WO2025222510A1 - Display device, voltage drop compensation method and electronic device - Google Patents

Abstract

A display device (2401), a voltage drop compensation method and an electronic device. The display device (2401) comprises a display screen (200, 1900) and a control circuit (201, 1901), wherein the display screen (200, 1900) is configured to display content; the control circuit (201, 1901) comprises a processor (2200, 2300) and a memory (2201, 2301), and the processor (2200, 2300) is used for reading a program in the memory (2201, 2301) and executing the following steps: acquiring a compensation parameter and a brightness parameter of the display screen (200, 1900), wherein the compensation parameter and the brightness parameter are determined on the basis of the display characteristics of the display screen (200, 1900) (step 2000); on the basis of the compensation parameter, determining a compensation coefficient of each channel grayscale of at least one pixel unit in a current image displayed on the display screen (200, 1900) (step 2001); using the brightness parameter to adjust the compensation coefficient of each channel grayscale of the pixel unit to obtain a compensation adjustment coefficient of each channel grayscale of the pixel unit (step 2002); and using the compensation adjustment coefficient of each channel grayscale of the pixel unit to compensate for each channel grayscale of the pixel unit, and displaying the compensated current image (step 2003).

Description

Display devices, voltage drop compensation methods, and electronic equipment Technical Field

This disclosure relates to the field of display technology, and in particular to a display device, a voltage drop compensation method, and an electronic device.

Background Technology

Voltage drop is a type of screen brightness uniformity problem caused by the resistance of the drive circuit. The brightness uniformity of a display screen stems from an inherent property of the screen itself, specifically the voltage unevenness caused by the resistance of the drive circuit. The light-emitting pixels in a display screen are connected through a drive circuit. The resistance inherent in the drive circuit causes voltage division, resulting in inconsistent drive voltages for each pixel and thus inconsistent luminous intensity, leading to screen brightness uniformity. Simultaneously, differences in the display's on-pixel ratio (OPR) can also cause brightness variations in the displayed image and inconsistent brightness of white areas.

Summary of the Invention

This disclosure provides a display device, a voltage drop compensation method, and an electronic device for compensating for brightness differences caused by different global loads, and for adjusting the compensated brightness under different loads to adapt to different usage scenarios.

In a first aspect, embodiments of the present disclosure provide a display device, which includes a display screen and a control circuit, wherein:

The display screen is configured to display content;

The control circuit includes a processor and a memory. The memory stores programs executable by the processor, and the processor reads the programs from the memory and performs the following steps:

Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen;

Based on the compensation parameters, at least one pixel unit in the current image displayed on the screen is determined to be... The compensation coefficient for grayscale levels;

The compensation coefficients of the grayscale of each channel of the pixel unit are adjusted using the brightness parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

The gray levels of each channel of the pixel unit are compensated using the compensation adjustment coefficients of each channel, and the compensated current image is then displayed.

In a second aspect, embodiments of this disclosure provide a display device, which includes a display screen and a control circuit, wherein:

The display screen is configured to display content;

The control circuit includes a processor and a memory. The memory stores programs executable by the processor, and the processor reads the programs from the memory and performs the following steps:

Acquire the current image and determine the input load on the display screen when the current image is displayed;

Based on the sub-linear relationship corresponding to the input load among n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load;

The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1.

Thirdly, the voltage drop compensation method provided in this disclosure includes:

Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen;

The compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen are determined based on the compensation parameters.

The compensation coefficients of the grayscale of each channel of the pixel unit are adjusted using the brightness parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

The gray levels of each channel of the pixel unit are compensated using the compensation adjustment coefficients of each channel, and the compensated current image is then displayed.

Fourthly, the voltage drop compensation method provided in this disclosure includes:

Acquire the current image and determine the input load on the display screen when the current image is displayed;

The sub-linear relationship corresponding to the input load in the n sub-linear relationships based on load and compensated brightness. The system determines the compensation brightness corresponding to the input load;

The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1.

Fifthly, embodiments of this disclosure also provide an electronic device, including a processor and a memory, the memory being used to store a program executable by the processor, and the processor being used to read the program in the memory and execute the method described in any one of the first, second, or third aspects.

Sixthly, embodiments of this disclosure also provide a voltage drop compensation system, including a control device and a display device;

The control device is used to determine the compensation parameters and brightness parameters corresponding to the display screen of the display device, and write the compensation parameters and brightness parameters into the driver chip of the display device; wherein the compensation parameters and brightness parameters are determined according to the display characteristics of the display screen;

The display device is used to determine the compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the display screen according to the compensation parameters; adjust the compensation coefficients for each channel grayscale of the pixel unit using the brightness parameters to obtain the compensation adjustment coefficients for each channel grayscale of the pixel unit; compensate for each channel grayscale of the pixel unit using the compensation adjustment coefficients for each channel grayscale of the pixel unit, and display the compensated current image.

In a seventh aspect, embodiments of this disclosure also provide a computer storage medium having a computer program stored thereon, which, when executed by a processor, is used to implement the steps of the method described in any one of the first, second, or third aspects above.

Eighthly, this disclosure provides a computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the method described in any one of the first, second, or third aspects.

These or other aspects of this disclosure will become more apparent in the following description of embodiments.

Attached Figure Description

To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are merely illustrative of this disclosure. The embodiments described herein allow those skilled in the art to obtain other drawings based on these drawings without any creative effort.

Figure 1 is a schematic diagram of the difference in screen brightness caused by voltage drop according to an embodiment of this disclosure;

Figure 2 is a schematic diagram of a display device provided in an embodiment of this disclosure;

Figure 3 is a schematic diagram showing that the brightness decreases as the average current intensity increases, according to an embodiment of this disclosure.

Figure 4 is a schematic diagram of a second linear relationship between the brightness of a pure white image and the current intensity according to an embodiment of this disclosure;

Figure 5 is a schematic diagram of the grayscale images of each channel of a first test image provided in an embodiment of this disclosure;

Figure 6 is a schematic diagram of a second test image provided in an embodiment of this disclosure;

Figure 7 is a schematic diagram of a first linear relationship provided in an embodiment of this disclosure;

Figure 8 is a schematic diagram of a third test image provided in an embodiment of this disclosure;

Figure 9 is a schematic diagram of a first relationship curve between gray levels and minimum brightness of each channel provided in an embodiment of this disclosure;

Figure 10 is a schematic diagram of a linear relationship between a compensation coefficient and maximum brightness provided in an embodiment of this disclosure;

Figure 11 is a schematic diagram of the relationship between load and compensation coefficient under an HBM mode provided in an embodiment of this disclosure;

Figure 12 is a schematic diagram of a compensation effect provided in an embodiment of this disclosure;

Figure 13 is a schematic diagram of an automatic compensation system provided in an embodiment of this disclosure;

Figure 14 is a schematic diagram of a compensation algorithm design provided in an embodiment of this disclosure;

Figure 15 is a flowchart of IP data for a compensation algorithm provided in an embodiment of this disclosure;

Figure 16 is a flowchart of the software and hardware deployment for updating compensation parameters and brightness parameters provided in an embodiment of this disclosure;

Figure 17 is a flowchart of a compensation parameter and brightness parameter update provided in an embodiment of this disclosure;

Figure 18 is a flowchart of a voltage drop compensation method in a high-brightness mode provided in an embodiment of this disclosure;

Figure 19 is a schematic diagram of a display device provided in an embodiment of this disclosure;

Figure 20 is a flowchart of an implementation method for voltage drop compensation provided in an embodiment of this disclosure;

Figure 21 is a flowchart of an implementation method for voltage drop compensation provided in an embodiment of this disclosure;

Figure 22 is a schematic diagram of an electronic device provided in an embodiment of this disclosure;

Figure 23 is a schematic diagram of an electronic device provided in an embodiment of this disclosure;

Figure 24 is a schematic diagram of a voltage drop compensation system provided in an embodiment of this disclosure;

Figure 25 is a schematic diagram of a voltage drop compensation device provided in an embodiment of this disclosure;

Figure 26 is a schematic diagram of a voltage drop compensation device provided in an embodiment of this disclosure.

Detailed Implementation

To make the objectives, technical solutions, and advantages of this disclosure clearer, the disclosure will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

In this disclosure, the term "and/or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent three cases: A alone, A and B simultaneously, and B alone. The character "/" generally indicates that the preceding and following related objects have an "or" relationship.

The application scenarios described in this disclosure are for the purpose of more clearly illustrating the technical solutions of this disclosure and do not constitute a limitation on the technical solutions provided in this disclosure. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided in this disclosure are also applicable to similar technical problems. In the description of this disclosure, unless otherwise stated, "multiple" means two or more.

Before introducing the display device and voltage drop compensation method provided in the embodiments of this disclosure, the technical background of the embodiments of this disclosure will be described in detail below for ease of understanding.

Voltage drop is a problem of uneven screen brightness caused by the resistance of the driving circuit. The uneven brightness of the display stems from an inherent property of the screen itself, namely, the uneven voltage caused by the resistance of the driving circuit. This is particularly relevant to OLED (Organic Light-Emitting Diode) displays. Taking an organic light-emitting diode (OLED) screen as an example, the light-emitting pixels in the display are connected through a driving circuit. The resistance inherent in the driving circuit itself causes voltage division, resulting in inconsistent driving voltages for each light-emitting pixel, leading to inconsistent luminous intensity and thus uneven screen brightness. Generally, the closer to the starting point of the driving circuit, the smaller the voltage division and the higher the brightness. Simultaneously, different global loads also result in significant differences in screen brightness. As shown in Figure 1, this embodiment provides a schematic diagram of screen brightness differences caused by voltage drop, where different loads lead to brightness differences in the displayed image, and inconsistent brightness of the white screen.

Based on this, this disclosure provides a display device and a voltage drop compensation method to compensate for brightness differences caused by different loads and inconsistent brightness of the white screen itself, achieving brightness consistency under different loads. Furthermore, this embodiment can determine corresponding compensation parameters and brightness parameters based on the display characteristics of different displays, and calculate compensation coefficients and adjustment coefficients using the corresponding compensation and brightness parameters of the display, thereby achieving voltage drop compensation. Not only can it achieve brightness consistency under different loads, but it can also adjust the degree of compensation based on different loads in different usage scenarios, improving the compensated brightness under low loads and achieving localized brightening, for example, it can be applied to fingerprint unlocking scenarios or menu clicking scenarios.

This embodiment provides a display device and voltage drop compensation method. The core idea is to obtain compensation parameters and brightness parameters specific to the current display screen. Since different display screens have different display characteristics, this embodiment can specifically determine the compensation and brightness parameters applicable to the current display screen first. Grayscale compensation and adjustment are then performed using the corresponding brightness and compensation parameters for that display screen. By obtaining compensation and brightness parameters for different display screens, mass production upgrades of screens can be facilitated, enabling batch acquisition of compensation and brightness parameters for different display screens and improving production efficiency. The display screen can compensate and adjust the displayed image based on the corresponding compensation and brightness parameters, improving the accuracy of compensation and enhancing the display effect. Furthermore, it can perform localized brightening for different usage scenarios, improving the user experience.

It should be noted that the display devices in this embodiment include, but are not limited to, large-screen smart display devices (generally 50 inches or larger), mobile phones, tablets, computers, and other devices using LCD screens. These display devices include, but are not limited to, liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs). Displays such as Organic Electroluminescence Display (OLED) and e-ink displays are used. This embodiment does not impose excessive limitations on the type of display screen used in the display device.

The display screen of the display device in this embodiment includes, but is not limited to, OLED, mobile phone screen, vehicle screen, NB (Notebook) screen, etc. This embodiment does not impose too many limitations on it.

