Method for solving color deviation of three-color mini-led backlight liquid crystal display device and liquid crystal display device

Abstract

The application discloses a method for solving color deviation of a three-color Mini LED backlight liquid crystal display device and a liquid crystal display device, and relates to the technical field of liquid crystal display, and comprises the following steps: adjusting RGB backlight currents of a white field, recording a set of RGB backlight current ratios when color coordinates of the white color reach design target values; adjusting RGB backlight currents of red, green and blue single-color fields respectively, recording a second set of RGB backlight current ratios, so that the RGB synthesis obtains the design target values, and obtaining coordinate points W, R, G and B of the white color, the red color, the green color and the blue color on a CIE chromaticity diagram respectively; performing segmentation processing on a to-be-displayed image, counting average image color coordinates of each block as to-be-displayed colors, obtaining a coordinate point C of the to-be-displayed colors on the CIE chromaticity diagram, and calculating RGB current values of backlight of the block according to relative positions of C, R, G, B and W and the two sets of RGB backlight current ratios. The application can guarantee a color gamut and solve the color deviation phenomenon.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal display technology, specifically, to a method for solving color distortion in a three-color MiniLED backlit liquid crystal display device and a liquid crystal display device thereof. Background Technology

[0002] With the popularization of MiniLED technology and products, further upgrades to MiniLED technology have begun to emerge in the market: tri-color backlighting, which includes RGB backlighting and BGB backlighting. BGB backlighting offers better cost-effectiveness, but because it uses a solution of blue chips and red phosphors for red, the emitted light is magenta rather than true red, leading to color shift when synthesizing some colors. To solve this problem, some existing technologies synthesize the backlight entirely into white light to prevent color shift, but this loses the color gamut improvement advantage brought by independent light control of the three colors. Summary of the Invention

[0003] The purpose of this invention is to provide a method and a liquid crystal display device for solving color deviation in a three-color MiniLED backlight liquid crystal display device. This method addresses the problem in the prior art where the backlight is completely synthesized into white light to prevent BGB backlight color deviation, thus losing the color gamut enhancement technology advantage brought by independent light control of the three-color backlight.

[0004] The present invention solves the above problems through the following technical solution:

[0005] A method for solving color distortion in a three-color MiniLED backlit LCD display device includes:

[0006] Adjust the RGB backlight current of the white field to make the chromaticity coordinates of white reach the design target value, record the first set of RGB backlight current ratios: R1:G1:B1, and obtain the coordinate point W of white in the CIE chromaticity diagram;

[0007] The RGB backlight currents of the three monochromatic fields (red, green, and blue) are adjusted separately, and the second set of RGB backlight current ratios (R2:G2:B2) is recorded so that the RGB synthesis yields the design target value. The coordinates of red, green, and blue in the CIE chromaticity diagram are obtained respectively.

[0008] The image to be displayed is segmented, and the following steps are performed on each segment:

[0009] The average color coordinates are used as the color to be displayed. The coordinate point C of the color to be displayed in the CIE chromaticity diagram is obtained. Based on the relative positions of coordinate points C, R, G, B and W in the CIE chromaticity diagram, and combined with the first group of RGB backlight current ratios and the second group of RGB backlight current ratios, the RGB current value of the backlight of the block is calculated.

[0010] In this invention, a first set of RGB backlight current ratios is obtained by synthesizing white light with all RGB lights on, and a second set of RGB backlight current ratios is obtained by theoretically synthesizing white light from individual RGB lights. By calculating the data for each region, the color to be displayed in that region is obtained, thus determining the relative relationship between the color to be displayed (C) and the four colors WRGB. This allows for the determination of which of the two sets of RGB backlight current ratios is closest to the desired color (C). Furthermore, using the two sets of RGB ratios as the basis for calculation and quantification, a specific RGB backlight current is obtained, ensuring that the RGB brightness required for synthesizing various colors is normal. This solves the problem of color shift in some colors in BGB backlight technology and guarantees the color gamut.

