This application claims priority to and the benefit of Chinese Patent Application No. 202311301854.9, filed on Oct. 9, 2023, the disclosure of which is incorporated herein by reference in its entirety.
The present disclosure relates to the field of display technologies, and more particularly, to a liquid crystal display panel and a compensation method thereof.
The liquid crystal display panel is driven by alternating currents. Since input signals of positive half-cycles and negative half-cycles are affected by feed-through voltages, liquid crystal clamp voltages during the positive half-cycles and the negative half-cycles are caused to be different, which leads to different screen luminance. Thus, there exists flicker phenomena.
The above flicker is generally adjusted using a fixed pattern. A flicker value is measured by a respective optical instrument. This process usually requires stepwise approximation from several times of “common voltage adjustment—flicker value measurement”. For example, the dichotomy employed in the related art requires about eight times of iterations to obtain a desired flicker value, which leads to the problem that flicker adjustments require multiple iterations.
In a first aspect, the present disclosure provides a compensation method for a liquid crystal display panel including a plurality of pixel cells arranged in an array, each pixel cell including a plurality of sub-pixels having alternating polarities in a row direction and a column direction. The compensation method includes acquiring a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data, every two adjacent pixel cells of the plurality of pixel cells each having a single opposite polarity in one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data, and the plurality of pixel cells displaying a black picture in another one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data; determining a minimum grayscale difference between every adjacent pixel cells based on one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data; determining a gamma voltage difference corresponding to the grayscale difference according to a curve of a relation between grayscales and gamma voltages; and obtaining a correction value for a common voltage based on the gamma voltage difference.
In a second aspect, the present disclosure provides a liquid crystal display panel that performs a compensation method, where the liquid crystal display panel includes a plurality of pixel cells arranged in an array, each pixel cell including a plurality of sub-pixels having alternating polarities in a row direction and a column direction, the compensation method including: acquiring a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data, every two adjacent pixel cells of the plurality of pixel cells each having a single opposite polarity in one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data, and the plurality of pixel cells displaying a black picture in another one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data; determining a minimum grayscale difference between every adjacent pixel cells based on one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data; determining a gamma voltage difference corresponding to the grayscale difference according to a curve of a relation between grayscales and gamma voltages; and obtaining a correction value for a common voltage based on the gamma voltage difference.
The technical solution and other beneficial effects of the present disclosure will be apparent from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.
The technical solution in the embodiments of the present disclosure will be clearly and completely described with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present disclosure.
Furthermore, the terms “first” and “second” are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features, such that the features defining with “first” and “second” may explicitly or implicitly include one or more of the recited features. In the description of the present disclosure, “a plurality of” is meant to mean two or more unless expressly and specifically defined otherwise.
Since a liquid crystal display panel is driven by alternating currents, the input signals of the positive half-cycles and the negative half-cycles are affected by the feed-through voltages, so that the liquid crystal clamp voltages during the positive half-cycles and the negative half-cycles are caused to be different, which leads to different screen luminance. Thus, there exists flicker phenomena.
Therefore, by adopting the adjustment of common voltage (VCOM) as shown in the left figure of
The adjustment of the flicker value is in fact to find a common voltage to minimize the flicker value (a valley of a curve), as shown in the right figure in
The adjustment of the flicker value is generally performed using a fixed flicker pattern for flicker value adjustment as shown in
The sub-pixel arrangement shown in
The measurement of the flicker value is accomplished by a camera model CA310 or other optical instruments that support flicker value measurement. Specifically,
However, with the above method, a minimum flicker value cannot be obtained by adjusting the common voltage at one time, and this process usually requires stepwise approximation from several times of “common voltage adjustment—flicker value measurement”. The dichotomy currently employed requires about eight times of iterations to obtain a small flicker value.
Therefore, in view of the above-mentioned technical problem that adjustment of the flicker value requires multiple iterations, the present embodiment provides a liquid crystal display panel. Referring to
As shown in
At step S10, a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data is acquired. Every two adjacent pixel cells of the plurality of pixel cells each have a single opposite polarity in one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data. The plurality of pixel cells displays a black picture in another one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data.
At step S20, a minimum grayscale difference between every adjacent pixel cells is determined based on one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data.
At step S30, a gamma voltage difference corresponding to the grayscale difference is determined according to a curve of a relation between grayscales and gamma voltages.
At step S40, a correction value of the common voltage is obtained based on the gamma voltage difference.
