Circuit arrangement and display system

Abstract

A circuit device and a display system are provided. The circuit device includes a storage section that stores a plurality of lookup tables, and a luminance information operation circuit that operates luminance information indicating a luminance of light reaching a target pixel of a display panel from a backlight. A first lookup table corresponds to a first light source element disposed at a first position and indicates a first attenuation rate distribution of the first light source element. A second lookup table corresponds to a second light source element disposed at a second position and indicates a second attenuation rate distribution of the second light source element. The luminance information operation circuit obtains a first attenuation rate of light reaching the target pixel from the first light source element based on the first lookup table, obtains a second attenuation rate of light reaching the target pixel from the second light source element based on the second lookup table, and operates the luminance information based on the first attenuation rate and the second attenuation rate.

Description

Technical Field

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

[0002] Patent Document 1 discloses an image display device that performs local dimming. The image display device includes an LED output value calculation unit, a display brightness data calculation unit, and an LDC data calculation unit. The LED output value calculation unit calculates luminance data, representing the brightness of the light source corresponding to each region of the image when it emits light. The display brightness data calculation unit calculates diffuse brightness data by performing convolution processing on the luminance data using a pre-prepared brightness spread function. The linear interpolation unit performs linear interpolation processing on the diffuse brightness data to calculate data representing the value of each pixel for each primary color, i.e., display brightness data. The LDC data calculation unit calculates the transmittance of each pixel for each primary color based on the input image data and the display brightness data, and outputs data representing this transmittance as LCD data.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-095559

[0004] Multiple light sources are configured in the backlight, and the peripheral structure of each light source varies depending on its position. Therefore, the diffusion pattern of light reaching the display panel differs depending on the peripheral structure. If the brightness of the light reaching each pixel from the backlight is calculated without considering these differences in diffusion patterns, it becomes impossible to calculate this brightness with high precision. Since color correction of image data is based on the brightness of the light reaching each pixel, proper color correction is impossible if this brightness cannot be calculated with high precision. Patent Document 1 neither discloses nor provides any guidance on considering the differences in light diffusion patterns corresponding to the position of the light source when calculating the brightness of the light reaching each pixel from the backlight. Summary of the Invention

[0005] One aspect of this disclosure relates to a circuit device comprising: a storage unit storing a plurality of lookup tables, each lookup table representing the attenuation rate distribution of a light source element of the backlight of a display device having a display panel and a backlight; and a brightness information calculation circuit that calculates brightness information representing the brightness of light reaching an object pixel from the backlight to the display panel. The storage unit stores a first lookup table and a second lookup table as the plurality of lookup tables. The first lookup table corresponds to a first light source element disposed at a first position of the backlight and represents a first attenuation rate distribution of the first light source element. The second lookup table corresponds to a second light source element disposed at a second position of the backlight, different from the first position, and represents a second attenuation rate distribution of the second light source element. The brightness information calculation circuit calculates a first attenuation rate of light reaching the object pixel from the first light source element based on the first lookup table, calculates a second attenuation rate of light reaching the object pixel from the second light source element based on the second lookup table, and calculates the brightness information based on the first attenuation rate and the second attenuation rate.

[0006] In addition, another aspect of this disclosure relates to a display system comprising the aforementioned circuitry and the display device. Attached Figure Description

[0007] Figure 1 This is a structural example of an electronic device that includes the display system of this embodiment.

[0008] Figure 2 This is a detailed structural example of a circuit device.

[0009] Figure 3 This is a flowchart of the brightness information processing circuit.

[0010] Figure 4 This is a graph illustrating the differences in attenuation rate distribution corresponding to the position of the light source element.

[0011] Figure 5 It is a diagram illustrating the attenuation rate distribution of anisotropy.

[0012] Figure 6 This is an example of a lookup table corresponding to light source elements that are far from the edges and corners.

[0013] Figure 7 This is an example of a lookup table corresponding to light source elements arranged along the edge.

[0014] Figure 8 This is an example of a lookup table corresponding to a light source element located at a corner.

[0015] Figure 9 This is a diagram illustrating the rotation of the lookup table corresponding to the light source elements arranged along the edge.

[0016] Figure 10 This is a diagram illustrating the rotation of the lookup table corresponding to the light source elements located at the corners.

[0017] Figure 11 This is an explanatory diagram illustrating the method for determining the light source element used in brightness calculation.

[0018] Figure 12 It is a diagram illustrating the distance between the object pixel and each light source element in the light source element group.

[0019] Figure 13 This is a diagram illustrating the calculation method for linear interpolation.

[0020] Figure 14 This is a diagram illustrating a specific calculation example of linear interpolation.

[0021] Label Explanation

[0022] 10: Light source element; 15: Light source element group; 20: Object pixel; 100: Circuit device; 110: Interface circuit; 130: Light source control circuit; 140: Brightness analysis circuit; 141: Image analysis unit; 142: Light source brightness determination unit; 150: Brightness information calculation circuit; 151: Coordinate analysis unit; 152: Brightness calculation unit; 160: Color correction circuit; 170: Storage unit; 200: Display device; 210: Backlight; 220: Display panel; 230: 240: Display driver; 250: Display controller; 270: Structure; 300: Processing device; 400: Display system; 500: Electronic device; CAN, CNB, CNC, CND: Corner; DDIM: Dimming data; DFPA, DFPB, DFPC: Attenuation rate distribution; EDA, EDB, EDC, EDD: Edge; IMA, IMB: Image data; LLD: Dimming data; LUTA, LUTB, LUTC: Lookup table. Detailed Implementation

[0023] Preferred embodiments of this disclosure will be described in detail below. Furthermore, the embodiments described below do not unduly limit the scope of the claims, and the structures described in these embodiments are not necessarily all essential components.

[0024] 1. Electronic equipment, display systems and circuit devices

[0025] 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 includes an in-vehicle cluster panel including a display, an in-vehicle display device including a head-up display, a television device, or an information processing device with a display.

[0026] 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 In this document, the circuit device 100 and the display device 200 are described as different components, but the circuit device 100 may also be included within the display device 200.

[0027] Display device 200 includes a backlight 210, a display panel 220, a display driver 230, a light source driver 240, and a display controller 250. One example of display device 200 is a monitor for a television device or an information processing device. Alternatively, display device 200 may be a head-mounted display including a projection device to the eyes, or a head-up display including a projection device to a screen. When display device 200 is a head-up display, it further includes an optical system for projecting light emitted from backlight 210 and transmitted through display panel 220 onto a screen.

