Method for generating Demura compensation data of AMOLED (Active Matrix / Organic Light Emitting Diode) panel and related equipment

Abstract

The invention provides a Demura compensation data generation method of an AMOLED (Active Matrix / Organic Light Emitting Diode) panel and related equipment. The method comprises the following steps: respectively acquiring corresponding brightness data of each pixel position on a target AMOLED display panel when a multi-stage typical gray scale is input under a multi-stage typical display brightness value and a multi-stage typical refresh rate; constructing a brightness-gray scale mapping model according to a mapping relation between the brightness data and each stage of typical gray scale; counting the brightness data to obtain a brightness mean value as standard brightness, and importing each brightness-gray scale mapping model to obtain an actual expected gray scale of each pixel position; the difference value between the actual expected gray scale and the input typical gray scale is solved, the gray scale compensation value of each pixel position is obtained and used for constructing a compensation lookup table, interpolation fitting is carried out on the compensation lookup table, the compensation lookup table of the target AMOLED display panel under the full display brightness value, the full refresh rate and the full gray scale is obtained, the brightness uniformity of the panel is improved, and the display quality of the AMOLED display panel is improved. And the production yield is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a method for generating Demura compensation data of an AMOLED panel and related equipment. Background Art

[0002] Active-matrix organic light emitting diode (AMOLED) is a new type of active light-emitting display technology with the advantages of fast response speed, wide display color gamut, high contrast, low dynamic power consumption and wide viewing angle range. However, due to the materials and processes of AMOLED panels, for example, the parasitic capacitance formed by thin film field effect transistors (TFT), the non-uniformity of electrical parameters such as threshold voltage and mobility of TFTs in different positions, the AMOLED panel is prone to uneven brightness, which is called the Mura phenomenon / effect. Mura originally refers to the brightness unevenness of the display panel, and was later expanded to any brightness and color differences that can be perceived by the human eye. Since the Mura effect affects the user's visual experience, it needs to be eliminated, that is, Demura, otherwise the panel cannot meet the specifications of the end customer and can only be downgraded or scrapped.

[0003] AMOLED panels need to use various compensation technologies to eliminate undesirable phenomena such as horizontal stripes, patches, and color cast, solve the problem of uneven chromaticity / brightness of panel display, and improve the production yield of the panel. AMOLED panels are current-driven, and the display brightness of the pixel circuit is proportional to the current. The current is provided by TFT and is related to various characteristic parameters of TFT. Parameters that affect the current size include TFT mobility, threshold voltage, AMOLED drive voltage, and power supply voltage. According to different principles, AMOLED compensation is divided into two categories: internal compensation and external compensation. Among them, internal compensation refers to the development from the early 2T1C TFT structure to the complex structure of 7T2C by improving the pixel circuit. Obviously, this internal compensation method increases the complexity of circuit design, power consumption also increases accordingly, and the manufacturing process requirements of the panel are more stringent. Another internal compensation method refers to improving the display difference of the pixel circuit by measuring or sensing the change of the current of the pixel circuit, and adjusting the current, but it usually also faces the problem of inaccurate sensing current, resulting in the uneven brightness of the display panel caused by voltage drop and other reasons cannot be completely solved. Summary of the invention

[0004] The present invention provides a method for generating demura compensation data of an AMOLED panel and related equipment, the purpose of which is to solve the problem of uneven chromaticity / brightness displayed by the AMOLED panel and improve the production yield.

[0005] In order to achieve the above object, the present invention provides a method for generating demura compensation data of an AMOLED panel, comprising:

[0006] Step 1, respectively collecting brightness data corresponding to each pixel position on the target AMOLED display panel when inputting multiple levels of typical grayscales under multiple levels of typical display brightness values ​​and multiple levels of typical refresh rates;

[0007] Step 2: construct a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale. The brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data and the typical grayscale at each pixel position.

[0008] Step 3, counting the brightness data to obtain the average brightness of the target AMOLED display panel when each level of typical grayscale is input, and taking the average brightness as the standard brightness;

[0009] Step 4: for each brightness-grayscale mapping model, the standard brightness of the target AMOLED display panel at each typical grayscale is imported into the brightness-grayscale mapping model to obtain the actual expected grayscale of each pixel position;

[0010] Step 5, for each pixel position, solving the difference between the actual expected grayscale and the input typical grayscale to obtain the grayscale compensation value of each pixel position;

[0011] Step 6, construct a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolate and fit the compensation lookup table under atypical display brightness value, atypical refresh rate, and atypical grayscale to obtain a compensation lookup table for each pixel position under full display brightness value, full refresh rate, and full grayscale. The compensation lookup table includes the grayscale compensation values ​​of all pixel positions and is used to compensate for the grayscale of each pixel position.

