A display panel brightness data acquisition method and a display panel compensation method

Abstract

This application provides a method for acquiring brightness data of a display panel, relating to the field of display technology. The method includes: acquiring brightness data of the display panel to be compensated in a first color channel; calculating the brightness data of the display panel in a second color channel according to a first mapping relationship; the first mapping relationship being a pre-established brightness value mapping relationship between the first color channel and the second color channel; and calculating the brightness data of the display panel in a third color channel according to a second mapping relationship; the second mapping relationship being a pre-established brightness value mapping relationship between the first color channel and the third color channel. This method can improve the efficiency of acquiring brightness data of the display panel and increase production efficiency.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for acquiring brightness data of a display panel and a method for compensating for a display panel. Background Technology

[0002] With the development of display technology, organic light-emitting diode (OLED) devices are widely used in various display products such as mobile phones, tablets, automotive screens, and smartwatches.

[0003] In practical applications, uneven brightness exists across different display areas of a display panel, severely impacting display quality. To address this issue, Mura compensation (brightness uniformity compensation) is typically performed on the display panel before it leaves the factory. However, obtaining brightness data from the display panel is currently inefficient, significantly affecting production efficiency. Summary of the Invention

[0004] This application provides a method for acquiring display panel brightness data and a method for compensating display panel brightness data, aiming to improve the efficiency of acquiring and generating display panel brightness data.

[0005] In a first aspect, embodiments of this application provide a method for acquiring brightness data of a display panel, the method comprising:

[0006] Obtain the brightness data of the display panel to be compensated in the first color channel; The brightness data of the display panel in the second color channel is calculated according to the first mapping relationship; the first mapping relationship is a pre-established mapping relationship between the brightness values ​​of the first color channel and the second color channel; The brightness data of the display panel in the third color channel is calculated based on the second mapping relationship; the second mapping relationship is a pre-established brightness value mapping relationship between the first color channel and the third color channel.

[0007] In one possible implementation, both the first mapping relationship and the second mapping relationship include a first mapping parameter, a second mapping parameter, and a third mapping parameter. The first mapping parameter of the first mapping relationship has a different value than the first mapping parameter of the second mapping relationship. The second mapping parameter of the first mapping relationship has a different value than the second mapping parameter of the second mapping relationship. The third mapping parameter of the first mapping relationship has a different value than the third mapping parameter of the second mapping relationship.

[0008] In one possible implementation, the display panel includes multiple sub-display areas, and at least one of the first mapping relationship and the second mapping relationship includes multiple sub-mapping relationships. The multiple sub-mapping relationships of the first mapping relationship and the second mapping relationship correspond one-to-one with the multiple sub-display areas. Each sub-mapping relationship includes a first sub-mapping parameter, a second sub-mapping parameter, and a third sub-mapping parameter. The step of calculating the brightness data of the display panel in the second color channel according to the first mapping relationship includes: The brightness data of each sub-display area of ​​the display panel in the second color channel is calculated based on the multiple sub-mapping relationships included in the first mapping relationship; The step of calculating the brightness data of the display panel in the third color channel according to the second mapping relationship includes: The brightness data of each sub-display area of ​​the display panel in the third color channel is calculated based on the multiple sub-mapping relationships included in the second mapping relationship.

[0009] In one possible implementation, the first mapping relationship includes: Lv_R(g) = α1 [Lv_G(g)]^γ1+β1; the second mapping relationship includes: Lv_B(g)=α2 [Lv_G(g)]^γ2+β2; Wherein, Lv_G(g) represents the brightness value of the first color channel at gray level g; Lv_R(g) represents the brightness value of the second color channel at gray level g; Lv_B(g) represents the brightness value of the third color channel at gray level g; the first mapping parameters include α1 and α2, representing brightness scaling factors; the second mapping parameters include γ1 and γ2, representing nonlinear exponents; and the third mapping parameters include β1 and β2, representing bias parameters.

[0010] In one possible implementation, the first mapping parameter, the second mapping parameter, and the third mapping parameter are obtained in the following way: The brightness of multiple sub-display areas of the sample display panel under multiple preset gray levels is obtained in the first color channel, the second color channel, and the third color channel. Based on the brightness of each sub-display area under multiple preset gray levels and the first, second, and third color channels, the first, second, and third sub-mapping parameters corresponding to each sub-display area are calculated to obtain the first, second, and third mapping parameters of the display panel.

