CN117153112A - Driving method and device of local dimming display - Google Patents
Driving method and device of local dimming display Download PDFInfo
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
- G09G2330/02—Details of power systems and of start or stop of display operation
- G09G2330/021—Power management, e.g. power saving
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Abstract
The application provides a driving method of a local dimming display, which is characterized by comprising the following steps: s1, selecting a backlight extraction method and a liquid crystal pixel compensation method through analog simulation, and storing the backlight extraction method and the liquid crystal pixel compensation method in a hardware language description mode into a driver; s2: the received HDMI video signals are stored in the designated frame buffer address of DDR3 by driving, and on one hand, the received HDMI video signals are stored in the designated frame buffer address of DDR3, and are transmitted to a driving IC of backlight in a liquid crystal display after being extracted by the backlight to lighten different partitions; on the other hand, the signals obtained after the backlight signals are subjected to pixel compensation are transmitted to an IC (integrated circuit) of a liquid crystal layer in the liquid crystal display so as to display pictures. The built-in backlight extraction algorithm and the pixel compensation method select the optimal combination mode of several target objects through simulation of a plurality of scenes, so that the display quality and the power consumption of the whole picture are improved, and the phenomena of halation, exposure and pixel distortion possibly occurring in the current area dimming display are improved.
Description
Technical Field
The application relates to the technical field of liquid crystal display, in particular to a driving method and a driving device of a local dimming display.
Background
In existing practical product applications, LCDs with mini-LED zone control backlights have not been popular. Taking the application of this display device in vehicles as an example, differences from the general display device in research and development content are mainly focused on these several places: development of a backlight driving chip, design of a backlight control circuit, and development of a central control chip for receiving an upper computer signal and synchronizing backlight with a liquid crystal picture. At present, the parts are developed by different manufacturers, and the defects and difficulties have the following points: 1. the functions of different backlight chips and the built-in registers have great difference, so that the design period of a backlight control circuit is long, and when the central control chip controls different backlight chips, the EEPROM with corresponding programs is needed to be externally hung and burnt to interconnect the two chips, so that the design period is also increased; 2. the interconnection between too many chips causes signal loss and limitation of transmission rate, which is disadvantageous for researching a display device with higher pixel number and higher refresh rate, because the limitation of hardware firstly restricts the exertion of software in further research; 3. the biggest difference between partition dimming and global dimming is that the brightness of the individual lamp beads is controlled, and for different backlight intensities, if the signals transmitted to the liquid crystal are the same as the original signals, the display effect of the picture is uneven, so that the algorithm of backlight brightness extraction and liquid crystal pixel compensation needs to be studied.
Disclosure of Invention
In order to solve the above technical problem, according to a first aspect of the present disclosure, the present application provides a driving method of a local dimming display, including:
s1, selecting a backlight extraction method and a liquid crystal pixel compensation method through analog simulation and storing the backlight extraction method and the liquid crystal pixel compensation method into a driver, wherein the method specifically comprises the following steps of: the method comprises the steps of carrying out a first treatment on the surface of the
S101, constructing a gallery, and selecting four typical representative pictures from the gallery;
s102, carrying out grey processing on the picture, and dividing the processed picture into backlight pictures corresponding to the actual partition number of the backlight by a backlight extraction method;
s103, sleeving the backlight picture into a diffusion template to obtain a diffused backlight picture;
s104, compensating the backlight picture serving as a pixel compensation reference, and superposing the backlight picture with the diffused backlight picture to obtain an output picture;
s105: determining a backlight extraction method and a liquid crystal pixel compensation method by adopting a method combining objective evaluation and subjective evaluation;
s2: the received HDMI video signal is stored in a designated frame buffer address of DDR3 by a driver, and on one hand, the received HDMI video signal is extracted by backlight and then transmitted to a backlight driving IC in a liquid crystal display to lighten different partitions; on the other hand, the signals obtained after the backlight signals are subjected to pixel compensation are transmitted to an IC (integrated circuit) of a liquid crystal layer in the liquid crystal display so as to display pictures.
Specifically, step S101 specifically includes: four pictures with typical representation are selected by taking the contrast and average brightness as the standard, and the pictures respectively represent high brightness and high contrast, high brightness and low contrast, low brightness and high contrast and low brightness and low contrast.
The technical scheme has simpler structure, and the embedded algorithm performs pixel compensation on the liquid crystal layer picture, thereby improving the problems in the background technology.
