Brightness compensation method of display panel and display panel

Abstract

The invention discloses a brightness compensation method of a display panel and the display panel. The brightness compensation method of the display panel comprises the following steps: respectively lightening and testing the display panel according to at least two binding point display parameters; for the test display panel which is lightened under any binding point display parameter, respectively exposing the test display panel by adopting at least two different exposure times, and obtaining the optical brightness of the test display panel through an optical camera after each exposure; and compensating the to-be-compensated display panel according to the optical brightness of the test display panel obtained each time under each binding point display parameter and the current display parameter of the to-be-compensated display panel. The accuracy of the compensation data corresponding to the binding point display parameters is improved through data fitting, so that the compensation accuracy is improved when the to-be-compensated display panel is compensated according to the current display parameters of the to-be-compensated display panel and the compensation data corresponding to the binding point display parameters.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a brightness compensation method for a display panel and a display panel. Background Art

[0002] Organic Light-Emitting Diode (OLED) display panels have a problem of poor brightness uniformity when displaying, namely, the mura phenomenon.

[0003] In the prior art, when compensating for mura, the compensation effect is poor. Summary of the invention

[0004] The invention provides a brightness compensation method of a display panel and a display panel, so as to improve the problem of poor mura compensation effect.

[0005] According to one aspect of the present invention, a brightness compensation method for a display panel is provided, comprising:

[0006] Lighting up the test display panel respectively with at least two binding point display parameters;

[0007] For a test display panel lit under any of the binding point display parameters, the test display panel is exposed using at least two different exposure times, and the optical brightness of the test display panel is acquired by an optical camera after each exposure;

[0008] The display panel to be compensated is compensated according to the optical brightness of the test display panel acquired each time under each binding point display parameter and the current display parameters of the display panel to be compensated.

[0009] Optionally, the display parameters include display brightness levels and grayscale values, and the compensating the display panel to be compensated according to the optical brightness of the test display panel obtained each time under each binding point display parameter and the current display parameters of the display panel to be compensated includes:

[0010] For any binding point display parameter, generating compensation data corresponding to the binding point display parameter according to the optical brightness of the test display panel acquired each time under the binding point display parameter and the actual brightness of the test display panel under the binding point display parameter;

[0011] The display panel to be compensated is compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point.

[0012] Optionally, generating compensation data corresponding to the binding point display parameter according to the optical brightness of the test display panel acquired each time under the binding point display parameter and the actual brightness of the test display panel under the binding point display parameter includes:

[0013] Generate a comprehensive brightness of the test display panel according to the optical brightness of the test display panel obtained each time;

[0014] Compensation data corresponding to the binding point display parameters are generated according to the comprehensive brightness of the test display panel and the actual brightness under the binding point display parameters.

[0015] Optionally, generating the comprehensive brightness of the test display panel according to the optical brightness of the test display panel obtained each time includes:

[0016] Determining a bright area and a dark area of ​​the test display panel according to an optical brightness of the test display panel obtained after exposing the display panel using a first exposure time;

[0017] Determine a weight coefficient corresponding to the optical brightness of the bright area and the optical brightness of the dark area of ​​the test display panel obtained each time, according to the optical brightness of the bright area and the optical brightness of the dark area of ​​the test display panel obtained each time and the actual brightness of the test display panel under the binding point display parameters;

[0018] Determining the integrated brightness of the test display panel according to the brightness function of the bright area and the brightness function of the dark area;

[0019] Wherein, the brightness function W of the bright area satisfies:

[0020] n is the total number of times the optical brightness of the test display panel is obtained, A i is the weight coefficient corresponding to the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, W i is the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, i is an integer greater than or equal to 1 and less than or equal to n,

[0021] The brightness function D of the dark area satisfies:

[0022] B i is the weight coefficient corresponding to the optical brightness of the dark area of ​​the test display panel obtained for the i-th time, D i is the optical brightness of the dark area of ​​the test display panel obtained for the i-th time,

[0023] Optionally, the test display panel includes a plurality of sub-pixels, the comprehensive brightness of the test display panel includes the comprehensive brightness of each sub-pixel, and after generating the comprehensive brightness of the test display panel according to the optical brightness of the test display panel acquired each time, the method further includes:

[0024] The integrated brightness of a preset sub-pixel is set to a fixed brightness value; wherein the preset sub-pixel is a pixel whose integrated brightness is less than or equal to a brightness threshold.

[0025] Optionally, the integrated brightness of any sub-pixel adjacent to the preset sub-pixel is used as the fixed brightness value, or the average value of the integrated brightness of multiple sub-pixels adjacent to the preset sub-pixel is used as the fixed brightness value.

[0026] Optionally, compensating the display panel to be compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point includes:

[0027] When there is a reference display parameter in each of the binding point display parameters, the compensation data corresponding to the reference display parameter is used as the compensation data of the display panel to be compensated; the reference display parameter is the same as the current display parameter of the display panel to be compensated; when there is no reference display parameter in all the binding point display parameters, the compensation data of the display panel to be compensated is determined by interpolation calculation;

[0028] The display panel to be compensated is compensated according to the compensation data of the display panel to be compensated.

