CN113228152B

CN113228152B - Device and method for controlling screen brightness

Info

Publication number: CN113228152B
Application number: CN201980085981.5A
Authority: CN
Inventors: 陳伯銘; 许景翔; 彭德彰; 刘洋; 罗琨
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2022-09-09
Anticipated expiration: 2039-05-17
Also published as: CN113228152A; WO2020232588A1

Abstract

An apparatus and method for controlling screen brightness, the apparatus comprising: the screen burning compensation module (104,1304) is used for acquiring a target gray-scale value or a reference gray-scale value when the current display brightness value of a target pixel point in the screen is inconsistent with the target brightness value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen; the digital-to-analog converter (103,1303) is used for controlling the display brightness of the target pixel point according to the target gray-scale value; or, the digital-to-analog converter (103,1303) is used for controlling the display brightness of the reference pixel point according to the reference gray-scale value; the display effect of the screen brightness can be effectively improved.

Description

Device and method for controlling screen brightness

Technical Field

The present disclosure relates to display devices, and particularly to a device and a method for controlling screen brightness.

Background

An Organic Light Emitting Diode (OLED) display device is a main development direction of a next-generation mobile phone panel because it has advantages of self-luminescence, thin thickness, high contrast, large viewing angle, and the like. Among them, the Active-matrix organic light emitting diode (AMOLED) is an important development point because it has better flexibility.

At present, organic high polymer materials such as OLED and AMOLED are usually adopted for the screen, and aging behaviors such as thermal aging, wet aging, and photo aging often occur. When the light emitting diodes in the screen age, their physical characteristics change accordingly, resulting in uneven light emission or reduced efficiency of a pixel or a region in the screen compared with other pixels, and the pixel or region is generally called burn-in or burn-in. For organic light emitting diodes (e.g., OLEDs) in a screen, the organic light emitting diodes are increasingly aged with the passage of time, resulting in greater and greater variations in physical characteristics of the organic light emitting diodes. In addition, the aging degree of different organic light emitting diodes in the screen may be different. When a light emitting diode corresponding to a certain pixel point is aged, the actually displayed brightness value of the pixel point is often different from the theoretical brightness value of the pixel point in an input image source, and the difference between the actually displayed brightness value of the pixel point and the theoretical brightness value of the pixel point is increased along with the aging degree of the light emitting diode. Burn-in compensation is the compensation removal of pixels or areas that experience aging. Therefore, in order to make the brightness of the image displayed on the screen consistent with the original brightness of the input image source, the brightness of the pixel point corresponding to the aged led in the screen needs to be compensated.

Disclosure of Invention

The embodiment of the application provides a device and a method for controlling screen brightness, which can effectively compensate the brightness of pixel points in a screen, so that the brightness of an image displayed on the screen is basically consistent with the original brightness of an input image source.

In a first aspect, an embodiment of the present application provides an apparatus for controlling screen brightness, where the apparatus includes: the screen burning compensation module is used for acquiring a target gray-scale value or a reference gray-scale value when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen; the digital-to-analog converter is used for controlling the display brightness of the target pixel point according to the target gray scale value; or, the digital-to-analog converter is used for controlling the display brightness of the reference pixel point according to the reference gray-scale value. When the current display brightness value of a target pixel point in the screen is inconsistent with the target brightness value, the brightness of the target pixel point is compensated to enable the target pixel point to display the target brightness value, or the brightness of the reference pixel point is compensated to enable the actually displayed brightness value of the reference pixel point to be matched with the current display brightness value of the target pixel point, so that the overall display effect of the screen is improved.

In the embodiment of the application, when the current display brightness value of the target pixel point in the screen is inconsistent with the target brightness value, the brightness of the target pixel point is compensated or the brightness of the pixel points except the target pixel point in the screen is compensated, so that the display effect of the screen can be effectively improved.

In an optional implementation manner, the burn-in compensation module is specifically configured to obtain the target gray level value or the reference gray level value when the current display brightness value is inconsistent with the target brightness value due to aging of a light emitting diode corresponding to the target pixel point, where the target brightness value is a theoretical brightness value of the target pixel point in an input image source; the digital-to-analog converter is specifically used for controlling the display brightness of the target pixel point to be the target brightness value according to the target gray scale value; or, the digital-to-analog converter is specifically configured to control the display brightness of the reference pixel point to be a reference brightness value according to the reference gray-scale value, where the reference brightness value is positively correlated with the current display brightness value.

In the implementation manner, when the current display brightness value is inconsistent with the target brightness value due to aging of the corresponding light emitting diode of the target pixel point in the screen, the brightness of the target pixel point is compensated to enable the target pixel point to display the target brightness value, or the brightness of the reference pixel point is compensated to enable the reference brightness value displayed by the reference pixel point, so that the problem that the screen display effect is seriously reduced due to inconsistency between the current display brightness value and the target brightness value of the target pixel point in the screen can be effectively solved.

In an optional implementation manner, the screen-burning compensation module is specifically configured to obtain the target gray-scale value when an aging degree of a light emitting diode corresponding to the target pixel point meets a preset condition, so that the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray-scale value; and when the aging degree of the light emitting diode corresponding to the target pixel point does not meet a preset condition, acquiring the reference gray-scale value so that the digital-to-analog converter controls the display brightness of the reference pixel point according to the reference gray-scale value.

When the aging degree of the light-emitting diode corresponding to the target pixel point meets a preset condition, compensating the brightness of the target pixel point, so that the target pixel point can display the target brightness value; when the aging degree of the light emitting diode corresponding to the target pixel point does not meet the preset condition, the target pixel point cannot display the target brightness value when the target pixel point is not aged even if the brightness of the target pixel point is compensated, that is, the aging degree of the target pixel point is relatively serious, and the loss of the display brightness caused by aging cannot be compensated. Therefore, when the aging degree of the light-emitting diode corresponding to the target pixel point does not meet the preset condition, the brightness of the reference pixel point is compensated, so that the display brightness of the reference pixel point of the target pixel point is adapted to the display brightness of the target pixel point. The purpose of compensating the brightness of the reference pixel point is to enable the overall display effect of the screen to be better.

In an optional implementation manner, the preset condition is that the target grayscale value is greater than a limit grayscale value. The gray scale value that can be processed by the digital-to-analog converter has a certain range, and in an optional case, the limit gray scale value is the maximum gray scale value that can be processed by the digital-to-analog converter.

In an optional implementation manner, the burn-in compensation module is specifically configured to determine the target gray-scale value or the reference gray-scale value based on a burn-in compensation lookup table, where the burn-in compensation lookup table is used to represent a corresponding relationship between an aging degree of the light emitting diode corresponding to the pixel point and the gray-scale compensation value. In this implementation manner, the screen burning compensation module can quickly determine the target gray scale value or the reference gray scale value based on the screen burning compensation lookup table, and the implementation is simple.

In an optional implementation manner, the apparatus further includes: the detection circuit is used for acquiring the feedback voltage of a target pixel driving circuit of the target pixel point, the target pixel driving circuit comprises the light emitting diode and a driving tube, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point; and the application processor AP is used for determining the burn-in compensation lookup table according to the feedback voltage and a pre-stored characteristic curve table, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged. The pre-stored characteristic curve table may include at least one set of corresponding relations between the voltage between the drain and the source of the driving tube and the current in the light emitting diode when the light emitting diode is under a specified aging degree. The specified degree of aging may be any degree of aging. The pre-stored characteristic curve table may include a plurality of sets of corresponding relations representing the voltage between the drain and the source of the driving tube and the current in the light emitting diode when the light emitting diode is under different aging degrees. The feedback voltage is used to determine the current aging of the led.

In one possible implementation, the detection circuit may be an analog-to-digital converter ADC.

In this implementation manner, the application processor can accurately and quickly determine gray scale compensation values corresponding to the pixel points corresponding to the light emitting diodes with different aging degrees according to the feedback voltage and the pre-stored characteristic curve table.

In an optional implementation, the apparatus further comprises: the detection circuit is used for acquiring the feedback voltage of a target pixel driving circuit of the target pixel point, the target pixel driving circuit comprises a light emitting diode, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point; the application processor AP is used for determining the target gray-scale value or the reference gray-scale value according to the feedback voltage and a pre-stored characteristic curve table and storing the target gray-scale value or the reference gray-scale value in a memory, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode is at a specified aging degree and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed; the screen burning compensation module is specifically configured to obtain the target gray scale value or the reference gray scale value from the memory.

In the implementation mode, the application processor calculates the gray scale compensation values corresponding to the pixel points of the light emitting diodes with different aging degrees according to the feedback voltage and the pre-stored characteristic curve table, the calculated compensation values are more accurate, and the AP calculates the compensation values according to the aging degrees instead of storing a large number of compensation values in advance in the memory, so that the storage space is saved.

In an optional implementation manner, the AP is specifically configured to determine a first compensation value according to the feedback voltage and the pre-stored characteristic curve table; the digital-to-analog converter is further configured to obtain an intermediate driving voltage according to the first compensation value, where the intermediate driving voltage is used to control the target pixel driving circuit; the AP is specifically configured to determine the target gray scale value according to the intermediate driving voltage and the pre-stored photoelectric characteristic curve table.

In the implementation mode, the application processor determines two gray scale compensation values in sequence, the screen burning compensation module can compensate the brightness of the target pixel point in sequence twice, and the compensation precision is high.

In an optional implementation, the target pixel driving circuit further includes a driving tube, and the pre-stored characteristic curve table includes: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is at a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

The pre-stored characteristic curve table includes: the aging degree of the light emitting diodes corresponding to each group of aging compensation corresponding relation is different, and the voltage between the grid electrode and the source electrode of the driving tube corresponding to each group of photoelectric characteristic corresponding relation is different. The device for controlling the screen brightness can store one or more groups of discrete points, and each group of discrete points corresponds to an aging compensation corresponding relation; one or more aging compensation curves can also be stored, and each group of aging compensation curves corresponds to an aging compensation corresponding relation; one or more calculation formulas may also be stored, each representing an aging compensation correspondence. The device for controlling the screen brightness can store one or more groups of discrete points, and each group of discrete points corresponds to a photoelectric characteristic corresponding relation; one or more photoelectric characteristic curves can be stored, and each group of photoelectric characteristic curves corresponds to a corresponding relation of photoelectric characteristics; one or more calculation formulas may also be stored, and each calculation formula represents one photoelectric characteristic corresponding relationship. In the implementation mode, the application processor can accurately and quickly determine the target gray-scale value or the reference gray-scale value according to the feedback voltage, the aging compensation corresponding relation and the photoelectric characteristic corresponding relation.

