Backlight control method and device with variable refresh rate and image black insertion

Abstract

The present invention discloses a backlight control method and device for coordinated variable refresh rate and image black insertion, the method comprising: when a driver IC receives a backlight synchronization signal corresponding to a current target frame, starting a target timing process corresponding to a previous target frame, and performing black frame insertion corresponding to the previous target frame in the target timing process; after the black frame insertion corresponding to the previous target frame is completed, outputting a PWM signal corresponding to the current target frame. It can be seen that the present invention can start timing the black frame insertion time immediately upon receiving a backlight synchronization signal, without waiting for a complete cycle of a PWM signal, which not only ensures the integrity of the last PWM signal subframe, but also reduces the possibility of cumulative errors caused by the last PWM delay between driver ICs, thereby facilitating accurate coordination of black frame insertion technology in variable refresh rate scenarios, reducing motion blur and backlight delay, thereby improving the accuracy, stability and dynamic clarity of backlight control.

Description

Technical Field

[0001] The present invention relates to the field of image display technology, and in particular to a backlight control method and device with coordinated variable refresh rate and image black insertion. Background Art

[0002] VRR, or variable refresh rate for short, is a feature of monitors, TVs, and other types of displays that can significantly improve the viewing experience, from gaming to movies to web browsing. Monitors display a variety of image content, each with its own unique, varying frame rate. When the refresh rate of the display is not synchronized with the frame rate of the image content itself, users may notice unusual effects such as tearing and stuttering. On mobile devices (such as tablets and laptops), higher display refresh rates are not only redundant for static images and video playback, but also increase device power consumption and reduce battery life. These effects prompted us to look for a technology that allows the display refresh rate to adapt to the frame rate changes of the image content itself, namely VRR.

[0003] Backlight black insertion (BFI): When LCD screens flip pixels to change the display content, they cannot complete the flipping action instantly, but need to go through a gradual reversal process, during which the color state of the pixels will gradually change instead of jumping directly to the target color. Therefore, during the transition phase of flipping, specific areas on the screen will temporarily display inaccurate colors. At the same time, the human visual device has a characteristic called visual retention effect, that is, when the image in front of the eyes disappears, the visual impression of the image will continue to remain in the brain for a period of time. These two phenomena work together to cause the video screen to appear when watching dynamic images on the LCD screen. The phenomenon of motion blur is that when the human eye captures the rapidly changing image, the transition between consecutive frames becomes unclear due to the dual effects of the delay of LCD pixel flipping and the visual retention effect, thereby reducing the overall display perception. In order to effectively reduce or eliminate this motion blur phenomenon, we can cleverly insert black images (also known as black frame or black screen insertion technology) during the LCD flipping process according to the specific flipping time parameters of the LCD screen. The core of this technology is to insert a short black screen when the liquid crystal is in the flipping state to "cover" this unstable transition stage. Since the human eye cannot capture any image information during the black screen period, it cannot perceive the color inaccuracy during the flipping process, which greatly reduces the occurrence of smear and motion blur, and improves the clarity and smoothness of the dynamic picture.

[0004] With the development of display technology, in order to improve display effects and product competitiveness, many brand terminals have proposed the need for backlight black insertion under variable refresh rate. The existing solutions are briefly described as follows:

[0005] 1. When the first frame Vsync signal (vertical synchronization signal) is sent, the host computer receives, processes and sends the backlight data signal. This packet of data contains brightness information and black insertion delay information; 2. The data is sent to the driver IC (driver chip), and after the set delay time, the PWM (pulse width modulation) wave of the corresponding brightness is output; 3. Because it is impossible to know what the frame rate of the next frame is, it is necessary to send a supplementary frame before the PWM is output, so that the PWM continues to execute until the EOP (end packet) of the next data packet; 4. When the next frame Vsync (vertical synchronization signal) is sent, repeat the action of the first frame.

[0006] The existing technology currently has the following disadvantages:

[0007] Due to the limitation of OSC (crystal oscillator) frequency (about 32M) inside driver IC (driver chip), the frame rate is 512 subframes to 30.72KHz at 60Hz, and 256 subframes to 30.72KHz at 120Hz. In VRR (variable refresh rate) + BFI (backlight black insertion) applications, since the frame rate is constantly changing, in order to ensure the normal operation of driver IC, the number of PWM subframes can only be set based on the maximum frame rate. Taking the change from 60Hz to 120Hz as an example, it is required If it is set to 256 subframes, then when the frame rate is reduced, due to time issues, the driver IC (driver chip) does not receive new data after the subframe reaches 256, so it needs to repeat the current data, that is, it is necessary to send another packet of frame-filling data before executing the subframe (256 subframes) of the maximum frame rate (120Hz) to ensure the integrity of the entire frame rate. The new data will be executed only after the next data is sent. In order to ensure the integrity of the PWM subframe, sometimes even if the data comes, it is necessary to wait for this subframe to completely execute the corresponding CLK (synchronous clock) number before executing the new data. This causes the number of PWM subframes to change back and forth, which is equivalent to the frequency of PWM changing, 1 / 256=0.4%, that is, the brightness will have a relative error of ±0.4%. There is no problem with a simple 0.4% brightness difference, but the data delay between superimposed driver ICs (driver chips) will affect the visual effect, resulting in similar bright and dark blocks. On the other hand, if the Controller (backlight controller) sends data at the maximum device frame rate or an integer multiple of the maximum frame rate regardless of the device frame rate, that is, the backlight frame rate is fixed and different from the device frame rate. This method cannot fundamentally solve the VRR (variable refresh rate) + BFI (backlight black insertion) adaptation problem, and has high requirements on the logic processing and data processing speed of the Controller (backlight controller), otherwise data frame loss will occur.