Specifically, step S102 specifically includes: converting the picture into a gray picture, and dividing the gray picture into m x n areas with different sizes corresponding to the number of backlight partitions, wherein m and n are constants, and the values of m and n are the same as the number of the backlight partitions.
Through the technical scheme, after the picture is subjected to graying treatment, the picture is divided into m x n small areas corresponding to the backlight partition number, so that m x n backlight pictures are obtained.
Specifically, step S103 further includes: and extracting a plurality of pixel points in each region of the gray level picture by using different backlight extraction methods to obtain a unique gray level value, wherein the gray level value is the brightness of each lamp bead.
Specifically, step S103 further includes: calculating the brightness coefficient of the diffusion of the brightness of the lamp beads to the target direction; the target direction includes: a center direction, an upward and downward direction, a left and right direction and an oblique square four-corner direction; the luminance coefficient includes: a center-direction residual luminance coefficient a, an upward-downward-direction diffusion luminance coefficient b, a leftward-rightward-direction diffusion luminance coefficient c, and an oblique-square-direction diffusion luminance coefficient d.
Specifically, step S103 further includes: sleeving the backlight picture into the diffusion template; the diffusion template is V _out_e_f ＝a*V _out_e_f +b*(V _out_e-1_f +V _out_e+1_f )+c*(V _out_e_f-1 +V _out_e_f+1 )+d*(V _out_e-1_f-1 +V _out_e+1_f-1 +V _out_e-1_f+1 +V _out_e+1_f+1 ) Wherein e is the number of lines of the backlight pictures sleeved in the diffusion template, e is 0 < e < m, e is an integer, f is the number of columns of the backlight pictures sleeved in the diffusion template, f is 0 < f < n, f is an integer, V _out_e_f The gray value of the backlight picture sleeved in the diffusion template.
Specifically, step S103 further includes: and (3) expanding the backlight picture sleeved in the diffusion template into a gray level picture consistent with the picture by using a linear diffusion method.
According to a second aspect of the present disclosure, the present application provides a driving apparatus of a local dimming display, comprising: comprising the following steps:
an HDMI input decoding module configured to transmit digitized audio and video signals;
an HDMI output encoding module configured to transmit digitized audio and video signals;
the VDMA frame buffer module is configured for multi-frame buffer to prevent picture tearing and adapt to different input and output pixel clocks;
the video_timing_controller Video timing control module is configured to generate timing information of Video output with any resolution;
the DDR3 control module is configured to store video frames and software control codes;
the backlight partition dimming module is configured to write a backlight extraction method and a liquid crystal pixel compensation method selected by simulation into an actual circuit in a hardware language form; the backlight partition dimming module receives a frame of picture transmitted from the VDMA frame buffer module and converts the picture into a gray value form; on one hand, generating data required for driving a backlight IC, and dividing a picture into gray scale picture values corresponding to the sizes of backlight partitions by using a backlight extraction algorithm module; and then the numerical value is transmitted into a backlight data coding module, and is coded and transmitted according to the channels and SPI time sequence rules corresponding to different chips. On the other hand, generating data required by sending the data to the liquid crystal IC, extracting the backlight data obtained in the last step, performing pixel compensation on the backlight data and the frame data extracted from the VDMA frame buffer module, and sending the obtained data to the HDMI output coding module.
Specifically, the backlight partition dimming module further includes:
and a pixel compensation module. The method comprises the steps of configuring the video frame image subjected to partitioning to compensate;
a pixel partitioning module configured to partition a received video frame;
and the backlight extraction algorithm module is configured for storing and executing a backlight extraction method and a liquid crystal pixel compensation method.
Specifically, the HDMI output encoding module, the HDMI input decoding module, the backlight partition dimming module, the DDR3 video frame buffer and reading module and the VDMA video display module are integrated on the same integrated circuit board.
The application provides a driving method and a driving device for regional dimming, which have the following beneficial effects:
the built-in backlight extraction algorithm and the pixel compensation method select several combination modes through the simulation of a plurality of scenes, then put into an actual circuit for testing, select the optimal combination mode in a target object, improve the display quality and the power consumption of the whole picture, and improve the phenomena of halation, exposure, image capture and pixel distortion possibly occurring in the current area dimming display to a certain extent.
