Backlight control method and display device

Abstract

The application relates to a backlight control method and a display device, which comprises a liquid crystal panel, a backlight module and a control module; the control module is configured to: acquire a normalized linear optical gray scale value and a normalized brightness stimulus value of pixels in a target display area in to-be-displayed frame image data; based on the normalized brightness stimulus value, the normalized linear optical gray scale value and a maximum allowed desaturation degree condition of each pixel in the target display area, a desaturation coefficient of a target backlight area corresponding to the target display area is solved; based on the desaturation coefficient and the normalized brightness stimulus value of each pixel in the target display area, color splitting processing is performed to determine the normalized driving brightness value of each light emitting device in the target backlight area under each different color subfield and the normalized linear transmittance of each pixel in the target display area, so as to be used for driving control of the target backlight area and the target display area. The desaturation coefficient is solved in real time without iteration, and quality improvement and power consumption optimization are realized.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a backlight control method and display device. Background Technology

[0002] With the rapid iteration of display technology, terminal devices are continuously increasing their requirements for display quality accuracy and power consumption control. In liquid crystal display (LCD) devices, traditional RGB backlighting relies on the mixing of three colors to synthesize white light, resulting in high energy consumption. In contrast, the RGBW backlight architecture adds an independent white light channel, which can effectively improve backlight output efficiency and panel brightness, optimize module light transmission performance, and reduce the workload of the RGB channel by sharing the neutral color emission with the white light channel. This reduces the overall power consumption of the device while ensuring excellent display level and white light purity, and has outstanding industrial application value.

[0003] However, RGBW four-channel mixing inherently suffers from color desaturation issues. Related technologies often employ iterative optimization algorithms to solve for desaturated primary colors. This method is not only computationally complex and computationally expensive, but also has limited accuracy and large coefficient errors. Even after color correction, noticeable color casts and other low-quality defects remain, limiting the industrial application of RGBW backlight architectures. Summary of the Invention

[0004] Therefore, it is necessary to provide a backlight control method and display device to address the above-mentioned technical problems. This method can solve the desaturation coefficient in real time without iteration based on the image data of the frame to be displayed, thereby improving the efficiency of desaturation coefficient solution, reducing coefficient error, and achieving image quality improvement and power consumption optimization.

[0005] In a first aspect, this application provides a display device, including a liquid crystal panel, a backlight module and a control module, wherein the liquid crystal panel is configured to sequentially display images corresponding to multiple subfields within a single frame image period;

[0006] The control module is configured as follows:

[0007] The nonlinear digital grayscale values ​​of pixels within the target display area in the image data of the display frame are subjected to gamma conversion to determine the normalized linear optical grayscale values ​​of the pixels, and the normalized luminance stimulus values ​​of the pixels in the color space are determined based on the normalized linear optical grayscale values ​​of the pixels.

[0008] Based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved; where the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to take the value of [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel, and B channel allocated to the W channel;

[0009] Color splitting is performed based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

[0010] Based on the same inventive concept, in a second aspect, this application provides a backlight control method applied to a display device, the display device including at least a liquid crystal panel and a backlight module, the liquid crystal panel being configured to sequentially display images corresponding to multiple subfields within a single frame image period;

[0011] The method includes:

[0012] The nonlinear digital grayscale values ​​of pixels within the target display area in the image data of the display frame are subjected to gamma conversion to determine the normalized linear optical grayscale values ​​of the pixels, and the normalized luminance stimulus values ​​of the pixels in the color space are determined based on the normalized linear optical grayscale values ​​of the pixels.

[0013] Based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved; where the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to take the value of [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel, and B channel allocated to the W channel;

[0014] Color splitting is performed based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

[0015] The aforementioned backlight control method and display device determine the normalized linear optical grayscale value of the pixel in the target display area and the normalized luminance stimulus value of the pixel in the color space in the image data of the frame to be displayed. Then, based on the normalized luminance stimulus value, normalized linear optical grayscale value and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved, thereby realizing the real-time non-iterative analytical solution of the desaturation coefficient of the target backlight area. Because the solution proposed in this application always uses the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of the pixels in the image data of the frame to be displayed to perform a non-iterative analytical solution for the backlight desaturation coefficient within the color space, it achieves a non-iterative analytical solution for the backlight desaturation coefficient based on the image data of the frame to be displayed within the color space. This improves the efficiency of the desaturation coefficient solution, reduces coefficient errors, and ensures that the color coordinates of the desaturated RGB primary colors fall on the line connecting the white point color coordinates and the corresponding native RGB primary color coordinates. This improves the defects of color gamut shift and color coordinate drift in related technologies that cause color reproduction distortion of the input image. At the same time, it helps to improve the defects of large spectral jump amplitude between subfields in related technologies that cause color separation or flickering in moving images, thus achieving image quality improvement and power consumption optimization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural block diagram of a display device according to an embodiment of this application;

[0018] Figure 2 This is a flowchart illustrating the steps performed by the control module in one embodiment of this application;

[0019] Figure 3 This is one of the flowcharts illustrating step S202 in one embodiment of this application;

[0020] Figure 4 This is a second flowchart illustrating step S202 in one embodiment of this application. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0022] In the following text, although terms such as “first” and “second” may be used to describe various components, these components are not necessarily limited to the terms above. The terms above are used only to distinguish one component from another. It will also be understood that expressions used in the singular form include plural expressions unless the singular form has a distinct meaning in the context. Furthermore, in the embodiments below, it will also be understood that the terms “comprising” and / or “having” as used herein indicate the presence of the stated feature or component, but do not exclude the presence or addition of one or more other features or components.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, portions, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, portions, or combinations thereof.

