CN114822342A - Gamma debugging method and device for display panel - Google Patents

Gamma debugging method and device for display panel Download PDF

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Publication number
CN114822342A
CN114822342A CN202110126126.3A CN202110126126A CN114822342A CN 114822342 A CN114822342 A CN 114822342A CN 202110126126 A CN202110126126 A CN 202110126126A CN 114822342 A CN114822342 A CN 114822342A
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data voltage
gray scale
display
compensated
original
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张东豪
钱先锐
黄飞
李路康
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Chengdu Vistar Optoelectronics Co Ltd
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Chengdu Vistar Optoelectronics Co Ltd
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Priority to PCT/CN2021/135013 priority patent/WO2022135102A1/en
Priority to TW110145498A priority patent/TWI796865B/en
Publication of CN114822342A publication Critical patent/CN114822342A/en
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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
    • G09G3/2003—Display of colours
    • 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
    • G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
    • G09G2320/0276—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction

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Abstract

The embodiment of the invention discloses a gamma debugging method and a gamma debugging device for a display panel, which determine a display gray scale to be compensated according to a test curve and target brightness corresponding to the display gray scale; and adjusting the original data voltage grade sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value. Compared with the prior art, the method for carrying out gamma debugging by increasing the light emitting time of different sub-frames in exponential level is beneficial to reducing gray scale redundancy during gamma debugging, so that the scanning utilization rate is improved, and the problem of insufficient scanning time is solved.

Description

Gamma debugging method and device for display panel
Technical Field
The embodiment of the invention relates to the technical field of display, in particular to a gamma debugging method and device for a display panel.
Background
With the development of display technology, gamma debugging is usually required for the display panel to improve the screen quality.
In the prior art, when a display panel is driven in a digital driving mode, the problems of gray scale redundancy, low scanning utilization rate and insufficient scanning time exist during gamma debugging.
Disclosure of Invention
The invention provides a gamma debugging method and a gamma debugging device for a display panel, which aim to reduce gray scale redundancy, improve the scanning utilization rate and increase the line scanning time.
In a first aspect, an embodiment of the present invention provides a gamma debugging method for a display panel, including:
establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are all integers;
determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
and adjusting the original data voltage grade sequence to obtain a debugging data voltage grade sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value.
Optionally, the creating a lookup table of a corresponding relationship between the original gray scale and the original data voltage level sequence includes:
determining the number of data voltage levels and the number of sub-frames in the lookup table according to the maximum display gray scale; the number of the sub-frames is more than or equal to two, and the number of the data voltage grades is more than two;
determining the data voltage corresponding to each data voltage grade in the lookup table according to the required maximum display brightness and the number of the data voltage grades;
and determining an original data voltage level sequence corresponding to the original gray scale according to the size of the original gray scale.
Optionally, determining the number of data voltages and the number of subframes according to the maximum display gray scale includes:
determining the number of voltage levels and the number of sub-frames of any group of data meeting the following relationship as the number of voltage levels and the number of sub-frames of data in a lookup table:
(m-1)(h 1 +h 2 +……+h n )＞Gray max where m represents the number of data voltage levels, h i Indicating the relative light emission duration of the sub-frame with the relative shortest light emission duration of the ith sub-frame, n indicating the number of sub-frames included in one frame, Gray max Represents the maximum display gray scale, where h i Is an integer, h 1 Indicating the relative light emission duration, h, of the shortest light emission duration subframe 1 Taking the value as a unit of 1;
optionally, the number of data voltage levels in the lookup table and the number of subframes satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max ＞1.1；
optionally, the number of data voltage levels in the lookup table and the number of subframes satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max ＜1.2；
optionally, determining the data voltage corresponding to each data voltage level in the lookup table according to the required maximum display brightness and the number of the data voltage levels includes:
determining the corresponding data voltage of the display panel in a dark state as a first-level data voltage; determining a data voltage when the display panel reaches (i/(m-1)) Lmax as an (i +1) th level data voltage, wherein 1 is less than or equal to i less than or equal to (m-1), and Lmax represents the maximum display brightness;
optionally, determining an original data voltage level sequence corresponding to the original gray scale according to the size of the original gray scale includes:
determining any data voltage level sequence satisfying the following relations as an original data voltage level sequence corresponding to an original gray scale:
Figure BDA0002924059920000021
wherein k is i Representing the data voltage level of the ith sub-frame, 1 ≦ k i ≤m，Gray ini Representing the original gray level.
Optionally, before determining the display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale, the method further includes:
determining second display data according to the original gray scale corresponding to the received first display data and the lookup table; wherein, from the first bit display data to the last bit display data in the second display data, each p bit display data corresponds to a data voltage level of a sub-frame, wherein
Figure BDA0002924059920000022
Wherein x ═ np, where x denotes the number of bits of the second display data; m represents the number of data voltage levels, n represents the number of sub-frames included in one frame, n is smaller than the number of data bits included in the first display data, wherein p is more than or equal to 2;
and providing corresponding data voltage for the display panel according to the data voltage grade corresponding to each subframe in the second display data and acquiring the display brightness of the display panel to obtain a test curve.
Optionally, the adjusting the original data voltage level sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debug data voltage level sequence includes:
and adjusting the second display data according to the original gray scale adjacent to the coordinate point of the target brightness of the gray scale to be compensated and displayed on the test curve.
Optionally, determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale, including:
determining a coordinate point of the target brightness corresponding to each display gray scale on the test curve;
and determining the display gray scale of the target brightness at the coordinate point as the display gray scale to be compensated when the target original gray scale corresponding to the coordinate point is an integer and the target original gray scale corresponding to the coordinate point is a non-integer.
Optionally, determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale, including:
and judging whether a target original gray scale corresponding to a coordinate point of target brightness corresponding to each display gray scale on the test curve is larger than the maximum original gray scale or smaller than the minimum original gray scale, and if the target original gray scale corresponding to the coordinate point is larger than the maximum original gray scale or smaller than the minimum original gray scale, determining the display gray scale of the target brightness at the coordinate point as a display gray scale to be compensated.
Optionally, the adjusting the original data voltage level sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debug data voltage level sequence, and when the difference between the actual brightness corresponding to the debug data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold, determining the debug data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated, including:
adjusting the original data voltage grade sequence to obtain a debugging data voltage grade sequence under the data voltage grade in the lookup table, and adding at least one data voltage grade for debugging when the actual brightness corresponding to each debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated are both larger than or equal to a set threshold value under the data voltage grade in the lookup table so as to enable the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated to be smaller than the set threshold value;
optionally, the data voltage at the added data voltage level satisfies that, at the data voltage corresponding to the added data voltage level, the ratio of the display luminance of the display panel to the maximum luminance is less than (1/(m-1)), where m represents the number of data voltage levels.
