The color correction circuit 120 selects light source elements L1 to L16, based on the position (i, j), which are the two nearest columns in the +x and -x directions and the two nearest rows in the +y and -y directions, respectively. When β is an integer greater than 1 and less than 16, the position of the light source element Lβ is represented as (xβ, yβ).

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

[0121] In step S14, the color correction circuit 120 determines whether all pixels have been selected as the target pixels. If all pixels have been selected, the process ends; otherwise, it returns to step S11.

[0122] The calculation and processing of illumination brightness information in step S13 is explained. The color correction circuit 120 calculates the illumination brightness information of the object pixel 22 using the following formulas (3) and (4).

[0123]

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

[0125] In equation (3) above, 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 onto the target pixel 22. The color correction circuit 120 uses the attenuation rate distribution information 171 to calculate lsf(β). In equation (4) above, the square of the distance is used as the input to the lookup table, but the distance can also be used as the input to the lookup table.

[0126] In addition, Figure 12 The powu of equation (4) after the loop of steps S2 to S5 in the process reaches the last pixel of the brightness information INT is used as the pow of equation (3). In addition, even if the loop of steps S2 to S5 does not reach the last pixel of the brightness information INT, since the update of the light source brightness information of the light source element ends sequentially as the object pixel moves forward, the light source brightness information that has finished updating can also be used as pow.

[0127] The color correction circuit 120 can also determine the illumination brightness information of the object pixel not only based on the light source brightness information of the s×t light source elements surrounding the object pixel, but also based on the light source brightness information of all light source elements of the backlight 210.

[0128] 6. Detailed structural example #3

[0129] Figure 15 This is the third detailed structural example of the circuit device. In this structural example, global dimming processing is performed in addition to local dimming. Furthermore, regarding... Figure 2 , Figure 6 or Figure 9 For identical constituent elements, their descriptions may be omitted as appropriate. Figure 15 Shown in Figure 6 The first detailed structural example combines an example of global dimming processing, but it can also be found in... Figure 9 The same global dimming process is combined in the second detailed structural example.

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

[0131] The dimming circuit 150 multiplies the luminance of each light source element, determined based on the luminance information INT, by a global dimming parameter DIMG. The global dimming parameter is, for example, greater than or equal to 0 and less than or equal to 1, and is universally applicable to the backlight 210. The dimming circuit 150 outputs light source luminance information, representing the luminance of each light source element multiplied by the global dimming parameter, as light source luminance data DDIM.

[0132] In this embodiment, the dimming circuit 150 performs global dimming processing based on the global dimming parameter DIMG on the luminance of each light source element determined by the luminance information INT, thereby determining the light source luminance information.

[0133] According to this embodiment, the luminance of each light source element that has undergone area enhancement processing is multiplied by a global dimming parameter. This allows for the combination of area enhancement processing, dimming processing in local dimming control, and global dimming processing. Area enhancement processing can improve the visibility of specific areas, and it also allows for dimming of the overall screen brightness based on the ambient light.

[0134] Furthermore, while this embodiment has been described in detail above, those skilled in the art will readily understand that various modifications can be made without substantially departing from the new aspects and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, in the specification or drawings, a term described at least once with a different term that is more general or synonymous can be replaced with that different term anywhere in the specification or drawings. Additionally, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. Furthermore, the structure and operation of circuit devices, backlights, display devices, display systems, processing devices, and electronic devices are not limited to those described in this embodiment, and various modifications can be implemented.

Claims

1. A circuit device for controlling a display device comprising a plurality of light source elements and a display panel, characterized in that, The circuit device includes: A brightness analysis circuit that performs brightness analysis on the image data of an input image and outputs brightness information; A dimming circuit determines light source brightness information, representing the luminous brightness of each of the plurality of light source elements, based on the brightness information and attenuation rate distribution information, wherein the attenuation rate distribution information represents the attenuation rate distribution of light reaching the display panel from the plurality of light source elements. A region enhancement circuit performs the following region enhancement processing on the dimming circuit: when the region 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 region enhancement processing is not performed on the first region; as well as The color correction circuit calculates illumination brightness information based on the light source brightness information and the attenuation rate distribution information, performs color correction on the image data based on the illumination brightness information, and outputs the corrected image data. The region enhancement circuit performs region enhancement processing, setting the luminance of the light source element corresponding to the first region to a predetermined enhancement brightness value. This predetermined enhancement brightness value is a fixed brightness value independent of the image data. The dimming circuit fixes the luminance of the light source element corresponding to the first region to the specified enhanced brightness value, and determines the luminance of the light source element corresponding to the second region of the input image that is different from the first region based on the brightness information.

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

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

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

5. The circuit device according to claim 1, characterized in that, The specified enhanced brightness value is the maximum value of the luminous brightness of the light source element.

6. The circuit device according to claim 1, characterized in that, When the region enhancement circuit determines that a specified icon is to be displayed in the first region, it performs the region enhancement processing for the first region.

7. The circuit device according to claim 6, characterized in that, When the first region is displayed in black, the region enhancement circuit does not perform the region enhancement processing on the first region.

8. The circuit device according to claim 1, characterized in that, The dimming circuit determines the light source brightness information by performing global dimming processing based on global dimming parameters on the luminous brightness of each light source element determined according to the brightness information.

9. A display system, characterized in that, It includes: The circuit device according to any one of claims 1 to 8; and The display device.

Images