[0024] As mentioned in the background section, RGBW four-channel mixing inherently suffers from color desaturation. Related technologies often employ iterative optimization algorithms to solve for desaturated primary colors. However, the inventors of this application have discovered that this method directly solves for desaturated primary colors based on the nonlinear digital grayscale values ​​of sub-pixels and preset coefficients. Then, backlight driving brightness is calculated based on the solved desaturated primary colors. To ensure color accuracy, a color correction module is added to calculate the color difference between the output image and the input image. The extracted white light component value is corrected in reverse based on the color overflow component (such as adjusting preset coefficients). The overall process is not only computationally complex and computationally expensive, but also has limited solution accuracy and large coefficient errors. Even after color correction, there are still obvious color casts and other low-quality defects, which limits the industrial application of the RGBW backlight architecture.

[0025] For the reasons mentioned above, the backlight control method and display device provided in at least one embodiment of the solution disclosed in this application can solve the desaturation coefficient in real time without iteration based on the image data of the frame to be displayed, thereby improving the efficiency of desaturation coefficient solution, reducing coefficient error, and achieving image quality improvement and power consumption optimization.

[0026] Color field sequence display is one of the methods for display devices to achieve color display. Its principle includes: the backlight module adopts an RGBW backlight architecture, and refreshes the four colors of backlight (R, G, B, and W) sequentially within a field time (i.e., the display cycle of one frame of color image). The panel driving module adjusts the transmittance of each backlight, and displays the four color sub-frame images sequentially on the LCD panel in a time-division manner. By utilizing the hysteresis effect of the human eye, the four color sub-frame images are fused in time. In this way, the four color sub-frame images are finally combined into a single color image in the human eye.

[0027] A liquid crystal display device that achieves color display using a field-sequential color liquid crystal display method is called a field-sequential color liquid crystal display (FSC LCD), or simply a field-sequential display device. The display device provided in the embodiments of this application is, for example, but not limited to, a field-sequential display device. It should be understood that the display device provided in the embodiments of this application may or may not include a color filter; this is not specifically limited. Furthermore, the image of a subframe can be a monochrome image (such as a red image, green image, blue image, or white image) or a color image based on multiple primary colors; this is not specifically limited.

[0028] In one exemplary embodiment, reference is made to Figure 1 A display device is provided, which includes a liquid crystal panel, a backlight module, and a control module.

[0029] The liquid crystal panel includes a first substrate, a second substrate disposed adjacent to the first substrate, and a liquid crystal layer located between the first and second substrates after the substrates are aligned. Based on this, the liquid crystal panel may include a plurality of pixels arranged in an array, each pixel may include a plurality of sub-pixels. In some embodiments, each pixel may include a red sub-pixel (i.e., R sub-pixel), a green sub-pixel (i.e., G sub-pixel), and a blue sub-pixel (i.e., B sub-pixel). The liquid crystal panel is configured to sequentially display images corresponding to a plurality of subfields within a single frame image period.

[0030] The backlight module is located on the side of the LCD panel opposite to the display side, and provides a backlight source corresponding to the subfield for the LCD panel. The liquid crystal layer controls the amount of light transmitted through the LCD panel by flipping. The backlight module can be an RGBW backlight architecture, where the R, G, B, and W primary colors can be realized by red, green, blue, and white light-emitting devices, respectively. The light-emitting devices include, but are not limited to, light-emitting diodes (LEDs).

[0031] The liquid crystal panel may include a non-display area and a full display area, the full display area may be divided into multiple display zones, each display zone including at least one pixel; the backlight module may include a full backlight area, the full backlight area may be divided into multiple backlight zones (i.e., dimming zones), each backlight zone including at least one light-emitting device. In some embodiments, the full backlight area of ​​the backlight module corresponds to the full display area of ​​the liquid crystal panel, each backlight zone corresponds to one display zone, and light emitted from a backlight zone can illuminate its corresponding display zone.

[0032] refer to Figure 2 The control module is configured to perform at least the following steps S201~S203.

[0033] S201, perform gamma conversion on the nonlinear digital grayscale values ​​of pixels in the target display area of ​​the image data to be displayed to determine the normalized linear optical grayscale values ​​of the pixels, and determine the normalized luminance stimulus values ​​of the pixels in the color space based on the normalized linear optical grayscale values ​​of the pixels.

[0034] The control module can acquire image data of the frame to be displayed. The image data of the frame to be displayed contains a number of image pixels, and each image pixel has a corresponding physical pixel on the liquid crystal panel. In some embodiments, each image pixel corresponds one-to-one with a physical pixel on the liquid crystal panel. Hereinafter, both image pixels and physical pixels will be referred to simply as pixels.

[0035] The target display area can be the entire display area or a display partition of the LCD panel. The pixels within the target display area in the image data of the frame to be displayed refer to the image pixels in the image data of the frame to be displayed that correspond to the physical pixels within the target display area. In the following text, the pixels in the nonlinear digital grayscale value, normalized linear optical grayscale value, normalized luminance stimulus value, and maximum permissible desaturation condition of a pixel can all refer to image pixels; the normalized linear transmittance of a pixel can refer to the normalized linear transmittance of a physical pixel. In the following text, all normalized parameters indicate that their values ​​are normalized and take values ​​[0, 1].