Optionally, the adjusting, according to an original gray scale adjacent to a coordinate point of target brightness of a display gray scale to be compensated on a test curve, an original data voltage level sequence to obtain a debug data voltage level sequence, and when a difference between actual brightness corresponding to the debug data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold, determining the debug data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated, further includes:
determining sub-pixels to be compensated according to the brightness difference of the sub-pixels with the same color under the preset gray scale;
adjusting a corresponding debugging data voltage level sequence of the sub-pixel under the detection gray scale according to the brightness difference between the sub-pixel to be compensated and other sub-pixels under the same detection gray scale to obtain a secondary debugging data voltage level sequence of the sub-pixel corresponding to the detection gray scale, and determining the secondary debugging data voltage level sequence of the sub-pixel to be compensated under the detection gray scale as an updating target data voltage level sequence of the sub-pixel to be compensated under the detection gray scale when the difference value between the adjusted actual brightness of the sub-pixel to be compensated and the brightness of other sub-pixels is smaller than a set threshold value; preferably, after the sub-pixels to be compensated are determined according to the brightness difference of the sub-pixels with the same color under the preset gray scale, the method further includes:
determining compensation parameters corresponding to the sub-pixels to be compensated according to the brightness of the sub-pixels to be compensated and the brightness of other sub-pixels under different display gray scales;
after determining the sequence of the voltage levels of the updated target data of the sub-pixels to be compensated under the detection gray scale, the method further comprises the following steps:
and establishing a corresponding relation between the compensation parameters of the sub-pixels to be compensated and the updated target data voltage grade sequence.
In a second aspect, an embodiment of the present invention further provides a gamma debugging apparatus for a display panel, including:
the lookup table establishing module is used for establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are all integers;
the to-be-compensated gray scale determining module is used for determining a to-be-compensated display gray scale according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
and the target data voltage grade sequence determining module is used for adjusting the original data voltage grade sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value.
According to the gamma debugging method and device for the display panel, the display gray scale to be compensated is determined according to the test curve and the target brightness corresponding to the display gray scale; adjusting an original data voltage grade sequence according to an original gray scale adjacent to a coordinate point of target brightness of a display gray scale to be compensated on a test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when a difference value between actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value; therefore, in the embodiment, the gamma debugging is performed on the display panel in a digital-analog hybrid driving mode, and compared with the increase of the number of the digital driving data voltages, the number of the sub-frames can be relatively reduced. Compared with the prior art, the method for carrying out gamma debugging by increasing the light emitting time of different sub-frames in exponential level is beneficial to reducing gray scale redundancy during gamma debugging, thereby improving the scanning utilization rate and solving the problem of insufficient scanning time.
Drawings
FIG. 1 is a flowchart illustrating a gamma debugging method for a display panel according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a test curve provided by an embodiment of the present invention;
FIG. 3 is a schematic diagram of a gamma curve provided by an embodiment of the present invention;
FIG. 4 is a diagram illustrating sub-frame division for driving pixel circuits in a display panel within a frame according to the prior art;
FIG. 5 is a schematic diagram illustrating sub-frame division for driving pixel circuits in a display panel within a frame according to an embodiment of the present invention;
FIG. 6 is a flowchart illustrating a gamma adjustment method for a display panel according to another embodiment of the present invention;
fig. 7 is a schematic structural diagram of a display panel according to an embodiment of the present invention;
FIG. 8 is a flowchart illustrating a gamma adjustment method for a display panel according to another embodiment of the present invention;
FIG. 9 is a flowchart illustrating a gamma adjustment method for a display panel according to another embodiment of the present invention;
fig. 10 is a schematic structural diagram of a gamma debugging apparatus for a display panel according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
As described in the background art, in the prior art, when the display panel is driven in a digital driving manner, gray scale redundancy during gamma debugging, low scan utilization rate, and insufficient scan time are problems. The inventor has found that the above problems occur because there are many uncontrollable factors in the process of forming the display panel, such as the process of manufacturing the back plate and the LED chip, the process of transferring and repairing, and the existence of dust particles, and the like, which cause the gray value to jump, and the jump of the gray value needs to be solved by a scheme of increasing the bit number (data bit) of the display data when the gamma debugging is performed on the display panel driven by the digital driving method, but the method of increasing the bit number of the display data needs to increase the scanning sub-frame in one frame (one sub-frame needs to be correspondingly increased for each data bit increase), for example, when the display panel driven by the digital driving method needs to display 256 gray levels, the division of one frame into 8 sub-frames (the bit number corresponding to the display data is 8 bits) can be realized. However, if there is a transition of the gray scale value in the display panel, one frame needs to be divided into more subframes to perform gamma debugging, and the light emitting time length of different subframes increases in an exponential order, for example, into 10 subframes (the number of bits corresponding to display data is 10 bits, and the number of possible corresponding gray scales is 1024), when performing gamma debugging, 256 values are mainly selected from 1024 discrete luminance values, so that the bit number (data bit) of the display data at the utilization rate of the scanning time becomes 256/1024 ═ 1/4 when the bit number of the display data (data bit) is 8 bits, and the scanning time of each line also becomes 1/4 when the bit number of the display data is 8 bits, which causes problems of gray scale redundancy, low scanning utilization rate, and insufficient scanning time at the gamma debugging.
Based on the above reasons, the present embodiment provides a gamma debugging method for a display panel, and the gamma debugging method for a display panel of the present embodiment is suitable for the case of performing gamma debugging by using digital-analog hybrid driving. Fig. 1 is a flowchart of a gamma debugging method of a display panel according to an embodiment of the present invention, and referring to fig. 1, the gamma debugging method of the display panel includes:
step 110, establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are all integers;
specifically, in the prior art, a digital driving method generally divides a frame into a plurality of subframes, and provides a dark-state data voltage corresponding to a dark state or a bright-state data voltage corresponding to a bright state to a sub-pixel in each subframe to control the lighting time of the sub-pixel in the frame, thereby controlling the display gray scale. That is, for pure digital driving, a data voltage may be supplied to a sub-pixel as one of two data voltages (i.e., a bright-state data voltage and a dark-state data voltage) within one sub-frame. In the analog driving, the driving current flowing through the sub-pixels is controlled by controlling the magnitude of the data voltage provided to the sub-pixels, so that the control of the display gray scale is realized, and therefore, the number of the data voltages required in the analog driving is equal to the total number of the gray scales which can be displayed by the display panel. In this embodiment, a digital-analog hybrid driving method is used for gamma adjustment, and in this method, a frame can still be divided into at least two subframes, where the relative light emitting durations of different subframes may be the same or different. The data voltage corresponding to a sub-frame may be one of a plurality (more than two) of data voltages, but is much less than the total number of gray scales that can be displayed by the display panel, and one of the plurality of data voltages is provided to the sub-pixel in one sub-frame according to the size of the gray scale that is displayed.
