Circuit devices and display systems

Abstract

To provide a circuit device or the like that can reduce the processing load of lookup table interpolation. [Solution] The circuit device 100 includes a light source brightness determination circuit 140, an illumination brightness calculation circuit 150 that calculates illumination brightness data indicating the brightness of light reaching the target pixel from the light source in N columns and M rows, and a color correction circuit 160 that performs color correction of the image data of the target pixel based on the illumination brightness data. The illumination brightness calculation circuit 150 calculates the first one-dimensional lookup table to the Mth one-dimensional lookup table by interpolating the attenuation rate of the two-dimensional lookup table 175 in the vertical direction for the first vertical distance to the Mth vertical distance, which is the vertical distance between the target line containing the target pixel and each row light source in the M rows. The illumination brightness calculation circuit 150 calculates the illumination brightness data based on the first one-dimensional lookup table to the Mth one-dimensional lookup table, the first horizontal distance to the Nth horizontal distance, which is the horizontal distance between the target pixel and each column light source in the N columns, and the light source brightness data.

Description

Technical Field

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

[0002] Patent Document 1 discloses a circuit device that performs local dimming control for a display device. The circuit device includes a brightness information calculation circuit, and the brightness information calculation circuit calculates brightness information indicating the brightness of light reaching a target pixel from n×m light source elements based on dimming information of the n×m light source elements. The n×m light source elements are light source elements arranged around the target pixel for color correction in local dimming control among the plurality of light source elements of a backlight. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2024-9483 Summary of the Invention Problems to be Solved by the Invention

[0004] In Patent Document 1, n×m attenuation factors corresponding to the n×m light source elements are obtained based on the distance between each light source element and the target pixel, and the brightness of light reaching the target pixel from the n×m light source elements is obtained by the sum of products of the emission brightness of the light source elements and the attenuation factors. Although the amount of calculation is reduced by limiting to the surrounding n×m light source elements, further reduction in processing load is desired. Means for Solving the Problems

[0005] One aspect of the present disclosure is a circuit device for local dimming control of a display device including a backlight having a plurality of light sources arranged in two dimensions and a display panel, comprising: a light source brightness determination circuit that outputs light source brightness data indicating the luminous brightness of each light source of the backlight based on image data; an illumination brightness calculation circuit that calculates illumination brightness data indicating the brightness of light reaching the target pixel from N columns and M rows of light sources (N is an integer of 2 or more, M is an integer of 2 or more) around the target pixel of the display panel based on a two-dimensional lookup table showing the attenuation rate distribution of the light sources and the light source brightness data; and a circuit device for color correction of the image data of the target pixel based on the illumination brightness data. The circuit device includes a color correction circuit that performs color correction and outputs the color-corrected image data to the display device, wherein the illumination brightness calculation circuit obtains a first one-dimensional lookup table to

[0006] Another aspect of this disclosure relates to a display system including the above-described circuit device and the display device. [Brief explanation of the drawing]

[0007] [Figure 1] An example configuration of electronic equipment including a display system. [Figure 2] Detailed configuration example of a circuit device. [Figure 3] An example of an N-column, M-row arrangement of light sources used in calculating illumination luminance data. [Figure 4] An example of a 2D lookup table. [Figure 5] A diagram illustrating a method for determining the attenuation rate from a 2D lookup table. [Figure 6] A first flowchart example illustrating the interpolation procedure. [Figure 7] Detailed diagram of Step S2. [Figure 8] Detailed diagram of Step S2. [Figure 9] Detailed diagram of Step S2. [Figure 10] Detailed diagram of Step S5. [Figure 11] Detailed diagram of Step S5. [Figure 12] A second flowchart example illustrating the interpolation procedure. [Figure 13] Detailed diagram of Step S3. [Figure 14] Examples of modified circuit configurations. [Figure 15] Operational diagram of a modified configuration example. [Modes for carrying out the invention]

[0008] Preferred embodiments of this disclosure will be described in detail below. Note that these embodiments are not intended to unduly limit the scope of the claims, and not all configurations described in these embodiments are necessarily essential.

[0009] 1. Electronic equipment, display systems and circuit devices Figure 1 shows an example configuration of an electronic device 500 including a display system 400 according to this embodiment. The electronic device 500 includes a processing unit 300 and a display system 400. The electronic device 500 is, for example, an in-vehicle display device including a meter panel, a center information display, a head-up display, or an electronic mirror, a television device, or an information processing device including a display.

[0010] The display system 400 includes a circuit device 100 and a display device 200. The circuit device 100 is, for example, an integrated circuit device in which multiple circuit elements are integrated on a semiconductor substrate. Although the circuit device 100 and the display device 200 are shown as separate components in Figure 1, the circuit device 100 may be included within the display device 200.

[0011] The 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. An example of the display device 200 is a display used in a television device, an information processing device, or the like. Alternatively, the display device 200 may be a head-mounted display including a projection device for eyes, a head-up display including a projection device for a screen, or the like. When the display device 200 is a head-up display, the display device 200 further includes an optical system for projecting, onto a screen, light emitted from the backlight 210 and transmitted through the display panel 220.

[0012] In a plan view of the backlight 210, light sources are two-dimensionally arranged on the backlight 210. The light sources are light-emitting elements that emit light upon power supply, and are, for example, inorganic light-emitting diodes or organic light-emitting diodes. In local dimming control, the light amounts of the respective two-dimensionally arranged light sources are controlled independently of each other. Alternatively, the backlight 210 may be divided into a plurality of areas. In plan view, a plurality of light sources are arranged in each area. The light sources arranged in an area are controlled to have the same light amount, and the light amounts of the respective areas are controlled independently of each other.

[0013] An example of the two-dimensional arrangement of light sources is a grid arrangement in which light sources are arranged at all intersections of a plurality of rows and a plurality of columns. However, the two-dimensional arrangement is not limited to the grid arrangement. For example, the two-dimensional arrangement may be an arrangement called a rhombic arrangement or a staggered arrangement. In this arrangement, light sources are arranged at intersections between one of odd-numbered rows and even-numbered rows and odd-numbered columns, and at intersections between the other of odd-numbered rows and even-numbered rows and even-numbered columns, and no light sources are arranged at the other intersections.

