Liquid crystal display device and backlight driving method for the same

Abstract

To provide a liquid crystal display device and a backlight driving method for the same.SOLUTION: A liquid crystal display device 100 comprises a display panel 10 and a backlight module 20. The backlight module 20 includes a light-emitting unit, a calculation unit, a comparison unit, and a control unit. The comparison unit compares the size of a second predetermined backlight luminance value on a display screen of a frame immediately before a backlight area with the size of a first predetermined backlight luminance value on a display screen of the current frame. The control unit is caused to output a luminance drive value corresponding to a result of the comparison. The light-emitting unit emits light to a corresponding backlight area on the basis of the luminance drive value. The backlight luminance is improved on a dark part display screen of the backlight area, and detail display capability of the liquid display device 100 is improved.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to the field of display technology, and more particularly to a liquid crystal display device and a backlight driving method thereof. [Background technology]

[0002] A liquid crystal display (LCD) with a Mini Light-Emitting Diode (Mini-LED) backlight dynamically adjusts the backlight brightness of the backlight module through a local dimming (LD) algorithm to achieve ultra-high contrast of the display screen. The LD algorithm collects statistics on the brightness information of the display screen corresponding to each backlight area in the backlight module, and selects an appropriate backlight brightness based on the brightness information. The higher the brightness of an area of ​​the display screen, the higher the brightness of the corresponding backlight area. If an area of ​​the display screen is a black screen, the corresponding backlight area will not emit light. If the display screen to be displayed is a dark screen with small and scattered bright areas, such as a starry sky screen, the average brightness of the display screen and the average brightness of the corresponding backlight area are both low, the LD algorithm will obtain a backlight brightness value that is very close to zero. If the backlight precision is not high, the backlight module will eventually perform backlight output with a backlight brightness value of zero, which will cause the display details of the screen to be lost and the LCD display device to have insufficient detail display capability. Summary of the Invention [Problem to be solved by the invention]

[0003] The present application provides a liquid crystal display device and a backlight driving method thereof, which solves the problem of insufficient detail display capability when the liquid crystal display device displays a dark screen. [Means for solving the problem]

[0004] In a first aspect, the present application provides a liquid crystal display device, the liquid crystal display device comprising: a display panel including a plurality of display areas; a backlight module, the backlight module comprising: a light-emitting unit including a plurality of backlight regions corresponding to the display region; A calculation unit is used to calculate a first predetermined backlight luminance value of the backlight area corresponding to the display area according to a region average luminance value and a region maximum luminance value on a display screen of a current frame of the display area; A comparison unit is used for comparing a magnitude between a second predetermined backlight luminance value on a display screen of the backlight area in a previous frame and the first predetermined backlight luminance value, and outputting a comparison result; and a control unit used for outputting a first brightness driving value in a display screen of a current frame of the backlight area based on the comparison result, so as to cause the light-emitting unit to emit light in the backlight area based on a first brightness driving value.

[0005] In the liquid crystal display device provided by the present application, the calculation unit is used to calculate the first predetermined backlight luminance value based on the regional maximum luminance value, a first predetermined weighting value corresponding to the regional maximum luminance value, the regional average luminance value, and a second predetermined weighting value corresponding to the regional average luminance value.

[0006] In the liquid crystal display device provided by the present application, the control unit is used to output the first luminance drive value based on the region maximum luminance value, a first drive weight value corresponding to the region maximum luminance value, the region average luminance value, and a second drive weight value corresponding to the region average luminance value, wherein the first drive weight value is determined based on the first predetermined weight value and a third drive weight value corresponding to the region maximum luminance value on a display screen of the backlight region in a frame one frame before, and the second drive weight value is determined based on the second predetermined weight value and a fourth drive weight value corresponding to the region average luminance value on a display screen of the backlight region in a frame one frame before.

[0007] In the liquid crystal display device provided by the present application, the control unit is used to calculate the first luminance driving value based on a first predetermined relational expression, and the first predetermined relational expression is L(x)=k1*L_max(x)+k2*L_av(x), where L(x) is the first luminance driving value, L_max(x) is the region maximum luminance value, L_av(x) is the region average luminance value, k1 is the first driving weight value, and k2 is the second driving weight value.

[0008] In the liquid crystal display device provided by the present application, the control unit further calculates 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 predetermined relational equation, where the second predetermined relational equation is k1+k2=1.

[0009] In the liquid crystal display device provided by the present application, when the comparison result is that the first predetermined backlight luminance value and the second predetermined backlight luminance value are the same, the control unit is used to determine the third drive weight value as the first drive weight value in the display screen of the current frame in the backlight area, and to determine the fourth drive weight value as the second drive weight value in the display screen of the current frame in the backlight area.

[0010] In the liquid crystal display device provided by the present application, when the comparison result shows that the first predetermined backlight luminance value and the second predetermined backlight luminance value are different, the control unit determines whether the average gradation value in the display screen of the current frame is less than a first predetermined threshold and whether the maximum value of the backlight gradation in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold; if not, the control unit is used to determine the first predetermined weight value as the first driving weight value and the second predetermined weight value as the second driving weight value.

[0011] In the liquid crystal display device provided by the present application, the calculation unit is further used for calculating the average grayscale value on the display screen of the current frame and the maximum value of the backlight grayscale on the display screen of the current frame of all the backlight areas when the comparison result is that the first predetermined backlight luminance value and the second predetermined backlight luminance value are different.