All algorithms and image transmission processing flows are integrated into one ZYNQ chip, and compared with the problems of non-uniform transmission speed, asynchronous transmission signals and the like caused by using a plurality of chips in the traditional architecture, the method has the advantage that the problems of non-synchronization of transmission signals and the like are greatly improved. And the inside of the ZYNQ chip is provided with a fast and unified AXI4 bus for unified interconnection communication, so that the image processing speed of the new architecture can meet the follow-up higher-speed interface adaptation. Meanwhile, all driving modes and signal processing flows are modularized, and compared with the prior special chips which have different roles, the device has better expansibility and suitability, and devices of the corresponding part can be adapted only by changing a driving code in one control module.
Drawings
The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the application. Many of the intended advantages of other embodiments and embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
FIG. 1 is a flow chart providing a method of simulation determination backlight extraction and pixel compensation in accordance with one embodiment of the present application;
FIG. 2 is a flow chart providing image signal processing and algorithm embedding according to one embodiment of the present application;
FIG. 3 is a block diagram providing a display device driving structure according to one embodiment of the present application;
FIG. 4 is a block diagram of a circuit configuration of a display device according to an embodiment of the present application;
fig. 5 is a circuit connection diagram of a backlight driving chip according to an embodiment of the present application.
Detailed Description
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the application may be practiced. For this, directional terms, such as "top", "bottom", "left", "right", "upper", "lower", and the like, are used with reference to the orientation of the described figures. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims.
The present application provides a driving method of a local dimming display, fig. 1 is a flowchart for providing a simulation determination backlight extraction and pixel compensation method according to an embodiment of the present application, as shown in fig. 1, including:
s1, selecting a backlight extraction method and a liquid crystal pixel compensation method through analog simulation and storing the backlight extraction method and the liquid crystal pixel compensation method into a driver, wherein the method specifically comprises the following steps of: the method comprises the steps of carrying out a first treatment on the surface of the
S101, constructing a gallery, and selecting four typical representative pictures from the gallery;
s102, carrying out grey processing on the picture, and dividing the processed picture into backlight pictures corresponding to the actual partition number of the backlight by a backlight extraction method;
s103, sleeving the backlight picture into a diffusion template to obtain a diffused backlight picture;
s104, compensating the backlight picture serving as a pixel compensation reference, and superposing the backlight picture with the diffused backlight picture to obtain an output picture;
s105: determining a backlight extraction method and a liquid crystal pixel compensation method by adopting a method combining objective evaluation and subjective evaluation;
s2: and storing the received HDMI video signals into the designated frames of DDR3 frame by the driver, obtaining an output picture by a backlight extraction method and a liquid crystal pixel compensation method stored in the driver, and transmitting the output picture to an IC of the liquid crystal display through an HDMI interface.
In a specific embodiment, firstly, selecting four representative typical pictures from a picture library according to two indexes of contrast and average brightness; converting the four pictures into gray pictures, and dividing the gray pictures into areas with different sizes corresponding to the number of backlight partitions, wherein the areas are assumed to be m x n areas; and then, extracting a plurality of pixel points in each cell by adopting different backlight extraction methods to obtain a unique gray value, wherein the gray value is the brightness of each lamp bead in the cell.
Further, the gray scale picture after the lamp beads pass through the diffusion plate is simulated by calculating the outward diffusion of the brightness of the lamp beads for a plurality of times, wherein the diffusion direction is upward and downward diffusion, leftward and rightward diffusion and diagonal four corners diffusion, meanwhile, the center residual brightness coefficient is set to be a, the upward and downward diffusion brightness is set to be b, the leftward and rightward diffusion brightness is set to be b, and the diagonal four corners diffusion brightness is set to be d. The method for measuring the a, b, c, d four coefficients comprises the following steps: the brightness is obtained by comparing the actual brightness corresponding to each direction with the extracted unique gray value.
After a, b, c, d data are obtained, the backlight picture with the size of m x n is outwards expanded for one circle, so that each area can be sleeved in the diffusion template, and the size of the expanded backlight picture is (m+2) x (n+2).
Taking the e-th row and f-th column backlight pictures as examples, the gray value before diffusion is known as V _in_e_f The gray value V after diffusion is calculated by sleeving a diffusion template _out_e_f I.e.
And then the diffused backlight picture is diffused again by using linear diffusion, at the moment, the diffused backlight picture with the size of m x n can be directly expanded to the diffused backlight picture with the size of (2 m) x (2 n), and the step is repeated for 6 times.
After the steps are carried out for 6 times, the backlight picture is expanded to a gray picture with the same size as the original input picture, and at the moment, pixel compensation is carried out on the original input picture according to the diffused backlight picture; and superposing the compensated picture with the backlight picture subjected to multiple diffusion to obtain an output picture.