The original data voltage level sequence comprises data voltage levels corresponding to different sub-frames in one frame, wherein the data voltage corresponding to each data voltage level can be obtained in advance and stored in the driving chip. Wherein each original data voltage level sequence corresponds to an original gray level. Optionally, in each original data voltage level sequence, the total included data voltage level is m (m)>2) Respectively, a first data voltage level Vdata 0 Second data voltage class Vdata 1 A third data voltage level Vdata 2 … … mth data voltage level Vdata m-1 First data voltage level Vdata 0 Can correspond to the data voltage of the display panel in the dark state and the second data voltage level Vdata 1 A third data voltage level Vdata 2 … … mth data voltage level Vdata m-1 The ratio of the display brightness of the corresponding display panel is 1:2: … …: (m-1). Optionally, the number of subframes included in one frame is n (n is greater than or equal to 2), which are respectively the nth subframe of the first subframe … … and the second subframe, and optionally, the ratio of the relative light-emitting time lengths corresponding to the nth subframe of the first subframe … … and the second subframe is 2 0 ：2 1 ：2 2 ：……：2 n-1 . The data voltage provided to the sub-pixels in the display panel in each of the n sub-frames is a data voltage corresponding to one of the m data voltage levels. Illustratively, the number of data voltage levels is 10 (each being the first data voltage level Vdata) 0 A second data voltage level Vdata 1 Third data voltage, etcStage Vdata 2 A fourth data voltage level Vdata 3 A fifth data voltage level Vdata 4 A sixth data voltage level Vdata 5 The seventh data voltage class Vdata 6 Eighth data voltage class Vdata 7 The ninth data voltage level Vdata 8 Tenth data voltage class Vdata 9 ) The number of the sub-frames included in one frame is 5, and the ratio of the relative light-emitting time lengths corresponding to the first sub-frame, the second sub-frame, the third sub-frame, the fourth sub-frame and the fifth sub-frame is 2 0 ：2 1 ：2 2 ：2 3 ：2 4 . Table 1 shows that when the number of corresponding data voltage levels is 10, and the number of subframes included in one frame is 5, the display panel lights only a certain subframe in one frame with the data voltage corresponding to different data voltage levels, and the corresponding original gray levels are not lighted by other subframes.
TABLE 1
Figure BDA0002924059920000071
For example, the display panel is lit up by the data voltage corresponding to the 10 th voltage level Vdata9 only in the third sub-frame, and the data voltage corresponding to the 1 st voltage level is provided to the display panel in other sub-frames (i.e. the first sub-frame, the second sub-frame, the fourth sub-frame, and the fifth sub-frame), that is, the display panel is in a dark state in other sub-frames, and the corresponding original gray scale is 36 gray scales. The manner of obtaining other original gray levels in table 1 is the same as that of obtaining the 36 gray levels, and is not described herein again.
For a certain original gray scale, different data voltage level sequences may be corresponded, for example, when the original gray scale is 200 gray scales, the corresponding data voltage level sequence may be 89199, and in the data voltage level sequence, the data voltage levels corresponding to the fifth sub-frame, the fourth sub-frame, the third sub-frame, the second sub-frame and the first sub-frame are sequentially represented from the highest bit to the lowest bit, and then the data voltage levels corresponding to the fifth sub-frame, the fourth sub-frame, the third sub-frame, the second sub-frame and the first sub-frame are respectively the eighth voltage level Vdata7, the ninth voltage level Vdata8, the first voltage level Vdata0, the ninth voltage level Vdata8 and the ninth voltage level Vdata8, and the weighting of each gray scale in table 1 is 112+64+0+16+8 ═ 200. When the original gray scale is a 200 gray scale, the corresponding data voltage level sequence may be 98411, and the data voltage levels corresponding to the fifth sub-frame, the fourth sub-frame, the third sub-frame, the second sub-frame and the first sub-frame are a ninth voltage level Vdata8, an eighth voltage level Vdata7, a fifth voltage level Vdata4, a first voltage level Vdata0 and a first voltage level Vdata0, respectively, and the weighting of each gray scale according to table 1 is 128+56+16+0+ 200. Therefore, according to the digital-analog hybrid driving gamma debugging method of the embodiment, the data voltage level sequence that can obtain the same original gray scale may include a plurality of data voltage level sequences, any one of the data voltage level sequences may be determined as the original data voltage level sequence corresponding to the original gray scale, and the data voltage level sequence may also be selected according to the actual debugging situation, which is not specifically limited herein. It should be noted, however, that the look-up table has only a fixed sequence of voltage levels of the original data corresponding to an original gray level.
Step 120, determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
specifically, the test curve may be obtained by testing the display panel according to the original data voltage level sequence corresponding to each original gray scale in the lookup table, and the actual test brightness corresponding to each original gray scale is obtained by controlling the data voltage level in each subframe (since each data voltage level corresponds to a data voltage in the driving chip, the data voltage level in each subframe is also controlled, that is, the data voltage in each subframe), so as to obtain the test curve. FIG. 2 is a schematic diagram of a test curve provided by an embodiment of the present invention, wherein the abscissa Grayini represents the original gray level and the ordinate LV represents the brightness. Under ideal display effect, the test curve should be a straight line. Since the perception of brightness by the human eye is non-linear, gamma-debugging of the display panel is required for correction. When gamma debugging is carried out, firstly, the target brightness of each display gray scale is determined according to a gamma curve (a curve of the display gray scale Grayz and the brightness percentage LV percent, wherein the brightness percentage is equal to the ratio of the brightness corresponding to the display gray scale to the brightness corresponding to the maximum display gray scale), then whether the original subframe gray scale corresponding to the same brightness can be found on the test curve by the target brightness of the display gray scale is determined, and if the original subframe gray scale corresponding to the same brightness can be found, the compensation is not needed for the display gray scale; if the gray scale cannot be found, the display gray scale needs to be compensated, and the gray scale needing to be compensated is the display gray scale to be compensated.
It should be noted that the display gray scale may not be equal to the original gray scale, and the corresponding relationship between the display gray scale and the original gray scale needs to be determined according to the brightness, for example, when the display gray scale is 64, the corresponding target brightness is determined to be 30nit according to the gamma curve, and in the test curve, the original gray scale corresponding to the brightness 30nit is 30, and then the 64 display gray scale corresponds to the 30 original gray scale.
Fig. 3 is a schematic diagram of a gamma curve provided by an embodiment of the present invention, which may be a gamma2.2 curve. For example, when the display gray level is 125 gray levels (point M in fig. 3), the corresponding target brightness is determined to be 60nit according to the gamma curve, a coordinate point can be found on the test curve according to the target brightness 60nit, the original gray level corresponding to the coordinate point (point N in fig. 2) is between 62 gray levels and 63 subframe gray levels, and the original gray levels are integers, so that the original gray level corresponding to the brightness of 60nit cannot be found on the test curve, that is, the brightness display of 60nit cannot be realized according to the original data voltage level sequence of the lookup table. Therefore, the 125 display gray level can be determined as the display gray level to be compensated. On the contrary, if the corresponding target brightness of a certain display gray scale can find the corresponding original gray scale on the test curve, the display gray scale is not determined as the display gray scale to be compensated. For example, for the 230 display gray scale, if the target brightness is determined to be 250nit according to the gamma curve, and the original gray scale (235 original gray scale) with the brightness of 250nit can be found on the test curve, then the 230 gray scale is not determined as the display gray scale to be compensated.