In an optional implementation manner, the AP is specifically configured to determine a target aging compensation corresponding relationship from the pre-stored characteristic curve table according to the feedback voltage, where the target aging compensation corresponding relationship represents a corresponding relationship between a voltage between a drain and a source of the driving tube and a current of the light emitting diode when the light emitting diode corresponding to the target pixel point is at the aging degree of the current time; determining a first reference point according to the target aging compensation corresponding relation, wherein the current of the light emitting diode corresponding to the first reference point is theoretical current, the theoretical current is the current in the light emitting diode when the target pixel point displays the theoretical brightness value, and the theoretical current in the target aging compensation corresponding relation corresponds to reference voltage; determining a target photoelectric characteristic corresponding relation according to the first reference point, wherein the theoretical current in the target photoelectric characteristic corresponding relation corresponds to the reference voltage; determining the voltage between the drain electrode and the source electrode of the driving tube corresponding to the target photoelectric characteristic corresponding relation as a first target voltage; and determining the target gray-scale value of the current moment according to the first target voltage.

In the implementation mode, the application processor can accurately determine the target gray-scale value which enables the current in the aged light-emitting diode to be the theoretical current, and the implementation is simple.

In an optional implementation manner, the apparatus further comprises a first Gamma corrector, a Mura corrector and a second Gamma corrector; before the obtaining of the target gray-scale value or the reference gray-scale value, the method further includes: the first Gamma corrector determines an initial brightness value corresponding to the target pixel point at the current gear of brightness adjustment according to a first Gamma correction table, wherein the first Gamma correction table is a Gamma correction relation between a display brightness value and a gray level value at the current gear; the Mura corrector performs uniformity compensation Demura on the initial brightness values of the target pixel points to obtain target brightness values; the second Gamma corrector determines the initial gray scale value corresponding to the target brightness value according to a preset second Gamma correction table; the second Gamma correction table is used for displaying the Gamma correction relation between the brightness value and the gray value under the designated gear of brightness adjustment, and the first Gamma correction table is obtained according to the second Gamma correction table; and when the target pixel point is not aged in the corresponding light emitting diode, the digital-to-analog converter controls the display brightness of the target pixel point to be the target brightness value according to the initial gray scale value.

In order to make the Gamma correction relationship between the gray-scale value input by each pixel point in the screen and the displayed brightness value conform to the Gamma curve at different shift positions of brightness adjustment, theoretically, the screen needs to be measured at each shift position of brightness adjustment, so as to obtain the Gamma curves corresponding to different shift positions and respectively store the Gamma curves in a register or a memory. Optionally, the designated gear is a gear for brightness adjustment corresponding to the maximum brightness value of the screen. That is, the second gamma correction table may correspond to a gamma2.2 curve. In this implementation manner, the device only stores the Gamma curves (i.e., the second Gamma correction table) corresponding to the gray values input by the screen pixel points and the displayed brightness values at the specified gear of a certain brightness adjustment, and calculates the Gamma curves (i.e., the first Gamma correction table) corresponding to the input gray values and the displayed brightness values at other gears of the brightness adjustment based on the Gamma curves. That is, the device only needs to store one Gamma curve, and the occupied storage space can be effectively reduced.

In an optional implementation manner, the AP is specifically configured to determine, according to the feedback voltage, a first source voltage of the driving tube at the current time, where the first source voltage is related to a current aging degree of the target pixel; obtaining a first compensation voltage according to the difference between the first source voltage and an initial voltage, wherein the initial voltage is the voltage at two ends of the light-emitting diode when a target pixel point displays a target brightness value when the light-emitting diode is not aged; calculating the sum of the first compensation voltage and the initial driving voltage to obtain an intermediate driving voltage; sending a first compensation value corresponding to the intermediate driving voltage to a digital-to-analog converter; the digital-to-analog converter is also used for obtaining an intermediate driving voltage according to the first compensation value; the intermediate driving voltage is used for controlling the target pixel driving circuit; the detection circuit is also used for acquiring a target feedback voltage of the target pixel driving circuit under the driving of the intermediate driving voltage; the AP is specifically used for determining a second compensation value according to the target feedback voltage and a pre-stored characteristic curve table; the second compensation value is sent to a digital-to-analog converter. The initial driving voltage is the current driving voltage of the target pixel driving circuit.

In an optional implementation, the apparatus further comprises: a first Gamma corrector for determining the initial gray scale value corresponding to the target brightness value.

In an optional implementation, the apparatus further comprises: and the Mura corrector is used for performing uniformity compensation Demura on the target pixel points to obtain the target brightness values.

In the implementation mode, the nonuniform phenomenon of the screen can be effectively eliminated by performing Demura on the target pixel point.

In an optional implementation manner, the initial driving voltage is further used to control a reference pixel driving circuit, so that the brightness displayed by the reference pixel point is the target brightness value; the reference brightness value is equal to the brightness value displayed by the target pixel point under the driving of the initial driving voltage by the target pixel driving circuit.

In the implementation mode, under the condition that the brightness of the target pixel point is compensated and the target brightness value can not be displayed, the screen burning compensation is carried out on the reference pixel point so that the brightness value displayed by the reference pixel point is the same as the current brightness value displayed by the target pixel point, and the display effect of the screen can be improved.

In a second aspect, an embodiment of the present application provides another apparatus for controlling screen brightness, including: an application processor AP and a display driver integrated circuit DDIC, the DDIC including a burn-in compensation module and a digital-to-analog converter; the AP is used for calculating an aging compensation value according to the feedback voltage of the target pixel point and a pre-stored characteristic curve table; the screen burning compensation module is used for obtaining a target gray scale value according to the aging compensation value; and the digital-to-analog converter is used for controlling the display brightness value of the target pixel point according to the target gray scale value. The feedback voltage may be a feedback voltage of a target pixel driving circuit of the target pixel point.

In the embodiment of the application, the device for controlling the screen brightness calculates compensation values corresponding to different aging degrees according to the feedback voltage and several pre-stored groups of typical characteristic curves by the AP, and then adjusts the brightness of the target pixel point according to the compensation values by the screen burning compensation module and the DAC in the DDIC, so as to improve the brightness value deviation of the target pixel point caused by aging.

In an optional implementation, the DDIC further comprises: and the detection circuit is used for acquiring the feedback voltage, and the feedback voltage is related to the aging degree of the light-emitting diode corresponding to the target pixel point.

In the implementation mode, the application processor can determine the aging degree of the light-emitting diode according to the feedback voltage, and then compensate the brightness of the target pixel point corresponding to the aged light-emitting diode.

In an optional implementation manner, the burn-in compensation lookup table is used for representing a corresponding relationship between the aging degree of the light emitting diode corresponding to the pixel point and the gray scale compensation value. In the implementation mode, the burn-in compensation module can quickly determine the aging gray scale value based on the burn-in compensation lookup table, and the implementation is simple.

In an optional implementation manner, the detection circuit is specifically configured to obtain a feedback voltage of a target pixel driving circuit of the target pixel, where the target pixel driving circuit includes the light emitting diode and a driving tube; and the application processor AP is used for determining the burn-in compensation lookup table according to the feedback voltage and a pre-stored characteristic curve table, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged. The pre-stored characteristic curve table may include at least one set of corresponding relations between the voltage between the drain and the source of the driving tube and the current in the light emitting diode when the light emitting diode is under a specified aging degree.

In an optional implementation manner, the detection circuit is specifically configured to obtain a feedback voltage of a target pixel driving circuit of the target pixel point, where the target pixel driving circuit includes a light emitting diode, and the feedback voltage is related to an aging degree of the light emitting diode corresponding to the target pixel point; an application processor AP, configured to determine the aging compensation value according to the feedback voltage and a pre-stored characteristic curve table, and store the aging compensation value in a memory, where the characteristic curve table is used to represent a correspondence relationship between a voltage between a drain and a source of the driving tube and a current in the light emitting diode when the light emitting diode is at a specified aging degree, and to represent a correspondence relationship between a voltage between the drain and the source and a current in the light emitting diode when the voltage between the gate and the source of the driving tube is fixed; the burn-in compensation module is specifically configured to obtain the aging compensation value from the memory.

In this implementation manner, the application processor can accurately and quickly obtain the aging compensation values corresponding to the pixel points corresponding to the leds with different aging degrees according to the feedback voltage and the pre-stored characteristic curve table.

In an optional implementation manner, the AP is specifically configured to determine a first compensation value according to the feedback voltage and the pre-stored characteristic curve table; the digital-to-analog converter is further configured to obtain an intermediate driving voltage according to the first compensation value, where the intermediate driving voltage is used to control the target pixel driving circuit; the AP is specifically configured to determine the aging compensation value according to the intermediate driving voltage and the pre-stored photoelectric characteristic curve table.

In an optional implementation, the target pixel driving circuit further includes a driving tube, and the pre-stored characteristic curve table includes: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is in a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

In the implementation mode, the application processor can accurately and quickly determine the aging compensation value according to the feedback voltage, the aging compensation corresponding relation and the photoelectric characteristic corresponding relation.

In an optional implementation manner, the AP is specifically configured to determine a target aging compensation corresponding relationship from the pre-stored characteristic curve table according to the feedback voltage, where the target aging compensation corresponding relationship represents a corresponding relationship between a voltage between a drain and a source of the driving tube and a current of the light emitting diode when the light emitting diode corresponding to the target pixel point is at the aging degree of the current time; determining a first reference point according to the target aging compensation corresponding relation, wherein the current of the light emitting diode corresponding to the first reference point is theoretical current, the theoretical current is the current in the light emitting diode when the target pixel point displays the theoretical brightness value, and the theoretical current in the target aging compensation corresponding relation corresponds to reference voltage; determining a target photoelectric characteristic corresponding relation according to the first reference point, wherein the theoretical current in the target photoelectric characteristic corresponding relation corresponds to the reference voltage; determining the voltage between the drain electrode and the source electrode of the driving tube corresponding to the target photoelectric characteristic corresponding relation as a first target voltage; and determining the aging compensation value at the current moment according to the first target voltage.