[0029] Optionally, when the test display panel is exposed using at least two different exposure times respectively, the latter exposure time is greater than the former exposure time;

[0030] Optionally, the first exposure time is between 10S and 20S;

[0031] Optionally, the i-th exposure time is 0.8*i times to 1.2*i times the first exposure time, where i is an integer greater than or equal to 2.

[0032] Optionally, the brightness compensation method of the display panel further includes:

[0033] Each time the test display panel is exposed, the optical camera is controlled to simultaneously turn on the digital gain and the analog gain.

[0034] According to another aspect of the present invention, a display panel is provided, which is controlled by the brightness compensation method of the display panel described in the above aspect.

[0035] The embodiment of the present invention sets multiple exposure times to obtain optical brightness corresponding to the multiple exposure times, and performs data fitting on the optical brightness corresponding to the multiple exposure times, so that relatively real brightness data can be collected for an overly bright or overly dark screen that exceeds the dynamic range of the optical camera, and the compensation data corresponding to the binding point display parameters are determined according to the fitted optical brightness. The accuracy of the compensation data corresponding to the binding point display parameters is improved through data fitting, and then when the display panel to be compensated is compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the binding point display parameters, the accuracy of the compensation is improved.

[0036] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A flow chart of a brightness compensation method for a display panel provided by an embodiment of the present invention;

[0039] Figure 2 A flowchart of another brightness compensation method for a display panel provided by an embodiment of the present invention;

[0040] Figure 3 A flowchart of another brightness compensation method for a display panel provided by an embodiment of the present invention;

[0041] Figure 4 A flowchart of another brightness compensation method for a display panel provided by an embodiment of the present invention;

[0042] Figure 5 is an optical brightness diagram of the test display panel obtained by conventional exposure time under the tied point display parameters;

[0043] Figure 6 is an optical brightness diagram of the test display panel obtained by fitting the optical brightness through multiple exposures under the tied point display parameters;

[0044] Figure 7 is the compensation distribution diagram obtained by a regular exposure time under the current display parameters;

[0045] Figure 8is a compensation distribution diagram obtained by fitting the optical brightness through multiple exposures under the current display parameters;

[0046] Fig. 9 A relative error comparison diagram of the comprehensive optical brightness of the test display panel obtained by single exposure and double exposure;

[0047] Fig.10 A schematic diagram of the structure of a system for performing brightness compensation on a display panel provided by an embodiment of the present invention;

[0048] Fig.11 A principle block diagram of a driving chip, a memory and a display panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] As described in the background technology, in the prior art, when compensating for mura, the compensation effect is poor. The inventors have found that the reason is that the optical brightness of the display panel obtained under low brightness and low grayscale is inaccurate. Specifically, when compensating for mura, it is necessary to obtain the optical brightness of the display panel and calculate the mura compensation data through the optical brightness. However, under low brightness and low grayscale, when the brightness of the display panel is low, when the brightness of the display panel is obtained using a conventional exposure time, the brightness of a part of the area with low brightness is obtained inaccurately, resulting in poor mura compensation effect.

[0052] In view of the above technical problems, an embodiment of the present invention provides a brightness compensation method for a display panel, which obtains the optical brightness of the display panel by performing data fitting through multiple exposures, thereby improving the accuracy of the acquired brightness of the display panel and further improving the accuracy of mura compensation.

[0053] Figure 1 A flowchart of a brightness compensation method for a display panel provided by an embodiment of the present invention, referring to Figure 1 , the method comprising:

[0054] S110: Light up the test display panels respectively with at least two binding point display parameters.

[0055] The test display panel and the display panel to be compensated can be products of the same batch, and the performance parameters are the same, so as to ensure that the display panel to be compensated can be compensated according to the optical brightness obtained from the test display panel. The display parameters include display brightness level and grayscale value, and at least two different display parameters are arbitrarily selected from multiple display parameters as binding point display parameters. When one of the display brightness level and the grayscale value is different, the display parameters are deemed to be different. Display devices such as mobile phones and computers usually include a brightness adjustment button, and the user uses the brightness adjustment button to change the input display brightness level. The display brightness level is also called the display brightness value (Display Brightness Value, DBV). Among them, each display brightness level can correspond to a display brightness of the maximum grayscale in the display panel. After the display brightness corresponding to the maximum grayscale in the display panel changes, the display brightness corresponding to other grayscales will also change.

[0056] Because the display panel is prone to mura problems at a smaller grayscale at a lower display brightness level, the binding point display parameter can select a display parameter with a smaller display brightness level and grayscale value. Optionally, two binding point display parameters are set in this embodiment, one is 32 grayscales at 5nit, and the other binding point display parameter is 64 grayscales at 5nit.

[0057] When the display brightness level is constant, the grayscale value and the data voltage correspond one to one. The display panel includes multiple sub-pixels. For any binding point display parameter, all sub-pixels of the test display panel are controlled to write the data voltage corresponding to the binding point display parameter, so as to control each sub-pixel in the test display panel to light up at the same display brightness level and grayscale, thereby realizing lighting up the test display panel with the binding point display parameter.

[0058] S120: for the test display panel lit under each binding point display parameter, respectively expose the test display panel using at least two different exposure times, and obtain the optical brightness of the test display panel through an optical camera after each exposure.