As shown in Figure 2, this embodiment of the present disclosure provides a display device, which includes a display screen 200 and a control circuit 201, wherein:

The display screen 200 is configured to display content;

The control circuit 201 includes a processor and a memory. The memory stores programs executable by the processor, and the processor reads the programs from the memory and performs the following steps:

Step a: Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen;

In some embodiments, the compensation parameters in this embodiment are used to compensate for grayscale under different loads, and the brightness parameters in this embodiment are used to adjust the degree of compensation for grayscale under different loads.

Optionally, the display characteristics of the display screen are used to represent and display related features or parameters. The display characteristics of the display screen include, but are not limited to, the size of the display area of the display screen, the adjustable range of the brightness of the display screen, the maximum brightness of the display screen, DBV (Display Brightness Values), whether it is in a high brightness mode (such as HBM mode), etc. This embodiment does not impose too many limitations on these.

In some embodiments, the processor of this embodiment is specifically configured to obtain the compensation parameters and brightness parameters of the display screen from the driver chip; different displays screens have different compensation parameters, and/or different displays screens have different brightness parameters.

In practice, the compensation parameters and brightness parameters of the display screen can be tested and calculated by an external device such as a PC. The calculated compensation parameters and brightness parameters are then written into the driver chip, so that the display device can achieve image brightness compensation based on the compensation parameters and brightness parameters related to its own display characteristics.

Step b: Determine the compensation coefficient for each channel grayscale of at least one pixel unit in the current image displayed on the screen according to the compensation parameters;

Optionally, the pixel unit in this embodiment can be a single pixel or adjacent pixels. Pixel combination is not limited in this embodiment.

It should be noted that in this embodiment, after obtaining the compensation parameters and brightness parameters of the display device using a PC, the parameters are written into the driver chip of the display device. When the display device is performing compensation, one example is that the display device determines the compensation coefficient of each channel grayscale of at least one pixel unit in the current image displayed on the screen according to the compensation parameters, and uses the compensation coefficient to compensate for the grayscale of each channel.

Optionally, the images input to the display screen in this embodiment (including the current image and test images, etc.) include, but are not limited to, RGB images, RAW images, YUV images, etc. This embodiment does not impose too many restrictions on the image format.

Optionally, this embodiment can determine the compensation coefficient using commonly used methods or the method provided in this embodiment; this embodiment does not impose excessive limitations on this method. Regardless of the method used to determine the compensation coefficient, this embodiment will adjust the determined compensation coefficient using brightness parameters, thereby using the compensation adjustment coefficient for subsequent image compensation processing. This allows for different adjustment levels based on the characteristics of different displays, achieving adjustable voltage drop compensation and providing a more accurate compensation solution. Furthermore, the compensation parameters and brightness parameters in this embodiment are determined based on the display characteristics of the display screen, which can facilitate screen mass production upgrades and improve production efficiency.

In some embodiments, the processor of this embodiment is specifically configured to determine the compensation coefficient through the following steps:

Step b1: Based on the compensation parameters, estimate the input load and maximum load of the pixel unit in the current image, where the maximum load represents the input load of the grayscale image generated using the maximum value of each channel grayscale of the pixel unit.

For a display screen, the load is related to the displayed image. The larger the load, the greater the current intensity. The load and current intensity are positively correlated. Therefore, this embodiment uses the current intensity to detect the magnitude of the input load corresponding to the current image.

Optionally, the current intensity in this embodiment includes the global current intensity for the display screen, and/or the average current intensity for a single pixel unit of the display screen, wherein the global current intensity / display area = the average current intensity of a single pixel.

The current intensity (including the current current intensity and the target current intensity) in this embodiment includes for The current intensity refers to one or more of the following: global current intensity for the display screen, average current intensity for a single pixel unit of the display screen, and average current intensity for a combination of pixel units of the display screen, wherein global current intensity / display area = average current intensity; a pixel unit includes a single pixel, or a pixel area defined according to other rules, which is not limited in this embodiment. Optionally, the current current intensity includes the current average current intensity and the current global current intensity; the target current intensity includes the target average current intensity and the target global current intensity.

In practice, to facilitate the calculation of the average current intensity corresponding to each channel grayscale for each pixel unit, this embodiment typically uses the current average current intensity and the target average current intensity during the algorithm calculation process. That is, for each channel grayscale of a single pixel unit, the corresponding current average current intensity and target average current intensity are calculated.

In some embodiments, the compensation parameters in this embodiment include channel coefficient parameters and channel exponential parameters. In practice, the channel coefficient parameters and exponential parameters are obtained in advance by detecting the current display screen based on a test image. Specifically, the channel coefficient parameters are determined using a pre-set first test image, and the channel exponential parameters are determined using a pre-set second test image.

Optionally, the input load can be determined as follows:

Based on the grayscale, coefficient parameters, and exponential parameters of each channel of the pixel unit in the current image, the input load of the pixel unit is estimated.

In practice, based on the grayscale, coefficient parameters, and exponential parameters of each channel of the pixel unit in the current image, the current average current intensity of the pixel unit is estimated. This current average current intensity of the pixel unit is then used as the input load of the pixel unit.

It should be noted that for any input image, the overall load of the image is first calculated and expressed as the average current intensity (such as the current average current intensity). The higher the average current intensity, the greater the load, the more severe the voltage drop in the circuit, and the greater the decrease in brightness. As shown in Figure 3, this embodiment also provides a schematic diagram of the decrease in brightness as the average current intensity increases, showing that brightness is negatively correlated with the average current intensity.

In practice, the current average current intensity (i.e., current magnitude, measured in amperes (A)) is mainly related to the pixels and image size of the image input to the screen. The current average current intensity is estimated using the following formula. count.

In formula (1), is represents the current average current intensity, c represents any channel in the multi-channel image, taking RGB image as an example, c = 0, 1, 2; cw _c represents the coefficient parameter of channel c (such as R channel, G channel, B channel); γ _c represents the exponential parameter of channel c; In _c (x,y) represents the gray level value of channel c at pixel position (x,y) in the input image (i.e., the current image) (value range 0~1). h represents the height of the current image (i.e., the number of pixels in the Y-axis direction), and w represents the width of the current image (i.e., the number of pixels in the X-axis direction).

It should be noted that, for ease of calculation, this embodiment normalizes the grayscale values of each channel within a pixel unit, ensuring that the grayscale values of each channel within a pixel unit range from 0 to 1. As can be seen from the above formula, the current average current intensity changes exponentially with the grayscale value.

Optionally, the maximum load can be determined as follows:

The maximum load of the pixel unit is estimated by using the grayscale values of each channel of the grayscale image generated based on the maximum grayscale values of each channel of the pixel unit, the grayscale values of each channel, the coefficient parameters of each channel, and the exponent parameters of each channel; wherein the grayscale image represents an image with the same grayscale values in each channel.

In practice, a grayscale image is generated based on the maximum grayscale value of each channel of the pixel unit. At this time, the grayscale values of each channel in the grayscale image are the same. Based on the grayscale values of each channel, the coefficient parameters of each channel, and the exponent parameters of each channel in the grayscale image, the target current intensity of the pixel unit is estimated. The target current intensity is used as the maximum load of the pixel unit.

In this embodiment, the target average current intensity is typically used for subsequent algorithm calculations. The target average current intensity is applied to each pixel unit in the grayscale image. That is, each pixel unit in the grayscale image corresponds to a target average current intensity. The grayscale of the entire image is compensated by compensating the grayscale value of each pixel unit.

In implementation, the grayscale image is determined based on the current image. For any input RGB grayscale ( _k0 , _k1 , _k2 ), its target brightness depends on its target average current intensity is'. Since voltage drop compensation cannot change the screen's gamma characteristic, that is, when the entire screen is lit up with grayscale ( _k0 = _k1 = _k2 ), the grayscale value is not changed by the voltage drop compensation algorithm. Therefore, this invention proposes a method for determining the target average current. The intensity method selects the maximum value max( _k0 , _k1 , _k2 ) among the grayscale values _k0 , _k1 , _k2 of each channel (R channel, G channel, and B channel) for a pixel unit. The average current intensity is' corresponding to the input grayscale ( _k0 , _k1 , _{k2 )} when the _entire screen is lit up is the target average _current intensity.

In practice, the target average current intensity (i.e., current magnitude, in amperes A) is mainly related to the pixels and image size of the grayscale image. The target average current intensity is estimated using the following formula.

In formula (2), is′ represents the target average current intensity, c represents any channel in the multi-channel image, taking RGB image as an example, c＝0,1,2; cw _c represents the coefficient parameter of channel c (such as R channel, G channel, B channel); γ _c represents the exponential parameter of channel c; max(k ₀ ,k ₁ ,k ₂ ) represents the maximum value of gray level values of each channel at pixel position (x,y) of each pixel unit of the input gray-scale image (value range 0～1). h represents the height of the input gray-scale image (i.e. the number of pixels in the Y-axis direction), and w represents the width of the input gray-scale image (i.e. the number of pixels in the X-axis direction).

In practice, the height of the grayscale image is the same as the height of the current image, and the width of the grayscale image is the same as the width of the current image.

It should be noted that, for ease of calculation, this embodiment normalizes the grayscale values of each channel within a pixel unit, ensuring that the grayscale values of each channel within a pixel unit range from 0 to 1. As can be seen from the above formula, the current average current intensity changes exponentially with the grayscale value.

In some embodiments, the average current intensity is calculated using the coefficient parameters and index parameters of each channel in both formulas (1) and (2). In this embodiment, the parameters involved are calculated in the following manner.

The compensation parameters in this embodiment include channel coefficient parameters; the channel coefficient parameters are determined based on the load corresponding to the preset area of the grayscale image of each channel in the first test image, and the proportion of the preset area to the display area of the grayscale image of each channel; the load corresponding to the preset area is determined based on the second linear relationship between the brightness of the pure white image and the load.

The first test image includes grayscale images of each channel, and each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image.

In practice, the coefficient parameters are determined as follows:

1) Determine the second linear relationship between the brightness and load of a pure white image; determine a first test image, the first test image including grayscale images of each channel, each grayscale image including a preset region and a non-preset region, the preset region being a pure white image, and the non-preset region being a non-pure white image; according to the second linear relationship, determine the load corresponding to the brightness of the preset region of each channel grayscale image in the first test image;

Optionally, the pure white image in this embodiment includes, but is not limited to, a white image, and the grayscale value of the pure white image is 255. It should be noted that the brightness and current intensity of the pure white image in this embodiment are linearly related. When the brightness and current intensity of other color images are also linearly related, this embodiment can also use other pure color images as the preset area in the first test image.

Optionally, the preset area of the first test image is pure white with a grayscale value of 255. The preset area occupies the same proportion of the display area of each channel's grayscale image. The grayscale values of the non-preset areas (background areas) of each channel's grayscale image in the first test image are the same, except for the preset area, and the grayscale value of the background area is 255. Optionally, in this embodiment, the preset area and the background area of the first test image have the same grayscale value.

2) Determine the coefficient parameters of each channel based on the load corresponding to the preset area of the grayscale image of each channel in the first test image, and the proportion of the preset area to the display area of the grayscale image of each channel.

The sum of the coefficient parameters corresponding to each channel is 1.

To obtain the parameter value of the average current intensity, this embodiment designs the following parameter measurement method:

2a) Using a pure white image with a grayscale value of 255, detect the correspondence between the brightness and the average current intensity of the pure white image, and fit the second linear relationship: lv＝a×is+b; where a and b are known parameters obtained from the fitting, is represents the average current intensity, and the current average current intensity or the target average current intensity can be substituted into the second linear relationship to obtain the corresponding brightness, and lv represents the brightness corresponding to each channel grayscale unit.

