Liquid crystal display device and backlight driving method thereof

Abstract

The application provides a liquid crystal display device and a backlight driving method thereof. The backlight module of the liquid crystal display device comprises a light emitting unit, a calculation unit, a comparison unit and a control unit. The calculation unit is used for calculating a first preset backlight brightness value of a corresponding backlight partition according to a partition average brightness value and a partition maximum brightness value of a display partition in a current frame display picture. The comparison unit is used for comparing the size of a second preset backlight brightness value of the backlight partition in a previous frame display picture and the first preset backlight brightness value and outputting a comparison result. The control unit is used for outputting a first brightness driving value of the backlight partition in the current frame display picture based on the comparison result. The light emitting unit emits light in the backlight partition based on the first brightness driving value, improves the backlight brightness of the backlight partition in a dark state display picture, and thus improves the detail display capability of the liquid crystal display device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a liquid crystal display device and a backlight driving method thereof. BACKGROUND

[0002] A liquid crystal display (LCD) with a mini light-emitting diode (Mini-LED) backlight dynamically adjusts the backlight brightness of a backlight module through a local dimming (LD) algorithm to achieve super-high contrast of a display picture. The LD algorithm counts the brightness information of a display picture corresponding to each backlight partition in the backlight module, and then selects a suitable backlight brightness according to the brightness information. The higher the brightness of a certain area of the display picture, the higher the brightness of the corresponding backlight partition. When a certain area of the display picture is a black picture, the corresponding backlight partition does not emit light. If the display picture to be displayed is a dark-state picture with small and scattered bright areas, for example, a starry sky picture, the average brightness of the display picture and the average brightness of the corresponding backlight partition are both very low, so that a backlight brightness value very close to zero is obtained through the LD algorithm. Once the backlight precision is not high, the backlight module will finally perform backlight output in a state with a backlight brightness value of zero, thereby causing loss of display details of the display picture, and resulting in insufficient detail display capability of the liquid crystal display device. SUMMARY

[0003] The present application provides a liquid crystal display device and a backlight driving method thereof to solve the problem of insufficient detail display capability of the liquid crystal display device when displaying a dark-state picture.

[0004] In a first aspect, the present application provides a liquid crystal display device, comprising:

[0005] a display panel, the display panel comprising a plurality of display partitions, wherein each display partition has a partition maximum brightness value and a partition average brightness value under each frame display picture;

[0006] a backlight module, the backlight module comprising:

[0007] a light-emitting unit, the light-emitting unit comprising a plurality of backlight partitions corresponding to the display partitions, wherein each backlight partition has a preset backlight brightness value under each frame display picture;

[0008] a calculation unit, the calculation unit being configured to calculate a first preset backlight brightness value according to the partition maximum brightness value, a first preset weight value corresponding to the partition maximum brightness value, the partition average brightness value, and a second preset weight value corresponding to the partition average brightness value, the first preset backlight brightness value being a preset backlight brightness value under a current frame display picture.

[0009] a comparison unit configured to compare a size of a second preset backlight brightness value of the backlight partition with the first preset backlight brightness value, and output a comparison result, the second preset backlight brightness value being a preset backlight brightness value under a previous frame of display picture;

[0010] a control unit configured to output a first brightness driving value of the backlight partition in a current frame of display picture based on the comparison result, so that the light emitting unit emits light in the backlight partition based on the first brightness driving value;

[0011] The control unit is configured to output the first brightness driving value based on the maximum brightness value of the partition, a first driving weight value corresponding to the maximum brightness value of the partition, the average brightness value of the partition, and a second driving weight value corresponding to the average brightness value of the partition, wherein the first driving weight value is determined according to the first preset weight value and a third driving weight value corresponding to the maximum brightness value of the partition of the backlight partition in the previous frame of display picture, and the second driving weight value is determined according to the second preset weight value and a fourth driving weight value corresponding to the average brightness value of the partition of the backlight partition in the previous frame of display picture.

[0012] The control unit is configured to, in a case where the comparison result is that the first preset backlight brightness value is different from the second preset backlight brightness value, determine whether an average gray scale value of the current frame of display picture satisfies being less than a first preset threshold value and whether a backlight gray scale maximum value of the backlight partition in the current frame of display picture satisfies being less than a second preset threshold value, and if not, determine the first preset weight value as the first driving weight value, and determine the second preset weight value as the second driving weight value.

[0013] In the liquid crystal display device provided in the present application, the control unit is configured to calculate the first brightness driving value according to a first preset relationship, the first preset relationship being: L(x) = k1 × L_max(x) + k2 × L_av(x), wherein L(x) is the first brightness driving value, L_max(x) is the maximum brightness value of the partition, L_av(x) is the average brightness value of the partition, k1 is the first driving weight value, and k2 is the second driving weight value.

[0014] In the liquid crystal display device provided in the present application, the control unit is further configured to calculate a size of one of the first driving weight value and the second driving weight value based on the other one of the first driving weight value and the second driving weight value and a second preset relationship, the second preset relationship being: k1 + k2 = 1.

[0015] In the liquid crystal display device provided in the present application, the control unit is configured to determine the third driving weight value as the first driving weight value of the backlight partition in the current frame display picture and determine the fourth driving weight value as the second driving weight value of the backlight partition in the current frame display picture when the comparison result is that the first preset backlight brightness value is the same as the second preset backlight brightness value.