[0059] The optical brightness of the test display panel can be understood as the optical brightness of each sub-pixel in the test display panel. After the test display panel is lit under any binding point display parameter, the optical brightness corresponding to the test display panel under each exposure time is obtained by setting different exposure times of the optical camera. The optical camera can be an optical charge coupled device image sensor (CCD), which uses the CCD to take a picture of the lit test display panel, and then obtains the optical brightness of each sub-pixel in the display panel based on the image obtained by the photo, and then obtains the optical brightness corresponding to the test display panel under the exposure time.

[0060] The exposure time is positively correlated with the optical brightness of the test display panel acquired by the optical camera within a certain range. The exposure time will affect the acquired optical brightness of the test display panel. For example, when the exposure time is short, the optical brightness of the area with smaller actual brightness in the test display panel acquired by the optical camera is darker, which will affect the judgment of the optical brightness of the darker area, so that there is a deviation between the optical brightness of the darker area and the actual brightness. In an optional embodiment, two different exposure times, such as an exposure time of 10S and an exposure time of 20S, can be used to expose the test display panel respectively, and the optical brightness of the test display panel corresponding to each exposure time can be obtained.

[0061] S130: Compensating the display panel to be compensated according to the optical brightness of the test display panel obtained each time under the display parameters of each binding point and the current display parameters of the display panel to be compensated.

[0062] For any binding point display parameter, in an optional implementation, the average value of the optical brightness of the test display panel corresponding to each exposure time under the binding point display parameter can be used as the corresponding optical brightness under the binding point display parameter, and then the compensation data corresponding to the binding point display parameter can be determined according to the optical brightness under the binding point display parameter.

[0063] After determining the compensation data corresponding to the display parameters of at least two binding points, the compensation data corresponding to the current display parameters of the display panel to be compensated can be determined by table lookup or difference, and then the display panel to be compensated is compensated according to the compensation data of the display panel to be compensated. The current display parameters of the display panel to be compensated can be the display brightness level and grayscale value corresponding to the display panel to be compensated in the current frame.

[0064] The embodiment of the present invention sets multiple exposure times to obtain optical brightness corresponding to the multiple exposure times, and performs data fitting on the optical brightness corresponding to the multiple exposure times, so that relatively real brightness data can be collected for an overly bright or overly dark screen that exceeds the dynamic range of the optical camera, and the compensation data corresponding to the binding point display parameters are determined according to the fitted optical brightness. The accuracy of the compensation data corresponding to the binding point display parameters is improved through data fitting, and then when the display panel to be compensated is compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the binding point display parameters, the accuracy of the compensation is improved.

[0065] Figure 2 A flowchart of another display panel brightness compensation method provided by an embodiment of the present invention, referring to Figure 2 , the method comprising:

[0066] S111: Light up the test display panels respectively with at least two binding point display parameters.

[0067] S121: for a test display panel lit under any binding point display parameter, the test display panel is exposed using at least two different exposure times respectively, and after each exposure, the optical brightness of the test display panel is acquired by an optical camera.

[0068] S131: for any binding point display parameter, generating compensation data corresponding to the binding point display parameter according to the optical brightness of the test display panel obtained each time under the binding point display parameter and the actual brightness of the test display panel under the binding point display parameter.

[0069] The compensation data may be a compensation amount of a data voltage or a compensation amount of a grayscale value, and there is no specific limitation on this. The compensation data may be a positive value or a negative value. In an optional embodiment, for any binding point display parameter, the average value of the optical brightness of the test display panel corresponding to each exposure time obtained under the binding point display parameter is used as the comprehensive brightness, and the corresponding compensation data is determined according to the difference between the comprehensive brightness and the actual brightness. Among them, the actual brightness of the test display panel can be obtained by a high-precision brightness acquisition device. In an optional embodiment, at any binding point display parameter, one sub-pixel corresponds to one compensation data. Specifically, for any sub-pixel in the test display panel, the average value of the optical brightness of the sub-pixel corresponding to each exposure time obtained under the binding point display parameter is used as the comprehensive brightness of the sub-pixel, and the compensation data corresponding to the sub-pixel is determined according to the difference between the comprehensive brightness and the actual brightness of the sub-pixel.

[0070] S141: Compensating the display panel to be compensated according to the current display parameters of the display panel to be compensated and compensation data corresponding to the display parameters of each binding point.

[0071] When there is a reference display parameter in the display parameters of each binding point, the compensation data corresponding to the reference display parameter is used as the compensation data of the display panel to be compensated; the reference display parameter is the same as the current display parameter of the display panel to be compensated; when there is no reference display parameter in the display parameters of all binding points, the compensation data of the display panel to be compensated is determined by interpolation calculation.

