Liquid crystal display device and backlight brightness adjusting method of liquid crystal display device

Abstract

The embodiment of the invention belongs to the technology of display equipment, and provides liquid crystal display equipment and a backlight brightness adjusting method of the liquid crystal display equipment, a processor obtains APLs corresponding to images in a plurality of backlight partitions, and determines PWM duty ratio upper limit values and DC current upper limit values corresponding to the plurality of backlight partitions according to the APLs corresponding to the plurality of backlight partitions. Target backlight brightness corresponding to the backlight partitions is determined according to the APLs corresponding to the backlight partitions and a pre-stored mapping relation between the APLs and the backlight brightness, and the APLs and the backlight brightness in the mapping relation are in a non-linear relation. And according to the target backlight brightness corresponding to the plurality of backlight partitions and the corresponding PWM duty ratio upper limit value, target PWM duty ratio values corresponding to the plurality of backlight partitions are determined, and the backlight module adjusts the backlight brightness of the corresponding backlight partitions according to the target PWM duty ratio values and the DC current upper limit value. According to the invention, the accuracy of backlight brightness adjustment of the medium and high brightness areas is improved.

Description

Technical Field

[0001] The present invention relates to liquid crystal display technology, and more specifically, to a liquid crystal display device and a method for adjusting the backlight brightness of the liquid crystal display device. Background Art

[0002] With the rapid development of display technology, users have also put forward higher requirements for liquid crystal display devices. The brighter and clearer the image displayed by the liquid crystal display device, the better the user experience.

[0003] In the related art, when adjusting the backlight brightness of an image displayed on a liquid crystal display device, it is usually adjusted according to a preset Peaking curve, and according to the direct current (DC) current value and pulse width modulation (PWM) duty cycle value corresponding to the backlight brightness in the Peaking curve.

[0004] However, the above method is more suitable for adjusting the backlight brightness of low-brightness areas in the display screen, and is not accurate enough for adjusting the backlight brightness of medium and high-brightness areas. Summary of the Invention

[0005] The embodiments of the present application provide a liquid crystal display device and a method for adjusting the backlight brightness of the liquid crystal display device, which can be used to solve the problem of inaccurate backlight brightness adjustment in medium and high brightness areas in the related art.

[0006] In a first aspect, an embodiment of the present application provides a liquid crystal display device, comprising:

[0007] A liquid crystal display screen, the liquid crystal display screen being divided into a plurality of backlight partitions, the liquid crystal display screen being configured to: display an image;

[0008] a backlight module connected to the liquid crystal display screen, the backlight module being configured to: emit backlight, the backlight being used to adjust the backlight brightness of the displayed image;

[0009] A processor connected to the liquid crystal display and the backlight module respectively, wherein the processor is configured to:

[0010] Acquire an average picture level APL corresponding to the images in the plurality of backlight subareas;

[0011] determining, according to average picture levels (APLs) corresponding to the images in the plurality of backlight partitions, upper limits of pulse width modulation (PWM) duty cycles and upper limits of DC currents corresponding to the images in the plurality of backlight partitions;

[0012] determining target backlight brightness corresponding to the plurality of backlight subareas according to average picture levels (APLs) corresponding to the plurality of backlight subareas and a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness, wherein the mapping relationship has a nonlinear relationship between the average picture level (APL) and the backlight brightness;

[0013] Determining target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to target backlight brightnesses and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions;

[0014] The backlight module is further configured to adjust the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions.

[0015] In this application, the processor determines the target backlight brightness corresponding to each backlight partition based on the APL corresponding to each backlight partition from a pre-stored mapping relationship between the average image level APL and the backlight brightness. Furthermore, the processor determines the target PWM duty cycle value for adjusting the corresponding backlight partition based on the obtained PWM duty cycle upper limit and the target backlight brightness. Furthermore, the processor adjusts the backlight brightness of the corresponding backlight partition based on the target PWM duty cycle value and the obtained DC current upper limit. In the mapping relationship in this application, the relationship between APL and backlight brightness is nonlinear, meaning that the backlight brightness corresponding to the APL mapping of the mid- and high-brightness areas is adjusted, thereby improving the accuracy of backlight brightness adjustment in the mid- and high-brightness areas.

[0016] In some embodiments of the present application, the processor is further configured to:

[0017] Acquire an original mapping relationship between an average picture level (APL) and backlight brightness, wherein the original mapping relationship is a linear relationship between the average picture level (APL) and backlight brightness;

[0018] According to a preset target average picture level APL, the linear relationship in the original mapping relationship is adjusted to obtain an adjusted mapping relationship between the average picture level APL and the backlight brightness, wherein the average picture level APL and the backlight brightness in the adjusted mapping relationship are in a nonlinear relationship;

[0019] The mapping relationship between the adjusted average picture level APL and the backlight brightness is stored.

[0020] In this application, the processor adjusts the original mapping relationship between the average image level APL and the backlight brightness from the original linear relationship to a nonlinear relationship, and obtains the adjusted mapping relationship between the average image level APL and the backlight brightness, so that the target backlight brightness can be determined more accurately based on the adjusted mapping relationship between the average image level APL and the backlight brightness.