[0014] The light source driver 240 receives light source luminance data DDIM from the circuit device 100, and drives each light source of the backlight 210 based on the light source luminance data DDIM. The light source driver 240 is, for example, an integrated circuit device. Note that a plurality of light source drivers may be provided, and each of the light source drivers may be a separate integrated circuit device.

[0015] The display panel 220 is an electro-optical panel that transmits light from the backlight 210 and displays an image by controlling the transmittance of the light. For example, the display panel 220 is a liquid crystal display panel.

[0016] The display controller 250 receives image data IMB from the circuit device 100, and transmits the image data IMB and a timing control signal for controlling display timing to the display driver 230. Note that the display controller 250 may perform image processing such as gradation correction, white balance correction, or scaling on the received image data IMB.

[0017] The display driver 230 drives the display panel based on the received image data and timing control signal, thereby causing the display panel 220 to display an image. Note that each of the display controller 250 and the display driver 230 may be configured as separate integrated circuit devices, or may be configured as an integrated integrated circuit device.

[0018] The processing device 300 transmits 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.

[0019] The circuit device 100 receives the image data IMA and performs local dimming control of the display device 200 based on the image data IMA. The circuit device 100 adjusts the luminance of each light source or area of ​​the backlight 210 according to the luminance of the image data IMA, and outputs the light source luminance information obtained from the adjustment as light source luminance data DDIM to the light source driver 240. The circuit device 100 also performs color correction on the image data IMA based on the light source luminance information and outputs the color-corrected image data IMB to the display controller 250.

[0020] Figure 2 shows a detailed configuration example of the circuit device 100. The circuit device 100 includes an interface circuit 110, a light source control circuit 130, a light source brightness determination circuit 140, an illumination brightness calculation circuit 150, a color correction circuit 160, and a storage unit 170.

[0021] The interface circuit 110 receives image data (IMA) from the processing unit 300. The interface circuit 110 may be an interface circuit using various image interface methods such as LVDS, parallel RGB, or DisplayPort. LVDS stands for Low Voltage Differential Signaling.

[0022] The memory unit 170 stores the two-dimensional lookup table 175. The memory unit 170 is a memory circuit such as a register or memory. The memory is a volatile memory such as RAM, or a 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. EEPROM is an abbreviation for Electrically Erasable Programmable Read Only Memory. The processing unit 300 may write the two-dimensional lookup table 175 to the memory unit 170 via an interface circuit such as SPI or I2C. Alternatively, if the memory unit 170 is a non-volatile memory, the two-dimensional lookup table 175 may be stored in the memory unit 170 in advance.

[0023] The 2D lookup table 175 shows the attenuation rate distribution of the light intensity reaching the display panel from the light source. The attenuation rate distribution shows the relationship between the distance from the light source to the pixel and the attenuation rate of the light intensity of the light that illuminates the pixel. The attenuation rate distribution is also called the attenuation characteristic or brightness distribution. The attenuation rate is normalized, with the value for no attenuation at all set to 1, for example. The attenuation rate decreases as the distance from the light source increases, and becomes zero at distances where no light reaches at all. The 2D lookup table is a lookup table that takes horizontal distance and vertical distance as input and outputs the attenuation rate.

[0024] The light source brightness determination circuit 140 determines the light source brightness data LLD, which indicates the luminous brightness of each light source, by performing dimming processing using the image data IMA and the two-dimensional lookup table 175 read from the storage unit 170. In the dimming processing, the light source brightness determination circuit 140 increases the luminous brightness of a light source the higher the brightness of the image surrounding the light source. The algorithm for dimming processing can vary. For example, the light source brightness determination circuit 140 may reduce the image data IMA to a low-resolution image in which pixels exist at each light source position of the backlight, and determine the luminous brightness of each light source based on the pixel value of the low-resolution image corresponding to that light source. Alternatively, the light source brightness determination circuit 140 may find the average or maximum brightness of the image in the area surrounding the light source and determine the luminous brightness of the light source based on that average or maximum brightness. Alternatively, the light source brightness determination circuit 140 may find the required change in brightness to illuminate the pixels on the display panel 220 based on the pixel value of the pixels in the image data IMA and the light source brightness data LLD before updating. The light source brightness determination circuit 140 may also determine the light source brightness data LLD by updating the light source brightness data LLD based on the required change amount and the two-dimensional lookup table 175, and by repeatedly updating while scanning the pixel position.

[0025] The light source control circuit 130 controls the light source driver 240 based on the light source brightness data LLD. Specifically, the light source control circuit 130 outputs a timing control signal to the light source driver 240 that controls the timing of the light emission or the timing of the brightness update of the light source, and also outputs the light source brightness data LLD to the light source driver 240 as light source brightness data DDIM. The light source driver 240 drives each light source with a PWM signal with a pulse width corresponding to the brightness of each light source indicated by the light source brightness data DDIM at the timing defined by the timing control signal. As a result, each light source emits light at a brightness controlled by local dimming.

[0026] The illumination brightness calculation circuit 150 calculates illumination brightness data LPX based on the light source brightness data LLD and the two-dimensional lookup table 175 stored in the memory unit 170. The illumination brightness data LPX indicates the illumination brightness at the position on the display panel 220 corresponding to each pixel of the image data IMA when the display panel 220 is illuminated by the backlight 210.

[0027] The color correction circuit 160 performs color correction on the image data IMA based on the illumination luminance 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 luminance of the light reaching that pixel, and uses the result as the new pixel data for that pixel.

[0028] The light source control circuit 130, the light source brightness determination circuit 140, the illumination brightness calculation circuit 150, and the color correction circuit 160 are logic circuits that process digital signals. Each of the light source control circuit 130, the light source brightness determination circuit 140, the illumination brightness calculation circuit 150, and the color correction circuit 160 may be composed of a separate logic circuit, or some or all of them may be composed of a single logic circuit. Alternatively, the functions of the light source control circuit 130, the light source brightness determination circuit 140, the illumination brightness calculation circuit 150, and the color correction circuit 160 may be realized by executing an instruction set or program that describes the functions of these circuits. Alternatively, the entire circuit device 100 may be a processor such as a CPU, GPU, microcomputer, DSP, ASIC, or FPGA. The functions of the circuit device 100 may be realized by the processor executing an instruction set or program that describes the functions of each part of the circuit device 100.