[0011] The existing method of completely synthesizing backlight into white light to prevent color cast works by using white backlight for any color displayed on the screen. This is equivalent to traditional backlight products, naturally avoiding color cast. However, the RGB ratio is fixed, and it lacks independent control of the three backlight colors. Because any single color is mixed with a large number of other colors, its color purity is low, failing to leverage the advantages of RGB backlighting. Independent control of three colors is a common and fundamental approach in RGB technology. This invention differs from existing methods that completely synthesize backlight into white light. Instead, it dynamically adjusts the backlight color by analyzing the color components of the image, matching the image colors and reducing the influence of other colors on the displayed color. Therefore, it still retains the color gamut enhancement advantages of the independent control of three colors in the RGB solution.

[0012] Furthermore, adjusting the RGB backlight current of the white field to achieve the designed target value for the white color coordinates, and recording the first set of RGB backlight current ratios: R1:G1:B1, specifically includes:

[0013] Control all RGB pixels of the LCD screen to be fully turned on, adjust the current ratio of the RGB three-color backlight so that the color coordinate of white reaches the design target value, i.e., the target white, and record the RGB backlight current ratio at this time as R1:G1:B1.

[0014] This step synthesizes white light with all RGB lights on to obtain a set of RGB current ratios. Its purpose is to: 1) compare with the second set of RGB current ratios obtained by theoretically synthesizing white light from RGB lights emitting light separately, and determine which set is closer to the current ratio required for the corresponding color C to be displayed after subsequent image segmentation and calculation of data for each region; 2) use the second set of RGB current ratios together as basic data for calculation and quantization to obtain specific RGB currents, ensuring that the RGB brightness required for synthesizing various colors is normal brightness.

[0015] Furthermore, the step of separately adjusting the RGB backlight current of the three monochromatic fields (red, green, and blue) and recording the second set of RGB backlight current ratios: R2:G2:B2, so that the RGB synthesis yields the design target value, and obtaining the coordinates R, G, and B of red, green, and blue on the CIE chromaticity diagram, specifically includes:

[0016] The red, green, and blue pixels of the LCD screen are each controlled to be fully turned on while the other two are turned off. The current of the fully turned-on color backlight is adjusted to make the LCD screen display the corresponding color. The red brightness Lv-R, green brightness Lv-G, and blue brightness Lv-B, as well as the corresponding coordinate points R, G, and B in the CIE chromaticity diagram, are obtained. The RGB three-color brightness ratio is determined according to the design target value, and Lv-R:Lv-G:Lv-B is adjusted to the RGB three-color brightness ratio. The RGB backlight current ratio at this time is recorded as R2:G2:B2.

[0017] It is worth noting that the steps for obtaining the first set of RGB backlight current ratios and the second set of RGB backlight current ratios can be interchanged.

[0018] Furthermore, in the process of adjusting Lv-R:Lv-G:Lv-B to the RGB three-color brightness ratio, the G current is treated as a fixed value, i.e., G1=G2.

[0019] Furthermore, the method for calculating the RGB current value of the backlight in this block based on the relative positions of coordinate points C, R, G, B, and W in the CIE chromaticity diagram, combined with the first set of RGB backlight current ratios and the second set of RGB backlight current ratios, includes:

[0020] Connect the coordinates R, G, B, W, and C of the obtained red, green, blue, white, and the color to be displayed in this block on the CIE chromaticity diagram, and extend WC to intersect BG at point D; thus obtaining the RGB current value of the backlight for this block:

[0021] R3=CD / DW*R1+CW / DW*0, G3=G2=G1, B3=CD / DW*B1+CW / DW*B2.

[0022] Furthermore, the CIE chromaticity diagram adopts CIE1931 or CIE1976.

[0023] Furthermore, it also includes creating a lookup table by matching different colors to be displayed with their corresponding backlight current ratios, in order to quickly retrieve data and improve operating efficiency.

[0024] A liquid crystal display device for implementing the method of solving color deviation in a three-color MiniLED backlit liquid crystal display device includes a main control chip, a driver module, a backlight module with three-color LED strips, and a liquid crystal display screen, wherein:

[0025] The main control chip is used to segment the image to be displayed, calculate the average color coordinates of each block of the image, and obtain the corresponding RGB current value of the backlight; and to control the backlight driving current of the driving module to control the brightness of the liquid crystal display screen. The more image segments there are, the more accurate the backlight color control is, and the higher the computing power requirement of the main control chip. When using a lookup table solution, the display device no longer needs to perform real-time calculations, which can significantly reduce the computing power requirement and improve the operating efficiency.