[0036] The nonlinear digital grayscale value and the normalized linear optical grayscale value of a pixel can be derived from each other through forward gamma conversion (also known as γ correction) and inverse gamma conversion, respectively. The nonlinear digital grayscale value of a pixel, commonly referred to / known in this technical field as "Gray," is a discrete digital code value that has a nonlinear mapping relationship with the actual luminance of the pixel to the power of γ. The normalized linear optical grayscale value of a pixel is a dimensionless proportional value taking values ​​in the range [0, 1]. This value has a linear proportional relationship with the actual luminance of the pixel and can be used for subsequent optical color splitting calculations.

[0037] The following description uses an 8-bit image encoding scenario as an example to illustrate the solution of this application, but this is not intended to limit the invention. For example, the solution of this application is not limited to other image encoding scenarios such as 10-bit, 12-bit, or 16-bit.

[0038] In 8-bit image encoding scenarios, the non-linear digital grayscale value Gray is an integer ranging from 0 to 255, while the normalized linear optical grayscale value... L∈[0,1], for example only, γ can take the value 2.2.

[0039] Each pixel p includes R sub-pixels, G sub-pixels, and B sub-pixels. The non-linear digital grayscale value of pixel p includes the non-linear digital grayscale value of the R sub-pixels. Nonlinear digital grayscale values ​​of G sub-pixels and the non-linear digital grayscale value of B sub-pixels The normalized linear optical grayscale value of pixel p includes the normalized linear optical grayscale value of sub-pixels R. Normalized linear optical grayscale values ​​of G sub-pixels Normalized linear optical grayscale values ​​of B sub-pixels ;in, ∈[0,1], ∈[0,1], ∈[0,1].

[0040] Normalized luminance stimulus value of pixel p in color space , is the normalized value of the Y component in the tristimulus value vector of pixel p. and These are the remaining two components of the tristimulus value vector of pixel p, namely the E component and the F component. In some embodiments, the transformation relationship between the E component, Y component, and F component of the tristimulus value vector and the CIE1931 color coordinates (x, y) is as follows:

[0041] .

[0042] In some embodiments, the tristimulus value vector of pixel p and the normalized luminance stimulus value of pixel p All of these can be based on the native color gamut conversion matrix M, the normalized linear optical grayscale value of pixel p, and the normalization coefficient of the white point in the native RGB color space. , and Sure, + + =1.

[0043] ;

[0044] , ∈[0,1];

[0045] ;

[0046] , ;

[0047] , .

[0048] in, , , These are the tristimulus value vectors of the original R, G, and B primary colors, respectively. Let be the tristimulus value vector for white, where the Y component equals 1 for unit luminance. As an example only, in some embodiments, the CIE1931 xy color coordinates when the R, G, B, and W channels are individually illuminated are respectively ( , ) = (0.6400, 0.3300), ( , ) = (0.3000, 0.6000), ( , ) = (0.1500, 0.0600), ( , = (0.3127, 0.3290); The normalization factor of the D65 standard white point in the native RGB color space is: =0.2126, =0.7152, =0.0722. In some other embodiments, the CIE1931 xy color coordinates when the R channel, G channel, B channel, and W channel are individually lit can also be other values, and the normalization coefficient of the D65 standard white point in the native RGB color space can also be other values. This application does not limit this.

[0049] In addition to the above method of calculating the normalized linear optical grayscale value and normalized luminance stimulus value of pixel p in real time based on the nonlinear digital grayscale value of pixel p, it is also possible to directly look up the normalized linear optical grayscale value and normalized luminance stimulus value of pixel p in real time based on a pre-established database or table.

[0050] S202, based on the normalized luminance stimulus value, normalized linear optical grayscale value and maximum allowable desaturation condition of each pixel in the target display area, solve for the desaturation coefficient of the target backlight area corresponding to the target display area; the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to be [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel and B channel to be allocated to the W channel.

[0051] The target backlight area can be the entire backlight area or a backlight zone of the backlight module. Each pixel corresponds to a maximum allowable desaturation condition.

[0052] In some embodiments, the maximum allowable desaturation condition for pixel p can be obtained based on the color restoration core equation of pixel p in subfield mode. The color restoration core equation of pixel p in subfield mode is:

[0053] ;

[0054] For example, in the four-player mode, =1, the equation for the Y component of color reproduction is:

[0055] ;

[0056] in, Let p be the tristimulus value vector. , , , These represent the normalized linear transmittance (i.e., normalized linear liquid crystal transmittance) of pixel p under the R, G, B, and W subfields, respectively. , , , These represent the normalized driving luminance values ​​of each red, green, blue, and white light-emitting device within the target backlight region under the R, G, B, and W subfields, respectively. Based on this, constraints are imposed respectively. , , All are greater than or equal to 0 and are respectively constrained , , All values ​​are less than or equal to 1, from which the maximum allowable desaturation condition for pixel p can be obtained.

[0057] The desaturation coefficient controls the proportion of neutral linear luminance synthesized from the R, G, and B channels allocated to the W channel. Specifically, within the target backlight area, when the R, G, and B channels correspond to the same desaturation coefficient k (k∈[0,1]), the tristimulus value vectors of the R, G, and B primary colors are desaturated. , , These can be expressed using the following parameterized formulas:

[0058] ;

[0059] Within the target backlight area, the R channel, G channel, and B channel correspond to the desaturation coefficients of the R channel, respectively. G-channel desaturation coefficient B-channel desaturation coefficient In this case, ∈[0,1], ∈[0,1], ∈[0,1], desaturated tristimulus value vectors of R, G, and B primary colors , , These can be expressed using the following parameterized formulas:

[0060] ;

[0061] In the scheme of this application embodiment, the tristimulus value vector of the desaturated RGB primary color follows the above parameterization formula. It can be seen that the color coordinates always fall on the line connecting the white point color coordinates and the original RGB primary color color coordinates.