[0016] In the liquid crystal display device provided in the present application, the calculation unit is further configured to calculate the average gray scale value of the current frame display picture and the maximum backlight gray scale value of all the backlight partitions in the current frame display picture when the comparison result is that the first preset backlight brightness value is different from the second preset backlight brightness value.

[0017] In the liquid crystal display device provided in the present application, if the condition is met, the control unit is further configured to determine the first driving weight value of the backlight partition in the current frame display picture according to the first preset weight value and the weight adjustment value, and determine the second driving weight value of the backlight partition in the current frame display picture according to the second preset weight value and the weight adjustment value.

[0018] In the liquid crystal display device provided in the present application, the control unit is configured to determine the first driving weight value of the backlight partition in the current frame display picture according to the first preset weight value, the weight adjustment value and a third preset relationship, the third preset relationship being ky1+k0=k1, wherein ky1 is the first preset weight value, k0 is the weight adjustment value, and k1 is the first driving weight value of the backlight partition in the current frame display picture.

[0019] In a second aspect, the present application further provides a backlight driving method of a liquid crystal display device, the liquid crystal display device comprising a display panel and a backlight module, the display panel comprising a plurality of display partitions, each of the display partitions having a partition maximum brightness value and a partition average brightness value in each frame display picture, the backlight module comprising a plurality of backlight partitions corresponding to the display partitions, each of the backlight partitions having a preset backlight brightness value in each frame display picture, the backlight driving method comprising:

[0020] calculating the partition average brightness value of the display partition in the current frame display picture;

[0021] calculating the partition maximum brightness value of the display partition in the current frame display picture;

[0022] calculating the first preset backlight brightness value based on the first preset weight value corresponding to the maximum brightness value of the partition, the second preset weight value corresponding to the average brightness value of the partition, the average brightness value of the partition and the maximum brightness value of the partition, the first preset backlight brightness value being a preset backlight brightness value under a current frame display picture;

[0023] comparing the backlight partition in the second preset backlight brightness value of the last frame display picture with the first preset backlight brightness value, and outputting a comparison result, the second preset backlight brightness value being a preset backlight brightness value under a last frame display picture;

[0024] if the comparison result is that the second preset backlight brightness value is the same as the first preset backlight brightness value, determining a third driving weight value corresponding to the maximum brightness value of the partition in the last frame display picture of the backlight partition as a first driving weight value, and determining a fourth driving weight value corresponding to the average brightness value of the partition in the last frame display picture of the backlight partition as a second driving weight value;

[0025] if the comparison result is that the second preset backlight brightness value is different from the first preset backlight brightness value, judging whether the average gray scale value of the current frame display picture satisfies less than a first preset threshold and whether the maximum backlight gray scale value of all the backlight partitions in the current frame display picture satisfies less than a second preset threshold;

[0026] if not, determining the first preset weight value as the first driving weight value, and determining the second preset weight value as the second driving weight value;

[0027] outputting a first brightness driving value according to the first driving weight value, the second driving weight value, the average brightness value of the partition and the maximum brightness value of the partition;

[0028] controlling the backlight partition to emit light based on the first brightness driving value.

[0029] In the backlight driving method provided in the present application, the step of outputting the first brightness driving value according to the first driving weight value, the second driving weight value, the average brightness value of the partition and the maximum brightness value of the partition comprises:

[0030] The first luminance driving value is output according to a first preset relationship, the first driving weight value, the second driving weight value, the partition average luminance value and the partition maximum luminance value, the first preset relationship being: L(x) = k1*L_max(x) + k2*L_av(x), wherein L(x) is the first luminance driving value, L_max(x) is the partition maximum luminance value, L_av(x) is the partition average luminance value, k1 is the first driving weight value, and k2 is the second driving weight value.

[0031] In the backlight driving method provided in the application, the size of the other one of the first driving weight value and the second driving weight value is calculated based on one of the first driving weight value and the second driving weight value and a second preset relationship, the second preset relationship being: k1+k2=1.

[0032] In the backlight driving method provided in the application, the size of the other one of the first driving weight value and the second driving weight value is calculated based on one of the first driving weight value and the second driving weight value and a second preset relationship, the second preset relationship being: k1+k2=1.

[0033] If the condition is met, a weight adjustment value is obtained.

[0034] The first driving weight value is determined according to the first preset weight value and the weight adjustment value.

[0035] The second driving weight value is determined according to the second preset weight value and the weight adjustment value.

[0036] In the backlight driving method provided in the application, the step of determining the first driving weight value according to the first preset weight value and the weight adjustment value comprises:

[0037] The first driving weight value is determined according to the first preset weight value, the weight adjustment value and a third preset relationship, the third preset relationship being: ky1+k0=k1, wherein ky1 is the first preset weight value, k0 is the weight adjustment value, and k1 is the first driving weight value.

[0038] The liquid crystal display device provided in the application compares the size of the second preset backlight luminance value of the backlight partition in the previous frame display picture and the first preset backlight luminance value of the current frame display picture through the comparison unit, so that the control unit outputs the luminance driving value corresponding to the comparison result, and the light emitting unit emits light in the corresponding backlight partition based on the luminance driving value, thereby improving the backlight luminance of the backlight partition in the dark state display picture, and further improving the detail display capability of the liquid crystal display device. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A block diagram of the liquid crystal display device provided in the embodiments of the application is shown in the figure.