[0012] In the liquid crystal display device provided by the present application, when the average grayscale value in the display screen of the current frame is less than a first predetermined threshold and the maximum value of the backlight grayscale in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold, the control unit is further used to determine a first driving weight value in the display screen of the current frame of the backlight area based on the first predetermined weight value and the weight adjustment value, and to determine a second driving weight value in the display screen of the current frame of the backlight area based on the second predetermined weight value and the weight adjustment value.

[0013] In the liquid crystal display device provided by the present application, the control unit is used to determine a first driving weight value in a display screen of a current frame in the backlight area based on the first predetermined weight value, the weight adjustment value, and a third predetermined relational equation, and the third predetermined relational equation is ky1+k0=k1, where ky1 is the first predetermined weight value, k0 is the weight adjustment value, and k1 is the first driving weight value in the display screen of the current frame in the backlight area.

[0014] In a second aspect, the present application further provides a backlight driving method for a liquid crystal display device, the liquid crystal display device including a display panel and a backlight module, the display panel including a plurality of display areas, and the backlight module including a plurality of backlight areas corresponding to the display areas, the backlight driving method including: Calculating a first predetermined backlight luminance value of the backlight area corresponding to the display area according to a region average luminance value and a region maximum luminance value on a display screen of a current frame of the display area; comparing a second predetermined backlight luminance value in a display screen of the backlight region in a previous frame with the first predetermined backlight luminance value, and outputting a comparison result; Outputting a first luminance driving value of a display screen of the current frame of the backlight area according to the comparison result; and controlling the backlight area to emit light based on the first luminance driving value.

[0015] In the backlight driving method provided by the present application, the step of calculating a first predetermined backlight luminance value of the backlight area corresponding to the display area according to a region average luminance value and a region maximum luminance value of a display screen of a current frame of the display area includes: Calculating an area average luminance value on a display screen of a current frame of the display area; Calculating a maximum luminance value of a region on a display screen of a current frame of the display region; and calculating the first predetermined backlight brightness value based on a first predetermined weighting value corresponding to the region maximum brightness value, a second predetermined weighting value corresponding to the region maximum brightness value, the region average brightness value, and the region maximum brightness value.

[0016] In the backlight driving method provided by the present application, the step of outputting a first luminance driving value of a display screen of the current frame of the backlight area according to the comparison result includes: determining a first drive weight value corresponding to the region maximum luminance value and a second drive weight value corresponding to the region average luminance value based on the comparison result; outputting the first luminance drive value based on the first drive weight value, the second drive weight value, the region average luminance value, and the region maximum luminance value.

[0017] In the backlight driving method provided by the present application, the step of outputting the first luminance driving value according to the first driving weight value, the second driving weight value, the area average luminance value, and the area maximum luminance value includes: outputting the first luminance driving value according to the first predetermined relational expression, the first driving weight value, the second driving weight value, the region average luminance value, and the region maximum luminance value, the first predetermined relational expression being L(x)=k1*L_max(x)+k2*L_av(x), where L(x) is the first luminance driving value, L_max(x) is the region maximum luminance value, L_av(x) is the region average luminance value, k1 is the first driving weight value, and k2 is the second driving weight value.

[0018] In the backlight driving method provided by the present application, the other 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 predetermined relational equation, and the second predetermined relational equation is k1+k2=1.

[0019] In the backlight driving method provided by the present application, the step of determining a first driving weight value corresponding to the region maximum luminance value and a second driving weight value corresponding to the region average luminance value based on the comparison result includes: When the comparison result is that the second specified backlight luminance value and the first specified backlight luminance value are the same, determining a third drive weight value corresponding to the area maximum luminance value on the display screen of the previous frame of the backlight area as the first drive weight value, and determining a fourth drive weight value corresponding to the area average luminance value on the display screen of the previous frame of the backlight area as the second drive weight value.

[0020] In the backlight driving method provided by the present application, the step of determining a first driving weight value corresponding to the region maximum luminance value and a second driving weight value corresponding to the region average luminance value based on the comparison result includes: If the comparison result is that the second predetermined backlight luminance value is different from the first predetermined backlight luminance value, determining whether or not an average grayscale value in the display screen of the current frame is less than a first predetermined threshold value and whether or not a maximum value of the backlight grayscale in the display screen of the current frame in all of the backlight areas is less than a second predetermined threshold value; If not, determining the first predetermined weight value as the first drive weight value and determining the second predetermined weight value as the second drive weight value.

[0021] In the backlight driving method provided in the present application, When the average grayscale value of the display screen of the current frame is less than a first predetermined threshold value and the maximum value of the backlight grayscale of the display screen of the current frame of all the backlight areas is less than a second predetermined threshold value, obtaining a weight adjustment value; determining the first drive weight value based on the first predetermined weight value and the weight adjustment value; The method further includes determining the second drive weight value based on the second predetermined weight value and the weight adjustment value.

[0022] In the backlight driving method provided by the present application, the step of determining the first driving weight value based on the first predetermined weight value and the weight adjustment value includes: determining the first driving weight value based on the first predetermined weight value, the weight adjustment value, and the third predetermined relational equation, the third predetermined relational equation being ky1+k0=k1, where ky1 is the first predetermined weight value, k0 is the weight adjustment value, and k1 is the first driving weight value. Effect of the Invention

[0023] In the liquid crystal display device provided by the present application, the comparison unit compares the magnitude of a second predetermined backlight luminance value in a display screen of a previous frame in the backlight area with the magnitude of a first predetermined backlight luminance value in a display screen of a current frame, thereby causing the control unit to output a luminance driving value corresponding to the comparison result, so that the light-emitting unit emits light to the corresponding backlight area based on the luminance driving value, thereby improving the backlight luminance in the dark display screen of the backlight area, and thus improving the detail display capability of the liquid crystal display device. [Brief description of the drawings]

[0024] [Figure 1]1 is a block diagram showing a liquid crystal display device according to an embodiment of the present application. [Diagram 2] FIG. 1 is a first block diagram illustrating a backlight module according to an embodiment of the present application. [Diagram 3] FIG. 2 is a second block diagram of a backlight module according to an embodiment of the present application. [Figure 4] 1 is a first flowchart showing a method for driving a liquid crystal display device according to an embodiment of the present application. [Diagram 5] 5 is a specific flowchart showing S10 in FIG. 4. [Figure 6] 5 is a second flowchart showing the method of driving the liquid crystal display device according to the embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. It should be understood that the described embodiments are merely for illustrating the ideas created by the present invention, and are not intended to limit the present application.

