Disclosure of Invention
The application aims to provide a display panel driving method and a display panel capable of improving refreshing of the display panel.
The application discloses a driving method of a display panel, the display panel comprises a plurality of scanning partitions which are sequentially arranged in a column direction, each scanning partition comprises at least one row of pixel units, and the driving method comprises the following steps:
acquiring gray-scale data of each scanning partition of a current frame picture and a next frame picture;
Comparing the gray-scale data acquired in the current frame picture with the gray-scale data acquired in the next frame picture, judging the current scanning partition as a gray-scale data holding area if the gray-scale data are the same, and judging the current scanning partition as a gray-scale data refreshing area if the gray-scale data are different;
When the next frame of picture is scanned and displayed, the gray-scale data of the previous frame is kept to be input into the gray-scale data keeping area, new gray-scale data is generated to the gray-scale data refreshing area, the scanning subareas corresponding to the gray-scale data keeping area are skipped, and the scanning subareas of the gray-scale data refreshing area are directly scanned.
Optionally, each scanning partition includes a row of pixel units, the step of comparing the gray-scale data acquired in the current frame picture and the next frame picture in the current scanning partition, if the gray-scale data are the same, determining that the current scanning partition is a gray-scale data holding area, and if the gray-scale data are different, determining that the current scanning partition is a gray-scale data refreshing area includes:
Comparing the gray-scale data acquired in the current frame picture and the next frame picture by each pixel of the current row pixels, judging the current scanning partition as a gray-scale data holding area if the gray-scale data of each pixel in the current row pixels are the same when the current frame picture and the next frame picture are displayed, and judging the current scanning partition as a gray-scale data refreshing area if the gray-scale data of each pixel in the current row pixels are different when the current frame picture and the next frame picture are displayed.
Optionally, when the next frame of picture is scanned and displayed, the step of keeping the gray-scale data of the previous frame input to the gray-scale data keeping area, generating new gray-scale data to the gray-scale data refreshing area, skipping the scanning partition corresponding to the gray-scale data keeping area, and directly scanning the scanning partition of the gray-scale data refreshing area further comprises the following steps:
Detecting the holding time of the gray-scale data holding area, and if the holding time is longer than the preset time, regenerating all gray-scale data of a new frame of picture for the display of the next frame after the display of the current frame of picture is finished;
And when the refresh rate of each frame is greater than 240Hz, the duration of the preset time is within the duration of 4 frames to 7 frames.
Optionally, the step of detecting the holding time of the gray-scale data holding area, if the holding time is greater than the preset time, and regenerating all gray-scale data of the new frame for displaying the next frame after the display of the current frame is finished includes:
detecting the holding time of the gray-scale data holding area and the scanning line number of the gray-scale data holding area, and if the holding time is longer than the preset time and the scanning line number is longer than the preset line number, regenerating all gray-scale data of a new frame of picture for displaying the next frame after the display of the current frame of picture is finished.
Optionally, comparing the gray-scale data obtained from the current frame and the next frame of each pixel of the current row of pixels, if the gray-scale data of each pixel of the current row of pixels is the same when the current frame and the next frame of pixels are displayed, determining that the current scanning partition is a gray-scale data holding area, if the gray-scale data of each pixel of the current row of pixels is different when the current frame and the next frame of pixels are displayed, determining that the current scanning partition is a gray-scale data refreshing area includes:
Detecting the leakage current value of each sub-pixel in the gray-scale data holding area, calculating the corresponding compensation time, obtaining the maximum value of the compensation time in all pixels, and compensating all pixels of the current row by using the maximum compensation time value.