It should be noted that, in the above steps, what kind of backlight extraction method and liquid crystal pixel compensation method are adopted may be determined by a method of combining objective evaluation with subjective evaluation, and multiple combination manners may be determined for different application scenarios.
Fig. 2 is a flowchart of providing image signal processing and algorithm embedding according to an embodiment of the present application, as shown in fig. 2, in an actual driving, an HDMI video signal received by the peripheral circuit is captured by the VDMA module and stored at a specified address of the DDR3 in a multi-frame buffer manner.
Taking this actual operation as an example, the resolution of the display used is 1920×720, the partition number of the backlight module is 26×10, and the refresh rate is 60 HZ. The data of one frame of image is stored in the format of RGB888, and the backlight needs gray value data, which needs to be converted first, and then the format of the data storage exists in a row-by-row form, which is unfavorable for data processing, and directly storing such large data consumes many logic resources, and it becomes difficult to send the data to the backlight IC later.
It is known through calculation that 1920 pixels in each row cannot be in one-to-one correspondence with 26 lamps in one row of the backlight, so that some pixels can be discarded in a counter manner. In the processing of one row, the backlight pixel extraction algorithm is sleeved on each 73 data, 26 times of execution of the operation are accumulated to convert one row of 1920 data into 26 gray value data, the processing is carried out on each row, the obtained array is 26 x 720 decimal numbers ranging from 0 to 255, the occupation rate of register resources can be reduced by storing the group data, then a backlight extraction formula is sleeved, 26 x 10 data corresponding to the backlight are obtained, and the data are ready to be sent to an IC in the backlight through the SPI controller. Meanwhile, the original input picture and the backlight data set are sleeved into a pixel compensation formula and are sent to an IC in the liquid crystal display through an HDMI interface.
Another aspect of the present application provides a driving apparatus for a local dimming display, comprising:
an HDMI input decoding module configured to transmit digitized audio and video signals;
an HDMI output encoding module configured to transmit digitized audio and video signals;
the VDMA video display module is configured to realize video output display with any resolution;
the DDR3 video frame buffering and reading module is configured to store and read video frames;
the backlight partition dimming module is configured to select a backlight extraction method and a liquid crystal pixel compensation method through analog simulation; specifically, a gallery is constructed, and four typical representative pictures are selected from the gallery; the picture is subjected to gray-scale treatment, and the treated picture is divided into backlight pictures corresponding to the actual number of partitions of the backlight by a backlight extraction method; sleeving the backlight picture into a diffusion template to obtain a diffused backlight picture; the picture is compensated by taking the backlight picture as a pixel compensation reference, and is overlapped with the diffused backlight picture to obtain an output picture; determining a backlight extraction method and a liquid crystal pixel compensation method by adopting a method combining objective evaluation and subjective evaluation; receiving the video frames stored in the DDR3 video frame buffer and reading module, obtaining an output picture through a backlight extraction method and a liquid crystal pixel compensation method, and sending the output picture to the HDMI output coding module.
The backlight partition dimming module further comprises:
and a pixel compensation module. The method comprises the steps of configuring the video frame image subjected to partitioning to compensate;
a pixel partitioning module configured to partition a received video frame;
and the backlight extraction algorithm module is configured for storing and executing a backlight extraction method and a liquid crystal pixel compensation method.
Fig. 3 is a block diagram showing a driving structure of a display device according to an embodiment of the present application, fig. 4 is a block diagram showing a circuit structure of a display device according to an embodiment of the present application, and fig. 5 is a circuit connection diagram showing a backlight driving chip according to an embodiment of the present application; as shown in fig. 3 to 5, first, in the configuration of the EEPROM, the PC as a video input terminal reads EDID data of the display device through IIC buses of the HDMI interface 15 to 16 pins to transmit a proper resolution. The selected EEPROM model is AT24C02 with the size of 256 Bytes, and just can store complete EDID data. The standard IIC protocol is configured using IIC controller 1 at zynq_ps end with a clock of 400kHZ.
Secondly, the control of an input end HDMI decoding chip SIL9013 and an output end HDMI encoding chip SIL9134 supports the highest 1080P@60HZ video transmission, the two chips select the same IIC bus transmission instruction, and an IIC controller 2 at a ZYNQ_PS end is used for configuring a standard IIC protocol, and the clock is 400kHZ. The two chips are configured by default registers, the input end decoding chip converts TMDS level signal data transmitted from the HDMI input interface into 24-bit parallel RGB data, line field synchronous signals and other control signals, and the output end encoding chip converts the RGB data and the control signals into three paths of TMDS signals again and transmits the three paths of TMDS signals to 1-9 pins of the HDMI output interface.