In a third aspect, an embodiment of the present application provides another apparatus for controlling screen brightness, including: the first Gamma corrector is used for carrying out first Gamma correction on the screen according to a first Gamma correction table so that the brightness value displayed by the target pixel point in the screen is the same as the theoretical brightness value of the target pixel point in the source image; the first Gamma correction table is a Gamma correction relation between the brightness value of the screen and the initial input gray level value under the specified gear of brightness adjustment; a Mura corrector, which is used for performing Demura on the screen after the first Gamma correction so as to enable the display brightness of the screen to be uniform; the second Gamma corrector is used for performing second Gamma correction on the screen according to a second Gamma correction table, and the second Gamma correction table is a Gamma correction table under the current brightness display gear; the second Gamma correction table is obtained according to the first Gamma correction table.

In the embodiment of the application, the device only stores the Gamma curves corresponding to the gray values input by the screen pixel points and the displayed brightness values under the appointed gear of the brightness adjustment, and calculates the Gamma curves corresponding to the input gray values and the displayed brightness values under other gears of the brightness adjustment based on the Gamma curves, so that the occupied storage space can be effectively reduced.

In a fourth aspect, an embodiment of the present application provides a method for controlling screen brightness, which is applied to a device for controlling screen brightness, where the device includes a burn-in compensation module and a digital-to-analog converter, and the method includes: the screen burning compensation module acquires a target gray-scale value or a reference gray-scale value when a target pixel point in a screen is inconsistent with a current display brightness value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen; the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray scale value; or controlling the display brightness of the reference pixel point according to the reference gray-scale value.

In an optional implementation manner, the obtaining the target gray-scale value or the reference gray-scale value includes: the burn-in compensation module acquires the target gray level value or the reference gray level value when the current display brightness value is inconsistent with the target brightness value due to aging of a light emitting diode corresponding to the target pixel point, wherein the target brightness value is a theoretical brightness value of the target pixel point in an input image source; the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray scale value; or, controlling the display brightness of the reference pixel point according to the reference gray-scale value includes: the digital-to-analog converter controls the display brightness of the target pixel point to be the target brightness value according to the target gray scale value; or controlling the display brightness of the reference pixel point to be a reference brightness value according to the reference gray-scale value, wherein the reference brightness value is positively correlated with the current display brightness value.

In an optional implementation manner, the obtaining the target gray-scale value or the reference gray-scale value includes: the screen burning compensation module acquires the target gray scale value when the aging degree of the light emitting diode corresponding to the target pixel point meets a preset condition, so that the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray scale value; and the screen burning compensation module acquires the reference gray-scale value when the aging degree of the light-emitting diode corresponding to the target pixel point does not meet a preset condition, so that the digital-to-analog converter controls the display brightness of the reference pixel point according to the reference gray-scale value.

In an optional implementation manner, the obtaining the target gray-scale value or the reference gray-scale value includes: the screen burning compensation module determines the target gray scale value or the reference gray scale value based on a screen burning compensation lookup table, and the screen burning compensation lookup table is used for representing the corresponding relation between the aging degree of the light emitting diode corresponding to the pixel point and the screen burning compensation value.

In an alternative implementation, the apparatus further comprises a detection circuit and an application processor AP; before the burn-in compensation module determines the target gray scale value or the reference gray scale value based on a burn-in compensation look-up table, the method further includes: the detection circuit acquires a feedback voltage of a target pixel driving circuit of the target pixel point, the target pixel driving circuit comprises the light emitting diode and a driving tube, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point; and the application processor AP determines the burn-in compensation lookup table according to the feedback voltage and a pre-stored characteristic curve table, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged.

In an alternative implementation, the apparatus further comprises a detection circuit and an application processor AP; before the obtaining of the target gray-scale value or the reference gray-scale value, the method further includes: the detection circuit acquires a feedback voltage of a target pixel driving circuit of the target pixel point, the target pixel driving circuit comprises a light emitting diode, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point; the application processor AP determines the target gray-scale value or the reference gray-scale value according to the feedback voltage and a pre-stored characteristic curve table, and stores the target gray-scale value or the reference gray-scale value in a memory, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the gate electrode and the source electrode of the driving tube is fixed; the acquiring of the target gray-scale value or the reference gray-scale value includes: and the screen burning compensation module acquires the target gray-scale value or the reference gray-scale value from the memory.

In an optional implementation manner, the determining, by the application processor AP, the target gray scale value or the reference gray scale value according to the feedback voltage and a pre-stored characteristic curve table includes: the AP determines a first compensation value according to the feedback voltage and the pre-stored characteristic curve table, so that the digital-to-analog converter obtains an intermediate driving voltage according to the first compensation value, and the intermediate driving voltage is used for controlling the target pixel driving circuit; and the AP determines the target gray-scale value according to the intermediate driving voltage and the pre-stored photoelectric characteristic curve table.

In an optional implementation manner, the determining, by the application processor AP, the target gray scale value or the reference gray scale value according to the feedback voltage and a pre-stored characteristic curve table includes: the AP determines a target aging compensation corresponding relation from the pre-stored characteristic curve table according to the feedback voltage, wherein the target aging compensation corresponding relation represents the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current of the light-emitting diode when the light-emitting diode corresponding to the target pixel point is at the aging degree of the current moment; determining a first reference point according to the target aging compensation corresponding relation, wherein the current of the light emitting diode corresponding to the first reference point is theoretical current, the theoretical current is the current in the light emitting diode when the target pixel point displays the theoretical brightness value, and the theoretical current in the target aging compensation corresponding relation corresponds to reference voltage; determining a target photoelectric characteristic corresponding relation according to the first reference point, wherein the theoretical current in the target photoelectric characteristic corresponding relation corresponds to the reference voltage; determining the voltage between the drain electrode and the source electrode of the driving tube corresponding to the target photoelectric characteristic corresponding relation as a first target voltage; and determining the target gray-scale value at the current moment according to the first target voltage.

In an optional implementation manner, the apparatus further comprises a first Gamma corrector, a Mura corrector and a second Gamma corrector; before the target gray-scale value or the reference gray-scale value is obtained, the method further includes: the first Gamma corrector determines an initial brightness value corresponding to the target pixel point at the current gear of brightness adjustment according to a first Gamma correction table, wherein the first Gamma correction table is a Gamma correction relation between a display brightness value and a gray level value at the current gear; the Mura corrector performs uniformity compensation Demura on the initial brightness values of the target pixel points to obtain target brightness values; the second Gamma corrector determines the initial gray scale value corresponding to the target brightness value according to a preset second Gamma correction table; the second Gamma correction table is used for displaying the Gamma correction relation between the brightness value and the gray value under the designated gear of brightness adjustment, and the first Gamma correction table is obtained according to the second Gamma correction table; and when the target pixel point is not aged in the corresponding light emitting diode, the digital-to-analog converter controls the display brightness of the target pixel point to be the target brightness value according to the initial gray scale value.

In a fifth aspect, an embodiment of the present application provides another method for controlling screen brightness, which is applied to an apparatus for controlling screen brightness, and the apparatus includes: an application processor AP and a display driver integrated circuit DDIC, the DDIC including a burn-in compensation module and a digital-to-analog converter; the method comprises the following steps: the AP calculates an aging compensation value according to the feedback voltage of the target pixel point and a pre-stored characteristic curve table; the screen burning compensation module obtains a target gray scale value according to the aging compensation value; and the digital-to-analog converter controls the display brightness value of the target pixel point according to the target gray scale value. The feedback voltage may be a feedback voltage of a target pixel driving circuit of the target pixel point.

In an optional implementation, the DDIC further comprises: a detection circuit; before the AP calculates the aging compensation value according to the feedback voltage of the target pixel point and the pre-stored characteristic curve table, the method further includes: the detection circuit obtains the feedback voltage, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point.

In an optional implementation, the apparatus further comprises an application processor AP; before the AP calculates the aging compensation value according to the feedback voltage of the target pixel point and the pre-stored characteristic curve table, the method further includes: and the AP is used for determining the burn-in compensation lookup table according to the feedback voltage and a pre-stored characteristic curve table, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged. In this implementation manner, the application processor can accurately and quickly obtain gray scale compensation values corresponding to the pixel points corresponding to the leds with different aging degrees according to the feedback voltage and the pre-stored characteristic curve table.

In an alternative implementation, the pre-stored characteristic curve table includes: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is in a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

In the implementation mode, the application processor can accurately and quickly determine the target gray-scale value according to the feedback voltage, the aging compensation corresponding relation and the photoelectric characteristic corresponding relation.

In a sixth aspect, an embodiment of the present application provides a terminal device, where the terminal device includes: the device comprises a Mura corrector, a first Gamma corrector, a digital-to-analog converter, a processor and a screen; the Mura corrector is used for performing Demura on a target pixel point in the screen to obtain a target brightness value corresponding to the target pixel point, and the target brightness value is a theoretical brightness value of the target pixel point in an input image source; a first Gamma corrector for determining an input gray level value corresponding to the target luminance value; the digital-to-analog converter is used for obtaining an initial driving voltage according to the input gray scale value, and the initial driving voltage is used for controlling a target pixel driving circuit so as to enable the brightness displayed by the target pixel point to be the target brightness value; and the processor is used for determining a target gray-scale value of the aged target pixel point when the target pixel point is aged, wherein the brightness displayed by the aged target pixel point under the driving of the initial driving voltage is not equal to the target brightness value, and the target gray-scale value is the gray-scale value when the aged target pixel point displays the target brightness value.

In a seventh aspect, an embodiment of the present application provides a chip, where the chip includes: a burn-in compensation module and a digital-to-analog converter; the screen burning compensation module is used for acquiring a target gray-scale value or a reference gray-scale value when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen; the digital-to-analog converter is used for controlling the display brightness of the target pixel point according to the target gray scale value; or, the digital-to-analog converter is used for controlling the display brightness of the reference pixel point according to the reference gray-scale value.