[0008] In addition, when the frame rate of the display device changes instantly, if the inter-frame variation range between the previous frame and the next frame is too large, the screen will flicker. For example, if the display device fails to generate and insert the necessary intermediate frame data in a timely or effective manner when processing such a rapidly changing frame rate, then it is possible that the refresh data of the next frame will directly overwrite the intermediate frame data that should have existed for smooth transition when it is updated. This overwriting behavior will not only destroy the originally designed frame rate transition logic, but may also cause abnormal black insertion time. Abnormal adjustment of the black insertion time will directly affect the refresh rate stability of the screen and the continuity of the image, which will eventually manifest as screen flickering, greatly reducing the quality of the user's visual experience.

[0009] Finally, if the backlight data and the liquid crystal data are not precisely aligned, then during the process of the LCD panel flipping to adjust the image display, the backlight device may still be on when the second frame of liquid crystal begins to flip. This timing mismatch between the backlight and liquid crystal data will cause the regional dimming function to be unable to properly match the panel output screen, thereby causing delay problems in the screen display. Specifically, when the liquid crystal layer is flipping and the expected image is not formed, the backlight is still not turned off according to the unsynchronized data, resulting in unnecessary ghosting in the final image presented to the user, which seriously affects the clarity and smoothness of the display effect.

[0010] It can be seen that it is particularly important to provide a backlight control method that cooperates with variable refresh rate and image black insertion to improve the accuracy of backlight control when variable refresh rate and image black insertion cooperate. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide a backlight control method and device with coordinated variable refresh rate and image black insertion, which can not only improve the accuracy of backlight control with coordinated variable refresh rate and image black insertion, but also improve the stability and dynamic clarity of backlight control in the coordinated mode of variable refresh rate and image black insertion, and optimize visual smoothness and image quality.

[0012] In order to solve the above technical problems, the first aspect of the present invention discloses a backlight control method with variable refresh rate and image black insertion, the method is applied to a control system, the control system includes a backlight controller and at least one driver IC, the method includes:

[0013] When the driver IC receives the backlight synchronization signal corresponding to the current target frame, the target timing process corresponding to the previous target frame is started, and the black frame insertion operation corresponding to the previous target frame is performed during the target timing process; the backlight synchronization signal is a signal from the backlight controller for synchronization of the driver IC;

[0014] After the black frame insertion operation corresponding to the previous target frame is completed, a PWM signal corresponding to the current target frame is output; the PWM signal is used to adjust the backlight brightness of the target frame.

[0015] As an optional embodiment, in the first aspect of the present invention, the method further comprises:

[0016] Determine a frame rate range required for a first target task, and determine a first intermediate frame rate based on the frame rate range required for the first target task; the first target task is an image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task;

[0017] Based on the first intermediate frame rate, determining a first initial sending time of a backlight controller to send a backlight synchronization signal corresponding to each target frame;

[0018] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame;

[0019] Based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

[0020] As an optional implementation, in the first aspect of the present invention, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame, including:

[0021] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, determining the brightness value change trend and the brightness value change ratio of the PWM signal corresponding to the current target frame; the brightness value change trend includes brightening and darkening;

[0022] If the brightness value change trend of the PWM signal corresponding to the current target frame is brightening, based on the brightness value change ratio corresponding to the current target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is before the first initial sending time;

[0023] If the brightness value change trend of the PWM signal corresponding to the current target frame is dimming, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value change ratio corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is after the first initial sending time.

[0024] As an optional embodiment, in the first aspect of the present invention, the method further comprises:

[0025] Based on the target brightness value of the PWM signal corresponding to the previous target frame, the initial brightness value of the PWM signal corresponding to the current target frame and the time filter coefficient, the target brightness value of the PWM signal corresponding to the current target frame is determined; the initial brightness value of the PWM signal corresponding to the current target frame represents the unprocessed brightness value of the current target frame; the target brightness value of the PWM signal corresponding to the current target frame represents the smooth transition brightness value after processing of the current target frame; the time filter coefficient is determined based on the target brightness values ​​of several target frames before the current target frame or is set by the user;

[0026] Among them, the calculation formula of the target brightness value of the PWM signal corresponding to the current target frame is as follows:

[0027]

[0028] Where L represents the target brightness value of the PWM signal corresponding to the current target frame; New L Indicates the initial brightness value of the PWM signal corresponding to the current target frame; X represents the time filter coefficient; Old L Indicates the target brightness value of the PWM signal corresponding to the previous target frame.

[0029] As an optional implementation, in the first aspect of the present invention, the temporal filter coefficient is determined based on target brightness values ​​of two target frames before the current target frame;

[0030] And, the method further comprises:

[0031] Determine a frame rate range required for a second target task, and determine a second intermediate frame rate based on the frame rate range required for the second target task; the second target task is an image display task currently executed based on the control system; the second intermediate frame rate is within the frame rate range required for the second target task;

[0032] Based on the second intermediate frame rate, determining a second initial sending time for the backlight controller to send a backlight synchronization signal corresponding to each target frame;

[0033] Based on the target brightness value of the PWM signal corresponding to the current target frame and the target brightness value of the PWM signal corresponding to the previous target frame, the second initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the second target sending time of the backlight synchronization signal corresponding to the current target frame;

[0034] Based on the second target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

[0035] As an optional implementation, in the first aspect of the present invention, the PWM signal corresponding to the target frame is a continuous output signal and the frequency of the PWM signal corresponding to the target frame is a fixed frequency adjustable by a register; when the driver IC receives the backlight synchronization signal corresponding to the current target frame, the subframe number of the PWM signal corresponding to the previous target frame will be switched to the subframe number of the PWM signal corresponding to the current target frame;

[0036] The frequency and subframe number of the PWM signal corresponding to the target frame are determined by the following formula:

[0037] Frequency = OSC frequency / PWM accuracy

[0038] PWM sub-frame number = OSC frequency / PWM accuracy / frame rate

[0039] The OSC frequency is determined based on the driver IC, the PWM precision refers to the minimum adjustable unit of the duty cycle corresponding to the PWM signal; and the frame rate refers to the frame rate of the current target frame.