[0062] This step calculates the desaturation coefficient of the target backlight region corresponding to the target display region based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display region. This achieves a non-iterative analytical solution for the backlight desaturation coefficient in the color space.

[0063] S203 performs color splitting based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

[0064] In some embodiments, the control module may include an image processing module, a panel driving module, and a backlight driving module. The image processing module is connected to both the panel driving module and the backlight driving module. The panel driving module is connected to the liquid crystal panel, and the backlight driving module is connected to the backlight module. In some embodiments, the image processing module may be used to execute at least a portion of the processes in steps S201 to S203. The backlight driving module may drive and control the target backlight area under different color subfields based on the normalized driving brightness value D of each light-emitting device in the target backlight area under different color subfields. The panel driving module may drive and control the target display area under different color subfields based on the normalized linear transmittance t of each pixel in the target display area under different color subfields. It is understood that the structure of the control module is not limited to this. It may also be in the form of a processor, or the control module may control the operation of the display device and respond to user operations through various software control programs stored in the memory. This application embodiment does not limit this.

[0065] In some embodiments, the normalized driving brightness value D of the light-emitting device can be mapped to a digital signal. In actual driving, the digital signal is used to express the value. For example, based on a pre-established database or table, the normalized driving brightness value D with a value of [0, 1] is mapped to a value of [0, 1023] with 10-bit precision. Each value has a corresponding DC current value and total light emission duration, thereby driving the light-emitting device.

[0066] In some embodiments, the normalized linear transmittance t of a pixel can be converted into a non-linear digital grayscale value through gamma encoding. For example, the conversion can be performed using the following formula: In an 8-bit image encoding scenario, the non-linear digital grayscale value of a physical pixel... γ is the normalized linear transmittance of the pixel, and its value is [0, 1]. As an example only, γ can be 2.2. In some embodiments, the nonlinear digital grayscale value of the physical pixel can also be obtained in real time from a pre-established database or table based on the normalized linear transmittance t of the pixel.

[0067] The solution in this application, within the color space, starts from the color restoration equation and always performs a non-iterative analytical solution for the backlight desaturation coefficient based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of the pixels in the image data of the frame to be displayed. This achieves a non-iterative analytical solution for the backlight desaturation coefficient based on the image data of the frame to be displayed in the color space, thereby improving the efficiency of the desaturation coefficient solution, reducing coefficient errors, and ensuring that the color coordinates of the desaturated RGB primary colors fall on the line connecting the white point color coordinates and the corresponding native RGB primary color coordinates (e.g., but not limited to CIE1931 xy color gamut coordinates or CIE1976 u'v' color gamut coordinates). This improves the defects of color gamut shift and color coordinate drift in related technologies that cause color restoration distortion of input images. At the same time, it helps to improve the defects of large spectral jump amplitude between subfields in related technologies that cause color separation or flickering in moving images, thus achieving image quality improvement and power consumption optimization. The solution in this application embodiment extracts and allocates neutral linear brightness (e.g., white light brightness) based on a determined, reasonable, appropriate, and good desaturation coefficient, thereby optimizing the extraction and allocation of neutral linear brightness and further achieving image quality improvement and power consumption optimization.

[0068] It is understood that the core concept of the solution in this application embodiment includes non-iterative analytical solution of the backlight desaturation coefficient based on the tristimulus values ​​and grayscale values ​​of the pixels in the image data of the frame to be displayed. This ensures that the color coordinates of the desaturated RGB primary colors fall on the line connecting the white point color coordinates and the corresponding native RGB primary color coordinates. The specific content of the maximum allowable desaturation condition can be various, and no specific limitation is made. The following are just examples of a few, but they are not intended to limit the present invention.

[0069] In an exemplary embodiment, where the R channel, G channel, and B channel correspond to the same desaturation coefficient k within the target backlight area, the reference... Figure 3 Step S202 may include the following steps S301 to S303.

[0070] S301, perform mathematical statistical processing on the normalized brightness stimulus values ​​of each pixel in the target display area to obtain the reference value.

[0071] A benchmark value is a numerical value that characterizes the overall level of normalized luminance stimulus values ​​of all pixels within a target display area. It is the result of mathematical statistics on the normalized luminance stimulus values ​​of all pixels within the target display area. The mathematical statistics can be, for example, but not limited to, obtaining the maximum value, the average value, or a weighted sum of the maximum and average values. In other words, in some embodiments, the benchmark value is the maximum value among the normalized luminance stimulus values ​​of all pixels within the target display area; in other embodiments, the benchmark value is the average value of the normalized luminance stimulus values ​​of all pixels within the target display area; and in still other embodiments, the benchmark value is a weighted sum of the maximum value and the average value. The weighting coefficients can be configured as needed based on the actual application scenario. It is understood that there are various methods of mathematical statistics, not limited to those provided above, and can be configured as needed based on the actual application scenario. This application embodiment does not limit this. In some other embodiments, the benchmark value can also be obtained in real-time from a pre-established database or table based on the normalized luminance stimulus values ​​of each pixel within the target display area.

[0072] S302 determines the maximum permissible desaturation value of a pixel based on the reference value, the normalized luminance stimulus value, the normalized linear optical grayscale value, and the maximum permissible desaturation condition of the pixel.