Optionally, the display panel includes an organic light emitting display panel, a pixel driving circuit is disposed corresponding to each pixel, the pixel driving circuit includes a driving switch, a data input switch and a reset switch, a control end of the driving switch is connected to a first node, an input end of the driving switch is connected to a power supply voltage, an output end of the driving switch is connected to an organic light emitting device, a control end of the data input switch is connected to a scan line, an input end of the driving switch is connected to a data line, an output end of the driving switch is connected to the first node, a control end of the reset switch is connected to a reset line, an input end of the driving switch is connected to a first level signal output end, an output end of the driving switch is connected to the first node, when a next frame of picture is scanned and displayed, a gray-scale data input gray-scale data holding area of a previous frame is held, new gray-scale data is generated to a gray-scale data refreshing area, a scan partition corresponding to the gray-scale data holding area is skipped, and the scan partition of the gray-scale data refreshing area is directly scanned, the steps include:
The lowest potential of the next frame data of the current row of the gray-scale data refreshing area is collected and output to a first level signal output end to be output to a first node; when the potential of the first node is the lowest potential of the next frame data of the current row, the input scanning signal controls the data input switch to be conducted so as to charge the current pixel.
Optionally, when the next frame of picture is scanned and displayed, the step of keeping the gray-scale data of the previous frame input to the gray-scale data keeping area, generating new gray-scale data to the gray-scale data refreshing area, skipping the scanning partition corresponding to the gray-scale data keeping area, and directly scanning the scanning partition of the gray-scale data refreshing area includes:
judging whether the pixels in the current row belong to a first row, if so, outputting an original data voltage value of the current pixel to a first node to control a driving switch to be conducted so as to drive the current pixel when the data input switch is conducted under the control of the input scanning signal; if the pixel is not in the first row, outputting the corresponding data compensation voltage to the first node to control the driving switch to be conducted so as to drive the current pixel.
The application also discloses a display panel driven by the driving method, which comprises a data processor, a logic judging unit, a plurality of criss-cross data lines and scanning lines and a plurality of pixels connected with the data lines and the scanning lines, wherein the data processor analyzes and acquires the gray scale data of each scanning partition of a current frame picture and a next frame picture, the logic judging unit compares the gray scale data acquired in the current frame picture and the next frame picture, and feeds back the comparison result to the data processor to output the corresponding gray scale data to a gray scale data holding area and a gray scale data refreshing area, and controls the corresponding scanning lines to scan.
Optionally, the display panel further includes a refresh rate detection module and a timer, where the refresh rate detection module is configured to detect a refresh rate of each frame of picture, and the timer is configured to count a holding duration of the gray-scale data holding area, detect a holding time of the gray-scale data holding area, and if the holding time is greater than a preset time and the holding time is within the holding time, and the refresh rate of each frame is greater than 240H, regenerate all gray-scale data of a new frame of picture for displaying a next frame after displaying the current frame of picture is completed.
Optionally, the display panel further includes a row judging module and a data compensation voltage generating module, where the row driving module is electrically connected to the data processor and the data compensation voltage generating module, and the row judging module judges whether a pixel in a scanning row in a currently collected gray-scale data refreshing area belongs to a first row, if so, when the input scanning signal controls the data input switch to be turned on, the original data voltage value of the current pixel is output to the first node to control the driving switch to be turned on so as to drive the current pixel; if the pixel is not in the first row, outputting the corresponding data compensation voltage to the first node to control the driving switch to be conducted so as to drive the current pixel.
Compared with the scheme of improving the charging efficiency by improving the response speed of the driving transistor to improve the refresh rate, the application analyzes the display picture information in advance and acquires the gray-scale data of each scanning partition of the current frame picture and the next frame picture; comparing the gray-scale data acquired in the current frame picture with the gray-scale data acquired in the next frame picture, judging the current scanning zone as a gray-scale data holding area if the gray-scale data are the same, judging the current scanning zone as a gray-scale data refreshing area if the gray-scale data are different, finding out data lines with the same content of the two frames through the data difference of the current frame and the next frame, skipping the current line, updating the data of partial lines with the difference, and improving the refreshing rate by the limit of real-time dynamic property and improving the product taste.
Detailed Description
It is to be understood that the terminology used herein, the specific structural and functional details disclosed are merely representative for the purpose of describing particular embodiments, but that the application may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.