[0029] The circuit device 100 may include a distortion correction circuit. The distortion correction circuit corrects image distortion caused by the optical system that projects the image displayed on the display panel 220 onto a screen or the like, or by distortion of the screen. Specifically, the distortion correction circuit performs image correction on the image data IMA received by the interface circuit 110 to cancel or reduce the above-mentioned image distortion, and outputs the corrected image data to the light source brightness determination circuit 140, the illumination brightness calculation circuit 150, and the color correction circuit 160. However, the distortion correction circuit may be provided in the processing device 300 instead of the circuit device 100.

[0030] 2. Lighting Brightness Calculation Circuit The calculation method for the illumination luminance data LPX in this embodiment will be described below. First, the basic calculation method will be explained using Figures 3 to 5.

[0031] Figure 3 shows an example of an N-column, M-row arrangement of light sources used in calculating the illumination luminance data LPX. The x-direction is horizontal and corresponds to the horizontal scanning direction of the display panel 220. The y-direction is vertical and corresponds to the vertical scanning direction of the display panel 220.

[0032] The light sources of the backlight 210 are positioned at each point of the grid. The grid is, for example, equally spaced in both the x and y directions. Figure 3 shows an example where the spacing of the light sources in the x direction corresponds to 64 pixels of the display panel 220, and the spacing of the light sources in the y direction corresponds to 64 pixels of the display panel 220. However, the spacing of the light sources is determined according to the model of the display device 200 and is not limited to 64 pixels. Also, the spacing of the light sources in the x direction and the spacing of the light sources in the y direction may be different. Furthermore, the grid does not necessarily have to be equally spaced. Specifically, the light sources of each row may be aligned along the x direction, and the spacing between rows in the y direction may not be equal. Similarly, the light sources of each column may be aligned along the y direction, and the spacing between columns in the x direction may not be equal. In this case as well, the following illumination brightness calculation method can be applied.

[0033] The illumination luminance calculation circuit 150 selects N columns and M rows of light sources arranged around the target pixel PX for which illumination luminance data LPX is to be calculated. Hereinafter, as shown in Figure 3, it is assumed that 4 columns and 4 rows of light sources L1 to L16 are selected. However, N can be an integer of 2 or greater, and M can be an integer of 2 or greater. Let the x-coordinate of the target pixel PX be u and the y-coordinate be v. The illumination luminance calculation circuit 150 selects the light sources in the two columns immediately adjacent to the x-coordinate u in the -x direction, the two columns immediately adjacent to the x-coordinate u in the +x direction, the two columns immediately adjacent to the y-coordinate v in the -y direction, and the two columns immediately adjacent to the y-coordinate v in the +y direction as 4 columns and 4 rows of light sources L1 to L16.

[0034] The illumination brightness calculation circuit 150 calculates the distance between the light source and the target pixel PX as follows: the first horizontal distance Dx1, the second horizontal distance Dx2, the third horizontal distance Dx3, the fourth horizontal distance Dx4, the first vertical distance Dy1, the second vertical distance Dy2, the third vertical distance Dy3, and the fourth vertical distance Dy4. The x-coordinates of the light sources in the first, second, third, and fourth columns are x1, x2, x3, and x4, respectively. The y-coordinates of the light sources in the first, second, third, and fourth rows are y1, y2, y3, and y4, respectively. In this case, Dx1=u-x1, Dx2=u-x2, Dx3=u-x3, Dx4=u-x4, Dy1=v-y1, Dy2=v-y2, Dy3=v-y3, and Dy4=v-y4. Figure 3 shows only the first horizontal distance Dx1 and the first vertical distance Dy1.

[0035] The illumination brightness calculation circuit 150 determines the illumination brightness PXBL of the target pixel PX using the following equation (1). BLi is the emission brightness of the light source Li determined by the light source brightness determination circuit 140. αLi is the attenuation rate of the light reaching the target pixel PX from the light source Li. The illumination brightness calculation circuit 150 determines the attenuation rate αLi by referring to the 2D lookup table 175 based on the horizontal distance Dx and the vertical distance Dy and performing interpolation. The horizontal distance Dx and the vertical distance Dy are selected according to the light source Li. That is, (Dx1, Dy1), (Dx2, Dy1), (Dx3, Dy1), ..., (Dx4, Dy4) are selected according to the light sources L1, L2, L3, ..., L16, respectively.

[0036]

number

[0037] Note that in Figure 3, it is not necessary for light sources to be placed in some parts of the grid. In that case, the illumination luminance calculation circuit 150 calculates the illumination luminance PXBL using equation (1) above, assuming that there are virtual light sources with zero luminance at the locations where no light sources are placed. For example, in a staggered arrangement, L1, L3, L6, L8, L9, L11, L14, and L16 are actual light sources, and L2, L4, L5, L7, L10, L12, L13, and L15 are virtual light sources. In this case, the illumination luminance calculation circuit 150 calculates equation (1) above, assuming BL2=BL4=BL5=BL7=BL10=BL12=BL13=BL15=0.

[0038] Figure 4 shows an example of a two-dimensional lookup table 175. Here, an example of a two-dimensional lookup table 175 with 9 columns and 9 rows is shown, but any table with Kx columns and Ky rows would suffice. Kx is an integer greater than or equal to 2, and Ky is an integer greater than or equal to 2. Also, here an isotropic attenuation characteristic is shown centered on the light source, but an anisotropic attenuation characteristic may also be used.

[0039] The 2D lookup table 175 is a table that takes the horizontal and vertical distances between a light source and a target pixel PX as input and outputs an attenuation rate for those inputs. In the example in Figure 4, the horizontal and vertical distances are shown in pixels, and the distance step is set to 32 pixels. The distance step may be any number of pixels k greater than or equal to 2. The distance step may be normalized by the spacing of the light sources. For example, in Figure 3, the spacing of the light sources is 64 pixels, so in Figure 4, the distance may be normalized by setting 64 pixels to 1. Note that in Figures 5 and beyond, the numerical values ​​of the attenuation rate in the 2D lookup table 175 are not shown. That is, the attenuation rate in the 2D lookup table 175 is shown as blank, but in reality, a numerical value for the attenuation rate is defined.

[0040] Figure 5 is an explanatory diagram of the method for determining the attenuation rate αLi from a two-dimensional lookup table 175. Here, we take the case of determining the attenuation rate αL1 of the light source L1 as an example.