[0028] When viewed from above, the backlight 210 contains light source elements arranged in a two-dimensional manner. These light source elements are light-emitting elements that emit light via electrical supply, such as inorganic light-emitting diodes (LEDs) or organic light-emitting diodes (OLEDs). In local dimming control, the light intensity of each light source element arranged in a two-dimensional manner is controlled independently. Alternatively, when viewed from above, the backlight can be divided into multiple regions, each containing multiple light source elements, with the light source elements in each region controlled to the same light intensity, and the light intensity of each region controlled independently.

[0029] One example of a two-dimensional arrangement of light source elements is a square arrangement where 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, for example, a diamond arrangement or an alternating arrangement. In this arrangement, light source elements are arranged at the intersections of one of the odd-numbered rows and even-numbered rows with odd-numbered columns, and at the intersections of the other odd-numbered rows and even-numbered columns with even-numbered columns; no light source elements are arranged at other intersections.

[0030] The light source driver 240 receives dimming data DDIM from the circuit device 100 and drives each light source element of the backlight 210 based on the dimming 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 a different integrated circuit device.

[0031] Display panel 220 is an electro-optical panel that transmits light from backlight 210 and displays images by controlling its transmittance. For example, display panel 220 is a liquid crystal display panel.

[0032] The display controller 250 receives image data IMB from the circuit device 100 and sends the image data IMB and a timing control signal for controlling the display timing to the display driver 230. Additionally, the display controller 250 can perform image processing on the received image data IMB, such as grayscale correction, white balance correction, or zooming.

[0033] The display driver 230 drives the display panel based on received image data and timing control signals, thereby enabling the display panel 220 to display images. Furthermore, the display controller 250 and the display driver 230 can each be composed of different integrated circuit devices, or they can be composed of a single integrated circuit device.

[0034] The processing device 300 sends image data IMA to the circuit device 100. The processing device 300 is, for example, a processor such as a CPU, microcomputer, DSP, ASIC, or FPGA.

[0035] 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 analyzes the brightness of the image data IMA to determine the luminous brightness of each light source element or area of ​​the backlight 210 as dimming information, and outputs dimming data DDIM representing this dimming information to the light source driver 240. Furthermore, the circuit device 100 performs color correction on the image data IMA based on the dimming information and outputs the color-corrected image data IMB to the display controller 250.

[0036] Figure 2 This is a detailed structural example of the circuit device. The circuit device 100 includes an interface circuit 110, a light source control circuit 130, a brightness analysis circuit 140, a brightness information calculation circuit 150, a color correction circuit 160, and a storage unit 170. Hereinafter, the example of dimming each light-emitting element of the backlight 210 independently in local dimming will be described, but dimming can also be performed independently for each area containing multiple light-emitting elements.

[0037] The interface circuit 110 receives image data IMA from the processing device 300. The interface circuit 110 can be an interface circuit for various image interface methods such as LVDS, parallel RGB, or display port.

[0038] The brightness analysis circuit 140 includes an image analysis unit 141 and a light source brightness determination unit 142. The image analysis unit 141 analyzes the brightness of the image data IMB. The light source brightness determination unit 142 determines the luminous brightness of each light-emitting element based on the analysis results of the image analysis unit 141, and outputs dimming data LLD representing the luminous brightness of each light-emitting element as dimming information. For example, the image analysis unit 141 determines the maximum brightness of pixel data belonging to the image area corresponding to the light-emitting element of the backlight 210. The light source brightness determination unit 142 determines the minimum luminous brightness within the range that the display device 200 can display the maximum brightness, and uses it as the luminous brightness of the light-emitting element.

[0039] The light source control circuit 130 outputs dimming data DDIM, representing the luminous intensity of each light source element, to the light source driver 240 based on dimming data LLD, which represents the luminous intensity of each light source element. The light source driver 240 drives each light-emitting element using a PWM signal with a pulse width corresponding to the luminous intensity of each light source element shown in the dimming data DDIM. As a result, each light-emitting element emits light at a luminous intensity controlled by local dimming.

[0040] The storage unit 170 stores a lookup table representing the attenuation rate distribution of light from the light source element to the display panel. Figure 2 Examples of three lookup tables (LUTA, LUTB, and LUTC) with different attenuation rate distributions stored in the storage unit 170 are shown. However, the number of lookup tables can be two or more. 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 reaching the pixel from the light source element. The attenuation rate distribution is also called attenuation characteristics or luminance distribution. The storage unit 170 can be a register, or it can be memory such as RAM or non-volatile memory.

[0041] The brightness information processing circuit 150 includes a coordinate analysis unit 151 and a brightness calculation unit 152. Details are available in... Figure 3 This will be explained later; a brief overview is provided here. The coordinate analysis unit 151 determines which lookup table—LUTA, LUTB, or LUTC—to use based on the coordinates of the light source element. The brightness calculation unit 152 calculates brightness information representing the brightness of light reaching each pixel of the display panel 220 from the light source element based on the lookup table determined by the coordinate analysis unit 151 and the dimming data LLD, and outputs this brightness information as illumination brightness data LPX.

[0042] The color correction circuit 160 performs color correction on the image data IMA based on the illumination brightness data LPX, and outputs the corrected image data IMB to the display driver 230. Specifically, the color correction circuit 160 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.

[0043] The light source control circuit 130, brightness analysis circuit 140, brightness information calculation circuit 150, and color correction circuit 160 are logic circuits that process digital signals. The light source control circuit 130, brightness analysis circuit 140, brightness information calculation circuit 150, and color correction circuit 160 can each be constructed from logic circuits individually, or part 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 light source control circuit 130, brightness analysis circuit 140, brightness information calculation circuit 150, and color correction circuit 160 through a processor such as a DSP.

[0044] Alternatively, the circuit device 100 may also include a distortion correction circuit. The distortion correction circuit corrects image distortion caused by an optical system projecting an image displayed on the display panel 220 onto a screen, or by distortion caused by the screen itself. Specifically, the distortion correction circuit performs image correction on the image data IMA received by the interface circuit 110 to eliminate or reduce the aforementioned image distortion, and outputs the corrected image data to the brightness analysis circuit 140, the brightness information calculation circuit 150, and the color correction circuit 160. However, the distortion correction circuit may also be provided in the processing device 300 instead of the circuit device 100.

[0045] 2. Processing flow of the brightness information calculation circuit

[0046] Figure 3 This is a flowchart of the processing performed by the brightness information calculation circuit. Hereinafter, the object pixel is the pixel from which the brightness information is obtained.

[0047] In step S1, the coordinate analysis unit 151 determines the light source element used for brightness calculation based on the coordinates of the object pixel. For example, as in Figure 11 As will be described later, the coordinate analysis unit 151 determines a predetermined number of light source elements arranged around the object pixel as light source elements for brightness calculation.