[0040] As an optional implementation, in the first aspect of the present invention, the PWM signal corresponding to the target frame is determined based on the backlight data received, processed and sent by the backlight controller.

[0041] The second aspect of the present invention discloses a backlight control device with variable refresh rate and image black insertion, the device comprising:

[0042] A timing module, configured to start a target timing process corresponding to a previous target frame and perform a black frame insertion operation corresponding to the previous target frame during the target timing process when the driver IC receives a backlight synchronization signal corresponding to the current target frame; the backlight synchronization signal is a signal from a backlight controller for synchronization of the driver IC;

[0043] The output module is used to output a PWM signal corresponding to the current target frame after the black frame insertion operation corresponding to the previous target frame is completed; the PWM signal is used to adjust the backlight brightness of the target frame.

[0044] As an optional implementation, in the second aspect of the present invention, the device further includes:

[0045] A first determination module is used to determine the frame rate range required for a first target task, and to determine a first intermediate frame rate based on the frame rate range required for the first target task; the first target task is an image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task; based on the first intermediate frame rate, determine a first initial sending time of a backlight synchronization signal corresponding to each target frame sent by the backlight controller; based on the brightness value of a PWM signal corresponding to the current target frame and the brightness value of a PWM signal corresponding to a previous target frame, adjust the first initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain a first target sending time of the backlight synchronization signal corresponding to the current target frame; based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, send the backlight synchronization signal corresponding to the current target frame to the driver IC through the backlight controller.

[0046] As an optional implementation, in the second aspect of the present invention, the first determination module adjusts the first initial sending time of the backlight synchronization signal corresponding to the current target frame based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame, and the specific method includes:

[0047] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, determining the brightness value change trend and the brightness value change ratio of the PWM signal corresponding to the current target frame; the brightness value change trend includes brightening and darkening;

[0048] If the brightness value change trend of the PWM signal corresponding to the current target frame is brightening, based on the brightness value change ratio corresponding to the current target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is before the first initial sending time;

[0049] If the brightness value change trend of the PWM signal corresponding to the current target frame is dimming, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value change ratio corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is after the first initial sending time.

[0050] As an optional implementation, in the second aspect of the present invention, the device further includes:

[0051] The transition module is used to determine the target brightness value of the PWM signal corresponding to the current target frame based on the target brightness value of the PWM signal corresponding to the previous target frame, the initial brightness value of the PWM signal corresponding to the current target frame, and the time filtering coefficient; the initial brightness value of the PWM signal corresponding to the current target frame represents the unprocessed brightness value of the current target frame; the target brightness value of the PWM signal corresponding to the current target frame represents the smooth transition brightness value after the current target frame is processed; the time filtering coefficient is determined based on the target brightness values ​​of several target frames before the current target frame or is set by the user; wherein, the calculation formula of the target brightness value of the PWM signal corresponding to the current target frame is as follows:

[0052]

[0053] Where L represents the target brightness value of the PWM signal corresponding to the current target frame; New L Indicates the initial brightness value of the PWM signal corresponding to the current target frame; X represents the time filter coefficient; Old L Indicates the target brightness value of the PWM signal corresponding to the previous target frame.

[0054] As an optional implementation, in the second aspect of the present invention, the temporal filtering coefficient is determined based on target brightness values ​​of two target frames before the current target frame; and the device further includes:

[0055] A second determination module is used to determine the frame rate range required for the second target task, and determine the second intermediate frame rate based on the frame rate range required for the second target task; the second target task is an image display task currently executed based on the control system; the second intermediate frame rate is within the frame rate range required for the second target task; based on the second intermediate frame rate, determine the second initial sending time of the backlight synchronization signal corresponding to each target frame sent by the backlight controller; based on the target brightness value of the PWM signal corresponding to the current target frame and the target brightness value of the PWM signal corresponding to the previous target frame, adjust the second initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain the second target sending time of the backlight synchronization signal corresponding to the current target frame; based on the second target sending time of the backlight synchronization signal corresponding to the current target frame, send the backlight synchronization signal corresponding to the current target frame to the driver IC through the backlight controller.

[0056] As an optional implementation, in the second aspect of the present invention, the PWM signal corresponding to the target frame is a continuous output signal and the frequency of the PWM signal corresponding to the target frame is a fixed frequency adjustable by a register; when the driver IC receives the backlight synchronization signal corresponding to the current target frame, the subframe number of the PWM signal corresponding to the previous target frame will be switched to the subframe number of the PWM signal corresponding to the current target frame;

[0057] The frequency and subframe number of the PWM signal corresponding to the target frame are determined by the following formula:

[0058] Frequency = OSC frequency / PWM accuracy

[0059] PWM sub-frame number = OSC frequency / PWM accuracy / frame rate

[0060] The OSC frequency is determined based on the driver IC, the PWM precision refers to the minimum adjustable unit of the duty cycle corresponding to the PWM signal; and the frame rate refers to the frame rate of the current target frame.

[0061] As an optional implementation, in the second aspect of the present invention, the PWM signal corresponding to the target frame is determined based on the backlight data received, processed and sent by the backlight controller.

[0062] The third aspect of the present invention discloses a backlight control system with a variable refresh rate and image black insertion, the system comprising:

[0063] A memory storing executable program code;

[0064] a processor coupled to the memory;

[0065] The processor calls the executable program code stored in the memory to execute the steps of the backlight control method with coordinated variable refresh rate and image black insertion disclosed in the first aspect of the present invention.

[0066] The fourth aspect of the present invention discloses a computer storage medium, which stores computer instructions. When the computer instructions are called, they are used to execute the steps in the backlight control method with variable refresh rate and image black insertion coordinated disclosed in the first aspect of the present invention.