[0012] Furthermore, before step 1, it also includes:

[0013] Calibrate the position of each pixel of the target AMOLED display panel to determine the position distribution of each pixel on the target AMOLED display panel;

[0014] Selecting a target display brightness value and a target refresh rate as a standard display brightness value and a standard refresh rate of a target AMOLED display panel;

[0015] The standard display brightness value and the standard refresh rate are used as initial parameters to set parameters of the target AMOLED display panel, thereby obtaining the target AMOLED display panel after parameter setting.

[0016] More specifically, step 1 includes:

[0017] The pixel circuit of the target AMOLED display panel after parameter setting is tested, and a set of nine-level typical grayscale samples of RGBW are simulated and generated;

[0018] The typical grayscale samples of each level are sequentially burned into the target AMOLED display panel after parameter setting through the display driver chip for display;

[0019] The brightness acquisition device is used to acquire the brightness data corresponding to each pixel position on the target AMOLED display panel at multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates.

[0020] Further, step 2 includes;

[0021] The brightness data is divided into a plurality of pixel distribution areas, and the brightness data is reversely used to establish brightness-grayscale mapping data of a plurality of pixel positions, wherein the pixel positions correspond to the pixel distribution areas one by one, and the brightness-grayscale mapping data includes the brightness data of each pixel position and a typical grayscale corresponding to the brightness data of each pixel position;

[0022] Combining the gamma characteristics of the brightness data, the brightness-grayscale mapping data is logarithmized to obtain logarithmic brightness data and logarithmic grayscale data;

[0023] With the logarithmic brightness data as input and the logarithmic grayscale data as output, multiple least squares polynomial fittings are performed to obtain the brightness-grayscale mapping model of each pixel position on the target AMOLED display panel.

[0024] Specifically, the brightness-grayscale mapping model is:

[0025]

[0026] Among them, GL represents the logarithmic grayscale data, L represents the logarithmic brightness data, K represents the polynomial coefficients of each order, (i, j) represents the pixel position index, and the subscript of K represents the polynomial order.

[0027] Specifically, the grayscale of each pixel position is compensated, including:

[0028] When the actual brightness of the pixel position at the input grayscale is greater than the standard brightness, negative compensation is performed on the input grayscale of the pixel position through the compensation lookup table to reduce the brightness of the pixel position to the standard brightness;

[0029] When the actual brightness of a pixel position at the input grayscale is less than the standard brightness, the input grayscale of the pixel position is positively compensated through the compensation lookup table to increase the brightness of the pixel position to the standard brightness.

[0030] The present invention also provides a Demura compensation data generating device, comprising:

[0031] An acquisition module, used for respectively acquiring brightness data corresponding to each pixel position on the target AMOLED display panel when inputting multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates;

[0032] The first construction module is used to construct a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale, and the brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data and the typical grayscale at each pixel position;

[0033] A statistical module is used to collect statistics on brightness data, obtain the average brightness of the target AMOLED display panel when each level of typical grayscale is input, and use the average brightness as the standard brightness;

[0034] An import module is used to import the standard brightness of the target AMOLED display panel at each typical grayscale into the brightness-grayscale mapping model for each brightness-grayscale mapping model, so as to obtain the actual expected grayscale of each pixel position;

[0035] A solution module is used to solve the difference between the actual expected grayscale and the input typical grayscale for each pixel position, and obtain the grayscale compensation value of each pixel position;

[0036] The second construction module is used to construct a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolate and fit the compensation lookup table under atypical display brightness values, atypical refresh rates, and atypical grayscales to obtain a compensation lookup table for the target AMOLED display panel under full display brightness values, full refresh rates, and full grayscales. The compensation lookup table includes grayscale compensation values ​​for all pixel positions and is used to compensate for the grayscale of each pixel position.

[0037] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method for generating Demura compensation data of an AMOLED panel is implemented.

[0038] The present invention also provides a terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the method for generating Demura compensation data for an AMOLED panel is implemented when the processor executes the computer program.

[0039] The above scheme of the present invention has the following beneficial effects:

[0040] The present invention collects the brightness data corresponding to each pixel position on the target AMOLED display panel when multiple typical grayscales are input under multiple typical display brightness values ​​and multiple typical refresh rates; constructs a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each typical grayscale; performs statistics on the brightness data to obtain the average brightness of the target AMOLED display panel when each typical grayscale is input, and uses the average brightness as the standard brightness; for each brightness-grayscale mapping model, imports the standard brightness of the target AMOLED display panel under each typical grayscale into the brightness-grayscale mapping model to obtain the actual expected grayscale of each pixel position; for each pixel position, solves the difference between the actual expected grayscale and the input typical grayscale to obtain the grayscale compensation value of each pixel position; constructs a compensation lookup table based on the grayscale compensation value of each pixel position, and calculates the grayscale compensation value of each pixel position under the atypical display brightness value and the atypical refresh rate. The compensation lookup table is interpolated and fitted at full display brightness value, full refresh rate and atypical grayscale to obtain a compensation lookup table of the target AMOLED display panel at full display brightness value, full refresh rate and full grayscale, and the compensation lookup table is used to compensate for the grayscale of each pixel position; compared with the prior art, the present invention fits the collected actual brightness information of different pixel positions with the input typical grayscale to obtain a mapping relationship between the brightness and grayscale of different pixel positions, and without changing the display panel pixel driving circuit and without electrically measuring the pixel circuit voltage / current, by generating and pre-storing a compensation lookup table of typical grayscale of multi-level color channels, and then adjusting the input of grayscale image data through the compensation lookup table to adjust the display brightness of each pixel position of the panel; compared with the prior art, the compensation lookup table can be used to perform grayscale compensation on all pixel positions of the AMOLED display panel one by one at any display brightness value and any refresh rate, thereby improving the brightness uniformity of the panel and improving the production yield.