[0021] In some embodiments of the present application, when the processor is configured to adjust the linear relationship in the original mapping relationship according to a preset target average picture level APL to obtain an adjusted mapping relationship between the average picture level APL and the backlight brightness, the process specifically includes:

[0022] Determining an upper limit value of the backlight brightness according to the backlight brightness in the original mapping relationship;

[0023] According to the preset target average picture level APL, the backlight brightness corresponding to the APL exceeding the preset target average picture level APL is adjusted to the upper limit value of the backlight brightness to obtain a mapping relationship between the adjusted average picture level APL and the backlight brightness.

[0024] In this application, the processor adjusts the backlight brightness corresponding to the APL that exceeds the preset target average image level APL to the upper limit value of the backlight brightness. By increasing the backlight brightness value of the APL that exceeds the preset target average image level APL, the accuracy of the backlight brightness adjustment in the medium and high-brightness areas is improved.

[0025] In some embodiments of the present application, when the processor is configured to obtain an average picture level APL corresponding to the images in the plurality of backlight subareas, the processor specifically includes:

[0026] Obtaining the number of pixels corresponding to the images in the plurality of backlight subareas and the grayscale brightness values ​​of the pixels;

[0027] An average value calculation is performed according to the number of pixels and the grayscale brightness values ​​of the pixels to obtain an average picture level APL corresponding to the images in the multiple backlight subareas.

[0028] In this application, the processor obtains the number of pixels and grayscale brightness values ​​of the image in each backlight partition, and determines the average image level APL corresponding to each backlight partition based on the number of pixels and grayscale brightness values, thereby improving the accuracy and convenience of obtaining the average image level APL corresponding to each backlight partition.

[0029] In some embodiments of the present application, when the processor is configured to determine, based on the average picture levels APL corresponding to the images in the multiple backlight partitions, the pulse width modulation (PWM) duty cycle upper limit and the DC current upper limit corresponding to the images in the multiple backlight partitions, the process specifically includes:

[0030] For at least one backlight partition, determining, based on an average picture level (APL) corresponding to an image in the backlight partition, a pulse width modulation (PWM) duty cycle value and a DC current value corresponding to the image when the image reaches a preset upper power limit of a power supply;

[0031] Determine the pulse width modulation (PWM) duty cycle value corresponding to when the preset upper limit power of the power supply is reached as the pulse width modulation (PWM) duty cycle upper limit value of the backlight partition;

[0032] The DC current value corresponding to when the preset upper limit power of the power supply is reached is determined as the DC current upper limit value of the backlight partition.

[0033] In the present application, the processor determines the pulse width modulation (PWM) duty cycle value corresponding to the image in each backlight partition when the power reaches the preset upper limit power of the power supply as the PWM duty cycle upper limit value based on the average picture level (APL) corresponding to the image in each backlight partition, and determines the DC current value corresponding to the image in each backlight partition when the power reaches the preset upper limit power of the power supply as the DC current upper limit value, thereby improving the accuracy of the obtained PWM duty cycle upper limit value and DC current upper limit value.

[0034] In some embodiments of the present application, when the processor is configured to determine the target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to the target backlight brightness and the corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions, the process specifically includes:

[0035] determining adjustment coefficients corresponding to the plurality of backlight partitions according to target backlight brightness corresponding to the plurality of backlight partitions and an upper limit value of backlight brightness in the pre-stored mapping relationship between average picture level APL and backlight brightness;

[0036] Target PWM duty cycle values ​​corresponding to the multiple backlight partitions are determined according to the adjustment coefficients and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions.

[0037] In the present application, the processor determines the adjustment coefficient corresponding to each backlight partition based on the target backlight brightness of each backlight partition and the upper limit value of the backlight brightness in the pre-stored mapping relationship between the average image level APL and the backlight brightness, and then determines the target PWM duty cycle value of the corresponding backlight partition based on the adjustment coefficient corresponding to each backlight partition and the corresponding PWM duty cycle upper limit value, thereby improving the accuracy of the determined target PWM duty cycle value and facilitating the processor to subsequently adjust the backlight brightness of the image based on the target PWM duty cycle value.

[0038] In some embodiments of the present application, when the backlight module is configured to adjust the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions, the method specifically includes:

[0039] generating corresponding PWM control signals according to target PWM duty cycle values ​​corresponding to the plurality of backlight partitions;

[0040] generating corresponding DC current control signals according to the DC current upper limit values ​​corresponding to the plurality of backlight partitions;

[0041] The backlight brightness of the corresponding backlight partition is adjusted according to the PWM control signal and the DC current control signal.

[0042] In this application, the processor generates corresponding control signals based on the target PWM duty cycle value and DC current upper limit value corresponding to each backlight partition, and adjusts the backlight brightness of the image of the corresponding backlight partition according to the generated control signal, thereby improving the feasibility and efficiency of the backlight brightness adjustment of the image.

