Liquid crystal display low power consumption driving method fusing content perception and area backlight modulation

Abstract

The application discloses a liquid crystal display low-power consumption driving method fusing content perception and area backlight modulation, relates to the technical field of liquid crystal display driving, and comprises the following steps: obtaining target luminance data of a frame to be displayed, and obtaining optical coupling response from backlight partition to liquid crystal pixel sampling position in a liquid crystal display module and available transmittance range of the liquid crystal pixel; determining content constraint information according to spatial luminance variation and interframe luminance variation of the target luminance data; determining backlight feasible conditions corresponding to the target luminance of each pixel within the liquid crystal compensation capability range according to the optical coupling response, the target luminance data and the available transmittance range; and determining backlight feasible conditions corresponding to the luminance compensation that can be completed by each pixel according to the target luminance, the available transmittance range of the liquid crystal pixel and the optical coupling response from the backlight partition to the liquid crystal pixel, so that the process of reducing backlight power consumption is limited by the actual compensation capability of the liquid crystal.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal display driving technology, and more specifically, to a low-power driving method for liquid crystal displays that integrates content awareness and regional backlight modulation. Background Technology

[0002] Liquid crystal displays (LCDs) typically utilize backlight modules to provide illumination and adjust the transmittance of the backlight through a liquid crystal layer to create brightness and grayscale corresponding to the image to be displayed. For LCDs employing direct-lit LED or Mini-LED backlighting, the backlight module can be divided into multiple independently driveable backlight zones. The driving intensity of each backlight zone can be adjusted according to the brightness requirements of different areas of the image to be displayed, thereby reducing backlight power consumption in areas where high brightness is not required. Therefore, local dimming has become an important driving method that balances LCD contrast ratio and overall power consumption.

[0003] Existing local dimming backlighting methods typically determine the driving amount of a backlight zone based on the maximum brightness, average brightness, or grayscale statistics of the image area corresponding to that backlight zone. They then increase the transmittance of the corresponding liquid crystal pixels after reducing backlight brightness to compensate for the loss of display brightness caused by the reduced backlight. Some driving methods also adjust the driving amount of the backlight zone based on image edges, brightness distribution, or visually significant areas to reduce the impact of local dimming on image display quality.

[0004] However, there is no strict one-to-one correspondence between backlight zones and liquid crystal pixels. Light generated by one backlight zone diffuses into the surrounding area after passing through the diffuser, light guide, and other optical films. The backlight received by the same liquid crystal pixel may also come from multiple backlight zones simultaneously. Therefore, determining the backlight drive amount of a zone solely based on the image brightness within that zone is insufficient to reflect the actual spatial optical coupling relationship of the backlight module. When high-brightness and low-brightness areas are located in adjacent or optically strongly coupled backlight zones, the diffused light generated by the high-brightness zone may enter the dark area, causing the actual backlight brightness obtained in the dark area to exceed the target requirement, resulting in halos, increased black levels, or decreased local contrast. Summary of the Invention

[0005] To overcome the above-mentioned defects of the prior art, the present invention provides a low-power driving method for liquid crystal displays that integrates content awareness and regional backlight modulation. By pre-determining the backlight feasibility conditions corresponding to each pixel being able to complete brightness compensation based on the target brightness, the available transmittance range of the liquid crystal pixels, and the optical coupling response from the backlight partition to the liquid crystal pixels, the process of reducing backlight power consumption is limited by the actual compensation capability of the liquid crystal.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A low-power driving method for liquid crystal displays that integrates content-aware and local backlight modulation includes the following steps: The target brightness data of the frame to be displayed is obtained, and the optical coupling response from the backlight partition to the sampling position of the liquid crystal pixel in the liquid crystal display module and the available transmittance range of the liquid crystal pixel are obtained; content constraint information is determined based on the spatial brightness change and inter-frame brightness change of the target brightness data. Based on the optical coupling response, target brightness data, and the available transmittance range of the liquid crystal pixels, determine the backlight feasibility conditions for each pixel to achieve the target brightness within the liquid crystal compensation capability range. A partition coupling relationship is established based on the optical coupling relationship between the backlight partitions, and the light leakage limitation condition corresponding to the high contrast boundary is determined according to the content constraint information. Under the condition that both the backlight feasibility condition and the light leakage limitation condition are met, the driving amount of each backlight zone is determined with the optimization goal of reducing backlight power consumption. The actual backlight brightness field at the liquid crystal panel is reconstructed based on the driving amount of each backlight zone and the optical coupling response. The transmittance of the liquid crystal pixels is determined based on the target brightness data and the actual backlight brightness field. Pixel driving data is generated based on the liquid crystal electro-optic response relationship. The pixel driving data and the corresponding backlight zone driving data are output synchronously.

[0007] Preferably, the step of determining content constraint information based on the spatial brightness change and inter-frame brightness change of the target brightness data includes: converting the image data corresponding to the frame to be displayed to a linear optical domain for backlight brightness calculation; calculating the local brightness gradient and local brightness dynamic range corresponding to each pixel or pixel block based on the target brightness data in the linear optical domain, and determining the inter-frame brightness residual based on the brightness difference between the current frame to be displayed and the corresponding position of the previous frame; determining the degree of spatial structure preservation at the corresponding position based on the local brightness gradient and local brightness dynamic range, and determining the degree of temporal change at the corresponding position based on the inter-frame brightness residual; and, based on the degree of spatial structure preservation and the degree of temporal change, dividing the pixels participating in the backlight constraint calculation into at least brightness-preserving pixels and pixels that are allowed to compensate for deviations, and setting brightness deviation tolerances for different categories of pixels, wherein the brightness deviation tolerance corresponding to brightness-preserving pixels located on both sides of high contrast contours or in local bright areas is less than the brightness deviation tolerance corresponding to pixels that are allowed to compensate for deviations.

[0008] By setting the above, the content perception result can be transformed into different brightness maintenance requirements in the subsequent backlight solution process instead of directly corresponding to a fixed backlight adjustment coefficient. This allows display areas with different spatial structural importance and time-varying states to adopt different backlight constraint intensities.

[0009] Preferably, the optical coupling response is characterized by a partitioned optical response matrix, wherein the matrix elements in the partitioned optical response matrix represent the brightness contribution of a backlight partition to a liquid crystal pixel sampling position under a predetermined driving state.

[0010] The partitioned optical response matrix can be obtained by driving each backlight partition in the backlight module and collecting the brightness response generated by multiple liquid crystal pixel sampling positions; or it can be obtained by obtaining the light distribution function corresponding to each backlight partition and discretizing the light distribution function according to the pixel sampling position in the liquid crystal panel.