[0026] 1, a liquid crystal display device 100 according to this embodiment 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, and the display area includes a plurality of display areas AA1, which are used to provide a display screen, and each display area AA1 is provided with a plurality of pixels.

[0027] 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.

[0028] The light-emitting unit 201 includes a plurality of backlight areas BA1 corresponding to the display area AA1, and each backlight area BA1 is provided with a plurality of Mini-LEDs. The light-emitting unit 201 is driven by a local brightness control (Local Dimming, LD) mode. The plurality of backlight areas BA1 and the plurality of display areas AA1 have a one-to-one correspondence, that is, each display area AA1 has a corresponding backlight section BA1 that provides backlight for screen display. The entire light-emitting unit 201 is divided into a plurality of individually drivable backlight areas BA1 using the LD algorithm, and the driving current of the LEDs of the backlight areas corresponding to the corresponding parts is automatically adjusted according to the gray scale that needs to be displayed by different areas of the display screen, thereby realizing the individual adjustment of the brightness of each backlight area BA1 in the light-emitting unit 201, thereby improving the contrast of the display screen.

[0029] The calculation unit 202 is used to calculate a first predetermined backlight luminance value of the backlight area BA1 corresponding to the display area AA1 based on the area average luminance value and the area maximum luminance value on the display screen of the current frame of the display area AA1. The first predetermined backlight luminance value on the display screen of the current frame of the backlight area BA1 depends on the display luminance on the display screen of the current frame of the display area AA1 corresponding to the backlight area BA1, and the magnitude of the predetermined backlight luminance value of the backlight area BA1 depends on the magnitude of the display luminance value on the display screen of the frame corresponding to the display area AA1 corresponding to the backlight area BA1.

[0030] The calculation unit 202 obtains the luminance values ​​of all pixels in the display area AA1, determines the maximum luminance value of the pixels in the display area AA1, and determines the maximum luminance value of the pixels in the display area AA1 as the area maximum luminance value of the display area AA1.

[0031] The calculation unit 202 accumulates the brightness values ​​of all pixels in the display area AA1 to obtain a sum of the brightness values ​​of the display area AA1, and then obtains an area average brightness value of the display area AA1 based on the sum of the brightness values ​​of the display area AA1 and the number of pixels in the display area AA1.

[0032] The calculation unit 202 is further used to calculate a first predetermined backlight luminance value according to the area average luminance value of the display area AA1 corresponding to the backlight area BA1 on the display screen of the current frame, the area maximum luminance value of the same display area AA1, a first predetermined weight value, and a second predetermined weight value. Here, the first predetermined weight value is a weight value corresponding to the area maximum luminance value, and the second predetermined weight value is a weight value corresponding to the area average luminance value. Different backlight areas BA1 have the same corresponding first predetermined weight values ​​on the display screen of different frames, and different backlight areas BA1 have the same corresponding second predetermined weight values ​​on the display screen of different frames.

[0033] The first predetermined weight value is a weight value of a predetermined region maximum luminance value stored in the calculation unit 202. The second predetermined weight value is a weight value of a predetermined region average luminance value stored in the calculation unit 202.

[0034] When calculating the luminance value of the backlight area BA1 based on the LD algorithm, the luminance value of the backlight area BA1 can be adjusted by referring to the area average luminance value and the area maximum luminance value of the display screen corresponding to the backlight area BA1 and adjusting the weighting value of the area maximum luminance value and the area average luminance value accordingly. Therefore, the predetermined backlight luminance value of the corresponding backlight area BA1 can be calculated based on the first predetermined weighting value, the area maximum luminance value, the second predetermined weighting value, and the area average luminance value. Meanwhile, in the LD algorithm, when the first predetermined weighting value is increased, the luminance of all the backlight areas BA1 is improved, so that the adjustment result improves the details of the initial dark areas of the display screen, but the halation of the initial bright areas of the display screen may become severe. Therefore, the magnitude of the first predetermined weighting value should not be too large, and is preferably less than 1.

[0035] The comparison unit 203 is used to compare the magnitude of the second predetermined backlight luminance value and the first predetermined backlight luminance value on the display screen of the previous frame of the backlight area BA1, and output the comparison result. The comparison unit 203 compares the magnitude of the predetermined backlight luminance value on the display screen of two frames before and after the same backlight area BA1, and outputs the comparison result that the predetermined backlight luminance values ​​on the display screen of the two frames before and after the same backlight area BA1 are the same or different. The comparison unit 203 can further store the predetermined backlight luminance values ​​on the display screen of different frames of each backlight area BA1, thereby comparing the predetermined backlight luminance values ​​on the display screen of two frames before and after a specific backlight area BA1.