With continued reference to fig. 2, the slope of the test curve between the first line P1 and the second line P2 has a sudden change, and the slope of the test curve between the third line P3 and the fourth line P4 also has a sudden change, so that when the target brightness falls on the test curve between the first line P1 and the second line P2 and the test curve between the third line P3 and the fourth line P4, the probability that the display gray scale corresponding to the target brightness is the gray scale to be compensated is higher. Therefore, the brightness range corresponding to the slope abrupt change position on the test curve can be preferably found, and whether the brightness range is between the brightness corresponding to the two adjacent original subframes or not is determined; if so, determining whether the target brightness corresponding to the display gray scale is in the brightness range; if so, determining the display gray scale as the display gray scale to be compensated, and further quickly finding the display gray scale to be compensated.
Step 130, adjusting the original data voltage grade sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value.
In this embodiment, when the display panel is lit up according to the original data voltage level sequence corresponding to each original gray scale in the lookup table, and the original data voltage level sequence corresponding to each original gray scale in the lookup table cannot make the display panel reach the target brightness corresponding to the display gray scale to be compensated, the target brightness corresponding to the display gray scale to be compensated may be displayed on the display panel by adjusting the original data voltage level sequence, and the adjusted data voltage level sequence is recorded as the adjusted data voltage level sequence. Specifically, a target original gray scale (which cannot be realized by a data voltage level sequence in a lookup table) actually corresponding to the target brightness can be determined according to a coordinate point of the target brightness of the display gray scale to be compensated on the test curve, then an original gray scale adjacent to the target original gray scale and capable of being realized by the data voltage level sequence in the lookup table is determined, and the original data voltage level sequence is adjusted according to the original gray scale capable of being realized by the data voltage level sequence in the lookup table. Specifically, since the brightness of the display panel corresponding to different data voltage level sequences corresponding to the same original gray scale may have slight difference, the adjusted data voltage level sequence may be determined as a different data voltage level sequence corresponding to the same original gray scale as the original data voltage level sequence (for example, when the coordinate point of the display gray scale to be compensated on the test curve is between the original gray scale 200 and the original gray scale 201, if the difference between the original data voltage sequence corresponding to the original gray scale 200 (for example, 89199) in the lookup table and the target brightness is not less than the set threshold, the adjusted data voltage sequence may be determined as 98411 for debugging again, and similarly, the original data voltage sequence corresponding to the original gray scale 201 may also be adjusted in the above manner), and if the brightness of the display panel still cannot meet the requirement, the adjusted data voltage level sequence may be obtained by increasing the data voltage level, and enabling the finally determined adjusting data voltage level sequence to meet the condition that the difference between the brightness of the display panel and the target brightness is smaller than a set threshold value.
FIG. 4 is a diagram illustrating sub-frame division for driving pixel circuits in a display panel within a frame according to the prior art; fig. 5 is a schematic diagram of sub-frame division for driving pixel circuits in a display panel in one frame according to an embodiment of the present invention. In fig. 4 and 5, the abscissa time represents the relative light-emitting time period, and the ordinate ROW represents the pixel ROW in the display panel. With reference to fig. 4 and fig. 5, where the Frame represents a Frame, F1, F2, F3, F4, F5, F6, F7, and F8 may correspond to 8 subframes required to achieve the maximum gray scale 255 in the prior art, and the relative light-emitting duration ratio of the eight original subframes F1, F2, F3, F4, F5, F6, F7, and F8 is 1:2:4:8:16:32:64:128, and to perform gamma debugging under pure digital driving, at least one subframe, for example, subframe F9, needs to be additionally added, and the relative light-emitting duration is 2 times of the relative light-emitting duration of the eighth subframe F8. In this embodiment, when the data voltage level is 10, 255 grays of gray can be displayed and gamma-adjusted only by 5 subframes (when the data voltage level is 10 and the number of subframes included in one frame is 5, the maximum display grayscale that can be realized according to table 1 is 9+18+36+72+144 ═ 279, and therefore includes 24 grays higher than the 255 grays, that is, includes redundant grays), that is, F1, F2, F3, F4, and F5 in fig. 5, and the relative light-emitting time length ratio of the 5 subframes is 1:2:4:8:16: 32.
According to the gamma debugging method of the display panel, the display gray scale to be compensated is determined according to the test curve and the target brightness corresponding to the display gray scale; adjusting an original data voltage grade sequence according to an original gray scale adjacent to a coordinate point of target brightness of a display gray scale to be compensated on a test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence under the display gray scale to be compensated as the target data voltage grade sequence of the display gray scale to be compensated when a difference value between actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value; therefore, in the embodiment, the gamma debugging is performed on the display panel in a digital-analog hybrid driving mode, and compared with the increase of the number of the digital driving data voltages, the number of the sub-frames can be relatively reduced. Compared with the prior art, the method for carrying out gamma debugging by increasing the light emitting time of different sub-frames in exponential level is beneficial to reducing gray scale redundancy during gamma debugging, thereby improving the scanning utilization rate and solving the problem of insufficient scanning time.
Fig. 6 is a flowchart of another gamma adjustment method for a display panel according to an embodiment of the present invention, and referring to fig. 6, the gamma adjustment method for a display panel includes:
step 211, determining the number of data voltage levels and the number of sub-frames in the lookup table according to the maximum display gray scale; the number of the sub-frames is more than or equal to two, and the number of the data voltage grades is more than two;
the number of the sub-frames is equal to 1, namely the analog driving mode, which does not belong to the condition of digital-analog hybrid driving gamma debugging. In this embodiment, the number of the sub-frames is greater than or equal to two, the number of the data voltage levels is greater than two, and the analog data voltages corresponding to different data voltage levels are different, so that the number of the sub-frames and the number of the data voltage levels in this embodiment ensure that the driving mode for the display panel is a digital-analog hybrid driving mode.
In this embodiment, the number of the sub-frames and the number of the data voltage levels need to be set to ensure that when each sub-frame lights up the display panel with the data voltage corresponding to the maximum data voltage level, the display panel can reach or exceed the brightness corresponding to the maximum display gray scale, where the maximum display gray scale corresponds to the maximum display brightness, and the maximum display brightness may be predetermined according to the requirement.
Optionally, this step 211 may include:
and determining the voltage level number and the sub-frame number of any group of data meeting the following relation as the data voltage level number and the sub-frame number in the lookup table:
(m-1)(h 1 +h 2 +……+h n )＞Gray max where m represents the number of data voltage levels, h i Indicating the relative light emission duration of the sub-frame with the relative shortest light emission duration of the ith sub-frame, n indicating the number of sub-frames included in one frame, Gray max Represents the maximum display gray scale, where h i Is an integer, h 1 Indicating the relative light emission duration, h, of the shortest light emission duration subframe 1 The value is in units of 1.
Alternatively, h1: h2: … …: hn ═ 2 0 ：2 1 ：2 2 ：……：2 n-1 . Taking the maximum display gray scale of 255 as an example, m is 10, and n is 5 in table 1, which is the number of data voltage levels and the number of sub-frames that satisfy the above relationship; however, there may be a plurality of sets of the number of data voltage levels and the number of subframes satisfying the above relationship, and for example, m-18 and n-4 are also a set of the number of data voltage levels and the number of subframes satisfying the above relationship.