[0072] Exemplarily, in this implementation, two binding point display parameters are set, namely, the first binding point display parameter: 32 grayscales under 5nit, and the second binding point display parameter: 64 grayscales under 5nit. When the current display parameter of the display panel to be compensated is 32 grayscales under 5nit, the first binding point display parameter is the reference display parameter, and the compensation data corresponding to the first binding point display parameter is used as the compensation data of the display panel to be compensated under the current display parameter. When the current display parameter of the display panel to be compensated is 40 grayscales under 5nit, the compensation data corresponding to the current display parameter of the display panel to be compensated can be determined by linear interpolation based on the compensation data corresponding to the first binding point display parameter and the compensation data corresponding to the second binding point display parameter. The display panel to be compensated is compensated based on the compensation data of the display panel to be compensated. Specifically, a compensated data voltage is generated based on the compensation data of the display panel to be compensated, and the display panel to be compensated is driven by the compensated data voltage to display, so as to realize brightness compensation of the display panel to be compensated. Among them, when compensating the display panel to be compensated, the compensation data of the sub-pixel under the current display parameters can be determined according to the compensation data corresponding to the binding point display parameters of the sub-pixel at each position determined as described above, and then for any sub-pixel in the display panel to be compensated, the sub-pixel can be compensated according to the compensation data of the sub-pixel under the current display parameters.

[0073] In other implementations, for any binding point display parameter, all pixels in the entire test display panel may correspond to the same compensation data, and then the compensation data corresponding to each sub-pixel in the display panel to be compensated under the same display parameter is the same.

[0074] Figure 3 A flowchart of another brightness compensation method for a display panel provided by an embodiment of the present invention, Figure 3 The method shown is a further refinement of step S131. Figure 3 , optionally, the method includes:

[0075] S112: Light up the test display panels respectively with at least two binding point display parameters.

[0076] S122: for a test display panel lit under any binding point display parameter, respectively expose the test display panel using at least two different exposure times, and obtain the optical brightness of the test display panel through an optical camera after each exposure.

[0077] Optionally, when the test display panel is exposed using at least two different exposure times, the latter exposure time is greater than the previous exposure time. Exemplarily, when obtaining compensation data corresponding to the display parameters of each binding point, three different exposure times are set, and then the optical brightness of the test display panel corresponding to the three exposure times is obtained. In an optional embodiment, the first exposure time is set to 10S, the second exposure time is set to 20S, and the third exposure time is set to 30S, and then the optical brightness of the test display panel corresponding to the exposure time of 10S, the optical brightness of the test display panel corresponding to the exposure time of 20S, and the optical brightness of the test display panel corresponding to the exposure time of 30S are obtained respectively.

[0078] S132: for any binding point display parameter, generate a comprehensive brightness of the test display panel according to the optical brightness of the test display panel obtained each time.

[0079] In an optional implementation, the comprehensive brightness formula of the test display panel satisfies:

[0080] For any binding point display parameter: n is the total number of times the optical brightness of the test display panel is obtained, that is, the total number of exposure times set, C i is the weight coefficient corresponding to the optical brightness of the test display panel obtained for the i-th time, E i is the optical brightness of the test display panel obtained for the i-th time, i is an integer greater than or equal to 1 and less than or equal to n. According to the difference between the actual brightness of the test display panel under the binding point display parameters and the optical brightness of the test display panel obtained for each time, the weight coefficient corresponding to the optical brightness of the test display panel obtained for each time is determined. After the weight coefficient is determined, the comprehensive brightness of the test display panel is obtained according to the above formula. Among them, Ei can be a matrix including the optical brightness of each sub-pixel in the test display panel.

[0081] S142: For any binding point display parameter, generate compensation data corresponding to the binding point display parameter according to the comprehensive brightness of the test display panel and the actual brightness under the binding point display parameter.

[0082] When obtaining compensation data corresponding to any binding point display parameter, the compensation data corresponding to the binding point display parameter is determined according to the difference between the comprehensive brightness obtained in step S132 and the actual brightness.

[0083] S152: Compensating the display panel to be compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point.

[0084] After obtaining compensation data corresponding to multiple binding point display parameters, the multiple binding point display parameters and the compensation data corresponding to the binding point display parameters can be used to form a compensation table, and then after obtaining the current display parameters of the display panel to be compensated, the compensation data corresponding to the current display parameters of the display panel to be compensated can be obtained by table lookup or interpolation. For any sub-pixel, a compensated data voltage is generated according to the grayscale value currently corresponding to the sub-pixel and the compensation data, and the compensated data voltage is used to drive the corresponding sub-pixel for display.

[0085] In this embodiment, for any binding point display parameter, the optical brightness obtained after multiple exposures is fitted to obtain a comprehensive brightness formula for the test display panel, and then the compensation data corresponding to the test display panel under the binding point display parameter is determined according to the formula. By setting multiple exposure times and fitting the optical brightness obtained by multiple exposures, relatively real brightness data can be collected for over-bright or over-dark modules that exceed the dynamic range of the optical camera, thereby improving the accuracy of subsequent compensation of the display panel to be compensated.

[0086] Figure 4 FIG. 1 is a flowchart of another method for compensating brightness of a display panel provided in an embodiment of the present invention. Based on the above embodiment, this embodiment further refines step S132. Figure 4 , optionally, the method includes:

[0087] S113: Light up the test display panels respectively with at least two binding point display parameters.

[0088] S123: for the test display panel lit under any binding point display parameter, respectively expose the test display panel using at least two different exposure times, and obtain the optical brightness of the test display panel through an optical camera after each exposure.