[0040] Figure 2 A first block diagram of the backlight module provided by the embodiment of the present application is provided as follows;

[0041] Figure 3 A second block diagram of the backlight module provided by the embodiment of the present application is provided as follows;

[0042] Figure 4 A first flow chart of the driving method of the liquid crystal display device provided by the embodiment of the present application is provided as follows;

[0043] Figure 5 A specific flow chart of S10 in the embodiment of the present application is provided as follows; Figure 4

[0044] Figure 6 A second flow chart of the driving method of the liquid crystal display device provided by the embodiment of the present application is provided as follows. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. The described embodiments are only used to explain and describe the ideas of the present application, and should not be regarded as limiting the protection scope of the present application.

[0046] As shown in FIG. 1, the liquid crystal display device 100 provided by the embodiment of the present application includes a display panel 10 and a backlight module 20. The display panel 10 includes a display area and a non-display area other than the display area, the display area includes a plurality of display sub-areas AA1, and the display sub-area AA1 is provided with a plurality of pixels. Figure 1

[0047] As shown in FIG. 2, the backlight module 20 specifically includes a light emitting unit 201, a calculation unit 202, a comparison unit 203 and a control unit 204. Figure 2

[0048] The light emitting unit 201 includes a plurality of backlight sub-areas BA1 corresponding to the display sub-areas AA1, and each backlight sub-area BA1 is provided with a plurality of Mini-LEDs. The light emitting unit 201 is driven by a local dimming (LD) mode. The plurality of backlight sub-areas BA1 and the plurality of display sub-areas AA1 have a one-to-one correspondence, that is, each display sub-area AA1 has a corresponding backlight sub-area BA1 to provide a backlight source for picture display. The LD algorithm is used to divide the entire light emitting unit 201 into a plurality of independently drivable backlight sub-areas BA1. According to the gray scale required to be displayed by different regions of the display picture, the driving current of the LED of the backlight sub-area corresponding to the corresponding part is automatically adjusted, so as to realize the independent adjustment of the brightness of each backlight sub-area BA1 in the light emitting unit 201, thereby improving the contrast of the display picture.

[0049] ​​​The computing unit 202 is configured to calculate a first preset backlight luminance value of the backlight partition BA1 corresponding to the display partition AA1 according to the partition average luminance value and the partition maximum luminance value of the display partition AA1 in the current frame display picture. The first preset backlight luminance value of the backlight partition BA1 in the current frame display picture is related to the display luminance of the display partition AA1 corresponding to the backlight partition BA1, and the preset backlight luminance value of the backlight partition BA1 depends on the display luminance value of the frame display picture corresponding to the display partition AA1 corresponding to the backlight partition BA1.

[0050] The computing unit 202 obtains the luminance values of all the pixels in the display partition AA1 and determines the maximum luminance value of the pixels in the display partition AA1, and determines the maximum luminance value of the pixels in the display partition AA1 as the partition maximum luminance value of the display partition AA1.

[0051] The computing unit 202 accumulates the luminance values of all the pixels in the display partition AA1 to obtain the luminance value sum of the display partition AA1, and then obtains the partition average luminance value of the display partition AA1 according to the luminance value sum of the display partition AA1 and the number of pixels in the display partition AA1.

[0052] The computing unit 202 is further configured to calculate the first preset backlight luminance value based on the partition average luminance value of the display partition AA1 corresponding to the backlight partition BA1 in the current frame display picture, the partition maximum luminance value of the same display partition AA1, a first preset weight value and a second preset weight value, wherein the first preset weight value is a weight value corresponding to the partition maximum luminance value, and the second preset weight value is a weight value corresponding to the partition average luminance value. The first preset weight values corresponding to different backlight partitions BA1 in different frame display pictures are the same, and the second preset weight values corresponding to different backlight partitions BA1 in different frame display pictures are the same.

[0053] The first preset weight value is a weight value of the preset partition maximum luminance value stored in the computing unit 202. The second preset weight value is a weight value of the preset partition average luminance value stored in the computing unit 202.

[0054] When the luminance value of the backlight partition BA1 is calculated based on the LD algorithm, the partition average luminance value and the partition maximum luminance value of the display picture corresponding to the backlight partition BA1 are referred to, and the luminance value of the backlight partition BA1 can be adjusted by adjusting the weight values of the partition maximum luminance value and the partition average luminance value. Therefore, the preset backlight luminance value of the corresponding backlight partition BA1 can be calculated based on the first preset weight value, the partition maximum luminance value, the second preset weight value, and the partition average luminance value. In the LD algorithm, increasing the first preset weight value increases the luminance of all backlight partitions BA1, which may improve the details of the initial dark area of the display picture, but the halo of the initial bright area of the display picture becomes more serious. Therefore, the first preset weight value should not be too large and should be less than 1.

[0055] The comparison unit 203 is configured to compare the size of the second preset backlight luminance value and the first preset backlight luminance value of the backlight partition BA1 in the previous frame of the display picture, and output a comparison result. The comparison unit 203 compares the size of the preset backlight luminance values of the same backlight partition BA1 in the previous and subsequent frames of the display picture, and outputs a comparison result that the preset backlight luminance values of the same backlight partition BA1 in the previous and subsequent frames of the display picture are the same or different. The comparison unit 203 can also store the preset backlight luminance values of each backlight partition BA1 in different frames of the display picture, so as to compare the preset backlight luminance values of a specific backlight partition BA1 in the previous and subsequent frames of the display picture.