When gamma debugging is performed, redundant gray scales need to be set, so in an optional embodiment of the present invention, the number of data voltage levels and the number of sub-frames in the lookup table satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max when each sub-frame in a frame provides data voltage corresponding to the maximum data voltage level to the display panel, the ratio of the obtained original gray scale to the maximum display gray scale is larger than 1.1, so that the redundancy of the gray scales is ensured, and the display gray scales can reach the target brightness after gamma debugging.
As described above, when performing gamma debugging, it is necessary to ensure that the number of data voltage levels and the number of subframes are set to ensure that the number of redundant gray scales is a certain number, but the number of redundant gray scales does not need to be set to a large number, so as to reduce the difficulty in implementing a power supply for supplying data voltages and the scanning frequency.
Optionally, the number of data voltage levels in the lookup table and the number of subframes satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max less than 1.2; on the basis of ensuring gray scale redundancy, the number of data voltage grades and the number of subframes are not required to be set too much, so that the requirement on a power supply for providing data voltage is reduced, and the scanning frequency is reduced.
In the prior art, when 255-level gray scale display is realized by pure digital driving, the number of sub-frames divided into one frame needs to be 8. Therefore, optionally, when the maximum display gray scale is 255 gray scales in the embodiment, h1: h2: … …: hn ═ 2 0 ：2 1 ：2 2 ：……：2 n-1 When n can be set<8, further achieving the reduction of the scanning frequency; in order to reduce the difficulty in implementing the power supply for supplying the data voltage, in this embodiment, when the maximum display gray scale is 255 gray scales, the number of data voltage levels may be set to be less than 20.
Step 212, determining the data voltage corresponding to each data voltage grade in the lookup table according to the required maximum display brightness and the number of the data voltage grades;
optionally, the step 212 includes: determining the corresponding data voltage of the display panel in a dark state as a first-level data voltage; the data voltage at which the display panel reaches (i/(m-1)) Lmax, where 1 ≦ i ≦ m-1, and Lmax represents the maximum display luminance, is determined as the (i +1) th level data voltage.
The corresponding data voltage when the display panel is in the dark state can enable the display panel to be any data voltage in the dark state; in an optional embodiment of the present invention, the first level data voltage may be a minimum voltage when the display panel is in a dark state, so as to save power consumption of the display panel in the dark state.
In this embodiment, the display brightness of the display panel can be divided into equal (m-1) segments from the dark state (the display brightness is 0) to the maximum display brightness according to the required maximum display brightness, and the gamma curve corresponds to m coordinate points (the points where the triangles are located in fig. 3). Through adjustment of the data voltage grade sequence, the display brightness of the display panel sequentially reaches the brightness corresponding to the m coordinate points, and then the data voltage corresponding to each data voltage grade is obtained.
And step 213, determining an original data voltage level sequence corresponding to the original gray scale according to the size of the original gray scale.
Determining any data voltage level sequence satisfying the following relations as a data voltage level sequence corresponding to the original gray scale:
Figure BDA0002924059920000121
wherein k is i Representing the data voltage level of the ith sub-frame, 1 ≦ k i ≤m，Gray ini Representing the original gray level.
Still taking the case shown in table 1 as an example, when the original grayscale is 200, the corresponding data voltage level sequence may be 89199, and in the data voltage level sequence, the data voltage levels corresponding to the fifth sub-frame, the fourth sub-frame, the third sub-frame, the second sub-frame and the first sub-frame are sequentially represented from the highest bit to the lowest bit, that is, k5 is 9, k4 is 8, k3 is 1, k2 is 9, k1 is 9, that is, the data voltage levels corresponding to the fifth sub-frame, the fourth sub-frame, the third sub-frame, the second sub-frame and the first sub-frame are respectively the eighth voltage level Vdata7, the ninth voltage level Vdata8, the first voltage level vd 0, the ninth voltage level Vdata8 and the ninth voltage level Vdata8, and the weighting of the grays in table 1 is 112+64+0+16+8, 200.
Specifically, before the gray scale to be compensated is determined according to the test curve, the test curve needs to be acquired. Wherein the obtaining of the test curve may comprise the following steps 220 and 230.
Step 220, determining second display data according to the original gray scale corresponding to the received first display data and the lookup table;
wherein, from the first bit display data to the last bit display data in the second display data, each p bit display data corresponds to a data voltage level of a sub-frame, wherein
Figure BDA0002924059920000122
Wherein x ═ np, where x denotes the number of bits of the second display data; wherein m represents the number of data voltage levels, n represents the number of sub-frames included in one frame, and n is less than the number of data bits included in the first display data, wherein p is more than or equal to 2.
Specifically, after receiving an original gray scale corresponding to first display data in the motherboard, the driver chip may determine an original data voltage level sequence corresponding to the original gray scale in the lookup table according to the original gray scale, where the original data voltage level sequence includes data voltage levels corresponding to different subframes in one frame, and when the number of the data voltage levels is greater than 2, the data voltage level sequence cannot be represented by one-bit binary data, and thus a plurality of data bits need to be set to correspond to one data voltage level.
The second display data may be used to represent the original data voltage level sequence, where each p bits of the second display data corresponds to a data voltage level of a subframe, and where the display data of each data bit in the second display data is 0 or 1 (i.e., the data of the display panel is binary data).
Figure BDA0002924059920000131
I.e. to ensure that p bits of display data can represent each data voltage level. Illustratively, when the data voltage levels are 10, and the data of the display panel is binary data, the minimum value of p is 4. Optionally, the value of p is chosen to satisfy
Figure BDA0002924059920000132
The minimum value of (3) is sufficient. Illustratively, one frame includes 5 subframes, the data voltage level is 10, p is 4, and the data bit 4 × 5 of the second display data is 20. That is, every 4 bits of the 20-bit display data of the second display data represents a data voltage level.
Step 230, providing corresponding data voltages to the display panel according to the data voltage levels corresponding to the sub-frames in the second display data and obtaining the display brightness of the display panel to obtain a test curve.
Fig. 7 is a schematic structural diagram of a display panel according to an embodiment of the present invention, and referring to fig. 7, the display panel may include a pixel array 310, a data processor 320, a row scanning circuit 330, and a column scanning circuit 340, where after the data processor 310 receives first display data corresponding to an original gray scale from a motherboard, the data processor determines an original data voltage level sequence according to a pre-stored lookup table, and generates second display data representing the original data voltage level sequence according to the original data voltage level sequence. Since each p bit in the second display data corresponds to a data voltage level, and each data voltage level corresponds to a data voltage in the data processor 310, that is, each p bit in the second display data corresponds to a data voltage, the data processor 310 controls the column scanning circuit 320 (which may correspond to the driving chip in the above-described embodiment) according to the second display data to apply the corresponding data voltage to the pixel circuit array 310 in each sub-frame, and the display brightness of the display panel may be obtained by a brightness obtaining device (e.g., a CCD camera), and a test curve may be obtained according to the brightness corresponding to each data voltage level sequence.
Step 240, determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness; this step is the same as step 120 in the above embodiments, and is not described herein again.