[0067] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0068] The present invention starts the target timing process of black frame insertion corresponding to the target frame when the driver IC receives the backlight synchronization signal corresponding to the target frame, and outputs the PWM signal corresponding to the target frame during the target timing process; it can be seen that the present invention can start the target timing process corresponding to the previous target frame when the driver IC receives the backlight synchronization signal corresponding to the current target frame, and perform the black frame insertion corresponding to the previous target frame during the target timing process; after the black frame insertion corresponding to the previous target frame is completed, the PWM signal corresponding to the current target frame is output. It can be seen that the present invention can start timing the black frame insertion time immediately upon receiving the backlight synchronization signal, without waiting for the complete cycle of the PWM signal, which not only ensures the integrity of the last PWM signal subframe, but also reduces the possibility of cumulative errors caused by the last PWM delay between driver ICs, which is conducive to the precise coordination of black frame insertion technology in variable refresh rate scenarios, reduces dynamic blur and backlight delay, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual fluency and image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0070] Figure 1 It is a flow chart of a backlight control method with coordinated variable refresh rate and image black insertion disclosed in an embodiment of the present invention;

[0071] Figure 2 It is a timing diagram of a backlight control method for coordinated variable refresh rate and image black insertion disclosed in an embodiment of the present invention;

[0072] Figure 3 It is a structural schematic diagram of a backlight control device with variable refresh rate and image black insertion coordination disclosed in an embodiment of the present invention;

[0073] Figure 4 It is a structural schematic diagram of a backlight control system with a variable refresh rate and image black insertion coordinated according to an embodiment of the present invention. DETAILED DESCRIPTION

[0074] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or end including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or ends.

[0076] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0077] The present invention discloses a backlight control method and device for coordinated variable refresh rate and image black insertion. The method described in the embodiment of the present invention can start timing the black frame insertion time immediately upon receiving the backlight synchronization signal, without waiting for the complete cycle of the PWM signal, which not only ensures the integrity of the last PWM signal subframe, but also reduces the possibility of cumulative errors caused by the last PWM delay between driver ICs, thereby facilitating accurate coordination of black frame insertion technology in variable refresh rate scenarios, reducing dynamic blur and backlight delay, thereby improving the accuracy, stability and dynamic clarity of backlight control in the coordinated mode of variable refresh rate and image black insertion, and optimizing visual fluency and image quality. The following are detailed descriptions.

[0078] Embodiment 1

[0079] See also Figure 1 , Figure 1 1 is a flow chart of a backlight control method for a variable refresh rate and image black insertion coordination disclosed in an embodiment of the present invention. Figure 1The described method can be applied to any backlight control scenario where a variable refresh rate is coordinated with image black insertion, such as a backlight control scenario where an LCD screen flips pixels to change the displayed content, and the embodiments of the present invention are not limited thereto. Figure 1 As shown, the backlight control method with variable refresh rate and image black insertion includes the following operations:

[0080] 101. When the driver IC receives the backlight synchronization signal corresponding to the current target frame, it starts the target timing process corresponding to the previous target frame, and performs the black frame insertion operation corresponding to the previous target frame during the target timing process;

[0081] 102. After the black frame insertion operation corresponding to the previous target frame is completed, a PWM signal corresponding to the current target frame is output;

[0082] In the embodiment of the present invention, the timing diagram of the backlight control method with variable refresh rate and image black insertion is as follows: Figure 2 As shown, the timing diagram includes the timing of vertical synchronization model, synchronous serial interface, screen display, backlight data, liquid crystal data, backlight synchronization signal, PWM and dynamic liquid crystal flip; in order to ensure that the backlight brightness of each frame is consistent as much as possible, we introduce the new concept of backlight synchronization signal (BL_Vsync), which is a signal from the backlight controller for driving IC synchronization, and can be flexibly adjusted in advance or delay in time according to different panel requirements and specific conditions. It can be clearly seen from the timing diagram that the system Vsync signal (vertical synchronization signal) of each target frame occurs before the backlight synchronization signal (BL_Vsync), which means that when the Vsync signal of the display system of each target frame is issued, this embodiment can already know the frame frequency information of the previous target frame. Based on this feature, we only need to grasp the frame frequency of the previous target frame of the system, and we can make brightness compensation of the corresponding frequency for the backlight black insertion time of the current target frame. Further, the target timing process is used to determine the time length of black frame insertion; the PWM signal is used to adjust the backlight brightness of the target frame. It is understandable that when the driver IC receives the backlight synchronization signal and starts timing the black frame insertion time, the last PWM signal of the previous frame will also be fully executed. This design ensures that the backlight driver and the LCD display are fully synchronized, avoiding screen tearing or ghosting caused by the backlight and screen being out of sync.

[0083] It can be seen that this embodiment can start timing the black frame insertion time immediately upon receiving the backlight synchronization signal, without waiting for the complete cycle of the PWM signal, which not only ensures the integrity of the last PWM signal subframe, but also reduces the possibility of cumulative errors caused by the last PWM delay between driver ICs, which is beneficial to the precise cooperation of black frame insertion technology in variable refresh rate scenarios, reduces motion blur and backlight delay, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0084] In an optional embodiment, the method may further include:

[0085] Determine a frame rate range required for a first target task, and determine a first intermediate frame rate based on the frame rate range required for the first target task; the first target task is an image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task;

[0086] Based on the first intermediate frame rate, determining a first initial sending time of the backlight controller to send a backlight synchronization signal corresponding to each target frame;

[0087] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame;

[0088] Based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

[0089] In this optional embodiment, the center frame rate is used as a reference for subsequent compensation. For example, if the application requirement varies between 90 Hz and 120 Hz, the center frequency can be set to 105 Hz.