[0073] In some embodiments, step S302 may include the following method:

[0074] ;

[0075] in, This represents the maximum permissible desaturation value for pixel p. , and The normalized linear optical grayscale value of pixel p. This represents the normalized luminance stimulus value for pixel p. This is the baseline value.

[0076] In other embodiments, the maximum allowable desaturation value of a pixel can also be obtained in real time by directly searching the database or table based on the reference value and the normalized luminance stimulus value and normalized linear optical grayscale value of the pixel in the database or table.

[0077] S303, the difference between 1 and the first minimum value is used as the lower limit of the desaturation coefficient of the target backlight area, wherein the upper limit of the desaturation coefficient of the target backlight area is 1, and the first minimum value is the minimum value among the maximum allowable desaturation values ​​of each pixel in the target display area.

[0078] In some embodiments, step S303 may include the following method:

[0079] u= k = 1 - u;

[0080] Where u is the first minimum value and k is the desaturation coefficient; it can be understood that "1-u" in the formula "k=1-u" is the lower limit of the desaturation coefficient of the target backlight area (that is, the minimum value of the desaturation coefficient of the target backlight area that can be calculated), while the upper limit of the desaturation coefficient of the target backlight area is 1 (that is, the maximum value of the desaturation coefficient of the target backlight area). The actual value of the desaturation coefficient k is any value within the range of the lower limit to 1. The specific actual value can be selected as needed based on the actual application scenario. The formula "k=1-u" means that the value of the desaturation coefficient k of the target backlight area is the lower limit of the desaturation coefficient of the target backlight area, that is, the value is the lower limit.

[0081] In other embodiments, the lower limit of the desaturation coefficient of the target backlight area or the desaturation coefficient of the target backlight area can be obtained in real time based on a pre-established database or table, according to the maximum allowable desaturation value of each pixel in the target display area.

[0082] Examples based on steps S301~S303:

[0083] Example 1: The target display area contains only one pixel, let's call it pixel p. This pixel is pure white. Assuming the baseline value is the maximum normalized luminance stimulus value among all pixels in the target display area, then: = = =1, =1, =1, =1, u =1, k=0. Here, the exemplary value of k is the lower limit obtained by solving. The R, G, and B channels are completely turned off, and only the W channel is working, achieving 100% desaturation.

[0084] Example 2: The target display area contains only one pixel, let's call it pixel p. This pixel is a pure red pixel. Assuming the baseline value is the maximum value among the normalized luminance stimulus values ​​of all pixels within the target display area, then: =1、 = =0, =0.2126, =0.2126, =0, u =0, k=1. At this point, the lower limit obtained by the solution has reached 1, which means the upper limit has been reached. k can only take the value 1. The G channel, B channel and W channel are completely turned off, and only the R channel works to meet the high saturation color requirements.

[0085] Example 3: The target display area contains only one pixel, pixel p, which is a mid-gray pixel. Assuming the baseline value is the maximum value among the normalized luminance stimulus values ​​of all pixels in the target display area, then: = = =0.5, =0.5, =0.5, =0.5, u =0.5, k=0.5. Here, k is an example value of the lower limit obtained by solving. The W channel provides half the brightness, and the R, G and B channels provide the other half of the brightness. The total brightness is accurate and the color is not distorted.

[0086] As demonstrated by the mathematical verification above, by solving for the desaturation coefficient, the target tristimulus value of the input pixel can be matched 100%, and the transmittance strictly falls within the range of [0, 1], with no color distortion or risk of exceeding the limit.

[0087] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, B subfield, and W subfield within the period of the image to be displayed (i.e., in the case of four subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area under each different color subfield may include the following method:

[0088] Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is:

[0089] , ∈[0,1];

[0090] Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is:

[0091] , ∈[0,1];

[0092] Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is:

[0093] , ∈[0,1];

[0094] Under the W-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0095] , ∈[0,1].

[0096] In other embodiments, the normalized driving luminance values ​​of each light-emitting device in the target backlight area under different color subfields can be directly retrieved in real time from a pre-established database or table based on the desaturation coefficient and the normalized luminance stimulus values ​​of each pixel in the target display area. In yet another embodiment of the scheme in this application, during the process of determining the normalized driving luminance values ​​of each light-emitting device in the target backlight area under different color subfields, the reference value can also be determined based on the backlight diffusion effect. Make corrections to the baseline value. For example, but not limited to, the total incident backlight brightness at pixel p in the liquid crystal panel. There are various ways to calculate the total incident backlight brightness at pixel p in the liquid crystal panel, and methods known in the art can be used. This application does not limit the method used in its embodiments. Regarding the reference value... The correction makes the normalized driving luminance values ​​of each light-emitting device within the target backlight area more accurate. Furthermore, in determining the normalized driving luminance values ​​of each light-emitting device within the target backlight area under different color subfields, a limiting function can be used to ensure… , , , , + + + Each should not exceed its corresponding limit to avoid hardware overload.