The application is described in detail below with reference to the attached drawings and alternative embodiments.
As a first embodiment of the present application, as shown in fig. 1, there is disclosed a driving method of a display panel including a plurality of scan partitions sequentially arranged in a column direction, each of the scan partitions including at least one row of pixel units, the driving method including:
s1: acquiring gray-scale data of each scanning partition of a current frame picture and a next frame picture;
s2: comparing the gray-scale data acquired in the current frame picture with the gray-scale data acquired in the next frame picture, judging the current scanning partition as a gray-scale data holding area if the gray-scale data are the same, and judging the current scanning partition as a gray-scale data refreshing area if the gray-scale data are different;
s3: when the next frame of picture is scanned and displayed, the gray-scale data of the previous frame is kept to be input into the gray-scale data keeping area, new gray-scale data is generated to the gray-scale data refreshing area, the scanning subareas corresponding to the gray-scale data keeping area are skipped, and the scanning subareas of the gray-scale data refreshing area are directly scanned.
Considering that when two frames of images are displayed, the images of partial areas of the two frames are the same, so that the data of the whole frame of images are not required to be changed, the information sources are not changed for a plurality of displayed information sources, and the gray-scale data of each frame are not changed, so that the data which are not changed can be actually updated; for this, in this embodiment, by comparing the gray-scale data of the previous frame and the next frame in the same scanning partition, if the gray-scale data of the current frame and the gray-scale data of the next frame are the same, the gray-scale data holding area is marked, if they are different, the gray-scale data refreshing area is marked, and when the next frame is displayed after the display of the current frame is finished, the scanning partition corresponding to the gray-scale data holding area is skipped directly, and only the scanning partition of the gray-scale data refreshing area is scanned, for example, 1080 lines of scanning lines are taken as an example, and if the previous 120 lines of scanning lines do not need to be scanned, the time of 120 lines of scanning can be reduced, namely, in 1080 lines of display data, the data of the same line is (1 to 120 lines), and then the previous 120 lines do not need to update data. Referring to fig. 2, which shows a schematic diagram of the control signals in this embodiment, a control circuit of 8 scan lines is shown, and it can be seen that b1, b0 are 2bit data, and a control signal of 10bit is required to control 1080 lines; if it is necessary to select the scan from the 8 th row S8, the 2bit data is 11, b1, b0 is 1010, so that the 8 th row scan line, i.e. the control switch on S8 in fig. 2 is turned on, and the scan signal is turned on from the 8 th row. The design mode of the circuit can give 10bit data according to the result of the logic module, thereby controlling the data updating of different rows. After the same data of the same row is skipped, updating the same row and comparing the rows of different data; it should be noted that, if the highest refresh rate supported by the current driving chip is FHD (1920×1080) 240HZ, the data of each row is 1/1080/240=3.85 us. In the data updating period, the scanning time of each row is 3.85us, because 1-120 rows of data are not updated, the required rows are 1080-120=960 rows, the actual refresh rate is 1/(960×3.85) =270 HZ, the refresh rate is improved by reducing the total charging time of one frame, and the refresh rate is changed in real time according to different updated data of each frame, so that the refresh rate can be further improved, and the display effect is improved.
As shown in fig. 3, as a second embodiment of the present application, which is a further refinement and improvement of the above first embodiment, each of the scan partitions includes a row of pixel units, and the step S2 includes:
s231: comparing the gray-scale data acquired in the current frame picture and the next frame picture by each pixel of the current row pixels, judging the current scanning partition as a gray-scale data holding area if the gray-scale data of each pixel in the current row pixels are the same when the current frame picture and the next frame picture are displayed, and judging the current scanning partition as a gray-scale data refreshing area if the gray-scale data of each pixel in the current row pixels are different when the current frame picture and the next frame picture are displayed.