[0011] During the display driving process, the driving quantity corresponding to each backlight zone is mapped to the optical response matrix of the zone, and the brightness contribution of each backlight zone to different liquid crystal pixel positions is superimposed to obtain the actual spatial backlight brightness field at the position of the liquid crystal panel.

[0012] Preferably, determining backlight feasibility conditions based on the optical coupling response, target brightness data, and available transmittance range of liquid crystal pixels includes: determining the minimum incident backlight brightness required for a pixel to recover the target display brightness based on the maximum available transmittance of each liquid crystal pixel and the target brightness of the corresponding pixel; determining at least one associated backlight zone that can provide incident backlight to the pixel based on the partition optical response matrix; establishing a correspondence between the driving amount of the associated backlight zone and the incident backlight brightness of the pixel based on the brightness contribution of each associated backlight zone to the pixel; limiting the incident backlight brightness formed by each associated backlight zone to no less than the minimum incident backlight brightness minus the allowable brightness deviation of the corresponding pixel; and jointly determining the backlight feasibility domain corresponding to the current frame to be displayed based on the above-mentioned limiting relationship formed by multiple liquid crystal pixels.

[0013] Therefore, before performing the calculation to reduce backlight power consumption, the physical boundary for further backlight reduction can be determined based on the transmittance range that the liquid crystal pixels themselves can achieve, so that the subsequently determined backlight driving state remains within the range that the liquid crystal pixels can effectively compensate for.

[0014] Preferably, establishing a partition coupling relationship based on the optical coupling relationship between backlight partitions includes: determining the spatial light distribution formed by different backlight partitions according to the partition optical response matrix; calculating the degree of overlap between the spatial light distributions corresponding to any two backlight partitions, and establishing a partition coupling relationship between the corresponding two backlight partitions when the degree of overlap meets a preset coupling condition; determining the position of the high contrast boundary according to the content constraint information of the frame to be displayed, and determining the partition coupling relationship that crosses the high contrast boundary; calculating the predicted light leakage brightness generated on the dark side of the high contrast boundary according to the optical response of the backlight partition corresponding to the bright side of the high contrast boundary and the candidate driving quantity of the backlight partition; determining the upper limit of light leakage according to the target brightness of the dark side pixel and the corresponding brightness deviation tolerance, and limiting the predicted light leakage brightness to not exceed the upper limit of light leakage, thereby forming the light leakage constraint condition corresponding to the high contrast boundary.

[0015] By determining the coupling relationship between zones based on the actual optical response, the deviation caused by determining the adjacency relationship based solely on the geometric position of the backlight zones can be avoided, and drive constraints can be established for backlight zones that can actually generate optical crosstalk to the other side of the high contrast boundary.

[0016] Preferably, determining the driving quantity of each backlight zone while simultaneously satisfying the backlight feasibility condition and the light leakage limitation condition includes: obtaining the calibration relationship between different backlight driving quantities and the corresponding LED driving power, and establishing the power consumption function corresponding to each backlight zone according to the calibration relationship; establishing the backlight power consumption target corresponding to the current frame to be displayed according to the power consumption functions of multiple backlight zones; taking the reduction of the backlight power consumption target as the optimization direction, incorporating the backlight feasibility condition corresponding to the brightness-maintaining pixel, the brightness deviation condition corresponding to the allowed compensation deviation pixel, and the light leakage limitation condition corresponding to the high contrast boundary into the solution process of the backlight driving quantity, to obtain at least one candidate backlight driving vector that satisfies the limitation conditions; when there are multiple candidate backlight driving vectors that satisfy the limitation conditions, determining the target backlight driving vector according to the backlight power consumption corresponding to each candidate backlight driving vector.

[0017] Therefore, the reduction in backlight power consumption is not independent of display quality, but is achieved within the allowable range determined by both liquid crystal compensation capability and optical crosstalk limitation.

[0018] Preferably, in order to improve the backlight stability in continuous video frames, the content change amount of each backlight partition is determined according to the brightness residual between the current frame and the previous frame, and the inter-frame change limit of the driving amount of each backlight partition is set according to the content change amount.

[0019] When the content change of the area corresponding to a backlight partition is less than the first change threshold, the change of the backlight drive amount of the current display frame relative to the backlight drive amount of the previous display frame is restricted; when the content change amount is greater than the second change threshold and the scene switching condition is met, the inter-frame change restriction of the corresponding backlight partition is expanded or canceled; the inter-frame change restriction, backlight feasibility condition and light leakage restriction condition are added together to the backlight drive solution process of the current display frame.

[0020] By directly incorporating the inter-frame variation constraint into the backlight driving quantity solution process, the obtained backlight driving state can simultaneously meet the liquid crystal compensation requirements and time stability requirements, reducing the mismatch between the backlight state and the liquid crystal compensation state caused by performing smoothing processing on the solved backlight driving quantity separately.

[0021] Preferably, determining the transmittance of a liquid crystal pixel based on the actual backlight brightness field includes: determining the target transmittance of the liquid crystal pixel based on the relationship between the target brightness of each liquid crystal pixel and the actual backlight brightness at the corresponding pixel position; comparing the target transmittance with the available transmittance range of the corresponding liquid crystal pixel; when the target transmittance is within the available transmittance range, determining the pixel driving data corresponding to the target transmittance based on the liquid crystal electro-optic response relationship; when the target transmittance exceeds the maximum available transmittance, determining the corresponding liquid crystal pixel as a compensation mismatch pixel, and determining the associated backlight partition that contributes to the brightness of the compensation mismatch pixel based on the partition optical response matrix; increasing the backlight driving lower limit corresponding to at least one of the associated backlight partitions, and re-determining the backlight partition driving amount that has an optical coupling relationship with the associated backlight partition; reconstructing the actual backlight brightness field and determining the target transmittance corresponding to the compensation mismatch pixel, until the compensation mismatch pixel meets the corresponding brightness deviation tolerance or reaches the preset iteration termination condition.

[0022] In this way, when the actual backlight state is found to be insufficient in terms of liquid crystal compensation capability, the mismatch result on the liquid crystal side can be fed back to the backlight driving solution process, instead of directly limiting the liquid crystal grayscale to the maximum grayscale, thereby establishing a closed-loop correction relationship between backlight driving and liquid crystal compensation.