In an eighth aspect, the present application provides a computer-readable storage medium storing a computer program comprising program instructions that, when executed by a processor, perform the operations performed by the application processor in the fourth to fifth aspects and in alternative implementations.

In a ninth aspect, the present application provides a computer program product comprising instructions which, when run on a computer or processor, cause the computer or processor to perform the method as in the fourth to fifth aspects above or any possible implementation thereof.

Drawings

Fig. 1 is a schematic structural diagram of a device for screen brightness according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another apparatus provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of a target aging compensation curve and a target optical-electrical characteristic curve according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an aging compensation circuit according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of an optoelectronic characteristic curve and an aging compensation curve according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of another aging compensation circuit according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of another optoelectronic characteristic curve and an aging compensation curve provided in the embodiments of the present application;

FIG. 8 is a schematic diagram of another optoelectronic characteristic curve and an aging compensation curve provided in the embodiments of the present application;

fig. 9 is a schematic diagram of a pixel point of a screen according to an embodiment of the present application;

FIG. 10 is a schematic structural diagram of another apparatus provided in an embodiment of the present application;

fig. 11 is a schematic structural diagram of another aging compensation circuit according to an embodiment of the present disclosure;

fig. 12 is a flowchart illustrating a method for controlling screen brightness according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

The terms "first," "second," and "third," etc. in the description and claims of the present application and the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprises" and "comprising," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such as a list of steps or elements. A method, system, article, or apparatus is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, system, article, or apparatus. "and/or" is used to indicate that one or both of the objects are selected between which it is connected. For example "A and/or B" means A, B or A + B.

When the screen is displayed, because the sensitivities of human eyes to different brightnesses are inconsistent, the brightness of the image displayed by the screen and the original brightness of the original input image are usually inconsistent but have a certain deviation. At this time, the image output from the screen is distorted compared with the input image, which causes a large difference between the display color of the screen and the color of the input image, or causes the display of the image by the screen to be too bright or too dark. Illustratively, when the color of the screen display changes from black to white, the input gray scale value of the screen also changes, but the change is not linear, the physical characteristics of the screen display determine that if the input gray scale value changes linearly, the output brightness value is not linear, and in order to ensure that the displayed brightness value does not deviate from the brightness value expected to be presented by the screen, the input gray scale value of the screen needs to be corrected, i.e. the screen needs to be subjected to a Gamma correction process to display the expected brightness. The Gamma correction is carried out on the screen, so that the change relation between the gray value input by the screen and the output brightness can meet a corresponding relation curve, and the curve is a Gamma curve. When the input gray scale value and the output brightness value of the screen meet the Gamma curve, the screen can display the preset brightness and color. When the Gamma curve is used for brightness correction of the screen, when the overall brightness of the screen changes or the input and output characteristics of individual pixel points on the screen change, the overall display of the screen brightness is affected, so that the brightness correction of the screen is needed to enable the screen to display normal brightness. In order to make the brightness of the image displayed on the screen consistent with the original brightness of the original input image, it is necessary to not only perform brightness correction on the screen, but also solve the problem of uneven brightness (Mura) of individual pixels on the screen during display, the problem of screen aging, and the like.

When the screen is an AMOLED or other screen, in the production process of the AMOLED display panel, the light emitting characteristics of the individual pixels may change due to process reasons (e.g., evaporation uniformity of the whole surface, film thickness control, etc.), and at this time, when the driving voltage of the individual pixels is the same, the current flowing through the individual pixels may have different magnitudes, which may cause uneven brightness (Mura) of the individual pixels on the screen during display. In order to correct the Mura phenomenon of the screen, the screen needs to perform compensation and elimination of the Mura phenomenon, i.e., a Demura step. And thus a step for eliminating the Mura phenomenon may be further added to the brightness control method of the screen. Screens such as OLEDs are made of organic polymer materials, and are often prone to aging behaviors such as thermal aging, wet aging and photo aging. As the organic material ages, its physical properties change, resulting in uneven or reduced efficiency of light emission at a pixel or a region on the screen compared to other surroundings. Therefore, in the brightness control method of the screen, aging compensation (also called screen burning compensation) needs to be performed on the aged pixel points in the screen to solve the aging problem of the screen. At present, no screen burning compensation related technology exists in the field of screens of mobile terminals such as mobile phones and tablet computers, and the problem of uneven brightness caused by aging of the screens at any time cannot be solved. Demura (also called uniformity compensation), Gamma correction and burn-in compensation all affect each other and all aim to make the brightness of the image displayed by the screen consistent with the original brightness of the original input image. In the currently adopted brightness control scheme of the screen, Demura, Gamma correction and screen burning compensation are not comprehensively considered when the brightness of the screen is adjusted, so that the display effect of the screen display brightness is poor. Therefore, it is necessary to research a brightness apparatus and a brightness control method that comprehensively consider Gamma correction, Demura, and burn-in compensation for a screen.

Fig. 1 is a schematic structural diagram of a device for screen brightness according to an embodiment of the present application. As shown in fig. 1, the apparatus 10 includes:

the screen burning compensation module 104 is configured to obtain a target gray scale value or a reference gray scale value when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, where the target gray scale value is a gray scale value for compensating brightness of the target pixel point, the reference gray scale value is a gray scale value for compensating brightness of a reference pixel point, and the reference pixel point is another pixel point except the target pixel point in the screen;

a Digital to analog converter (DAC) 103, configured to control the display brightness of the target pixel according to the target gray-scale value; or, the digital-to-analog converter 103 is configured to control the display brightness of the reference pixel point according to the reference gray-scale value.

Optionally, the apparatus 10 further comprises: the Mura corrector 101 is configured to perform Demura on a target pixel point in the screen to obtain a target brightness value corresponding to the target pixel point, where the target brightness value is a theoretical brightness value of the target pixel point in an input image source. Optionally, the Mura corrector 101 may perform Demura on each pixel point in the screen by using pre-stored Demura data to eliminate a Mura phenomenon in the screen.

The first Gamma corrector 102 is configured to determine an input gray level value corresponding to the target brightness value.

The dac103 is further configured to obtain an initial driving voltage according to the input gray scale value, where the initial driving voltage is used to control a target pixel driving circuit, so that the brightness displayed by the target pixel is the target brightness value. The initial driving voltage is a driving voltage which enables the brightness value of the target pixel point to be the target brightness value before the light emitting diode corresponding to the target pixel point is not aged. That is, if the led corresponding to the target pixel point is not aged, the luminance value of the target pixel point is the target luminance value when the driving voltage of the target pixel driving circuit is the initial driving voltage. The light emitting diode may be an AMOLED, an OLED, or the like.

In order to enable the Gamma correction relationship between the gray-scale value input by each pixel point in the screen and the displayed brightness value to accord with the Gamma curve at different gears of brightness adjustment, theoretically, the screen needs to be measured at each gear of brightness adjustment so as to obtain the Gamma curves corresponding to different gears and respectively store the Gamma curves in a register or a memory, but the method needs to occupy a plurality of production lines for measurement and simultaneously occupies a large amount of storage space. In the embodiment of the application, only the Gamma curves corresponding to the gray values input by the screen pixel points and the displayed brightness values at the specified gear of a certain brightness adjustment can be measured, and the Gamma curves corresponding to the input gray values and the displayed brightness values at other gears of the brightness adjustment can be calculated based on the Gamma curves. In an optional case, a shift corresponding to a maximum brightness value that can be displayed on the screen may be selected as an assigned shift for brightness adjustment, and a Gamma correction relationship between a gray value input to the screen and a displayed brightness value is measured at the shift for brightness adjustment to obtain a set of Gamma curves (corresponding to the second Gamma correction table), where the Gamma curves include all brightness values of the screen from the minimum brightness value to the maximum brightness value. After the gear is adjusted, the brightness value of the screen display is smaller than that of the designated gear of the brightness adjustment, so that the brightness value of the screen display and the corresponding input gray level value can still be found in the Gamma curve. Therefore, the Gamma curve at the shift position of brightness adjustment corresponding to the maximum brightness value can be stored in a memory or a register in advance, and after the shift position of brightness adjustment is changed, the Gamma curves (corresponding to the first Gamma correction table) of the input gray-scale value and the displayed brightness value at the shift positions of other brightness adjustments are calculated based on the previously stored Gamma curve, so that the corresponding relation between the input gray-scale value and the displayed brightness value at other shift positions is corrected.

In an alternative implementation, the apparatus 10 further comprises:

the second Gamma corrector 105 is used for determining the corresponding initial brightness value of the target pixel point under the current gear according to the first Gamma correction table;

a Mura corrector 101, specifically configured to perform Demura on the initial brightness value of the target pixel point to obtain a target brightness value;

a first Gamma corrector 102, specifically configured to determine an input gray level value corresponding to the target luminance value according to a second Gamma correction table; the second Gamma correction table is a Gamma correction relation between the brightness value of the screen and the initial input gray level value under the specified gear of brightness adjustment; the first gamma correction table is obtained according to the second gamma correction table.

The first gamma correction table is obtained by a series of operations according to the second gamma correction table. The correction performed by the first Gamma corrector 102 and the correction performed by the second Gamma corrector 105 make Gamma correction relations between gray-scale values input by each pixel point in the screen and displayed brightness values conform to Gamma curves at different levels of brightness adjustment. To help understand the correction performed by the first Gamma corrector 102 and the correction performed by the second Gamma corrector 105, the operations implemented by the first Gamma corrector 102, the Mura corrector 101, and the second Gamma corrector are described below from the viewpoint of luminance correction.

The first Gamma corrector 102 performs first Gamma correction on the screen according to the second Gamma correction table, so that the brightness value displayed by the target pixel point in the screen is the same as the theoretical brightness value of the target pixel point in the source image; the Mura corrector 101 performs Demura on the screen after the first gamma correction, so that the display brightness of the screen is uniform; and the second gamma corrector performs second gamma correction on the screen according to the first gamma correction table.