[0043] In a second aspect, the present application provides a method for adjusting the backlight brightness of a liquid crystal display device, the method comprising:

[0044] The LCD screen displays images;

[0045] The backlight module emits backlight, and the backlight is used to adjust the backlight brightness of the displayed image;

[0046] The processor obtains an average picture level APL corresponding to the images in the plurality of backlight subareas;

[0047] The processor determines, according to an average picture level (APL) corresponding to the images in the plurality of backlight partitions, a pulse width modulation (PWM) duty cycle upper limit and a DC current upper limit corresponding to the images in the plurality of backlight partitions;

[0048] The processor determines target backlight brightness corresponding to the plurality of backlight subareas based on average picture levels (APLs) corresponding to the plurality of backlight subareas and a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness, wherein the mapping relationship has a nonlinear relationship between the average picture level (APL) and the backlight brightness;

[0049] The processor determines target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to target backlight brightness and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions;

[0050] The backlight module adjusts the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions.

[0051] In the present application, the processor determines the target backlight brightness corresponding to each backlight partition based on the APL corresponding to each backlight partition and from a pre-stored mapping relationship between the average image level APL and the backlight brightness. Furthermore, the processor determines the target PWM duty cycle value for adjusting the corresponding backlight partition based on the obtained PWM duty cycle upper limit and the target backlight brightness. Furthermore, the processor adjusts the backlight brightness of the corresponding backlight partition based on the target PWM duty cycle value and the obtained DC current upper limit. The mapping relationship in the present application is a nonlinear relationship between APL and backlight brightness, meaning that the backlight brightness corresponding to the APL mapping of the mid- and high-brightness areas is adjusted, thereby improving the accuracy of backlight brightness adjustment in the mid- and high-brightness areas.

[0052] In a third aspect, an embodiment of the present application provides a computer-readable storage medium having computer execution instructions stored thereon. When the computer execution instructions are executed by a processor, the backlight brightness adjustment method of the liquid crystal display device described in the second aspect is implemented.

[0053] The present application provides a computer-readable storage medium to provide storage conditions for executing a backlight brightness adjustment method for a liquid crystal display device.

[0054] In a fourth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the backlight brightness adjustment method of the liquid crystal display device described in the second aspect.

[0055] The computer program product provided in this application provides an operating program for executing a backlight brightness adjustment method for a liquid crystal display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the implementation methods in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0057] Figure 1 A schematic diagram of the hardware configuration of a liquid crystal display device provided in some embodiments of the present application;

[0058] Figure 2 A schematic diagram of an exemplary dimming structure provided in some embodiments of the present application;

[0059] Figure 3A A Peaking curve diagram provided for some embodiments of the present application;

[0060] Figure 3BAnother Peaking curve schematic diagram provided for some embodiments of the present application;

[0061] Figure 4 A schematic flow chart of a method for adjusting backlight brightness of a liquid crystal display device provided in some embodiments of the present application;

[0062] Figure 5A A schematic diagram of backlight partitioning provided in some embodiments of the present application;

[0063] Figure 5B A schematic diagram of another backlight partition provided in some embodiments of the present application;

[0064] Figure 6 A flowchart of a method for obtaining a pre-stored mapping relationship between an average picture level (APL) and backlight brightness provided in an embodiment of the present application;

[0065] Figure 7 A flowchart of a method for obtaining a mapping relationship between an adjusted average picture level (APL) and backlight brightness provided in some embodiments of the present application;

[0066] Figure 8 A flowchart of a method for determining a target PWM duty cycle value corresponding to a backlight partition provided in some embodiments of the present application. DETAILED DESCRIPTION

[0067] In order to make the purpose, implementation mode and advantages of the present application clearer, the exemplary implementation mode of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0068] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0069] In addition, the terms "comprises" and "comprising" and any variations thereof are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to those components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0070] With the rapid development of display technology, users' requirements for LCD devices are becoming increasingly higher. Backlighting is a common technology in LCD devices, used to provide light for the display screen, making the image visible in dark environments. The brightness of the backlight affects the clarity of the image displayed on the display. By adjusting the backlight brightness of the image, bright areas in the displayed image can be brightened and dark areas can be darkened, making the image clearer and less bleached.

[0071] In the application scenarios of the present application, the liquid crystal display device can have various implementation forms, for example, it can be a television, a smart TV, a laser projection device, a monitor, an electronic bulletin board, an electronic table, etc.

[0072] It is understood that the liquid crystal display devices proposed in this application include but are not limited to the above devices, and the above devices are not intended to limit this application. In addition, this application does not limit the type, size, specifications, etc. of the specific liquid crystal display device.

[0073] In order to facilitate understanding of the liquid crystal display device of the present application, the structure of the liquid crystal display device is described below. Figure 1 A schematic diagram of the hardware configuration of a liquid crystal display device provided in some embodiments of the present application is shown in FIG. Figure 1 As shown:

[0074] The liquid crystal display device includes: a liquid crystal display screen 101 , a backlight module 102 , a processor 103 , a driver board 104 , a power board 105 , a high-voltage board 106 , a key board 107 and an audio and video signal input interface 108 .