[0048] In step S2, the coordinate analysis unit 151, for each light source element determined in step S1, determines the lookup table to be referenced and its rotation angle based on the position of that light source element. For example, as in Figures 4 to 10 As will be described later, the coordinate analysis unit 151 determines which of the lookup tables LUTA, LUTB, and LUTC to refer to and which of the rotation angles to set to 0°, 90°, 180°, and 270°.

[0049] In step S3, the brightness calculation unit 152 obtains the attenuation rate based on the distance between the coordinates of the target pixel and the light source element, referring to the lookup table determined in step S2, and performs linear interpolation on the attenuation rate to calculate the attenuation rate at the target pixel. Specifically, as in Figure 13 and Figure 14 As will be described later, the brightness calculation unit 152 obtains four attenuation rates near the aforementioned distance from the lookup table and performs linear interpolation based on these four attenuation rates.

[0050] In step S4, the brightness calculation unit 152 calculates the brightness of the light reaching the target pixel from the light source element based on the luminance of each light source element after dimming by the light source brightness determination unit 142 and the attenuation rate determined in step S3. Steps S2 to S4 are performed on all light source elements determined in step S1.

[0051] In step S5, the brightness calculation unit 152 calculates the brightness of the light reaching the target pixel from the backlight 210 by adding the brightness values ​​obtained in step S4 for all determined light source elements. For example, the brightness calculation example will be described later using the following formula (1), in which four terms on the right-hand side are added. Each calculated term corresponds to step S4, and the addition of the four terms corresponds to step S5.

[0052] 3. Details of step S2

[0053] The following is a detailed explanation of each step. First, use... Figures 4 to 10 The details of step S2 are explained below.

[0054] Figure 4 This is a graph illustrating the differences in attenuation rate distribution corresponding to the position of the light source element. Figure 4 The attenuation rate distribution is schematically shown in a manner that indicates symmetry, but does not represent an accurate attenuation rate distribution.

[0055] exist Figure 4 In this design, three mutually orthogonal directions are designated as the x-direction, y-direction, and z-direction. The backlight 210 and display panel 220 are arranged parallel to the xy-plane, with the backlight 210 positioned on the z-direction side of the display panel 220. The x-direction is the horizontal direction of the display panel 220, and the y-direction is the vertical direction of the display panel 220. Furthermore, an example is shown here where multiple light source elements 10 are arranged squarely on the backlight 210.

[0056] EDA to EDD are the four edges of the display panel 220. Edges EDA and EDC are opposite each other, and edges EDB and EDD are opposite each other. Furthermore, the edges of the display panel 220 can be referred to as the edges of the backlight 210. CNA is the corner where edges EDA and EDB intersect, CNB is the corner where edges EDB and EDC intersect, CNC is the corner where edges EDC and EDB intersect, and CND is the corner where edges EDD and EDA intersect. The corners CNA to CND are also referred to as corners or vertices. Furthermore, the corners of the display panel 220 can be referred to as the corners of the backlight 210.

[0057] The attenuation rate distribution (DFPA) of light source elements located away from the edges and corners is an isotropic distribution. That is, the attenuation rate distribution (DFPA) becomes a rotationally symmetric distribution centered on the light source element, meaning that the attenuation characteristics are direction-independent centered on the light source element. "Away from the edges and corners" means that in a square configuration, the light source element is located at least one row or column away from the edges and corners.

[0058] The attenuation rate distribution DFPB of a light source element positioned along edge EDA and away from corners CNA and CND is an isotropic distribution. Edge EDA is parallel to the y-direction. In this case, the attenuation rate distribution DFPB is linearly symmetric about a line passing through the center of DFPB and parallel to the x-direction, and non-linearly symmetric about a line passing through the center of DFPB and parallel to the y-direction.

[0059] The attenuation rate distribution (DFPC) of the light source element configured in the corner CNC is an isotropic distribution. The attenuation rate distribution (DFPC) is non-linearly symmetric about a line passing through the center of the attenuation rate distribution (DFPB) and parallel to the x-direction, and also non-linearly symmetric about a line passing through the center of the attenuation rate distribution (DFPB) and parallel to the y-direction.

[0060] Figure 5 This is a diagram illustrating the attenuation rate distribution of anisotropy. The display device 200 includes a backlight 210 and a structure 270 disposed around the display panel 220. The structure 270 is, for example, a light-shielding member that houses the backlight 210 and the display panel 220 and provides light shielding so that light from the backlight 210 to the display panel 220 does not leak to the outside. A portion of the light emitted from the light source element 10 near the edge or corner of the backlight 210 is reflected by the structure 270, and the reflected light reaches the display panel 220. In these areas AR1 and AR2, the direct light from the light source element 10 overlaps with the reflected light from the structure 270, thus increasing the amount of light compared to the case without reflection. This results in… Figure 4 The attenuation rate distribution is anisotropic, similar to that of DFPB and DFPC.

[0061] Figure 6This is an example of a lookup table LUTA corresponding to light source elements far from edges and corners. u is the distance between the light source element and the object pixel in the x-direction. v is the distance between the light source element and the object pixel in the y-direction. The following shows the input of the lookup table as u. 2 and v 2 Examples are given, but the input to the lookup table is not limited to this; for example, it can also be u and v.

[0062] u = v = 0 is the center of the attenuation rate distribution. The direction DA, where u increases from the center, corresponds to the direction from the center towards edge EDA. The direction DC, where u decreases from the center, corresponds to the direction from the center towards edge EDC. The direction DD, where v increases from the center, corresponds to the direction from the center towards edge EDD. The direction DB, where v decreases from the center, corresponds to the direction from the center towards edge EDB. In the lookup table LUTA, the attenuation characteristics are the same in all directions from the center towards any edge. That is, the attenuation rate distribution of the lookup table LUTA is rotationally symmetric about its center.

[0063] Figure 7 This is an example of a lookup table (LUTB) corresponding to light source elements arranged along the edges. Figure 7 In the image, shaded areas represent the parts of lookup tables LUTB and LUTA that differ from each other.

[0064] In the lookup table LUTB, the attenuation characteristics along direction DA from the center to edge EDA differ from those along directions DB, DC, and DD from the center to edges EDB, EDC, and EDD. The attenuation characteristics along directions DB, DC, and DD from the center to edges EDB, EDC, and EDD are identical. That is, the attenuation rate distribution of the lookup table LUTB is non-rotationally symmetric about its center. Furthermore, the attenuation rate distribution of the lookup table LUTB is linearly symmetric about a line passing through its center and parallel to direction DA, but non-linearly symmetric about a line passing through its center and parallel to direction DD.