[0090] It can be seen that this optional embodiment can determine the first intermediate frame rate based on the frame rate range required by the first target task, and determine the first initial sending time of the backlight synchronization signal based on the first intermediate frame rate, and adjust the first initial sending time according to the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time, which is beneficial to improve the accuracy of determining the first target sending time, and then improve the accuracy of black frame insertion, and effectively realize the compensation of backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0091] In another optional embodiment, based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, adjusting the first initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame may include:

[0092] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, determining the brightness value change trend and the brightness value change ratio of the PWM signal corresponding to the current target frame; the brightness value change trend includes brightening and darkening;

[0093] If the brightness value change trend of the PWM signal corresponding to the current target frame is brightening, based on the brightness value change ratio corresponding to the current target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is before the first initial sending time;

[0094] If the brightness value change trend of the PWM signal corresponding to the current target frame is darkening, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value change ratio corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is after the first initial sending time.

[0095] In this optional embodiment, it can be understood that when the frame rate changes from high to low, the number of PWM subframes increases, and the brightness shows an upward trend. At this time, we need to reduce the black insertion time according to the degree of brightness increase; when the frame rate changes from low to high, the number of PWM subframes decreases, and the brightness shows a downward trend. At this time, we also need to adjust the black insertion time according to the degree of brightness reduction; further, the proportion of the adjustment of the first initial transmission time should be consistent with the proportion of the brightness value change. Through the above steps, we can effectively compensate for the backlight brightness according to the frame rate change, thereby ensuring that the backlight brightness of each frame remains consistent.

[0096] It can be seen that this optional embodiment can determine the brightness value change trend and brightness value change ratio of the PWM signal corresponding to the current target frame based on the brightness values ​​of the PWM signal corresponding to the current target frame and the previous target frame, and further obtain the adjustment method of the first initial sending time, which is conducive to improving the accuracy of determining the first target sending time, and then improving the accuracy of black frame insertion, and effectively realizing compensation for backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0097] In yet another optional embodiment, the method may further include:

[0098] Based on the target brightness value of the PWM signal corresponding to the previous target frame, the initial brightness value of the PWM signal corresponding to the current target frame and the time filter coefficient, the target brightness value of the PWM signal corresponding to the current target frame is determined; the initial brightness value of the PWM signal corresponding to the current target frame represents the unprocessed brightness value of the current target frame; the target brightness value of the PWM signal corresponding to the current target frame represents the smooth transition brightness value after processing of the current target frame; the time filter coefficient is determined based on the target brightness values ​​of several target frames before the current target frame or is set by the user;

[0099] Among them, the calculation formula of the target brightness value of the PWM signal corresponding to the current target frame is as follows:

[0100]

[0101] Where L represents the target brightness value of the PWM signal corresponding to the current target frame; New L Indicates the initial brightness value of the PWM signal corresponding to the current target frame; X represents the time filter coefficient; Old L Indicates the target brightness value of the PWM signal corresponding to the previous target frame.

[0102] In this optional embodiment, during the frame rate change, the duty cycle is also continuously adjusted, which inevitably leads to a corresponding change in brightness. The frame rate change may be gradual or drastic, but in any case, a sudden change in brightness may have an adverse effect on the user experience. Therefore, the abrupt change in brightness when the frame rate changes can be reduced by achieving brightness continuity and smooth transition.

[0103] In this optional embodiment, the temporal filter coefficient is determined based on the target brightness values ​​of several target frames before the current target frame. It can be determined based on the change ratio of the target brightness values ​​of two target frames before the current target frame, or it can be determined based on the continuous change amplitude of the target brightness values ​​of more target frames, which is not limited by the embodiment of the present invention.

[0104] It can be seen that this optional embodiment can adjust the brightness of each frame through the brightness data between different frames, and can further determine the target brightness value of the PWM signal corresponding to the current target frame, so that the brightness change is smoother and more natural when the frame rate changes, which is beneficial to reduce the impact of sudden brightness changes on user experience and improve the overall look and feel of the display system in VRR+BFI mode.

[0105] In yet another optional embodiment, the temporal filter coefficient is determined based on target brightness values ​​of two target frames before the current target frame;

[0106] And, the method may further include:

[0107] Determine a frame rate range required for a second target task, and determine a second intermediate frame rate based on the frame rate range required for the second target task; the second target task is an image display task currently executed based on the control system; and the second intermediate frame rate is within the frame rate range required for the second target task;

[0108] Based on the second intermediate frame rate, determining a second initial sending time for the backlight controller to send a backlight synchronization signal corresponding to each target frame;

[0109] Based on the target brightness value of the PWM signal corresponding to the current target frame and the target brightness value of the PWM signal corresponding to the previous target frame, the second initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the second target sending time of the backlight synchronization signal corresponding to the current target frame;

[0110] Based on the second target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

[0111] It can be seen that this optional embodiment can determine the second intermediate frame rate based on the frame rate range required by the second target task, and determine the second initial sending time of the backlight synchronization signal based on the second intermediate frame rate, and adjust the first initial sending time to obtain the second target sending time according to the processed target brightness value of the PWM signal corresponding to the current target frame and the previous target frame, which is beneficial to improve the accuracy of determining the second target sending time, and then improve the accuracy of black frame insertion, and effectively realize the compensation of backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0112] In another optional embodiment, the PWM signal corresponding to the target frame is a continuous output signal and the frequency of the PWM signal corresponding to the target frame is a fixed frequency adjustable by a register; when the driver IC receives the backlight synchronization signal corresponding to the current target frame, the subframe number of the PWM signal corresponding to the previous target frame will be switched to the subframe number of the PWM signal corresponding to the current target frame;

[0113] Among them, the frequency and subframe number of the PWM signal corresponding to the target frame are determined by the following formula:

[0114] Frequency = OSC frequency / PWM accuracy

[0115] PWM sub-frame number = OSC frequency / PWM accuracy / frame rate

[0116] The OSC frequency is determined based on the driver IC. The PWM precision refers to the minimum adjustable unit of the duty cycle corresponding to the PWM signal. The frame rate refers to the frame rate of the current target frame.