Then the configuration of the ZYNQ development board is realized, and the core idea is to use a soft core logic circuit of the FPGA to receive signals, store the signals and process the signals. In the embodiment, an AXI4 protocol is used for communication between PL and PS end in ZYNQ, wherein the AXI4_lite protocol is simple, occupies less resources at low speed, and is used for instruction communication in address mapping; the axi4_stream protocol occupies a lot of resources at high speed and is commonly used for big data storage. All the soft cores are connected with an AXI_GP interface of ZYNQ_PS through an AXI4_lite bus in the FPGA, and receive configuration information from a PS end core ARMMCU. The RGB signals and control signals decoded by SIL9013 are transmitted into a video_in module in the FPGA. The video_in module transmits control signals to the video_timing_controller module for storage, and converts 24-bit parallel RGB data signals into 24-bit AXI4_stream signals for transmission to the VDMA_in module. The vdma_in module processes the transmitted signal into fewer bit widths: 16 bits, and stores one or more frames of pixel data into DDR3 designated addresses through an AXI_HP interface of a PS end.
Next, the generation of the synchronization signal is awaited, where the data stream is split into two directions, one for controlling the liquid crystal display portion of the display device and the other for controlling the backlight partition modulation of the display device. In a first aspect, the vdma_out module reads pixel data of bit width 16 from the DDR3 specified frame and processes the data into 24-bit axi4_stream format for transmission to the video_out module. At the same time, the video_timing_controller module generates timing information required by an output terminal and transmits the timing information to the video_out module. The video_out module processes the data into pixel data RGB [23:0], the control signal is transmitted to the HDMI output coding chip, and the pixel data RGB is converted into TMDS signals after being coded and transmitted to a liquid crystal display picture of the display device through the HDMI output interface. On the other hand, the data of the same frame of picture in the DDR3 designated address is transmitted to a backlight partition chip of the display device through the SPI controller after being subjected to image processing.
And finally, the circuit connection of the backlight partition dimming chip is realized. Firstly, the chip selects MAX25500, 4 column scanning channels and 24 row scanning channels are provided, and 96 dimming partitions can be regulated and controlled under full load. For 26 x 10 partitions in this embodiment, three backlight partition dimming chips are used, the connection between the chips adopts a daisy chain form, that is, the SDI end of the SPI controller at the ZYNQ end is only connected to the SDI interface of the first chip, the SDO interface of the chip is connected to the SDI interface of the next chip, and so on, the SDO interface of the last chip returns to the SPI controller of the ZYNQ to complete the complete SPI timing sequence. The chip and the LEDs are interconnected in a common anode mode, the anode of each LED is connected with the row scanning channel and the power supply, the cathode of each LED is connected with the row scanning channel and the ground, and the actual current value of each LED in each partition is controlled by a signal transmitted by the SPI controller.
It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present application without departing from the spirit and scope of the application. In this manner, the application is also intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents. The word "comprising" does not exclude the presence of other elements or steps than those listed in a claim. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.
Claims (10)
1. A driving method of a local dimming display, comprising:
s1, selecting a backlight extraction method and a liquid crystal pixel compensation method through analog simulation and storing the backlight extraction method and the liquid crystal pixel compensation method into a driver, wherein the method specifically comprises the following steps of:
s101, constructing a gallery, and selecting four typical representative pictures from the gallery;
s102, carrying out gray processing on the picture, and dividing the processed picture into backlight pictures corresponding to the actual partition number of the backlight by a backlight extraction method;
s103, sleeving the backlight picture into a diffusion template to obtain a diffused backlight picture;
s104, the picture is compensated by taking the backlight picture as a pixel compensation reference and is overlapped with the diffused backlight picture to obtain an output picture;
s105: the backlight extraction method and the liquid crystal pixel compensation method;
s2: the received HDMI video signal is stored in a designated frame buffer address of DDR3 by a driver, and on one hand, the received HDMI video signal is extracted by backlight and then transmitted to a backlight driving IC in a liquid crystal display to lighten different partitions; on the other hand, the signals obtained after the backlight signals are subjected to pixel compensation are transmitted to an IC (integrated circuit) of a liquid crystal layer in the liquid crystal display so as to display pictures.