[0041] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of a flow chart of an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of the structure of a compensation data generating device in an embodiment of the present invention;

[0044] Figure 3 Schematic diagram of the structure of a terminal device in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a locking connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] In view of the existing problems, the present invention provides a method for generating demura compensation data of an AMOLED panel and related equipment.

[0050] like Figure 1 As shown, an embodiment of the present invention provides a method for generating Demura compensation data of an AMOLED panel, comprising:

[0051] Step 1, respectively collecting brightness data corresponding to each pixel position on the target AMOLED display panel when inputting multiple levels of typical grayscales under multiple levels of typical display brightness values ​​and multiple levels of typical refresh rates;

[0052] Step 2: construct a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale. The brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data and the typical grayscale at each pixel position.

[0053] Step 3, counting the brightness data to obtain the average brightness of the target AMOLED display panel when each level of typical grayscale is input, and taking the average brightness as the standard brightness;

[0054] Step 4: for each brightness-grayscale mapping model, the standard brightness of the target AMOLED display panel at each typical grayscale is imported into the brightness-grayscale mapping model to obtain the actual expected grayscale of each pixel position;

[0055] Step 5, for each pixel position, solving the difference between the actual expected grayscale and the input typical grayscale to obtain the grayscale compensation value of each pixel position;

[0056] Step 6, constructing a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolating and fitting the compensation lookup table under atypical display brightness value, atypical refresh rate, and atypical grayscale, to obtain a compensation lookup table for the target AMOLED display panel under full display brightness value, full refresh rate, and full grayscale. The compensation lookup table includes grayscale compensation values ​​of all pixel positions and is used to compensate for the grayscale of each pixel position.

[0057] Most preferably, before step 1, the method further comprises:

[0058] Calibrate the position of each pixel of the target AMOLED display panel to determine the position distribution of each pixel on the target AMOLED display panel, so as to achieve a one-to-one correspondence between brightness data and pixel position;

[0059] Selecting a target display brightness value and a target refresh rate as a standard display brightness value and a standard refresh rate of a target AMOLED display panel;

[0060] The standard display brightness value and the standard refresh rate are used as initial parameters to set parameters of the target AMOLED display panel, thereby obtaining the target AMOLED display panel after parameter setting.

[0061] In the embodiments of the present invention, the typical grayscale, typical display brightness value DBV and typical refresh rate are based on the DBV and refresh rate parameters of different types of screens in common states. The modified DBV and refresh rate in other environments are called atypical DBV and refresh rate. For example, the typical DBV is 3FF, the refresh rate is 60Hz, and the typical grayscale can be 16, 32, 64, 128, 192, 224, etc.

[0062] The target AMOLED display panel is generally provided with manual or adaptive adjustment of the screen display brightness, that is, the screen brightness of the display panel needs to be highly adapted to the external environment. When the external environment light becomes dim, the target AMOLED display panel also needs to appropriately reduce the brightness; when the external light becomes stronger, the target AMOLED display panel also appropriately increases the brightness to obtain a better visual effect, and the parameter for controlling the overall brightness of the target AMOLED display panel is the display brightness value DBV. Adjusting the display brightness value will affect the voltage and current of the loudness circuit, so it is necessary to introduce the display brightness value; therefore, in an embodiment of the present invention, different display brightness values ​​are set for the target AMOLED display panel, and the accuracy is generally 8 / 10 / 12 bits. The display brightness value with better uniformity can be selected as the standard display brightness value according to the actual working conditions. Generally speaking, the larger the display brightness value, the better the uniformity; other display brightness values ​​select several display brightness values ​​as typical display brightness value groups. For example, the commonly used display brightness value is DBV 3FF, and the commonly used refresh rate is 60Hz;

[0063] Depending on the application scenario, the display panel playback parameters of the target AMOLED display panel may include changes in the refresh rate, which also affects the display brightness uniformity. Experiments have shown that the panel uniformity difference under different refresh rates fluctuates around 1%. In order to maintain the display effect of the panel under application scenarios with different refresh rates, the embodiment of the present invention fixes the refresh rate of the target AMOLED display panel, and takes the commonly used 60 / 120Hz refresh rate as the standard refresh rate. First, the standard display brightness value and the standard refresh rate are set as initial parameters.