In order to improve the control precision, the final display of the picture is more uniform, each scanning partition only comprises one row of pixel units, when gray scale data comparison is carried out, gray scale data of each pixel in each row of pixels in the current frame and gray scale data of the next frame need to be compared, if one pixel in one row is different, the gray scale data refresh area is judged, and after the display of the current frame is finished, the corresponding gray scale data is regenerated to drive, so that the picture display corresponding to each pixel is controlled more finely.
Further, the step S231 further includes the following steps:
s232: detecting the leakage current value of each sub-pixel in the gray-scale data holding area, calculating the corresponding compensation time, obtaining the maximum value of the compensation time in all pixels, and compensating all pixels of the current row by using the maximum compensation time value.
The area part which is not refreshed, namely the gray level data holding area, saves the charging time compared with other refreshing area parts, but the influence of leakage current is more obvious, so that the area part which keeps the data unchanged has brightness difference with other data, namely the brightness of the display panel in the area can be influenced by the leakage current for a long time, and the display panel has the problem of uneven display.
In this regard, the problem of leakage current cannot be ignored for the data holding area, and the leakage current is compensated for this area, and the embodiment also compensates for each sub-pixel in the gray scale data holding area, thereby solving the problem of refresh rate and maintaining the uniformity of panel display.
Taking the current display panel as an organic light-emitting display panel as an example, referring to fig. 4, the display panel comprises an organic light-emitting display panel, a pixel driving circuit is arranged corresponding to each pixel, the pixel driving circuit comprises a driving switch and a data input switch, the control end of the driving switch is connected with a first node A, the input end of the driving switch is connected with a power supply voltage VDD through a second node B, the output end of the driving switch is connected with an organic light-emitting device, the control end of the data input switch is connected with a scanning line, the input end of the data input switch is connected with a data line, and the output end of the data input switch is connected with the first node; m1 and M2 are TFT elements, C1 bit storage capacitor, VDD is constant current source, OLED is light emitting diode, sn is scanning line or scanning signal, dm is data line or data signal. The working principle is that a t1 time line scanning circuit is turned on, M2 is turned on, a pixel driving signal is input, M1 is turned on, a pixel signal is written into C1, the t2 time scanning signal is turned off, the C1 voltage keeps M1 on, VDD continuously provides current for OLED, and the current flowing through the OLED is controlled by an M1 transistor.
When the next frame data in the area is detected to be the same as the data in the frame, the C1 is not required to be recharged, but the VA voltage must be lower than the required data voltage Vdata due to the leakage current, and each sub-pixel in a row needs to be recharged. Normally, the scan line Sn of each row has the same open time, i.e., the scan time, Δq is the charge amount of C1, Δv is the voltage difference of C1, I is the charging current, Δt is the charging time, vlon is the voltage difference from the ideal Vdata due to the leakage current, Δq=c=Δv=i×Δt, C is the charge amount, Δv=i×Δt/C is a constant value, since Δv is the voltage difference across C1, one end of C1 is VDD is a constant value, and the other end is VA, vdata-vdd= Δv=i×Δt/C is vdata=vdd+ (i×Δt/C), but the leakage current is Vdata-v=vdd+ (i×Δt/C), and Δv= (Vdata-V drain) ×vdd/C) is a small voltage difference, which is a long time required for charging. However, for the magnitude of the leakage current, each sub-pixel is different, resulting in different magnitude of the vleakage, and for the calculation of vleakage, there are many existing schemes, which are not specifically described herein. The time Deltat for compensating the V leakage of each sub-pixel in a row is different, and the maximum time Deltat (max) is selected as the minimum compensation leakage current charging time of the row. This time is also much less than the normal charge time per row, and can also serve to reduce the total refresh time of one frame, thereby increasing the overall refresh rate.
Further, the pixel driving circuit for the gray-scale data refresh area is also changed, and the step S3 further includes the steps of:
S331: the lowest potential of the next frame data of the current row of the gray-scale data refreshing area is collected and output to a first level signal output end to be output to a first node; when the potential of the first node is the lowest potential of the next frame data of the current row, the input scanning signal controls the data input switch to be conducted so as to charge the current pixel.