[0036] The control unit 204 is used to output a first brightness driving value of the backlight area BA1 in the display screen of the current frame based on the comparison result, so that the light-emitting unit 201 emits light in the corresponding backlight area based on the first brightness driving value, where the first brightness driving value is determined based on the second brightness driving value of the same backlight area BA1 in the display screen of the previous frame and a first predetermined backlight brightness value in the display screen of the current frame.

[0037] When the first and second predetermined backlight luminance values ​​of the same backlight area BA1 are the same, the luminance data corresponding to this backlight area BA1 does not change in the display screen of the two previous and next frames, and there is no need to adjust the detail display capability of this backlight area BA1 in the display screen of the current frame, that is, there is no need to strengthen the weighting value of the area maximum luminance value and the weighting value of the area average luminance value corresponding to this display area BA1.

[0038] When this comparison result occurs, the control unit 204 obtains the corresponding first drive weight value in the display screen of the frame immediately preceding the backlight region BA1 and the corresponding second drive weight value in the display screen of the frame immediately preceding the backlight region BA1, determines the corresponding first drive weight value in the display screen of the frame immediately preceding the backlight region BA1 as the first drive weight value in the display screen of the current frame, and determines the corresponding second drive weight value in the display screen of the frame immediately preceding the backlight region BA1 as the second drive weight value in the display screen of the current frame. That is, the backlight region BA1 has the same first drive weight value in the display screens of the two preceding and succeeding frames, and the same second drive weight value in the display screens of the two preceding and succeeding frames.

[0039] When the second predetermined backlight brightness value and the first predetermined backlight brightness value of the same backlight area BA1 are different in magnitude, the brightness data corresponding to this backlight area BA1 changes in the display screen of the two previous and next frames, and there is no need to optimize the detail display capability of this backlight area BA1 in the display screen of the current frame; that is, it is necessary to adjust the weighting value of the area maximum brightness value and the weighting value of the area average brightness value corresponding to this display area BA1.

[0040] The control unit 204 outputs the first luminance drive value based on the region maximum luminance value, the first drive weight value corresponding to the region maximum luminance value, the region average luminance value, and the second drive weight value corresponding to the region average luminance value. The first drive weight value in the display screen of the current frame of the backlight region is determined based on the first predetermined weight value and the first drive weight value corresponding to the second luminance drive value. Here, the first drive weight value is determined based on the first predetermined weight value and the third drive weight value corresponding to the region maximum luminance value in the display screen of the previous frame of the same backlight region. The second drive weight value is determined based on the second predetermined weight value and the fourth drive weight value corresponding to the region average luminance value in the display screen of the previous frame of the same backlight region. The control unit 204 can further store the drive weight value corresponding to the region maximum luminance value and the drive weight value corresponding to the region average luminance value in the display screen of each frame of each backlight region BA1, thereby comparing the drive weight values in the display screens of the two frames before and after the specific backlight region BA1.

[0041] The control unit 204 is used to calculate the first luminance drive value based on the first predetermined relational expression. The first predetermined relational expression is as follows.

[0042] L(x)=k1*L_max(x)+k2*L_av(x) (1)

[0043] In the above first predetermined relational expression (1), L(x) is the first luminance drive value, L_max(x) is the region maximum luminance value, L_av(x) is the region average luminance value, k1 is the first drive weight value in the display screen of the current frame, and k2 is the second drive weight value in the display screen of the current frame. The numerical range of k1 is 0 < k1 < 1, and the numerical range of k2 is 0 < k2 < 1.

[0044] When the regional maximum brightness value and the regional average brightness value are determined, the magnitude of the brightness driving value can be adjusted by adjusting the magnitude of the first driving weight value and / or the second driving weight value, and thus the backlight brightness of the corresponding backlight region BA1 can be adjusted, thereby improving the backlight accuracy of the corresponding backlight region BA1, ensuring that the details of the display screen of the corresponding backlight region BA1 are displayed normally, and thus improving the detail display capability of the liquid crystal display device.

[0045] The control unit 204 is further used to calculate one of the first drive weight value and the second drive weight value and the other of the first drive weight value and the second drive weight value according to a second predetermined relationship. The second predetermined relationship is as follows:

[0046] k1+k2=1 (2)

[0047] In the above relational expression (2), k1 is the first drive weight value, and k2 is the second drive weight value.

[0048] The control unit 204 outputs a corresponding brightness driving value so that the light-emitting unit 201 emits light in the backlight area based on the brightness driving value, based on a comparison result that the predetermined backlight brightness values ​​in the display screen of the two frames before and after the same backlight area BA1 are the same. The control unit 204 outputs a corresponding brightness driving value so that the light-emitting unit 201 emits light in the backlight area based on the brightness driving value, based on a comparison result that the predetermined backlight brightness values ​​in the display screen of the two frames before and after the same backlight area BA1 are different.

[0049] 3, in the liquid crystal display device 100 of this embodiment, the backlight module 20 further includes a storage unit 205, which is used for storing predetermined backlight luminance values ​​in different frames of the display screen of each backlight area BA1 in real time, so as to provide the predetermined backlight luminance values ​​in the display screen of the frame with the backlight area BA1 to the comparison unit 203 in real time. The storage unit 205 is further used for storing driving weight values ​​corresponding to the region maximum luminance value and the region average luminance value in the display screen of each frame of each area BA1 in real time, so as to provide the corresponding driving weight values ​​in the display screen of the frame with the backlight area BA1 to the control unit 204 in real time.

[0050] In the present liquid crystal display device 100, the comparison unit 203 compares the magnitude of a predetermined backlight luminance value in the display screen of the previous frame of the backlight area BA1 with a predetermined backlight luminance value in the display screen of the current frame, and causes the control unit 204 to output a luminance driving value corresponding to the comparison result, so that the light-emitting unit 201 emits light in the corresponding backlight area based on the luminance driving value, thereby improving the backlight luminance in the dark area display screen of the backlight area BA1, and ultimately improving the detail display capability of the liquid crystal display device.