[0065] Figure 8 This is an example of a lookup table (LUTC) corresponding to light source elements positioned at the corners. Figure 8 In the image, shaded areas represent the parts of lookup tables LUTC and LUTA that are different.

[0066] In the lookup table LUTC, the attenuation characteristics along the direction DD from the center towards edge EDD differ from those along the direction DB from the center towards edge EDB. Similarly, the attenuation characteristics along the direction DC from the center towards edge EC differ from those along the direction DA from the center towards edge EDA. The attenuation characteristics along the directions DC and DD from the center towards edges EDC and EDD are identical, as are the attenuation characteristics along the directions DA and DB from the center towards edges EDA and EDB. That is, the attenuation rate distribution of the lookup table LUTC is non-rotationally symmetric about its center. Furthermore, the attenuation rate distribution of the lookup table LUTC is non-linearly symmetric about a line passing through its center and parallel to direction DC, and also non-linearly symmetric about a line passing through its center and parallel to direction DD.

[0067] Figure 9 This is a diagram illustrating the rotation of the lookup table LUTB corresponding to the light source elements arranged along the edges.

[0068] like Figure 9 As shown, the attenuation rate distribution of the light source elements arranged along edges EDB, EDC, and EDD is the distribution after rotating the attenuation rate distribution DFPB of the light source elements arranged along edge EDA counterclockwise by 90°, 180°, and 270°. The coordinate analysis unit 151 determines the reference lookup table and its rotation angle as follows.

[0069] The coordinate analysis unit 151 determines the lookup table LUTB as the reference lookup table for the light source element arranged along edge EDA, and determines the rotation angle to be 0°. Similarly, the coordinate analysis unit 151 determines the lookup table LUTB as the reference lookup table for the light source elements arranged along edges EDB, EDC, and EDD, and determines the rotation angle to be 90°, 180°, and 270°, respectively. The brightness calculation unit 152 calculates the attenuation rate of the target pixel by referring to the reference lookup table after rotating counterclockwise with the above-determined rotation angle.

[0070] Figure 10 This is a diagram illustrating the rotation of the lookup table LUTC corresponding to the light source elements located at the corners.

[0071] like Figure 10 As shown, the attenuation rate distribution of the light source elements arranged at corners CND, CNA, and CNB is the distribution after rotating the attenuation rate distribution DFPC of the light source element arranged at corner CNC counterclockwise by 90°, 180°, and 270°. Based on this, the coordinate analysis unit 151 determines the reference lookup table and its rotation angle as follows.

[0072] The coordinate analysis unit 151 determines the lookup table as LUTC for the light source elements positioned at the corner CNC and sets the rotation angle to 0°. Similarly, the coordinate analysis unit 151 determines the lookup table as LUTC for the light source elements positioned at the corners CND, CNA, and CNB, and sets the rotation angles to 90°, 180°, and 270°, respectively. The brightness calculation unit 152 calculates the attenuation rate of the target pixel by referring to the lookup table rotated counterclockwise with the aforementioned rotation angles.

[0073] In addition, Figure 9 and Figure 10 The example shown illustrates rotating the lookup table counterclockwise, but it is also possible to rotate it clockwise. Clockwise rotation angles of 0°, 90°, 180°, and 270° correspond to counterclockwise rotation angles of 0°, 270°, 180°, and 90°, respectively.

[0074] In this embodiment described above, the circuit device 100 includes: a storage unit 170 storing a plurality of lookup tables; and a brightness information calculation circuit 150 calculating brightness information representing the brightness of light reaching an object pixel from the backlight 210 to the display panel 220. Each lookup table in the plurality of lookup tables represents the attenuation rate distribution of the light source element of the backlight 210 of the display device 200 having the display panel 220 and the backlight 210. The storage unit 170 stores a first lookup table and a second lookup table. The first lookup table corresponds to a first light source element disposed at a first position in the backlight 210 and represents the first attenuation rate distribution of the first light source element. The second lookup table corresponds to a second light source element disposed at a second position in the backlight 210 different from the first position and represents the second attenuation rate distribution of the second light source element. The brightness information calculation circuit 150 calculates the first attenuation rate of light reaching the object pixel from the first light source element based on the first lookup table, and calculates the second attenuation rate of light reaching the object pixel from the second light source element based on the second lookup table. The luminance information calculation circuit 150 calculates luminance information based on the first attenuation rate and the second attenuation rate.

[0075] Furthermore, the first lookup table here can be any lookup table from LUTA, LUTB, and LUTC. The second lookup table here can be any lookup table from LUTA, LUTB, and LUTC that is different from the first lookup table.

[0076] According to this embodiment, the first lookup table corresponds to the first light source element located at the first position, and the second lookup table corresponds to the second light source element located at a second position different from the first position. Therefore, lookup tables with different attenuation rate distributions can be applied according to the position of the light source element. Thus, the brightness of the light reaching each pixel from the backlight can be accurately determined, taking into account the differences in light diffusion patterns corresponding to the positions of the light source elements. Since the brightness of the light reaching each pixel from the backlight can be accurately determined, appropriate color correction of the image data can be performed.

[0077] Furthermore, in this embodiment, each lookup table is a table that corresponds to the attenuation rate at the distance from the light source element to the pixel of the display panel 220. The brightness information calculation circuit 150 calculates the first attenuation rate at the distance from the first light source element to the target pixel based on the first lookup table. The brightness information calculation circuit 150 calculates the second attenuation rate at the distance from the second light source element to the target pixel based on the second lookup table.

[0078] exist Figures 6-8 In the example, the distance from the light source element to the object pixel is the square of the horizontal distance u and the square of the vertical distance v, but it is not limited to this. For example, the distance from the light source element to the object pixel can be the horizontal distance u and the vertical distance v, or it can be the straight-line distance from the light source element to the object pixel and the angle between that straight line and a reference direction. The reference direction is, for example, the x-direction or the y-direction.

[0079] According to this embodiment, a first attenuation rate at the distance from the first light source element to the target pixel is obtained based on a first lookup table, and a second attenuation rate at the distance from the second light source element to the target pixel is obtained based on a second lookup table. Therefore, the attenuation rate at the distance from the light source element to the target pixel can be obtained based on lookup tables with different attenuation rate distributions according to the position of the light source element.

[0080] In addition, in this embodiment, the second position is the position closer to the first side of the display panel 220 than the first position.

[0081] The first position here is with Figure 4 The attenuation rate distribution of DFPA corresponds to the position of the light source element far from the edges and corners. The second position here is related to... Figure 4 The attenuation rate distribution DFPB corresponds to the position of the light source element arranged along the edge and away from the corner. That is, the first lookup table here is LUTA, and the second lookup table is LUTB. Furthermore, the first edge is in... Figure 4 The middle edge is EDA, but it is not limited to this; it can also be any of the four edges of the display panel 220.