[0026] The driving module is used to connect the main control chip and the tri-color LED strip of the backlight module, and convert the backlight driving command output by the main control chip into current to drive the LEDs of the tri-color LED strip of the backlight module to emit light.

[0027] A three-color LED strip is installed on the LCD screen to emit red, green, and blue light for display.

[0028] Furthermore, the system employs two main control chips. One chip controls the backlight driving current of the driving module to control the brightness of the LCD screen, while the other chip segments the image to be displayed, calculates the average color coordinates of each image block, and obtains the corresponding RGB current value of the backlight. Using two main control chips enables independent control and improves computing power.

[0029] Furthermore, the main control chip is also used to form a lookup table by matching different colors to be displayed with their corresponding backlight current ratios, so as to quickly retrieve data.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] This invention obtains two sets of RGB current ratios for the white field and the red, green and blue monochromatic fields, and then performs block segmentation and calculation on the image content to obtain the average color of each block as the color to be displayed. Then, based on the relative positions of the five colors (red, green, blue and white) in the CIE chromaticity diagram and the two sets of RGB current ratios, the RGB current ratio of the block is calculated, which can both guarantee the color gamut and solve the color cast problem. Attached Figure Description

[0032] Figure 1 This is a system block diagram of a three-color MiniLED backlit liquid crystal display device in an embodiment of the present invention;

[0033] Figure 2 This is a CIE1931 chromaticity diagram in an embodiment of the present invention;

[0034] Among them, 101-main control chip; 102-drive module; 103-backlight module tri-color LED strip; 104-LCD display screen. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0036] This invention provides a method for solving color shift in a three-color MiniLED backlit liquid crystal display device, wherein, as shown in the embodiments of the present invention... Figure 1 As shown, the tri-color MiniLED backlit LCD display device mainly consists of the following parts: a main control chip 101 is responsible for all signal processing for the backlight / LCD screen, a drive module 102 is responsible for converting the backlight control signal issued by the main control chip 101 into current to drive the LEDs to emit light, a tri-color LED strip 103 in the backlight module serves as the tri-color backlight source, and an LCD screen 104 displays images by controlling the LCD to switch on and off via the main control chip 101. The method includes:

[0037] 1) The main control chip 101 controls all RGB pixels of the LCD screen 104 to be fully turned on. The drive module 102 adjusts the current ratio of the RGB three-color backlight, and the three-color LED strips 103 of the backlight module emit light according to the given current, so that the white color coordinate displayed on the LCD screen 104 reaches the design target value. In this embodiment of the invention, 0.280 and 0.290 are used as design target values ​​for illustration. The RGB current ratio at this time is recorded as R1:G1:B1. This white coordinate is... Figure 2 It falls to point W.

[0038] 2) The main control chip 101 controls the red (R) pixel of the LCD screen 10 to be fully turned on, while the green (G) and blue (B) pixels are turned off. The drive module 102 adjusts the current of the R backlight so that the red brightness displayed on the LCD screen 104 is Lv-R; this red coordinate is... Figure 2 It falls to point R.

[0039] 3) Repeat step 2) for both green (G) and blue (B) to make the displayed green brightness Lv-G and the blue brightness Lv-B; green (G) and blue (B) in Figure 2 The landing points are G and B, respectively.

[0040] 4) Based on the design target values ​​of 0.280 and 0.290 for this LCD display device, the RGB brightness ratio R:G:B can be determined to be approximately 2:1:8. When Lv-R:Lv-G:Lv-B is adjusted to 2:1:8, the RGB current ratio at this time is recorded as R2:G2:B2. This can be understood as fixing one color and adjusting the other two colors to achieve a 2:1:8 ratio. Since color G is not affected by colors R and B, the current G is treated as a fixed value, i.e., G1 = G2.