[0089] Optionally, when obtaining compensation data corresponding to any binding point display parameter, the first exposure time is between 10S-20S. Preferably, the first exposure time is 15S, which is the conventional exposure time. The i-th exposure time is 0.8*i to 1.2*i times the first exposure time, where i is an integer greater than or equal to 2. Preferably, the i-th exposure time is i times the first exposure time. In a preferred embodiment, the first exposure time is set to 15S, the second exposure time is set to 30S, and the third exposure time is set to 45S.

[0090] Optionally, each time the test display panel is exposed, the optical camera is controlled to turn on the digital gain and the analog gain simultaneously.

[0091] The analog gain and digital gain of the camera are both ways to enhance the brightness of the image in the camera. Analog gain refers to the process of increasing the brightness of the image by amplifying the amplitude of the signal through an electronic amplifier during the transmission of the image signal. Analog gain is completed within the scope of the analog signal. Excessive gain will introduce noise, thereby affecting the quality of the image. Digital gain refers to adjusting the reference level of the AD converter to a smaller value during the image signal acquisition process, thereby increasing the amplitude of the image signal. Digital gain is completed within the scope of the digital signal, and the impact of noise can be reduced by post-image processing. Both analog gain and digital gain can be used to enhance the brightness of the image, but their implementation methods and effects are different. When using the camera, it is necessary to select a suitable gain method according to the specific shooting requirements and scenes to obtain better image quality. In this embodiment, the use of multiple exposures will increase the exposure time, so it is necessary to control the optical camera to turn on the digital gain and analog gain at the same time to eliminate and reduce the exposure time.

[0092] S133: for any binding point display parameter, determine the bright area and the dark area of ​​the test display panel according to the optical brightness of the test display panel obtained after the display panel is exposed using the first exposure time.

[0093] When obtaining the compensation data corresponding to any binding point display parameter, after obtaining the optical brightness of the test display panel corresponding to the first exposure time, determine the bright area and dark area of ​​the test display panel according to the optical brightness of the test display panel and the size of the preset brightness. The display panel includes multiple sub-pixels. When obtaining the brightness of the sub-pixels through an optical camera, it may not be possible to accurately obtain the brightness corresponding to each sub-pixel. The adjacent h sub-pixels can be regarded as a sub-pixel unit. The brightness of each sub-pixel unit is obtained through the image taken by the optical camera. The brightness of the sub-pixels belonging to the same sub-pixel unit is the same, which is the brightness of the sub-pixel unit. When the optical brightness of the sub-pixel unit is greater than the preset brightness, the sub-pixel unit is divided into a bright area. When the optical brightness of the sub-pixel unit is less than the preset brightness, the sub-pixel unit is divided into a dark area. Among them, the preset brightness can be set according to demand. The positions of the bright area and the dark area determined by different binding point display parameters may be different.

[0094] S143: For any binding point display parameter, determine the weight coefficient corresponding to the optical brightness of the bright area of ​​the test display panel obtained each time, and the weight coefficient corresponding to the optical brightness of the dark area of ​​the test display panel obtained each time, according to the optical brightness of the bright area of ​​the test display panel, the optical brightness of the dark area of ​​the test display panel obtained each time, and the actual brightness of the test display panel under the binding point display parameter.

[0095] For any binding point display parameter, by continuously adjusting the weight coefficient corresponding to the optical brightness of the bright area, the comprehensive brightness of the bright area after multiple data fitting is closest to the actual brightness. By continuously adjusting the weight coefficient corresponding to the optical brightness of the dark area, the comprehensive brightness of the dark area after multiple data fitting is closest to the actual brightness.

[0096] S153: For any binding point display parameter, determine the comprehensive brightness of the test display panel according to the brightness function of the bright area and the brightness function of the dark area.

[0097] Among them, the brightness function W of the bright area satisfies:

[0098] n is the total number of times the optical brightness of the test display panel is obtained, that is, the number of different exposure times set, A i is the weight coefficient corresponding to the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, W i is the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, i is an integer greater than or equal to 1 and less than or equal to n,

[0099] The brightness function D of the dark area satisfies:

[0100] B i is the weight coefficient corresponding to the optical brightness of the dark area of ​​the test display panel obtained for the i-th time, D i is the optical brightness of the dark area of ​​the test display panel obtained for the i-th time, i is an integer greater than or equal to 1 and less than or equal to n.

[0101] n is an integer greater than or equal to 2. In an optional embodiment, n is greater than or equal to 2 and less than or equal to 5. For any binding point display parameter, the positions of the dark area and the bright area are determined according to the optical brightness of the test display panel obtained at the first exposure time, and the positions of the dark area and the bright area are the same as the first time when the optical brightness of the test display panel is obtained at each exposure time. i is the optical brightness matrix of the bright area of ​​the test display panel obtained for the i-th time, and the matrix includes the optical brightness corresponding to each sub-pixel unit in the bright area at the i-th exposure time. i is the optical brightness matrix of the dark area of ​​the test display panel obtained for the i-th time, and the matrix includes the optical brightness corresponding to each sub-pixel unit in the dark area at the i-th exposure time.