[0051] In the liquid crystal display device provided by the present application, when the comparison result shows that the predetermined backlight luminance values ​​on the display screen of the same backlight area BA1 are different between the previous and next two frames, i.e., when the first predetermined backlight luminance value and the second predetermined backlight luminance value are different, the calculation unit 202 is further used to calculate the average grayscale value on the display screen of the current frame of the display panel 10 and the maximum backlight grayscale value on the display screen of the current frame of all the backlight areas BA1.

[0052] The calculation unit 202 obtains the grayscale values ​​of all pixels in all display areas AA1 on the display screen of the current frame, accumulates the brightness values ​​of all pixels to obtain the sum of the grayscale values ​​of the display panel 10, and obtains the average grayscale value of the display screen of the current frame of the display panel 10 based on the sum of the grayscale values ​​of the display panel 10 and the total number of pixels of the display panel 10.

[0053] The calculation unit 202 obtains the grayscale values ​​of all Mini-LEDs in all backlight areas BA1 on the display screen of the current frame, and determines the maximum grayscale values ​​of the Mini-LEDs in all backlight areas BA1.

[0054] The control unit 204 is further used to determine whether the average grayscale value on the display screen of the current frame of the display panel 10 is less than a first predetermined threshold, and whether the maximum value of the backlight grayscale on the display screen of the current frame of all the backlight areas BA1 is less than a second predetermined threshold.

[0055] When the average gray scale value of the display screen of the current frame of the display panel 10 is greater than or equal to the first predetermined threshold, the average brightness of the display screen of the current frame is relatively high, and the Mini-LEDs in the light-emitting unit 201 are all turned on or only a few of them are turned off on the display screen of the current frame.

[0056] Therefore, there is no need to adjust the brightness of the backlight area BA1 again, and there is no need to optimize the detail display ability of the backlight area BA1 on the display screen of the current frame, that is, there is no need to adjust the weight value of the area maximum brightness value and the weight value of the area average brightness value corresponding to the backlight area BA1. According to the judgment result, the control unit 204 determines the first predetermined weight value as the first driving weight value and the second predetermined weight value as the second driving weight value, so that the magnitude of the first predetermined backlight brightness value of the backlight area BA1 is the same as the magnitude of the first light-emitting driving value of the backlight area BA1, and the light-emitting unit 201 emits light in the corresponding backlight area BA1 on the display screen of the current frame according to the first predetermined backlight brightness value.

[0057] When the average grayscale value in the display screen of the current frame of the display panel 10 is less than the first set threshold value but the maximum value of the backlight grayscale in the display screen of the current frame of all backlight areas BA1 is equal to or greater than the second predetermined threshold value, the average luminance in the display screen of the current frame is relatively low and the peak luminance in the display screen of the current frame is relatively high, so that a backlight area BA1 with high backlight luminance exists, and a light diffusion phenomenon occurs in the backlight area BA1 due to the relatively high backlight luminance, while the light diffusion phenomenon improves the ability to display details in dark areas around the backlight area BA1 where the backlight luminance is relatively high.

[0058] Therefore, there is no need to adjust the brightness of the backlight area BA1 having a relatively high backlight brightness again, and there is no need to optimize the detail display ability of the backlight area BA1 on the display screen of the current frame, that is, there is no need to adjust the weight value of the area maximum brightness value and the weight value of the area average brightness value corresponding to the backlight area BA1. According to the judgment result, the control unit 204 determines the first predetermined weight value as the first driving weight value and the second predetermined weight value as the second driving weight value, so that the magnitude of the first predetermined backlight brightness value of the backlight area BA1 is the same as the magnitude of the first light-emitting driving value of the backlight area BA1, and the light-emitting unit 201 emits light in the corresponding backlight area BA1 on the display screen of the current frame according to the first predetermined backlight brightness value.

[0059] When the average gray scale value of the display screen of the current frame of the display panel 10 is less than a first predetermined threshold value and the maximum value of the backlight gray scale of the display screen of the current frame of all backlight areas BA1 is less than a second predetermined threshold value, the overall brightness of all backlight areas BA1 is relatively low or the Mini-LEDs of all backlight areas BA1 are all off. In order to ensure that the display area AA1 corresponding to this backlight area BA1 can perform detailed display, in this case, it is necessary to improve the detailed display capability of this backlight area BA1.

[0060] According to this determination result, the control unit 204 further determines, based on the first predetermined weight value and the weight adjustment value, a new first driving weight value on the display screen of the current frame in the backlight area BA1, and determines, based on the second predetermined weight value and the weight adjustment value, a new second driving weight value on the display screen of the current frame in the same backlight area.

[0061] The specific numerical value of the weight adjustment value is determined by experimental debugging. The control unit 204 determines the first driving weight value based on the first predetermined weight value, the weight adjustment value determined by debugging, and the third predetermined relational expression. The third predetermined relational expression is as follows.

[0062] ky1 + k0 = k1 (3)

[0063] In the above third predetermined relational expression (3), ky1 is the first predetermined weight value, k0 is the weight adjustment value, and k1 is the first driving weight value. Here, the specific numerical range of the weight adjustment value k0 is 0 < k0 < 1 - ky1. In order to improve the detailed display ability of the dark part display screen corresponding to the backlight area BA1, it is necessary to improve the weight value corresponding to the maximum area luminance value of this backlight area. Therefore, preferably, the weight adjustment value is greater than 0. At the same time, in order to avoid the expansion of the halation of the corresponding display screen after the backlight area BA1 is over-dimmed, it is preferable that the first driving weight value k1 that can be calculated based on the first predetermined weight value ky1 and the weight adjustment value k0 is less than 1. That is, the weight adjustment value should satisfy both being greater than 0 and less than the difference value between 1 and the first predetermined weight value ky1.