[0023] Preferably, the backlight zone driving data includes the pulse width modulation duty cycle and / or LED driving current amplitude corresponding to each backlight zone, and the pixel driving data includes TFT grayscale data determined according to the liquid crystal electro-optic response relationship.

[0024] According to the same display frame correspondence, the target backlight driving vector is converted into backlight partition driving data and written into the backlight driving circuit. The TFT grayscale data determined according to the corresponding actual backlight brightness field is written into the liquid crystal panel driving circuit, so that the actual transmittance of the liquid crystal pixel and the actual backlight brightness at the corresponding position together form the display brightness required by the frame to be displayed.

[0025] The present invention also provides a low-power driving system for liquid crystal displays that integrates content awareness and local backlight modulation, including an image processing unit, a backlight control unit, a liquid crystal compensation unit, and a storage unit. The storage unit is used to store the optical coupling response from the backlight partition to the sampling position of the liquid crystal pixel and the electro-optic response parameters corresponding to the liquid crystal pixel; The image processing unit is used to determine content constraint information based on the target brightness data of the frame to be displayed. The backlight control unit is used to determine backlight feasibility conditions based on target brightness data, the optical coupling response, and the available transmittance range of liquid crystal pixels; determine light leakage limitation conditions corresponding to high contrast boundaries based on the optical coupling relationship between backlight zones; and determine the driving amount of each backlight zone when the backlight feasibility conditions and light leakage limitation conditions are met. The liquid crystal compensation unit is used to reconstruct the actual backlight brightness field based on the driving amount of each backlight zone and the optical coupling response, and to generate liquid crystal pixel driving data based on the target brightness data and the actual backlight brightness field.

[0026] The technical effects and advantages of the present invention, which integrates content-aware and local backlight modulation for low-power liquid crystal display driving: This invention predetermines the backlight feasibility conditions for each pixel to complete brightness compensation based on the target brightness, the available transmittance range of the liquid crystal pixels, and the optical coupling response from the backlight partition to the liquid crystal pixels. This limits the reduction of backlight power consumption to the actual compensation capability of the liquid crystal. When a high-brightness pixel requires a higher backlight brightness to reach the target brightness within the maximum available transmittance range, the corresponding backlight driving amount will not be further reduced, thereby reducing the possibility of liquid crystal transmittance saturation, insufficient brightness in bright areas, and loss of grayscale details due to excessive backlight compression.

[0027] This invention establishes partition coupling relationships by utilizing the actual optical response formed by backlight partitions on the liquid crystal panel, and determines cross-boundary light leakage limiting conditions based on high-contrast boundaries in the content to be displayed. This limits the optical crosstalk generated by the bright partitions on the dark side regions during the backlight drive quantity calculation stage. Compared to methods that rely solely on the geometric adjacency of backlight partitions or perform halo correction after local dimming, this approach better reflects the spatial distribution characteristics formed by light diffusion and mixing in the actual backlight module. This helps to reduce black level rise in dark areas and halo phenomena at high-contrast boundaries while reducing backlight power consumption.

[0028] This invention converts the spatial brightness variation and inter-frame brightness variation of the content to be displayed into different content constraint information. Different brightness deviation requirements are applied to high-contrast contours, locally bright areas, and ordinary low-variety areas. This allows the limited backlight energy to prioritize areas with high requirements for maintaining the display structure, while allowing areas with less visual impact to optimize power consumption within a specified range. This improves the matching degree between backlight power consumption allocation and actual display content.

[0029] This invention further incorporates the limitation of backlight variation between consecutive display frames into the solution process of backlight driving quantity, so that the stability of backlight between frames, liquid crystal compensation capability, and spatial optical coupling relationship are simultaneously involved in the determination of the backlight state of the current frame. This avoids changing the actual backlight brightness by using independent time-domain filtering after obtaining the backlight driving result, thereby reducing local brightness jumps and flicker caused by rapid changes in backlight driving quantity, and maintaining the consistency between the backlight modulation state and the liquid crystal pixel compensation state.

[0030] When the target transmittance of the liquid crystal calculated based on the actual backlight brightness field exceeds the usable transmittance range, this invention can identify and compensate for mismatched pixels, and reverse locate the backlight zone that contributes to the brightness of the pixel based on the optical coupling response. By raising the driving lower limit of the associated backlight zone, the backlight state is re-solved, so that the compensation deficiency found on the liquid crystal side can be fed back to the backlight modulation process. This forms a closed-loop driving process of "backlight driving amount determination, actual backlight field reconstruction, liquid crystal transmittance verification, and backlight constraint correction", which improves the feasibility of low-power backlight state on real liquid crystal display modules. Attached Figure Description

[0031] Figure 1 This is a flowchart of a low-power driving method for liquid crystal displays that integrates content awareness and regional backlight modulation according to the present invention. Figure 2 This is a timing diagram showing the coordinated backlight modulation and liquid crystal pixel driving of the continuous display frames in this invention. Figure 3 This is a schematic diagram of the dynamic modulation of regional backlight in a continuous display scenario of a moving high-brightness target according to the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Figure 2 In this embodiment, the vertical synchronization signal is used as the unified time reference for continuous display frames. Frame, First Frame and the The content analysis, backlight drive quantity calculation, backlight data update, and liquid crystal pixel data update processes for each frame are recorded synchronously. For display areas with small content changes between frames, an upper limit for the inter-frame variation of the backlight zone drive quantity is set based on the corresponding content change amount, ensuring that the change in the backlight drive quantity of the current frame relative to the previous frame remains within an allowable range. When a scene change is detected, the inter-frame variation limit is relaxed, allowing the backlight drive state to keep up with the new display content. Finally, the backlight brightness field of the current frame is reconstructed based on the actual backlight drive vector used, and liquid crystal pixel drive data corresponding to this backlight state is generated, ensuring that the regional backlight modulation and liquid crystal transmittance compensation maintain a frame correspondence during continuous display. This avoids the mismatch between the backlight state and the liquid crystal compensation state that may be caused by independent temporal smoothing after the backlight drive quantity calculation is completed, while also reducing local brightness jumps in continuous low-change images.