[0056] The control unit 204 is configured to output a first luminance driving value of the backlight partition BA1 in the current frame of the display picture based on the comparison result, so that the light emitting unit 201 emits light in the corresponding backlight partition based on the first luminance driving value, wherein the first luminance driving value is determined according to the second luminance driving value of the same backlight partition BA1 in the previous frame of the display picture and the first preset backlight luminance value of the current frame of the display picture.

[0057] If the size of the first preset backlight luminance value and the second preset backlight luminance value of the same backlight partition BA1 is the same, the luminance data corresponding to the backlight partition BA1 does not change in the previous and subsequent frames of the display picture, and there is no need to adjust the detail display capability of the backlight partition BA1 under the current frame of the display picture, that is, there is no need to enhance the weight values of the partition maximum luminance value and the partition average luminance value corresponding to the display partition BA1.

[0058] In the case of the comparison result, the control unit 204 acquires the first driving weight value of the backlight partition BA1 corresponding to the previous frame of the display picture and the second driving weight value of the backlight partition BA1 corresponding to the frame of the display picture, determines the first driving weight value of the backlight partition BA1 in the previous frame of the display picture as the first driving weight value in the current frame of the display picture, and determines the second driving weight value of the backlight partition BA1 in the previous frame of the display picture as the second driving weight value in the current frame of the display picture. That is, the first driving weight value of the backlight partition BA1 in the previous and subsequent frames of the display picture is the same, and the second driving weight value of the backlight partition BA1 in the previous and subsequent frames of the display picture is the same.

[0059] If the second preset backlight brightness value and the first preset backlight brightness value of the same backlight partition BA1 are different in size, the luminance data corresponding to the backlight partition BA1 changes in the previous and subsequent frames, and the detail display capability of the backlight partition BA1 under the current frame of the display picture needs to be optimized, that is, the weight value of the partition maximum brightness value and the weight value of the partition average brightness value corresponding to the display partition BA1 need to be adjusted.

[0060] The control unit 204 outputs the first luminance driving value based on the partition maximum brightness value, the first driving weight value corresponding to the partition maximum brightness value, the partition average brightness value, and the second driving weight value corresponding to the partition average brightness value. The first driving weight value of the backlight partition in the current frame of the display picture is determined according to the first preset weight value and the first driving weight value corresponding to the second luminance driving value, wherein the first driving weight value is determined according to the first preset weight value and the third driving weight value corresponding to the partition maximum brightness value of the same backlight partition in the previous frame of the display picture, and the second driving weight value is determined according to the second preset weight value and the fourth driving weight value corresponding to the partition average brightness value of the same backlight partition in the previous frame of the display picture. The control unit 204 can also store the driving weight value corresponding to the partition maximum brightness value and the driving weight value corresponding to the partition average brightness value of each backlight partition BA1 in each frame of the display picture, so as to compare the driving weight values of a specific backlight partition BA1 in the previous and subsequent frames of the display picture.

[0061] The control unit 204 is configured to calculate the first luminance driving value according to a first preset relationship. The first preset relationship is:

[0062] L(x) = k1*L_max(x) + k2*L_av(x) (1);

[0063] In the above first preset relational expression (1), L(x) is the first luminance driving value, L_max(x) is the maximum luminance value of the partition, L_av(x) is the average luminance value of the partition, k1 is the first driving weight value of the current frame display image, and k2 is the second driving weight value of the current frame display image. The value range of k1 is: 0 < k1 < 1, and the value range of k2 is: 0 < k2 < 1.

[0064] When the maximum luminance value of the partition and the average luminance value of the partition are determined, adjusting the magnitudes of the first driving weight value and / or the second driving weight value can adjust the magnitude of the luminance driving value, and further adjust the backlight luminance of the corresponding backlight partition BA1, so as to improve the backlight accuracy of the corresponding backlight partition BA1, ensure the normal display of the details of the display image of the corresponding backlight partition BA1, and thus improve the detail display ability of the liquid crystal display device.

[0065] The control unit 204 is further configured to calculate the magnitude of the other of the first driving weight value and the second driving weight value based on one of the first driving weight value and the second driving weight value and a second preset relational expression. The second preset relational expression is:

[0066] k1 + k2 = 1 (2);

[0067] In the above relational expression (2), k1 is the first driving weight value, and k2 is the second driving weight value.

[0068] The control unit 204 outputs a corresponding luminance driving value based on the comparison result that the preset backlight luminance values of the same backlight partition BA1 in the front and back two frame display images are the same, so that the light emitting unit 201 emits light in the backlight partition based on the luminance driving value. The control unit 204 outputs a corresponding luminance driving value based on the comparison result that the preset backlight luminance values of the same backlight partition BA1 in the front and back two frame display images are different, so that the light emitting unit 201 emits light in the backlight partition based on the luminance driving value.