[0075] The LCD screen 101 includes a display screen component for presenting images, a driving component for driving image display, a component for receiving image signals, and displaying video content, image content, and a menu control interface, as well as a user control UI interface.

[0076] The backlight module 102 includes a light source, a light-transmitting module, a reflective module and other components, and is used to provide backlight for the liquid crystal display screen 101 so as to display clear images.

[0077] The light source is the most fundamental component of the backlight module, and can be, for example, an LED. The light-transmitting module typically consists of a uniform optical guide or light-transmitting film to ensure backlight uniformity. The reflective module reflects light from the light source, allowing it to better pass through the LCD 101. Other components, such as optical sheets, adjust and control the color and brightness of the backlight to achieve optimal image display.

[0078] The processor 103 may include at least one of a video processor 103, an audio processor 103, a graphics processing unit 103 (GPU), random access memory (RAM), read-only memory (ROM), first to nth interfaces for input / output, and a communication bus. The processor 103 may control the operation of the liquid crystal display device and respond to various user operations through various stored software control programs.

[0079] The driver board BCON is used to control the display of the LCD screen 101. It obtains audio and video signals from the audio and video signal input interface 108, and processes the audio and video input signals and sends them to the LCD screen 101 in a specific manner, so that the LCD screen 101 can display images. The driver panel 104 can usually include components such as driver chips and logic circuits.

[0080] The high-voltage board 106 is an important component of the liquid crystal display device. It is a board that carries high-voltage power. In the liquid crystal display 101, the function of the high-voltage board is to convert the low-voltage power supply into a high-voltage power supply to provide sufficient power to drive the display of the liquid crystal display, that is, to light up the backlight source in the liquid crystal display device so that the liquid crystal display 101 can display a complete image under the illumination of the backlight source.

[0081] The power board 105 is used to provide power to components in the liquid crystal display device so that each component can operate normally.

[0082] The keypad 107 is used to receive key signals from the user and send the signals to the processor 103 and the like. The keypad 107 generally includes components such as key switches and interface lines.

[0083] The schematic diagram of backlight adjustment by the backlight module 102 can be as follows: Figure 2 As shown, Figure 2 A schematic diagram of an exemplary dimming structure provided for some embodiments of the present application.

[0084] After the processor obtains the grayscale brightness of the image through the audio and video signal input interface 201, it transmits the grayscale brightness to the backlight control unit circuit 202 in the backlight module through the SPI interface communication according to the preset algorithm. The backlight control unit circuit 202 controls the MINI LED lamp tube 204 to emit backlight through the MINI LED drive circuit 203. The backlight is used to adjust the brightness of the image displayed on the liquid crystal display 205.

[0085] In the related art, when the backlight brightness of the image is adjusted by the above-mentioned liquid crystal display device, it is usually adjusted based on the Peaking curve, and the Peaking adjustment usually includes DC dimming and PWM dimming. Among them, DC dimming uses a dimmer to adjust the current to control the brightness of the light. In DC dimming, the current is proportional to the brightness of the light. The larger the current, the brighter the light, and the smaller the current, the darker the light. PWM dimming is a technology that controls the output voltage or current by adjusting the duty cycle. Specifically, PWM adjusts the output voltage or current by modulating the time ratio of the high level (or forward current) and low level (or reverse current) of the periodically changing voltage or current.

[0086] During adjustment, the adjustment is performed according to the DC current value and the PWM duty cycle value corresponding to the backlight brightness in the Peaking curve. Figure 3A A Peaking curve diagram provided in some embodiments of the present application is shown below. Figure 3B Another Peaking curve diagram provided in some embodiments of the present application is as follows: Figure 3A and Figure 3B As shown, in the window corresponding to the average pixel luminance (APL), the backlight brightness to be adjusted can be determined according to the Peaking curve, and the DC current value and the PWM duty cycle value are adjusted according to the backlight brightness until the backlight brightness is reached.

[0087] However, the above method is limited by the power supply and is more suitable for adjusting the backlight brightness of low-brightness areas in the display screen to improve the brightness of low-brightness areas. Brightness smoothing processing is required for medium and high-brightness areas, resulting in inaccurate backlight brightness adjustment for medium and high-brightness areas.

[0088] Therefore, in response to the above technical problems in the prior art, the inventors discovered during the research process that a mapping relationship between the average image level APL and the backlight brightness is established, in which the APL corresponds to the backlight brightness one-to-one, and the backlight brightness corresponding to multiple APLs in the mapping relationship that are higher than the preset target APL (higher than the preset target APL is the APL corresponding to the medium and high brightness areas) is adjusted to the upper limit of the backlight brightness. After the APL in the backlight partition is determined, the PWM duty cycle upper limit and the DC current upper limit are determined according to the APL, and the target backlight brightness corresponding to the APL is determined according to the APL and the established mapping relationship. The target PWM duty cycle value for backlight adjustment of the displayed image is determined according to the target backlight brightness and the PWM duty cycle upper limit, and then the backlight brightness of the image in the corresponding backlight partition is adjusted based on the target PWM duty cycle value and the DC current upper limit, thereby improving the backlight brightness of the image in the medium and high brightness areas. Based on this, the present application proposes a liquid crystal display device and a backlight brightness adjustment method for a liquid crystal display device.