[0041] 5) When the LCD display device is working, the main control chip 101 processes the image content and divides it into X*Y regions. In this embodiment, 2*3=6 regions are used for illustration. In actual design, the number of regions is usually equal to the number of backlight LED zones. Taking the first region as an example, the RGB color components in this region are counted to calculate the average color of this region as the color to be displayed. From this, the coordinates of the color to be displayed in the CIE chromaticity diagram can be obtained, falling on... Figure 2 Point C in the diagram. By calculating the relative position of this coordinate with the color coordinates of the four RGBW colors, the RGB backlight current ratio for that region is determined. It is evident that the more regions segmented, the more precise the backlight color control, and consequently, the higher the computational requirements of the main control chip 101.

[0042] Furthermore, the calculation logic for color in step 5) will be explained further. Figure 2 In the process, based on the five determined points R, G, B, W, and C, connect these points and extend WC to intersect BG at point D. When the desired display color is W, the required current is R1:G1:B1. When the desired display color is monochrome RGB, the corresponding current is R2:G2:B2. The difference between the two is that B2 is significantly higher than B1 because R1 contains a blue component. Therefore, the blue brightness already contained in R1 needs to be subtracted from the normal required brightness of B in B1. Figure 2 In step 5), after calculating the position of point C, color C is considered to be a composite of three colors W, B, and G, where W is composed of R1G1B1, B is composed of B2, and G is composed of G2. Therefore, the closer C is to W, the closer R is to R1; the closer C is to D, the closer R is to 0. Thus:

[0043] R3=CD / DW*R1+CW / DW*0, G3=G2=G1, B3=CD / DW*B1+CW / DW*B2.

[0044] The color cast in existing technologies stems from the fact that BGB three-color display technology uses a solution of a blue chip and red phosphor for red, resulting in magenta light rather than pure red. This color cast occurs during the synthesis of certain colors. When synthesizing white light from the RGB primary colors, the RGB ratio required to achieve the design target value is fixed. Since R, as mentioned above, excites red phosphor with blue, it contains a certain amount of blue. Therefore, the required pure blue B luminance (corresponding to current) needs to be significantly reduced. However, when synthesizing cyan (from B and G), because it lacks red components, it also lacks the B component contained within red. Therefore, using traditional methods, B and G cannot properly synthesize cyan, resulting in a greenish tint.

[0045] The principle behind this invention for solving color cast is as follows: First, a set of RGB current ratios is obtained by synthesizing white light using all RGB lights. Second, a second set of RGB current ratios is obtained by theoretically synthesizing white light using RGB lights emitted individually. The desired display color for each region is calculated based on the data from each region, thus obtaining the relative relationship between the desired display color C and the four WRGB colors (i.e., in...). Figure 2 The relative position in the equation is used to determine the current ratio required for color C, which of the two RGB ratios is closer to. Further calculations and quantifications are performed based on the two RGB ratios to obtain the specific RGB current, ensuring that the RGB brightness required for synthesizing various colors is normal.

[0046] Preferably, there are two main control chips 101. One main control chip 101 controls the backlight driving current of the driving module 102 to control the brightness of the liquid crystal display screen 104. The other main control chip 101 performs segmentation processing on the image to be displayed, calculates the average color coordinates of each block image, and obtains the corresponding RGB current value of the backlight.

[0047] Preferably, the main control chip 101 is also used to form a lookup table by matching different colors to be displayed with their corresponding backlight current ratios, so as to quickly retrieve data.

[0048] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can devise many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A method for solving color shift in a three-color MiniLED backlit liquid crystal display device, characterized in that, include: Adjust the RGB backlight current of the white field to make the chromaticity coordinates of white reach the design target value, record the first set of RGB backlight current ratios: R1:G1:B1, and obtain the coordinate point W of white in the CIE chromaticity diagram; The RGB backlight currents of the three monochromatic fields (red, green, and blue) are adjusted separately, and the second set of RGB backlight current ratios (R2:G2:B2) is recorded so that the RGB synthesis yields the design target value. The coordinates of red, green, and blue in the CIE chromaticity diagram are obtained respectively. The image to be displayed is segmented, and the following steps are performed on each segment: The average color coordinates are used as the color to be displayed. The coordinate point C of the color to be displayed in the CIE chromaticity diagram is obtained. Based on the relative positions of coordinate points C, R, G, B and W in the CIE chromaticity diagram, and combined with the first group of RGB backlight current ratios and the second group of RGB backlight current ratios, the RGB current value of the backlight of the block is calculated.