[0041] The illumination brightness calculation circuit 150 reads out the 4x4 element ARA around the first horizontal distance Dx1 and the first vertical distance Dy1 from the 2D lookup table 175. In the example in Figure 5, the element ARA consists of 16 attenuation rates, which are combinations of horizontal distances 32, 64, 96, and 128 and vertical distances 32, 64, 96, and 128. The illumination brightness calculation circuit 150 interpolates the attenuation rate at the position of the first horizontal distance Dx1 and the first vertical distance Dy1 from the 4x4 attenuation rates. The interpolation is, for example, nonlinear interpolation, and bicubic interpolation is one example. Details of the interpolation procedure will be described later. The illumination brightness calculation circuit 150 calculates the attenuation rates αL2 to αL16 in the same manner as above. The illumination brightness calculation circuit 150 uses the calculated attenuation rates αL1 to αL16 and the luminescence BL1 to BL16 of the light sources L1 to L16 to calculate the illumination brightness PXBL of the target pixel PX using equation (1) above.

[0042] Conventionally, the attenuation rate αLi was calculated for each light source Li, and the illumination luminance PXBL was calculated by summing the products in equation (1) above. In that case, interpolation processing such as 2D bicubic interpolation is repeated 16 times in the calculation of the attenuation rate αLi. Furthermore, this process needs to be repeated every time the target pixel PX is moved by one pixel. For example, although nonlinear interpolation has good interpolation accuracy, it has a higher processing load than linear interpolation, and repeating the interpolation for each light source and each pixel results in a large processing load. For example, if the number of light sources used in the calculation of illumination luminance PXBL is increased, the amount of computation increases proportionally.

[0043] In this embodiment, the interpolation processing load is reduced by utilizing the fact that the vertical distance between the light source and the target pixel PX does not change during one horizontal scanning line. The details of the interpolation method in this embodiment will be explained below with reference to Figures 6 to 15.

[0044] Figure 6 shows a first flowchart illustrating the interpolation procedure. In step S1, the illumination brightness calculation circuit 150 obtains the y-coordinate of the target line. The target line is the horizontal scanning line of the object for which the illumination brightness is calculated. The y-coordinate of the target line is the y-coordinate v of the target pixel PX in Figure 3, and does not change while the target pixel PX is scanned along the target line.

[0045] In step S2, the illumination brightness calculation circuit 150 interpolates the two-dimensional lookup table 175 in the y direction for each of the first vertical distances Dy1 to the fourth vertical distance Dy4 to create four one-dimensional lookup tables. Figures 7 to 9 show detailed diagrams of step S2.

[0046] As shown in Figure 7, since the light sources L1 to L16 are arranged in a grid with equal spacing in the y direction, there are four vertical distances between the horizontal scanning line to which the target pixel PX belongs and each light source: the first vertical distance Dy1=v-y1, the second vertical distance Dy2=v-y2, the third vertical distance Dy3=v-y3, and the fourth vertical distance Dy4=v-y4.

[0047] As shown in Figure 8, the illumination brightness calculation circuit 150 creates a first one-dimensional lookup table LUTy1 to a fourth one-dimensional lookup table LUTy4, corresponding to each of the first vertical distances Dy1 to Dy4.

[0048] Figure 9 shows an explanatory diagram of the method for creating the first one-dimensional lookup table LUTy1. The illumination brightness calculation circuit 150 obtains four attenuation rates around the first vertical distance Dy1 from the nine attenuation rates for the horizontal distance -128 in the two-dimensional lookup table 175. In the example in Figure 9, as shown by the dotted rectangle, four attenuation rates for vertical distances of 32, 64, 96, and 128 are obtained. The illumination brightness calculation circuit 150 interpolates the four attenuation rates for vertical distances of 32, 64, 96, and 128 to obtain the attenuation rate for the first vertical distance Dy1, and uses this attenuation rate as the attenuation rate for the horizontal distance -128 in the first one-dimensional lookup table LUTy1. The interpolation is, for example, a nonlinear one-dimensional interpolation, and one example is cubic interpolation. Cubic interpolation is a method of interpolation that approximates using a one-dimensional cubic function.

[0049] The illumination brightness calculation circuit 150 calculates the attenuation rates for horizontal distances of -96, -64, -32, 0, 32, 64, 96, and 128 in the first one-dimensional lookup table LUTy1 by performing similar interpolation. In this way, the first one-dimensional lookup table LUTy1 with 9 columns and 1 row is created. If the two-dimensional lookup table 175 has Kx columns and Ky rows, then the first one-dimensional lookup table LUTy1 will have Kx columns and 1 row. The illumination brightness calculation circuit 150 creates the second one-dimensional lookup table LUTy2 to the fourth one-dimensional lookup table LUTy4 using a similar method.

[0050] In step S4 of Figure 6, the illumination brightness calculation circuit 150 selects a pixel on the target line as the target pixel PX. From the coordinates (u,v) of the target pixel PX, the first horizontal distance Dx1 = u-x1, the second horizontal distance Dx2 = u-x2, the third horizontal distance Dx3 = u-x3, and the fourth horizontal distance Dx4 = u-x4 are determined.

[0051] In step S5, the illumination brightness calculation circuit 150 interpolates the first one-dimensional lookup tables LUTy1 to the fourth one-dimensional lookup table LUTy4 in the x direction for each of the first horizontal distances Dx1 to Dx4, and obtains 16 attenuation rates. Figures 10 and 11 show detailed diagrams of step S5.

[0052] As shown in Figure 10, the illumination brightness calculation circuit 150 obtains four attenuation rates αL1 to αL4 corresponding to the first horizontal distance Dx1 to the fourth horizontal distance Dx4 from the first one-dimensional lookup table LUTy1. These attenuation rates αL1 to αL4 are the attenuation rates of the light reaching the target pixel PX from the light sources L1 to L4.