[0064] Most preferably, step 1 comprises:

[0065] Simulate the pixel circuit of the target AMOLED display panel after parameter setting to generate a set of nine typical grayscale samples of RGBW;

[0066] The typical grayscale samples of each level are sequentially input into the target AMOLED display panel after parameter setting through the display driver chip for display;

[0067] The brightness acquisition device is used to respectively acquire the brightness data corresponding to each pixel position on the target AMOLED display panel at multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates.

[0068] In the embodiment of the present invention, the nine-level typical grayscale samples are image samples of nine-level typical grayscales generated by simulation software. In an environment without interference from other light sources, the nine-level typical grayscale image samples are sequentially imported into the target AMOLED display panel after parameter setting through the display driver chip to light up the panel. Assuming that the image sample is X:

[0069] X=[Gray_L1,Gray_L2,Gray_L3,Gray_L4,Gray_L5,Gray_L6,Gray_L7,Gray_L8,Gray_L9]

[0070] The brightness data corresponding to each pixel position on the target AMOLED display panel when the above typical grayscale is input is collected by a brightness collection device, and are recorded as [L1(i,j), L2(i,j), L3(i,j), L4(i,j), L5(i,j), L6(i,j), L7(i,j), L8(i,j), L9(i,j)]. Wherein, (i,j) represents the index number of each pixel position of the target AMOLED display panel;

[0071] By performing pixel calibration through the brightness acquisition device, the brightness data of the target AMOLED display panel when different typical grayscales are input and the initial brightness data distribution are obtained.

[0072] It should be noted that the brightness acquisition equipment includes but is not limited to a brightness acquisition meter, an industrial camera, a high-precision CCD camera, etc. The embodiment of the present invention adopts a high-precision CCD camera.

[0073] In order to improve the brightness uniformity of the target AMOLED display panel, it is necessary to make the luminous brightness values ​​of all pixels of the target AMOLED display panel as close or equal as possible when the same grayscale is input. To this end, it is necessary to construct a mapping model between the pixel position of the target AMOLED display panel between the input grayscale and the output brightness. The construction method is shown in step 2.

[0074] Most preferably, step 2 comprises:

[0075] The brightness data is divided into a number of pixel distribution areas, and the brightness data is reversely used to establish brightness-grayscale mapping data of a number of pixel positions, where the pixel positions correspond to the pixel distribution areas one by one, and the brightness-grayscale mapping data includes the brightness data of each pixel position and the typical grayscale corresponding to the brightness data of each pixel position, so as to calculate the brightness uniformity of each pixel position of the target AMOLED display panel when each typical grayscale is input;

[0076] Combined with the gamma characteristics of the brightness data, the brightness-grayscale mapping data is logarithmized to obtain logarithmic brightness data and logarithmic grayscale data. Logarithmization is the inverse gamma transformation.

[0077] With the logarithmic brightness data as input and the logarithmic grayscale data as output, multiple least squares polynomial fittings are performed to obtain the brightness-grayscale mapping model of each pixel position on the target AMOLED display panel. In an embodiment of the present invention, the polynomial fitting parameters of the brightness-grayscale mapping model at different pixel positions are different.

[0078] In an embodiment of the present invention, the brightness data is divided into M×N pixel distribution areas, which correspond one-to-one to M×N pixel positions, and the brightness data is reversely used to establish brightness-grayscale mapping data of M×N pixel positions; the number of least squares polynomial fitting is 3.

[0079] Most preferably, with pixel position as a unit, the brightness-grayscale mapping model of the target AMOLED display panel is:

[0080]

[0081] Among them, GL represents the logarithmic grayscale data, L represents the logarithmic brightness data, K represents the polynomial coefficients of each order, (i, j) represents the pixel position index, and the subscript of K represents the polynomial order.

[0082] In the embodiment of the present invention, the brightness data is divided into distribution areas of M×N pixels, and the average minimum brightness value / average maximum brightness value×100% in units of distribution areas is the brightness uniformity of the target AMOLED display panel when the grayscale is input.

[0083] It should be noted that the mapping model parameters at different pixel positions are different, which can actually reflect the differences in circuit characteristics such as resistance of the pixel circuit of the display panel due to process, position, etc., which ultimately leads to differences in pixel luminous brightness.

[0084] Most preferably, step 3 comprises:

[0085] Calculate the average brightness of the target AMOLED display panel when inputting each level of typical grayscale through brightness data;

[0086] The average brightness of the target AMOLED display panel when each level of typical grayscale is input is used as the standard brightness of the target AMOLED display panel when each level of typical grayscale is input.

[0087] In the embodiment of the present invention, the standard brightness under different input typical grayscales is determined in step 3, and the standard brightness is brought into the brightness-grayscale mapping model corresponding to each pixel position in step 4, so as to obtain the actual expected grayscale of the pixel position.