[0064] Since the newly determined first drive weight value and the corresponding second drive weight value need to satisfy the above-mentioned second predetermined relational expression (2), the corresponding second drive weight value can be calculated based on the newly determined first drive weight value and the second predetermined relational expression (2). Then, the luminance drive value of the corresponding backlight area on the display screen of the current frame can be calculated based on the first predetermined relational expression (1), the newly determined first drive weight value, the corresponding second drive weight value, the area average luminance value of the backlight area, and the area maximum luminance value.

[0065] In the present liquid crystal display device 100, the control unit 204 further determines the relationship between the average grayscale value in the display screen of the current frame and the first predetermined threshold value, and the relationship between the maximum backlight grayscale value in the display screen of the current frame of all backlight areas and the second predetermined threshold value, thereby improving the display brightness in the dark display screen of the backlight area BA1, thereby improving the detail display capability of the liquid crystal display device and avoiding the expansion of halation on the corresponding display screen due to excessive dimming of the backlight area BA1.

[0066] As shown in FIG. 4 , an embodiment of the present application further provides a backlight driving method for a liquid crystal display device, where the liquid crystal display device of this embodiment includes a display panel and a backlight module, the display panel includes a plurality of display areas, and the backlight module includes a plurality of backlight areas corresponding to the display areas, and the backlight driving method of this embodiment includes the following steps:

[0067] In step S10, a first predetermined backlight luminance value of the backlight area corresponding to the display area is calculated based on the area average luminance value and the area maximum luminance value of the display area on the display screen of the current frame. As shown in FIG. 5, step S10 specifically includes:

[0068] In S101, the average luminance value of the display area in the current frame of the display screen is calculated. The luminance values ​​of all pixels in the display area are accumulated to obtain the sum of the luminance values ​​of the display area, and the sum of the luminance values ​​of the display area AA1 is divided by the number of pixels in the display area to obtain the average luminance value of the display area.

[0069] In S102, the maximum luminance value of the display area in the display screen of the current frame is calculated. The luminance values ​​of all pixels in the display area are acquired, and the maximum luminance value of the pixels in this display area is determined as the maximum luminance value of the display area.

[0070] In S103, a first predetermined backlight luminance value is calculated based on a first predetermined weight value corresponding to the regional maximum luminance value, a second predetermined weight value corresponding to the regional maximum luminance value, the regional average luminance value, and the regional maximum luminance value.

[0071] In S20, the second predetermined backlight luminance value in the display screen of the previous frame of the backlight area is compared with the first predetermined backlight luminance value, and the comparison result is output, that is, it is compared whether the magnitude between the predetermined backlight luminance values ​​of the two frames before and after the same backlight area is the same.

[0072] There are two comparison results in step S20: the first comparison result is that the second predetermined backlight luminance value and the first predetermined backlight luminance value have the same magnitude, and the second comparison result is that the second predetermined backlight luminance value and the first predetermined backlight luminance value have different magnitudes.

[0073] In S30, based on the comparison result, output a first luminance driving value for the display screen of the current frame in the backlight area.

[0074] The backlight driving method for a liquid crystal display device provided in this embodiment compares the magnitude of a predetermined backlight luminance in a display screen of a previous frame in the backlight area with a predetermined backlight luminance value in a display screen of a current frame in the backlight area, and determines a first luminance driving value in the display screen of the current frame in the backlight area based on the comparison result, thereby improving the display luminance in the dark display screen of the backlight area and improving the detail display capability of the liquid crystal display device.

[0075] As shown in FIG. 4 and FIG. 6, step S30 may specifically include steps S301 and S302.

[0076] In S301, a first drive weight value corresponding to the area maximum luminance value and a second drive weight value corresponding to the area average luminance value are determined based on the comparison result.

[0077] Step S301 may specifically include:

[0078] In S3011, if the comparison result is that the second specified backlight luminance value and the first specified backlight luminance value are the same, a third drive weight value corresponding to the maximum luminance value on the display screen of the previous frame in this backlight area is determined as the first drive weight value, and a fourth drive weight value corresponding to the average luminance value on the display screen of the previous frame in this backlight area is determined as the second drive weight value.

[0079] In S3012, if the comparison result shows that the second predetermined backlight luminance value is different from the first predetermined backlight luminance value, it is determined whether or not the average gradation value on the display screen of the current frame is less than the first predetermined threshold value and whether or not the maximum value of the backlight gradation on the display screen of the current frame of all backlight areas is less than the second predetermined threshold value, and the first drive weight value and the second drive weight value are determined according to the determination result.

[0080] Step S3012 may further include:

[0081] In S30121, if not satisfied, the first predetermined weight value is determined as the first drive weight value, and the second predetermined weight value is determined as the second drive weight value.

[0082] In S30122, if the above conditions are satisfied, i.e., if the average gradation value on the display screen of the current frame is less than the first predetermined threshold and the maximum value of the backlight gradation on the display screen of the current frame of all backlight areas is less than the second predetermined threshold, a weight adjustment value is obtained, and a first driving weight value is determined based on the first predetermined weight value and the weight adjustment value, and a second driving weight value is determined based on the second predetermined weight value and the weight adjustment value.