[0053] Figure 11 shows an explanatory diagram of the method for determining the attenuation rate αL1. The illumination brightness calculation circuit 150 obtains four attenuation rates around the first horizontal distance Dx1 from among the nine attenuation rates in the first one-dimensional lookup table LUTy1. In the example in Figure 11, as shown by the dotted rectangle, four attenuation rates are obtained for horizontal distances of 32, 64, 96, and 128. The illumination brightness calculation circuit 150 interpolates these four attenuation rates for horizontal distances of 32, 64, 96, and 128 to determine the attenuation rate for the first horizontal distance Dx1, and sets this attenuation rate as the attenuation rate αL1 corresponding to the light source L1. The interpolation is, for example, a nonlinear one-dimensional interpolation, and one example is cubic interpolation. Note that if the one-dimensional interpolation is cubic interpolation, the cubic interpolation in the y direction in Figure 9 and the cubic interpolation in the x direction in Figure 11 are combined to obtain bicubic interpolation.

[0054] Similarly, the lighting brightness calculation circuit 150 obtains the attenuation rates αL2 to αL4 corresponding to light sources L2 to L4 from the first one-dimensional lookup table LUTy1. Similarly, the lighting brightness calculation circuit 150 obtains the attenuation rates αL5 to αL8 corresponding to light sources L5 to L8 from the second one-dimensional lookup table LUTy2. The lighting brightness calculation circuit 150 obtains the attenuation rates αL9 to αL12 corresponding to light sources L9 to L12 from the third one-dimensional lookup table LUTy3. The lighting brightness calculation circuit 150 obtains the attenuation rates αL13 to αL16 corresponding to light sources L13 to L16 from the fourth one-dimensional lookup table LUTy4.

[0055] In step S7 of Figure 6, the illumination brightness calculation circuit 150 calculates the illumination brightness PXBL of the target pixel PX using equation (1) above. In step S8, the illumination brightness calculation circuit 150 determines whether or not the illumination brightness PXBL has been calculated for all pixels of the target line. If there are pixels for which the illumination brightness PXBL has not been calculated, steps S4 to S8 are executed. If the illumination brightness PXBL has been calculated for all pixels, the illumination brightness calculation circuit 150 finishes calculating the illumination brightness for the target line.

[0056] Since the first vertical distance Dy1 to the fourth vertical distance Dy4 between the light source and the target pixel PX do not change during one horizontal scan line, the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 in step S2 are calculated only once per horizontal scan line. When determining the illumination luminance PXBL for each pixel, only x-direction interpolation is performed, which significantly reduces the processing load compared to performing two-dimensional interpolation for each pixel.

[0057] Figure 12 shows a second flowchart illustrating the interpolation procedure. Steps S1, S2, S4, S7, and S8 are the same as in the first flowchart in Figure 6. The differences from the first flowchart are explained below.

[0058] In step S3, the illumination brightness calculation circuit 150 interpolates the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 obtained in step S2 in the x direction to create the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int. Figure 13 shows a detailed diagram of step S3.

[0059] As shown in Figure 13, the illumination brightness calculation circuit 150 calculates the first interpolated one-dimensional lookup table LUTy1_int by interpolating the first one-dimensional lookup table LUTy1 in the x direction to determine the attenuation rate for each pixel. The two-dimensional lookup table 175 has 9 columns, and the horizontal distance step between columns is 32 pixels. In this case, the number of columns in the first interpolated one-dimensional lookup table LUTy1_int is (9-1)×32+1=257. If the two-dimensional lookup table 175 has Kx columns and the horizontal distance step between columns is k pixels, the number of columns in the first interpolated one-dimensional lookup table LUTy1_int is (Kx-1)×k+1.

[0060] The illumination brightness calculation circuit 150 similarly creates the second interpolated one-dimensional lookup table LUTy2_int to the fourth interpolated one-dimensional lookup table LUTy4_int from the second one-dimensional lookup table LUTy2 to the fourth one-dimensional lookup table LUTy4.

[0061] In step S6 of Figure 12, the illumination brightness calculation circuit 150 refers to the first interpolated one-dimensional lookup table LUTy1_int to obtain αL1 to αL4 corresponding to the first horizontal distance Dx1 to the fourth horizontal distance Dx4. These attenuation rates αL1 to αL4 are the attenuation rates of the light reaching the target pixel PX from the light sources L1 to L4, respectively. Similarly, the illumination brightness calculation circuit 150 refers to the second interpolated one-dimensional lookup table LUTy2_int to obtain attenuation rates αL5 to αL8 corresponding to the light sources L5 to L8. The illumination brightness calculation circuit 150 refers to the third interpolated one-dimensional lookup table LUTy3_int to obtain attenuation rates αL9 to αL12 corresponding to the light sources L9 to L12. The illumination brightness calculation circuit 150 refers to the fourth interpolated one-dimensional lookup table LUTy4_int to obtain attenuation rates αL13 to αL16 corresponding to the light sources L13 to L16.

[0062] Figure 14 shows an example of a modified configuration of the circuit device 100. The circuit device 100 further includes a buffer memory 180 that stores a one-dimensional lookup table or an interpolated one-dimensional lookup table. The buffer memory 180 is, for example, a semiconductor memory such as SRAM or DRAM. Note that the interface circuit 110, the light source brightness determination circuit 140, the light source control circuit 130, and the color correction circuit 160 are omitted from the illustration in Figure 14.

[0063] When the configuration of Figure 14 is applied to the first flow example in Figure 6, the buffer memory 180 temporarily stores the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4. When the configuration of Figure 14 is applied to the second flow example in Figure 12, the buffer memory 180 temporarily stores the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int. The buffer memory 180 includes a first buffer 181 and a second buffer 182. The first buffer 181 temporarily stores the one-dimensional lookup table or interpolated one-dimensional lookup table calculated for one of the odd-numbered and even-numbered lines. The second buffer 182 temporarily stores the one-dimensional lookup table or interpolated one-dimensional lookup table calculated for the other of the odd-numbered and even-numbered lines. Note that the buffer memory 180 may contain three or more buffers. For example, if buffer memory 180 includes the first buffer to the third buffer, the first buffer to the third buffer will cyclically store temporary data every three lines.

[0064] Figure 15 is an explanatory diagram of the operation of a modified configuration example of Figure 14. First, we will explain the operation when the configuration of Figure 14 is applied to the first flow example in Figure 6.

[0065] During the horizontal scanning period immediately preceding the first line, the illumination brightness calculation circuit 150 performs steps S1 and S2 in Figure 6, treating the first line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 obtains the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 by interpolating the two-dimensional lookup table 175 vertically using the y-coordinate of the first line. The illumination brightness calculation circuit 150 updates the first buffer 181 by writing the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 to the first buffer 181.