[0034] Figure 3 In this process, a bright target with a predetermined size and target brightness is set in a low-brightness background, and the bright target is moved frame by frame in a predetermined direction during continuous display frames. When the bright target gradually moves from the corresponding area of ​​one backlight partition to the corresponding area of ​​another backlight partition, the driving amount of the relevant backlight partition is re-determined based on the target brightness distribution and partition optical response relationship of the current frame to be displayed. For cases where the content changes little between adjacent display frames, the inter-frame variation limit of the backlight partition driving amount is set according to the degree of inter-frame content change in the corresponding area, so that the driving amount of the backlight partition leaving the bright target gradually decreases, while the driving amount of the associated backlight partition in the direction of the bright target entering gradually increases, thereby making the backlight energy continuously migrate in space as the position of the bright target changes. Simultaneously, the actual backlight brightness field is reconstructed based on the backlight driving vector actually used in the current display frame, and the target transmittance and pixel driving data of the liquid crystal pixels corresponding to the high-brightness target are re-determined. This ensures that the dynamic modulation of the regional backlight and the brightness compensation of the liquid crystal pixels maintain the corresponding relationship of the current display frame, thereby reducing the local brightness jump that may be caused by the sudden change in backlight driving when the moving high-brightness target crosses the backlight partition, and keeping the display brightness of the moving target area within the allowable deviation range.

[0035] refer to Figures 1 to 3 Example 1: This example proposes a low-power driving method for liquid crystal displays that integrates content awareness and regional backlight modulation. The liquid crystal display module used in this embodiment includes a liquid crystal panel and a partitioned backlight module disposed on the back side of the liquid crystal panel. The backlight module includes multiple independently adjustable backlight partitions, and each backlight partition includes one or more LED light-emitting units. The backlight driving circuit can control the pulse width modulation duty cycle, driving current, or a combination of both for each backlight partition; the liquid crystal panel adjusts the liquid crystal transmittance at different pixel positions through a TFT pixel array.

[0036] In one possible implementation, the display panel can have a pixel resolution of 3840×2160, and the backlight module can be divided into 32×18 backlight zones, i.e., 576 independently controllable backlight zones. It should be noted that the above resolution and number of backlight zones are merely examples illustrating the technical principles of this embodiment; the present invention can also be applied to liquid crystal display modules with other pixel resolutions and other numbers of backlight zones.

[0037] This embodiment of a low-power driving method for liquid crystal displays that integrates content-aware and local backlight modulation includes the following steps: The target brightness data of the frame to be displayed is obtained, as well as the optical coupling response from the backlight partition to the sampling position of the liquid crystal pixel in the liquid crystal display module and the available transmittance range of the liquid crystal pixel. Content constraint information is determined based on the spatial brightness change and inter-frame brightness change of the target brightness data.

[0038] Based on the optical coupling response, target brightness data, and the available transmittance range of the liquid crystal pixels, the backlight feasibility conditions corresponding to each pixel achieving the target brightness within the liquid crystal compensation capability range are determined.

[0039] The partition coupling relationship is established based on the optical coupling relationship between different backlight partitions, and the light leakage limitation conditions corresponding to the high contrast boundary are determined according to the content constraint information.

[0040] While simultaneously satisfying the backlight feasibility condition and the light leakage limitation condition, the target driving quantity of each backlight zone is determined with the optimization direction of reducing backlight power consumption.

[0041] The actual backlight brightness field formed at the LCD panel is reconstructed based on the target driving amount and optical coupling response of each backlight zone. The transmittance of the LCD pixels is determined based on the target brightness data and the actual backlight brightness field. The LCD pixel driving data is generated based on the electro-optical response relationship of the LCD. The LCD pixel driving data and the backlight zone driving data are output according to the corresponding display frames.

[0042] This application does not determine the backlight intensity of a backlight zone solely based on the maximum or average grayscale of the image within that zone. Instead, it first considers the maximum effective transmittance achievable by the liquid crystal pixel before determining the backlight intensity. When the target pixel requires high brightness and the liquid crystal transmittance is already close to its maximum value, the backlight at the corresponding pixel location cannot be arbitrarily reduced, thus forming the minimum feasible condition for backlight driving.

[0043] Furthermore, this application considers that light generated by one backlight zone will propagate to the liquid crystal areas corresponding to other zones after passing through optical structures such as diffusers. Therefore, the coupling relationship between different backlight zones is established based on the actual optical response. For the high contrast boundary formed by the high brightness area and the low brightness area, a light leakage limit is set for the backlight zone that can cross the boundary and generate optical crosstalk. Thus, the liquid crystal compensation capability and the backlight optical crosstalk are jointly introduced into the backlight power consumption solution process.

[0044] The above process will be further explained below.

[0045] In this embodiment, the current frame to be displayed is first obtained from the video interface or the image processing module.

[0046] The frame to be displayed can be RGB image data. Since the input RGB grayscale is usually gamma-encoded, the grayscale value and the actual output brightness of the LCD panel are not strictly linearly related. Therefore, in this embodiment, the input image is first converted to a linear light domain for backlight calculation according to a preset electro-optical conversion relationship.

[0047] For example, input pixel position The RGB data is denoted as: .

[0048] The linear components are obtained based on the electro-optical conversion function corresponding to the display system: .

[0049] The pixel position is further determined based on the contribution relationship of the three color channels to the display brightness. Target brightness .

[0050] In practical applications, the above conversion relationship can be pre-calibrated and stored in a lookup table, and the display controller can directly obtain the target brightness by looking up the table based on the input grayscale, without having to perform complex real-time function calculations in each display frame.

[0051] In this embodiment, "target brightness" refers to the desired display brightness that the liquid crystal display module will produce at the corresponding position based on the content to be displayed, without implementing low-power backlight adjustment.

[0052] In this embodiment, after obtaining the target brightness data of the current frame, the spatial distribution and temporal changes of the target brightness are analyzed.

[0053] For a single pixel location or a pixel block composed of multiple pixels, obtain its own target brightness and the target brightness within a predetermined neighborhood, and determine the local brightness gradient based on the brightness difference between neighboring pixels.

[0054] For example, for pixel position The brightness changes in the horizontal and vertical directions are calculated separately, and the local brightness gradient is obtained based on the brightness changes in the two directions. .

[0055] At the same time, in terms of pixel position The maximum and minimum target brightness are obtained within a predetermined area centered on the target, and the local brightness dynamic range is determined based on the difference between the two. .

[0056] When a location has a large local brightness gradient or a large local brightness dynamic range, it indicates that the location is more likely to be located on the outline of an object, in a bright detail, or at a high contrast edge. Therefore, it is necessary to maintain a high degree of structural integrity during the backlight reduction process.

[0057] Further, obtain the target brightness at the same position in the current display frame and the previous display frame to obtain the inter-frame brightness residual: in, Indicates the currently displayed frame. This indicates the previous display frame.

[0058] Based on local brightness gradient Local brightness dynamic range and inter-frame brightness residual This determines the degree of spatial structure preservation and temporal variation corresponding to the pixel position.