As shown in Figure 4, this embodiment provides a schematic diagram of the second linear relationship between the brightness of a pure white image and the current intensity. The horizontal axis represents the average current intensity, and the vertical axis represents the brightness. The brightness decreases linearly with the increase of the current intensity. Since the load and the current intensity are proportional, the brightness also decreases linearly with the increase of the load.

2b) As shown in Figure 5, this embodiment provides a schematic diagram of the grayscale images of each channel of the first test image, from left to right: the grayscale image of the R channel, the grayscale image of the G channel, and the grayscale image of the B channel. In each channel's grayscale image, a preset area is a pure white area with a grayscale value of 255. The preset area occupies p of the display area of the first test image. The grayscale images of each channel are displayed on the OLED screen, and then an optical acquisition device is used to collect the brightness of the center of the preset area, recording it as the brightness of the R channel sub-pixel lvR, the brightness of the G channel sub-pixel lvG, and the brightness of the B channel sub-pixel lvB. Then, the brightness of the preset area of each channel's grayscale image is substituted into the second linear relationship lv = a × is + b to obtain the corresponding current intensities, which are recorded as the average current intensity is _r of the R channel sub-pixel, the average current intensity is _g of the G channel sub-pixel, and the average current intensity is _b of the B channel sub-pixel.

(3) Determine the coefficient parameters corresponding to each channel using the following formula;

In formula (3), _CW0 , _CW1 and _CW2 represent the coefficient parameters of channels R, G and B respectively, p represents the proportion of the preset area to the display area of the first test image, and is _r , is _g and is _b represent the current intensity of channels R, G and B respectively (the average current intensity is used in the calculation).

In some embodiments, the compensation parameters in this embodiment include channel exponential parameters; the channel exponential parameters are determined based on the law that the load changes exponentially with the grayscale, according to the load corresponding to the grayscale value of the non-preset area in the grayscale image of each channel; the load corresponding to the grayscale value of the non-preset area is determined based on the second linear relationship between the brightness of the pure white image and the load, and by changing the grayscale value of the non-preset area in the grayscale image of each channel in the second test image, the correspondence between the grayscale value of the non-preset area in the grayscale image of each channel and the brightness of the preset area is obtained; the second test image includes grayscale images of each channel, each grayscale image of each channel includes a preset area and a non-preset area, the preset area is a pure white image, and the non-preset area is a non-pure white image.

The exponential parameter is determined by the following steps:

Step 1) Determine the second linear relationship between brightness and load in the pure white image; determine the second test image. The second test image includes grayscale images of each channel, and each channel grayscale image includes a preset area and a non-preset area. The preset area is a pure white image, and the non-preset area is a non-pure white image. The grayscale values of the non-preset areas in the grayscale images of each channel in the second test image are changed to determine the correspondence between the grayscale values of the non-preset areas in the grayscale images of each channel and the brightness of the preset areas.

Optionally, in this embodiment, the second test image is designed to include a preset area, wherein the preset area is a pure white image. To ensure the uniformity of the test, the preset area of the second test image is designed to be the same as the preset area of the first test image. For example, the preset area is pure white with a grayscale value of 255, and the size and position of the preset areas of the first and second test images are the same. The proportion of the preset area to the display area of the second test image is the same as the proportion of the preset area to the display area of the first test image.

Step 2) Based on the second linear relationship and the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in each channel grayscale image, determine the load corresponding to the grayscale values of non-preset areas in each channel grayscale image.

In practice, to calculate the exponential parameters of each channel, as shown in Figure 6, this embodiment provides a schematic diagram of a second test image. From top to bottom, these are the R-channel grayscale image group, the G-channel grayscale image group, and the B-channel grayscale image group. Each channel grayscale image group includes grayscale images with different grayscale levels. The preset area in each channel grayscale image is pure white with a grayscale level of 255. The proportion of the preset area to the display area of the second test image is p. The grayscale value k (where k takes values of 0.1, 0.2, 0.3, ..., 1) of the background area (non-preset area) of the RGB three channels of the second test image is changed. Then, the brightness of the center of the white area is tested. Substituting this into the second linear relationship formula between the brightness of the pure color image and the current intensity lv = a × is + b, the average current intensity of the RGB three channels at different grayscale levels k is obtained.

Step 3) Based on the exponential change of load with grayscale, determine the exponential parameters of each channel according to the load corresponding to the grayscale values of non-preset areas in the grayscale images of each channel.

In practice, the current intensity corresponding to each channel grayscale in the second test image changes exponentially with the grayscale. Based on this, the processor in this embodiment is specifically configured to determine the exponential parameters corresponding to each channel through the following steps:

3a) Based on the current intensity corresponding to the gray level of each channel of the pixel unit and the proportion of the preset area corresponding to each channel of the pixel unit to the display area of the second test image, the relationship curve between the gray level of each channel of the pixel unit and the current intensity is obtained by fitting.

Optionally, the current intensity corresponding to each channel grayscale of a pixel unit includes the average current intensity.

Optionally, the size and position of the preset area corresponding to each channel grayscale image are the same, and the proportion of the preset area corresponding to each channel grayscale image to the display area of the second test image is the same.

3b) Based on the relationship curve between grayscale and current intensity of each channel in a pixel unit, determine the exponential parameters corresponding to each channel.

Optionally, the current intensity includes the average current intensity.

In practice, after obtaining the current intensity corresponding to each channel grayscale of the second test image, the specific value of the exponent parameter can be obtained by curve fitting the exponent parameter and the current intensity corresponding to each channel grayscale. The formula is as follows:

In formula (4), k represents the grayscale value, p represents the proportion of the preset area to the display area of the second test image, and _CW0 , _CW1 and _CW2 represent the coefficient parameters of channel R, channel G and channel B respectively. γ _₀, γ_₁, and γ_₂ represent the average current intensity of channels R, G, and B at gray level k, respectively; γ₀, γ₁, and γ₂ represent the exponential parameters of channels R, G, and B, respectively.

Based on this, for any image input to the display screen, the current average current intensity and target average current intensity corresponding to the pixel unit in the input image can be calculated using the above formulas (1) and (2).

Step b2: Based on the first linear relationship between brightness and load at different gray levels, determine the current brightness of each channel gray level of the pixel unit under the input load and the target brightness under the maximum load by using linear interpolation.

In practice, after calculating the current average current intensity and target average current intensity for each channel of the current image, based on the first linear relationship between brightness and current intensity, linear interpolation is used. Determine the current brightness (for a single channel sub-pixel) corresponding to the current average current intensity, and the target brightness (for a single channel sub-pixel) corresponding to the target average current intensity.

Optionally, the first linear relationship is constructed based on the maximum brightness, minimum brightness, maximum load, and minimum load corresponding to the gray levels of each channel of the pixel unit; the maximum brightness is determined based on the relationship curve between gray level and brightness under maximum load, and the minimum brightness is determined based on the relationship curve between gray level and brightness under minimum load.

As shown in Figure 7, this embodiment provides a schematic diagram of a first linear relationship. Based on the maximum and minimum brightness corresponding to the grayscale of each channel, the minimum average current intensity corresponding to the maximum brightness, and the maximum average current intensity corresponding to the minimum brightness, a first linear relationship between the brightness and average current intensity of each channel is constructed.

In practice, for any RGB grayscale ( _k0 , _k1 , _k2 ) of an input image, the average current intensity corresponding to each channel grayscale per pixel of the input image is denoted as is, and the actual brightness corresponding to this grayscale is between the minimum brightness. and maximum brightness The relationship between the actual brightness and the average current intensity is linearly related to the minimum brightness. Therefore, a relationship between the actual brightness and the average current intensity is and the minimum brightness can be established through linear interpolation. Maximum brightness Based on the relationship between the values, the current brightness corresponding to each gray level _kc of each channel in each pixel unit is derived and calculated, as shown in the following formula:

In formula (5), This represents the current brightness of channel c, k represents the grayscale, c represents the channel, and is represents the current average current intensity. This represents the minimum brightness of channel c at grayscale k. This represents the maximum brightness of channel c at grayscale k.

Similarly, after determining the target average current intensity is', the target brightness... It can be determined using the following formula:

In formula (6), Let k represent the target brightness of channel c, k represent the grayscale, c represent the channel, and is′ represent the target average current intensity. This represents the minimum brightness of channel c at grayscale k. This represents the maximum brightness of channel c at grayscale k.

In some embodiments, the processor of this embodiment is specifically configured to determine each channel in the following manner. The first linear relationship between brightness and current intensity corresponding to the channel:

a) Based on the relationship curve between grayscale and brightness under maximum load, determine the maximum brightness corresponding to each channel grayscale of the pixel unit under maximum load; and based on the relationship curve between grayscale and brightness under minimum load, determine the minimum brightness corresponding to each channel grayscale of the pixel unit under minimum load.

Optionally, in this embodiment, the maximum load can be represented by the maximum current intensity, and the minimum load can be represented by the minimum current intensity. For ease of explanation, the relationship curve between grayscale and brightness under the maximum load is named the first relationship curve, and the relationship curve between grayscale and brightness under the minimum load is named the second relationship curve. It should be noted that the first relationship curve represents the relationship curve between grayscale and minimum brightness of each channel under the maximum current intensity; the second relationship curve represents the relationship curve between grayscale and maximum brightness of each channel under the minimum current intensity.

In implementation, the minimum brightness corresponding to each channel grayscale of the current image is determined according to the first relationship curve; the maximum brightness corresponding to each channel grayscale of the current image is determined according to the second relationship curve. Based on the relationship curves between grayscale and brightness under different current intensities, the minimum brightness corresponding to each channel grayscale under the maximum current intensity, and the maximum brightness corresponding to each channel grayscale under the minimum current intensity, can be determined.

In some embodiments, the processor of this embodiment is specifically configured to determine the relationship curve between grayscale and brightness under maximum or minimum load in the following manner:

a1) Determine the third test image, which includes grayscale images of each channel, and each channel grayscale image includes a preset area and a non-preset area; by setting the non-preset area in the third test image to white, changing the size and grayscale of the preset area in each channel grayscale image, and by setting the non-preset area in the third test image to black, changing the size and grayscale of the preset area in each channel grayscale image, determine the relationship between the load, grayscale and brightness of each channel;

Optionally, the preset area and the background area have different colors. The grayscale of the preset area varies from 0.1 to 1, for example, the grayscale of the preset area varies as follows: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1. This grayscale variation is only an example, and this embodiment does not impose excessive limitations on it. The background area includes white and black colors.

In some examples, the background color can be kept constant initially, and the brightness and average current intensity of the preset area can be measured by changing the size and grayscale of the preset area, thereby obtaining the value of each pass. The relationship between the average current intensity, grayscale, and brightness of each channel is obtained by changing the color of the background area and keeping it constant, and then measuring the brightness and average current intensity of the preset area by changing the size and grayscale of the preset area.

In practice, to achieve uniform brightness on the screen, it is necessary to find the current actual brightness and the target brightness to be achieved for any RGB input, and then adjust the grayscale value of the input to achieve voltage drop compensation.

a2) Based on the relationship between load, grayscale and brightness of each channel, fit the curves of grayscale and brightness of each channel under the maximum or minimum load.

In practice, to obtain the relationship between current intensity, grayscale, and brightness, as shown in Figure 8, this embodiment provides a schematic diagram of a third test image. The third test image includes an R-channel grayscale image group, a G-channel grayscale image group, and a B-channel grayscale image group. The third test image includes a preset area and a background area other than the preset area. The background area of each channel's grayscale image group is either white or black. By changing the size and grayscale of the preset area, the relationship between grayscale, current intensity, and brightness is obtained. For example, by fixing the background area to white, adjusting the grayscale values of the preset areas in each channel's grayscale image of the third test image, which contains preset areas of the same size, a set of grayscale images for each channel is obtained. Against a white background, the preset areas can be adjusted to change in ascending order; against a black background, the preset areas can be adjusted to change in descending order.