Specifically, for the data refresh area, there is a problem that recharging is equivalent to recharging this area, generally, for each row of charging, the voltage of VA will be pulled below the lowest data voltage first, so that the voltage Reset of VA can be further included in the pixel driving circuit, the control end of the Reset switch is connected to the Reset line, the input end of the Reset switch is connected to the first level signal output end, and the output end is connected to the first node, as shown in fig. 5, the change trend of VGS and IDS of M1 is kept consistent, so that hysteresis effect (VGS is changed from large to small and IDS is different and causes display difference) is avoided, but recharging is equivalent to recharging the data voltage of the target by Vreset, so that on one hand, power consumption is increased, and on the other hand, scanning time is long. In this regard, for the change of the gray-scale data holding area and the gray-scale data refreshing area in the scanning partition, as shown in fig. 6, M1 and M2 are TFT elements, C1 bit storage capacitor, VDD is constant current source, OLED is light emitting diode, sn is scanning signal, dm is data signal, and in the pixel driving circuit in the gray-scale data holding area, reset switch M3 is kept turned off, M1 and M2 are turned on, and charge and light emission are performed to OLED, so as to realize electric leakage and charge; in a pixel driving circuit in a gray level data refreshing area, before charging, analyzing the difference between the frame data and the next frame data, if the difference is to be updated, acquiring the lowest voltage of the next frame data of the line to be supplied to Vmin, then opening a Reset signal before charging, enabling M2 to be disconnected, enabling M1 to be connected, pulling all voltages of the line to Vmin so as to avoid hysteresis effect, then stopping inputting the Reset signal, enabling M3 to be disconnected, opening a scanning signal of the current line, controlling M2 to be connected, keeping M1 to be connected at the same time, and carrying out supplementary charging on each sub-pixel of the line, wherein the maximum charging time of the line is determined by one sub-pixel with the largest voltage difference, and Deltat (max) = (Vdata (max) -VDD-Vmin) & lt/I is the maximum charging time of the line, so that the charging time of the data refreshing area can be saved; the display time of the final one frame is Δt= Δt (data holding area t1+t2+tn) +Δt (data refresh area tm+t (m+1) +t (m+x)).
As shown in fig. 7, as a third embodiment of the present application, the first embodiment or the second embodiment is further refined and perfected, in the above embodiment, by analyzing the data of the current frame and the next frame, adjusting the algorithm of each line of each frame in real time, and dynamically adjusting the refresh rate, the limitation of the refresh rate caused by the limitation of the IC transmission rate can be broken through, and the refresh rate is improved to the greatest extent. The power consumption can be saved, and the method is more suitable for the application of high-brush products, and in the embodiment, the method further comprises the following steps after the step S3:
s4: detecting the holding time of the gray-scale data holding area, and if the holding time is longer than the preset time, regenerating all gray-scale data of a new frame of picture for the display of the next frame after the display of the current frame of picture is finished;
And when the refresh rate of each frame is greater than 240Hz, the duration of the preset time is within the duration of 4 frames to 7 frames.
Further, except that the holding time is used as a condition for triggering generation of the next frame data signal, the number of scanning lines in the gray level data holding area is used as a trigger for adjustment, specifically, the holding time of the gray level data holding area and the scanning line number of the gray level data holding area are detected, and if the holding time is longer than the preset time and the scanning line number is longer than the preset line number, all gray level data of a new frame picture are regenerated for display of the next frame after the display of the current frame picture is finished; that is, a new frame of data is regenerated, not only the time problem is considered, but also the number of lines is considered, and a new frame of data can be regenerated with a plurality of lines, and the number of lines is less, or all data of a whole frame can be generated.