[0089] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0090] Figure 4 A flow chart of a method for adjusting the backlight brightness of a liquid crystal display device provided in some embodiments of the present application is shown as follows: Figure 4 As shown, the method may include the following steps:

[0091] S401. The LCD screen displays an image.

[0092] In this embodiment, the liquid crystal display screen 101 is divided into a plurality of backlight subareas 01. Figure 5A A schematic diagram of backlight partitioning provided in some embodiments of the present application, such as Figure 5A As shown, the liquid crystal display screen 101 can be divided into 4 rows and 6 columns, with a total of 24 backlight sub-areas 02, and the area of ​​each backlight sub-area is the same. Figure 5B A schematic diagram of another backlight partition provided in some embodiments of the present application, such as Figure 5B As shown, the liquid crystal display screen 101 can be divided into 10 rows and 7 columns, with a total of 70 backlight partitions. Accordingly, the area of ​​each backlight partition is the same.

[0093] It is understandable that the number of the above-mentioned backlight partitions is only used for illustration and can be determined according to the actual model of the liquid crystal display device, etc.

[0094] S402: The backlight module emits backlight, which is used to adjust the backlight brightness of the displayed image.

[0095] The backlight module provides backlight for the liquid crystal display to adjust the backlight brightness of the displayed image, wherein the light source in the backlight module can be a Mini-LED backlight source.

[0096] S403: The processor obtains an average picture level APL corresponding to the images in the plurality of backlight subareas.

[0097] The average picture level (APL) indicates how much of the image is bright and how much is dark. The brighter the image is as a whole, the higher the APL value.

[0098] A possible implementation manner in which the processor obtains the average picture level APL corresponding to the image in each backlight subarea is:

[0099] The processor obtains the number of pixels and the grayscale brightness values ​​of the pixels corresponding to the images in the multiple backlight partitions, and performs average calculation based on the number of pixels and the grayscale brightness values ​​of the pixels to obtain the average image level APL corresponding to the images in the multiple backlight partitions.

[0100] In this embodiment, the processor may also directly obtain the average picture level APL corresponding to the recorded images in each backlight partition from the background parameters. It is understandable that this embodiment does not limit the method for obtaining the APL.

[0101] S404: The processor determines, according to the average picture levels APL corresponding to the images in the multiple backlight partitions, pulse width modulation (PWM) duty cycle upper limits and DC current upper limits corresponding to the images in the multiple backlight partitions.

[0102] In some embodiments, the processor determines, for any backlight partition, the pulse width modulation PWM duty cycle value and the DC current value corresponding to the image in the backlight partition when the preset upper limit power of the power supply is reached based on the average picture level APL corresponding to the image in the backlight partition, and determines the pulse width modulation PWM duty cycle value corresponding to when the preset upper limit power of the power supply is reached as the pulse width modulation PWM duty cycle upper limit value of the backlight partition, and determines the DC current value corresponding to when the preset upper limit power of the power supply is reached as the DC current upper limit value of the backlight partition.

[0103] S405. The processor determines the target backlight brightness corresponding to the multiple backlight partitions according to the average image level APL corresponding to the multiple backlight partitions and the pre-stored mapping relationship between the average image level APL and the backlight brightness. The mapping relationship has a nonlinear relationship between the average image level APL and the backlight brightness.

[0104] In this embodiment, a mapping relationship between the average picture level APL and the backlight brightness is pre-stored in the memory of the liquid crystal display device, such as a LUT display lookup table. In the LUT display lookup table, a mapping relationship between the APL and the backlight brightness value is recorded, wherein the relationship between the APL and the backlight brightness value exceeding the preset target average picture level APL is nonlinear, that is, the relationship between the APL and the backlight brightness value corresponding to the medium and high brightness areas is nonlinear.

[0105] Therefore, after the processor obtains the APL corresponding to the backlight partition a, it can determine the target backlight brightness b corresponding to the backlight partition a according to the above mapping relationship.

[0106] S406: The processor determines target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to the target backlight brightness and the corresponding PWM duty cycle upper limits of the multiple backlight partitions.

[0107] After the processor determines the target backlight brightness corresponding to each backlight partition, taking backlight partition a as an example, the target PWM duty cycle value corresponding to backlight partition a is determined based on the target backlight brightness b corresponding to backlight partition a and the PWM duty cycle upper limit value of backlight partition a determined in step S404.

[0108] The processor sends the determined target PWM duty cycle value and the corresponding DC current upper limit value corresponding to each backlight partition to the backlight module.

[0109] S407 : The backlight module adjusts the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions.