Using the third test image in this embodiment, the grayscale levels of the RGB three channels are traversed. By changing the area of the grayscale level on the screen and the background color, the brightness value at the center of the preset area where the grayscale level is located is measured, thus obtaining the current intensity-grayscale-brightness relationship for each of the RGB three channels. By fitting the current intensity and brightness relationship of each grayscale level, the brightness of each grayscale level at the maximum average current intensity (is = 1) can be obtained. Where k represents the gray level and c represents the channel. The brightness of each gray level at the minimum average current intensity (is = 0) can also be obtained.

During implementation, grayscale and brightness exhibit a non-linear relationship, with brightness changing exponentially with grayscale. Exponential fitting was used to obtain the grayscale k and minimum brightness for each channel under maximum current intensity. The first relationship curve is shown in Figure 9. This embodiment also provides a schematic diagram of the first relationship curve between gray levels and minimum brightness for each channel. The fitted first relationship curve between gray levels and minimum brightness is shown in Figure 9. Where k represents the gray level. This represents the minimum brightness of channel c at gray level k. Based on the relationship curves between different gray levels and minimum brightness, the exponent in the first relationship curve is obtained. Similarly, the grayscale k and maximum brightness of each channel under minimum current intensity can be obtained through exponential fitting. The second relationship curve, i.e., the second relationship curve between grayscale and brightness obtained by fitting. Where k represents the gray level. This represents the maximum brightness of channel c at grayscale k. Based on the relationship curves between different grayscale levels and maximum brightness, the exponent in the second relationship curve is obtained.

It should be noted that during image capture, the brightness data of the external environment is sampled and stored. However, the amount of brightness data is too large, and hardware resources are limited. To represent the vast range of brightness in nature with limited data, more information is needed to represent the dark areas that the human eye is sensitive to, and less data is needed to represent the less sensitive bright areas. Mapping the brightness data to grayscale values according to certain rules can compress the data volume while retaining more detail in the dark areas and sacrificing some detail in the bright areas. This conversion from brightness data to grayscale data is called inverse Gamma. When the image needs to be displayed on the screen, the display performs a forward Gamma transformation on the hardware, converting the grayscale values into brightness values and displaying them on the screen to form a pattern, restoring the brightness seen when the image was captured. While there is a loss of precision in this brightness transformation, the visual characteristics are lossless for the human eye. Therefore, this embodiment derives an exponential function based on the relationship curve between grayscale and brightness. and

Thus, for any input RGB image, based on the first relationship curve between grayscale and brightness of each channel under maximum current intensity, and the second relationship curve between grayscale and brightness of each channel under minimum current intensity, the maximum brightness corresponding to each channel grayscale of the input image can be calculated. and minimum brightness

b) Based on the maximum brightness, minimum brightness, maximum load, and minimum load corresponding to each channel gray level of the pixel unit, construct the first linear relationship between brightness and load under different gray levels.

In practice, normalization is performed to facilitate calculations, setting the minimum average current intensity at maximum brightness to 0 and the maximum average current intensity at minimum brightness to 1.

Step b3: Based on the non-linear relationship between brightness and grayscale, determine the grayscale of each channel of the pixel unit. Based on the current brightness and the target brightness, determine the compensation coefficients for the grayscale of each channel of the pixel unit.

In some embodiments, the processor of this embodiment is specifically configured to determine the compensation coefficients for each channel grayscale level in the following manner:

The compensation coefficient for each channel grayscale is determined based on the ratio of the current brightness to the target brightness corresponding to each channel grayscale of the pixel unit, wherein the compensation coefficient changes exponentially with the change of the ratio.

In implementation, the brightness of each of the RGB three channels is emitted by its respective grayscale, and there is a non-linear exponential gamma relationship between brightness and grayscale. Therefore, the current brightness corresponding to each channel grayscale ( _k0 , _k1 , _k2 ) of the input pixel unit needs to be adjusted to obtain the target brightness. The grayscale can be adjusted according to the ratio of brightness. Specifically, the compensation coefficient is determined by the following formula:

In formula (7), This represents the current brightness of channel c per pixel. k_c represents the target brightness per pixel unit channel c, k_{_c} represents the grayscale value per pixel unit of the current image, and k′_{_c} represents the adjusted grayscale value per pixel unit. Here, is represents the compensation coefficient for channel c per pixel, where is represents the current average current intensity per pixel, and is′ represents the target average current intensity per pixel. This represents the minimum brightness corresponding to grayscale k. This represents the maximum brightness corresponding to grayscale k. gamma _c is between... and A value between these two values can be linearly interpolated based on is.

Step c: Adjust the compensation coefficients of the grayscale of each channel of the pixel unit using the brightness parameters to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

In some embodiments, the brightness parameter in this embodiment includes a first brightness correction parameter; the first brightness correction parameter is determined based on the linear variation law of the highest brightness of the white image under different maximum brightness levels; the linear variation law of the highest brightness of the white image is determined based on the linear relationship between the highest brightness of the white image under the highest brightness that the display screen can display and the compensation coefficient.

The first brightness correction parameter is determined as follows:

Based on the linear relationship between the maximum brightness and compensation coefficient of solid color images under different DBVs, the linear variation law of the maximum brightness of solid color images under different DBVs is determined; according to the solid color images under different DBVs... The linear variation law of the highest brightness is used to determine the first brightness correction parameter under the DBV corresponding to the display screen.

Optionally, the solid color image in this embodiment includes, but is not limited to, a pure white image with a grayscale of 255. If there are other color images whose maximum brightness and compensation coefficient are also linearly related, then the solid color image in this embodiment also includes the other color image.

In implementation, the bandwidth high brightness (DBV) acts as a valve to adjust the maximum brightness of the screen. The maximum brightness setting of the OLED screen is achieved by adjusting the DBV value. Therefore, DBV is a variable parameter. To achieve the voltage drop compensation algorithm's adaptability to different DBV values, this embodiment of the invention experimentally summarizes the compensation coefficients under different DBV values. It was found that there is a linear relationship between the compensation coefficients under different DBV values and the maximum brightness of the pure white image under those DBV values, as shown in Figure 10. This embodiment provides a schematic diagram of the linear relationship between the compensation coefficient and the maximum brightness, including an R-channel grayscale image, a G-channel grayscale image, a B-channel grayscale image, and a C1 grayscale image. The grayscale values of the R-channel, G-channel, and B-channel of the C1 grayscale image are 115, 82, and 68, respectively. The corresponding relationships between the maximum brightness and the grayscale values of each channel under different DBV values for these four image modes are shown in the following table:

Table 1. Mapping table of compensation coefficients and maximum brightness under different DBVs.

By arbitrarily selecting the four image modes mentioned above, their compensation coefficients under different DBVs were calculated, and the brightness values corresponding to the full-screen pure white 255 grayscale under different DBVs were recorded. The rule of the compensation coefficient changing with brightness was obtained by fitting, and based on the rule, the compensation coefficient and white brightness in this embodiment were obtained. The degree values show an approximately linear relationship, but the linear relationship between the compensation coefficient and white brightness varies greatly for different image modes.

In some embodiments, the first brightness correction parameter includes a first scaling parameter and a first bias parameter. The first scaling parameter is determined based on the scaling degree of the change in the highest brightness of the white image under different maximum brightness levels; and/or, the first bias parameter is determined based on the bias degree of the change in the highest brightness of the white image under different maximum brightness levels.

Optionally, the first scaling parameter corresponding to different DBVs can be determined based on the scaling degree of the highest brightness change of the solid color image under different DBVs.

Optionally, the first bias parameter corresponding to different DBVs can be determined based on the bias degree of the highest brightness change of the solid color image under different DBVs.

In practice, to obtain the first brightness correction parameters for different DBVs of the display screen, the screen should be tested based on the initial DBV to obtain the first brightness correction parameters corresponding to the current DBV. Then, the current DBV should be adjusted to obtain the first brightness correction parameters corresponding to different DBVs. As shown below, this embodiment provides a LUT (Look-Up Table) schematic table of the first brightness correction parameters corresponding to DBV.

Table 2 DBV Luminous Parameter LUT

To facilitate recording and processing, this embodiment of the invention uses a one-dimensional lookup table (LUT) to record and save the first brightness correction parameters corresponding to DBV, as shown in Table 2. By default, DBV has 10 segments, and the pure white brightness Y corresponding to each DBV is obtained from actual measurement. The initial DBV used for the selected test screen parameters is generally the largest DBV value. The first brightness correction parameters for other DBVs are multiplied by a scaling parameter and then superimposed with an offset parameter, as shown in the following formula. The calculated compensation adjustment coefficients, after DBV adjustment, are shown below:

In formula (8), _a1 represents the first scaling parameter, and _b1 represents the first bias parameter. This represents the compensation coefficient calculated using compensation parameters, where c represents the channel, k represents the grayscale, is represents the current average current intensity, and is′ represents the target average current intensity. This represents the minimum brightness corresponding to grayscale k. This represents the maximum brightness corresponding to grayscale k. gamma _c is between... and A value between these two values can be linearly interpolated based on is.

In some embodiments, the brightness parameter in this embodiment includes a second brightness correction parameter; the second brightness correction parameter is determined based on the variation law of the compensation coefficient under different loads in n sub-linear relationships; the n sub-linear relationships are obtained by linear interpolation between the maximum compensation coefficient and the minimum compensation coefficient based on the linear relationship between the load and the compensation coefficient in high brightness mode, where n is an integer greater than 1.

Optionally, the second brightness correction parameter includes a second scaling parameter and a second bias parameter; the second scaling parameter is a scaling factor applied to each sub-linear relationship based on the variation of the compensation coefficient under different loads. The degree of bias is determined; and/or, the second bias parameter is determined for each sub-linear relationship based on the degree of bias of the compensation coefficient variation under different loads.

The second brightness correction parameter is determined as follows:

1) In HBM mode, based on the linear relationship between load and compensation coefficient, linear interpolation is performed between the maximum and minimum compensation coefficients to obtain n sub-linear relationships between load and compensation coefficient, where n is an integer greater than 1; the load is determined according to the image displayed on the screen.

In practice, the load OPR corresponding to the maximum compensation coefficient is 0. It should be noted that in this embodiment, when performing calculations of linear relationships, correspondence relationships or other algorithms, parameters such as load size, gray level, and average current intensity are usually normalized and processed into parameters between 0 and 1.

Optionally, this embodiment can insert one or more interpolations between the maximum and minimum compensation coefficients to obtain multiple sub-linear relationships between load and compensation coefficients. As shown in Figure 11, this embodiment provides a schematic diagram of the relationship between load and compensation coefficients in HBM mode. The effect of HBM mode is to achieve different compensation adjustment degrees based on different OPRs. Taking one interpolation as an example, interpolation can be performed in segments according to the user-set thresholds T1-Y1 and T2-Y2, where T1 and T2 represent the load, and Y1 and Y2 represent the compensation coefficients, resulting in three sub-linear relationships. The second brightness correction parameter is calculated based on each sub-linear relationship, and the relationship between the second brightness correction parameter and OPR is stored in a one-dimensional lookup table (LUT), which facilitates the display device to look up the corresponding second brightness correction parameter based on the load when adjusting the compensation coefficient.

1a) Optionally, the minimum compensation coefficient represents the compensation coefficient of the current image.