[0097] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to subfields R, G, B, and W within a frame image period (i.e., in the case of four subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized linear transmittance of each pixel in the target display area under each different color subfield may include the following method:

[0098] For example, in the four-field mode, the W field is fully transparent ( =1), the color reproduction Y component equation is:

[0099] ;

[0100] Will and Substituting into the above equation, the independent equation for splitting the R channels using color linear independence is:

[0101] ;

[0102] Divide both sides of the above equation by ,get:

[0103] ;

[0104] Thus, the normalized linear transmittance of pixel p within the target display area under the R subfield is obtained as follows:

[0105] , ∈[0,1];

[0106] Similarly, under the G subfield, the normalized linear transmittance of pixel p within the target display area is obtained as follows:

[0107] , ∈[0,1];

[0108] Similarly, under subfield B, the normalized linear transmittance of pixel p within the target display area is:

[0109] , ∈[0,1];

[0110] In the W subfield, the normalized linear transmittance of each pixel within the target display area is:

[0111] .

[0112] In other embodiments, the normalized linear transmittance of each pixel in the target display area under different color subfields can be obtained in real time by directly searching the database or table based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area in the database or table.

[0113] In some other embodiments, in determining the normalized linear transmittance of each pixel within the target display area under different color subfields, the backlight diffusion effect can also be used to adjust the above-mentioned transmittance. , , The calculation formula has been revised as follows:

[0114] ;

[0115] in, = + + + , It is the total incident backlight brightness at pixel p in the LCD panel. These are the physical location coordinates of pixel p. It is a vector consisting entirely of 1s. , , , These represent the contributions of the R, G, B, and W channels to the incident backlight brightness at pixel p, respectively. These contributions can be calculated using methods known in this technical field (e.g., modeling backlight diffusion characteristics using a two-dimensional PSF matrix from actual system measurements, or theoretically modeling using a two-dimensional Gaussian function). , , , , This application does not limit the method in the embodiments.

[0116] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, and B subfield within the period of the image to be displayed (i.e., in the case of three subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area under each different color subfield may include the following method:

[0117] Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is:

[0118] , ∈[0,1];

[0119] Under the R subfield, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0120] , ∈[0,1];

[0121] Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is:

[0122] , ∈[0,1];

[0123] Under the G-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0124] , ∈[0,1];

[0125] Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is:

[0126] , ∈[0,1];

[0127] Under subfield B, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0128] , ∈[0,1].

[0129] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, and B subfield within the period of the image to be displayed (i.e., in the case of three subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized linear transmittance of each pixel in the target display area under each different color subfield may include the following method:

[0130] Under the R, G, and B subfields, the normalized linear transmittance of pixel p within the target display area is respectively , , ,in, Desaturation primary color transformation matrix:

[0131] ;

[0132] ;

[0133] , .

[0134] In an exemplary embodiment, within the target backlight area, the R channel, G channel, and B channel respectively correspond to the R channel desaturation coefficient. G-channel desaturation coefficient B-channel desaturation coefficient In the case where each pixel includes R sub-pixels, G sub-pixels, and B sub-pixels, let J∈{R, G, B}, refer to Figure 4 Step S202 may include the following steps S401 to S403.

[0135] S401 performs mathematical statistical processing on the normalized luminance stimulus values ​​of each pixel within the target display area to obtain a reference value.

[0136] This step S401 can be referred to the aforementioned step S301.

[0137] S402, based on the reference value, the normalized luminance stimulus value of the pixel, the normalized linear optical grayscale value of the J sub-pixel, and the maximum allowable desaturation condition of the pixel under the J subfield, determine the maximum allowable desaturation value of the pixel under the J subfield; wherein, the maximum allowable desaturation condition of the pixel under the J subfield constrains the normalized linear transmittance of the pixel under the J subfield to be [0, 1].

[0138] In some embodiments, step S402 may include the following method:

[0139] When J=R, the maximum permissible desaturation level of pixel p under subfield R is:

[0140] ;

[0141] When J=G, the maximum permissible desaturation level of pixel p under subfield G is:

[0142] ;

[0143] When J=B, the maximum permissible desaturation level of pixel p under subfield B is:

[0144] ;

[0145] in, , , These are the normalized linear optical grayscale values ​​of the R, G, and B sub-pixels in pixel p, respectively.

[0146] S403, the difference between 1 and the second minimum value is used as the lower limit of the desaturation coefficient of the J channel of the target backlight area, wherein the upper limit of the desaturation coefficient of the J channel of the target backlight area is 1, and the second minimum value is the minimum value among the maximum allowable desaturation values ​​of each pixel under the J subfield in the target display area.

[0147] In some embodiments, step S403 may include the following method:

[0148] = , =1- ;

[0149] = , =1- ;

[0150] = , =1- ;

[0151] in, , , These are different second minimum values; it is understandable that the formula " =1- "1- "This represents the lower limit of the R-channel desaturation coefficient for the target backlight area, while the upper limit of the R-channel desaturation coefficient for the target backlight area is 1, as shown in the formula." =1- "Indicates the desaturation coefficient of the R channel in the target backlight area" The value is the lower limit of the desaturation coefficient of the R channel in the target backlight area, and the desaturation coefficient is... The actual value can be any value within the range of 1 to the lower limit; Formula =1- and =1- Similarly.

[0152] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, B subfield, and W subfield within the period of the image to be displayed (i.e., in the case of four subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area under each different color subfield may include the following method:

[0153] Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is:

[0154] ;

[0155] Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is:

[0156] ;

[0157] Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is:

[0158] ;

[0159] Under the W-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0160] .

[0161] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to subfields R, G, B, and W within a frame image period (i.e., in the case of four subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized linear transmittance of each pixel in the target display area under each different color subfield may include the following method:

[0162] Under the R subfield, the normalized linear transmittance of pixel p within the target display area is:

[0163] ;

[0164] Under the G subfield, the normalized linear transmittance of pixel p within the target display area is:

[0165] ;

[0166] Under subfield B, the normalized linear transmittance of pixel p within the target display area is:

[0167] ;

[0168] Under the W subfield, the normalized linear transmittance of each pixel within the target display area is:

[0169] .