[0082] like Figure 5As explained, the attenuation rate distribution of the light source element located near the edge of the display panel 220 is affected by reflected light from the surrounding structure 270, and therefore differs from the attenuation rate distribution of the light source element located away from the edge of the display panel 220. According to this embodiment, the brightness of the light reaching each pixel from the backlight can be accurately determined by taking into account such differences in attenuation rate distribution.

[0083] In this embodiment, the backlight 210 includes a third light source element. The third light source element is positioned at a third position, closer to the first position than the first position, on the third side of the display panel 220 opposite to the first side. The brightness information calculation circuit 150 calculates a third attenuation rate of light reaching the target pixel from the third light source element based on a lookup table after rotating the second lookup table by 180 degrees. The brightness information calculation circuit 150 calculates brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

[0084] The third side here is Figure 4 and Figure 9 The middle position is the edge EDC opposite to edge EDA. The third position here refers to the location of the light source element at the corners of edge EDC, positioned away from both ends of edge EDC. For example... Figure 9 As explained, by rotating the lookup table LUTB of the light source elements arranged along edge EDA by 180 degrees, a lookup table of the light source elements arranged along edge EDC is obtained.

[0085] According to this embodiment, a lookup table of light source elements disposed near one edge is stored in the storage unit 170. By rotating this lookup table, lookup tables disposed near the other three edges can be generated. This saves storage capacity in the storage unit 170. However, it is also possible to store lookup tables of light source elements disposed near each of the four edges in the storage unit 170.

[0086] Alternatively, in this embodiment, the second position may also be the position closer to the first corner where the first and second sides of the display panel 220 intersect, compared to the first position.

[0087] The first position here is with Figure 4 The attenuation rate distribution DFPA corresponds to the positions of the light source elements farthest from the edges and corners. Here, the first edge is edge EDC, the second edge is edge EDD, and the second position is... Figure 4 The attenuation rate distribution of the DFPC corresponds to the position of the light source element in the corner CNC. That is, the first lookup table here is LUTA, and the second lookup table is LUTC. Additionally, the first corner is in... Figure 4 The center is a corner CNC part, but it is not limited to this; it can also be any of the four corners of the display panel 220.

[0088] like Figure 5 As explained, the attenuation rate distribution of the light source element located near the corner of the display panel 220 is affected by reflected light from the surrounding structure 270, and therefore differs from the attenuation rate distribution of the light source element located away from the corner of the display panel 220. According to this embodiment, the brightness of the light reaching each pixel from the backlight can be accurately determined by taking into account such differences in attenuation rate distribution.

[0089] In this embodiment, the backlight 210 includes a third light source element. The third light source element is positioned closer to the second corner of the display panel 220 than the first position, at the intersection of the third side opposite the first side and the fourth side opposite the second side. The brightness information calculation circuit 150 calculates a third attenuation rate of light reaching the target pixel from the third light source element based on a lookup table after rotating the second lookup table by 180 degrees. The brightness information calculation circuit 150 calculates brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

[0090] The third side here is Figure 4 and Figure 10 The fourth edge is EDA, which is opposite to edge EDC; the fifth edge is EDB, which is opposite to edge EDD; and the sixth position is the location of the light source element positioned at the corner CNA. For example... Figure 10 As explained, by rotating the lookup table LUTC of the light source element located in the corner CNC by 180 degrees, the lookup table of the light source element located in the corner CNA can be obtained.

[0091] According to this embodiment, a lookup table of light source elements disposed near one corner is stored in the storage unit 170. By rotating this lookup table, lookup tables disposed near the other three corners can be generated. This saves storage capacity in the storage unit 170. However, it is also possible to store lookup tables of light source elements disposed near each of the four corners in the storage unit 170.

[0092] Furthermore, in this embodiment, the first attenuation rate distribution is a rotationally symmetric attenuation rate distribution about the center. The second attenuation rate distribution is a non-rotationally symmetric attenuation rate distribution about the center.

[0093] In addition, the first attenuation rate distribution here is similar to Figure 4 The attenuation rate distribution DFPA corresponds to this. The second attenuation rate distribution here can be... Figure 4 The attenuation rate distribution can be any attenuation rate distribution in DFPB and DFPC.

[0094] The attenuation rate distribution of a light source element positioned away from the edges or corners of the display panel 220 is less affected by reflected light from the structures 270 surrounding the backlight 210 or the display panel 220. Therefore, the attenuation rate distribution of this light source is rotationally symmetric, or can be approximated as rotationally symmetric. On the other hand, the attenuation rate distribution of a light source element positioned close to the edges or corners of the display panel 220 is affected by reflected light from the structures 270 surrounding it. Therefore, the attenuation rate distribution of this light source is non-rotationally symmetric, or can be approximated as non-rotationally symmetric.

[0095] Furthermore, in this embodiment, the attenuation characteristics of the second attenuation rate distribution along one side of the display panel 220 from the center are different from the attenuation characteristics along a side of the display panel 220 that is different from the one side.

[0096] For example, the second attenuation rate distribution is Figure 4 In the attenuation rate distribution DFPB, "one edge" is edge EDA, and "edges different from one edge" are any of the edges EDB, EDC, and EDD. Alternatively, in the second attenuation rate distribution... Figure 4 When the attenuation rate distribution is DFPC, "1 edge" is any edge between edges EDC and EDD, and "edge different from 1 edge" is any edge between edges EDA and EDB.

[0097] Reflected light from structures 270 disposed around the backlight 210 or display panel 220 affects regions near the edges in the attenuation rate distribution. Therefore, the attenuation characteristics in the direction toward the edge unaffected by reflected light from the structures 270 are different from the attenuation characteristics in the direction toward the edge affected by reflected light from the structures 270.

[0098] In this embodiment, the storage unit 170 stores a third lookup table. The third lookup table corresponds to a third light source element located at a third position on the backlight 210, different from the first and second positions, and represents the third attenuation rate distribution of the third light source element. The second position is the position closer to the first edge of the display panel 220 compared to the first position. The third position is the position closer to the first corner where the second and third edges of the display panel intersect compared to the first position. The brightness information calculation circuit 150 calculates the third attenuation rate of light reaching the target pixel from the third light source element based on the third lookup table, and calculates brightness information based on the first, second, and third attenuation rates.