[0069] As Figure 3 shown, in the liquid crystal display device 100 provided in this embodiment, the backlight module 20 may further include a storage unit 205. The storage unit 205 is configured to store in real time the preset backlight luminance values of each backlight partition BA1 in different frame display images, so as to provide in real time the preset backlight luminance value of a certain backlight partition BA1 in a certain frame display image to the comparison unit 203. The storage unit 205 may also be configured to store in real time the driving weight values corresponding to the maximum luminance value of the partition and the driving weight values corresponding to the average luminance value of the partition in each frame display image of each partition BA1, so as to provide in real time the corresponding driving weight value of a certain backlight partition BA1 in a certain frame display image to the control unit 204.

[0070] The liquid crystal display device 100 compares the preset backlight brightness value of the backlight partition BA1 in the previous frame display picture and the preset backlight brightness value of the current frame display picture by the comparison unit 203, so that the control unit 204 outputs the brightness driving value corresponding to the comparison result, so that the light emitting unit 201 emits light in the corresponding backlight partition based on the brightness driving value, improves the backlight brightness of the backlight partition BA1 in the dark state display picture, and further improves the detail display capability of the liquid crystal display device.

[0071] In the liquid crystal display device provided in the present application, in the case of the comparison result that the preset backlight brightness values of the same backlight partition BA1 in the previous frame display picture and the current frame display picture are different, and in the case that the first preset backlight brightness value and the second preset backlight brightness value are different, the calculation unit 202 is further used to calculate the average gray scale value of the display panel 10 in the current frame display picture and the maximum backlight gray scale value of all backlight partitions BA1 in the current frame display picture.

[0072] The calculation unit 202 obtains the gray scale values of all pixels of all display partitions AA1 in the current frame display picture, accumulates the brightness values of all pixels to obtain the gray scale value sum of the display panel 10, and then obtains the average gray scale value of the display panel 10 in the current frame display picture according to the gray scale value sum of the display panel 10 and the total number of pixels of the display panel 10.

[0073] The calculation unit 202 obtains the gray scale values of all Mini-LEDs of all backlight partitions BA1 in the current frame display picture, and determines the maximum gray scale value of the Mini-LEDs in all backlight partitions BA1.

[0074] The control unit 204 is further used to judge whether the average gray scale value of the display panel 10 in the current frame display picture satisfies less than the first preset threshold value and whether the maximum backlight gray scale value of all backlight partitions BA1 in the current frame display picture satisfies less than the second preset threshold value.

[0075] If the average gray scale value of the display panel 10 in the current frame display picture is greater than or equal to the first preset threshold value, the average brightness of the current frame display picture is high, and all the Mini-LEDs in the light emitting unit 201 are turned on or only a few are turned off in the current frame display picture.

[0076] Therefore, the luminance of the backlight partition BA1 does not need to be adjusted, the detail display capability of the backlight partition BA1 under the current frame display picture does not need to be optimized, that is, the weight value of the partition maximum luminance value and the weight value of the partition average luminance value corresponding to the backlight partition BA1 do not need to be adjusted. Under this determination result, the control unit 204 determines the first preset weight value as the first driving weight value and determines the second preset weight value as the second driving weight value, so the size of the first preset backlight luminance value of the backlight partition BA1 is the same as the size of the first light-emitting driving value of the backlight partition BA1, and the light-emitting unit 201 emits light in the corresponding backlight partition BA1 based on the first preset backlight luminance value under the current frame display picture.

[0077] If the average gray scale value of the display panel 10 under the current frame display picture is less than the first preset threshold value, but the backlight gray scale maximum value of all the backlight partitions BA1 under the current frame display picture is greater than or equal to the second preset threshold value, the average luminance of the current frame display picture is low and the peak luminance of the current frame display picture is high, and in this case, there is a backlight partition BA1 with high backlight luminance, the backlight partition BA1 generates light diffusion phenomenon based on the high backlight luminance, and the light diffusion phenomenon improves the detail display capability of the dark area around the backlight partition BA1 with high backlight luminance.

[0078] Therefore, the luminance of the backlight partition BA1 does not need to be adjusted, the detail display capability of the backlight partition BA1 under the current frame display picture does not need to be optimized, that is, the weight value of the partition maximum luminance value and the weight value of the partition average luminance value corresponding to the backlight partition BA1 do not need to be adjusted. Under this determination result, the control unit 204 determines the first preset weight value as the first driving weight value and determines the second preset weight value as the second driving weight value, so the size of the first preset backlight luminance value of the backlight partition BA1 is the same as the size of the first light-emitting driving value of the backlight partition BA1, and the light-emitting unit 201 emits light in the corresponding backlight partition BA1 based on the first preset backlight luminance value under the current frame display picture.

[0079] If the average gray scale value of the display panel 10 under the current frame display picture is less than the first preset threshold value, and the backlight gray scale maximum value of all the backlight partitions BA1 under the current frame display picture is less than the second preset threshold value, the overall luminance of all the backlight partitions BA1 is low or all the Mini-LEDs of all the backlight partitions BA1 are in the off state, in order to ensure the detail display of the display partition AA1 corresponding to the backlight partition BA1, the detail display capability of the backlight partition BA1 needs to be improved in this case.

[0080] According to the judgment result, the control unit 204 is further configured to determine a first driving weight value of the backlight partition BA1 in the current frame display picture according to the first preset weight value and the weight adjustment value, and determine a second driving weight value of the same backlight partition in the current frame display picture according to the second preset weight value and the weight adjustment value.