[0170] In some embodiments, during the process of determining the normalized linear transmittance of each pixel within the target display area under different color subfields, the backlight diffusion effect can also be used to adjust the above-mentioned transmittance. , , The calculation formula has been revised as follows:

[0171] ;

[0172] ;

[0173] .

[0174] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, and B subfield within the period of the image to be displayed (i.e., in the case of three subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area under each different color subfield may include the following method:

[0175] Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is:

[0176] ;

[0177] Under the R subfield, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0178] ;

[0179] Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is:

[0180] ;

[0181] Under the G-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0182] ;

[0183] Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is:

[0184] ;

[0185] Under subfield B, the normalized driving luminance value of each white light-emitting device in the target backlight area is:

[0186] .

[0187] In some embodiments, when the liquid crystal panel is configured to sequentially display images corresponding to the R subfield, G subfield, and B subfield within the period of the image to be displayed (i.e., in the case of three subfields), the color splitting process in step 203 based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized linear transmittance of each pixel in the target display area under each different color subfield may include the following method:

[0188] Under the R, G, and B subfields, the normalized linear transmittance of pixel p within the target display area is respectively , , :

[0189] ;

[0190] ;

[0191] , .

[0192] This application also provides a backlight control method applied to the display device provided in any of the above embodiments. The display device includes at least a liquid crystal panel and a backlight module. The liquid crystal panel is configured to sequentially display images corresponding to multiple subfields within a single frame image period. The backlight control method can be executed by a control module in the display device. The backlight control method includes:

[0193] The nonlinear digital grayscale values ​​of pixels within the target display area in the image data of the display frame are subjected to gamma conversion to determine the normalized linear optical grayscale values ​​of the pixels, and the normalized luminance stimulus values ​​of the pixels in the color space are determined based on the normalized linear optical grayscale values ​​of the pixels.

[0194] Based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved; where the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to take the value of [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel, and B channel allocated to the W channel;

[0195] Color splitting is performed based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

[0196] The backlight control method and display device provided in the embodiments of this application belong to the same inventive concept, can solve the same technical problem, and thus achieve the same technical effect. Repeated content will not be repeated here.

[0197] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the accompanying drawings may include multiple steps or stages, which are not necessarily completed at the same time, but may be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0198] It is understood that the display device in the embodiments of this application can be any product or component with display function, such as a liquid crystal display device, electronic paper, mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, navigator, wearable device, Internet of Things device, etc., and the embodiments disclosed in this application do not limit this.

[0199] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0200] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A display device, characterized in that, It includes a liquid crystal panel, a backlight module, and a control module, wherein the liquid crystal panel is configured to sequentially display images corresponding to multiple subfields within a single frame image period; The control module is configured as follows: The nonlinear digital grayscale values ​​of pixels within the target display area in the image data of the display frame are subjected to gamma conversion to determine the normalized linear optical grayscale values ​​of the pixels, and the normalized luminance stimulus values ​​of the pixels in the color space are determined based on the normalized linear optical grayscale values ​​of the pixels. Based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved; where the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to take the value of [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel, and B channel allocated to the W channel; Color splitting is performed based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

2. The display device according to claim 1, characterized in that, Within the target backlight area, the R channel, G channel, and B channel correspond to the same desaturation coefficient; The method of calculating the desaturation coefficient of the target backlight region corresponding to the target display region based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel within the target display region includes: The normalized luminance stimulus values ​​of each pixel within the target display area are mathematically statistically processed to obtain the baseline value; Based on the reference value, the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of the pixel, the maximum allowable desaturation value of the pixel is determined. The difference between 1 and the first minimum value is used as the lower limit of the desaturation coefficient of the target backlight area, where the upper limit of the desaturation coefficient of the target backlight area is 1, and the first minimum value is the minimum value among the maximum allowable desaturation values ​​of each pixel in the target display area.

3. The display device according to claim 2, characterized in that, The determination of the maximum permissible desaturation value of a pixel based on a reference value, the pixel's normalized luminance stimulus value, normalized linear optical grayscale value, and the maximum permissible desaturation condition includes: ； in, This represents the maximum permissible desaturation value for pixel p. , and The normalized linear optical grayscale value of pixel p. This represents the normalized luminance stimulus value for pixel p. This is the baseline value.

4. The display device according to claim 2 or 3, characterized in that, The color splitting process based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area, to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, includes: Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is: ； Under the W-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the R subfield, the normalized linear transmittance of pixel p within the target display area is: ； Under the G subfield, the normalized linear transmittance of pixel p within the target display area is: ； Under subfield B, the normalized linear transmittance of pixel p within the target display area is: ； Under the W subfield, the normalized linear transmittance of each pixel within the target display area is: ； Where k is the desaturation coefficient. , and This represents the normalization coefficient of the white point in the native RGB color space. As the baseline value, , and The normalized linear optical grayscale value of pixel p. is the normalized luminance stimulus value for pixel p.

5. The display device according to claim 2 or 3, characterized in that, The color splitting process based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area, to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, includes: Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is: ； Under the R subfield, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the R, G, and B subfields, the normalized linear transmittance of pixel p within the target display area is respectively , , : ； ， ； Where k is the desaturation coefficient. , and This represents the normalization coefficient of the white point in the native RGB color space. As the baseline value, Let p be the tristimulus value vector. , , , These are the tristimulus value vectors for the R, G, B, and W channels under unit brightness, respectively. , , These are the tristimulus value vectors for desaturated R primary color, desaturated G primary color, and desaturated B primary color, respectively. This is the desaturation primary color transformation matrix.