[0059] In one implementation, the pixels involved in the backlight constraint calculation can be divided into brightness-preserving pixels and pixels that are allowed to compensate for deviations.

[0060] Among them, high-brightness details, high-contrast contours on both sides, and other locations where the display structure needs to be maintained are identified as brightness-maintaining pixels; areas with smooth brightness changes and insensitive to slight brightness changes are identified as allowable deviation compensation pixels.

[0061] Set brightness deviation tolerances for the two types of pixels mentioned above.

[0062] For example, the brightness deviation tolerance corresponding to the brightness-preserving pixel is denoted as... The brightness deviation tolerance corresponding to the allowed compensation deviation pixel is denoted as And satisfy: This allows the results of image content analysis to go beyond simply outputting a "salient region" label; they are further transformed into specific constraints that participate in the backlight solution.

[0063] In this embodiment, since the light generated by a backlight partition will form a light distribution with a certain spatial expansion range on the liquid crystal panel plane after passing through the diffuser plate, brightness enhancement film and other optical film materials, there is no strict one-to-one correspondence between the backlight partition and the liquid crystal pixel.

[0064] To accurately characterize the above relationship, this embodiment obtains in advance the brightness contribution of different backlight partitions to different liquid crystal pixel sampling positions.

[0065] Assume the backlight module includes Each backlight zone is selected from the LCD panel. A pixel sampling position used for backlight control calculations.

[0066] Each backlight zone is individually illuminated according to a predetermined driving amount. With other backlight zones turned off or kept in a preset reference state, the backlight brightness formed by the currently illuminated backlight zone at each pixel sampling position is measured.

[0067] For example, when the first When each backlight zone operates according to the unit normalized drive quantity, its first... The brightness contribution formed by each pixel sampling position is denoted as: The brightness contributions between all backlight zones and all pixel sampling locations are combined to form a zone optical response matrix: In actual products, the above matrix does not need to be remeasured after each power-on. It can be obtained and stored in non-volatile memory during the production, calibration or factory calibration stages of the LCD module.

[0068] For display modules with strong consistency in optical structure, a two-dimensional light distribution function corresponding to a backlight zone can be obtained first, and then spatial translation and discrete sampling can be performed according to the positional relationship of each backlight zone to obtain optical response data corresponding to different backlight zones.

[0069] When the current driving quantities of each backlight partition form a vector: At that time, the actual backlight brightness vector corresponding to the LCD panel can be determined based on the partition optical response matrix: in, The first in The term represents the first The actual backlight brightness received at each pixel sampling position.

[0070] It should be noted that when there is a significant nonlinearity between the light output and driving quantity of the backlight LED, the driving quantity can be converted into the actual light output quantity by first using the LED brightness and driving quantity calibration relationship, and then the brightness field reconstruction can be completed by using the partitioned optical response matrix.

[0071] In this embodiment, one of the key technical processes of this application is to determine the physical boundary by which the liquid crystal pixels can complete brightness compensation before reducing backlight power consumption.

[0072] For the For each liquid crystal pixel or pixel sampling position, let its target display brightness be: The maximum usable transmittance of a liquid crystal pixel is: Without considering allowable brightness deviation, the minimum incident backlight brightness that this pixel needs to achieve the target display brightness can be expressed as: When brightness deviation of the corresponding pixel is allowed At that time, the minimum backlight requirement can be determined by combining the target brightness and the allowable brightness deviation.

[0073] Further based on the partitioned optical response matrix Determined to be able to send to the first Each pixel provides an effective optical contribution to the backlight zone.

[0074] For example, when When the contribution is greater than the preset effective contribution threshold, the first... The backlight zone was determined to be the [number]th [zone]. Each pixel corresponds to an associated backlight zone.

[0075] Therefore, the actual backlight brightness obtained at this pixel location can be expressed as: And establish the following backlight constraint relationship for this pixel: The above-mentioned constraint relationships are established for each of the multiple liquid crystal pixels that need to participate in the constraint, thus forming the backlight feasible region corresponding to the current display frame.

[0076] In other words, although the optimization algorithm can continuously reduce the driving amount of different backlight zones, any candidate backlight driving combination must first meet the basic condition that the liquid crystal pixels can restore the target brightness through their own transmittance.

[0077] For example, if a high-brightness pixel targets a high-brightness display, and its maximum liquid crystal transmittance is close to the upper limit achievable by the liquid crystal material and driving voltage, then the minimum backlight requirement for that pixel is also correspondingly high. In this case, even if reducing the backlight zones in the vicinity can further reduce LED power consumption, as long as the reduction causes the pixel to be unable to restore the target brightness, the corresponding backlight state is excluded from the feasible backlight domain.

[0078] Therefore, this application does not discover the insufficient grayscale compensation of the liquid crystal only after the backlight has been reduced, but rather eliminates the backlight state that cannot be restored by utilizing the maximum available transmittance of the liquid crystal before determining the backlight driving amount.

[0079] In this embodiment, after obtaining the partition optical response matrix, the optical coupling relationship between the partitions is further determined based on the actual light distribution generated by different backlight partitions on the liquid crystal panel.

[0080] For the The first backlight zone and the first Each backlight zone can be used to calculate the degree of light distribution overlap based on the corresponding optical response vectors.

[0081] For example, the degree of coupling can be determined based on the overlapping region of the two response vectors, the degree of normalized correlation, or the number of pixels that both contribute effectively to brightness. .

[0082] when: At that time, it was believed that the first The backlight zone and the first There are optical coupling relationships between the various backlight zones that need to participate in the backlight control calculations. The threshold for determining coupling.

[0083] It should be noted that the “coupling partition” in this embodiment is not necessarily the same as the backlight partition that is physically adjacent to it.

[0084] For example, due to differences in diffuser thickness, LED emission angle, or optical film structure, a backlight zone may significantly contribute to the brightness of areas outside its geometrically adjacent zones. Therefore, this application determines the coupling relationship based on the actual measured or simulated optical response, rather than simply establishing the relationship between backlight zones according to "adjacent in the top, bottom, left, and right".

[0085] The high-contrast boundaries in the current image are then determined based on the aforementioned local brightness gradient.

[0086] For two regions that cross a high-contrast boundary, the side with higher target brightness is defined as the bright side, and the side with lower target brightness is defined as the dark side.

[0087] Select coupling relationships from the partition coupling relationships that have a significant optical contribution from the bright-side backlight partition to the dark-side pixels.