2. The method for solving color shift in a three-color MiniLED backlit liquid crystal display device according to claim 1, characterized in that, The adjustment of the RGB backlight current of the white field to achieve the design target value for the white color coordinates, and the recording of the first set of RGB backlight current ratios: R1:G1:B1, specifically includes: Control all RGB pixels of the LCD screen to be fully turned on, adjust the current ratio of the RGB three-color backlight so that the color coordinate of white reaches the design target value, i.e., the target white, and record the RGB backlight current ratio at this time as R1:G1:B1.

3. The method for solving color shift in a three-color MiniLED backlit liquid crystal display device according to claim 1, characterized in that, The process of individually adjusting the RGB backlight current of the three monochromatic fields (red, green, and blue), recording the second set of RGB backlight current ratios (R2:G2:B2), and obtaining the design target value after RGB synthesis, specifically involves acquiring the coordinates R, G, and B of red, green, and blue on the CIE chromaticity diagram: The red, green, and blue pixels of the LCD screen are each controlled to be fully turned on while the other two are turned off. The current of the fully turned-on color backlight is adjusted to make the LCD screen display the corresponding color. The red brightness Lv-R, green brightness Lv-G, and blue brightness Lv-B, as well as the corresponding coordinate points R, G, and B in the CIE chromaticity diagram, are obtained. The RGB three-color brightness ratio is determined according to the design target value, and Lv-R:Lv-G:Lv-B is adjusted to the RGB three-color brightness ratio. The RGB backlight current ratio at this time is recorded as R2:G2:B2.

4. The method for solving color shift in a three-color MiniLED backlit liquid crystal display device according to claim 3, characterized in that, In the process of adjusting Lv-R:Lv-G:Lv-B to the RGB three-color brightness ratio, the G current is treated as a fixed value, that is, G1=G2.

5. The method for solving color distortion in a three-color MiniLED backlit liquid crystal display device according to claim 1, characterized in that, The method for calculating the RGB current value of the backlight in this block based on the relative positions of coordinate points C, R, G, B, and W in the CIE chromaticity diagram, combined with the first set of RGB backlight current ratios and the second set of RGB backlight current ratios, includes: Connect the coordinates R, G, B, W, and C of the obtained red, green, blue, white, and the color to be displayed in this block on the CIE chromaticity diagram, and extend WC to intersect BG at point D; thus obtaining the RGB current value of the backlight for this block: R3=CD / DW*R1+CW / DW*0, G3=G2=G1, B3=CD / DW*B1+CW / DW*B2.

6. The method for solving color distortion in a three-color MiniLED backlit liquid crystal display device according to claim 1, characterized in that, The CIE chromaticity diagram used is either CIE1931 or CIE1976.

7. The method for solving color shift in a three-color MiniLED backlit liquid crystal display device according to claim 1, characterized in that, It also includes creating a lookup table that matches different colors to be displayed with their corresponding backlight current ratios, so as to quickly retrieve the data.

8. A liquid crystal display device that implements the method for solving color distortion in a three-color MiniLED backlit liquid crystal display device as described in any one of claims 1-7, characterized in that, It includes a main control chip, a driver module, a backlight module with tri-color LED strips, and an LCD screen, among which: The main control chip is used to segment the image to be displayed, calculate the average color coordinates of each block of the image, and obtain the corresponding RGB current value of the backlight; and to control the backlight driving current of the driving module to control the brightness of the liquid crystal display screen. The driving module is used to connect the main control chip and the tri-color LED strip of the backlight module, and convert the backlight driving command output by the main control chip into current to drive the LEDs of the tri-color LED strip of the backlight module to emit light. A three-color LED strip is installed on the LCD screen to emit red, green, and blue light for display.

9. The liquid crystal display device according to claim 8, characterized in that, There are two main control chips. One main control chip controls the backlight driving current of the driving module to control the brightness of the liquid crystal display screen. The other main control chip performs segmentation processing on the image to be displayed, calculates the average color coordinates of each block of the image, and obtains the corresponding RGB current value of the backlight.

10. The liquid crystal display device according to claim 8, characterized in that, The main control chip is also used to form a lookup table by matching different colors to be displayed with their corresponding backlight current ratios, so as to quickly retrieve data.

Images