[0102] Optionally, the test display panel includes a plurality of sub-pixels, and the comprehensive brightness of the test display panel includes the comprehensive brightness of each sub-pixel. The sub-pixels in this embodiment can be regarded as the sub-pixel units described above. The comprehensive brightness of the preset sub-pixel is set to a fixed brightness value; wherein the preset sub-pixel is a pixel whose comprehensive brightness is less than or equal to the brightness threshold. After the comprehensive brightness of each sub-pixel is obtained through step S153, the brightness of the sub-pixel whose brightness is still too low is filled with a fixed brightness value to eliminate the problem of too high compensation value of the Demura algorithm caused by low brightness, and reduce the problem of inability to compensate due to too high compensation value of the algorithm. The fixed brightness value can be a fixed value obtained based on experience, or, in an optional embodiment, the comprehensive brightness of any sub-pixel adjacent to the preset sub-pixel is used as a fixed brightness value. In other optional embodiments, the average value of the comprehensive brightness of multiple sub-pixels adjacent to the preset sub-pixel can also be used as a fixed brightness value, such as the average value of the comprehensive brightness of multiple adjacent sub-pixels surrounding the preset sub-pixel is used as a fixed brightness value.

[0103] S163: For any binding point display parameter, generate compensation data corresponding to the binding point display parameter according to the comprehensive brightness of the test display panel and the actual brightness under the binding point display parameter.

[0104] After the weight coefficients corresponding to each pixel unit in the bright area are determined, the comprehensive brightness of each sub-pixel unit after fitting can be obtained. For any sub-pixel unit in the bright area, the compensation data of the sub-pixel unit is generated according to the comprehensive brightness and the actual brightness. Similarly, after the weight coefficients corresponding to each pixel unit in the dark area are determined, the comprehensive brightness of each sub-pixel unit after fitting can be obtained. For any sub-pixel unit in the dark area, the compensation data of the sub-pixel unit is generated according to the comprehensive brightness and the actual brightness, and then the compensation data corresponding to each pixel unit under any binding point display parameter is obtained.

[0105] S173: Compensating the display panel to be compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point.

[0106] For any sub-pixel unit, when there is a reference display parameter in the binding point display parameter, the compensation data corresponding to the sub-pixel unit under the reference display parameter is used as the compensation data of the sub-pixel unit under the current display parameter. When there is no reference display parameter in all binding point display parameters, the compensation data of the sub-pixel unit under the current display parameter is determined by interpolation calculation.

[0107] In this embodiment, data fitting is performed for bright areas and dark areas respectively, which can further improve the accuracy of the obtained comprehensive brightness of each sub-pixel, thereby improving the accuracy of the compensation data corresponding to the binding point display parameters, thereby improving the accuracy of the subsequent determination of the compensation data of the display panel to be compensated based on the compensation data of the binding point display parameters.

[0108] This embodiment adopts steps S113-S153 to determine the comprehensive brightness of the test display panel under any binding point display parameter, and performs a simulation test to obtain the optical brightness diagram of the test display panel before and after optimization. Figure 5 is the optical brightness diagram of the test display panel obtained by conventional exposure time under the tied point display parameters, Figure 6 is the optical brightness diagram of the test display panel obtained by fitting the optical brightness through multiple exposures under the tied point display parameters. Figure 6 is the optical brightness diagram obtained by fitting the optical brightness obtained at three different exposure times. Figure 5 and Figure 6 It can be seen that the optical brightness of the test display panel obtained after optimization by using the multiple exposure fitting method has a lower brightness area than the Figure 5 The brightness of the area with lower brightness is reduced, while the brightness value obtained through the image is inaccurate. Therefore, the method in this embodiment can make the comprehensive brightness of the test display panel obtained more accurate, and make the corresponding compensation data under the corresponding binding point display parameters more accurate, and then make the compensation data corresponding to the current display parameters determined according to the corresponding compensation data under the binding point display parameters more accurate.

[0109] This embodiment uses steps S113-S173 to determine the compensation data corresponding to the current display parameters, and obtains the compensation distribution diagram of sub-pixels under different colors. Specifically, Figure 7 is the compensation distribution diagram obtained by a regular exposure time under the current display parameters, Figure 8 is the compensation distribution diagram obtained by fitting the optical brightness through multiple exposures under the current display parameters. Figure 7 and Figure 8 The graphs include three graphs, wherein Histrange-Offset_B represents the compensation distribution graph of the blue sub-pixel, Histrange-Offset_G represents the compensation distribution graph of the green sub-pixel, and Histrange-Offset_R represents the compensation distribution graph of the red sub-pixel. Figure 7 Hezhong Figure 8 The horizontal coordinate offset_value in is the grayscale compensation value, and the vertical coordinate frequency is the number of sub-pixels. Figure 7 still Figure 8For any data point (x, y) in any of the three images, it means that there are y sub-pixels of the corresponding color whose compensated grayscale value to be compensated is x.