[0088] Most preferably, the expression for solving the difference OG between the actual expected grayscale and the input typical grayscale is:

[0089] OG (i,j) =EG (i,j) -TG (i,j)

[0090] Wherein, EG represents the actual desired grayscale, and TG represents the input typical grayscale.

[0091] When the pixel circuit displays a typical grayscale of a certain input, the compensation value of the corresponding pixel position in the compensation lookup table is directly added to adjust the pixel output brightness, thereby achieving the effect of improving display uniformity.

[0092] In an embodiment of the present invention, when the input grayscale is an atypical grayscale, the pixel driving circuit combines the compensation lookup table stored in the RAM and uses the nearest neighbor interpolation method to interpolate the compensation lookup table for each pixel position under different typical grayscales to obtain the compensation lookup table for each pixel position under the full grayscale, and corresponding position compensation can be directly performed for different pixel positions.

[0093] Since the pixel circuit of the target AMOLED display panel is generally composed of three color sub-pixel circuits of R, G, and B, and the sub-pixel circuits of different colors have different materials, different processes, different luminous efficiencies, and different combination arrangements, resulting in the grayscale luminescence changes of the three primary colors being different from the sub-pixels, the embodiment of the present invention saves all the grayscale compensation lookup tables of the RGBW pixel circuits in the four luminescence scenarios, so that when dealing with different sub-pixel luminescence situations, the display driver chip can perform corresponding compensation by calling different compensation lookup tables.

[0094] Since AMOLED uses display brightness value DBV to represent brightness control, it generally adopts multi-stage adjustment (such as 1024 stages in total when the display brightness value adjustment accuracy is 10bit). In order to achieve better grayscale transition at low brightness, the display brightness value is divided into multiple intervals. AMOLED controls the display brightness value of the entire display panel by adopting a segmented Gamma curve. Such changes in multi-segment adjustment may cause changes in the Gamma curve of the display panel. Therefore, in the embodiment of the present invention, in order to meet the parameter adjustment of all display brightness values ​​and save the storage overhead of the compensation lookup table as much as possible, it is necessary to divide the display brightness value into typical display brightness values ​​and other display brightness values. In this way, the embodiment of the present invention can obtain a compensation lookup table for each pixel position under full display brightness value and full grayscale.

[0095] In order to maintain the display effect of the target AMOLED display panel in application scenarios with different refresh rates, a compensation lookup table at full refresh rate and full grayscale is constructed in the embodiment of the invention. In this way, in each application scenario, there is no need to additionally store the compensation lookup table at different refresh rates, which saves the storage resources of the pixel driver chip while achieving the display brightness uniformity of the target AMOLED display panel.

[0096] In the embodiment of the present invention, in order to improve the compensation accuracy, a dither algorithm is used to increase the accuracy of the compensation value and the input grayscale from 8 bits to 10 bits, and then restore the accuracy of the grayscale value of the compensated pixel position to 8 bits.

[0097] Specifically, the grayscale of each pixel position is compensated, including:

[0098] When the actual brightness of the pixel position at the input grayscale is greater than the standard brightness, negative compensation is performed on the input grayscale of the pixel position through the compensation lookup table to reduce the brightness of the pixel position to the standard brightness;

[0099] When the actual brightness of a pixel position at the input grayscale is less than the standard brightness, the input grayscale of the pixel position is positively compensated through the compensation lookup table to increase the brightness of the pixel position to the standard brightness.

[0100] The embodiment of the present invention transmits all the generated compensation lookup table and fitting parameters to the memory RAM / FALSH of the display driver chip through the data line. In the actual compensation application, the compensation lookup table under the standard display brightness value, standard refresh rate and other parameters is read to obtain the compensation grayscale value of each pixel position of the full screen when the grayscale is input. The compensation steps of various grayscales are as follows:

[0101] Read the current display brightness value of the AMOLED display panel. If the current display brightness value is the standard display brightness value, directly read the compensation lookup table to perform grayscale compensation. If the current display brightness value is the non-standard display brightness value, further determine whether the current display brightness value is the typical display brightness value. If so, directly read the fitting parameters corresponding to the typical display brightness value, and perform fitting operation with the compensation lookup table data of the standard display brightness value to obtain the compensation lookup table corresponding to the typical display brightness value. If the current display brightness value does not belong to the typical display brightness value, the typical display brightness value closest to the current display brightness value is used as a reference compensation, and the compensation value in the compensation lookup table corresponding to the closest typical display brightness value is selected as the grayscale compensation value under the current display brightness value, and then the subsequent grayscale compensation work is performed.

[0102] Read the current refresh rate of the AMOLED display panel. If the current refresh rate is the standard refresh rate, directly read the compensation lookup table to perform grayscale compensation. If the current refresh rate is a non-standard refresh rate, further determine the refresh rate fitting parameters corresponding to the current refresh rate, directly read the fitting parameters of the current refresh rate and the typical refresh rate, perform fitting calculations with the compensation lookup table of the standard refresh rate, obtain the compensation lookup table corresponding to the refresh rate, and then perform the subsequent grayscale compensation.