[0099] The first position here is with Figure 4 The attenuation rate distribution of DFPA corresponds to the position of the light source element far from the edges and corners. The second position here is related to... Figure 4 The attenuation rate distribution DFPB corresponds to the position of the light source element arranged along the edge and away from the corner. The third position here is related to... Figure 4 The attenuation rate distribution of the DFPC corresponds to the position of the light source element configured in the corner CNC. The first side, the second side, and the third side correspond to sides EDA, EDC, and EDD, respectively, and the first corner corresponds to the corner CNC. However, the first side can be any side among sides EDA to EDD, and the first corner can be any corner among corners CNA to CND.

[0100] According to this embodiment, the first to third lookup tables correspond to the first to third light source elements located at different first to third positions. Therefore, lookup tables with different attenuation rate distributions can be applied according to the position of the light source element, thus allowing for accurate determination of the brightness of light reaching each pixel from the backlight, taking into account the differences in light diffusion patterns corresponding to the position of the light source element.

[0101] In this embodiment, the circuit device 100 includes a brightness analysis circuit 140 and a color correction circuit 160. The brightness analysis circuit 140 performs brightness analysis on the image data IMA and, based on the results of this analysis, calculates dimming information for local dimming control. The brightness information calculation circuit 150 calculates the first brightness of light reaching the target pixel from the first light source element based on the dimming information and a first attenuation rate, and calculates the second brightness of light reaching the target pixel from the second light source element based on the dimming information and a second attenuation rate. The brightness information calculation circuit 150 calculates brightness information representing the brightness of light reaching the target pixel from the backlight 210 based on the first and second brightness. The color correction circuit 160 performs color correction on the image data of the target pixel based on the brightness information and outputs the color-corrected image data IMA to the display device 200.

[0102] According to this embodiment, considering the difference in light diffusion patterns corresponding to the positions of the light source elements, the first brightness of the light reaching the target pixel from the first light source element and the second brightness of the light reaching the target pixel from the second light source element are accurately determined. Thus, brightness information representing the brightness of the light reaching the target pixel from the backlight 210 is accurately determined, and therefore the color correction circuit 160 can appropriately perform color correction on the image data of the target pixel based on the brightness information.

[0103] 4. Details of steps S1, S4, and S5

[0104] use Figure 11 and Figure 12 The details of steps S1, S4, and S5 are explained. Figure 11 This is an explanatory diagram illustrating the method for determining the light source element used in brightness calculation.

[0105] The brightness information calculation circuit 150 sets the pixel from which the brightness information is to be obtained as the target pixel 20 and sets its xy coordinates as (xP, yP). The brightness information calculation circuit 150 calculates the brightness information of each pixel of the display panel 220 by sequentially shifting the target pixels 20.

[0106] The xy coordinates of the light source element 10 are set to (xL, yL). When viewing the display panel 220 and the backlight 210 from above in the z-direction, the coordinates on the display panel 220 corresponding to the reference points of each light source element are (xL, yL). The reference point is the center of the light source element or the point of highest brightness when viewed from above.

[0107] The coordinate analysis unit 151 selects a plurality of light source elements 10 arranged around the object pixel 20. The selected plurality of light source elements 10 are referred to as the light source element group 15. Figure 11 This example shows four light source elements selected around the object pixel 20. However, any number of light source elements can be selected around the object pixel 20, or all light source elements of the backlight 210 can be selected.

[0108] Figure 12 This is a diagram illustrating the distances between object pixels and the light source elements in the light source element group. The light source element in the i-th row and j-th column of the 2×2 light source element group 15 is denoted as LDij. The x and y coordinates of light source element LDij are represented as (xLj, yLi). i and j are integers greater than 1 and less than 2.

[0109] The distance is a distance on the xy plane or on the display panel 220. The distance can be an actual distance such as a meter, or it can be a distance specified in a defined unit. For example, when the specified unit is the pixel pitch of the display panel 220, the distance is expressed in terms of the number of pixels on the display panel 220.

[0110] The coordinate analysis unit 151 calculates the distances u1 and u2 between the light source element and the object pixel 20 in the x-direction and the distances v1 and v2 between the light source element and the object pixel 20 in the y-direction. uj is the distance between the light source element in the j-th column in the horizontal direction and the object pixel 20. Specifically, uj = xLj - xP. vi is the distance between the light source element in the i-th row in the vertical direction and the object pixel 20. Specifically, vi = yLi - yP.

[0111] The brightness calculation unit 152 calculates the brightness PIX_BL of the light reaching the target pixel 20 from the plurality of light source elements belonging to the light source element group 15 using the following formula (1). LED_BLij is the luminous brightness of the light source element LDij determined by the light source brightness determination unit 142. LUT_LDij(uj2, vi 2) is the attenuation rate of light from the light source element LDij to the target pixel 20, which is the attenuation rate calculated by linear interpolation in step S3.

[0112] PIX_BL=LED_BL11×LUT_LD11(u1 2 v1 2 )+LED_BL12×LUT_LD12(u2 2 v1 2 )+LED_BL21×LUT_LD21(u1 2 v2 2 )+LED_BL22×LUT_LD22(u2 2 v2 2 )···(1)

[0113] 5. Details of step S3

[0114] use Figure 13 and Figure 14 The details of step S3 will be explained below. Figure 13 This diagram illustrates the calculation method for linear interpolation. Here, the brightness of light reaching the target pixel 20 from light source element LD22 is used as an example, but the same applies to the brightness of light reaching the target pixel 20 from light source elements LD11, LD12, and LD21. Hereinafter, the case where the distance in the x-direction is u and the distance in the y-direction is v will be denoted as (u, v).

[0115] The distance between the light source element LD22 and the target pixel 20 is (u2, v2). The brightness calculation unit 152 selects the four nearest points (ua, va), (ub, va), (ua, vb), and (ub, vb) within the discrete distance used in the lookup table, and obtains their attenuation rates Luava, Lubva, Luavb, and Lubvb. The brightness calculation unit 152 performs linear interpolation in the horizontal direction using the following equation (2), and uses the result to perform linear interpolation in the vertical direction using the following equation (3). The result of this linear interpolation is the attenuation rate LUT_LD22(u2) of the light from the light source element LD22 to the target pixel 20. 2 v2 2 ).

[0116]

[0117]

[0118]

[0119] In equation (2) above, the denominator of the first term on the right is ub. 2 -ua2 When n is an integer greater than or equal to 1, by using ub 2 -ua 2 =2 n This distance is used for lookup tables, where fractional operations become bit shifts towards the LSB, reducing the computational load. For example, in Figures 6-8 In the lookup table, using u 2 =0, 32, 64, 96, 128, ub 2 -ua 2 =32=2 5 The same applies to the fractional part of the first term on the right side of equation (3) above.