Step 250, adjusting an original data voltage grade sequence according to an original gray scale adjacent to a coordinate point of target brightness of a display gray scale to be compensated on a test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when a difference value between actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value;
the second display data represents the original data voltage grade sequence, and the purpose of adjusting the original data voltage grade sequence can be achieved by adjusting the second display data. When the second display data is adjusted, the display data of any bit in the second display data can be adjusted to adjust the second display data.
Fig. 8 is a flowchart of another gamma adjustment method for a display panel according to an embodiment of the present invention, and referring to fig. 8, the gamma adjustment method for a display panel includes:
step 410, establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; step 410 is the same as step 110 in the above embodiment, and is not described again.
Step 421, determining a coordinate point of the target brightness corresponding to each display gray scale on the test curve;
specifically, when a coordinate point of the target brightness corresponding to a certain display gray scale on the test curve is determined, a point with the brightness equal to the target brightness can be found on the test curve as the coordinate point of the target brightness corresponding to the display gray scale on the test curve. For example, if the target brightness corresponding to a certain display gray scale is 60nit, finding a coordinate point with the brightness of 60nit on the test curve is the coordinate point of the target brightness corresponding to the display gray scale on the test curve.
And 422, judging whether the target original gray scale corresponding to the coordinate point is an integer or not, and determining the display gray scale of the target brightness at the coordinate point as the display gray scale to be compensated when the target original gray scale corresponding to the coordinate point is a non-integer.
After the coordinate point is determined, a target original gray scale corresponding to the coordinate point can be determined, when the original gray scale corresponding to the coordinate point is not an integer, the original gray scale corresponding to the coordinate point does not exist in an original data voltage level sequence in a lookup table, namely, the target brightness cannot be realized through the original data voltage level sequence, therefore, when the original subframe gray scale corresponding to the coordinate point is not an integer, a display gray scale corresponding to the coordinate point is determined as a display gray scale to be compensated, wherein the display gray scale corresponding to the coordinate point is the display gray scale with the brightness value of the coordinate point as the target brightness.
And 423, judging whether a target original gray scale corresponding to the target brightness corresponding to each display gray scale on the coordinate point of the test curve is larger than the maximum original gray scale or smaller than the minimum original gray scale, and if the target original gray scale corresponding to the coordinate point is larger than the maximum original gray scale or smaller than the minimum original gray scale, determining the display gray scale of the target brightness at the coordinate point as the display gray scale to be compensated.
Specifically, when the original gray scale corresponding to the coordinate point is greater than the maximum original gray scale or less than the minimum original gray scale, the data voltage level sequence in the lookup table cannot reach the target original gray scale of the coordinate point, and therefore, the target brightness corresponding to the display gray scale cannot be realized through the data voltage level sequence in the lookup table, and therefore, when the original gray scale corresponding to the coordinate point is greater than the maximum original gray scale or less than the minimum original gray scale, the display gray scale corresponding to the coordinate point is determined as the display gray scale to be compensated, where the display gray scale corresponding to the coordinate point is the display gray scale with the brightness value of the coordinate point as the target brightness.
And 430, adjusting the original data voltage grade sequence to obtain a debugging data voltage grade sequence under the data voltage grade in the lookup table, and adding at least one data voltage grade for debugging when the difference between the actual brightness corresponding to each debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated under the data voltage grade in the lookup table is larger than or equal to a set threshold value so that the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated are smaller than the set threshold value.
Specifically, when the original data voltage level sequence is adjusted, the data voltage level corresponding to at least one subframe in one frame can be adjusted to perform debugging by adjusting the data voltage level corresponding to at least one subframe in one frame under the data voltage level included in the lookup table, when the actual brightness corresponding to each debugging data voltage level sequence under the data voltage level in the lookup table cannot meet the debugging requirement, the data voltage level can be added in a manner of adding the data voltage level so that at least one subframe in one frame corresponds to the added data voltage level, and when the actual brightness corresponding to the debugging data voltage level sequence and the target brightness of the display gray scale to be compensated are smaller than a set threshold value, the debugging data voltage level sequence is determined as the target data voltage level sequence corresponding to the display gray scale to be compensated.
It should be noted that, in this embodiment, step 422 and step 423 are two parallel steps, and in other alternative embodiments of the present invention, after step 410 is executed, only step 422 may be executed, and then step 430 is executed; step 423 may be performed after step 410 is performed, and then step 430 is performed; when step 422 and step 423 are executed after step 410 is executed, the present embodiment does not specifically limit the execution sequence of step 422 and step 423, for example, step 422 may be executed first and then step 423, step 422 may be executed after step 423 is executed, step 422 and step 423 may be executed simultaneously, and step 430 is executed after both step 422 and step 423 are executed.
Optionally, the data voltage at the added data voltage level satisfies that, at the data voltage corresponding to the added data voltage level, the ratio of the display luminance of the display panel to the maximum luminance is less than (1/(m-1)), where m represents the number of data voltage levels.
The inventor researches and finds that the gamma debugging difficulty is larger under low gray scale (which can correspond to the display gray scale of 0-128). The display brightness corresponding to the data voltage level in the lookup table increases by an integral multiple, so that the target brightness corresponding to the low gray scale may not be realized through the data voltage level in the lookup table. In this embodiment, the ratio of the display luminance of the display panel to the maximum luminance is less than (1/(m-1)) at the data voltage corresponding to the added data voltage level, that is, the display luminance of the display panel is less than the display luminance corresponding to the second data voltage level at the data voltage corresponding to the added data voltage level. Moreover, in the embodiment, when the data voltage corresponding to the added data voltage level is set to be lower than the ratio of the display brightness of the display panel to the maximum brightness, which is less than (1/(m-1)), the non-integer target original gray scale is ensured to be realized.
Still taking the example that the number of data voltage levels in the lookup table is 10 and the number of subframes included in one frame is 5, two data voltage levels, i.e., an eleventh data voltage level Vdata10 and a twelfth data voltage level Vdata11, are added on the basis of table 1, as shown in table 2. For example, in one frame, the display panel is only lit up by the data voltage corresponding to the 11 th voltage level Vdata10 in the sub-frame 4, and the data voltages corresponding to the other sub-frames provide the data voltage corresponding to the 1 st voltage level to the display panel, that is, the display panel is in a dark state in the other sub-frames, and the corresponding original gray scale is 0.0102 gray scale.
TABLE 2
Figure BDA0002924059920000161
Because the original gray scales in the lookup table are integers, the original gray scales corresponding to the debugging data voltage level sequence can not be integers after the addition meets the condition that the ratio of the display brightness of the display panel to the maximum brightness is smaller than the data voltage level (1/(m-1)) under the data voltage corresponding to the added data voltage level, and when the target brightness corresponding to the display gray scale to be compensated cannot pass through the data voltage level sequence in the lookup table (the corresponding original gray scales are all integers), the original gray scale corresponding to the target brightness of the display gray scale to be compensated can be realized through the added data voltage level and the data voltage level in the lookup table, so that the difference between the display brightness corresponding to the debugging data voltage level sequence and the target brightness of the gray scale to be compensated can be smaller than the set threshold value.