[0011] In one possible implementation, the first mapping parameter, the second mapping parameter, and the third mapping parameter are obtained by acquiring the first mapping parameter, the second mapping parameter, and the third mapping parameter of the multiple sample display panels in a certain manner. Calculate the weighted average of multiple first mapping parameters as the final first mapping parameter, calculate the weighted average of multiple second mapping parameters as the final second mapping parameter, and calculate the weighted average of multiple third mapping parameters as the final third mapping parameter.

[0012] In one possible implementation, the second mapping parameter is obtained in the following way: The brightness of the sub-display area of ​​the sample display panel under the first gray level and the second gray level is measured in the first color channel, the second color channel and the third color channel. The second mapping parameter is calculated based on the following formula: γ1=γ R / γ G , γ2=γ B / γ G ; γ G =log[Lv_G(X) / Lv_G(Y)] / log(X); γ R =log[Lv_R(X) / Lv_R(Y)] / log(X); γ B =log[Lv_B(X) / Lv_B(Y)] / log(X); Where Lv_G(X) is the first grayscale brightness of the first color channel, and Lv_G(Y) is the second grayscale brightness of the first color channel; Lv_R(X) is the first grayscale brightness of the second color channel, and Lv_R(Y) is the second grayscale brightness of the second color channel; Lv_B(X) is the first grayscale brightness of the third color channel, and Lv_B(Y) is the second grayscale brightness of the third color channel, γ G Indicates the gamma value of the first color channel; γ R γ represents the gamma value of the second color channel. B γ represents the gamma value of the third color channel. 1、 γ2 is the second mapping parameter.

[0013] In one possible implementation, the first mapping parameter is obtained in the following way: Obtain the maximum brightness of the sub-display area of ​​the sample display panel under the first color channel, the second color channel, and the third color channel; The first mapping parameter is calculated based on the following formula: α1=Lv_R_max / (Lv_G_max)^γ1; α2=Lv_B_max / (Lv_G_max)^γ2; Where Lv_G_max represents the maximum brightness in the first color channel, Lv_R_max represents the maximum brightness in the second color channel, and Lv_B_max represents the maximum brightness in the third color channel, γ 1、 γ2 is the second mapping parameter.

[0014] In one possible implementation, the third mapping parameter is obtained in the following way: Obtain the color coordinates of the sub-display area of ​​the sample display panel at the maximum gray level, and calculate the deviation value Δu'v' between the measured value and the standard value of the color coordinates; The third mapping parameter is calculated based on the following formula: β1=k1 Δu'v'; β2=k2 Δu'v'; Where k1 and k2 are adjustment coefficients.

[0015] Secondly, embodiments of this application provide a display panel compensation method, which obtains brightness data according to the brightness data method described in the first aspect, generates brightness compensation data, and performs brightness compensation on the display panel.

[0016] This application provides a method for pre-establishing a first mapping relationship and a second mapping relationship. The brightness data of the second and third color channels are calculated by mapping the brightness data of the first color channel. Compared to existing technologies that require separate acquisition of brightness data for the red, green, and blue channels (three acquisitions per grayscale), this embodiment only requires acquisition of the first color channel once to calculate the brightness data of the second and third color channels. The brightness data acquisition time is reduced to one-third of the original time. This significantly improves production efficiency for large-scale production lines. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an exemplary flowchart illustrating a method for acquiring brightness data of a display panel provided in an embodiment of this application; Figure 2 This is an exemplary flowchart illustrating another method for acquiring display panel brightness data provided in this application embodiment; Figure 3 This is an exemplary schematic diagram of multiple sub-display areas of a display panel provided in an embodiment of this application; Figure 4 This is a schematic diagram of a multi-channel, multi-grayscale brightness of a display panel provided in an embodiment of this application. Detailed Implementation

[0019] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0021] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0022] In related technologies, due to limitations in equipment and processes, LTPS TFTs fabricated on large-area glass substrates often exhibit non-uniformity in electrical parameters such as threshold voltage and mobility at different locations. This non-uniformity translates into current and brightness differences in OLED display devices, which are perceived by the human eye—the Mura phenomenon. To eliminate the Mura phenomenon in display panels, high-precision cameras are typically used to capture the actual brightness distribution of the display panel at different grayscale levels, recording the brightness data of each Mura region on the display panel. The recorded brightness of the Mura region is compared with the standard uniform target brightness value, and the required offset value relative to the target brightness value for each pixel is calculated as a compensation value (De-mura data).

[0023] Currently, brightness data acquisition mainly relies on monochrome cameras to capture brightness images of the R / G / B channels of the display panel at different gray levels. In order to ensure the full gray level compensation effect, one or even multiple brightness levels and multiple high, medium and low gray level data are usually acquired. For example, 6x3=18 optical data are acquired for the three RGB channels at gray levels of 224, 192, 128, 64, 32 and 16. Therefore, the current brightness data acquisition process of display panels is time-consuming.