[0120] Figure 14 This is a diagram illustrating a specific calculation example of linear interpolation. Here, we will explain an example where the lookup table LUTA is applied to the light source element LD22, and (u2, v2) = (5, 7).

[0121] (u2, v2) = (5, 7) means u2>0, v2>0 and (u2 2 v2 2 ) = (25, 49). In the lookup table LUTA, the four points containing this point are (ua) among u>0 and v>0. 2 va 2 ) = (0, 32), (ub 2 va 2 ) = (32, 32), (ua 2 ,vb 2 ) = (0, 64), (ub 2 ,vb 2 = (32, 64). The attenuation rates at these points are Luava = 0.8, Lubva = 0.717, Luavb = 0.6, and Lubvb = 0.51. By substituting them into equations (2) and (3) above, the linear interpolation operation becomes equation (4).

[0122]

[0123]

[0124]

[0125] The circuit arrangement of this embodiment described above includes: a storage unit that stores multiple lookup tables; and a brightness information calculation circuit that calculates brightness information. Each lookup table in the multiple lookup tables represents the attenuation rate distribution of the light source element of the backlight of the display device having a display panel and a backlight. The brightness information represents the brightness of light reaching the target pixel from the backlight. The storage unit stores a first lookup table and a second lookup table as multiple lookup tables. The first lookup table corresponds to a first light source element disposed at a first position in the backlight and represents the first attenuation rate distribution of the first light source element. The second lookup table corresponds to a second light source element disposed at a second position in the backlight that is different from the first position and represents the second attenuation rate distribution of the second light source element. The brightness information calculation circuit calculates the first attenuation rate of light reaching the target pixel from the first light source element based on the first lookup table, and calculates the second attenuation rate of light reaching the target pixel from the second light source element based on the second lookup table. The brightness information calculation circuit calculates the brightness information based on the first attenuation rate and the second attenuation rate.

[0126] According to this embodiment, the first lookup table corresponds to the first light source element located at the first position, and the second lookup table corresponds to the second light source element located at a second position different from the first position. Therefore, lookup tables with different attenuation rate distributions can be applied according to the position of the light source element. Thus, the difference in light diffusion patterns corresponding to the position of the light source element can be taken into account, and the brightness of the light reaching each pixel from the backlight can be accurately determined. Since the brightness of the light reaching each pixel from the backlight can be accurately determined, appropriate color correction of the image data can be performed.

[0127] In this embodiment, each lookup table can also be a table that corresponds to the attenuation rate at the distance from the light source element to the pixel of the display panel. The brightness information calculation circuit can also calculate the first attenuation rate at the distance from the first light source element to the target pixel based on the first lookup table. The brightness information calculation circuit can also calculate the second attenuation rate at the distance from the second light source element to the target pixel based on the second lookup table.

[0128] According to this embodiment, a first attenuation rate at the distance from the first light source element to the target pixel is obtained based on a first lookup table, and a second attenuation rate at the distance from the second light source element to the target pixel is obtained based on a second lookup table. Therefore, the attenuation rate at the distance from the light source element to the target pixel can be obtained based on lookup tables with different attenuation rate distributions according to the position of the light source element.

[0129] Alternatively, in this embodiment, the second position may be a position closer to the first side of the display panel than the first position.

[0130] Because the attenuation rate distribution of light source elements located near the edge of the display panel is affected by reflected light from structures disposed around them, it differs from that of light source elements located away from the edge of the display panel. According to this embodiment, this difference in attenuation rate distribution can be taken into account, allowing for accurate determination of the brightness of light reaching each pixel from the backlight.

[0131] Alternatively, in this embodiment, the backlight may also include a third light source element located at a third position on the third side opposite to the first side, closer to the display panel than the first position. The brightness information calculation circuit may also calculate a third attenuation rate of light reaching the target pixel from the third light source element based on a lookup table after rotating the second lookup table by 180 degrees. The brightness information calculation circuit may also calculate brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

[0132] According to this embodiment, a lookup table of light source elements arranged near one edge is stored in the storage unit. By rotating this lookup table, lookup tables arranged near the other three edges can be generated. This saves storage capacity in the storage unit.

[0133] Alternatively, in this embodiment, the second position may also be a position closer to the first corner where the first and second sides of the display panel intersect, which is closer than the first position.

[0134] The attenuation rate distribution of a light source element located near the corner of the display panel is affected by reflected light from structures surrounding it, and therefore differs from that of a light source element located away from the corner of the display panel. According to this embodiment, this difference in attenuation rate distribution can be taken into account, allowing for accurate determination of the brightness of the light reaching each pixel from the backlight.

[0135] In this embodiment, the backlight may also include a third light source element. The third light source element may also be located at a third position, closer to the third side of the display panel opposite the first side and the fourth side opposite the second side, at the second corner. The brightness information calculation circuit may also calculate the third attenuation rate of light reaching the target pixel from the third light source element based on a lookup table after rotating the second lookup table by 180 degrees. The brightness information calculation circuit may also calculate brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

[0136] According to this embodiment, a lookup table of light source elements located near one corner is stored in the storage unit. By rotating this lookup table, lookup tables located near the other three corners can be generated. This saves storage capacity in the storage unit.

[0137] Alternatively, in this embodiment, the first attenuation rate distribution may also be a rotationally symmetric attenuation rate distribution about the center. The second attenuation rate distribution may also be a non-rotationally symmetric attenuation rate distribution about the center.

[0138] The attenuation rate distribution of a light source element positioned away from the edges or corners of the display panel is less affected by reflected light from structures surrounding the backlight or display panel. Therefore, the attenuation rate distribution of this light source is rotationally symmetric or can be approximated as rotationally symmetric. On the other hand, the attenuation rate distribution of a light source element positioned close to the edges or corners of the display panel is affected by reflected light from structures surrounding it. Therefore, the attenuation rate distribution of this light source is non-rotationally symmetric or can be approximated as non-rotationally symmetric.

[0139] In addition, in this embodiment, the second attenuation rate distribution may also be different in terms of the attenuation characteristics in the direction from the center toward one side of the display panel and the attenuation characteristics in the direction from the center toward a side different from the one side of the display panel.

[0140] Reflected light from structures surrounding the backlight or display panel affects the region near the edge in the attenuation rate distribution. Therefore, the attenuation characteristics in the direction towards the edge unaffected by reflected light from the structure differ from those in the direction towards the edge affected by reflected light from the structure.

[0141] In this embodiment, the storage unit may also store a third lookup table as multiple lookup tables. The third lookup table may correspond to a third light source element located at a third position different from the first and second positions on the backlight, representing the third attenuation rate distribution of the third light source element. The second position may be a position closer to the first edge of the display panel than the first position. The third position may be a position closer to the first corner where the second and third edges of the display panel intersect, compared to the first position. The brightness information calculation circuit may also calculate the third attenuation rate of light reaching the target pixel from the third light source element based on the third lookup table, and calculate brightness information based on the first, second, and third attenuation rates.