[0083] In step S30122, a first driving weight value can be determined based on the first predetermined weight value, the weight adjustment value, and a third predetermined relational expression.

[0084] ky1+k0=k1 (3)

[0085] In the third predetermined relational expression (3), ky1 is the first predetermined weight value, k0 is the weight adjustment value, and k1 is the first driving weight value. Here, the specific numerical range of the weight adjustment value k0 is 0. <k0<1-ky1である。

[0086] In S302, a first luminance drive value is output based on the first drive weight value, the second drive weight value, the region average luminance value, and the region maximum luminance value.

[0087] In step S302, the first brightness driving value can be output based on a first predetermined relationship, a first driving weight value, a second driving weight value, a region average brightness value, and a region maximum brightness value, where the first predetermined relationship is as follows:

[0088] L(x)=k1*L_max(x)+k2*L_av(x) (1)

[0089] In the above first predetermined relational expression (1), L(x) is the first luminance driving value, L_max(x) is the maximum luminance value of the region, L_av(x) is the average luminance value of the region, k1 is the first driving weight value, and k2 is the second driving weight value. The numerical range of k1 is 0 < k1 < 1, and the numerical range of k2 is 0 < k2 < 1.

[0090] In step S302, further, based on one of the first driving weight value and the second driving weight value, and the second predetermined relational expression, the value of the other of the first driving weight value and the second driving weight value can be calculated. The second predetermined relational expression is as follows.

[0091] k1 + k2 = 1 (2)

[0092] In the above relational expression (2), k1 is the first driving weight value, and k2 is the second driving weight value.

[0093] In S40, the light emission of the backlight region is controlled based on the first luminance driving value.

[0094] The backlight driving method of the liquid crystal display device provided by the embodiment of the present application determines the magnitude relationship between the average gradation value in the display screen of the current frame and the first predetermined threshold value, and the magnitude relationship between the maximum backlight gradation value in the display screen of the current frame of all backlight regions and the second predetermined threshold value, and according to the determination result, determines the first luminance driving value in the display screen of the current frame of the backlight region, thereby improving the display luminance in the dark part display screen of the backlight region, improving the detail display ability of the liquid crystal display device, and avoiding the expansion of halation in the corresponding display screen caused by over-dimming the backlight region.

[0095] Of course, the present application can also provide various other embodiments. However, on the premise of not departing from the idea and the essential gist of the present application, those skilled in the art can make various changes and deformations according to the present application. However, these corresponding changes and deformations shall be included in the scope of the claims of the present application.

Explanation of Reference Numerals

[0096] 10: Display panel 20: Backlight module 100:Liquid crystal display device 201: Light emitting unit 202: Calculation unit 203: Comparison unit 204: Control unit 205: Storage unit

Claims

1. a display panel including a plurality of display areas; a backlight module; The backlight module includes: a light-emitting unit including a plurality of backlight regions corresponding to the display region; a calculation unit used to calculate a first predetermined backlight luminance value of the backlight area corresponding to the display area according to a region average luminance value and a region maximum luminance value on a display screen of a current frame of the display area; A comparison unit is used for comparing a magnitude of a second predetermined backlight luminance value on a display screen of the backlight area in a previous frame with the first predetermined backlight luminance value, and outputting a comparison result; A control unit is used for outputting a first luminance driving value in a display screen of a current frame of the backlight area according to the comparison result, so as to make the light-emitting unit emit light in the backlight area according to a first luminance driving value. LCD display device.

2. the calculation unit is used to calculate the first predetermined backlight luminance value according to the regional maximum luminance value, a first predetermined weighting value corresponding to the regional maximum luminance value, the regional average luminance value, and a second predetermined weighting value corresponding to the regional average luminance value; The liquid crystal display device according to claim 1 .

3. The control unit is used to output the first luminance drive value based on the region maximum luminance value, a first drive weight value corresponding to the region maximum luminance value, the region average luminance value, and a second drive weight value corresponding to the region average luminance value, wherein the first drive weight value is determined based on the first predetermined weight value and a third drive weight value corresponding to the region maximum luminance value on a display screen of the backlight region in a previous frame, and the second drive weight value is determined based on the second predetermined weight value and a fourth drive weight value corresponding to the region average luminance value on a display screen of the backlight region in a previous frame. The liquid crystal display device according to claim 2 .

4. The control unit is used to calculate the first luminance drive value based on a first predetermined relationship, the first predetermined relationship being L(x)=k1*L_max(x)+k2*L_av(x), where L(x) is the first luminance drive value, L_max(x) is the region maximum luminance value, L_av(x) is the region average luminance value, k1 is the first drive weight value, and k2 is the second drive weight value. The liquid crystal display device according to claim 3 .

5. The control unit further calculates the other of the first drive weight value and the second drive weight value based on one of the first drive weight value and the second drive weight value and a second predetermined relational expression, wherein the second predetermined relational expression is k1+k2=1. The liquid crystal display device according to claim 4 .

6. When the comparison result is that the first predetermined backlight luminance value and the second predetermined backlight luminance value are the same, the control unit determines the third driving weight value as a first driving weight value in a display screen of a current frame in the backlight area, and determines the fourth driving weight value as a second driving weight value in a display screen of a current frame in the backlight area. The liquid crystal display device according to claim 3 .

7. the control unit, when the comparison result shows that the first predetermined backlight luminance value is different from the second predetermined backlight luminance value, judges whether an average grayscale value in the display screen of the current frame is less than a first predetermined threshold value and whether a maximum value of the backlight grayscale in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold value; if not, determines the first predetermined weight value as the first driving weight value and uses the second predetermined weight value as the second driving weight value; The liquid crystal display device according to claim 3 .