[0088] For dark side pixels If the set of backlight zones on the bright side is represented as The predicted light leakage brightness generated by the bright-side backlight partition can be expressed as: The corresponding light leakage upper limit is determined based on the target brightness of the dark-side pixel and the allowable brightness deviation. and establish: As a high-contrast boundary light leakage constraint.

[0089] For example, for highlighted text against a black background, traditional local dimming may increase the driving intensity of the corresponding backlight zone to meet the brightness requirements of the highlighted text, but the diffused light generated by the backlight zone will also enter the black area around the text.

[0090] This embodiment calculates the cross-boundary brightness contribution using the actual optical response matrix and sets a limit on the contribution before calculating the backlight drive amount, thereby actively avoiding backlight combinations that are prone to producing obvious halos during the optimization process.

[0091] In this embodiment, after determining the backlight feasibility conditions and light leakage limitation conditions, a backlight power consumption target is established.

[0092] Pre-measure the actual power of different backlight zones under different PWM duty cycles or different drive currents to obtain the first The relationship between the drive quantity and power of each backlight zone:

[0093] When all backlight zones use LEDs of the same specifications and basically the same driving circuits, a unified calibration function can be used; when there are differences in LED specifications, thermal state or driving characteristics in different areas, corresponding power functions can be established separately.

[0094] The total backlight power consumption of the current display frame can be expressed as: Therefore, in order to reduce To optimize the direction, a problem is solved by establishing the backlight drive quantity based on the current display frame.

[0095] The following conditions must be met simultaneously during the solution process: First, the backlight feasibility condition corresponding to the liquid crystal pixel; Second, the light leakage limitation condition corresponding to the dark side pixel of the high contrast boundary; Third, the allowable range of the driving amount of each backlight zone; Fourth, the inter-frame variation limitation under the following video display conditions.

[0096] This yields the candidate backlight driving vector.

[0097] For example, quadratic programming, linear programming, sequential convex optimization, or other numerical solution methods that can obtain solutions with lower power consumption under given constraints can be used.

[0098] This application does not take a specific mathematical solver as the core of the invention, as long as it can determine the backlight driving vector that meets the actual display requirements based on the above-mentioned backlight feasibility conditions, light leakage limitation conditions and power consumption targets.

[0099] When multiple backlight driving vectors that all satisfy the display constraints are obtained, the one with the lower predicted backlight power consumption is selected as the target backlight driving vector for the current display frame.

[0100] In this embodiment, for video display, if power minimization is performed completely independently for each frame, even if there are only minor changes in the images of adjacent frames, the optimal backlight driving amount corresponding to different partitions may change significantly.

[0101] Therefore, this embodiment further determines the inter-frame backlight change limit based on the content change status of the current frame and the previous frame.

[0102] For the Each backlight zone is used to determine the amount of content change in the corresponding image area based on the inter-frame brightness residual of multiple pixels within that zone. .

[0103] when: Furthermore, when significant brightness structure changes occur simultaneously in multiple regions, it can be determined that a scene switch has occurred, thereby expanding or temporarily canceling the inter-frame change restrictions for the corresponding partitions.

[0104] This avoids significant lag in backlight response caused by excessive time smoothing when video scenes change rapidly.

[0105] It should be noted that the inter-frame stabilization process in this application does not first obtain the "optimal backlight" and then perform low-pass filtering on the backlight PWM, but directly uses the above-mentioned inter-frame variation constraints as the backlight solution constraints.

[0106] Therefore, the final backlight driving quantity itself simultaneously satisfies the liquid crystal compensation capability, light leakage requirements, and inter-frame stability requirements, avoiding mismatch between the liquid crystal compensation grayscale and the actual backlight brightness after subsequent filtering changes the backlight state.

[0107] In this embodiment, after obtaining the target backlight driving vector, the actual backlight brightness field formed at the liquid crystal panel in the current frame is recalculated based on the partition optical response matrix: For the The actual backlight brightness is obtained from each liquid crystal pixel or pixel sampling position. .

[0108] Based on the target display brightness Determine the target transmittance that this pixel needs to achieve: Subsequently, the target pass rate Compare with the available transmittance range of the corresponding pixel.

[0109] when: This indicates that the current backlight state can be effectively compensated by the liquid crystal pixels.

[0110] Based on the pre-calibrated liquid crystal electro-optic response curve, the target transmittance is... This is converted into the corresponding TFT grayscale or driving voltage.

[0111] For example, a lookup table of "target transmittance and TFT grayscale" can be pre-established. The target transmittance is used to look up the table and perform necessary interpolation to obtain the grayscale data that the corresponding pixel needs to output.

[0112] In this embodiment, although the backlight driving amount has been limited by the backlight feasibility conditions, due to calibration errors, LED nonlinearity errors or discrete solution errors in the actual backlight response, after reconstructing the actual backlight brightness field, a small number of pixels may still have a target transmittance exceeding the maximum usable transmittance.

[0113] For example: At this point, the pixel is marked as a compensation mismatch pixel.

[0114] Unlike traditional solutions that directly truncate the pixel's grayscale to the maximum grayscale, this application further queries the backlight zones that effectively contribute to the brightness of the pixel based on the partitioned optical response matrix.

[0115] For example, the following: The corresponding backlight zone is determined as the associated backlight zone of the mismatched pixel.

[0116] The amount of incident backlight required to restore the mismatched pixel to a compensable state is then calculated, and the backlight drive lower limit of at least one associated backlight zone is raised accordingly.

[0117] Since increasing the driving amount of a backlight partition may affect other surrounding pixels through optical diffusion, the process does not end after modifying only the backlight partition. Instead, the aforementioned backlight solution process is called back to recalculate the relevant backlight partitions that have optical coupling with it.

[0118] Then, the following steps are performed again: backlight drive quantity determination; actual backlight brightness field reconstruction; target transmittance calculation; compensation capability assessment.

[0119] Continue until there are no more mismatched pixels exceeding the allowable brightness deviation, or until the preset maximum number of iterations is reached.

[0120] This results in a closed-loop processing procedure: backlight solution, actual light field reconstruction, liquid crystal compensation verification, mismatched pixel location, associated backlight constraint write-back, and re-solution.

[0121] This processing method allows for further feedback to the backlight layer to correct local compensation deficiencies caused by model errors or discrete solutions, rather than relying entirely on the liquid crystal grayscale side to undertake the compensation task.

[0122] In this embodiment, after obtaining the final target backlight driving vector, the normalized driving quantities of different backlight zones are converted into control data that the backlight driving circuit can actually execute.