[0117] In this optional embodiment, it can be understood that when the PWM frequency remains unchanged and the frame frequency changes (such as from 120Hz to 60Hz), there is no need to insert additional frame data (i.e., fill frame) when the PWM signal is output to half. Furthermore, when the driver IC receives the backlight synchronization signal corresponding to the current target frame, it can adapt the frame frequency and switch to the subframe number of the PWM frequency corresponding to the current target frame. In this optional embodiment, for PWM accuracy, for example, if the PWM accuracy is 100, then the smallest adjustment unit is 1%; if the PWM accuracy is 1000, then the smallest adjustment unit is 0.1%.

[0118] It can be seen that this optional embodiment can continuously output PWM signals at a fixed frequency, ensuring the integrity of the last PWM subframe, reducing the possibility of backlight flickering caused by the next frame data covering the supplementary frame data of the previous frame, and at the same time can determine the PWM frequency and the number of PWM subframes, which is conducive to improving the accuracy of determining the frequency and the number of subframes, thereby improving the accuracy of backlight control and achieving perfect synchronization between the PWM signal and the liquid crystal flip, thereby improving the dynamic clarity and stability of the picture, and improving the display performance and user experience of the display system.

[0119] In yet another optional embodiment, the PWM signal corresponding to the target frame is determined based on the backlight data received, processed and sent by the backlight controller.

[0120] It can be seen that this optional embodiment can further determine the method for obtaining the PWM signal, which is beneficial to improving the accuracy of determining the PWM signal, and further improving the accuracy of the PWM signal backlight control.

[0121] Embodiment 2

[0122] See also Figure 3 , Figure 3 1 is a schematic diagram of a backlight control device with variable refresh rate and image black insertion according to an embodiment of the present invention. Figure 3 The described device can be applied to any backlight control scenario where a variable refresh rate and image black insertion are coordinated, such as a backlight control scenario where an LCD screen flips pixels to change the displayed content, and the embodiments of the present invention are not limited thereto. Figure 3 As shown, the backlight control device with variable refresh rate and image black insertion may include:

[0123] The timing module 201 is used to start the target timing process corresponding to the previous target frame when the driver IC receives the backlight synchronization signal corresponding to the current target frame, and perform the black frame insertion operation corresponding to the previous target frame during the target timing process; the backlight synchronization signal is a signal from the backlight controller for driver IC synchronization;

[0124] The output module 202 is used to output a PWM signal corresponding to the current target frame after the black frame insertion operation corresponding to the previous target frame is completed; the PWM signal is used to adjust the backlight brightness of the target frame.

[0125] It can be seen that the device described in the implementation of this embodiment can start timing the black frame insertion time immediately upon receiving the backlight synchronization signal, without waiting for the complete cycle of the PWM signal, which not only ensures the integrity of the last PWM signal subframe, but also reduces the possibility of cumulative errors caused by the last PWM delay between driver ICs, which is beneficial to the precise cooperation of black frame insertion technology in variable refresh rate scenarios, reduces motion blur and backlight delay, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0126] In an optional embodiment, the device may further include:

[0127] The first determination module is used to determine the frame rate range required for the first target task, and determine the first intermediate frame rate based on the frame rate range required for the first target task; the first target task is the image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task; based on the first intermediate frame rate, determine the first initial sending time of the backlight synchronization signal corresponding to each target frame sent by the backlight controller; based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, adjust the first initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, send the backlight synchronization signal corresponding to the current target frame to the driver IC through the backlight controller.

[0128] It can be seen that this optional embodiment can determine the first intermediate frame rate based on the frame rate range required by the first target task, and determine the first initial sending time of the backlight synchronization signal based on the first intermediate frame rate, and adjust the first initial sending time according to the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time, which is beneficial to improve the accuracy of determining the first target sending time, and then improve the accuracy of black frame insertion, and effectively realize the compensation of backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0129] In another optional embodiment, the first determination module adjusts the first initial sending time of the backlight synchronization signal corresponding to the current target frame based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame, and the specific method includes:

[0130] Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, determining the brightness value change trend and the brightness value change ratio of the PWM signal corresponding to the current target frame; the brightness value change trend includes brightening and darkening;

[0131] If the brightness value change trend of the PWM signal corresponding to the current target frame is brightening, based on the brightness value change ratio corresponding to the current target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is before the first initial sending time;

[0132] If the brightness value change trend of the PWM signal corresponding to the current target frame is darkening, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value change ratio corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is after the first initial sending time.

[0133] It can be seen that this optional embodiment can determine the brightness value change trend and brightness value change ratio of the PWM signal corresponding to the current target frame based on the brightness values ​​of the PWM signal corresponding to the current target frame and the previous target frame, and further obtain the adjustment method of the first initial sending time, which is conducive to improving the accuracy of determining the first target sending time, and then improving the accuracy of black frame insertion, and effectively realizing compensation for backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0134] In yet another optional embodiment, the device may further include:

[0135] The transition module is used to determine the target brightness value of the PWM signal corresponding to the current target frame based on the target brightness value of the PWM signal corresponding to the previous target frame, the initial brightness value of the PWM signal corresponding to the current target frame, and the time filtering coefficient; the initial brightness value of the PWM signal corresponding to the current target frame represents the unprocessed brightness value of the current target frame; the target brightness value of the PWM signal corresponding to the current target frame represents the smooth transition brightness value after the current target frame is processed; the time filtering coefficient is determined based on the target brightness values ​​of several target frames before the current target frame or is set by the user; wherein, the calculation formula of the target brightness value of the PWM signal corresponding to the current target frame is as follows:

[0136]

[0137] Where L represents the target brightness value of the PWM signal corresponding to the current target frame; New L Indicates the initial brightness value of the PWM signal corresponding to the current target frame; X represents the time filter coefficient; Old L Indicates the target brightness value of the PWM signal corresponding to the previous target frame.