[0110] One possible implementation is:

[0111] The backlight module generates corresponding PWM control signals according to the target PWM duty cycle values ​​corresponding to multiple backlight partitions, generates corresponding DC current control signals according to the DC current upper limit values ​​corresponding to multiple backlight partitions, and adjusts the backlight brightness of the corresponding backlight partitions according to the PWM control signals and the DC current control signals.

[0112] In the above-described embodiment of the present application, the processor obtains the average picture level (APL) corresponding to the images in the multiple backlight zones and determines the pulse width modulation (PWM) duty cycle upper limits and DC current upper limits corresponding to the images in the multiple backlight zones based on the average picture level (APL) corresponding to the images in the multiple backlight zones. The processor also determines target backlight brightness corresponding to the multiple backlight zones based on the average picture level (APL) corresponding to the multiple backlight zones and a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness, wherein the relationship between the average picture level (APL) and the backlight brightness in the mapping relationship is non-linear. The processor also determines target PWM duty cycle values ​​corresponding to the multiple backlight zones based on the target backlight brightness corresponding to the multiple backlight zones and the corresponding PWM duty cycle upper limits. The backlight module then adjusts the backlight brightness of the corresponding backlight zones based on the target PWM duty cycle values ​​and the corresponding DC current upper limits corresponding to the multiple backlight zones. The non-linear relationship between the APL and the backlight brightness in the mapping relationship in the present application adjusts the backlight brightness corresponding to the APL mapping corresponding to the mid- and high-brightness areas, thereby improving the accuracy of backlight brightness adjustment in the mid- and high-brightness areas.

[0113] In some embodiments of the present application, the pre-stored mapping relationship between the average picture level APL and the backlight brightness can be obtained in the following manner: Figure 6 A flowchart of a method for obtaining a pre-stored mapping relationship between an average picture level APL and backlight brightness is provided in an embodiment of the present application. Figure 6 As shown, the method may include the following steps:

[0114] S601: The processor obtains an original mapping relationship between the average picture level APL and the backlight brightness. In the original mapping relationship, the average picture level APL and the backlight brightness are in a linear relationship.

[0115] In this embodiment, in the original mapping relationship acquired by the processor, there is a linear relationship between the average picture level APL and the backlight brightness, that is, as the APL increases, the backlight brightness increases linearly.

[0116] For example,

[0117] Taking an 8-bit panel as an example, it can display 2 to the power of 8, which is equal to 256 brightness levels. In the original mapping relationship, the backlight brightness corresponding to APL shows a linear change from 0 to 255.

[0118] S602. The processor adjusts the linear relationship in the original mapping relationship according to the preset target average picture level APL to obtain the mapping relationship between the adjusted average picture level APL and the backlight brightness. The relationship between the average picture level APL and the backlight brightness in the adjusted mapping relationship is nonlinear.

[0119] Figure 7 A flowchart of a method for obtaining a mapping relationship between an adjusted average picture level APL and backlight brightness is provided in some embodiments of the present application, such as Figure 7 As shown, the method may include the following steps:

[0120] S701: The processor determines an upper limit value of the backlight brightness according to the backlight brightness in the original mapping relationship.

[0121] Taking the 8-bit panel as an example, the processor can determine that the upper limit of the backlight brightness is 255 based on the backlight brightness in the original mapping relationship.

[0122] S702. The processor adjusts the backlight brightness corresponding to the APL exceeding the preset target average picture level APL to the upper limit of the backlight brightness according to the preset target average picture level APL, and obtains a mapping relationship between the adjusted average picture level APL and the backlight brightness.

[0123] The processor adjusts the backlight brightness corresponding to the preset target average picture level APL, assuming it is 128, to the upper limit of the backlight brightness, i.e., 255, and maintains the original backlight brightness of the APL not exceeding 128, so that the relationship between the average picture level APL and the backlight brightness is nonlinear, and a mapping relationship between the adjusted average picture level APL and the backlight brightness is obtained.

[0124] In the above example, the target average picture level APL is preset because the APL corresponding to the medium and high brightness areas is higher than the target average picture level APL. By increasing the backlight brightness corresponding to the APL that exceeds the preset target average picture level APL, the brightness of the medium and high brightness areas of the displayed image is improved.

[0125] S603: The processor stores the mapping relationship between the adjusted average picture level APL and the backlight brightness.

[0126] After obtaining the mapping relationship between the adjusted average picture level APL and the backlight brightness, the processor stores it in a preset storage unit.

[0127] In the above-described embodiment of the present application, the processor obtains an original mapping relationship between the average picture level (APL) and the backlight brightness, wherein the original mapping relationship has a linear relationship between the average picture level (APL) and the backlight brightness, and adjusts the linear relationship in the original mapping relationship based on a preset target average picture level (APL) to obtain and store an adjusted mapping relationship between the average picture level (APL) and the backlight brightness, wherein the adjusted mapping relationship has a nonlinear relationship between the average picture level (APL) and the backlight brightness. The method of this embodiment adjusts the linear original mapping relationship to a nonlinear mapping relationship, thereby making the backlight brightness subsequently determined based on the adjusted mapping relationship more accurate.