[0024] To address the aforementioned technical problems, embodiments of this application provide a method for acquiring display panel brightness data, such as... Figure 1 As shown, the method includes: S101. Obtain the brightness data of the display panel to be compensated in the first color channel.

[0025] In this embodiment, the first color channel can be any one of red (R), green (G), or blue (B). To obtain the best mapping accuracy, the color channel with the highest luminous efficiency, the most stable lifetime decay characteristics, or the greatest impact on display quality is usually selected as the first color channel. In a preferred example, since green subpixels typically have the highest luminous efficiency in conventional display panels, and the human eye is most sensitive to changes in green brightness, the green (G) channel can be used as the first color channel.

[0026] The brightness data under the first color channel includes: driving the display panel to display a monochrome image under multiple preset gray levels, that is, only lighting up the sub-pixels of the first color channel. For example, only lighting up the green sub-pixels on the display panel can be done to obtain the brightness data of the display panel under 32 gray level, 64 gray level, 128 gray level, 192 gray level and 255 gray level respectively.

[0027] Specifically, a monochrome camera can be used to capture the brightness distribution image of the entire display panel at each grayscale level. By processing the brightness distribution image, the brightness value of each pixel or each sub-display area at that grayscale level can be obtained. These brightness values ​​constitute the raw brightness dataset for the first color channel.

[0028] S102. Calculate the brightness data of the display panel in the second color channel according to the first mapping relationship.

[0029] The first mapping relationship is a pre-established mapping relationship of brightness values ​​between the first color channel and the second color channel.

[0030] S103. Calculate the brightness data of the display panel in the third color channel according to the second mapping relationship.

[0031] The second mapping relationship is a pre-established mapping relationship of brightness values ​​between the first color channel and the third color channel.

[0032] In one alternative implementation, the first and second mapping relationships can be a global mapping table. This mapping table records the correspondence between the brightness values ​​of the first color channel and the brightness values ​​of the second color channel. For example, when the brightness of the green channel is Lv_G, the brightness of the red channel is Lv_R = f_RG(Lv_G), where f_RG() is a function obtained by fitting experimental data.

[0033] In another, more preferred implementation, the first and second mapping relationships can be a non-linear parameterized model that can adapt to the non-linear brightness characteristics under different gray levels.

[0034] This application provides a method for pre-establishing a first mapping relationship and a second mapping relationship. The brightness data of the second and third color channels are calculated by mapping the brightness data of the first color channel. Compared to existing technologies that require separate acquisition of brightness data for the red, green, and blue channels (requiring three acquisitions per grayscale level), this embodiment only requires one acquisition of the green channel to calculate the brightness data of the red and blue channels. When 15 grayscale levels need to be acquired, the existing technology requires 15 acquisitions. In this embodiment, only 15 data collection attempts are required instead of the previous 3, reducing data acquisition time to one-third of the original. This significantly improves production efficiency for large-scale production lines.

[0035] Furthermore, since this solution does not require frequent switching of color channels for shooting, the response speed requirements of the image acquisition equipment are reduced, and only a monochrome camera is needed to photograph the display panel, thus reducing equipment costs.

[0036] In another embodiment of this application, both the first mapping relationship and the second mapping relationship in the above embodiments include a first mapping parameter, a second mapping parameter, and a third mapping parameter. The first mapping parameter of the first mapping relationship has a different value than the first mapping parameter of the second mapping relationship, the second mapping parameter of the first mapping relationship has a different value than the second mapping parameter of the second mapping relationship, and the third mapping parameter of the first mapping relationship has a different value than the third mapping parameter of the second mapping relationship.

[0037] Specifically, the first mapping relationship includes: Lv_R(g) = α1 [Lv_G(g)]^γ1+β1; the second mapping relationship includes: Lv_B(g)=α2 [Lv_G(g)]^γ2+β2; Wherein, Lv_G(g) represents the brightness value of the first color channel at gray level g; Lv_R(g) represents the brightness value of the second color channel at gray level g; and Lv_B(g) represents the brightness value of the third color channel at gray level g. In this embodiment of the application, the first mapping parameters include α1 and α2, which represent brightness scaling factors and are used to control the overall scaling ratio of brightness.

[0038] The second mapping parameters include γ1 and γ2, which represent nonlinear exponents and are used to control the nonlinear variation trend of brightness.

[0039] The third mapping parameters include β1 and β2, which represent bias parameters used to compensate for light leakage or minimum luminance of subpixels in dark conditions.