6. The display device according to claim 1, characterized in that, Within the target backlight area, the R channel, G channel, and B channel do not correspond to the same desaturation coefficient. Specifically, the R channel, G channel, and B channel correspond to the R channel desaturation coefficient, G channel desaturation coefficient, and B channel desaturation coefficient, respectively. Each pixel includes an R sub-pixel, a G sub-pixel, and a B sub-pixel; Let J∈{R, G, B}; The method of calculating the desaturation coefficient of the target backlight region corresponding to the target display region based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel within the target display region includes: The normalized luminance stimulus values ​​of each pixel within the target display area are mathematically statistically processed to obtain the baseline value; Based on the reference value, the normalized luminance stimulus value of the pixel, the normalized linear optical grayscale value of the J sub-pixel, and the maximum allowable desaturation condition of the pixel under the J subfield, the maximum allowable desaturation value of the pixel under the J subfield is determined; wherein, the maximum allowable desaturation condition of the pixel under the J subfield constrains the normalized linear transmittance of the pixel under the J subfield to be [0, 1]. The difference between 1 and the second minimum value is used as the lower limit of the desaturation coefficient of the J channel in the target backlight area. The upper limit of the desaturation coefficient of the J channel in the target backlight area is 1, and the second minimum value is the minimum value among the maximum allowable desaturation values ​​of each pixel under the J subfield in the target display area.

7. The display device according to claim 6, characterized in that, The determination of the maximum permissible desaturation value of a pixel under the J-field, based on the reference value, the normalized luminance stimulus value of the pixel, the normalized linear optical grayscale value of the J-sub-pixel, and the maximum permissible desaturation condition of the pixel under the J-field, includes: When J=R, the maximum permissible desaturation level of pixel p under subfield R is: ； When J=G, the maximum permissible desaturation level of pixel p under subfield G is: ； When J=B, the maximum permissible desaturation level of pixel p under subfield B is: ； in, , , These are the normalized linear optical grayscale values ​​of the R, G, and B sub-pixels in pixel p, respectively. This represents the normalized luminance stimulus value for pixel p. This is the baseline value.

8. The display device according to claim 6 or 7, characterized in that, The color splitting process based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area, to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, includes: Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is: ； Under the W-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the R subfield, the normalized linear transmittance of pixel p within the target display area is: ； Under the G subfield, the normalized linear transmittance of pixel p within the target display area is: ； Under subfield B, the normalized linear transmittance of pixel p within the target display area is: ； Under the W subfield, the normalized linear transmittance of each pixel within the target display area is: ； in, , , These are the desaturation coefficients for the R channel, G channel, and B channel, respectively. , and This represents the normalization coefficient of the white point in the native RGB color space. As the baseline value, , , These are the normalized linear optical grayscale values ​​for the R, G, and B sub-pixels, respectively. is the normalized luminance stimulus value for pixel p.

9. The display device according to claim 6 or 7, characterized in that, The color splitting process based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area, to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, includes: Under the R subfield, the normalized driving luminance value of each red light-emitting device in the target backlight area is: ； Under the R subfield, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each green light-emitting device in the target backlight area is: ； Under the G-field, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each blue light-emitting device in the target backlight area is: ； Under subfield B, the normalized driving luminance value of each white light-emitting device in the target backlight area is: ； Under the R, G, and B subfields, the normalized linear transmittance of pixel p within the target display area is respectively , , : ； ， ； in, , , These are the desaturation coefficients for the R channel, G channel, and B channel, respectively. , and This represents the normalization coefficient of the white point in the native RGB color space. As the baseline value, Let p be the tristimulus value vector. , , , These are the tristimulus value vectors for the R, G, B, and W channels under unit brightness, respectively. , , These are the tristimulus value vectors for desaturated R primary color, desaturated G primary color, and desaturated B primary color, respectively. This is the desaturation primary color transformation matrix.

10. A backlight control method applied to a display device, the display device comprising at least a liquid crystal panel and a backlight module, the liquid crystal panel being configured to sequentially display images corresponding to multiple subfields within a single frame image period, characterized in that... The method includes: The nonlinear digital grayscale values ​​of pixels within the target display area in the image data of the display frame are subjected to gamma conversion to determine the normalized linear optical grayscale values ​​of the pixels, and the normalized luminance stimulus values ​​of the pixels in the color space are determined based on the normalized linear optical grayscale values ​​of the pixels. Based on the normalized luminance stimulus value, normalized linear optical grayscale value, and maximum allowable desaturation condition of each pixel in the target display area, the desaturation coefficient of the target backlight area corresponding to the target display area is solved; where the maximum allowable desaturation condition of the pixel constrains the normalized linear transmittance of the pixel under different color subfields to take the value of [0, 1]; the desaturation coefficient is a dimensionless coefficient with a value of [0, 1], used to control the proportion of neutral linear luminance synthesized by the R channel, G channel, and B channel allocated to the W channel; Color splitting is performed based on the desaturation coefficient and the normalized luminance stimulus value of each pixel in the target display area to determine the normalized driving luminance value of each light-emitting device in the target backlight area and the normalized linear transmittance of each pixel in the target display area under different color subfields, so as to drive and control the target backlight area and the target display area.

Images