[0103] After obtaining the compensation lookup table under the current display brightness value and the current refresh rate, the input grayscale of the pixel circuit is detected. When the input grayscale is 0, that is, the input grayscale is black, no compensation is required and 0 is directly output; when the input grayscale is a non-0 standard grayscale, the grayscale compensation value of the pixel position is directly added; when the input grayscale is an intermediate grayscale, the grayscale compensation value of the intermediate grayscale is obtained by fitting the compensation lookup table of the adjacent typical grayscale. Taking the intermediate grayscale 88 as an example, the intermediate grayscale value is between the typical grayscale

[6496] range and is closer to the typical grayscale 96. The compensation lookup table for the intermediate grayscale is based on the compensation lookup table of the typical grayscale 96, and is directly multiplied by 88 / 96.

[0104] The embodiment of the present invention collects the brightness data corresponding to each pixel position on the target AMOLED display panel when multiple typical grayscales are input under multiple typical display brightness values ​​and multiple typical refresh rates; constructs a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each typical grayscale; performs statistics on the brightness data to obtain the average brightness of the target AMOLED display panel when each typical grayscale is input, and uses the average brightness as the standard brightness; for each brightness-grayscale mapping model, imports the standard brightness of the target AMOLED display panel under each typical grayscale into the brightness-grayscale mapping model to obtain the actual expected grayscale of each pixel position; for each pixel position, solves the difference between the actual expected grayscale and the input typical grayscale to obtain the grayscale compensation value of each pixel position; constructs a compensation lookup table based on the grayscale compensation value of each pixel position, and calculates the grayscale compensation value of each pixel position in the atypical display brightness value and the atypical refresh rate. The compensation lookup table is interpolated and fitted at full display brightness value, full refresh rate and atypical grayscale to obtain a compensation lookup table of the target AMOLED display panel at full display brightness value, full refresh rate and full grayscale, and the compensation lookup table is used to compensate for the grayscale of each pixel position; compared with the prior art, the embodiment of the present invention fits the collected actual brightness information of different pixel positions with the input typical grayscale to obtain a mapping relationship between the brightness and grayscale of different pixel positions, and without changing the display panel pixel driving circuit and without electrically measuring the pixel circuit voltage / current, by generating and pre-storing a compensation lookup table of typical grayscales of multi-level color channels, and then adjusting the input of grayscale image data through the compensation lookup table to adjust the display brightness of each pixel position of the panel; compared with the prior art, the compensation lookup table can be used to perform grayscale compensation on all pixel positions of the AMOLED display panel one by one at any display brightness value and any refresh rate, thereby improving the brightness uniformity of the panel and improving the production yield.

[0105] The embodiment of the present invention also provides a device for generating demura compensation data, such as Figure 2 As shown, the compensation data generating device 100 comprises:

[0106] The acquisition module 101 is used to respectively acquire brightness data corresponding to each pixel position on the target AMOLED display panel when multiple typical grayscales are input under multiple typical display brightness values ​​and multiple typical refresh rates;

[0107] A first construction module 102 is used to construct a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale, wherein the brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data and the typical grayscale at each pixel position;

[0108] A statistics module 103 is used to collect statistics on the brightness data, obtain the average brightness of the target AMOLED display panel when each level of typical grayscale is input, and use the average brightness as the standard brightness;

[0109] An import module 104 is used to import the standard brightness of the target AMOLED display panel at each typical grayscale into the brightness-grayscale mapping model for each brightness-grayscale mapping model, so as to obtain the actual expected grayscale of each pixel position;

[0110] A solution module 105 is used to solve the difference between the actual expected grayscale and the input typical grayscale for each pixel position, and obtain the grayscale compensation value of each pixel position;

[0111] The second construction module 106 is used to construct a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolate and fit the compensation lookup table under atypical display brightness values, atypical refresh rates, and atypical grayscales to obtain a compensation lookup table for the target AMOLED display panel under full display brightness values, full refresh rates, and full grayscales. The compensation lookup table includes grayscale compensation values ​​for all pixel positions and is used to compensate for the grayscale of each pixel position.

[0112] The compensation data generating device 100 further includes:

[0113] A calibration module, used to calibrate the position of each pixel of the target AMOLED display panel to determine the position distribution of each pixel on the target AMOLED display panel;

[0114] A selection module, used for selecting a target display brightness value and a target refresh rate as a standard display brightness value and a standard refresh rate of a target AMOLED display panel;

[0115] The setting module is used to set the parameters of the target AMOLED display panel by taking the standard display brightness value and the standard refresh rate as initial parameters to obtain the target AMOLED display panel after the parameters are set.