[0040] Understandably, this is because red, green, and blue subpixels possess different physical properties. For example, in the same OLED display panel, the quantum efficiency of the luminescent material in red subpixels is typically higher than that in blue subpixels, but their aging rate is faster; simultaneously, the gamma curves of red and blue subpixels also differ. Therefore, different mapping parameter values ​​must be used to accurately describe the mapping patterns of each channel; that is, the values ​​of the first mapping parameter α1 and α2 must be different, the values ​​of the second mapping parameter γ1 and γ2 must be different, and the values ​​of the third mapping parameter β1 and β2 must be different.

[0041] The embodiments of this application can accurately fit the nonlinear characteristics of different color channels. Since the luminous efficiency and gamma characteristics of red and blue sub-pixels have inherent differences, different first and second mapping parameters can be used to adapt their respective response curves, avoiding large errors on a single channel when using the same mapping parameter. Different color channels may have different levels of light leakage in the dark; by using an independent third mapping parameter, dark-state light leakage compensation can be performed separately for each channel, improving the accuracy in low grayscale areas.

[0042] To improve the accuracy of brightness mapping, the display panel can also be partitioned. In another embodiment of this application, the display panel includes multiple sub-display areas, and at least one of the first mapping relationship and the second mapping relationship includes multiple sub-mapping relationships. Each sub-mapping relationship corresponds one-to-one with a multiple sub-display area, and each sub-mapping relationship includes a first sub-mapping parameter, a second sub-mapping parameter, and a third sub-mapping parameter. Figure 2 As shown, Figure 2 This is a flowchart illustrating another method for acquiring display panel brightness data provided in an embodiment of this application.

[0043] The above-mentioned S102, calculating the brightness data of the display panel in the second color channel according to the first mapping relationship, can be specifically implemented as follows: S1021. Calculate the brightness data of each sub-display area of ​​the display panel in the second color channel according to the multiple sub-mapping relationships included in the first mapping relationship; The above-mentioned S103, calculating the brightness data of the display panel in the third color channel according to the second mapping relationship, can be specifically implemented as follows: S1031. Calculate the brightness data of each sub-display area of ​​the display panel in the third color channel according to the multiple sub-mapping relationships included in the second mapping relationship.

[0044] In this embodiment, the display area of ​​the display panel can be divided into multiple sub-display areas. The division method can be a uniform rectangular grid. For example, the display area of ​​the display panel can be uniformly divided into 3... Three sub-display areas. The panel can also be divided non-uniformly based on its manufacturing process, for example, by dividing the edge areas into finer sub-display areas.

[0045] like Figure 3 As shown, Figure 3 The display panel shown is divided into 9 sub-display areas. The first mapping relationship and the second mapping relationship each include 9 sub-mapping relationships, or only the first mapping relationship includes 9 sub-mapping relationships, or only the second mapping relationship includes 9 sub-mapping relationships. When both the first mapping relationship and the second mapping relationship include 9 sub-mapping relationships, each sub-display area A11-A33 of the display panel corresponds to an independent sub-mapping relationship of the first mapping relationship and a sub-mapping relationship of the second mapping relationship.

[0046] Each sub-display area i (i=1,2,...,N) corresponds to an independent set of sub-mapping relationships. For the first mapping relationship (e.g., green to red), there are N sub-mapping relationships, each containing its own sub-mapping parameters. Similarly, for the second mapping relationship (green to blue), there are also N independent sub-mapping relationships.

[0047] When acquiring the brightness data of the first color channel of the display panel to be compensated, it is necessary to acquire it according to the sub-display areas. That is, for each sub-display area i, the brightness data of that area in the first color channel is measured or calculated.

[0048] Then, based on the multiple sub-mapping relationships included in the first mapping relationship, the brightness data of each sub-display area in the second color channel is calculated. Specifically, for sub-display area i, the brightness data in the first color channel is substituted into the sub-mapping relationship corresponding to this area (from green to red) to obtain the brightness data in the second color channel. By performing the calculation sequentially for all sub-display areas, the red brightness distribution of the entire panel can be obtained.

[0049] Similarly, based on the multiple sub-mapping relationships included in the second mapping relationship, the brightness data of each sub-display area in the third color channel is calculated. For sub-display area i, the brightness data in the first color channel is substituted into the calculation, and the corresponding sub-mapping relationship (from green to blue) is used to calculate the brightness data in the third color channel.