[0081] The specific value of the weight adjustment value is determined through experiment debugging, and the control unit 204 determines the first driving weight value according to the first preset weight value, the weight adjustment value determined through experiment debugging, and a third preset relationship. The third preset relationship is:

[0082] ky1+k0=k1 (3);

[0083] In the third preset relationship (3) above, ky1 is the first preset weight value, k0 is the weight adjustment value, and k1 is the first driving weight value. The specific value range of the weight adjustment value k0 is 0 < k0 < 1-ky1. In order to improve the detail display capability of the dark state display picture corresponding to the backlight partition BA1, it is necessary to increase the weight value corresponding to the maximum brightness value of the partition, so the weight adjustment value should be greater than 0. At the same time, in order to avoid the expansion of the display picture halo corresponding to the backlight partition BA1 after excessive dimming, the first driving weight value k1 calculated from the first preset weight value ky1 and the weight adjustment value k0 should be less than 1, that is, the weight adjustment value should be less than the difference between 1 and the first preset weight value ky1 while being greater than 0.

[0084] Since the first driving weight value and the corresponding second driving weight value determined again still need to satisfy the second preset relationship (2) above, the corresponding second driving weight value can be calculated based on the first driving weight value determined again and the second preset relationship (2). Then, the brightness driving value of the corresponding backlight partition in the current frame display picture is calculated according to the first preset relationship (1), the first driving weight value determined again, the corresponding second driving weight value, the partition average brightness value, and the partition maximum brightness value of the backlight partition.

[0085] The liquid crystal display device 100 can also determine the size between the average gray scale value of the current frame display picture and the first preset threshold value, and the size between the maximum backlight gray scale value of all backlight partitions in the current frame display picture and the second preset threshold value through the control unit 204. While improving the display brightness of the backlight partition BA1 in the dark state display picture to improve the detail display capability of the liquid crystal display device, it can also avoid excessive dimming of the backlight partition BA1 to expand the corresponding display picture halo.

[0086] As Figure 4As shown, the embodiment of the present application also provides a backlight driving method of a liquid crystal display device. The liquid crystal display device of the embodiment comprises a display panel and a backlight module. The display panel comprises a plurality of display partitions. The backlight module comprises a plurality of backlight partitions corresponding to the display partitions. The backlight driving method of the embodiment comprises the following steps:

[0087] S10, calculating a first preset backlight brightness value of the backlight partition corresponding to the display partition according to a partition average brightness value and a partition maximum brightness value of the display partition in a current frame display picture. For example, Figure 5 As shown, step S10 can specifically comprise:

[0088] S101, calculating the partition average brightness value of the display partition in the current frame display picture. The brightness values of all the pixels in the display partition are added to obtain the brightness value sum of the display partition. Then, the brightness value sum of the display partition AA1 is divided by the number of pixels in the display partition to obtain the partition average brightness value of the display partition.

[0089] S102, calculating the partition maximum brightness value of the display partition in the current frame display picture. The brightness values of all the pixels in the display partition are obtained and the maximum brightness value of the pixels in the display partition is determined. The maximum brightness value of the pixels in the display partition is determined as the partition maximum brightness value.

[0090] S103, calculating the first preset backlight brightness value based on a first preset weight value corresponding to the partition maximum brightness value, a second preset weight value corresponding to the partition average brightness value, the partition average brightness value and the partition maximum brightness value.

[0091] S20, comparing the second preset backlight brightness value of the backlight partition in a previous frame display picture with the first preset backlight brightness value and outputting a comparison result. That is, whether the sizes of the preset backlight brightness values of the same backlight partition in the previous frame and the current frame are the same is compared.

[0092] The comparison result in step S20 has two kinds. The first comparison result is that the sizes of the second preset backlight brightness value and the first preset backlight brightness value are the same. The second comparison result is that the sizes of the second preset backlight brightness value and the first preset backlight brightness value are different.

[0093] S30, outputting a first brightness driving value of the backlight partition in the current frame display picture based on the comparison result.

[0094] The backlight driving method of the liquid crystal display device provided by the embodiment compares the preset backlight brightness of the backlight partition in the last frame of display picture with the preset backlight brightness of the backlight partition in the current frame of display picture, determines the first brightness driving value of the backlight partition in the current frame of display picture based on the comparison result, and thereby improves the display brightness of the backlight partition in the dark state display picture to improve the detail display capability of the liquid crystal display device.

[0095] In combination Figure 4 And Figure 6 As shown in the figure, step S30 can specifically include step S301 and step S302.

[0096] S301, determining the first driving weight value corresponding to the maximum brightness value of the partition and the second driving weight value corresponding to the average brightness value of the partition based on the comparison result.

[0097] Step S301 can further specifically include the following:

[0098] S3011, if the comparison result is that the second preset backlight brightness value is the same as the first preset backlight brightness value, determining the third driving weight value corresponding to the maximum brightness value of the partition in the last frame of display picture of the backlight partition as the first driving weight value, and determining the fourth driving weight value corresponding to the average brightness value of the partition in the last frame of display picture of the backlight partition as the second driving weight value.