[0116] Among them, the above-mentioned acquisition module 101 is specifically used to simulate the pixel circuit of the target AMOLED display panel after parameter setting, and generate a set of nine-level typical grayscale samples of RGBW; input the typical grayscale samples of each level in sequence into the target AMOLED display panel after parameter setting through the display driver chip for display; and use the brightness acquisition device to respectively acquire the brightness data corresponding to each pixel position on the target AMOLED display panel at multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates.

[0117] The acquisition module 101 includes:

[0118] The simulation submodule is used to prepare the pixel circuit of the target AMOLED display panel after parameter setting, and simulate and generate a set of nine-level typical grayscale samples of RGBW;

[0119] An input submodule, used to sequentially input each level of typical grayscale samples to the target AMOLED display panel after parameter setting through a display driver chip for display;

[0120] The acquisition submodule is used to use the brightness acquisition device to respectively acquire the brightness data corresponding to each pixel position on the target AMOLED display panel at multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates.

[0121] Among them, the above-mentioned first construction module 102 is specifically used to divide the brightness data into several pixel distribution areas, and reversely establish brightness-grayscale mapping data of several pixel positions from the brightness data. The pixel positions correspond to the pixel distribution areas one by one, and the brightness-grayscale mapping data includes the brightness data of each pixel position and the typical grayscale corresponding to the brightness data of each pixel position; in combination with the gamma characteristics of the brightness data, the brightness-grayscale mapping data is logarithmized to obtain logarithmic brightness data and logarithmic grayscale speed data; with the logarithmic brightness data as input and the logarithmic grayscale data as output, multiple least squares polynomial fittings are performed to obtain the brightness-grayscale mapping model of each pixel position on the target AMOLED display panel.

[0122] The first building block 102 includes:

[0123] A division submodule, used to divide the brightness data into a number of pixel distribution areas, and reversely establish brightness-grayscale mapping data of a number of pixel positions from the brightness data, wherein the pixel positions correspond to the pixel distribution areas one by one, and the brightness-grayscale mapping data includes brightness data of each pixel position and a typical grayscale corresponding to the brightness data of each pixel position;

[0124] The logarithmization submodule is used to logarithmize the brightness-grayscale mapping data in combination with the gamma characteristics of the brightness data to obtain logarithmic brightness data and logarithmic grayscale speed data;

[0125] The fitting submodule is used to take the logarithmic brightness data as input and the logarithmic grayscale data as output, perform multiple least squares polynomial fittings, and obtain the brightness-grayscale mapping model of each pixel position on the target AMOLED display panel.

[0126] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0127] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0128] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, a method for generating Demura compensation data for an AMOLED panel is implemented.

[0129] An embodiment of the present application provides a computer program product. When the computer program product runs on a mobile terminal, the mobile terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0130] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the construction device / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, U disk, mobile hard disk, disk or optical disk, etc. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0131] The embodiment of the present invention also provides a terminal device, such as Figure 3 As shown, the terminal device D10 of this embodiment includes: at least one processor D100 ( Figure 3 Only one processor is shown in the figure), a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, wherein the processor D100 implements the steps in any of the above-mentioned method embodiments when executing the computer program D102. Alternatively, the processor D100 implements the functions of each module / unit in the above-mentioned device embodiments when executing the computer program D102.

[0132] The terminal device D10 may be a computing device such as a desktop computer, a notebook, a PDA, a server, a server cluster, a cloud server, etc. The terminal device may include, but is not limited to, a processor D100 and a memory D101. Those skilled in the art will appreciate that Figure 3 This is only an example of the terminal device D10 and does not constitute a limitation on the terminal device D10. The terminal device D10 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0133] The processor D100 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0134] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may also be an external storage device of the terminal device D10, such as a plug-in hard disk, a smart memory card (SMC, SmartMedia Card), a secure digital (SD, Secure Digital) card, a flash card (Flash Card), etc. equipped on the terminal device D10. Further, the memory D101 may also include both an internal storage unit and an external storage device of the terminal device D10. The memory D101 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program, etc. The memory D101 may also be used to temporarily store data that has been output or is to be output.

[0135] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0136] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0137] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for generating demura compensation data for an AMOLED panel, characterized in that: include: Step 1, respectively collecting brightness data corresponding to each pixel position on the target AMOLED display panel when inputting multiple levels of typical grayscales under multiple levels of typical display brightness values ​​and multiple levels of typical refresh rates; Step 2, constructing a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale, wherein the brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data at each pixel position and the typical grayscale; Step 3, performing statistics on the brightness data to obtain the average brightness of the target AMOLED display panel when each level of typical grayscale is input, and using the average brightness as the standard brightness; Step 4: for each brightness-grayscale mapping model, the standard brightness of the target AMOLED display panel at each typical grayscale is imported into the brightness-grayscale mapping model to obtain the actual expected grayscale of each pixel position; Step 5, for each pixel position, solving the difference between the actual expected grayscale and the input typical grayscale to obtain a grayscale compensation value for each pixel position; Step 6, constructing a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolating and fitting the compensation lookup table under atypical display brightness value, atypical refresh rate, and atypical grayscale, to obtain a compensation lookup table for the target AMOLED display panel under full display brightness value, full refresh rate, and full grayscale, wherein the compensation lookup table includes the grayscale compensation values ​​of all pixel positions and is used to compensate for the grayscale of each pixel position.