The above embodiments are all applicable to gamma debugging of the display panel as a whole. Due to uncontrollable factors in the process, defects may exist in the individual sub-pixels, resulting in differences in display brightness between the individual sub-pixels and most of other sub-pixels, and mura phenomenon. After the gamma adjustment is performed on the whole, the demora is performed on the defective individual sub-pixels, so that the display panel achieves a better display effect. Fig. 9 is a flowchart of another gamma adjustment method for a display panel according to an embodiment of the present invention, and referring to fig. 9, the gamma adjustment method for a display panel includes:
step 510, establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different sub-frames in one frame; the original gray scales in the lookup table are all integers; step 510 is the same as step 110 in the above embodiment, and is not described again.
Step 520, determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness; the step 520 is the same as the step 120 in the above embodiment, and will not be described herein again.
Step 530, adjusting an original data voltage level sequence according to an original gray scale adjacent to a coordinate point of target brightness of a display gray scale to be compensated on a test curve to obtain a debugging data voltage level sequence, and determining the debugging data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated when a difference value between actual brightness corresponding to the debugging data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value; this step 530 is the same as step 130 in the above embodiment, and is not described herein again;
step 540, determining sub-pixels to be compensated according to the brightness difference of the sub-pixels with the same color under the preset gray scale;
specifically, the luminance of the color sub-pixels of each pixel in the display panel can be obtained by a luminance obtaining instrument, such as a CCD camera, so that the luminance difference between different sub-pixels can be determined. When the sub-pixels to be compensated are determined, the sub-pixels with the brightness obviously lower than that of most of the sub-pixels in the display panel under the preset gray scale can be determined as the sub-pixels to be compensated, or the sub-pixels with the brightness obviously higher than that of most of the sub-pixels in the display panel can be determined as the sub-pixels to be compensated.
And 550, adjusting the corresponding debugging data voltage level sequence of the sub-pixel under the detection gray scale according to the brightness difference between the sub-pixel to be compensated and other sub-pixels under the same detection gray scale to obtain a secondary debugging data voltage level sequence of the sub-pixel corresponding to the detection gray scale, and determining the secondary debugging data voltage level sequence of the sub-pixel to be compensated under the detection gray scale as an updating target data voltage level sequence of the sub-pixel to be compensated under the detection gray scale when the difference value between the adjusted actual brightness of the sub-pixel to be compensated and the brightness of other sub-pixels is smaller than a set threshold value.
Specifically, after the step 530 is completed, the voltage level sequences of the target data corresponding to the same color sub-pixels in the display panel under a gray scale to be compensated are all the same. In this step, the corresponding debugging data voltage level sequence of the sub-pixel (i.e. the target data voltage level sequence obtained in step 530) is adjusted according to the brightness difference between the sub-pixel to be compensated and other sub-pixels under the same detection gray scale to obtain a secondary debugging data voltage level sequence, so that the difference value between the adjusted actual debugging brightness of the sub-pixel to be compensated and the brightness of other sub-pixels is smaller than the set threshold, and when the difference value between the adjusted actual debugging brightness of the sub-pixel to be compensated and the brightness of other sub-pixels is smaller than the set threshold, the corresponding secondary debugging data voltage level sequence determines the updated target data voltage level sequence of the sub-pixel to be compensated under the detection gray scale. When the detected gray scale is equal to the display gray scale to be compensated, the target data voltage level sequence of the sub-pixel to be compensated (the gamma data of the same color obtained in step 530 and the same sub-pixel) can be updated by the updated target data voltage level sequence, thereby improving the mura phenomenon of the display panel.
The preset gray scale in step 540 and the detected gray scale in step 550 are both display gray scales.
On the basis of the above technical solution, optionally, after step 540, the method further includes:
determining compensation parameters corresponding to the sub-pixels to be compensated according to the brightness of the sub-pixels to be compensated and other sub-pixels under different display gray scales; after the step 550, the method further includes: and establishing a corresponding relation between the compensation parameters of the sub-pixels to be compensated and the updated target data voltage grade sequence.
In this step, the brightness of the sub-pixel to be compensated and the brightness of the other sub-pixels under three different display gray scales are optionally obtained according to the brightness of the sub-pixel to be compensated and the brightness of the other sub-pixels under at least two different display gray scales. For example, a compensation function of an actual display gray scale corresponding to the target gray scale and the luminance of the sub-pixel to be compensated may be determined according to the luminance of the sub-pixel to be compensated and the luminance of the other sub-pixels under different display gray scales, and for example, when the compensation function is Y ═ AX + B, A, B is a compensation parameter; when the compensation function is Y ═ AX 2 A, B, C is the compensation parameter when + BX + C; wherein Y in the compensation function represents the target gray scale of the sub-pixel to be compensated, and X represents the actual display gray scale of the sub-pixel to be compensated. After the compensation parameters are determined, the mapping corresponding relation between the compensation parameters of the sub-pixels to be compensated and the updated target data voltage level sequence can be established, and then the display panel is driven to display according to the mapping corresponding relation in the subsequent normal display process after gamma debugging.
Fig. 10 is a schematic structural diagram of a gamma debugging apparatus for a display panel according to an embodiment of the present invention, and referring to fig. 10, the gamma debugging apparatus for a display panel includes:
a lookup table establishing module 610, configured to establish a lookup table of a corresponding relationship between an original gray scale and an original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are all integers;
a to-be-compensated gray scale determining module 620, configured to determine a to-be-compensated display gray scale according to the test curve and target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
and the target data voltage level sequence determining module 630 is configured to adjust the original data voltage level sequence according to an original gray scale adjacent to a coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debug data voltage level sequence, and determine the debug data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated when a difference between actual brightness corresponding to the debug data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (10)

1. A gamma debugging method of a display panel is characterized by comprising the following steps:
establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are integers;
determining a display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
and adjusting the original data voltage grade sequence to obtain a debugging data voltage grade sequence according to the original gray scale of the target brightness of the display gray scale to be compensated, which is adjacent to the coordinate point on the test curve, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value.
2. The gamma debugging method of claim 1, wherein the establishing the lookup table of the corresponding relationship between the original gray levels and the original data voltage level sequences comprises:
determining the number of data voltage levels and the number of sub-frames in the lookup table according to the maximum display gray scale; the number of the sub-frames is more than or equal to two, and the number of the data voltage grades is more than two;
determining the data voltage corresponding to each data voltage grade in the lookup table according to the required maximum display brightness and the number of the data voltage grades;
and determining the original data voltage level sequence corresponding to the original gray scale according to the size of the original gray scale.