[0050] The solution provided in this application can significantly improve the brightness estimation accuracy of in-plane non-uniform panels. In actual production, due to factors such as deformation of the vapor deposition mask, uneven thickness, and TFT threshold voltage drift, the relationship between color channels in different areas of the display panel often differs. For example, the left side of the panel may have brighter red while the right side has brighter green. Global mapping cannot simultaneously meet the accuracy requirements of both sides, while partition mapping can optimize each area individually. It supports local compensation and repair. In subsequent Demura compensation, if only the brightness of a few sub-display areas is abnormal, only the mapping parameters or compensation coefficients of that sub-display area can be updated, without recalculating the data of the entire panel, greatly reducing the amount of data processing. It adapts to process fluctuations of different batches of panels. For panels of the same model but different production batches, process fluctuations may cause changes in the distribution pattern of in-plane non-uniformity. Through partition mapping, the partition mapping parameters calibrated by the sample panels of the corresponding batch can be used directly without modifying the algorithm framework.

[0051] Corresponding to the above implementation of partition mapping, the first mapping parameter, the second mapping parameter, and the third mapping parameter are obtained in the following manner: Step 1: Obtain the brightness of multiple sub-display areas of the sample display panel under multiple preset gray levels in the first color channel, second color channel, and third color channel; Step 2: Based on the brightness of each sub-display area under multiple preset gray levels in the first color channel, second color channel, and third color channel, calculate the first sub-mapping parameter, second sub-mapping parameter, and third sub-mapping parameter corresponding to each sub-display area to obtain the first mapping parameter, second mapping parameter, and third mapping parameter of the display panel.

[0052] Select one or more representative display panels as samples. Set N preset grayscale levels, such as... Figure 4 As shown, for example, five preset gray levels (g=16, 32, 64, 128, 192) are used to acquire brightness images of gray levels 16, 32, 64, 128, and 192 in the R, G, and B channels, respectively. Brightness data is then obtained from these brightness images. Generally, the more gray level points selected, the higher the fitting accuracy. Preferably, at least five points evenly distributed within the 0-255 gray level range are selected, with a focus on increasing sampling points in low and high gray level regions to better capture dark details and bright saturation characteristics.

[0053] The driving sample display panel displays pure red, green and blue images at the above N gray levels. A black and white camera records the brightness data of each sub-display area of ​​the sample display panel. Based on the brightness data of each sub-display area, the first sub-mapping parameter, the second sub-mapping parameter and the third sub-mapping parameter of that sub-display area are calculated.

[0054] To further improve the mapping accuracy of the first mapping relationship and the second mapping relationship, embodiments of this application may also perform the acquisition method of the first mapping parameter, the second mapping parameter and the third mapping parameter for multiple sample display panels, to acquire the first mapping parameter, the second mapping parameter and the third mapping parameter of multiple sample display panels; calculate the weighted average of multiple first mapping parameters as the final first mapping parameter, calculate the weighted average of multiple second mapping parameters as the final second mapping parameter, and calculate the weighted average of multiple third mapping parameters as the final third mapping parameter.

[0055] Specifically, K blocks (e.g., K=50), i.e., 50 display panels randomly selected from the normal production line, are selected as samples. For each sample display panel, steps one and two above are performed to obtain the brightness dataset of each sub-display area i on the display panel. Then, based on the brightness dataset of sub-display area i of each sample display panel, the first sub-mapping parameter, the second sub-mapping parameter, and the third sub-mapping parameter of sub-display area i are calculated. The weighted average of each sub-mapping parameter of sub-display area i of the 50 sample display panels is calculated to obtain the final first mapping parameter, second mapping parameter, and third mapping parameter.

[0056] By averaging the mapping parameters of multiple sample panels, the resulting first, second, and third mapping parameters can represent the typical statistical characteristics of the display panel of that model. This allows for stable and highly accurate brightness data estimation results when applied to a large number of panels to be compensated.

[0057] In another embodiment of this application, the second sub-mapping parameter is obtained in the following manner: The brightness of the sub-display area of ​​the sample display panel under the first gray level and the second gray level is measured in the first color channel, the second color channel and the third color channel. The second mapping parameter is calculated based on the following formula: γ1=γ R / γ G , γ2=γ B / γ G ; γ G =log[Lv_G(X) / Lv_G(Y)] / log(X); γ R =log[Lv_R(X) / Lv_R(Y)] / log(X); γ B =log[Lv_B(X) / Lv_B(Y)] / log(X); Where Lv_G(X) is the first grayscale brightness of the first color channel, and Lv_G(Y) is the second grayscale brightness of the first color channel; Lv_R(X) is the first grayscale brightness of the second color channel, and Lv_R(Y) is the second grayscale brightness of the second color channel; Lv_B(X) is the first grayscale brightness of the third color channel, and Lv_B(Y) is the second grayscale brightness of the third color channel, γ G Indicates the gamma value of the first color channel; γ R γ represents the gamma value of the second color channel. B γ represents the gamma value of the third color channel. 1、 γ2 is the second mapping parameter.