[0142] According to this embodiment, the first to third lookup tables correspond to the first to third light source elements located at different first to third positions. Therefore, lookup tables with different attenuation rate distributions can be applied according to the position of the light source element, thus allowing for accurate determination of the brightness of light reaching each pixel from the backlight, taking into account the differences in light diffusion patterns corresponding to the position of the light source element.

[0143] Alternatively, the circuit apparatus of this embodiment may also include a brightness analysis circuit and a color correction circuit. The brightness analysis circuit may perform brightness analysis on the image data and, based on the results of the brightness analysis, determine the dimming information in local dimming control. Alternatively, the brightness information calculation circuit may determine the first brightness of the light reaching the target pixel from the first light source element based on the dimming information and a first attenuation rate, determine the second brightness of the light reaching the target pixel from the second light source element based on the dimming information and a second attenuation rate, and calculate the brightness information based on the first and second brightness. The color correction circuit may also perform color correction on the image data of the target pixel based on the brightness information and output the color-corrected image data to the display device.

[0144] According to this embodiment, considering the difference in light diffusion patterns corresponding to the positions of the light source elements, the first brightness of the light reaching the target pixel from the first light source element and the second brightness of the light reaching the target pixel from the second light source element are accurately determined. Thus, brightness information representing the brightness of the light reaching the target pixel from the backlight is accurately determined, and therefore the color correction circuit can appropriately perform color correction on the image data of the target pixel based on the brightness information.

[0145] In addition, the display system of this embodiment includes any of the circuit devices and display devices described above.

[0146] 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 novel 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, characterized in that, The circuit device includes: The storage unit stores multiple lookup tables, each lookup table showing the attenuation rate distribution of the light source element of the backlight of the display device having a display panel and a backlight; as well as A brightness information calculation circuit calculates brightness information representing the brightness of light reaching the target pixels of the display panel from the backlight. The storage unit stores a first lookup table and a second lookup table as the plurality of lookup tables. The first lookup table corresponds to a first light source element located at a first position in the backlight and represents the first attenuation rate distribution of the first light source element. The second lookup table corresponds to a second light source element located at a second position in the backlight, different from the first position, and represents the second attenuation rate distribution of the second light source element. The brightness information calculation circuit calculates the first attenuation rate of light from the first light source element to the target pixel based on the first lookup table, calculates the second attenuation rate of light from the second light source element to the target pixel based on the second lookup table, and calculates the brightness information based on the first attenuation rate and the second attenuation rate. The second position is the position closer to the first edge of the display panel compared to the first position. The backlight includes a third light source element disposed at a third position, which, compared to the first position, is closer to the third side of the display panel opposite the first side. The brightness information calculation circuit calculates the third attenuation rate of light from the third light source element to the object pixel based on the lookup table after rotating the second lookup table by 180 degrees, and calculates the brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

2. A circuit device, characterized in that, The circuit device includes: The storage unit stores multiple lookup tables, each lookup table showing the attenuation rate distribution of the light source element of the backlight of the display device having a display panel and a backlight; as well as A brightness information calculation circuit calculates brightness information representing the brightness of light reaching the target pixels of the display panel from the backlight. The storage unit stores a first lookup table and a second lookup table as the plurality of lookup tables. The first lookup table corresponds to a first light source element located at a first position in the backlight and represents the first attenuation rate distribution of the first light source element. The second lookup table corresponds to a second light source element located at a second position in the backlight, different from the first position, and represents the second attenuation rate distribution of the second light source element. The brightness information calculation circuit calculates the first attenuation rate of light from the first light source element to the target pixel based on the first lookup table, calculates the second attenuation rate of light from the second light source element to the target pixel based on the second lookup table, and calculates the brightness information based on the first attenuation rate and the second attenuation rate. The second position is the position closer to the first corner where the first and second sides of the display panel intersect, compared to the first position. The backlight includes a third light source element disposed at a third position, which, compared to the first position, is closer to the second corner of the display panel where the third side opposite the first side and the fourth side opposite the second side intersect. The brightness information calculation circuit calculates the third attenuation rate of light from the third light source element to the object pixel based on the lookup table after rotating the second lookup table by 180 degrees, and calculates the brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

3. The circuit device according to claim 1 or 2, characterized in that, Each lookup table is a table that corresponds to the attenuation rate at the distance from the light source element to the pixel of the display panel. The brightness information calculation circuit calculates the first attenuation rate at the distance from the first light source element to the object pixel based on the first lookup table, and calculates the second attenuation rate at the distance from the second light source element to the object pixel based on the second lookup table.

4. The circuit device according to claim 1 or 2, characterized in that, The first attenuation rate distribution is a rotationally symmetric attenuation rate distribution about the center. The second attenuation rate distribution is an attenuation rate distribution that is non-rotationally symmetric about the center.

5. The circuit device according to claim 4, characterized in that, The second attenuation rate distribution has different attenuation characteristics in the direction from the center toward one edge of the display panel and in the direction from the center toward a different edge of the display panel.

6. The circuit device according to claim 1 or 2, characterized in that, As one of the plurality of lookup tables, the storage unit also stores a third lookup table, which corresponds to a third light source element located at a third position different from the first and second positions of the backlight, and represents a third attenuation rate distribution of the third light source element. The second position is the position closer to the first edge of the display panel compared to the first position. The third position is the position closer to the first corner where the second and third sides of the display panel intersect, compared to the first position. The brightness information calculation circuit calculates the third attenuation rate of light from the third light source element to the object pixel based on the third lookup table, and calculates the brightness information based on the first attenuation rate, the second attenuation rate, and the third attenuation rate.

7. The circuit device according to claim 1 or 2, characterized in that, The circuit device includes a brightness analysis circuit and a color correction circuit. The brightness analysis circuit performs brightness analysis on the image data, and based on the results of the brightness analysis, determines the dimming information in the local dimming control of the backlight. The brightness information calculation circuit calculates the first brightness of the light reaching the target pixel from the first light source element based on the dimming information and the first attenuation rate, calculates the second brightness of the light reaching the target pixel from the second light source element based on the dimming information and the second attenuation rate, and calculates the brightness information based on the first brightness and the second brightness. The color correction circuit performs color correction on the image data of the object pixel based on the brightness information, and outputs the color-corrected image data to the display device.

8. A display system, characterized in that, The display system includes the circuitry as described in claim 1 or 2 and the display device.

Images