[0066] During the horizontal scanning period of the first line, the illumination brightness calculation circuit 150 executes steps S4 to S8 in Figure 6, treating the first line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 reads the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 from the first buffer 181 and uses them to calculate the illumination brightness PXBL for each pixel of the first line.

[0067] Furthermore, during the horizontal scanning period of the first line, the illumination brightness calculation circuit 150 executes steps S1 and S2 in Figure 6, treating the next second line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 calculates the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 by interpolating the two-dimensional lookup table 175 vertically using the y coordinate of the second line. The illumination brightness calculation circuit 150 updates the second buffer 182 by writing the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 to the second buffer 182.

[0068] During the horizontal scanning period of the second line, the illumination brightness calculation circuit 150 executes steps S4 to S8 in Figure 6, treating the second line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 reads the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 from the second buffer 182 and uses them to calculate the illumination brightness PXBL for each pixel of the second line.

[0069] Furthermore, during the horizontal scanning period of the second line, the illumination brightness calculation circuit 150 executes steps S1 and S2 in Figure 6, treating the next third line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 calculates the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 by interpolating the two-dimensional lookup table 175 vertically using the y-coordinate of the third line. The illumination brightness calculation circuit 150 updates the first buffer 181 by writing the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 to the first buffer 181. Thereafter, the illumination brightness calculation circuit 150 repeats the same operation during the horizontal scanning period of each line.

[0070] Next, we will explain the operation when the configuration of Figure 14 is applied to the second flow example in Figure 12. In the horizontal scanning period immediately preceding the first line, the illumination brightness calculation circuit 150 executes steps S1 to S3 in Figure 12, treating the first line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 interpolates the 2D lookup table 175 vertically using the y coordinate of the first line, and then interpolates it further in the x direction to obtain the first interpolated 1D lookup table LUTy1_int to the fourth interpolated 1D lookup table LUTy4_int. The illumination brightness calculation circuit 150 updates the first buffer 181 by writing the first interpolated 1D lookup table LUTy1_int to the fourth interpolated 1D lookup table LUTy4_int to the first buffer 181.

[0071] During the horizontal scanning period of the first line, the illumination brightness calculation circuit 150 executes steps S4 to S8 in Figure 12, treating the first line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 reads the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int from the first buffer 181 and uses them to calculate the illumination brightness PXBL for each pixel of the first line.

[0072] Furthermore, during the horizontal scanning period of the first line, the illumination brightness calculation circuit 150 executes steps S1 to S3 in Figure 12, treating the next second line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 interpolates the two-dimensional lookup table 175 vertically using the y coordinate of the second line, and then interpolates it further in the x direction to obtain the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int. The illumination brightness calculation circuit 150 updates the second buffer 182 by writing the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int to the second buffer 182.

[0073] During the horizontal scanning period of the second line, the illumination brightness calculation circuit 150 executes steps S4 to S8 in Figure 12, treating the second line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 reads the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int from the second buffer 182 and uses them to calculate the illumination brightness PXBL for each pixel of the second line.

[0074] Furthermore, during the horizontal scanning period of the second line, the illumination brightness calculation circuit 150 executes steps S1 to S3 in Figure 12, treating the next third line as the target horizontal scanning line. That is, the illumination brightness calculation circuit 150 interpolates the two-dimensional lookup table 175 vertically using the y coordinate of the third line, and then interpolates it further in the x direction to obtain the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int. The illumination brightness calculation circuit 150 updates the first buffer 181 by writing the first interpolated one-dimensional lookup table LUTy1_int to the fourth interpolated one-dimensional lookup table LUTy4_int to the first buffer 181. Thereafter, the illumination brightness calculation circuit 150 repeats the same operation during the horizontal scanning period of each line.

[0075] In this embodiment, the circuit device 100 controls the display device 200 with local dimming. The display device 200 includes a backlight 210 having a plurality of light sources arranged in two dimensions, and a display panel 220. The circuit device 100 includes a light source brightness determination circuit 140, an illumination brightness calculation circuit 150, and a color correction circuit 160. The light source brightness determination circuit 140 outputs light source brightness data LLD, which indicates the luminous brightness of each light source of the backlight 210, based on the image data IMA. The illumination brightness calculation circuit 150 calculates illumination brightness data LPX, which indicates the brightness of the light reaching the target pixel PX from light sources in N columns and M rows around the target pixel PX of the display panel 220, based on a two-dimensional lookup table 175 showing the attenuation rate distribution of light sources and the light source brightness data LLD. The color correction circuit 160 performs color correction on the image data of the target pixel PX based on the illumination brightness data 150 and outputs the color-corrected image data IMB to the display device 200. The illumination brightness calculation circuit 150 calculates the first one-dimensional lookup tables LUTy1 to the Mth one-dimensional lookup tables LUTyM by interpolating the attenuation rate of the two-dimensional lookup table 175 vertically for the first vertical distance Dy1 to the Mth vertical distance DyM, which are the vertical distances between the target line containing the target pixel PX and each light source in the M rows. The illumination brightness calculation circuit 150 calculates the illumination brightness data LPX based on the first one-dimensional lookup tables LUTy1 to the Mth one-dimensional lookup tables LUTyM, the first horizontal distances Dx1 to the Nth horizontal distance DxN, which are the horizontal distances between the target pixel PX and each light source in the N columns, and the light source brightness data LLD. In the examples in Figures 3 to 15, N=4 and M=4 were used for explanation.

[0076] According to this embodiment, the first vertical distance Dy1 to the Mth vertical distance DyM between the light source and the target pixel PX do not change during the horizontal scanning of the target line. Therefore, the first one-dimensional lookup table LUTy1 to the fourth one-dimensional lookup table LUTy4 only need to be calculated once for the target line. When determining the illumination luminance PXBL for each pixel of the target line, only x-direction interpolation is performed, and y-direction interpolation is shared. As a result, the processing load is significantly reduced compared to when a two-dimensional interpolation of the lookup table is performed for each pixel.

[0077] As explained in Figure 15, the illumination brightness calculation circuit 150 may also obtain the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM during the horizontal scanning period of the line preceding the target line.

[0078] During the horizontal scanning period of lines preceding the target line, the vertical coordinates of the target line are known. For example, if the calculation is performed one line prior, the next line can be used as the target line. Therefore, the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM can be calculated during the horizontal scanning period of lines preceding the target line. By performing vertical interpolation in a horizontal scanning period separate from the horizontal interpolation, the processing can be distributed.