The second Gamma correction table is the Gamma correction relation between the brightness value of the screen and the input gray-scale value under the specified gear of brightness adjustment. Optionally, the designated gear is a gear for brightness adjustment corresponding to the maximum brightness value of the screen. That is, the second gamma correction table may correspond to a gamma2.2 curve. It can be understood that the input gray level values and luminance values corrected by the first Gamma corrector 102 conform to the Gamma2.2 curve. The Mura corrector 101 may Demura the screen using a fixed and invariant Mura compensation table (i.e., compensation data) so that the display luminance of the screen is uniform. The Mura corrector 101 is used for compensating the relationship between the gray scale value and the brightness value of each pixel point in the screen, so that the input and output characteristics of each pixel point on the screen are kept consistent, and the possible Mura phenomenon in the screen is eliminated. That is to say, after Demura is performed on the screen by the Mura corrector 101, the input and output characteristics of each pixel point in the screen are consistent. To help understand the role of the Mura corrector 101, it can be considered that the input and output characteristics of each pixel point in the screen are consistent and the Mura corrector 101 does not exist. It can be understood that the Mura corrector 101 adjusts the input/output characteristics of each pixel point in the screen, and has no influence on the brightness adjustment. The first Gamma correction table is a Gamma correction table (corresponding to a Gamma curve of the current gear) under the current brightness display gear; the first gamma correction table is obtained according to the second gamma correction table. After the device 10 adjusts the gear each time, the first Gamma corrector 102 obtains the Gamma curve of the current gear. That is, the device 10 obtains a first gamma correction table according to the second gamma correction table after adjusting the shift position each time. The second gamma correction table is fixed and invariable, and the device stores a new first gamma correction table after adjusting the gear each time. The device 10 only needs to store the second gamma correction table and obtain the first gamma correction table according to the currently adjusted gear, and does not need to store the gamma correction tables under all gears, so that the occupied storage space is greatly reduced. The first Gamma corrector 102 and the second Gamma corrector 105 perform operations so that the input gray-scale value and the displayed brightness value of each pixel point at the current gear both conform to the Gamma curve. The device 10 is arranged with two Gamma correctors in order to reduce the occupied memory space.

From the perspective of brightness correction, the input gray level value and the displayed brightness value of each pixel point under the current gear both conform to a Gamma curve by the operation executed by the first Gamma corrector 102 and the second Gamma corrector 105; the Mura corrector 101 keeps the input and output characteristics of each pixel point in the screen consistent. It can be understood that the input gray scale value obtained by the processing of the second Gamma corrector 105, the Mura corrector 101 and the first Gamma corrector 102 is a gray scale value enabling the target pixel point before aging to display the target brightness value, and the input gray scale value and the target brightness value conform to a Gamma curve.

In the device 10, the second Gamma corrector 105 may determine, according to the first Gamma correction table, an initial brightness value (i.e., a brightness value to be displayed for each pixel point) corresponding to each pixel point in the screen at the current shift; the Mura corrector 101 can perform Demura on each pixel point to obtain the brightness value of each pixel point after uniformity compensation, so that the Mura phenomenon in a screen can be eliminated; the first Gamma corrector 102 may determine an input gray level value corresponding to the luminance value of each pixel point based on a preset second Gamma correction table; the digital-to-analog converter 103 converts the input gray scale value into a driving voltage, the driving voltage is a voltage supplied to a pixel driving circuit corresponding to each pixel point, and when the driving voltage changes, the display brightness of the pixel point also changes, so that the display brightness of each pixel point can be adjusted by changing the input gray scale value; the screen burning compensation module 104 obtains a compensation gray scale value corresponding to each pixel point, and the digital-to-analog converter 103 converts the compensation gray scale value corresponding to each pixel point into a corresponding driving voltage, thereby adjusting the brightness of each aged pixel point. It can be understood that, in the case that the light emitting diodes corresponding to each pixel point in the screen are not aged, the brightness of the image displayed on the screen can be consistent with the theoretical brightness of the original input image (i.e., the image source) through the processing operations of the second Gamma corrector 105, the Mura corrector 101, the first Gamma corrector 102 and the digital-to-analog converter 103. The device 10 uses the screen after Demura as the compensation reference point during screen burning compensation, and uses the screen burning compensation module 104 to obtain the compensation gray scale value corresponding to the aging degree of each pixel point, and the digital-to-analog converter 103 converts the compensation gray scale value into the driving voltage of each pixel driving circuit to control the brightness value of each pixel point to be consistent with the brightness value of each pixel point when the pixel point is not aged, so as to realize aging compensation.

It should be noted that the division of each module of the apparatus shown in fig. 1 is only a logical division, and all or part of the actual implementation may be integrated into one physical entity or may be physically separated. And these modules can all be implemented in the form of software invoked by a processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of calling by the processing element through software, and part of the modules can be realized in the form of hardware. For example, the first Gamma corrector 102 may be a separate processing element, or may be implemented by being integrated into a chip of the apparatus, or may be stored in a memory of the apparatus in the form of a program, and a certain processing element of the apparatus calls and executes the function of the first Gamma corrector 102. Other modules are implemented similarly. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element may here be an integrated circuit with signal processing capabilities. In implementation, the steps of the method or the units above may be implemented by hardware integrated logic circuits in a processor element or instructions in software.

The device for screen brightness provided by the embodiment of the application comprehensively considers Demura, Gamma correction and screen burning compensation, can effectively eliminate the Mura phenomenon, solve the aging problem of the screen and realize the Gamma correction on the brightness displayed by the screen, so that the brightness of the image displayed by the screen is consistent with the original brightness of the original input image.

How the various components in the device 10 perform their respective functions is described in detail below.

How the second Gamma corrector 105 determines the initial brightness value of the target pixel point in the screen corresponding to the current shift position is described below.

Alternatively, the screen may have a plurality of different positions for adjusting brightness, the range of brightness values displayable by the screen at different positions for adjusting brightness is different, the position for adjusting brightness of the screen is illustrated below, the maximum brightness value that the screen itself can display is 500nit (nit), if the screen has 5 positions for adjusting brightness, the first position for adjusting brightness is 0-100nit, the range of brightness values displayable by the screen at the second position for adjusting brightness is 0-200nit, …, the range of brightness values displayable by the screen at the fifth position for adjusting brightness is 0-500nit, correspondingly, the 5 positions for adjusting brightness of the screen may correspond to 5 scales on the brightness bar of the screen, for example, the rightmost scale on the brightness bar of the screen corresponds to the fifth position for adjusting brightness, and moving a scale to the left corresponds to a fourth brightness adjustment gear, and so on, wherein the scale on the leftmost side of the screen brightness bar corresponds to the first brightness adjustment gear (namely, the displayable brightness range is minimum, and the brightness of the screen is darkest). Corresponding to different gears for adjusting brightness, when the original image of the screen displays a fixed light-dark relation, the brightness value corresponding to the area with the same brightness degree will also change accordingly. It should be understood that the above listed data are only examples of the shift position of the brightness adjustment of the screen, and do not limit the shift position of the brightness adjustment of the screen and the range of the corresponding displayable brightness values.

Because the image is displayed by means of the relative light and shade relation formed between the pixel points in the screen, when the shift of the screen brightness adjustment is different, the same light and shade proportion can still be kept between the pixel points on the screen based on the same display image, so that the whole display image can keep the original picture characteristics such as textures and patterns when the reference brightness value is changed. Specifically, when the shift of the brightness adjustment of the screen is changed, the brightness value displayed by each pixel point at the shift also changes along with the change of the shift. In an optional situation, positive correlation exists between the shift of the brightness adjustment of the screen and the brightness value displayed by each pixel point, so that the image can be subjected to overall brightness adjustment without damaging the details of the image, such as the pattern, the texture and the like. Therefore, when the brightness is adjusted to the current gear, the initial brightness value corresponding to each pixel point of the screen under the current gear can be determined. Optionally, the device 10 may store a correspondence between the gray scale value and the brightness value in at least one gear, and may determine a correspondence between the gray scale value and the brightness value in other gears according to the correspondence between the gray scale value and the brightness value in the gear; the second Gamma corrector 105 may determine, according to the correspondence between the gray level value and the luminance value at the current shift (i.e., the first Gamma correction table), the luminance value corresponding to the gray level value of each pixel point in the input image at the current shift. Since the mura corrector is not related to brightness adjustment, and the first gamma corrector uses a gamma correction table at a designated gear, i.e., a gamma correction table that is fixed and invariant. When the display brightness of the screen is adjusted to be bright or dark, the mura compensation table in the mura corrector and the second Gamma correction table corresponding to the first Gamma corrector do not need to be replaced, and the corresponding relation between the gray value and the brightness value of the second Gamma corrector 105, namely the first Gamma correction table, only needs to be replaced.

Because each pixel point on the screen is mutually independent, the brightness value of each pixel point is also mutually independent and can only change along with the change of the gear of the brightness adjustment of the screen. Therefore, when the screen is in a certain brightness adjustment gear, for example, the current brightness adjustment gear, each pixel point on the screen has an independent initial brightness value, and when the screen displays different images, the brightness values displayed by each pixel point may be the same or different. Specifically, when the same image is displayed, if the shift of the screen brightness adjustment is adjusted, the brightness value displayed when the gray scale value input by the screen is the maximum can be determined first, and the display brightness value adjusted along with the display of other gray scale values by each pixel point can be determined according to a specific proportion or other positive correlation. It is easy to understand that the initial brightness value displayed by each pixel point and the shift of the brightness adjustment of the screen can be in a positive correlation relationship, that is, the initial brightness value can change in the same direction along with the change of the shift of the brightness adjustment of the screen, and when the shift of the screen is changed from the shift representing a darker picture to the shift representing a brighter picture, the initial brightness value of each pixel point is correspondingly large; and when the gear of the brightness adjustment of the screen is changed from the gear of a brighter picture to the gear of a darker picture, the initial brightness value of each pixel point is correspondingly reduced.

It can be understood that the second Gamma corrector 105 can more accurately determine the corresponding brightness value of each pixel point in the screen at the current gear, that is, the brightness value to be displayed of each pixel point.

How the Mura corrector 101 demara the target pixel point to obtain the target brightness value corresponding to the target pixel point is described below.

Because the Mura phenomenon may exist in the screen, when each pixel point on the screen inputs the same gray scale value, some areas or some pixel points may present different brightness output from other pixel points. Therefore, Demura processing is required to enable each pixel point on the screen to correspondingly output the same brightness value when the same gray scale value is input. mura compensation (also referred to as Demura may be based on the brightness value of each pixel determined by the second Gamma corrector 105. the method for performing mura compensation has more types, for example, implementing internal compensation or external compensation, etc.