[0058] Specifically, the first gray level X can be near the middle gray level, and the second gray level Y can be near the maximum gray level. That is, the first gray level can be 40%-60% gray level, for example, it can be 40%, 45%, 50%, 55% or 60% gray level; the second gray level can be 90%-100% gray level, for example, it can be 90%, 95%, 96%, 98% or 100% gray level.

[0059] In a preferred implementation, the first gray level X can be 50% gray level and the second gray level Y can be 100% gray level, so the brightness of the sub-display area of ​​the sample display panel under the first color channel, the second color channel and the third color channel can be measured at 50% gray level and 100% gray level. The second mapping parameter is calculated based on the following formula: γ1=γ R / γ G , γ2=γ B / γ G ; γ G =log[Lv_G(0.5) / Lv_G(1)] / log(0.5); γ R =log[Lv_R(0.5) / Lv_R(1)] / log(0.5); γ B =log[Lv_B(0.5) / Lv_B(1)] / log(0.5); Wherein, Lv_G(0.5) is the 50% grayscale brightness of the first color channel, and Lv_G(1) is the 100% grayscale brightness of the first color channel; Lv_R(0.5) is the 50% grayscale brightness of the second color channel, and Lv_R(1) is the 100% grayscale brightness of the second color channel; Lv_B(0.5) is the 50% grayscale brightness of the third color channel, and Lv_B(1) is the 100% grayscale brightness of the third color channel; γ G Indicates the gamma value of the first color channel; γ R γ represents the gamma value of the second color channel. B This represents the gamma value of the third color channel.

[0060] The first sub-mapping parameter mentioned above is obtained in the following way: Obtain the maximum brightness of the sub-display area of ​​the sample display panel under the first color channel, the second color channel, and the third color channel; The first sub-mapping parameter is calculated based on the following formula: α1=Lv_R_max / (Lv_G_max)^γ1; α2=Lv_B_max / (Lv_G_max)^γ2; Where Lv_G_max is the maximum brightness in the first color channel, Lv_R_max is the maximum brightness in the second color channel, and Lv_B_max is the maximum brightness in the third color channel.

[0061] In this embodiment of the application, the brightness can be expressed as follows at any gray level g (normalized to [0,1]): Lv_R(g)=Lv_R_max g)^γ R Lv_G(g) = Lv_G_max (g)^γ G Lv_B(g) = Lv_B_max (g)^γ B Where, γ G γ B and γ R These represent the gamma values ​​for each color channel, and Lv_R_max, Lv_G_max, and Lv_B_max represent the maximum brightness values ​​for each color channel.

[0062] Substituting the above brightness expression formula into the first mapping relationship Lv_R(g)=α1 [Lv_G(g)]^γ1+β1, we can derive: Lv_R_max g^{γ R}=α1 (Lv_G_max g^{γ G})^γ1+γ B When the maximum gray level g=1, we can derive from the above formula: Lv_R_max=α1 (Lv_G_max)^γ1+β1 When the minimum gray level g=0, we can derive from the above formula: 0=α1 0 + β1, that is, β1 = 0.

[0063] In other words, Lv_R_max=α1 (Lv_G_max)^γ1 When the intermediate gray level g=0.5, the color shift of the panel mainly comes from the difference in γ value, then: γ R ≈γ G γ1 That is, we can obtain: α1=Lv_R_max / (Lv_G_max)^γ1, γ1=γ R / γ G ; Similarly, we can obtain: α2 = Lv_B_max / (Lv_G_max)^γ2, γ2 = γ B / γ G ; γG γ R and γ B The value can be calculated based on the brightness values ​​at 50% and 100% gray levels: That is to say: γ G =log[Lv_G(0.5) / Lv_G(1)] / log(0.5); γ R =log[Lv_R(0.5) / Lv_R(1)] / log(0.5); γ B =log[Lv_B(0.5) / Lv_B(1)] / log(0.5).

[0064] This embodiment only requires measuring RGB brightness at 100% grayscale and 50% grayscale, and only requires measuring 2-3 grayscale levels in total to complete the calibration of the first and second mapping parameters, which significantly reduces the amount of brightness data measurement.