[0079] As explained in Figure 4, the two-dimensional lookup table 175 may also be a lookup table with Kx columns and Ky rows. As explained in Figures 7 to 9, each of the one-dimensional lookup tables from the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM may also have Kx columns and 1 row. In the examples in Figures 4 to 15, Kx=9 and Ky=9 were used for explanation.

[0080] According to this embodiment, by interpolating the two-dimensional lookup table 175 vertically to create a one-dimensional lookup table with one row and Kx columns, the attenuation rate corresponding to each light source can be determined by interpolating that one-dimensional lookup table in the x direction.

[0081] Furthermore, as explained in Figures 10 and 11, the illumination brightness calculation circuit 150 may also calculate N × M attenuation rates by interpolating the attenuation rates of each one-dimensional lookup table horizontally for the first horizontal distance Dx1 to the Nth horizontal distance DxN. As explained in equation (1) above, the illumination brightness calculation circuit 150 may also calculate the illumination brightness data LPX by performing a calculation that includes the sum of the products of the obtained N × M attenuation rates and the luminous brightness of the light source in N columns and M rows.

[0082] According to this embodiment, when calculating the illumination luminance PXBL of a target pixel PX, the attenuation rate of light reaching the target pixel PX from the light source can be calculated by interpolating a one-dimensional lookup table based on the horizontal distance between the target pixel PX and the light source. In equation (1) above, the illumination luminance PXBL is calculated by the sum of the products of the luminescence luminance and the attenuation rate, but the illumination luminance PXBL can be calculated by any calculation that includes the sum of the products of the luminescence luminance and the attenuation rate. For example, the products of the luminescence luminance, the attenuation rate and the coefficient may be summed, or some term other than the sum of products term may be added.

[0083] As explained in Figure 14, the circuit device 100 may also include a buffer memory 180 that stores the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM. As explained in Figures 6 and 15, the buffer memory 180 may include a first buffer 181 and a second buffer 182. The first buffer 181 may store the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM when the target line is the first line. The second buffer 182 may store the first one-dimensional lookup table LUTy1 to the Mth one-dimensional lookup table LUTyM when the target line is the second line.

[0084] According to this embodiment, a one-dimensional lookup table for the first line can be calculated and temporarily stored in the first buffer 181 before the horizontal scanning period of the first line. Then, during the horizontal scanning period of the first line, the one-dimensional lookup table can be read from the first buffer 181 to determine the attenuation rate for the target pixel PX, and a one-dimensional lookup table for the second line can be calculated and temporarily stored in the second buffer 182.

[0085] As explained in Figure 13, the illumination brightness calculation circuit 150 may also calculate the first interpolated one-dimensional lookup table LUTy1_int to the Mth interpolated one-dimensional lookup table LUTyM_int by interpolating the attenuation rate of each one-dimensional lookup table horizontally to obtain the attenuation rate for each pixel interval in the horizontal direction.

[0086] According to this embodiment, by interpolating the two-dimensional lookup table 175 vertically and then horizontally to create an interpolated one-dimensional lookup table with a 1-pixel interval, the attenuation rate corresponding to each light source can be determined by referring to this interpolated one-dimensional lookup table.

[0087] Furthermore, as explained in Figures 12 and 15, the illumination brightness calculation circuit 150 may calculate the first interpolated one-dimensional lookup table LUTy1_int to the Mth interpolated one-dimensional lookup table LUTyM_int during the horizontal scanning period of the line preceding the target line.

[0088] According to this embodiment, when determining the attenuation rate of each pixel during the horizontal scanning period of the target line, it is only necessary to refer to the interpolated one-dimensional lookup table, thus eliminating the processing load of interpolation.

[0089] As explained in Figure 12, the illumination brightness calculation circuit 150 may also obtain N × M attenuation rates corresponding to the first horizontal distance Dx1 to the Nth horizontal distance DxN from each interpolated one-dimensional lookup table. As explained in equation (1) above, the illumination brightness calculation circuit 150 may also calculate the illumination brightness data LPX by performing a calculation that includes the sum of the products of the obtained N × M attenuation rates and the luminous brightness of the light source in N columns and M rows.

[0090] According to this embodiment, when calculating the illumination brightness PXBL of a target pixel PX, the attenuation rate of light reaching the target pixel PX from the light source can be obtained by referring to an interpolated one-dimensional lookup table based on the horizontal distance between the target pixel PX and the light source.

[0091] As also explained in Figure 14, the circuit device 100 may include a buffer memory 180 that stores the first interpolated one-dimensional lookup table LUTy1_int to the Mth interpolated one-dimensional lookup table LUTyM_int. The buffer memory 180 may include a first buffer 181 that stores the first interpolated one-dimensional lookup table LUTy1_int to the Mth interpolated one-dimensional lookup table LUTyM_int when the target line is the first line, and a second buffer 182 that stores the first interpolated one-dimensional lookup table LUTy1_int to the Mth interpolated one-dimensional lookup table LUTyM_int when the target line is the second line.

[0092] According to this embodiment, an interpolated one-dimensional lookup table for the first line can be calculated and temporarily stored in the first buffer 181 before the horizontal scanning period of the first line. Then, during the horizontal scanning period of the first line, the attenuation rate for the target pixel PX can be obtained by referring to the interpolated one-dimensional lookup table stored in the first buffer 181, and an interpolated one-dimensional lookup table for the second line can be calculated and temporarily stored in the second buffer 182.

[0093] As explained in Figure 3, multiple light sources may also be arranged in a grid with equal spacing in the horizontal and vertical directions.

[0094] By arranging the light sources in a vertically spaced grid, the vertical distance between the target line (which is a horizontal scanning line) and the light sources in the N column and M row is reduced to only M values. This means that the 2D lookup table 175 only needs to be interpolated for these M vertical distances, reducing the processing load compared to when the light sources are not arranged in a grid.

[0095] Furthermore, as explained in equation (1) above, if no light source is located in a portion of the N-column, M-row grid surrounding the target pixel PX, the illumination brightness calculation circuit 150 may calculate the illumination brightness data LPX by considering the luminescence brightness of the light source in that grid as zero.