The register (or memory) associated with the Mura corrector 101 may store at least one Mura compensation table (i.e., Demura data), and each Mura compensation table is used for indicating the brightness compensation values corresponding to the same gray scale value of each pixel point on the screen. It can be understood that each gray level corresponds to a Mura compensation table, and the Mura corrector 101 may store the Mura compensation tables corresponding to the gray levels; or storing a mura compensation table corresponding to a part of gray-scale values, and determining the mura compensation table corresponding to each gray-scale value according to the mura compensation table corresponding to the part of gray-scale values. For example, when the screen is 8-bit (8bit) gray scale input, 256 gray scale values that can be displayed on the screen are any integer within the interval of 0-255, the register associated with the Mura corrector 101 may store 10 Mura compensation tables corresponding to different gray scale values, and the Mura corrector 101 may obtain another 246 gray scale value corresponding Mura compensation tables according to the 10 gray scale value corresponding Mura compensation tables by using an interpolation method. The Mura corrector 101 may perform Demura on each pixel point in the screen in the same manner. Taking a target pixel point as an example, the Mura corrector 101 may obtain a gray level value corresponding to a brightness value (initial brightness value) to be displayed of the target pixel point, and obtain a brightness compensation value corresponding to the gray level value in a Mura compensation table corresponding to the gray level value; and taking the sum of the initial brightness value and the brightness compensation value as a target brightness value, namely a mura compensated brightness value.

In practical applications, the Demura data (also called compensation data) can be determined as follows: and providing a driving voltage corresponding to a certain gray scale value for a pixel driving circuit corresponding to each pixel point on the screen, and shooting the screen by using equipment such as a high-power camera to obtain the actual brightness value of each pixel point on the screen. If the screen has the Mura phenomenon, the brightness of the pixel points in the region where the Mura phenomenon occurs is different from the brightness of the pixel points outside the region. In this way, the data captured by the camera can be analyzed to obtain compensation data, such as a Mura compensation table. Optionally, the compensation data may include coordinates of the pixels to be compensated in the screen and a brightness compensation value corresponding to each pixel to be compensated. Optionally, the Mura compensation table may include luminance compensation data of each pixel on the screen, and the compensation data of a pixel that does not need to be compensated for normal luminance display is 0. The Mura corrector 101 may be configured to perform Demura on each pixel point in the screen to adjust the brightness value of each pixel point. Optionally, the Mura corrector 101 may perform Demura on each pixel point by using pre-stored Demura data to eliminate a Mura phenomenon in the screen. Therefore, after the step of Demura, the Mura phenomenon of the screen can be compensated, so that each pixel point of the screen has uniform brightness.

How the first Gamma corrector 102 determines the input gray level value corresponding to the target luminance value based on the preset second Gamma correction table will be described.

The preset second Gamma correction table represents the corresponding relation between the output brightness value displayed by the screen and the input gray scale value of the screen. When the screen is displaying, when a certain gray scale value is input to the pixel point, the gray scale value is converted into an analog signal through the DAC103 to control the driving voltage and further control the display brightness value of the pixel point, so that an image is normally displayed on the screen. When the screen is displaying, because of the sensitivity of human eyes or the photoelectric characteristics of the screen itself, a distortion phenomenon may occur between an image output by the screen and an input image, for example, a difference between a color displayed on the screen and an input image is large or a difference between a luminance displayed on the screen and an original luminance of the input image exists. In order to avoid the deviation between the brightness value displayed on the screen and the brightness value of the original image, the gray scale value input by the screen needs to be corrected. Alternatively, the voltage input to the screen may be corrected so that the brightness value of the image displayed on the screen is equal to or linearly related to the brightness value of the image actually input. Under the condition that the screen is in a certain brightness adjusting gear, the Gamma correction relation between the brightness value displayed by any pixel point in the screen and the input gray-scale value can be continuous or discrete. For example, in a certain brightness adjustment gear of the screen, the corresponding relationship between the brightness value displayed by any pixel and the input gray scale value follows the same response curve, i.e., the Gamma curve. At this time, the Gamma curve can be used to represent the corresponding relationship between the luminance value displayed by the pixel point and the input gray scale value under the shift, so as to form the Gamma correction relationship between the luminance value and the input gray scale value. For example, the abscissa of the Gamma curve may represent an input gray-scale value, and the ordinate of the Gamma curve may represent a displayed luminance value. At this time, no matter which brightness is displayed by the pixel point, the corresponding input gray scale value can be found on the Gamma curve. Therefore, the brightness value displayed by the pixel point and the corresponding input gray scale value are continuous and uninterrupted, and when the corresponding input gray scale value is required to be obtained according to the brightness value displayed by the pixel point, the corresponding accurate input gray scale value can be found.

Optionally, the second Gamma correction table may include a plurality of discrete gray scale values and a plurality of display luminance values, the number of gray scale values is equal to the number of display luminance values, the gray scale values correspond to the display luminance values one to one, and the number of discrete gray scale values is equal to the total order of the gray scale values of the screen. Or, the second Gamma correction table may also include a plurality of discrete gray-scale values and a plurality of display luminance values, where the number of gray-scale values is equal to the number of display luminance values, the gray-scale values correspond to the display luminance values one to one, and the number of discrete gray-scale values is less than the total number of gray-scale values of the screen. Optionally, the two-dimensional coordinate points formed by the discrete gray scale values and the display luminance values corresponding to any one of the discrete gray scale values are located on a Gamma curve, where an abscissa of the Gamma curve represents the gray scale value and an ordinate of the Gamma curve represents the display luminance value. Optionally, the current brightness value of the screen at the current gear and the previous brightness value of the previous gear for brightness adjustment satisfy a preset condition, where the current brightness value corresponds to the same input gray scale value as the previous brightness value, and the preset condition is: the ratio of the brightness value difference of the adjacent gears to the previous brightness value satisfies the weber law. The luminance value difference is a difference between a current luminance value and a previous luminance value.

Optionally, the correspondence between the plurality of gray-scale values in the second Gamma correction table and the plurality of display luminance values conforms to a Gamma correction formula, where the display luminance value is an input of the Gamma correction formula, and the gray-scale value is an output of the Gamma correction formula.

Optionally, when the target brightness value at the current gear of the brightness adjustment is not included in the second Gamma correction table, the first Gamma corrector 102 is further configured to obtain a display brightness value closest to the target brightness value in the second Gamma correction table; and then taking the gray scale value corresponding to the display brightness value closest to the target brightness value as the input gray scale value corresponding to the target brightness value.

Optionally, when the target brightness value at the current shift of brightness adjustment is not included in the second Gamma correction table, the first Gamma corrector 102 is specifically configured to determine two display brightness values directly adjacent to the target brightness value at the current shift of brightness adjustment based on the second Gamma correction table; establishing a linear interpolation equation based on two directly adjacent display brightness values and corresponding gray-scale values; and finally, acquiring an input gray level value corresponding to the target brightness value according to the linear interpolation equation and the target brightness value under the current gear of brightness adjustment.

How the dac103 obtains the initial driving voltage according to the input gray scale value is described below.

And the brightness value of the target pixel point is not the target brightness value when the driving voltage of the target pixel driving circuit is the initial driving voltage because the light emitting diode corresponding to the target pixel point is aged. The initial driving voltage is a driving voltage which enables the brightness value of the target pixel point to be the target brightness value before the light emitting diode corresponding to the target pixel point is not aged. That is, if the led corresponding to the target pixel point is not aged, the luminance value of the target pixel point is the target luminance value when the driving voltage of the target pixel driving circuit is the initial driving voltage. The non-aging of the led means that the physical properties of the led are not changed, i.e. the physical parameters of the led, such as the resistance, are not changed. For example, the driving voltage of the pixel driving circuit of a certain led is 11V, the voltage across the led before the led ages is 1V, and the voltage across the led gradually changes with the aging of the led, for example, the voltage across the led after a period of time is 2V.

The digital-to-analog converter 103 can be used to generate a corresponding driving voltage from the input gray scale value. The digital-to-analog converter is used for converting the input gray scale value into an analog driving voltage, so that each pixel driving circuit can enable each pixel point in the screen to display a corresponding brightness value under the action of the driving voltage. Specifically, the digital-to-analog converter can change an input gray-scale value into an actual driving voltage after receiving the input gray-scale value as a digital signal. When the input gray-scale values are different, the corresponding driving voltages are changed accordingly, so that the screen can display different brightness values under different driving voltages and currents to display an actual image. The device 10 may store a corresponding relationship between the input gray level value and the driving voltage; the digital-to-analog converter 103 can generate the driving voltage corresponding to each input gray scale value by using the correspondence relationship. For example, when the screen is 8-bit (8-bit) gray scale input, the number of gray scale values that can be displayed on the screen is 256 in total in any integer within the interval of 0-255, and the digital-to-analog converter 103 can generate a driving voltage corresponding to any gray scale value and provide the driving voltage to the pixel driving circuit. It is understood that each gray level corresponds to a driving voltage, and the driving voltages provided by the dac103 are ranged, i.e. all are in a target interval, for example, an interval greater than 2V and smaller than 12V.

The following describes how the screen burning compensation module 104 obtains the target gray scale value or the reference gray scale value when the brightness value displayed by the target pixel point at the current time is not consistent with the target brightness value.

The brightness displayed by the unaged target pixel point under the driving of the initial driving voltage is equal to the target brightness value; and the brightness displayed by the aged target pixel point under the driving of the initial driving voltage is not equal to the target brightness value. The target gray scale value is the gray scale value when the aged target pixel point displays the target brightness value. Since the led corresponding to the target pixel point is aged (i.e., the target pixel point is aged), the burn-in compensation module 104 needs to obtain the aging compensation data (i.e., the target gray scale value) for making the brightness value of the target pixel point be the target brightness value.