[0138] It can be seen that this optional embodiment can adjust the brightness of each frame through the brightness data between different frames, and can further determine the target brightness value of the PWM signal corresponding to the current target frame, so that the brightness change is smoother and more natural when the frame rate changes, which is beneficial to reduce the impact of sudden brightness changes on user experience and improve the overall look and feel of the display system in VRR+BFI mode.

[0139] In yet another optional embodiment, the temporal filtering coefficient is determined based on target brightness values ​​of two target frames before the current target frame; and the apparatus may further include:

[0140] The second determination module is used to determine the frame rate range required for the second target task, and determine the second intermediate frame rate based on the frame rate range required for the second target task; the second target task is the image display task currently executed based on the control system; the second intermediate frame rate is within the frame rate range required for the second target task; based on the second intermediate frame rate, determine the second initial sending time of the backlight synchronization signal corresponding to each target frame sent by the backlight controller; based on the target brightness value of the PWM signal corresponding to the current target frame and the target brightness value of the PWM signal corresponding to the previous target frame, adjust the second initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain the second target sending time of the backlight synchronization signal corresponding to the current target frame; based on the second target sending time of the backlight synchronization signal corresponding to the current target frame, send the backlight synchronization signal corresponding to the current target frame to the driver IC through the backlight controller.

[0141] It can be seen that this optional embodiment can determine the first intermediate frame rate based on the frame rate range required by the second target task, and determine the second initial sending time of the backlight synchronization signal based on the second intermediate frame rate, and adjust the second initial sending time according to the processed target brightness value of the PWM signal corresponding to the current target frame and the previous target frame to obtain the second target sending time, which is beneficial to improve the accuracy of determining the second target sending time, and then improve the accuracy of black frame insertion, and effectively realize the compensation of backlight brightness according to frame rate changes, thereby improving the accuracy, stability and dynamic clarity of backlight control in the variable refresh rate and image black insertion collaborative mode, and optimizing visual smoothness and image quality.

[0142] In another optional embodiment, the PWM signal corresponding to the target frame is a continuous output signal and the frequency of the PWM signal corresponding to the target frame is a fixed frequency adjustable by a register; when the driver IC receives the backlight synchronization signal corresponding to the current target frame, the subframe number of the PWM signal corresponding to the previous target frame will be switched to the subframe number of the PWM signal corresponding to the current target frame;

[0143] Among them, the frequency and subframe number of the PWM signal corresponding to the target frame are determined by the following formula:

[0144] Frequency = OSC frequency / PWM accuracy

[0145] PWM sub-frame number = OSC frequency / PWM accuracy / frame rate

[0146] The OSC frequency is determined based on the driver IC. The PWM precision refers to the minimum adjustable unit of the duty cycle corresponding to the PWM signal. The frame rate refers to the frame rate of the current target frame.

[0147] It can be seen that this optional embodiment can continuously output PWM signals at a fixed frequency, ensuring the integrity of the last PWM subframe, reducing the possibility of backlight flickering caused by the next frame data covering the supplementary frame data of the previous frame, and at the same time can determine the PWM frequency and the number of PWM subframes, which is conducive to improving the accuracy of determining the frequency and the number of subframes, thereby improving the accuracy of backlight control and achieving perfect synchronization between the PWM signal and the liquid crystal flip, thereby improving the dynamic clarity and stability of the picture, and improving the display performance and user experience of the display system.

[0148] In yet another optional embodiment, the PWM signal corresponding to the target frame is determined based on the backlight data received, processed and sent by the backlight controller.

[0149] It can be seen that this optional embodiment can further determine the method for obtaining the PWM signal, which is beneficial to improving the accuracy of determining the PWM signal, and further improving the accuracy of the PWM signal backlight control.

[0150] Embodiment 3

[0151] See also Figure 4 , Figure 4 1 is a schematic diagram of a backlight control system with a variable refresh rate and image black insertion according to an embodiment of the present invention. Figure 4 The variable refresh rate and image black insertion coordinated backlight control system shown may include:

[0152] A memory 301 storing executable program codes;

[0153] a processor 302 coupled to the memory 301;

[0154] The processor 302 calls the executable program code stored in the memory 301 to execute the steps of the backlight control method with coordinated variable refresh rate and image black insertion described in the first embodiment of the present invention.

[0155] Embodiment 4

[0156] An embodiment of the present invention discloses a computer storage medium storing computer instructions. When the computer instructions are called, they are used to execute the steps of the backlight control method with variable refresh rate and image black insertion described in the first embodiment of the present invention.

[0157] Embodiment 5

[0158] An embodiment of the present invention discloses a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to enable a computer to execute the steps of the backlight control method with variable refresh rate and image black insertion described in Example 1.

[0159] The device embodiments described above are only illustrative, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, i.e., they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0160] Through the specific description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solution can be essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0161] Finally, it should be noted that the variable refresh rate and image black insertion coordinated backlight control method and device disclosed in the embodiment of the present invention only disclose the preferred embodiments of the present invention, which are only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A backlight control method with variable refresh rate and image black insertion, characterized in that: The method is applied to a control system, the control system includes a backlight controller and at least one driver IC, and the method includes: When the driver IC receives the backlight synchronization signal corresponding to the current target frame, the target timing process corresponding to the previous target frame is started, and the black frame insertion operation corresponding to the previous target frame is performed during the target timing process; the backlight synchronization signal is a signal from the backlight controller for synchronization of the driver IC; After the black frame insertion operation corresponding to the previous target frame is completed, a PWM signal corresponding to the current target frame is output; the PWM signal is used to adjust the backlight brightness of the target frame; The method further comprises: Determine a frame rate range required for a first target task, and determine a first intermediate frame rate based on the frame rate range required for the first target task; the first target task is an image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task; Based on the first intermediate frame rate, determining a first initial sending time of a backlight controller to send a backlight synchronization signal corresponding to each target frame; Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; Based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