[0099] S3012, if the comparison result is that the second preset backlight brightness value is different from the first preset backlight brightness value, judging whether the average gray scale value of the current frame of display picture satisfies less than the first preset threshold value and whether the maximum value of the backlight gray scale of all the backlight partitions in the current frame of display picture satisfies less than the second preset threshold value, and determining the first driving weight value and the second driving weight value according to the judgment result.

[0100] And step S3012 can further include:

[0101] S30121, if not, determining the first preset weight value as the first driving weight value, and determining the second preset weight value as the second driving weight value.

[0102] S30122, if yes, that is, if the average gray scale value of the current frame of display picture satisfies less than the first preset threshold value and the maximum value of the backlight gray scale of all the backlight partitions in the current frame of display picture satisfies less than the second preset threshold value, obtaining a weight adjustment value, determining the first driving weight value according to the first preset weight value and the weight adjustment value, and determining the second driving weight value according to the second preset weight value and the weight adjustment value.

[0103] In step S30122, the first driving weight value can be determined according to the first preset weight value, the weight adjustment value and a third preset relationship. The third preset relationship is:

[0104] ky1+k0=k1(3);

[0105] In the third preset relationship (3), ky1 is a first preset weight value, k0 is a weight adjustment value, and k1 is a first driving weight value. The weight adjustment value k0 has a specific value range of 0 < k0 < 1-ky1.

[0106] S302, output a first luminance driving value according to the first driving weight value, the second driving weight value, the partition average luminance value, and the partition maximum luminance value.

[0107] In step S302, the first luminance driving value can be output according to the first preset relationship, the first driving weight value, the second driving weight value, the partition average luminance value, and the partition maximum luminance value, wherein the first preset relationship is:

[0108] L(x) = k1*L_max(x) + k2*L_av(x)(1);

[0109] In the first preset relationship (1), L(x) is the first luminance driving value, L_max(x) is the partition maximum luminance value, L_av(x) is the partition average luminance value, k1 is the first driving weight value, and k2 is the second driving weight value. The value range of k1 is 0 < k1 < 1, and the value range of k2 is 0 < k2 < 1.

[0110] In step S302, the size of one of the first driving weight value and the second driving weight value can also be calculated based on the other one of the first driving weight value and the second driving weight value and the second preset relationship. The second preset relationship is:

[0111] k1+ k2=1(2);

[0112] In the relationship (2), k1 is the first driving weight value, and k2 is the second driving weight value.

[0113] S40, control the backlight partition to emit light based on the first luminance driving value.

[0114] The backlight driving method of the liquid crystal display device provided in the embodiment can determine the first luminance driving value of the backlight partition in the current frame display picture based on the size between the average gray scale value of the current frame display picture and the first preset threshold value and the size between the maximum value of the backlight gray scale of all the backlight partitions in the current frame display picture and the second preset threshold value, thereby improving the display luminance of the backlight partition in the dark state display picture to improve the detail display capability of the liquid crystal display device, and avoiding the problem of excessive dimming of the backlight partition to cause the corresponding display picture to have a large halo.

[0115] Of course, the present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications to the present application according to the present application, without departing from the spirit and essential characteristics of the present application, and these corresponding changes and modifications should all belong to the protection scope of the claims appended to the present application.

Claims

1. A liquid crystal display device, characterized by comprising: The display panel comprises a plurality of display partitions, wherein each of the display partitions has a maximum partition luminance value and an average partition luminance value under each frame display picture. The backlight module comprises: A light emitting unit comprising a plurality of backlight partitions corresponding to the display partitions, wherein each of the backlight partitions has a preset backlight luminance value under each frame display picture. A calculation unit configured to calculate a first preset backlight luminance value according to the maximum partition luminance value, a first preset weight value corresponding to the maximum partition luminance value, the average partition luminance value, and a second preset weight value corresponding to the average partition luminance value, the first preset backlight luminance value being the preset backlight luminance value under a current frame display picture. A comparison unit configured to compare the size of a second preset backlight luminance value of the backlight partition and the first preset backlight luminance value, the second preset backlight luminance value being the preset backlight luminance value under a previous frame display picture, and output a comparison result. A control unit configured to output a first luminance driving value of the backlight partition in the current frame display picture based on the comparison result, so that the light emitting unit emits light in the backlight partition based on the first luminance driving value. The control unit is configured to output the first luminance driving value based on the maximum partition luminance value, a first driving weight value corresponding to the maximum partition luminance value, the average partition luminance value, and a second driving weight value corresponding to the average partition luminance value, wherein the first driving weight value is determined according to the first preset weight value and a third driving weight value of the backlight partition corresponding to the maximum partition luminance value in the previous frame display picture, and the second driving weight value is determined according to the second preset weight value and a fourth driving weight value of the backlight partition corresponding to the average partition luminance value in the previous frame display picture. The control unit is configured to determine whether the average gray scale value of the current frame display picture satisfies a condition of being less than a first preset threshold value and whether the backlight gray scale maximum value of all the backlight partitions in the current frame display picture satisfies a condition of being less than a second preset threshold value if the comparison result is that the first preset backlight luminance value is different from the second preset backlight luminance value, and to determine the first preset weight value as the first driving weight value and the second preset weight value as the second driving weight value if the conditions are not satisfied. The control unit is configured to calculate the first luminance driving value according to a first preset relationship, which is L(x) = k1×L_max(x) + k2×L_av(x), wherein L(x) is the first luminance driving value, L_max(x) is the maximum partition luminance value, L_av(x) is the average partition luminance value, k1 is the first driving weight value, and k2 is the second driving weight value.