2. The method for generating demura compensation data of an AMOLED panel according to claim 1, characterized in that: Before step 1, the method further includes: Calibrate the position of each pixel of the target AMOLED display panel to determine the position distribution of each pixel on the target AMOLED display panel; Selecting a target typical display brightness value and a target typical refresh rate as a standard display brightness value and a standard refresh rate of the target AMOLED display panel; The target AMOLED display panel is configured using the standard display brightness value and the standard refresh rate as initial parameters to obtain a target AMOLED display panel after parameter setting.

3. The method for generating demura compensation data for an AMOLED panel according to claim 2, characterized in that: The step 1 comprises: The pixel circuit of the target AMOLED display panel after parameter setting is tested. First, a set of nine-level typical grayscale samples of RGBW are simulated and generated; The typical grayscale samples of each level are sequentially burned into the target AMOLED display panel after parameter setting through the display driver chip for display; The brightness acquisition device is used to acquire the brightness data corresponding to each pixel position on the target AMOLED display panel at multiple typical grayscales after parameter setting under multiple typical display brightness values ​​and multiple typical refresh rates.

4. The method for generating demura compensation data of an AMOLED panel according to claim 3, characterized in that: The step 2 comprises: Dividing the brightness data into a plurality of pixel distribution areas, and reversely establishing brightness-grayscale mapping data of a plurality of pixel positions from the brightness data, wherein the pixel positions correspond to the pixel distribution areas one by one, and the brightness-grayscale mapping data includes brightness data of each pixel position and a typical grayscale corresponding to the brightness data of each pixel position; Combining the gamma characteristics of the brightness data, logarithmizing the brightness-grayscale mapping data to obtain logarithmic brightness data and logarithmic grayscale data; The logarithmic brightness data is used as input and the logarithmic grayscale data is used as output, and multiple least squares polynomial fittings are performed to obtain a brightness-grayscale mapping model of each pixel position on the target AMOLED display panel.

5. The method for generating demura compensation data for an AMOLED panel according to claim 4, characterized in that: The brightness-grayscale mapping model is: Among them, GL represents the logarithmic grayscale data, L represents the logarithmic brightness data, K represents the polynomial coefficients of each order, (i, j) represents the pixel position index, and the subscript of K represents the polynomial order.

6. The method for generating demura compensation data for an AMOLED panel according to claim 5, characterized in that: Compensate the grayscale of each pixel position, including: When the actual brightness of the pixel position at the input grayscale is greater than the standard brightness, negative compensation is performed on the input grayscale of the pixel position through the compensation lookup table to reduce the brightness of the pixel position to the standard brightness; When the actual brightness of the pixel position at the input grayscale is less than the standard brightness, the input grayscale of the pixel position is positively compensated through the compensation lookup table to increase the brightness of the pixel position to the standard brightness.

7. A demura compensation data generating device, characterized in that: include: An acquisition module, used for respectively acquiring brightness data corresponding to each pixel position on the target AMOLED display panel when inputting multiple typical grayscales under multiple typical display brightness values ​​and multiple typical refresh rates; A first construction module is used to construct a brightness-grayscale mapping model for each pixel position on the target AMOLED display panel according to the mapping relationship between the brightness data and each level of typical grayscale, wherein the brightness-grayscale mapping model is used to characterize the corresponding relationship between the brightness data at each pixel position and the typical grayscale; A statistical module, used for performing statistics on the brightness data, obtaining a brightness average of the target AMOLED display panel when each level of typical grayscale is input, and using the brightness average as a standard brightness; An import module, for importing the standard brightness of the target AMOLED display panel at each level of typical grayscale into the brightness-grayscale mapping model, so as to obtain the actual expected grayscale of each pixel position; A solution module, used for solving the difference between the actual expected grayscale and the input typical grayscale for each pixel position, to obtain a grayscale compensation value for each pixel position; The second construction module is used to construct a compensation lookup table based on the grayscale compensation value of each pixel position, and interpolate and fit the compensation lookup table under atypical display brightness value, atypical refresh rate, and atypical grayscale to obtain a compensation lookup table for each pixel position under full display brightness value, full refresh rate, and full grayscale. The compensation lookup table includes the grayscale compensation values ​​of all pixel positions and is used to compensate for the grayscale of each pixel position.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for generating Demura compensation data for an AMOLED panel according to any one of claims 1 to 6 is implemented.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for generating Demura compensation data for an AMOLED panel according to any one of claims 1 to 6 is implemented.

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