[0110] pass Figure 7 and Figure 8 It can be seen that according to the compensation data corresponding to the current display parameters and the optical brightness of the test display panel obtained by a regular exposure time, in the compensation data of the current display parameters, the larger the compensation grayscale value, the larger the number of pixels corresponding to it, especially the red sub-pixels. However, according to the compensation data obtained by fitting the current display parameters and the optical brightness of the test display panel obtained by multiple exposure times, in the compensation data of the current display parameters, the number of pixels corresponding to the larger compensation grayscale value is very small. In summary, it can be seen that the compensation distribution diagram generated by the method of this embodiment is more in line with the Zhengtai distribution, and the excessive compensation data disappears significantly after optimization, and the effectiveness of the collected dark area data is significantly improved.

[0111] In this embodiment, a relative brightness error table and a relative error comparison diagram corresponding to different exposure times at multiple points are obtained through experiments. For details, see Table 1 and Fig. 9 .

[0112] Table 1 Relative error of comprehensive brightness corresponding to different exposure times

[0113]

[0114]

[0115] The points in Table 1 indicate different positions of the test display panel. Fig. 9 This is a relative error comparison diagram of the comprehensive optical brightness of the test display panel obtained by single exposure and double exposure, where the comprehensive brightness of the test display panel corresponding to the single exposure is the optical brightness of the test display panel obtained by the optical camera, and the relative error is equal to the percentage of the ratio of the absolute value of the difference between the comprehensive optical brightness and the actual brightness to the actual brightness. Fig. 9 The horizontal axis is the point position, the vertical axis is the relative error, the blue curve is the relative error curve between the optical brightness of the display panel after one exposure and the actual brightness, and the red curve is the relative error curve between the comprehensive optical brightness of the display panel after two exposures and the actual brightness, where the actual brightness can be obtained by a CS20000 brightness meter. Fig. 9 It can be seen that the relative error of the comprehensive optical brightness after multiple exposure fitting and the actual brightness obtained by the cs2000 brightness meter is reduced from 45.12% to 16.44%, and the accuracy of the dark area is significantly improved. Fig. 9The two curves correspond to relative error curves obtained by lighting up the test display panel under the same binding point display parameters.

[0116] In addition, this embodiment also selected 10 display panels, and conducted experiments using one conventional exposure and multiple exposures in this embodiment, respectively, to obtain a brightness and color uniformity comparison table, see Table 2.

[0117] Table 2 Comparison of brightness and color uniformity of display panels after compensation of optical brightness obtained at different exposure times

[0118] serial number DMR_off One-shot uniformity Multiple exposure uniformity 1 80.49 39.39 26.52 2 98 50.58 39.19 3 128.62 80.7 80.75 4 39.48 13.43 14.92 5 68.93 28.9 28.1 6 59.28 10.23 11.04 7 103.38 61.1 55.73 8 98.63 60.89 55.19

[0119] Different numbers in Table 1 represent different screens, and each screen is lit at 32 grayscales under 2nit. After lighting, the right side of screen 1 is dark and green, the upper side of screen 2 is bright and the lower side is dark, the left side of screen 3 is red and dark, screen 4 is normal, the right side of screen 5 is medium dark, the lower side of screen 6 is slightly dark, the left side of screen 7 is dark and red, and the right side of screen 8 is dark and green. In Table 2, DMR_off is the brightness and color uniformity of the screen before data compensation, the single exposure uniformity is the brightness and color uniformity of the screen after the compensation data of the binding point display parameters determined by one exposure time is used, and then the compensation data corresponding to the 32 grayscales and the binding point display parameters under 2nit are used to compensate the screen, and the multi-exposure uniformity is the brightness and color uniformity of the screen after the compensation data of the binding point display parameters determined by multiple exposure times, such as three exposure times, is used, and then the compensation data corresponding to the 32 grayscales and the binding point display parameters under 2nit are used to compensate the screen. Among them, the smaller the value of brightness uniformity, the better the brightness uniformity of the screen. By comparing the brightness uniformity values ​​of single and multiple exposure times, it can be seen that the brightness uniformity of screens 1 and 2 is improved under multiple exposure times compared with single exposure time, screen 3 is not improved, screen 4 is not significantly improved, screen 5 and screen 6 are not improved, and screen 7 and screen 8 are slightly improved.

[0120] Fig.10 A schematic diagram of the structure of a system for performing brightness compensation on a display panel provided by an embodiment of the present invention. Fig.11 This is a principle block diagram of a driver chip, a memory and a display panel provided by an embodiment of the present invention. In this embodiment, the test display panel and the display panel to be compensated are taken as the same display panel. The compensation data corresponding to the display parameters of at least two binding points can be obtained before the display panel leaves the factory and stored in the memory. Fig.10 and Fig.11, the system includes an optical camera (CCD) 1, a conversion module 2, a lighting fixture 3, a display panel 4, a memory 5 and a driver chip 6. The system also includes a horizontal stage, a sliding bracket with high-precision electric height control, a sensor with a positioning function, and a computer device. The lighting fixture 3 is used to light up the display panel. After lighting up, the computer transmits a specific picture. The optical camera 1 obtains the original brightness data by sampling the data of the specific picture. The horizontal stage is used to flatten the display panel to keep the shooting height horizontal. The sensor with a positioning function is used to locate the position of the screen of the display panel. Among them, under the binding point display parameters, the optical camera 1 obtains the brightness of the display panel 4 at different exposure times and transmits it to the conversion module 2 to generate compensation data corresponding to the binding point display parameters in the conversion module 2. The lighting fixture 3 burns the compensation data to the memory 5 through the driver chip 6, which can be a Flash memory, so that the compensation data can be loaded from the Flash memory to the driver chip 6 during subsequent compensation. For details, please refer to Fig.11 .