In practice, the compensation coefficients of each channel grayscale of the current image are first determined using the compensation parameters of the display screen. When the display screen is in HDM mode, the compensation coefficients can be further adjusted using the second brightness correction parameter to obtain the compensation adjustment coefficients corresponding to each channel. The compensation adjustment coefficients corresponding to each channel are then used to compensate the grayscale of each channel of the current image, and the compensated current image is displayed.

1b) Optionally, the brightness parameters include m, and the minimum compensation coefficient represents the compensation adjustment coefficient obtained by adjusting the compensation coefficient of the current image using at least one of the m-1 brightness parameters, where m is an integer greater than 1.

In implementation, if the brightness parameters include a first brightness correction parameter and a second brightness correction parameter; firstly After determining the compensation coefficients for each channel of the current image using the compensation parameters of the display screen, the corresponding first brightness correction parameter is determined based on the DBV of the display screen. The compensation coefficients are then adjusted using the first brightness correction parameter to obtain the first compensation adjustment coefficient. Finally, when the display screen is in HDM mode, the first compensation adjustment coefficient can be further adjusted using the second brightness correction parameter to obtain the compensation adjustment coefficients for each channel. The gray levels of each channel of the current image are then compensated using the compensation adjustment coefficients for each channel, and the compensated current image is displayed.

In implementation, if the brightness parameters include a first brightness correction parameter, a second brightness correction parameter, and a third brightness parameter, the following steps are taken: First, the compensation coefficients for each channel's grayscale of the current image are determined using the display screen's compensation parameters. Then, the first brightness correction parameter is used to adjust these coefficients to obtain a first compensation adjustment coefficient. Next, the second brightness correction parameter is used to adjust these coefficients to obtain a second compensation adjustment coefficient. Finally, the third brightness parameter is used to further adjust these coefficients, resulting in the compensation adjustment coefficients for each channel. These channel-specific compensation adjustment coefficients are then used to compensate for the grayscale of each channel of the current image, and the compensated image is displayed. When the brightness parameters include a first brightness correction parameter, a second brightness correction parameter, a third brightness parameter, and a fourth brightness parameter, the same adjustments are made sequentially to obtain the final compensation adjustment coefficients.

2) Based on the variation law of the compensation coefficient under different loads in the n sub-linear relationships, determine the second brightness correction parameter corresponding to the current image being displayed.

In some embodiments, the compensation coefficients in the n sub-linear relationships vary to different degrees with load changes; in the sub-linear relationships where the load is lower than the reference load, the compensation coefficient increases as the load decreases; in the sub-linear relationships where the load is higher than or equal to the reference load, the compensation coefficient is the minimum compensation coefficient; wherein the reference load represents the load corresponding to the minimum compensation coefficient, and the reference load is between the maximum load and the minimum load.

In some embodiments, the second brightness correction parameter includes a second scaling parameter and a second bias parameter; the processor is specifically configured to determine the second brightness correction parameter by any one or more of the following methods:

Method a: For each sub-linear relationship, determine the second scaling parameter corresponding to different loads in each sub-linear relationship based on the scaling degree of the compensation coefficient change under different loads;

Method b: For each sub-linear relationship, determine the second bias parameter corresponding to different loads in each sub-linear relationship based on the bias degree of the change in the compensation coefficient under different loads.

Taking an interpolation as an example, based on the linear relationship between different OPRs and compensation coefficients shown in Figure 11, the second brightness correction parameter includes a second scaling parameter and a second bias parameter. The relationship table of the second brightness coefficients corresponding to different OPRs is as follows:

Table 3 Second Luminance Correction Parameters under HBM Mode

Generally, the maximum compensation coefficient Y0 = 1, and the minimum compensation coefficient Y2 can be the compensation coefficient of the current image, or a compensation adjustment coefficient obtained by adjusting the compensation coefficient of the current image using at least one of the m-1 brightness parameters. Y1 is an interpolation value between Y0 and Y2. The interpolation calculation formula is shown below:
Y1＝(1-t)*Y2+t formula (9);

In formula (9), Y1 represents the interpolation compensation coefficient, Y2 represents the minimum compensation coefficient, and t takes the value of... The value is 0-1, which can be set by the user, for example, t=0.5.

Substituting Y0 = 1 and Y1 = (1-t)*Y2 + t into Table 3, we obtain the second luminance correction parameters based on Y2, as shown in the table below for the second luminance correction parameters in HBM mode:

Table 4 LUT Table of Second Luminance Correction Parameters in HBM Mode

In practice, when the minimum compensation coefficient represents the compensation coefficient of the current image, the compensation coefficients of each channel grayscale of the current image are first determined using the compensation parameters of the display screen. Then, the compensation coefficients are further adjusted using the second brightness correction parameter to obtain the compensation adjustment coefficients corresponding to each channel. The specific formula is as follows:

In formula (10), _a2 represents the second scaling parameter, and _b2 represents the second bias parameter. This represents the compensation coefficient calculated using compensation parameters, where c represents the channel, k represents the grayscale, is represents the current average current intensity, and is′ represents the target average current intensity. This represents the minimum brightness corresponding to grayscale k. This represents the maximum brightness corresponding to grayscale k. gamma _c is between and A value between these two values can be linearly interpolated based on is.

In implementation, when the brightness parameters include a first brightness correction parameter and a second brightness correction parameter, the minimum compensation coefficient represents the compensation adjustment coefficient obtained by adjusting the compensation coefficient of the current image using at least one of the m-1 brightness parameters. First, the compensation coefficients of each channel grayscale of the current image are determined using the compensation parameters of the display screen. Then, the first compensation adjustment coefficient is obtained by adjusting the compensation coefficient using the first brightness correction parameter. Finally, the first compensation adjustment coefficient is adjusted using the second brightness correction parameter to obtain the compensation adjustment coefficient corresponding to each channel. The specific formula is as follows:

In formula (11), _a1 represents the first scaling parameter, _b1 represents the first bias parameter, _a2 represents the second scaling parameter, and _b2 represents the second bias parameter. This represents the compensation coefficient calculated using compensation parameters, where c represents the channel, k represents the grayscale, is represents the current average current intensity, and is′ represents the target average current intensity. This represents the minimum brightness corresponding to grayscale k. This represents the maximum brightness corresponding to grayscale k. gamma _c is between... and A value between these two values can be linearly interpolated based on is.

It's important to note that HBM (Global High Brightness) is a high-brightness mode for OLED screens. While typical mobile phone screens reach a maximum brightness of 500 nits, HBM mode can achieve 800 nits or even 1000 nits. Enabling HBM in optical fingerprint recognition scenarios can improve fingerprint recognition success rates. However, excessive brightness can be glaring for users, so a mask (a solid color layer, using varying transparency to change screen brightness) needs to be added to the non-fingerprint area to reduce overall brightness. If the non-fingerprint area is black, no mask is needed.

In implementation, when the display is in HBM mode, such as in fingerprint unlocking scenarios, there is a linear relationship between the display load and the compensation coefficient. By setting one or more interpolations, compensation coefficients with different compensation levels corresponding to different load ranges can be obtained. Based on the linear relationship between the load and the compensation coefficient, the second brightness correction parameters corresponding to different load areas can be obtained. When the display is in HBM mode, adjusting the compensation coefficient using the second brightness correction parameters can yield a suitable compensation coefficient for the current load. The appropriate level of compensation.

It should be noted that the load (OPR, On Pixel Ratio) in this embodiment is determined based on the image displayed on the screen. Optionally, the load can be adjusted by fixing the grayscale and changing the area of the test image displayed on the screen. By inputting the test image to the screen and adjusting the area of the test image, different load sizes can be obtained, thereby achieving different levels of brightness compensation based on different loads.

Step d: Use the compensation adjustment coefficients of the gray levels of each channel of the pixel unit to compensate the gray levels of each channel of the pixel unit, and display the compensated current image.

In some embodiments, the brightness parameter includes a scaling parameter and an offset parameter, and the processor is specifically configured to determine the compensation adjustment coefficient in the following manner:

The compensation adjustment coefficient is obtained by linearly adjusting the compensation coefficient using scaling and bias parameters.

Optionally, the brightness parameters include m parameters, and the processor is specifically configured to execute:

The compensation coefficient of the current image is linearly adjusted using the first brightness parameter to obtain the first brightness adjustment coefficient. When linearly adjusting the compensation coefficient of the current image using the first brightness parameter, the compensation coefficient is scaled using the scaling parameter of the first brightness parameter and biased using the offset parameter of the first brightness parameter to obtain the first brightness adjustment coefficient.

The first brightness adjustment coefficient is linearly adjusted using the second brightness parameter to obtain the second brightness adjustment coefficient; and so on, the (m-1)th brightness adjustment coefficient is linearly adjusted using the mth brightness parameter to obtain the mth brightness adjustment coefficient, and the mth brightness adjustment coefficient is determined as the final compensation adjustment coefficient.

In practice, after calculating the compensation adjustment coefficient, if the compensation adjustment coefficient is the coefficient of the above formula (11), then the gray levels of each channel of the current image are compensated using the following formula:

In formula (12), k_{_c} represents the gray level of the current image channel c, and k′_{_c} represents the gray level of the current image channel c after compensation; a _₁ represents the first scaling parameter, b_₁ represents the first bias parameter, a _₂ represents the second scaling parameter, and b_₂ represents the second bias parameter. Indicates the use of compensation parameters The compensation coefficient is calculated from the data, where c represents the channel, k represents the grayscale, is represents the current average current intensity, and is′ represents the target average current intensity. This represents the minimum brightness corresponding to grayscale k. This represents the maximum brightness corresponding to grayscale k. gamma _c is between... and A value between these two values can be linearly interpolated based on is.

This embodiment addresses the automated adjustment and deployment of IP (Intellectual Property) to address voltage drop issues in OLED screen circuitry. Based on screen characteristics and customer needs, IP interface parameters, such as compensation and brightness parameters, can be modified. This achieves circuit voltage drop compensation while simultaneously adjusting parameters under different bandwidth high-brightness DBV (display brightness values), and updating parameters for switching between normal and high-brightness compensation modes.

As shown in Figure 12, this embodiment provides a schematic diagram of the compensation effect. As can be seen from the figure, in the absence of voltage drop compensation mode, the brightness of white 255 decreases as the illuminated area (OPR) increases. In the voltage drop compensation mode (i.e., the compensation mode using a compensation coefficient determined by compensation parameters), the brightness of white 255 does not change with OPR, maintaining brightness consistency. In the high-brightness compensation mode (i.e., the compensation adjustment coefficient determined by compensation parameters and brightness parameters), based on the user-defined compensation inflection point (i.e., interpolation), different compensation levels are achieved for different OPRs, realizing a correspondence between brightness and OPR. The high-brightness mode is mainly used for localized brightening, such as the fingerprint unlocking area and menu area.

This invention also proposes an adjustable OLED voltage drop automatic compensation system. Addressing the characteristic differences among various OLED screens, this embodiment proposes a device that automatically updates the algorithm IP (Intellectual Property) based on screen characteristics, achieving adjustable voltage drop compensation. The system proposed in this embodiment includes software system implementation, hardware system implementation, algorithm IP design, and algorithm IP update method design. It solves the brightness difference caused by screen voltage drop. Simultaneously, it can dynamically update parameters based on the screen's DBV characteristics and high-brightness mode characteristics. This system can facilitate screen mass production upgrades and improve production efficiency.

This invention proposes an adjustable OLED voltage drop automatic compensation system, including but not limited to system architecture implementation, compensation algorithm design and implementation, IP RTL (Register Transfer Level) architecture, and software logic for IP updates. The system architecture comprises hardware and software components. This includes the deployment and workflow of different software and hardware.