[0128] Furthermore, based on the above embodiment, the following embodiment illustrates a process in which the processor determines target PWM duty cycle values ​​corresponding to multiple backlight partitions based on target backlight brightness and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions.

[0129] Figure 8 A flow chart of a method for determining a target PWM duty cycle value corresponding to a backlight partition provided in some embodiments of the present application is shown as follows: Figure 8 As shown, the method may include the following steps:

[0130] S801: The processor determines adjustment coefficients corresponding to the multiple backlight partitions according to target backlight brightness corresponding to the multiple backlight partitions and an upper limit value of backlight brightness in a pre-stored mapping relationship between average picture level APL and backlight brightness.

[0131] For any backlight partition, the processor, based on a preset calculation algorithm, divides the target backlight brightness corresponding to the backlight partition by the upper limit value of the backlight brightness determined from the pre-stored mapping relationship between the average picture level APL and the backlight brightness to obtain the adjustment coefficient corresponding to the backlight partition.

[0132] For example,

[0133] Taking the 8-bit panel as an example, the processor determines the upper limit of the backlight brightness from the pre-stored mapping relationship between the average picture level APL and the backlight brightness as 255. Assuming that the target backlight brightness corresponding to the backlight partition a obtained by the processor is APL 分区 , then the adjustment coefficient corresponding to the backlight partition a is: APL 分区 / 255.

[0134] S802: The processor determines target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to the adjustment coefficients and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions.

[0135] For any backlight partition, the processor multiplies the adjustment coefficient corresponding to the backlight partition and the PWM duty cycle upper limit value corresponding to the backlight partition based on a preset calculation algorithm to obtain a target PWM duty cycle value corresponding to the backlight partition.

[0136] For example,

[0137] Taking the above example as an example, assuming that the adjustment coefficient of backlight partition a obtained by the processor is APL 分区 / 255, then the target PWM duty cycle value corresponding to backlight partition a is: APL 分区 / 255*PWM duty cycle upper limit.

[0138] After the processor obtains the target PWM duty cycle value corresponding to each backlight partition, it sends the target PWM duty cycle value and DC current upper limit value corresponding to each backlight partition to the BCON driver board of the LCD display. The BCON driver board sends it to the light board driver chip of the backlight module. The light board driver chip controls the LED backlight source to emit backlight corresponding to the target PWM duty cycle value and DC current upper limit value, thereby adjusting the brightness of the image in the corresponding backlight partition on the display screen.

[0139] In the above-described embodiment of the present application, the processor determines adjustment coefficients corresponding to the multiple backlight sub-areas based on the target backlight brightness corresponding to the multiple backlight sub-areas and the upper limit of the backlight brightness in a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness. The processor also determines target PWM duty cycle values ​​corresponding to the multiple backlight sub-areas based on the adjustment coefficients corresponding to the multiple backlight sub-areas and the corresponding upper limits of the PWM duty cycle. The method of this embodiment improves the accuracy of the determined target PWM duty cycle value, making the backlight brightness of the image adjusted according to the target PWM duty cycle value more accurate.

[0140] The present application also provides a computer-readable storage medium, which may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes. Specifically, the computer-readable storage medium stores computer execution instructions, and the computer execution instructions are used in the backlight brightness adjustment method of the liquid crystal display device in the above embodiment.

[0141] The present application also provides a computer program product, comprising a computer program or execution instructions, the computer program or execution instructions being stored in a readable storage medium. At least one control module of a display device can read the execution instructions from the readable storage medium, and at least one control module can execute the execution instructions to cause the display device to implement the backlight brightness adjustment method for a liquid crystal display device provided in the various embodiments described above.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0143] For ease of explanation, the above description has been presented in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments have been selected and described to better explain the principles and practical applications, thereby enabling those skilled in the art to better utilize the embodiments and various variations of the embodiments suitable for specific use considerations.

Claims

1. A liquid crystal display device, characterized in that: The liquid crystal display device comprises: A liquid crystal display screen, the liquid crystal display screen being divided into a plurality of backlight partitions, the liquid crystal display screen being configured to: display an image; a backlight module connected to the liquid crystal display screen, the backlight module being configured to: emit backlight, the backlight being used to adjust the backlight brightness of the displayed image; A processor connected to the liquid crystal display and the backlight module respectively, wherein the processor is configured to: Acquire an average picture level APL corresponding to the images in the plurality of backlight subareas; determining, according to average picture levels (APLs) corresponding to the images in the plurality of backlight partitions, upper limits of pulse width modulation (PWM) duty cycles and upper limits of DC currents corresponding to the images in the plurality of backlight partitions; determining target backlight brightness corresponding to the plurality of backlight subareas according to average picture levels (APLs) corresponding to the plurality of backlight subareas and a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness, wherein the mapping relationship has a nonlinear relationship between the average picture level (APL) and the backlight brightness; Determining target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to target backlight brightnesses and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions; The backlight module is further configured to adjust the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions.