[0065] It is understandable that after determining the first and second mapping parameters through the methods described in the above embodiments, in order to ensure the accuracy of brightness mapping, it is also necessary to consider the light leakage of the display panel in the dark state. Therefore, this application embodiment also provides a method for obtaining the third mapping parameter for light leakage compensation, specifically obtained through the following methods: Obtain the color coordinates of the sub-display area of ​​the sample display panel at the maximum gray level, and calculate the deviation value Δu'v' between the measured value and the standard value of the color coordinates; The third sub-mapping parameter is calculated based on the following formula: β1=k1 Δu'v'; β2=k2 Δu'v'; Where k1 and k2 are adjustment coefficients.

[0066] Specifically, the standard value of each sub-display area of ​​the display panel at the maximum grayscale can be obtained, denoted as (u'_target, v'_target). Then, the color coordinate measurement value of the sub-display area of ​​the display panel at the maximum grayscale can be measured using a colorimeter or spectrometer, denoted as (u'_meas, v'_meas). Finally, the Euclidean distance between the actual value and the standard value can be calculated. Δu'v'

[0067] Δu'v' reflects the degree of white field chromaticity shift of the display panel at maximum grayscale. This shift is usually caused by the relative brightness ratio of red, green, and blue sub-pixels deviating from the design value. This deviation also affects the color performance of dark states at low grayscale levels. Therefore, the third mapping parameter can be set to β1=k1. Δu'v';β2=k2 Δu'v'; k1 and k2 are adjustment coefficients, whose values ​​are determined through experience or experimentation.

[0068] The third mapping parameter reflects light leakage or minimum luminance in the dark state, and light leakage in the dark state directly affects the chromaticity performance at low gray levels. The third mapping parameter is calculated by the chromaticity coordinate deviation Δu'v' at the maximum gray level, and a correlation model between high gray level chromaticity characteristics and low gray level bias parameters is established, making the parameter calibration more reasonable.

[0069] This application embodiment also provides a display panel compensation method, which obtains brightness data according to any of the brightness data methods described above, generates brightness compensation data, and performs brightness compensation on the display panel.

[0070] Understandably, the goal of brightness compensation is to calculate the compensation value for each pixel to achieve uniform brightness on the display panel. In one implementation, a target brightness can be predetermined, with the compensation aiming to correct the Mura area to match the brightness of the normal area. The target brightness value can typically be the brightness of a specific display area (such as a reference point) selected from the display panel as a standard. Alternatively, a desired target brightness can be set in a mathematical model based on multi-channel, multi-grayscale brightness data obtained in the above embodiments. The core principle of brightness compensation is to compare the collected actual brightness with the desired target brightness, and then calculate the compensation value for each pixel using the grayscale-brightness relationship formula (i.e., the gamma model). Methods can be divided into brightness domain compensation: directly calculating the difference in the brightness domain (usually in nits) and then converting it back to the grayscale domain; and grayscale domain compensation: directly adjusting the mapping in the grayscale domain (0-255), for example, adjusting the ratio based on the deviation.

[0071] Furthermore, based on algorithm complexity and performance requirements, sub-pixel compensation can be categorized into several implementation paths: Theoretically, the most accurate method calculates an independent compensation value for each sub-pixel, but this involves a large amount of data. Alternatively, block-based compensation can be used: dividing the screen into multiple blocks and calculating uniform compensation parameters for each block to reduce data volume and processing complexity.

[0072] This application also provides a display device, including any of the display panels described in the above embodiments, wherein the display device can be an electronic device such as a smartphone, tablet computer, or laptop computer.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for acquiring brightness data of a display panel, characterized in that, The method includes: Obtain the brightness data of the display panel to be compensated in the first color channel; The brightness data of the display panel in the second color channel is calculated according to the first mapping relationship; the first mapping relationship is a pre-established mapping relationship between the brightness values ​​of the first color channel and the second color channel; The brightness data of the display panel in the third color channel is calculated based on the second mapping relationship; the second mapping relationship is a pre-established brightness value mapping relationship between the first color channel and the third color channel.

2. The method according to claim 1, characterized in that, Both the first mapping relationship and the second mapping relationship include a first mapping parameter, a second mapping parameter, and a third mapping parameter. The first mapping parameter of the first mapping relationship has a different value than the first mapping parameter of the second mapping relationship. The second mapping parameter of the first mapping relationship has a different value than the second mapping parameter of the second mapping relationship. The third mapping parameter of the first mapping relationship has a different value than the third mapping parameter of the second mapping relationship.