As shown in Figure 13, this embodiment provides an automatic compensation system, including an OLED screen, a control computer, a precision measurement PG, and optical acquisition instruments. The OLED screen is equipped with a display driver chip IC (Integrated Circuit), used to control the display driver circuit and drive the screen pixels to emit light. The control system and compensation algorithm IP related to the screen display are deployed in the driver IC. The precision measurement PG (pattern generation) is a dot pattern fixture used to generate the test image required for the test screen and send the image or video signal to the driver IC through image and video transmission protocols such as MIPI (Mobile Industry Processor Interface), eDP (Embedded DisplayPort), and LVDS (Low Voltage Differential Signaling). On the other hand, the system receives instructions and parameters from the control software and updates the compensation algorithm IP built into the IC through the I2C (IIC, Inter-Integrated Circuit) or SPI (Serial Peripheral Interface) protocols. Specifically, the compensation and brightness parameters built into the IC are updated. Since voltage drop in the OLED circuit primarily causes screen brightness non-uniformity, this embodiment uses an optical acquisition instrument, such as the CA410 brightness acquisition device, to capture the relationship between brightness and display load. This instrument can automatically acquire brightness at different locations on the screen according to instructions from the control system, and then return information such as brightness and color coordinates for subsequent analysis and modeling. The control computer (PC) is equipped with optical acquisition instrument control software, algorithm IP control software, and image signal generator control software, providing users with adjustment interfaces to achieve screen adjustment needs such as parameter setting (compensation and brightness parameters), parameter update control (compensation and brightness parameters), and IP deployment.

As shown in Figure 14, this embodiment also provides a schematic diagram of the compensation algorithm design. For each RGB sub-pixel in the input image, the current average current intensity corresponding to each sub-pixel is calculated. The first linear relationship between brightness and current intensity is stored in a LUT table. The current brightness corresponding to the current average current intensity of each sub-pixel is looked up, and the target brightness corresponding to the target average current intensity of the maximum grayscale value is determined based on the maximum grayscale value in the RGB sub-pixel. The compensation coefficient is calculated based on the current brightness and target brightness of each sub-pixel to obtain the compensation coefficients for each of the three RGB channels. The compensation coefficients are adjusted based on the first brightness correction parameter corresponding to DBV and/or the second brightness correction parameter under HBM mode to obtain... The compensation adjustment coefficient is used to compensate the grayscale value of each sub-pixel, and the final compensated image is output.

In this embodiment of the invention, when implementing the compensation algorithm using compensation parameters and brightness parameters, the compensation algorithm is ultimately deployed on the driver chip. This embodiment uses RTL (Register-Transfer Level) design for the compensation algorithm IP, as shown in Figure 15. This embodiment provides a data flow diagram of the compensation algorithm IP, using a total of 15 LUTs to decompose the calculation of each node in the compensation algorithm flow. The compensation parameters or brightness parameters in the LUTs can be updated according to different screens. Specifically, LUTs 1-3 are used to calculate the current average current intensity *is* after combining the RGB three-channel input grayscale levels; LUT 4 is used to calculate the target average current intensity *is'*; LUTs 5-7 are used to calculate the ratio of the maximum brightness to the minimum brightness of each of the RGB three-channel input grayscale levels; LUTs 8-13 are used to calculate the compensation coefficients; LUT 14 stores the first scaling parameter and the first bias parameter corresponding to DBV; and LUT 15 stores the second scaling parameter and the second bias parameter corresponding to HBM mode.

As shown in Figure 16, in order to achieve the adjustability of the compensation parameters and brightness parameters involved in the compensation algorithm IP, this embodiment of the invention also provides a hardware and software deployment process for updating the compensation parameters and brightness parameters. First, the brightness of the current image displayed on the OLED screen is optically measured by the host computer, and the measured optical data information is transmitted to an external system for processing (such as a PC). The compensation parameters and brightness parameters are updated using the optical data information, and the updated compensation parameters and brightness parameters are stored in an external memory. The driver chip of the display device reads the compensation parameters and brightness parameters from the external memory, compensates the current image, obtains the compensated image information, and sends it to the OLED screen for display.

As shown in Figure 17, this embodiment provides a flowchart for updating compensation parameters and brightness parameters. After the display screen is turned on, it is determined whether the compensation parameters and brightness parameters are burned into the external memory. If so, the compensation parameters and brightness parameters are loaded into the driver chip, and the grayscale of the current image is compensated using the compensation parameters and brightness parameters, and the compensated current image is displayed. Otherwise, the host computer is notified to start the precision measurement PG for image display, control the optical acquisition instrument to collect optical data, calculate the compensation parameters and brightness parameters based on the collected optical data, and burn the compensation parameters and brightness parameters into the external memory. Thus, for real-time input images, voltage drop compensation is achieved using the compensation parameters and brightness parameters based on the compensation algorithm. Real-time voltage drop compensation and display of the compensated image.

As shown in Figure 18, this embodiment also provides a voltage drop compensation method in high brightness mode, and the specific implementation process is as follows:

Step 1800: Obtain the display screen compensation parameters, first brightness correction parameters, and second brightness correction parameters from the driver chip;

Step 1801: Based on the compensation parameters, estimate the input load and maximum load of the pixel unit in the current image;

Step 1802: Based on the first linear relationship between brightness and load at different gray levels, determine the current brightness of each channel gray level of the pixel unit under the input load and the target brightness under the maximum load by using linear interpolation.

Step 1803: Based on the nonlinear relationship between brightness and grayscale, determine the compensation coefficient of grayscale for each channel of the pixel unit according to the current brightness and target brightness corresponding to each channel grayscale of the pixel unit.

Step 1804: Linearly adjust the compensation coefficients of each channel grayscale of the pixel unit using the first brightness correction parameter to obtain the first compensation adjustment coefficients of each channel grayscale of the pixel unit.

Step 1805: Linearly adjust the first compensation adjustment coefficient of each channel grayscale of the pixel unit using the second brightness correction parameter to obtain the compensation adjustment coefficient of each channel grayscale of the pixel unit.

Optionally, the compensation coefficients of the grayscale of each channel of the pixel unit are first linearly adjusted using the second brightness correction parameter to obtain the second compensation adjustment coefficients of the grayscale of each channel of the pixel unit; then, the second compensation adjustment coefficients of the grayscale of each channel of the pixel unit are linearly adjusted using the first brightness correction parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

Step 1806: Using the compensation adjustment coefficients of the gray levels of each channel of the pixel unit, compensate the gray levels of each channel of the pixel unit, and display the compensated current image.

This embodiment improves the display characteristics of OLED screens and increases mass production efficiency by automatically testing and updating compensation and brightness parameters for different displays. The provided compensation algorithm estimates and compensates in real time based on image content and can adapt to screen characteristics. It solves the brightness difference caused by voltage drop. At the same time, it can dynamically update parameters based on the screen's DBV characteristics and high brightness mode characteristics. Based on the screen's characteristics, it can effectively improve the compensation effect.

Based on the same inventive concept, this disclosure also provides a display device, as shown in FIG19, including a display screen 1900 and a control circuit 1901:

The display screen 1900 is configured to display content;

The control circuit 1901 includes a processor and a memory. The processor is used to read a program from the memory and execute the following steps:

Acquire the current image and determine the input load on the display screen when the current image is displayed;

Based on the sub-linear relationship corresponding to the input load among n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load;

The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1.

As an optional implementation, the degree of change of the compensated brightness with load variation in the n sub-linear relationships is different; in the sub-linear relationship where the load is lower than the reference load, the compensation coefficient increases as the load decreases; in the sub-linear relationship where the load is higher than or equal to the reference load, the compensation coefficient is the minimum compensation coefficient; wherein the reference load represents the load corresponding to the minimum compensated brightness, and the reference load is between the maximum load and the minimum load.

As an optional implementation, the processor is specifically configured to execute:

Obtain the compensation coefficients for each channel grayscale of at least one pixel unit in the current image; determine n sub-linear relationships between load and compensation coefficients, where n is an integer greater than 1; adjust the compensation coefficients for each channel grayscale of the pixel unit according to the variation law of the compensation coefficients under different loads in the n sub-linear relationships, and obtain the compensation adjustment coefficients for each channel grayscale of the pixel unit.

As an optional implementation, the processor is specifically configured to execute:

Based on the variation law of the compensation coefficient under different loads in the n sub-linear relationships, determine the brightness parameters corresponding to different loads;

The compensation coefficients for each channel grayscale of the pixel unit are adjusted using the brightness parameters corresponding to different loads.

As an optional implementation, the brightness parameters include scaling parameters and offset parameters; the processor is specifically configured to execute:

For each sub-linear relationship, determine the scaling parameters corresponding to different loads within each sub-linear relationship based on the scaling degree of the compensation coefficient variation under different loads; and/or,

For each sub-linear relationship, the bias parameters corresponding to different loads in each sub-linear relationship are determined based on the degree of bias of the compensation coefficient change under different loads.

As an optional implementation, the minimum compensation coefficient represents the compensation coefficient for each channel grayscale of the pixel unit; or,

The brightness parameters include m parameters, and the minimum compensation coefficient represents the compensation adjustment coefficient obtained by adjusting the compensation coefficient of each channel grayscale of the pixel unit using at least one of the m-1 brightness parameters, where m is an integer greater than 1.

Based on the same inventive concept, this disclosure also provides a voltage drop compensation method. The principle of this method in solving the problem is similar to that of the display device. Therefore, the implementation of this method can be referred to the implementation of the display device, and repeated details will not be described again.

As shown in Figure 20, the implementation process of this voltage drop compensation method is as follows:

Step 2000: Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined according to the display characteristics of the display screen;

Step 2001: Determine the compensation coefficients for the grayscale of at least one pixel unit in each channel of the current image displayed on the screen according to the compensation parameters;

Step 2002: Adjust the compensation coefficients of the grayscale of each channel of the pixel unit using the brightness parameters to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

Step 2003: Using the compensation adjustment coefficients of the gray levels of each channel of the pixel unit, compensate the gray levels of each channel of the pixel unit, and display the compensated current image.

As an optional implementation, determining the compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen based on the compensation parameters includes:

Based on the compensation parameters, the input load and maximum load of the pixel unit in the current image are estimated, where the maximum load represents the input load of the grayscale image generated using the maximum value of each channel grayscale of the pixel unit.

Based on the first linear relationship between brightness and load at different gray levels, the current brightness of each channel gray level of the pixel unit under the input load and the target brightness under the maximum load are determined by linear interpolation.

Based on the nonlinear relationship between brightness and grayscale, the compensation coefficients for each channel grayscale of the pixel unit are determined according to the current brightness and target brightness corresponding to each channel grayscale of the pixel unit.

As an optional implementation, the compensation parameters include coefficient parameters for each channel; the coefficient parameters for each channel are determined as follows:

Determine the second linear relationship between brightness and load in a pure white image;

A first test image is determined, which includes grayscale images of each channel. Each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image.

Based on the second linear relationship, determine the load corresponding to the brightness of the preset area of the grayscale image of each channel in the first test image;

The coefficient parameters for each channel are determined based on the load corresponding to the preset area of the grayscale image of each channel in the first test image, and the proportion of the preset area to the display area of the grayscale image of each channel.

As an optional implementation, the compensation parameters include index parameters for each channel; the index parameters for each channel are determined as follows:

Determine the second linear relationship between brightness and load in a pure white image;

A second test image is determined, which includes grayscale images of each channel. Each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image.

Change the grayscale values of non-preset areas in each channel of the second test image to determine the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in each channel of the grayscale image.

Based on the second linear relationship and the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in each channel grayscale image, the load corresponding to the grayscale values of non-preset areas in each channel grayscale image is determined.