3. The gamma debugging method of claim 2, wherein the determining the number of data voltages and the number of sub-frames according to the maximum display gray scale comprises:
determining the number of the data voltage levels and the number of the sub-frames of any group meeting the following relations as the number of the data voltage levels and the number of the sub-frames in the lookup table:
(m-1)(h 1 +h 2 +……+h n )＞Gray max where m represents the number of data voltage levels, h i Indicating the relative light emission duration of the sub-frame with the relative shortest light emission duration of the ith sub-frame, n indicating the number of sub-frames included in one frame, Gray max Represents the maximum display gray scale, wherein h i Is an integer of h 1 Indicating the relative light emission duration, h, of the shortest light emission duration subframe 1 Taking the value as a unit of 1;
preferably, the number of data voltage levels and the number of subframes in the lookup table satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max ＞1.1；
preferably, the number of data voltage levels and the number of subframes in the lookup table satisfy the following relationship:
(m-1)(h 1 +h 2 +……+h n )/Gray max ＜1.2；
preferably, the determining the data voltage corresponding to each data voltage level in the lookup table according to the required maximum display brightness and the number of the data voltage levels includes:
determining the corresponding data voltage of the display panel in a dark state as a first-level data voltage; determining a data voltage of the display panel reaching (i/(m-1)) Lmax as an (i +1) th level data voltage, wherein 1 is less than or equal to i less than or equal to (m-1), and Lmax represents maximum display brightness;
preferably, the determining the original data voltage level sequence corresponding to the original gray scale according to the size of the original gray scale includes:
determining any data voltage level sequence satisfying the following relations as an original data voltage level sequence corresponding to the original gray scale:
Figure FDA0002924059910000021
wherein k is i Representing the data voltage level of the ith sub-frame, 1 ≦ k i ≤m，Gray ini Representing the original gray level.
4. The gamma debugging method of claim 2, wherein before determining the display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale, the method further comprises:
determining second display data according to the original gray scale corresponding to the received first display data and the lookup table; wherein, from the first bit display data to the last bit display data in the second display data, each p bit display data corresponds to the data voltage level of a subframe, wherein
Figure FDA0002924059910000031
Wherein x ═ np where x denotes the number of bits of the second display data; m represents the number of data voltage levels, n represents the number of sub-frames included in one frame, n is smaller than the number of data bits included in the first display data, wherein p is larger than or equal to 2;
and providing corresponding data voltage for the display panel according to the data voltage grade corresponding to each subframe in the second display data and acquiring the display brightness of the display panel to obtain the test curve.
5. The gamma debugging method of claim 4, wherein the adjusting the original data voltage level sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain the debugging data voltage level sequence comprises:
and adjusting the second display data according to the original gray scale of the target brightness of the display gray scale to be compensated, which is adjacent to the coordinate point on the test curve.
6. The gamma debugging method of the display panel of any one of claims 1-5, wherein the determining the display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale comprises:
determining a coordinate point of the target brightness corresponding to each display gray scale on the test curve;
and judging whether the target original gray scale corresponding to the coordinate point is an integer or not, and determining the display gray scale of the target brightness at the coordinate point as the display gray scale to be compensated when the target original gray scale corresponding to the coordinate point is a non-integer.
7. The gamma debugging method of the display panel of any one of claims 1-5, wherein the determining the display gray scale to be compensated according to the test curve and the target brightness corresponding to the display gray scale comprises:
and judging whether a target original gray scale corresponding to the target brightness corresponding to each display gray scale on the coordinate point on the test curve is larger than a maximum original gray scale or smaller than a minimum original gray scale, and if the target original gray scale corresponding to the coordinate point is larger than the maximum original gray scale or smaller than the minimum original gray scale, determining the display gray scale of the target brightness at the coordinate point as a display gray scale to be compensated.
8. The gamma debugging method of the display panel according to any one of claims 1 to 7, wherein the adjusting the original data voltage level sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage level sequence, and when the difference between the actual brightness corresponding to the debugging data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold, determining the debugging data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated, comprises:
adjusting the original data voltage grade sequence to obtain a debugging data voltage grade sequence under the data voltage grade in the lookup table, and adding at least one data voltage grade for debugging when the actual brightness corresponding to each debugging data voltage grade sequence under the data voltage grade in the lookup table and the target brightness of the display gray scale to be compensated are both larger than or equal to the set threshold value so that the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated are smaller than the set threshold value;
preferably, the data voltage at the added data voltage level satisfies that, at the data voltage corresponding to the added data voltage level, a ratio of the display luminance of the display panel to the maximum luminance is less than (1/(m-1)), where m represents the number of data voltage levels.
9. The gamma debugging method of the display panel according to any one of claims 1 to 8, wherein after adjusting the original data voltage level sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage level sequence, and when the difference between the actual brightness corresponding to the debugging data voltage level sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold, determining the debugging data voltage level sequence as the target data voltage level sequence of the display gray scale to be compensated, the method further comprises:
determining sub-pixels to be compensated according to the brightness difference of the sub-pixels with the same color under the preset gray scale;
adjusting a debugging data voltage level sequence corresponding to the sub-pixel under the detection gray scale according to the brightness difference between the sub-pixel to be compensated and other sub-pixels under the same detection gray scale to obtain a secondary debugging data voltage level sequence corresponding to the detection gray scale, and when the difference value between the adjusted actual brightness of the sub-pixel to be compensated and the brightness of other sub-pixels is smaller than a set threshold value, determining the secondary debugging data voltage level sequence corresponding to the sub-pixel to be compensated under the detection gray scale as an updating target data voltage level sequence of the sub-pixel to be compensated under the detection gray scale; preferably, after the sub-pixels to be compensated are determined according to the brightness difference of the sub-pixels with the same color under the preset gray scale, the method further includes:
determining compensation parameters corresponding to the sub-pixels to be compensated according to the brightness of the sub-pixels to be compensated and the brightness of other sub-pixels under different display gray scales;
after determining the update target data voltage level sequence of the sub-pixel to be compensated under the detection gray scale, the method further comprises the following steps:
and establishing a corresponding relation between the compensation parameters of the sub-pixels to be compensated and the updated target data voltage level sequence.
10. A gamma debugging device of a display panel is characterized by comprising:
the lookup table establishing module is used for establishing a lookup table of the corresponding relation between the original gray scale and the original data voltage level sequence; the original data voltage level sequence comprises data voltage levels corresponding to different subframes in one frame; the original gray scales in the lookup table are integers;
the to-be-compensated gray scale determining module is used for determining a to-be-compensated display gray scale according to the test curve and the target brightness corresponding to the display gray scale; the test curve is a relation curve between each original data voltage level sequence in the lookup table and corresponding actual test brightness;
and the target data voltage grade sequence determining module is used for adjusting the original data voltage grade sequence according to the original gray scale adjacent to the coordinate point of the target brightness of the display gray scale to be compensated on the test curve to obtain a debugging data voltage grade sequence, and determining the debugging data voltage grade sequence as the target data voltage grade sequence of the display gray scale to be compensated when the difference value between the actual brightness corresponding to the debugging data voltage grade sequence and the target brightness of the display gray scale to be compensated is smaller than a set threshold value.
CN202110126126.3A 2020-12-23 2021-01-29 Gamma debugging method and device for display panel Pending CN114822342A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116072058A (en) * 2023-01-31 2023-05-05 武汉天马微电子有限公司 Driving method and driving device of display panel and display device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116072058A (en) * 2023-01-31 2023-05-05 武汉天马微电子有限公司 Driving method and driving device of display panel and display device
CN116072058B (en) * 2023-01-31 2024-06-11 武汉天马微电子有限公司 Driving method and driving device of display panel and display device

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