[0121] An embodiment of the present invention further provides a display panel controlled by the brightness compensation method of the display panel in any of the above embodiments.

[0122] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0123] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A brightness compensation method for a display panel, characterized in that: include: Lighting up the test display panel respectively with at least two binding point display parameters; For a test display panel lit under any of the binding point display parameters, the test display panel is exposed using at least two different exposure times, and the optical brightness of the test display panel is acquired by an optical camera after each exposure; The display panel to be compensated is compensated according to the optical brightness of the test display panel acquired each time under each binding point display parameter and the current display parameters of the display panel to be compensated.

2. The brightness compensation method of a display panel according to claim 1, characterized in that: The display parameters include display brightness level and grayscale value, and the compensation of the display panel to be compensated according to the optical brightness of the test display panel obtained each time under each binding point display parameter and the current display parameters of the display panel to be compensated includes: For any binding point display parameter, generating compensation data corresponding to the binding point display parameter according to the optical brightness of the test display panel acquired each time under the binding point display parameter and the actual brightness of the test display panel under the binding point display parameter; The display panel to be compensated is compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point.

3. The brightness compensation method of a display panel according to claim 2, characterized in that: The generating the compensation data corresponding to the binding point display parameter according to the optical brightness of the test display panel acquired each time under the binding point display parameter and the actual brightness of the test display panel under the binding point display parameter comprises: Generate a comprehensive brightness of the test display panel according to the optical brightness of the test display panel obtained each time; Compensation data corresponding to the binding point display parameters are generated according to the comprehensive brightness of the test display panel and the actual brightness under the binding point display parameters.

4. The brightness compensation method of a display panel according to claim 3, characterized in that: Generating the comprehensive brightness of the test display panel according to the optical brightness of the test display panel obtained each time includes: Determining a bright area and a dark area of ​​the test display panel according to an optical brightness of the test display panel obtained after exposing the display panel using a first exposure time; Determine a weight coefficient corresponding to the optical brightness of the bright area and the optical brightness of the dark area of ​​the test display panel obtained each time, according to the optical brightness of the bright area and the optical brightness of the dark area of ​​the test display panel obtained each time and the actual brightness of the test display panel under the binding point display parameters; Determining the integrated brightness of the test display panel according to the brightness function of the bright area and the brightness function of the dark area; Wherein, the brightness function W of the bright area satisfies: n is the total number of times the optical brightness of the test display panel is obtained, A i is the weight coefficient corresponding to the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, W i is the optical brightness of the bright area of ​​the test display panel obtained for the i-th time, i is an integer greater than or equal to 1 and less than or equal to n, The brightness function D of the dark area satisfies: B i is the weight coefficient corresponding to the optical brightness of the dark area of ​​the test display panel obtained for the i-th time, D i is the optical brightness of the dark area of ​​the test display panel obtained for the i-th time, 5. The brightness compensation method of a display panel according to claim 3, characterized in that: The test display panel includes a plurality of sub-pixels, the comprehensive brightness of the test display panel includes the comprehensive brightness of each sub-pixel, and after generating the comprehensive brightness of the test display panel according to the optical brightness of the test display panel acquired each time, the method further includes: The integrated brightness of a preset sub-pixel is set to a fixed brightness value; wherein the preset sub-pixel is a pixel whose integrated brightness is less than or equal to a brightness threshold.

6. The brightness compensation method of a display panel according to claim 5, characterized in that: The integrated brightness of any sub-pixel adjacent to the preset sub-pixel is used as the fixed brightness value, or the average value of the integrated brightness of multiple sub-pixels adjacent to the preset sub-pixel is used as the fixed brightness value.

7. The brightness compensation method of a display panel according to claim 2, characterized in that: The compensating the display panel to be compensated according to the current display parameters of the display panel to be compensated and the compensation data corresponding to the display parameters of each binding point comprises: When there is a reference display parameter in each of the binding point display parameters, the compensation data corresponding to the reference display parameter is used as the compensation data of the display panel to be compensated; the reference display parameter is the same as the current display parameter of the display panel to be compensated; when there is no reference display parameter in all the binding point display parameters, the compensation data of the display panel to be compensated is determined by interpolation calculation; The display panel to be compensated is compensated according to the compensation data of the display panel to be compensated.

8. The brightness compensation method of a display panel according to claim 1, characterized in that: When the test display panel is exposed using at least two different exposure times respectively, the latter exposure time is greater than the previous exposure time; Preferably, the first exposure time is between 10S and 20S; Preferably, the i-th exposure time is 0.8*i times to 1.2*i times the first exposure time, where i is an integer greater than or equal to 2.

9. The brightness compensation method of a display panel according to claim 1, characterized in that: Also includes: Each time the test display panel is exposed, the optical camera is controlled to simultaneously turn on the digital gain and the analog gain.

10. A display panel, characterized in that: Controlled by the brightness compensation method of the display panel according to any one of claims 1 to 9.

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