2. The backlight control method with variable refresh rate and image black insertion as claimed in claim 1, characterized in that: The method of adjusting the first initial sending time of the backlight synchronization signal corresponding to the current target frame based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame includes: Based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, determining the brightness value change trend and the brightness value change ratio of the PWM signal corresponding to the current target frame; the brightness value change trend includes brightening and darkening; If the brightness value change trend of the PWM signal corresponding to the current target frame is brightening, based on the brightness value change ratio corresponding to the current target frame, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is before the first initial sending time; If the brightness value change trend of the PWM signal corresponding to the current target frame is dimming, the first initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted based on the brightness value change ratio corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; the first target sending time is after the first initial sending time.

3. The backlight control method with variable refresh rate and image black insertion as claimed in claim 1, characterized in that: The method further comprises: Based on the target brightness value of the PWM signal corresponding to the previous target frame, the initial brightness value of the PWM signal corresponding to the current target frame and the time filter coefficient, the target brightness value of the PWM signal corresponding to the current target frame is determined; the initial brightness value of the PWM signal corresponding to the current target frame represents the unprocessed brightness value of the current target frame; the target brightness value of the PWM signal corresponding to the current target frame represents the smooth transition brightness value after processing of the current target frame; the time filter coefficient is determined based on the target brightness values ​​of several target frames before the current target frame or is set by the user; Among them, the calculation formula of the target brightness value of the PWM signal corresponding to the current target frame is as follows: Where L represents the target brightness value of the PWM signal corresponding to the current target frame; New L Indicates the initial brightness value of the PWM signal corresponding to the current target frame; X represents the time filter coefficient; Old L Indicates the target brightness value of the PWM signal corresponding to the previous target frame.

4. The backlight control method with variable refresh rate and image black insertion as claimed in claim 3, characterized in that: The temporal filtering coefficient is determined based on the target brightness values ​​of two target frames before the current target frame; And, the method further comprises: Determine a frame rate range required for a second target task, and determine a second intermediate frame rate based on the frame rate range required for the second target task; the second target task is an image display task currently executed based on the control system; the second intermediate frame rate is within the frame rate range required for the second target task; Based on the second intermediate frame rate, determining a second initial sending time for the backlight controller to send a backlight synchronization signal corresponding to each target frame; Based on the target brightness value of the PWM signal corresponding to the current target frame and the target brightness value of the PWM signal corresponding to the previous target frame, the second initial sending time of the backlight synchronization signal corresponding to the current target frame is adjusted to obtain the second target sending time of the backlight synchronization signal corresponding to the current target frame; Based on the second target sending time of the backlight synchronization signal corresponding to the current target frame, the backlight synchronization signal corresponding to the current target frame is sent to the driver IC through the backlight controller.

5. The backlight control method with variable refresh rate and image black insertion as claimed in any one of claims 1 to 4, characterized in that: The PWM signal corresponding to the target frame is a continuous output signal and the frequency of the PWM signal corresponding to the target frame is a fixed frequency adjustable by a register; when the driver IC receives the backlight synchronization signal corresponding to the current target frame, the subframe number of the PWM signal corresponding to the previous target frame will be switched to the subframe number of the PWM signal corresponding to the current target frame; The frequency and subframe number of the PWM signal corresponding to the target frame are determined by the following formula: Frequency = OSC frequency / PWM accuracy PWM sub-frame number = OSC frequency / PWM accuracy / frame rate The OSC frequency is determined based on the driver IC, the PWM precision refers to the minimum adjustable unit of the duty cycle corresponding to the PWM signal; and the frame rate refers to the frame rate of the current target frame.

6. The backlight control method with variable refresh rate and image black insertion as claimed in claim 5, characterized in that: The PWM signal corresponding to the target frame is determined based on the backlight data received, processed and sent by the backlight controller.

7. A backlight control device with variable refresh rate and image black insertion, characterized in that: The device comprises: A timing module, configured to start a target timing process corresponding to a previous target frame and perform a black frame insertion operation corresponding to the previous target frame during the target timing process when the driver IC receives a backlight synchronization signal corresponding to the current target frame; the backlight synchronization signal is a signal from a backlight controller for synchronization of the driver IC; An output module, used for outputting a PWM signal corresponding to a current target frame after a black frame insertion operation corresponding to a previous target frame is completed; the PWM signal is used for adjusting the backlight brightness of the target frame; The device also includes: A first determination module is used to determine the frame rate range required for a first target task, and to determine a first intermediate frame rate based on the frame rate range required for the first target task; the first target task is an image display task currently executed based on the control system; the first intermediate frame rate is within the frame rate range required for the first target task; based on the first intermediate frame rate, determine a first initial sending time of a backlight synchronization signal corresponding to each target frame sent by the backlight controller; based on the brightness value of the PWM signal corresponding to the current target frame and the brightness value of the PWM signal corresponding to the previous target frame, adjust the first initial sending time of the backlight synchronization signal corresponding to the current target frame to obtain the first target sending time of the backlight synchronization signal corresponding to the current target frame; based on the first target sending time of the backlight synchronization signal corresponding to the current target frame, send the backlight synchronization signal corresponding to the current target frame to the driver IC through the backlight controller.

8. A backlight control system with variable refresh rate and image black insertion, characterized in that: The system comprises: A memory storing executable program code; a processor coupled to the memory; The processor calls the executable program code stored in the memory to execute the backlight control method with variable refresh rate and image black insertion as described in any one of claims 1-6.

9. A computer storage medium, characterized in that: The computer storage medium stores computer instructions, which, when called, are used to execute the backlight control method with variable refresh rate and image black insertion as described in any one of claims 1-6.

Images