[0123] For example, when using PWM dimming, the driving quantity is converted into the PWM duty cycle of the corresponding backlight zone; when using current dimming, the driving quantity is converted into the corresponding LED driving current; when using PWM and driving current combined adjustment, the corresponding control parameters are determined according to the pre-established mapping relationship between LED brightness, PWM, and current.

[0124] At the same time, the target transmittance of all liquid crystal pixels is determined based on the final actual backlight brightness field, and TFT grayscale data is obtained based on the liquid crystal electro-optic response relationship.

[0125] Both the backlight driving data and the TFT grayscale data are set with the corresponding identifier of the current display frame, and are written into the backlight driving circuit and the LCD panel driving circuit respectively according to the predetermined scanning sequence of the display system.

[0126] In one implementation, the backlight driver cache can be updated first, and then the new backlight control data and the corresponding liquid crystal pixel data can be made effective simultaneously in the next vertical synchronization cycle to avoid mismatch between the liquid crystal pixel data and the backlight state of different display frames.

[0127] Thus, the actual LCD display brightness is determined by the final backlight brightness: Corresponding to the actual transmittance of the liquid crystal: They jointly decide to make them correspond to the same target display frame.

[0128] For example, the above low-power driving process is further illustrated by taking a continuous video frame with a bright target and a dark background.

[0129] The frame to be displayed currently includes a highlighted object located in the center of the screen and a low-brightness background area surrounding the highlighted object.

[0130] First, the target brightness of each pixel is obtained based on the frame to be displayed. Areas near the boundaries of highlighted objects, due to their large local brightness gradients, are identified as high-contrast regions that require special attention, and pixels on either side of these boundaries are given a smaller brightness deviation tolerance. Background areas far from the highlighted objects and with gradual brightness changes are given a relatively larger brightness deviation tolerance.

[0131] Then, based on the pre-calibrated partition optical response matrix, multiple backlight partitions corresponding to the highlighted object are determined.

[0132] Assuming the highlighted object is mainly located in the area corresponding to backlight zone A, it can be determined from the optical response matrix that a portion of the light generated by backlight zone A also propagates to the pixel position corresponding to the adjacent dark background.

[0133] If the driving amount of backlight zone A is increased simply according to the maximum gray level of the highlighted object, its diffused light may significantly increase the actual backlight brightness of the background area.

[0134] In this embodiment, the predicted light leakage brightness of the backlight partition A for the dark side pixels is calculated, and the predicted light leakage brightness shall not exceed the upper limit of the light leakage corresponding to the dark side pixels.

[0135] At the same time, for pixels in a high-brightness object, the minimum backlight requirement is calculated based on its target brightness and maximum available liquid crystal transmittance.

[0136] If the backlight continues to decrease, the corresponding liquid crystal pixels need to reach a state that exceeds the maximum usable transmittance. In this case, the backlight combination does not belong to the backlight feasible region of the current frame.

[0137] Therefore, the backlight solver actually determines a backlight combination that can both ensure that the brightness of the high-brightness object can still be restored by the liquid crystal transmittance, limit the light leakage of the high-brightness backlight into the dark background, and have relatively low LED power consumption.

[0138] In subsequent consecutive display frames, if the highlighted target only moves within a small range, the corresponding backlight zone is limited by the inter-frame change to avoid rapid changes in backlight intensity; if the entire screen switches to a new scene, the above restrictions are relaxed, allowing the backlight to respond quickly to the new screen content.

[0139] Thus, joint control of content status, liquid crystal compensation capability, backlight optical crosstalk, and backlight power consumption can be achieved under continuous video conditions.

[0140] Example 3 This embodiment of the present invention provides a low-power driving system for liquid crystal displays that integrates content awareness and regional backlight modulation, specifically including an image processing unit, a backlight control unit, a liquid crystal compensation unit, and a storage unit. The storage unit stores at least: the optical response matrix of the backlight partition to the sampling position of the liquid crystal pixel; the calibration relationship between the backlight partition driving quantity and the LED light output; the correspondence between the backlight partition driving quantity and the electrical power; the electro-optical response relationship between the liquid crystal grayscale and the liquid crystal transmittance; and the available transmittance range corresponding to the liquid crystal pixel or liquid crystal panel.

[0141] The image processing unit receives the frame to be displayed and converts the image data into target brightness data for backlight modulation.

[0142] Subsequently, content constraint information is determined based on the spatial gradient of the target brightness, the local dynamic range, and the brightness change between the current frame and the previous frame.

[0143] The backlight control unit reads the partition optical response matrix and available transmittance data from the storage unit, calculates the minimum backlight requirement for each pixel based on the target brightness, and forms backlight feasibility conditions.

[0144] Meanwhile, the backlight control unit determines the optical coupling relationship between different backlight zones based on the zone optical response matrix, determines the high contrast boundary based on the content constraint information, and establishes light leakage constraint conditions based on the predicted brightness contribution of the high-brightness backlight zone to the dark side pixels.

[0145] Under the conditions of backlight feasibility, light leakage limitation, and inter-frame variation limitation, the backlight control unit performs power consumption optimization to obtain the target backlight driving vector.

[0146] The liquid crystal compensation unit calculates the actual backlight brightness field based on the target backlight driving vector and the partition optical response matrix, then determines the target transmittance of the corresponding liquid crystal pixel based on the target brightness of the frame to be displayed, and generates the corresponding TFT grayscale data based on the liquid crystal electro-optic response relationship.

[0147] If the target transmittance is found to exceed the maximum usable transmittance, the liquid crystal compensation unit will identify the corresponding pixel as a mismatched pixel and feed the mismatched pixel information back to the backlight control unit.

[0148] The backlight control unit determines the associated backlight partition of the corresponding mismatched pixel based on the partition optical response matrix, raises the driving lower limit of the associated backlight partition and re-solves the problem so that the backlight control and liquid crystal compensation form a closed loop.

[0149] Finally, backlight zone driving data is output to the backlight driving circuit, and corresponding TFT grayscale data is output to the LCD panel driving circuit.