2. The liquid crystal display device according to claim 1, wherein The processor is further configured to: Acquire an original mapping relationship between an average picture level (APL) and backlight brightness, wherein the original mapping relationship is a linear relationship between the average picture level (APL) and backlight brightness; According to a preset target average picture level APL, the linear relationship in the original mapping relationship is adjusted to obtain an adjusted mapping relationship between the average picture level APL and the backlight brightness, wherein the average picture level APL and the backlight brightness in the adjusted mapping relationship are in a nonlinear relationship; The mapping relationship between the adjusted average picture level APL and the backlight brightness is stored.

3. The liquid crystal display device according to claim 2, wherein When the processor is configured to adjust the linear relationship in the original mapping relationship according to a preset target average picture level APL to obtain an adjusted mapping relationship between the average picture level APL and the backlight brightness, the method specifically includes: Determining an upper limit value of the backlight brightness according to the backlight brightness in the original mapping relationship; According to the preset target average picture level APL, the backlight brightness corresponding to the APL exceeding the preset target average picture level APL is adjusted to the upper limit value of the backlight brightness to obtain a mapping relationship between the adjusted average picture level APL and the backlight brightness.

4. The liquid crystal display device according to claim 3, wherein When the processor is configured to obtain an average picture level APL corresponding to the images in the plurality of backlight subareas, the processor specifically includes: Obtaining the number of pixels corresponding to the images in the plurality of backlight subareas and the grayscale brightness values ​​of the pixels; An average value calculation is performed according to the number of pixels and the grayscale brightness values ​​of the pixels to obtain an average picture level APL corresponding to the images in the multiple backlight subareas.

5. The liquid crystal display device according to claim 4, wherein When the processor is configured to determine, according to the average picture levels APL corresponding to the images in the plurality of backlight partitions, the pulse width modulation (PWM) duty cycle upper limit value and the DC current upper limit value corresponding to the images in the plurality of backlight partitions, the method specifically includes: For at least one backlight partition, determining, based on an average picture level (APL) corresponding to an image in the backlight partition, a pulse width modulation (PWM) duty cycle value and a DC current value corresponding to the image when the image reaches a preset upper power limit of a power supply; Determine the pulse width modulation (PWM) duty cycle value corresponding to when the preset upper limit power of the power supply is reached as the pulse width modulation (PWM) duty cycle upper limit value of the backlight partition; The DC current value corresponding to when the preset upper limit power of the power supply is reached is determined as the DC current upper limit value of the backlight partition.

6. The liquid crystal display device according to claim 3, wherein When the processor is configured to determine the target PWM duty cycle values ​​corresponding to the multiple backlight partitions according to the target backlight brightness and the corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions, the method specifically includes: determining adjustment coefficients corresponding to the plurality of backlight subareas according to target backlight brightness corresponding to the plurality of backlight subareas and an upper limit value of backlight brightness in the pre-stored mapping relationship between average picture level APL and backlight brightness; Target PWM duty cycle values ​​corresponding to the multiple backlight partitions are determined according to the adjustment coefficients and corresponding PWM duty cycle upper limits corresponding to the multiple backlight partitions.

7. The liquid crystal display device according to claim 6, wherein When the backlight module is configured to adjust the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions, the method specifically includes: generating corresponding PWM control signals according to target PWM duty cycle values ​​corresponding to the plurality of backlight partitions; generating corresponding DC current control signals according to the DC current upper limit values ​​corresponding to the plurality of backlight partitions; The backlight brightness of the corresponding backlight partition is adjusted according to the PWM control signal and the DC current control signal.

8. A method for adjusting backlight brightness of a liquid crystal display device, characterized in that: The method comprises: The LCD screen displays images; The backlight module emits backlight, and the backlight is used to adjust the backlight brightness of the displayed image; The processor obtains an average picture level APL corresponding to the images in the plurality of backlight partitions; The processor determines, according to an average picture level (APL) corresponding to the images in the plurality of backlight partitions, a pulse width modulation (PWM) duty cycle upper limit and a DC current upper limit corresponding to the images in the plurality of backlight partitions; The processor determines target backlight brightness corresponding to the plurality of backlight subareas based on average picture levels (APLs) corresponding to the plurality of backlight subareas and a pre-stored mapping relationship between the average picture level (APL) and the backlight brightness, wherein the mapping relationship has a nonlinear relationship between the average picture level (APL) and the backlight brightness; The processor determines target PWM duty cycle values ​​corresponding to the plurality of backlight partitions according to target backlight brightness and corresponding PWM duty cycle upper limits corresponding to the plurality of backlight partitions; The backlight module adjusts the backlight brightness of the corresponding backlight partitions according to the target PWM duty cycle values ​​and the corresponding DC current upper limit values ​​corresponding to the multiple backlight partitions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by the processor, the backlight brightness adjustment method of the liquid crystal display device according to claim 8 is implemented.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the backlight brightness adjustment method of the liquid crystal display device according to claim 8 when the computer program is executed by a processor.

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