The burn-in compensation module 104 compensates the aged pixel points, so that the actual displayed brightness values of the aged pixel points are the same as the corresponding theoretical brightness values of the aged pixel points in the image source. For the unaged pixels, the burn-in compensation module 104 does not perform aging compensation (i.e., burn-in compensation) on the pixels. However, the aging compensation capability of the burn-in compensation module 104 is limited, and the burn-in compensation module 104 may not make the actual displayed brightness values of the pixels the same as the corresponding theoretical brightness values of the pixels in the image source by performing burn-in compensation on the pixels with the serious aging degree. The reason why the burn-in compensation capability of the burn-in compensation module 104 is limited is that the digital-to-analog converter 103 can convert only input gray scale values smaller than the limit gray scale value into the driving voltage. When the target gray scale value of a certain aged pixel point determined by the burn-in compensation module 104 is greater than the limit gray scale value, the burn-in compensation module 104 performs burn-in compensation on the pixel point, and the actual displayed brightness value of the pixel point cannot be made to be the same as the theoretical brightness value of the pixel point in the image source. The limit gray scale value is positively correlated with the maximum gray scale value which can be displayed by the screen. For example, when the screen is 8-bit (8-bit) gray scale input, the gray scale value that the screen can display is 0-255, and the limit gray scale value can be 255, 256, 257, 258, etc. It should be understood that, as the usage time goes on, physical characteristics of the light emitting diode corresponding to the pixel point may change, for example, a current flowing through the light emitting diode, a voltage across the light emitting diode, a source voltage or a drain voltage of a pixel driving circuit in which the light emitting diode is located, and the like all change.

The screen burning compensation module 104 is specifically configured to determine the target gray scale value or the reference gray scale value based on a screen burning compensation lookup table, where the screen burning compensation lookup table is used to represent a corresponding relationship between an aging degree of the light emitting diode corresponding to the pixel point and the gray scale compensation value. Optionally, the screen-burning compensation module 104 is specifically configured to obtain the target gray-scale value when the aging degree of the light emitting diode corresponding to the target pixel point meets a preset condition, so that the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray-scale value; and when the aging degree of the light-emitting diode corresponding to the target pixel point does not meet a preset condition, acquiring the reference gray-scale value, so that the digital-to-analog converter controls the display brightness of the reference pixel point according to the reference gray-scale value. The preset condition may be that the target gray scale value is not greater than the limit gray scale value.

The burn-in compensation module 104 may send the target gray scale value to the digital-to-analog converter 103 when the target gray scale value is not greater than the limit gray scale value; the digital-to-analog converter 103 controls the display brightness of the target pixel point according to the target gray-scale value. The screen burning compensation module 104 may obtain a reference gray scale value of a reference pixel point when the target gray scale value is greater than the limit gray scale value, and send the reference gray scale value to the digital-to-analog converter 103; the digital-to-analog converter 103 controls the display brightness of the reference pixel point according to the reference gray-scale value. That is to say, when the screen burning compensation module 104 performs screen burning compensation on the target pixel point and cannot enable the target pixel point to display the target brightness value, the screen burning compensation is performed on the pixel points except the target pixel point in the screen, so that the brightness values of the pixel points in the screen are reduced in equal proportion or the brightness values of the pixel points are uniform. For example, the actual displayed brightness value of the target pixel point is reduced by five percent compared with the theoretical brightness value corresponding to the image source, and when the burn-in compensation module 104 performs burn-in compensation on the target pixel point and cannot enable the target pixel point to display the theoretical brightness value, the burn-in compensation module 104 performs burn-in compensation on the pixel points except the aged target pixel point in the screen, so that the brightness value displayed by each pixel point in the screen is reduced by five percent compared with the theoretical brightness value corresponding to the image source.

To describe how the burn-in compensation module 104 obtains the target gray scale value, an embodiment of the present application provides another schematic structural diagram of the apparatus, as shown in fig. 2. The apparatus in fig. 2 is added with a screen 201, a detection circuit 202, and an Application Processor (AP) 203 on the basis of fig. 1. Each pixel point in the screen 201 may display a corresponding brightness value under the control of the dac103, for example, a target pixel point displays a target brightness value.

In an optional implementation manner, the detection circuit 202 is configured to obtain a feedback voltage of a target pixel driving circuit of the target pixel, where the target pixel driving circuit includes the light emitting diode and a driving tube, and the feedback voltage is related to an aging degree of the light emitting diode corresponding to the target pixel point;

and the application processor 203 is used for determining the burn-in compensation lookup table according to the feedback voltage and a pre-stored characteristic curve table, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light emitting diode when the voltage between the gate electrode and the source electrode of the driving tube is fixed and unchanged. The pre-stored characteristic curve table includes: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is in a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

In an optional implementation manner, the detection circuit 202 is configured to obtain a feedback voltage of a target pixel driving circuit of the target pixel point, where the target pixel driving circuit includes a light emitting diode, and the feedback voltage is related to an aging degree of the light emitting diode corresponding to the target pixel point;

an application processor 203, configured to determine the target gray scale value or the reference gray scale value according to the feedback voltage and a pre-stored characteristic curve table, and store the target gray scale value or the reference gray scale value in a memory, where the characteristic curve table is used to represent a corresponding relationship between a voltage between a drain and a source of the driving tube and a current in the light emitting diode when the light emitting diode is at a specified aging degree, and is used to represent a corresponding relationship between a voltage between a drain and a source of the driving tube and a current in the light emitting diode when the voltage between the gate and the source of the driving tube is fixed;

the screen-burning compensation module 104 is specifically configured to obtain the target gray-scale value or the reference gray-scale value from the memory.

In practical applications, the application processor 203 may determine the two compensation gray-scale values in sequence, so as to obtain a target gray-scale value that enables the target pixel point to display the target brightness value. Specifically, the application processor 203 is specifically configured to determine a first compensation value according to the feedback voltage and the pre-stored characteristic curve table; the digital-to-analog converter 103 is further configured to obtain an intermediate driving voltage according to the first compensation value, where the intermediate driving voltage is used to control the target pixel driving circuit; the application processor 203 is specifically configured to determine the target gray scale value according to the intermediate driving voltage and the pre-stored graph of the photoelectric characteristic curve.

In practical application, the screen burning compensation module 104 may perform one-time screen burning compensation or multiple screen burning compensation on the aged pixel points, so that the actual displayed brightness values of the aged pixel points are the same as the corresponding theoretical brightness values of the aged pixel points in the image source. The manner in which the application processor 203 determines the target gray scale value based on the feedback voltage and the pre-stored characteristic curve table is described in detail below.

In an optional manner, the application processor 203 is specifically configured to determine a target aging compensation corresponding relationship from the pre-stored characteristic curve table according to the feedback voltage, where the target aging compensation corresponding relationship represents a corresponding relationship between a voltage between a drain and a source of the driving tube and a current of the light emitting diode when the light emitting diode corresponding to the target pixel point is at the aging degree of the current time;

determining a first reference point according to the target aging compensation corresponding relation, wherein the current of the light emitting diode corresponding to the first reference point is theoretical current, the theoretical current is the current in the light emitting diode when the target pixel point displays the theoretical brightness value, and the theoretical current in the target aging compensation corresponding relation corresponds to reference voltage;

determining a target photoelectric characteristic corresponding relation according to the first reference point, wherein the theoretical current in the target photoelectric characteristic corresponding relation corresponds to the reference voltage;

determining the voltage between the drain electrode and the source electrode of the driving tube corresponding to the target photoelectric characteristic corresponding relation as a first target voltage;

and determining the target gray-scale value of the current moment according to the first target voltage.

The process of determining the target gray scale value by the application processor 203 is described below with reference to the drawings. Fig. 3 is a schematic diagram of a target aging compensation curve and a target optical-electrical characteristic curve according to an embodiment of the present disclosure. As shown in fig. 3, 301 is a target aging compensation curve, 302 is a target photoelectric characteristic curve, and Y denotes a first reference point. The application processor 203 may first determine a target aging compensation curve 301 from the feedback voltage; then, determining a first reference point Y corresponding to the theoretical current in the target aging compensation curve; determining a target photoelectric characteristic curve 302 according to a first reference point Y, and taking the voltage between the drain and the source of the first driving tube corresponding to the target photoelectric characteristic curve 302 as a first target voltage; and determining the burn-in compensation driving voltage at the first moment according to the first target voltage, and determining a target gray-scale value according to the burn-in compensation driving voltage. The way of determining the target aging compensation curve according to the feedback voltage and determining the burn-in compensation driving voltage at the first time according to the first target voltage will be described in detail later, and will not be described in detail first.

Each pixel point in the screen 201 corresponds to a pixel driving circuit, and each pixel point corresponds to a light emitting diode. In practical applications, there are a variety of pixel driving circuits. The pixel driving circuits corresponding to the pixel points are different, and the manner in which the application processor 203 determines the target gray-scale value is also different.

How the application processor 203 obtains the burn-in compensation driving voltage from the feedback voltage is described below with two pixel driving circuits as examples.

Since each pixel point in the screen corresponds to a pixel driving circuit, how the application processor 203 determines the burn-in compensation driving voltage will be described below by taking a pixel driving circuit as an example. Fig. 4 is a schematic structural diagram of an aging compensation circuit according to an embodiment of the present application, where the aging compensation circuit is a part of the apparatus 10 related to burn-in compensation. The target pixel driving circuit in fig. 4 is a pixel driving circuit corresponding to the target pixel point in the screen. As shown in fig. 4, the target pixel driving circuit includes a first driving tube 401 and a first light emitting diode 402 corresponding to the target pixel point, the initial driving voltage provided by the dac103 is the input voltage of the gate of the first driving tube 401, and the drain of the first driving tube 401 inputs a fixed voltage (e.g. a power voltage V) _DD ) The source of the first driving transistor 401 is connected to one end of the first light emitting diode 402, and the other end of the first light emitting diode 402 is grounded or has a negative voltage. The first driving Transistor 401 may be an N-type Thin Film Transistor (TFT), also referred to as an N-type TFT driving Transistor. The target pixel driving circuit in fig. 4 is a simplified pixel driving circuit. In practical applications, the pixel driving circuit may further include a storage capacitor and other devices. The detection circuit 202 of FIG. 4 is used to detect the voltage across the first LED 402, i.e. the targetThe feedback voltage of the pixel driving circuit. Optionally, one end of the first light emitting diode 402 is Grounded (GND), and the voltage detected by the detection circuit at the two ends of the first light emitting diode 402 is the voltage of the source of the first driving transistor. Optionally, one end of the first light emitting diode 402 is connected to a negative voltage, and a sum of the voltage across the first light emitting diode 402 detected by the detection circuit and the negative voltage is a voltage of the source of the first driving transistor. It will be appreciated that the application processor 203 may determine the voltage of the source of the first drive transistor (i.e. the source voltage) from the feedback voltage of the target pixel drive circuit. In FIG. 4, V _D Denotes the drain voltage, V _S Representing the source voltage, V _G Denotes the gate voltage, I _DS Representing the current in the first light emitting diode 402. Since the driving voltage of the gate of the first driving transistor 401 is the initial driving voltage, the drain of the first driving transistor 401 is a fixed voltage. After the application processor 203 obtains the feedback voltage of the target pixel driving circuit, the source voltage V of the first driving tube _S Gate voltage V _G Drain voltage V _D Can be determined, and thus the drain-source voltage V between the drain and the source of the first driving transistor 401 can be determined _DS And a gate-source voltage V between the gate and source of the first drive transistor 401 _GS 。V _DS Is the drain voltage V _D And source voltage V _S Difference, gate source voltage V _GS Is a gate voltage V _G And source voltage V _S The difference between them. The process by which the application processor 203 determines the burn-in compensation drive voltage based on the feedback voltage is described in more detail below.