3. The method according to claim 2, characterized in that, The display panel includes multiple sub-display areas. At least one of the first mapping relationship and the second mapping relationship includes multiple sub-mapping relationships. The multiple sub-mapping relationships of the first mapping relationship and the second mapping relationship correspond one-to-one with the multiple sub-display areas. Each sub-mapping relationship includes a first sub-mapping parameter, a second sub-mapping parameter, and a third sub-mapping parameter. The step of calculating the brightness data of the display panel in the second color channel according to the first mapping relationship includes: The brightness data of each sub-display area of ​​the display panel in the second color channel is calculated based on the multiple sub-mapping relationships included in the first mapping relationship; The step of calculating the brightness data of the display panel in the third color channel according to the second mapping relationship includes: The brightness data of each sub-display area of ​​the display panel in the third color channel is calculated based on the multiple sub-mapping relationships included in the second mapping relationship.

4. The method according to claim 3, characterized in that, The first mapping relationship includes: Lv_R(g)=α1 [Lv_G(g)]^γ1+β1; the second mapping relationship includes: Lv_B(g)=α2 [Lv_G(g)]^γ2+β2; Wherein, Lv_G(g) represents the brightness value of the first color channel at gray level g; Lv_R(g) represents the brightness value of the second color channel at gray level g; Lv_B(g) represents the brightness value of the third color channel at gray level g; the first mapping parameters include α1 and α2, representing brightness scaling factors; the second mapping parameters include γ1 and γ2, representing nonlinear exponents; and the third mapping parameters include β1 and β2, representing bias parameters.

5. The method according to claim 4, characterized in that, The first mapping parameter, the second mapping parameter, and the third mapping parameter are obtained in the following way: The brightness of multiple sub-display areas of the sample display panel under multiple preset gray levels is obtained in the first color channel, the second color channel, and the third color channel. Based on the brightness of each sub-display area under multiple preset gray levels and the first, second, and third color channels, the first, second, and third sub-mapping parameters corresponding to each sub-display area are calculated to obtain the first, second, and third mapping parameters of the display panel.

6. The method according to claim 5, characterized in that, The first mapping parameter, the second mapping parameter, and the third mapping parameter are obtained by performing the first mapping parameter, the second mapping parameter, and the third mapping parameter on multiple sample display panels in an acquisition manner; Calculate the weighted average of multiple first mapping parameters as the final first mapping parameter, calculate the weighted average of multiple second mapping parameters as the final second mapping parameter, and calculate the weighted average of multiple third mapping parameters as the final third mapping parameter.

7. The method according to claim 5, characterized in that, The second mapping parameter is obtained in the following way: The brightness of the sub-display area of ​​the sample display panel under the first gray level and the second gray level is measured in the first color channel, the second color channel and the third color channel. The second mapping parameter is calculated based on the following formula: γ1=γ R / c G ,γ2=γ B / c G ; γ G =log[Lv_G(X) / Lv_G(Y)] / log(X); γ R =log[Lv_R(X) / Lv_R(Y)] / log(X); γ B =log[Lv_B(X) / Lv_B(Y)] / log(X); Where Lv_G(X) is the first grayscale brightness of the first color channel, and Lv_G(Y) is the second grayscale brightness of the first color channel; Lv_R(X) is the first grayscale brightness of the second color channel, and Lv_R(Y) is the second grayscale brightness of the second color channel; Lv_B(X) is the first grayscale brightness of the third color channel, and Lv_B(Y) is the second grayscale brightness of the third color channel, γ G Indicates the gamma value of the first color channel; γ R γ represents the gamma value of the second color channel. B γ represents the gamma value of the third color channel. 1、 γ2 is the second mapping parameter.

8. The method according to claim 7, characterized in that, The first mapping parameter is obtained in the following way: Obtain the maximum brightness of the sub-display area of ​​the sample display panel under the first color channel, the second color channel, and the third color channel; The first mapping parameter is calculated based on the following formula: α1=Lv_R_max / (Lv_G_max)^γ1; α2=Lv_B_max / (Lv_G_max)^γ2; Where Lv_G_max represents the maximum brightness in the first color channel, Lv_R_max represents the maximum brightness in the second color channel, and Lv_B_max represents the maximum brightness in the third color channel, γ 1、 γ2 is the second mapping parameter.

9. The method according to claim 5, characterized in that, The third mapping parameter is obtained in the following way: Obtain the color coordinates of the sub-display area of ​​the sample display panel at the maximum gray level, and calculate the deviation value Δu'v' between the measured value and the standard value of the color coordinates; The third mapping parameter is calculated based on the following formula: β1=k1 Δu'v'; β2=k2 Δu'v'; Where k1 and k2 are adjustment coefficients.

10. A display panel compensation method, characterized in that, Brightness data is obtained according to any one of the brightness data methods described in claims 1-9, and brightness compensation data is generated to perform brightness compensation on the display panel.

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