[0150] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0151] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0152] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0153] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0154] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0155] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-power driving method for liquid crystal displays that integrates content-aware and local backlight modulation, characterized in that, include: Acquire the target brightness data of the frame to be displayed, and obtain the optical coupling response from the backlight partition to the sampling position of the liquid crystal pixel in the liquid crystal display module and the available transmittance range of the liquid crystal pixel; Content constraint information is determined based on the spatial brightness variation and inter-frame brightness variation of the target brightness data; Based on the optical coupling response, target brightness data, and available transmittance range, determine the backlight feasibility conditions for each pixel to achieve the target brightness within the liquid crystal compensation capability range; A partition coupling relationship is established based on the optical coupling relationship between the backlight partitions, and the light leakage limitation condition corresponding to the high contrast boundary is determined according to the content constraint information. Under the condition that both the backlight feasibility condition and the light leakage limitation condition are met, the driving amount of each backlight zone is determined with the goal of reducing backlight power consumption. The actual backlight brightness field at the liquid crystal panel is reconstructed based on the driving amount of each backlight zone and the optical coupling response. The transmittance of the liquid crystal pixels is determined based on the target brightness data and the actual backlight brightness field. Pixel driving data is generated based on the liquid crystal electro-optic response relationship, and backlight zone driving data is output synchronously.

2. The low-power driving method for liquid crystal displays according to claim 1, characterized in that, The content constraint information to be determined includes: Perform linear optical domain transformation on the target brightness data, and calculate the local brightness gradient, local brightness dynamic range, and brightness residual between the current frame and the previous frame for each pixel or pixel block. The degree of spatial structure preservation is determined based on the local brightness gradient and the local brightness dynamic range, and the degree of time change is determined based on the brightness residual. Based on the degree of spatial structure preservation and the degree of time change, the pixels are divided into at least brightness-preserving pixels and pixels with allowable compensation deviation, and different brightness deviation tolerances are set for each. Among them, the brightness-preserving pixels on both sides of the high contrast contour and in the local bright area have a brightness deviation tolerance that is smaller than that of the pixels with allowable compensation deviation.

3. The low-power driving method for liquid crystal displays according to claim 2, characterized in that, The optical coupling response is characterized by the partition optical response matrix of the backlight module. The matrix elements in the partition optical response matrix represent the brightness contribution of a backlight partition to the sampling position of the corresponding liquid crystal pixel under a predetermined driving amount. The partitioned optical response matrix is ​​obtained by lighting up the backlight partition by partition and obtaining the brightness response of multiple liquid crystal pixel sampling positions, or by discretizing the light distribution function measured partition by partition. During the display driving process, the spatial backlight brightness field at the liquid crystal panel is calculated based on the mapping relationship between the driving amount of each backlight zone and the optical response matrix of the zone.

4. The low-power driving method for liquid crystal displays according to claim 3, characterized in that, The backlight feasibility conditions are determined in the following manner: The minimum incident backlight brightness required for a pixel is determined based on the maximum usable transmittance of the liquid crystal pixel and the target brightness of the corresponding pixel. Based on the partition optical response matrix, one or more associated backlight partitions that can provide incident backlight to the pixel are determined, and the sum of the brightness contributions of each associated backlight partition is limited to no less than the minimum incident backlight brightness minus the allowed brightness deviation of the pixel. The aforementioned constraints corresponding to each pixel together form the backlight feasible region of the current frame to be displayed, so that the determined backlight partition driving amount is located within the backlight feasible region.

5. The low-power driving method for liquid crystal displays according to claim 4, characterized in that, Establishing the partition coupling relationship includes: The degree of light distribution overlap between any two backlight zones on the LCD panel is calculated based on the partition optical response matrix. When the degree of light distribution overlap reaches the preset coupling condition, a coupling relationship is established between the corresponding two backlight zones. Determine the coupling relationship across the high contrast boundary and calculate the predicted light leakage brightness of the backlight partition located on the bright side of the high contrast boundary to the dark side pixels. The upper limit of light leakage is set according to the target brightness of the dark side pixel and its brightness deviation tolerance, so that the predicted light leakage brightness does not exceed the upper limit of light leakage.

6. The low-power driving method for liquid crystal displays according to claim 5, characterized in that, Determining the drive parameters for each backlight zone includes: The backlight power consumption target is constructed based on the calibration relationship between the driving quantity of each backlight zone and the corresponding LED power. With the goal of minimizing backlight power consumption as the optimization direction, and with at least the backlight feasibility conditions corresponding to the brightness-maintaining pixels, the brightness deviation tolerance corresponding to the allowed compensation deviation pixels, and the light leakage limitation conditions corresponding to the high contrast boundary as constraints, the candidate backlight driving vector of the current frame to be displayed is obtained. When there are multiple candidate backlight driving vectors that meet the constraints, the candidate backlight driving vector with the lower backlight power consumption is selected as the target backlight driving vector.

7. The low-power driving method for liquid crystal displays according to claim 6, characterized in that, Also includes: The content change amount of each backlight partition is determined based on the brightness residual difference between the current frame and the previous frame, and the inter-frame change limit of the backlight drive amount is set based on the content change amount. For backlight zones where the content change is less than the first change threshold, the change in the current frame drive amount relative to the previous frame drive amount is limited. For backlight zones where the amount of content change exceeds the second change threshold and is determined to be a scene switch, the change range limit is expanded or removed. The inter-frame variation constraint is incorporated into the solution process of the backlight drive quantity, so that the backlight variation in the time-continuous frame is constrained by the content change state.

8. The low-power driving method for liquid crystal displays according to claim 7, characterized in that, Determining the transmittance of liquid crystal pixels based on the actual backlight brightness field includes: The target transmittance is determined by the ratio of the target brightness to the actual backlight brightness at the corresponding pixel position; Compare the target transmittance with the available transmittance range of the corresponding liquid crystal pixel; When the target transmittance exceeds the maximum available transmittance, the pixel is marked as a compensated mismatch pixel, and the associated backlight zone that contributes to the brightness of the compensated mismatch pixel is determined according to the partition optical response matrix. Raise the lower limit of the backlight drive of at least one associated backlight zone, and redetermine the drive amount of the backlight zone that has an optical coupling relationship with the associated backlight zone, until the compensated mismatch pixel meets the brightness deviation tolerance or reaches the preset iteration termination condition.

9. The low-power driving method for liquid crystal displays according to claim 8, characterized in that, The backlight zone driving data includes the pulse width modulation duty cycle and / or driving current amplitude of each backlight zone, and the pixel driving data includes TFT grayscale data obtained by reverse calculation based on the liquid crystal electro-optic response curve. According to the same display frame correspondence, the target backlight driving vector is written into the backlight driving circuit, and the corresponding TFT grayscale data is written into the liquid crystal panel driving circuit, so that the liquid crystal transmittance corresponding to the TFT grayscale data acts on the actual backlight brightness field formed according to the target backlight driving vector.

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