As shown in fig. 8, as a fourth embodiment of the present application, the above second embodiment is further refined and perfected, considering that each pixel driving circuit in the organic light emitting display panel needs to be connected to a power supply voltage through a power supply line, except for the first row of pixels, each row of pixels is affected by the current of the previous row of pixels due to the presence of a line resistance, and the step S3 includes:
s381: judging whether the pixels in the current row belong to a first row, if so, outputting an original data voltage value of the current pixel to a first node to control a driving switch to be conducted so as to drive the current pixel when the data input switch is conducted under the control of the input scanning signal; if the pixel is not in the first row, outputting the corresponding data compensation voltage to the first node to control the driving switch to be conducted so as to drive the current pixel.
The data compensation voltage is calculated by the following formula ①-③:
……①
……②
……③
Wherein,The data compensation voltage after the compensation for the N-th row of pixels, R is the equivalent resistance of the power supply line corresponding to each row of pixels,An ideal drive current value for the 1 st row of pixels,An ideal driving current value for the nth row pixels; Is the power supply voltage value,In order to drive the tube voltage threshold value,The original data voltage of the pixel in the N line is that A is a constant, and N is a natural number greater than or equal to 2.
When the data voltage compensation is carried out on the pixels in the current row, only whether the current pixels belong to the first row is judged, if so, the original data voltage value of the current pixels is output to the grid end of the driving tube to drive the current pixels; if the pixel is not in the first row, outputting a corresponding data compensation voltage to the gate end of the driving tube to drive the current pixel, and compensating the current row of pixels according to the data compensation voltage, so that the luminous current of the current row is changed, and the uneven brightness of the display panel is improved.
As shown in fig. 9, as a fifth embodiment of the present application, a display panel 100 is disclosed, the display panel 100 is driven by using the driving method according to any of the above embodiments, the display panel 100 includes a data processor 110, a logic judging unit 120, a plurality of crisscrossed data lines 140 and scan lines Sn, and a plurality of pixels 150 connected to the data lines 140 and the scan lines Sn, the data processor 110 analyzes and acquires gray-scale data of each scan partition of a current frame picture and a next frame picture, the logic judging unit 120 compares the gray-scale data acquired in the current frame picture and the next frame picture, and feeds back the comparison result to the data processor 110 to output the corresponding gray-scale data to a gray-scale data holding area and a gray-scale data refreshing area, and controls the corresponding scan lines Sn to scan.
Further, the display panel 100 further includes a refresh rate detection module 160 and a timer 170, where the refresh rate detection module 160 is configured to detect a refresh rate of each frame, and the timer 170 is configured to count a holding duration of the gray data holding area, detect a holding time of the gray data holding area, and if the holding time is greater than a preset time and the refresh rate of each frame is greater than 240H in the holding time, regenerate all gray data of a new frame for displaying a next frame after displaying the current frame.
In addition, the display panel 100 further includes a row determining module 180 and a data compensation voltage generating module 190, where the row driving module is electrically connected to the data processor 110 and the data compensation voltage generating module 190, and the row determining module 180 determines whether the pixels 150 in the scan row in the currently collected gray-scale data refresh area belong to the first row, if so, when the input scan signal controls the data input switch to be turned on, the original data voltage value of the current pixel 150 is output to the first node to control the driving switch to be turned on so as to drive the current pixel 150; if the pixel is not the first row, the corresponding data compensation voltage is output to the first node to control the driving switch to turn on and drive the current pixel 150.
It should be noted that, the limitation of each step in the present solution is not to be considered as limiting the sequence of steps on the premise of not affecting the implementation of the specific solution, that is, the steps written in the previous step may be executed before, or executed after, or even executed simultaneously, so long as the implementation of the present solution is possible, all the steps should be considered as falling within the protection scope of the present application. The inventive concept of the present application can form a very large number of embodiments, but the application documents are limited in size and cannot be listed one by one, so that on the premise of no conflict, the above-described embodiments or technical features can be arbitrarily combined to form new embodiments, and after the embodiments or technical features are combined, the original technical effects can be enhanced.
The above description of the application in connection with specific alternative embodiments is further detailed and it is not intended that the application be limited to the specific embodiments disclosed. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the application, and these should be considered to be within the scope of the application.