Based on the exponential change in load with grayscale, and according to the non-pre-load data in each channel's grayscale image... Define the load corresponding to the grayscale value of the region and determine the index parameters for each channel.

As an optional implementation, based on the exponential variation of load with grayscale, the exponential parameters for each channel are determined according to the load corresponding to the grayscale values of non-preset areas in the grayscale image of each channel, including:

Based on the load corresponding to the grayscale values of non-preset areas in the grayscale images of each channel, and the proportion of the preset area in the display area of each channel's grayscale images, the relationship curve between grayscale and load of each channel is fitted.

Based on the relationship curve between grayscale and load of each channel, the load variation law of grayscale of each channel is determined.

As an optional implementation, the first linear relationship between brightness and load at different gray levels is determined as follows:

Based on the relationship curve between grayscale and brightness under maximum load, determine the maximum brightness corresponding to each channel grayscale of the pixel unit under maximum load; and based on the relationship curve between grayscale and brightness under minimum load, determine the minimum brightness corresponding to each channel grayscale of the pixel unit under minimum load.

Based on the maximum brightness, minimum brightness, maximum load, and minimum load corresponding to each channel grayscale of the pixel unit, a first linear relationship between brightness and load under different grayscale levels is constructed.

As an optional implementation, the relationship curve between grayscale and brightness under maximum or minimum load is determined as follows:

A third test image is determined, which includes grayscale images of each channel, and each grayscale image of each channel includes a preset area and a non-preset area.

By setting the non-preset area in the third test image to white, changing the size and grayscale of the preset area in each channel's grayscale image, and setting the non-preset area in the third test image to black, changing the size and grayscale of the preset area in each channel's grayscale image, the relationship between the load, grayscale, and brightness of each channel is determined.

Based on the relationship between load, grayscale, and brightness of each channel, the relationship curves between grayscale and brightness of each channel under the maximum or minimum load are obtained by fitting.

As an optional implementation, the brightness parameters include a first brightness correction parameter; through The first brightness correction parameter is determined as follows:

Based on the linear relationship between the maximum brightness of the white image under the highest brightness that the display screen can display and the compensation coefficient, the linear variation law of the maximum brightness of the white image under different maximum brightness is determined.

Based on the linear variation law of the maximum brightness of the white image under different maximum brightness levels, the first brightness correction parameter under the maximum brightness of the display screen is determined.

As an optional implementation, the first brightness correction parameter includes a first scaling parameter and a first bias parameter; determining the first brightness correction parameter at the highest brightness of the display screen based on the linear variation law of the highest brightness of the white image under different maximum brightness levels includes:

Based on the scaling degree of the maximum brightness change of the white image under different maximum brightness levels, determine the first scaling parameter for different maximum brightness levels; and/or,

The first bias parameter for different maximum brightness levels is determined based on the degree of bias in the maximum brightness variation of the white image under different maximum brightness levels.

As an optional implementation, the brightness parameter includes a second brightness correction parameter; the second brightness correction parameter is determined in the following manner:

In high-brightness mode, based on the linear relationship between load and compensation coefficient, linear interpolation is performed between the maximum and minimum compensation coefficients to obtain n sub-linear relationships between load and compensation coefficient, where n is an integer greater than 1; the load is determined according to the image displayed on the screen.

Based on the variation law of the compensation coefficient under different loads in the n sub-linear relationships, the second brightness correction parameter corresponding to the displayed current image is determined.

As an optional implementation, the second brightness correction parameter includes a second scaling parameter and a second offset parameter; determining the second brightness correction parameter corresponding to the displayed current image based on the variation law of the compensation coefficients under different loads in the n sub-linear relationships includes:

For each sub-linear relationship, based on the scaling degree of the compensation coefficient variation under different loads, determine the second scaling parameter corresponding to different loads in each sub-linear relationship; and/or,

For each sub-linear relationship, the second bias parameter corresponding to different loads in each sub-linear relationship is determined based on the bias degree of the change in the compensation coefficient under different loads.

Based on the same inventive concept, this disclosure also provides a voltage drop compensation method, as shown in Figure 21. The specific implementation flow of this method is as follows:

Step 2100: Obtain the current image and determine the input load of the display screen when the current image is displayed;

Step 2101: Based on the sub-linear relationship corresponding to the input load among the n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load;

The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1.

Based on the same inventive concept, this disclosure also provides an electronic device that solves the problem in a similar principle to the display device. Therefore, the implementation of this electronic device can refer to the implementation of the display device, and repeated details will not be described again.

As shown in Figure 22, the electronic device includes a processor 2200 and a memory 2201. The memory 2201 is used to store programs executable by the processor 2200. The processor 2200 is used to read the programs in the memory 2201 and perform the following steps:

Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen;

The compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen are determined based on the compensation parameters.

The compensation coefficients of the grayscale of each channel of the pixel unit are adjusted using the brightness parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit.

The gray levels of each channel of the pixel unit are compensated using the compensation adjustment coefficients of each channel, and the compensated current image is then displayed.

Based on the same inventive concept, this disclosure also provides an electronic device that solves the problem in a similar principle to the display device. Therefore, the implementation of this electronic device can refer to the implementation of the display device, and repeated details will not be described again.

As shown in Figure 23, the electronic device includes a processor 2300 and a memory 2301, wherein the memory 2301 is used to store a program executable by the processor 2300, and the processor 2300 is used to read the program in the memory 2301 and perform the following steps:

Acquire the current image and determine the input load on the display screen when the current image is displayed;

Based on the sub-linear relationship corresponding to the input load among n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load;

The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1.

Based on the same inventive concept, this disclosure also provides a voltage drop compensation system, as shown in FIG24, including a control device 2400 and a display device 2401;

The control device 2400 is used to determine the compensation parameters and brightness parameters corresponding to the display screen of the display device, and write the compensation parameters and brightness parameters into the driver chip of the display device; wherein the compensation parameters and brightness parameters are determined according to the display characteristics of the display screen;

The display device 2401 is used to determine the compensation coefficient of each channel grayscale of at least one pixel unit in the current image displayed on the display screen according to the compensation parameters; adjust the compensation coefficient of each channel grayscale of the pixel unit using the brightness parameters to obtain the compensation adjustment coefficient of each channel grayscale of the pixel unit; compensate the grayscale of each channel of the pixel unit using the compensation adjustment coefficient of each channel grayscale of the pixel unit, and display the compensated current image.

Based on the same inventive concept, this disclosure also provides a voltage drop compensation device. The principle of this device in solving the problem is similar to that of the display device. Therefore, the implementation of this method can be referred to the implementation of the display device, and the repeated parts will not be described again.

As shown in Figure 25, the device includes:

The parameter acquisition module 2500 is used to acquire the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined according to the display characteristics of the display screen;

The coefficient determination module 2501 is used to determine the compensation coefficients of each channel grayscale of at least one pixel unit in the current image displayed on the display screen according to the compensation parameters.

The coefficient adjustment module 2502 is used to adjust the compensation coefficient of each channel grayscale of the pixel unit using the brightness parameter, so as to obtain the compensation adjustment coefficient of each channel grayscale of the pixel unit.

The image compensation module 2503 is used to compensate the gray levels of each channel of the pixel unit using the compensation adjustment coefficient of each channel gray level, and to display the compensated current image.

Based on the same inventive concept, this disclosure also provides a voltage drop compensation device. The principle of this device in solving the problem is similar to that of the display device. Therefore, the implementation of this method can be referred to the implementation of the display device, and the repeated parts will not be described again.

As shown in Figure 26, the device includes:

The load module 2600 is used to acquire the current image and determine the input load of the display screen when the current image is displayed.

The brightness compensation module 2601 is used to determine the compensation brightness corresponding to the input load based on the sub-linear relationship corresponding to the input load among n sub-linear relationships between the load and the compensation brightness; wherein the n sub-linear relationships are obtained by linear interpolation between the maximum compensation brightness and the minimum compensation brightness based on the linear relationship between the load and the compensation brightness, and n is an integer greater than 1.

Based on the same inventive concept, this disclosure provides a computer storage medium comprising: computer program code, which, when executed on a computer, causes the computer to perform any of the voltage drop compensation methods discussed above. Since the principle by which the computer storage medium solves the problem is similar to that of the voltage drop compensation method, the implementation of the computer storage medium can be referred to the implementation of the method, and repeated details will not be elaborated further.

In specific implementation, computer storage media can include: Universal Serial Bus Flash Drive (USB), portable hard drive, Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disk or optical disk, and other storage media that can store program code.

Based on the same inventive concept, this disclosure also provides a computer program product, which includes: computer program code, which, when executed on a computer... At this time, the computer executes any of the voltage drop compensation methods discussed above. Since the principle behind the problem-solving of the above computer program product is similar to that of the voltage drop compensation method, the implementation of the above computer program product can be found in the implementation of the method, and repeated details will not be elaborated here.

Computer program products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, systems, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

This disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more flowchart illustrations and/or one or more block diagrams.

These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction device that implements the functions specified in one or more flowcharts and/or one or more block diagrams.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and/or one or more block diagrams.

Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims (32)