8. The calculation unit is further used to calculate the average gray level value on the display screen of the current frame and the maximum value of the backlight gray level on the display screen of the current frame of all the backlight areas when the comparison result is different between the first predetermined backlight luminance value and the second predetermined backlight luminance value. The liquid crystal display device according to claim 7.

9. When the average grayscale value in the display screen of the current frame is less than a first predetermined threshold value and the maximum value of the backlight grayscale in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold value, the control unit is further used to determine a first driving weight value in the display screen of the current frame of the backlight area based on the first predetermined weight value and the weight adjustment value, and to determine a second driving weight value in the display screen of the current frame of the backlight area based on the second predetermined weight value and the weight adjustment value. The liquid crystal display device according to claim 7.

10. The control unit is used to determine a first driving weight value of a display screen of a current frame of the backlight area according to the first predetermined weight value, the weight adjustment value, and a third predetermined relational equation, and the third predetermined relational equation is k y1 + k 0 = k 1, where k y1 is the first predetermined weight value, k 0 is the weight adjustment value, and k 1 is the first driving weight value of a display screen of a current frame of the backlight area; The liquid crystal display device according to claim 9 .

11. A backlight driving method for a liquid crystal display device, the liquid crystal display device including a display panel and a backlight module, the display panel including a plurality of display areas, and the backlight module including a plurality of backlight areas corresponding to the display areas, the backlight driving method comprising: Calculating a first predetermined backlight luminance value of the backlight area corresponding to the display area according to a region average luminance value and a region maximum luminance value on a display screen of a current frame of the display area; comparing a second predetermined backlight luminance value in a display screen of the backlight region in a previous frame with the first predetermined backlight luminance value, and outputting a comparison result; Outputting a first luminance driving value of a display screen of the current frame of the backlight area according to the comparison result; and controlling the backlight area to emit light based on the first luminance driving value. Backlight driving method.

12. The step of calculating a first predetermined backlight luminance value of the backlight area corresponding to the display area based on a region average luminance value and a region maximum luminance value on a display screen of a current frame of the display area, Calculating an area average luminance value on a display screen of a current frame of the display area; Calculating a maximum luminance value of a region on a display screen of a current frame of the display region; calculating the first predetermined backlight luminance value based on a first predetermined weighting value corresponding to the regional maximum luminance value, a second predetermined weighting value corresponding to the regional maximum luminance value, the regional average luminance value, and the regional maximum luminance value. The backlight driving method according to claim 11.

13. The step of outputting a first luminance driving value of the display screen of the current frame of the backlight area according to the comparison result includes: determining a first drive weight value corresponding to the region maximum luminance value and a second drive weight value corresponding to the region average luminance value based on the comparison result; outputting the first luminance drive value based on the first drive weight value, the second drive weight value, the region average luminance value, and the region maximum luminance value. The backlight driving method according to claim 11.

14. outputting the first luminance drive value based on the first drive weight value, the second drive weight value, the region average luminance value, and the region maximum luminance value, outputting the first luminance driving value according to a first predetermined relational expression, the first driving weight value, the second driving weight value, the region average luminance value, and the region maximum luminance value, the first predetermined relational expression being L(x)=k1*L_max(x)+k2*L_av(x), where L(x) is the first luminance driving value, L_max(x) is the region maximum luminance value, L_av(x) is the region average luminance value, k1 is the first driving weight value, and k2 is the second driving weight value; The backlight driving method according to claim 13.

15. Calculating the other of the first drive weight value and the second drive weight value based on one of the first drive weight value and the second drive weight value and a second predetermined relational expression, wherein the second predetermined relational expression is k1+k2=1. The backlight driving method according to claim 14.

16. determining a first drive weight value corresponding to the region maximum luminance value and a second drive weight value corresponding to the region average luminance value based on the comparison result, determining, when the comparison result indicates that the second predetermined backlight luminance value is the same as the first predetermined backlight luminance value, a third drive weight value corresponding to the region maximum luminance value on the display screen of the previous frame of the backlight region as the first drive weight value, and determining, as the second drive weight value, a fourth drive weight value corresponding to the region average luminance value on the display screen of the previous frame of the backlight region. The backlight driving method according to claim 13.

17. determining a first drive weight value corresponding to the region maximum luminance value and a second drive weight value corresponding to the region average luminance value based on the comparison result, If the comparison result is that the second predetermined backlight luminance value is different from the first predetermined backlight luminance value, determining whether or not an average grayscale value in the display screen of the current frame is less than a first predetermined threshold value and whether or not a maximum value of the backlight grayscale in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold value; if not, determining a first predetermined weight value as the first drive weight value and determining a second predetermined weight value as the second drive weight value. The backlight driving method according to claim 13.

18. When the average gray level value in the display screen of the current frame is less than a first predetermined threshold value and the maximum value of the backlight gray level in the display screen of the current frame of all the backlight areas is less than a second predetermined threshold value, obtaining a weight adjustment value; determining the first drive weight value based on the first predetermined weight value and the weight adjustment value; determining the second drive weight value based on the second predetermined weight value and the weight adjustment value. The backlight driving method according to claim 17.

19. The step of determining the first drive weight value based on the first predetermined weight value and the weight adjustment value includes: determining the first driving weight value according to the first predetermined weight value, the weight adjustment value, and a third predetermined relational expression, the third predetermined relational expression being k y1 + k 0 = k 1 , where k y1 is the first predetermined weight value, k 0 is the weight adjustment value, and k 1 is the first driving weight value; The backlight driving method according to claim 18.

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