2. The method for driving a local dimming display according to claim 1, wherein the step S101 specifically comprises: four representative pictures are selected with the contrast and average brightness as the standard, and represent high-brightness high-contrast, high-brightness low-contrast, low-brightness high-contrast and low-brightness low-contrast respectively.
3. The method for driving a local dimming display according to claim 1, wherein the step S102 specifically comprises: converting the picture into a gray picture, and dividing the gray picture into m x n areas with different sizes corresponding to the number of backlight partitions, wherein m and n are constants, and the values of m and n are the same as the number of the backlight partitions.
4. A method of driving a local dimming display as claimed in claim 3, wherein step S103 further comprises: and extracting a plurality of pixel points in each region of the gray-scale picture by using different backlight extraction methods to obtain a unique gray-scale value, wherein the gray-scale value is the brightness of each lamp bead.
5. A method of driving a local dimming display as claimed in claim 3, wherein step S103 further comprises: calculating the brightness coefficient of the diffusion of the brightness of the lamp beads to the target direction; the target direction includes: a center direction, an upward and downward direction, a left and right direction and an oblique square four-corner direction; the luminance coefficient includes: a center-direction residual luminance coefficient a, an upward-downward-direction diffusion luminance coefficient b, a leftward-rightward-direction diffusion luminance coefficient c, and an oblique-square-direction diffusion luminance coefficient d.
6. The method for driving a local dimming display as claimed in claim 5, wherein the step S103 further comprises: sleeving the backlight picture into the diffusion template; the diffusion template is as follows:
wherein e is the number of lines of the backlight picture sleeved in the diffusion template, e is 0 < m, e is an integer, f is the number of columns of the backlight picture sleeved in the diffusion template, f is 0 < n, f is an integer, V _out_e_f And the gray value of the backlight picture is sleeved in the diffusion template.
7. The method for driving a local dimming display as claimed in claim 1, wherein the step S103 further comprises: and expanding the backlight picture sleeved in the diffusion template into a gray level picture consistent with the picture by using a linear diffusion method.
8. A driving apparatus for a local dimming display, comprising:
an HDMI input decoding module configured to transmit digitized audio and video signals;
an HDMI output encoding module configured to transmit digitized audio and video signals;
the VDMA frame buffer module is configured for multi-frame buffer to prevent picture tearing and adapt to different input and output pixel clocks;
the video_timing_controller Video timing control module is configured to generate timing information of Video output with any resolution;
the DDR3 control module is configured to store video frames and software control codes;
the backlight partition dimming module is configured to write a backlight extraction method and a liquid crystal pixel compensation method selected by simulation into an actual circuit in a hardware language form; the backlight partition dimming module receives a frame of picture transmitted from the VDMA frame buffer module and converts the picture into a gray value form; on one hand, generating data required for driving a backlight IC, and dividing a picture into gray scale picture values corresponding to the sizes of backlight partitions by using a backlight extraction algorithm module; and then the numerical value is transmitted into a backlight data coding module, and is coded and transmitted according to the channels and SPI time sequence rules corresponding to different chips. On the other hand, generating data required by sending the data to the liquid crystal IC, extracting the backlight data obtained in the last step, performing pixel compensation on the backlight data and the frame data extracted from the VDMA frame buffer module, and sending the obtained data to the HDMI output coding module.
9. The driving apparatus for a local dimming display as claimed in claim 8, wherein the backlight partition dimming module further comprises:
the pixel compensation module is configured to compensate the partitioned video frame image;
a pixel partitioning module configured to partition a received video frame;
and the backlight extraction algorithm module is configured for storing and executing the backlight extraction method and the liquid crystal pixel compensation method.
And the backlight data coding module is configured to package the processed data into backlight signals suitable for corresponding backlight driving ICs.
10. The driving device for a local dimming display according to claim 8, wherein the HDMI output encoding module, the HDMI input decoding module, the backlight partition dimming module, the video_timing_controller Video timing control module, the DDR3 control module and the VDMA frame buffer module are integrated on the same integrated circuit board.
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| CN117373397A (en) * | 2023-12-07 | 2024-01-09 | 深圳市欧冠微电子科技有限公司 | Screen brightness adjusting method and device, electronic equipment and storage medium |
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| CN117373397B (en) * | 2023-12-07 | 2024-02-23 | 深圳市欧冠微电子科技有限公司 | Screen brightness adjusting method and device, electronic equipment and storage medium |
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