[0096] The lookup table interpolation method in this embodiment can be applied to any light source arrangement that excludes some light sources from a grid arrangement.

[0097] In this embodiment, the display system 400 includes the circuit device 100 described in any of the above and the display device 200.

[0098] Although this embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novelty and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, any term that appears at least once in the specification or drawings together with a broader or synonymous term may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. In addition, the configuration and operation of the circuit device, backlight, display panel, display device, display system, and processing device, etc., are not limited to those described in this embodiment, and various modifications are possible. [Explanation of Symbols]

[0099] 100...Circuit device, 110...Interface circuit, 130...Light source control circuit, 140...Light source brightness determination circuit, 150...Illumination brightness calculation circuit, 160...Color correction circuit, 170...Memory unit, 175...2D lookup table, 180...Buffer memory, 181...First buffer, 182...Second buffer, 200...Display device, 210...Backlight, 220...Display panel, 230...Display driver, 240...Light source driver, 250...Display controller, 300...Processing device, 400...Display system, 500...Electronic equipment, BL1~BL16...Emitting light Brightness, DDIM…Light source brightness data, Dx1~Dx4…1st horizontal distance~4th horizontal distance, Dy1~Dy4…1st vertical distance~4th vertical distance, IMA, IMB…Image data, L1~L16…Light source, LLD…Light source brightness data, LPX…Illumination brightness data, LUTy1~LUTy4…1st 1D lookup table~4th 1D lookup table, LUTy1_int~LUTy4_int…1st interpolated 1D lookup table~4th interpolated 1D lookup table, PX…Target pixel, PXBL…Illumination brightness, αL1~αL16…Attenuation rate

Claims

1. A circuit device for locally dimming a display device that includes a backlight having multiple light sources arranged in two dimensions and a display panel, A light source brightness determination circuit that outputs light source brightness data indicating the luminous brightness of each light source of the backlight based on image data, An illumination brightness calculation circuit calculates illumination brightness data indicating the brightness of light reaching the target pixel from N columns and M rows of light sources (N is an integer of 2 or more, M is an integer of 2 or more) around the target pixel of the display panel, based on a two-dimensional lookup table showing the attenuation rate distribution of light sources and the light source brightness data. A color correction circuit that performs color correction on the image data of the target pixel based on the illumination brightness data and outputs the color-corrected image data to the display device, Includes, The aforementioned illumination brightness calculation circuit is For the first to the Mth vertical distances, which are the vertical distances between the target line containing the target pixel and each row light source in the M rows, the attenuation rate of the two-dimensional lookup table is interpolated vertically to obtain the first to the Mth one-dimensional lookup table. A circuit device characterized by calculating illumination brightness data based on the first one-dimensional lookup table to the M one-dimensional lookup table, the first to N horizontal distances which are the horizontal distances between the target pixel and each column light source in column N, and the light source brightness data.

2. In the circuit device described in claim 1, The aforementioned illumination brightness calculation circuit is A circuit device characterized by determining the first one-dimensional lookup table to the M one-dimensional lookup table during the horizontal scanning period of the line preceding the target line.

3. In the circuit device described in claim 1, The aforementioned two-dimensional lookup table is a lookup table with Kx columns and Ky rows (where Kx is an integer greater than or equal to 2, and Ky is an integer greater than or equal to 2), A circuit device characterized in that each of the one-dimensional lookup tables from the first one-dimensional lookup table to the M one-dimensional lookup table has Kx columns and 1 row.

4. In the circuit device described in claim 3, The aforementioned illumination brightness calculation circuit is For the first horizontal distance to the N horizontal distance, the attenuation rates of each one-dimensional lookup table are interpolated horizontally to obtain N × M attenuation rates. A circuit device characterized by calculating the illumination brightness data by performing a calculation that includes the sum of the products of the N × M attenuation rates obtained and the luminous brightness of the N columns and M rows of light sources.

5. In the circuit device described in claim 4, The system includes a buffer memory that stores the first one-dimensional lookup table to the M one-dimensional lookup table, The aforementioned buffer memory is A first buffer that stores the first one-dimensional lookup table to the first one-dimensional lookup table of M when the target line is the first line, A second buffer that stores the first one-dimensional lookup table to the first one-dimensional lookup table of M when the target line is the second line, A circuit device characterized by including the following.

6. In the circuit device described in claim 3, The aforementioned illumination brightness calculation circuit is A circuit device characterized by obtaining the first interpolated one-dimensional lookup table to the Mth interpolated one-dimensional lookup table by interpolating the attenuation rate of each of the aforementioned one-dimensional lookup tables in the horizontal direction to obtain the attenuation rate for each pixel interval in the horizontal direction.

7. In the circuit device described in claim 6, The aforementioned illumination brightness calculation circuit is A circuit device characterized by obtaining the first interpolated one-dimensional lookup table to the M interpolated one-dimensional lookup table during the horizontal scanning period of the line preceding the target line.

8. In the circuit device described in claim 6, The aforementioned illumination brightness calculation circuit is By obtaining the attenuation rates corresponding to the first horizontal distance to the N horizontal distance from each interpolated one-dimensional lookup table, N × M attenuation rates are obtained. A circuit device characterized by calculating the illumination brightness data by performing a calculation that includes the sum of the products of the N × M attenuation rates obtained and the luminous brightness of the N columns and M rows of light sources.

9. In the circuit device described in claim 8, The system includes a buffer memory that stores the first interpolated one-dimensional lookup table to the M interpolated one-dimensional lookup table, The aforementioned buffer memory is A first buffer that stores the first interpolated one-dimensional lookup table to the M interpolated one-dimensional lookup table when the target line is the first line, A second buffer that stores the first interpolated one-dimensional lookup table to the M interpolated one-dimensional lookup table when the target line is the second line, A circuit device characterized by including the following.

10. In the circuit device described in claim 1, The circuit device is characterized in that the plurality of light sources are arranged in a grid with equal intervals in the horizontal and vertical directions.

11. In the circuit device described in claim 10, The aforementioned illumination brightness calculation circuit is A circuit device characterized in that, if no light source is placed in a portion of an N-column, M-row grid surrounding the target pixel, the illumination brightness data is calculated by considering the luminescence brightness of the light source in that grid as zero.

12. A circuit device according to any one of claims 1 to 11, The display device and, A display system characterized by including the following.

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