2. The liquid crystal display device according to claim 1, wherein ​ 3. The liquid crystal display device according to claim 2, wherein The control unit is further configured to calculate a size of one of the first driving weight value and the second driving weight value based on the other one of the first driving weight value and the second driving weight value and a second preset relationship, the second preset relationship being k1+k2=1.

4. The liquid crystal display device according to claim 1, wherein The control unit is configured to, in a case where the comparison result is that the first preset backlight brightness value is the same as the second preset backlight brightness value, determine the third driving weight value as the first driving weight value of the backlight partition in the current frame display picture and determine the fourth driving weight value as the second driving weight value of the backlight partition in the current frame display picture.

5. The liquid crystal display device according to claim 1, wherein The calculation unit is further configured to, in a case where the comparison result is that the first preset backlight brightness value is different from the second preset backlight brightness value, calculate the average gray scale value of the current frame display picture and the maximum backlight gray scale value of all the backlight partitions in the current frame display picture.

6. The liquid crystal display device according to claim 1, wherein If the condition is met, the control unit is further configured to determine the first driving weight value of the backlight partition in the current frame display picture according to the first preset weight value and a weight adjustment value and determine the second driving weight value of the backlight partition in the current frame display picture according to the second preset weight value and the weight adjustment value.

7. The liquid crystal display device according to claim 6, wherein The control unit is configured to determine the first driving weight value of the backlight partition in the current frame display picture according to the first preset weight value, the weight adjustment value and a third preset relationship, the third preset relationship being ky1+k0=k1, where ky1 is the first preset weight value, k0 is the weight adjustment value and k1 is the first driving weight value of the backlight partition in the current frame display picture. 8.A backlight driving method of a liquid crystal display device, the liquid crystal display device comprising a display panel and a backlight module, the display panel comprising a plurality of display subzones, each of the display subzones having a subzone maximum luminance value and a subzone average luminance value under each frame of display picture, the backlight module comprising a plurality of backlight subzones corresponding to the display subzones, each of the backlight subzones having a preset backlight luminance value under each frame of display picture, characterized in that, The backlight driving method comprises: calculating a partition average brightness value of the display partition in the current frame display picture; calculating a partition maximum brightness value of the display partition in the current frame display picture; calculating the first preset backlight brightness value based on a first preset weight value corresponding to the partition maximum brightness value, a second preset weight value corresponding to the partition average brightness value, the partition average brightness value and the partition maximum brightness value, the first preset backlight brightness value being a preset backlight brightness value under the current frame display picture; comparing a second preset backlight brightness value of the backlight partition in the previous frame display picture with the first preset backlight brightness value and outputting a comparison result, the second preset backlight brightness value being a preset backlight brightness value under the previous frame display picture; if the comparison result is that the second preset backlight brightness value is the same as the first preset backlight brightness value, determining a third driving weight value corresponding to the partition maximum brightness value of the backlight partition in the previous frame display picture as a first driving weight value and determining a fourth driving weight value corresponding to the partition average brightness value of the backlight partition in the previous frame display picture as a second driving weight value; If the comparison result is that the second preset backlight brightness value is different from the first preset backlight brightness value, it is determined whether an average gray scale value of a current frame display picture satisfies a first preset threshold value and whether a maximum backlight gray scale value of all the backlight partitions in the current frame display picture satisfies a second preset threshold value; If not, the first preset weight value is determined as the first driving weight value, and the second preset weight value is determined as the second driving weight value; A first brightness driving value is output according to the first driving weight value, the second driving weight value, the partition average brightness value and the partition maximum brightness value; The backlight partitions are controlled to emit light based on the first brightness driving value.

9. The backlight driving method of claim 8, wherein, The step of outputting the first brightness driving value according to the first driving weight value, the second driving weight value, the partition average brightness value and the partition maximum brightness value comprises: The first brightness driving value is output according to a first preset relationship, the first driving weight value, the second driving weight value, the partition average brightness value and the partition maximum brightness value, the first preset relationship being L(x) = k1×L_max(x) + k2×L_av(x), wherein L(x) is the first brightness driving value, L_max(x) is the partition maximum brightness value, L_av(x) is the partition average brightness value, k1 is the first driving weight value, and k2 is the second driving weight value.

10. The backlight driving method of claim 9, wherein, Further comprising: The size of one of the first driving weight value and the second driving weight value is calculated based on the other one of the first driving weight value and the second driving weight value and a second preset relationship, the second preset relationship being k1 + k2 = 1.

11. The backlight driving method of claim 8, wherein, Further comprising: If yes, a weight adjustment value is obtained; The first driving weight value is determined according to the first preset weight value and the weight adjustment value; The second driving weight value is determined according to the second preset weight value and the weight adjustment value.

12. The backlight driving method of claim 11, wherein, The step of determining the first driving weight value according to the first preset weight value and the weight adjustment value comprises: The first driving weight value is determined according to the first preset weight value, the weight adjustment value and a third preset relationship, the third preset relationship being ky1 + k0 = k1, wherein ky1 is the first preset weight value, k0 is the weight adjustment value, and k1 is the first driving weight value.

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