A display device, comprising a display screen and control circuitry: The display screen is configured to display content; The control circuit includes a processor and a memory. The processor is used to read the program in the memory and execute the following steps: Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen; The compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen are determined based on the compensation parameters. The compensation coefficients of the grayscale of each channel of the pixel unit are adjusted using the brightness parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit. The gray levels of each channel of the pixel unit are compensated using the compensation adjustment coefficients of each channel, and the compensated current image is then displayed. The display device according to claim 1, wherein the processor is specifically configured to execute: Based on the compensation parameters, the input load and maximum load of the pixel unit in the current image are estimated, where the maximum load represents the input load of the grayscale image generated using the maximum value of each channel grayscale of the pixel unit. Based on the first linear relationship between brightness and load at different gray levels, the current brightness of each channel gray level of the pixel unit under the input load and the target brightness under the maximum load are determined by linear interpolation. Based on the nonlinear relationship between brightness and grayscale, the compensation coefficients for each channel grayscale of the pixel unit are determined according to the current brightness and target brightness corresponding to each channel grayscale of the pixel unit. The display device according to claim 1, wherein the compensation parameters include coefficient parameters for each channel and exponential parameters for each channel; the processor is specifically configured to execute: Based on the grayscale of each channel, the coefficient parameters of each channel, and the index of each channel in the current image. Numerical parameters are used to estimate the input load per pixel unit; or, The maximum load of the pixel unit is estimated by using the grayscale values of each channel of the grayscale image generated based on the maximum grayscale values of each channel of the pixel unit, the grayscale values of each channel, the coefficient parameters of each channel, and the exponent parameters of each channel; wherein the grayscale image represents an image with the same grayscale values in each channel. The display device according to claim 1, wherein the compensation parameters include coefficient parameters for each channel; The coefficient parameters of each channel are determined based on the load corresponding to the preset area of the grayscale image of each channel in the first test image, and the proportion of the preset area to the display area of the grayscale image of each channel; the load corresponding to the preset area is determined based on the second linear relationship between the brightness of the pure white image and the load. The first test image includes grayscale images of each channel, and each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image. The display device according to claim 1, wherein the compensation parameters include index parameters for each channel; The index parameters for each channel are determined based on the exponential change of load with grayscale, according to the load corresponding to the grayscale values of non-preset areas in the grayscale images of each channel. The load corresponding to the grayscale values of non-preset areas is determined based on the second linear relationship between the brightness and load of the pure white image, and the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in the grayscale images of each channel obtained by changing the grayscale values of non-preset areas in the grayscale images of each channel in the second test image. The second test image includes grayscale images of each channel. Each grayscale image includes a preset area and a non-preset area. The preset area is a pure white image, and the non-preset area is a non-pure white image. The display device according to claim 2, wherein, The first linear relationship is constructed based on the maximum brightness, minimum brightness, maximum load, and minimum load corresponding to the gray levels of each channel of the pixel unit; the maximum brightness is determined based on the relationship curve between gray level and brightness under maximum load, and the minimum brightness is determined based on the relationship curve between gray level and brightness under minimum load. The display device according to claim 6, wherein, The grayscale and brightness relationship curves under maximum or minimum load are based on the corresponding curves of each channel. The relationship between load, grayscale, and brightness is obtained by fitting the relationship between load, grayscale, and brightness for each channel. This relationship is obtained by setting the non-preset area in the third test image to white and changing the size and grayscale of the preset area in the grayscale image of each channel, and by setting the non-preset area in the third test image to black and changing the size and grayscale of the preset area in the grayscale image of each channel. The third test image includes grayscale images of each channel, and each channel grayscale image includes a preset area and a non-preset area. The display device according to claim 2, wherein the processor is specifically configured to execute: The compensation coefficient for each channel grayscale is determined based on the ratio of the current brightness to the target brightness corresponding to each channel grayscale of the pixel unit, wherein the compensation coefficient changes exponentially with the change of the ratio. The display device according to claim 1, wherein the brightness parameter includes a first brightness correction parameter; The first brightness correction parameter is determined based on the linear variation law of the highest brightness of the white image under different maximum brightness levels; the linear variation law of the highest brightness of the white image is determined based on the linear relationship between the highest brightness of the white image under the highest brightness that the display screen can display and the compensation coefficient. The display device according to claim 9, wherein the first brightness correction parameter includes a first scaling parameter and a first bias parameter; The first scaling parameter is determined based on the scaling degree of the maximum brightness variation of the white image under different maximum brightness levels; and/or, The first bias parameter is determined based on the degree of bias of the change in the maximum brightness of the white image under different maximum brightness levels. The display device according to claim 1, wherein the brightness parameter includes a second brightness correction parameter; The second brightness correction parameter is determined based on the variation law of the compensation coefficient under different loads in the n sub-linear relationships; the n sub-linear relationships are obtained by linear interpolation between the maximum compensation coefficient and the minimum compensation coefficient based on the linear relationship between the load and the compensation coefficient in the high brightness mode, where n is an integer greater than 1. The display device according to claim 11, wherein the second brightness correction parameter includes a second scaling parameter and a second offset parameter; The second scaling parameter is determined for each sub-linear relationship based on the scaling degree of the compensation coefficient variation under different loads; and/or, The second bias parameter is determined for each sub-linear relationship based on the degree of bias of the compensation coefficient variation under different loads. The display device according to claim 11, wherein, The minimum compensation coefficient represents the compensation coefficient of the current image; or, The brightness parameters include m parameters, and the minimum compensation coefficient represents the compensation adjustment coefficient obtained by adjusting the compensation coefficient of the current image using at least one of the m-1 brightness parameters, where m is an integer greater than 1. The display device according to claim 11, wherein the compensation coefficients in the n sub-linear relationships vary to different degrees with load changes; In the sublinear relationship where the load is lower than the reference load, the compensation coefficient increases as the load decreases; In sub-linear relationships where the load is higher than or equal to the reference load, the compensation coefficient is the minimum compensation coefficient; The reference load represents the load corresponding to the minimum compensation coefficient, and the reference load is between the maximum load and the minimum load. The display device according to claim 1, wherein the brightness parameter includes a scaling parameter and an offset parameter, and the processor is specifically configured to execute: The compensation adjustment coefficient is obtained by linearly adjusting the compensation coefficient using scaling and bias parameters. The display device according to claim 1, wherein the processor is specifically configured to execute: Obtain the display's compensation and brightness parameters from the driver chip; The compensation parameter is used to compensate for grayscale under different loads, and the brightness parameter is used to adjust the degree of grayscale compensation under different loads; different displays have different compensation parameters, and/or different displays have different brightness parameters. A display device, comprising a display screen and control circuitry: The display screen is configured to display content; The control circuit includes a processor and a memory. The processor is used to read the program in the memory and execute the following steps: Acquire the current image and determine the input load on the display screen when the current image is displayed; Based on the sub-linear relationship corresponding to the input load among n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load; The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1. The display device according to claim 17, wherein the degree of change of the compensated brightness in the n sub-linear relationships with load varies; In the sublinear relationship where the load is lower than the reference load, the compensation coefficient increases as the load decreases; In sub-linear relationships where the load is higher than or equal to the reference load, the compensation coefficient is the minimum compensation coefficient; The reference load represents the load corresponding to the minimum compensated brightness, and the reference load is between the maximum load and the minimum load. A voltage drop compensation method, wherein the method includes: Obtain the compensation parameters and brightness parameters of the display screen, wherein the compensation parameters and brightness parameters are determined based on the display characteristics of the display screen; The compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen are determined based on the compensation parameters. The compensation coefficients of the grayscale of each channel of the pixel unit are adjusted using the brightness parameter to obtain the compensation adjustment coefficients of the grayscale of each channel of the pixel unit. The gray levels of each channel of the pixel unit are compensated using the compensation adjustment coefficients of each channel, and the compensated current image is then displayed. According to the method of claim 19, wherein determining the compensation coefficients for each channel grayscale of at least one pixel unit in the current image displayed on the screen based on the compensation parameters comprises: Based on the compensation parameters, the input load and maximum load of the pixel unit in the current image are estimated, where the maximum load represents the grayscale generated using the maximum value of each channel grayscale of the pixel unit. Input load of the image; Based on the first linear relationship between brightness and load at different gray levels, the current brightness of each channel gray level of the pixel unit under the input load and the target brightness under the maximum load are determined by linear interpolation. Based on the nonlinear relationship between brightness and grayscale, the compensation coefficients for each channel grayscale of the pixel unit are determined according to the current brightness and target brightness corresponding to each channel grayscale of the pixel unit. According to the method of claim 19, the compensation parameters include channel coefficient parameters; the channel coefficient parameters are determined in the following manner: Determine the second linear relationship between brightness and load in a pure white image; A first test image is determined, which includes grayscale images of each channel. Each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image. Based on the second linear relationship, determine the load corresponding to the brightness of the preset area of the grayscale image of each channel in the first test image; The coefficient parameters for each channel are determined based on the load corresponding to the preset area of the grayscale image of each channel in the first test image, and the proportion of the preset area to the display area of the grayscale image of each channel. According to the method of claim 19, the compensation parameters include channel index parameters; the channel index parameters are determined as follows: Determine the second linear relationship between brightness and load in a pure white image; A second test image is determined, which includes grayscale images of each channel. Each grayscale image includes a preset region and a non-preset region. The preset region is a pure white image, and the non-preset region is a non-pure white image. Change the grayscale values of non-preset areas in each channel of the second test image to determine the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in each channel of the grayscale image. Based on the second linear relationship and the correspondence between the grayscale values of non-preset areas and the brightness of preset areas in each channel grayscale image, the load corresponding to the grayscale values of non-preset areas in each channel grayscale image is determined. Based on the principle that the load changes exponentially with grayscale, the exponential parameters of each channel are determined according to the load corresponding to the grayscale values of non-preset areas in the grayscale images of each channel. According to the method of claim 22, the step of determining the exponential parameter of each channel based on the load corresponding to the grayscale value of the non-preset region in the grayscale image of each channel, based on the exponential variation of load with grayscale, includes: Based on the load corresponding to the grayscale values of non-preset areas in the grayscale images of each channel, and the proportion of the preset area in the display area of each channel's grayscale images, the relationship curve between grayscale and load of each channel is fitted. Based on the relationship curve between grayscale and load of each channel, the load variation law of grayscale of each channel is determined. According to the method of claim 20, the first linear relationship between brightness and load at different gray levels is determined by: Based on the relationship curve between grayscale and brightness under maximum load, determine the maximum brightness corresponding to each channel grayscale of the pixel unit under maximum load; and based on the relationship curve between grayscale and brightness under minimum load, determine the minimum brightness corresponding to each channel grayscale of the pixel unit under minimum load. Based on the maximum brightness, minimum brightness, maximum load, and minimum load corresponding to each channel grayscale of the pixel unit, a first linear relationship between brightness and load under different grayscale levels is constructed. According to the method of claim 24, the relationship curve between grayscale and brightness under maximum or minimum load is determined by: A third test image is determined, which includes grayscale images of each channel, and each grayscale image of each channel includes a preset area and a non-preset area. By setting the non-preset area in the third test image to white, changing the size and grayscale of the preset area in each channel's grayscale image, and setting the non-preset area in the third test image to black, changing the size and grayscale of the preset area in each channel's grayscale image, the relationship between the load, grayscale, and brightness of each channel is determined. Based on the relationship between load, grayscale, and brightness of each channel, the relationship curves between grayscale and brightness of each channel under the maximum or minimum load are obtained by fitting. According to the method of claim 19, the brightness parameter includes a first brightness correction parameter; the first brightness correction parameter is determined in the following manner: Based on the linear relationship between the maximum brightness of the white image under the highest brightness that the display screen can display and the compensation coefficient, the linear variation law of the maximum brightness of the white image under different maximum brightness is determined. Based on the linear variation law of the maximum brightness of the white image under different maximum brightness levels, the first brightness correction parameter under the maximum brightness of the display screen is determined. According to the method of claim 26, the first brightness correction parameter includes a first scaling parameter and a first bias parameter; determining the first brightness correction parameter at the highest brightness of the display screen based on the linear variation law of the highest brightness of the white image under different maximum brightness levels includes: Based on the scaling degree of the maximum brightness change of the white image under different maximum brightness levels, determine the first scaling parameter for different maximum brightness levels; and/or, The first bias parameter for different maximum brightness levels is determined based on the degree of bias in the maximum brightness variation of the white image under different maximum brightness levels. According to the method of claim 19, the brightness parameter includes a second brightness correction parameter; the second brightness correction parameter is determined in the following manner: In high-brightness mode, based on the linear relationship between load and compensation coefficient, linear interpolation is performed between the maximum and minimum compensation coefficients to obtain n sub-linear relationships between load and compensation coefficient, where n is an integer greater than 1; the load is determined according to the image displayed on the screen. Based on the variation law of the compensation coefficient under different loads in the n sub-linear relationships, the second brightness correction parameter corresponding to the displayed current image is determined. According to the method of claim 28, the second brightness correction parameter includes a second scaling parameter and a second offset parameter; determining the second brightness correction parameter corresponding to the displayed current image based on the variation law of the compensation coefficients under different loads in the n sub-linear relationships includes: For each sub-linear relationship, based on the scaling degree of the compensation coefficient variation under different loads, determine the second scaling parameter corresponding to different loads in each sub-linear relationship; and/or, For each sub-linear relationship, the second bias parameter corresponding to different loads in each sub-linear relationship is determined based on the bias degree of the change in the compensation coefficient under different loads. A voltage drop compensation method, wherein the method includes: Acquire the current image and determine the input load on the display screen when the current image is displayed; Based on the sub-linear relationship corresponding to the input load among n sub-linear relationships of load and compensated brightness, determine the compensated brightness corresponding to the input load; The n sub-linear relationships mentioned above are obtained by linear interpolation between the maximum and minimum compensated brightness, based on the linear relationship between load and compensated brightness, where n is an integer greater than 1. An electronic device comprising a processor and a memory, the memory for storing a program executable by the processor, the processor for reading the program in the memory and performing the steps of the method according to any one of claims 19-30. A computer storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps of the method as described in any one of claims 19 to 30.