It will be appreciated that according to the compensation method of the present embodiment, a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data is acquired in the first place, with every two adjacent pixel cells of a plurality of pixel cells each having a single opposite polarity in one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data, and the plurality of pixel cells displaying a black picture in another one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data. A minimum grayscale difference between every adjacent pixel cells is determined based on one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data. Then, a gamma voltage difference corresponding to the grayscale difference is determined according to a curve of a relation between grayscales and gamma voltages, followed by obtaining a correction value for a common voltage based on the gamma voltage difference. A flicker phenomenon can be improved by adjusting the common voltage only once through the correction value without requiring multiple iterations with low efficiency.
Also, the improvement in flicker can also be accomplished by dynamic pictures such as a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data, which extends types of flicker pattern required to adjust the flicker, as compared to the case where flicker is generally adjusted using a fixed flicker pattern.
Also, a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data can be acquired by one shot of a camera. A corresponding grayscale difference that can be identified based on the odd-numbered frame grayscale data and even-numbered frame grayscale data is used as a basis for determining the magnitude of a flicker value, which reduces the frequency of usage of an optical instrument compared with the conventional way in which the flicker value is measured by the corresponding optical instrument, thereby improving the efficiency of flicker adjustment.
It should be noted that in the present embodiment, the flicker value can be reduced by adjusting the common voltage only once without requiring multiple iterations with low efficiency, which improves the adjustment efficiency and further facilitates the improvement of production capacity of the liquid crystal display panel per unit time.
The plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data is shown in
The plurality of pixel cells arranged in an array may be located in a middle region or a central region of the liquid crystal display panel as shown in
In
As can be seen from
Specifically,
It should be noted that the pixel cells shown in settings A and B are described by using only the sub-pixels of 4*4 as an example, and there may be another number of sub-pixels that are arranged in an array. For example, each pixel cell may also include at least 9 sub-pixels arranged in an array, the at least 9 sub-pixels having three different colors, in order to spatially effect the mixed color display.
In
Similarly, as depicted in the pixel cell shown in setting B adjacent to the pixel cell shown in setting A, it can be seen that all of the first sub-pixels are displayed in a non-zero grayscale, and all of the second sub-pixels are displayed in a zero grayscale. Since luminance of the sub-pixels displayed in the zero grayscale is very low (about 0.3 nit), in this case, it is difficult for the human eye to recognize the polarity of the sub-pixels displayed in the zero grayscale, and therefore, the pixel cell shown in setting B has a single polarity, that is, a negative polarity.
It will be appreciated that in other embodiments, the polarities of the pixel cell shown in setting A and the polarity of the pixel cell shown in setting B may also be interchanged.
In
As shown in
In this case, by controlling a shutter time of the camera, it is possible to acquire grayscale of multiple frames at one time. For example, a refresh frequency of the liquid crystal display panel is 60 Hz, that is, 60 frames per second, and the shutter time is set to 1 second, so that when a photosensitive chip of the camera continuously senses light (this process is similar to integration), a luminance of the 60 frames may be obtained.
The grayscale of the pixel cell shown in A and the grayscale of the pixel cell shown in B may be simultaneously obtained from some of the frames to obtain the luminance corresponding to the grayscale. The grayscale of the pixel cell shown in C may be obtained from other frames, and the grayscale is correspondingly displayed as a black picture.
A curve of a relation between grayscales and gamma voltages is shown in
In
For example, for the pixel cell in the first row and the first column in each large block, the target grayscale is 128 and the grayscale compensation is +4, and a compensated grayscale is Z=X+Y=128+4=132. For the pixel cell in the first row and the second column in each large block, the target grayscale is 128, and the grayscale compensation is −1, and the compensated grayscale is Z=X+Y=128−1=127. Other pixel cells may be analogous, and will not be repeated one by one.
Herein, the target grayscale may be any value in the 0-255 grayscale, which may optimize flicker corresponding to the target grayscale.
The numerical values shown in
In
Luminance differences due to positive and negative polarities between adjacent pixel cells and adjusted grayscale differences form a number of demarcations at junctions between two pixel cells crossed by arrows as shown in
It will be appreciated that the grayscale of each pixel cell may be derived from the corresponding frame grayscale data.
It should be noted that the above-mentioned demarcation may be used to determine whether there is distortion in the camera photographing. As shown in
The grayscale difference between the grayscale compensation (−2) of the pixel cell shown in the first column in the second row and the grayscale compensation (+0) of the pixel cell shown in the second column in the second row, and the grayscale difference between the grayscale compensation (−0) of the pixel cell shown in the third column in the second row and the grayscale compensation (+2) of the pixel cell shown in the fourth column in the second row may be considered to be equal.
The grayscale difference between the grayscale compensation (−1) of the pixel cell shown in the first row in the second column and the grayscale compensation (+0) of the pixel cell shown in the second row in the second column, and the grayscale difference between the grayscale compensation (+1) of the pixel cell shown in the third row in the third column and the grayscale compensation (−0) of the pixel cell shown in the second row in the third column may be considered to be equal.
The grayscale difference between the grayscale compensation (+3) of the pixel cell shown in the first row in the third column and the grayscale compensation (−0) of the pixel cell shown in the second row in the third column, and the grayscale difference between the grayscale compensation (−3) of the pixel cell shown in the third row in the second column and the grayscale compensation (+0) of the pixel cell shown in the second row in the second column may be considered to be equal.
Edge gradient values of the two pixel cells whose grayscale differences are equal are theoretically equal, in this case, the camera takes a picture without distortion. Conversely, distortion occurs.
When at least one of the above grayscale differences exceeds a threshold value, for example, 1-2 grayscale, it indicates that there is distortion in the camera photographing.
The grayscale difference refers to the grayscale compensation of the “+” pixel cell minus the grayscale compensation of the “−” pixel cell. For example, the grayscale difference between the grayscale compensation (−2) of the pixel cell shown in the first column in the second row and the grayscale compensation (+0) of the pixel cell shown in the second column in the second row is (+0)−(−2)=2; the grayscale difference between the grayscale compensation (−0) of the pixel cell shown in the third column in the second row and the grayscale compensation (+2) of the pixel cell shown in the fourth column in the second row is (+2)−(−0)=2
As shown in
The edge gradient value may be a grayscale difference value or a grayscale difference.
For convenience of calculation and description, the curve of the relation in
The correction value for the common voltage is then determined to be one-half of the gamma voltage difference. Then, the correction value is added to the initial common voltage to obtain a target common voltage. In the positive half-cycles, the target common voltage and gamma voltages during positive half-cycles are used to control the twisting of the liquid crystal, while in the negative half-cycles, the target common voltage and gamma voltages during negative half-cycles are used to control the twisting of the liquid crystal, thereby reducing the luminance difference between the positive and negative half-cycles and thereby reducing the flicker value.
In one embodiment, the present embodiment provides a liquid crystal display panel that performs the compensation method in the at least one embodiment described above.
It will be appreciated that since the liquid crystal display panel according to the present embodiment performs the compensation method in at least one of the above-described embodiments, it is likewise possible to acquire a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data in the first place, with every two adjacent pixel cells of a plurality of pixel cells each having a single opposite polarity in one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data, and the plurality of pixel cells displaying a black picture in another one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data. A minimum grayscale difference between every adjacent pixel cells is determined based on one of the odd-numbered frame grayscale data or the even-numbered frame grayscale data. Then, a gamma voltage difference corresponding to the grayscale difference is determined according to a curve of a relation between grayscales and gamma voltages, followed by obtaining a correction value for a common voltage based on the gamma voltage difference. A flicker phenomenon can be improved by adjusting the common voltage only once through the correction value without requiring multiple iterations with low efficiency.
Also, the improvement in flicker can also be accomplished by dynamic pictures such as a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data, which extends types of flicker pattern required to adjust the flicker, as compared to the case where flicker is generally adjusted using a fixed flicker pattern.
Also, a plurality of consecutive and alternating odd-numbered frame grayscale data and even-numbered frame grayscale data can be acquired by one shot of a camera. A corresponding grayscale difference that can be identified based on the odd-numbered frame grayscale data and even-numbered frame grayscale data is used as a basis for determining the magnitude of a flicker value, which reduces the frequency of usage of an optical instrument compared with the conventional way in which the flicker value is measured by the corresponding optical instrument, thereby improving the efficiency of flicker adjustment.
In the above-mentioned embodiments, the description of each embodiment has its own emphasis, and parts not described in detail in a certain embodiment may be referred to the related description of other embodiments.
The liquid crystal display panel and the compensation method thereof provided in the embodiments of the present disclosure have been described in detail. The principles and embodiments of the present disclosure have been described by using specific examples. The description of the above embodiments is merely intended to help understand the technical solution and the core idea of the present disclosure. It will be appreciated by those of ordinary skill in the art that modifications may still be made to the technical solutions described in the foregoing embodiments, or equivalents may be made to some of the technical features therein. These modifications or substitutions do not depart the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure.
Number | Date | Country | Kind |
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202311301854.9 | Oct 2023 | CN | national |