In an alternative implementation, the application processor 203 may determine a target gray-scale value that compensates the initial driving voltage to the burn-in compensated driving voltage as follows:

the application processor 203 is specifically configured to determine the first source voltage V of the first driving transistor 401 at the first time (i.e. the current time) according to the feedback voltage _S (i.e., the voltage of the source of the first driving transistor 401), where the first source voltage is related to the current aging degree of the target pixel point; the first source voltage V _S Is the feedback voltage and one of the first light emitting diodes 402The sum of the end-connected voltages, one end of the first light emitting diode 402 is connected to a known fixed voltage;

according to the first V _S Determining the first gate-source voltage V of the first driving transistor 401 at the first moment _GS And the first V _GS A corresponding first photoelectric characteristic curve for representing the gate-source voltage V of the first driving tube _GS When the voltage is fixed, the voltage V between the drain electrode and the source electrode of the first driving tube _DS Current I to the first light emitting diode _DS The corresponding relationship of (a);

according to a first V _S Determining a first drain-source voltage V of the first driving tube at the first moment _DS (ii) a The drain of the first driving transistor 401 is a known fixed voltage;

determining the first V in the first photoelectric characteristic curve _DS A corresponding first aging point;

determining a first aging compensation curve according to the first aging point, wherein the first aging compensation curve is related to the aging degree of the target pixel point at the first moment, and the first aging compensation curve represents the drain-source voltage V of the first driving tube when the target pixel point is at the aging degree of the first moment _DS Current I to the first LED _DS The corresponding relationship of (a);

according to theory I _DS Determining a first reference point in the first aging compensation curve, wherein the theoretical IDS is the current in the first light-emitting diode when the target pixel point displays a theoretical brightness value;

determining a second photoelectric characteristic curve containing the first reference point;

determining V corresponding to the second photoelectric characteristic curve _GS Is a first target voltage;

according to the first target voltage and the first V _S And determining the burn-in compensation driving voltage at the first moment.

Fig. 5 is a schematic diagram of an optoelectronic characteristic curve and an aging compensation curve according to an embodiment of the present disclosure. As shown in FIG. 5, 501 is an initial aging compensation curve, i.e. V when the first LED is not aged _DS And I _DS The corresponding curve of (a); 502 is V after the first LED is aged for a period of time _DS And I _DS I.e. the first aging compensation curve; 503 to 506 in the order of V _GS V at 10.3V, 10V, 9V and 8V _DS And I _DS I.e. the photoelectric characteristic curve. It can be understood that 501 is V before the first LED is not aged _DS And I _DS The corresponding curve of (a); 502 is V after the first LED is aged for a period of time _DS And I _DS The corresponding curve of, i.e. the current V _DS And I _DS The corresponding curve of (a). Specific examples are as follows: in FIG. 4, V _DD Is 15V, V _DD ＝V _D ＝15V，V _G Is 11V, V before aging _S 1V, so V before aging _DS ＝V _D -V _S 15V-1V-14V, V before aging _GS ＝V _G -V _S 11V-1V-10V, the current I before aging is not achieved _DS Is the position of the point A in FIG. 5; after aging for a period of time, V _S Change from 1V to 2V, V after aging _DS ＝V _D -V _S 15V-2V-13V, V after aging _GS ＝V _G -V _S 1V-2V-9V, the current after aging is I from the a point position in fig. 5 _DS Changing to position I of B point _DS ；I _DS The current becomes small and the brightness of the first light emitting diode becomes dark because the brightness of the first light emitting diode is proportional to the magnitude of the current. Due to V _G Is a driving voltage generated by the DAC according to the gray scale values of the pixels, so V _G May be varied. Therefore, the input gray scale value sent to the digital-to-analog converter can be adjusted to adjust the driving voltage of the pixel point, the current flowing through the pixel point is adjusted by changing the driving voltage, and the current flowing through the pixel point is positively correlated with the display brightness of the pixel point.

The operations performed by the application processor 203 can be understood in conjunction with fig. 5 to include: the method comprises the steps of determining a position of a point B (namely a first aging point) in a first photoelectric characteristic curve (505 in fig. 5), determining a first aging compensation curve (502 in fig. 5) according to the position of the point B, determining a position of a point D (namely a first reference point) in the first aging curve, determining a second photoelectric characteristic curve (503 in fig. 5) according to the position of the point D, and finally determining a burn-in compensation driving voltage.

In this implementation manner, the application processor 203 determines the burn-in compensation driving voltage quickly and accurately according to the feedback voltage, so as to adjust the brightness value of the target pixel point to the target brightness value, and the operation is simple.

In an alternative implementation, the application processor 203 may first determine a first compensation value, which compensates the initial driving voltage to an intermediate driving voltage; and then determining a second compensation value, wherein the second compensation value compensates the intermediate driving voltage to a second driving voltage, and the specific implementation mode is as follows:

the application processor 203 is specifically configured to determine the first source voltage V of the first driving transistor 401 at the first time (i.e. the current time) according to the feedback voltage _S (i.e., the voltage of the source of the first driving transistor 401), where the first source voltage is related to the current aging degree of the target pixel point; the first source voltage V _S The feedback voltage is the sum of the voltage connected to one end of the first led 402, one end of the first led 402 is connected to a known fixed voltage;

according to the first V _S Obtaining a first compensation voltage by the difference between the first compensation voltage and an initial voltage, where the initial voltage is a voltage across the first light-emitting diode 402 when the target pixel displays a target brightness value when the first light-emitting diode 402 is not aged, and any driving voltage of the target pixel driving circuit corresponds to a voltage across one first light-emitting diode 402; calculating the sum of the first compensation voltage and the initial driving voltage to obtain an intermediate driving voltage; sending a first compensation value corresponding to the intermediate driving voltage to the digital-to-analog converter 103;

the digital-to-analog converter 103 is further used for obtaining an intermediate driving voltage according to the first compensation value; the intermediate driving voltage is used for controlling a target pixel driving circuit;

the detection circuit 202 is further configured to obtain a target feedback voltage of the target pixel driving circuit under the driving of the intermediate driving voltage;

the application processor 203 is specifically configured to determine a burn-in compensation driving voltage according to the target feedback voltage;

and the screen burning compensation module 104 is configured to obtain a second compensation value according to the screen burning compensation driving voltage, and send the second compensation value to the digital-to-analog converter 103.

The digital-to-analog converter 103 is further configured to obtain a burn-in compensation driving voltage according to the second compensation value; the burn-in compensation driving voltage is used for controlling the target pixel driving circuit, so that the brightness value displayed by the aged target pixel point is the target brightness value.

The memory associated with the application processor 203 may store any drive voltage of the target pixel drive circuit corresponding to the voltage across one of the first light emitting diodes 402. For example, when the driving voltage of the target pixel driving circuit is 11V, the voltage across the corresponding first light emitting diode 402 is 1V. That is, the memory associated with the application processor 203 may store V _G V before aging _S The corresponding relationship of (1).

The manner in which the application processor 203 determines the burn-in compensation drive voltage from the target feedback voltage is the same as that of the previous implementation in which the burn-in compensation drive voltage is determined from the feedback voltage.

The application processor 203 can perform screen burning compensation on the aged pixel points only once, namely, the screen burning compensation driving voltage is directly determined according to the feedback voltage; and screen burning compensation can be carried out on the aged pixel points twice or more. Due to the limited storage space of the apparatus 10, the apparatus typically stores only a limited number of photo-electric characteristic curves and aging compensation curves. In practical applications, the device generally needs to be fitted with a plurality of photoelectric characteristic curves to obtain a desired photoelectric characteristic curve, and a plurality of aging compensation curves to obtain a desired aging compensation curve. It can be understood that the accuracy of the photoelectric characteristic curve and the aging compensation curve utilized by the application processor 203 is difficult to guarantee, and the accuracy of the burn-in compensation cannot be guaranteed through one-time burn-in compensation. Therefore, the one-time screen burning compensation mode has the advantages of short time consumption and low compensation precision; the advantage of adopting many times to burn the screen compensation mode is that the compensation precision is high, and the shortcoming is that it takes long time.

The operations performed by the application processor 203 can be understood in conjunction with fig. 5 to include: determining a first compensation value, and transmitting the first compensation value to the digital-to-analog converter 103, the voltage and current in the first light emitting diode at the initial driving voltage corresponding to point B in fig. 5, and the voltage and current in the first light emitting diode at the intermediate driving voltage corresponding to point C in fig. 5; determining the position of a C point in the photoelectric characteristic curve (504 in figure 5), determining a first aging compensation curve (502 in figure 5) according to the position of the C point, determining the position of a D point in the first aging curve, determining a second photoelectric characteristic curve (503 in figure 5) according to the position of the D point, and finally determining the burn-in compensation driving voltage.

In this implementation, the application processor 203 adjusts the driving voltage of the target pixel driving circuit from the initial driving voltage to the intermediate driving voltage, and then adjusts the intermediate driving voltage to the burn-in compensation driving voltage, so that the brightness value of the target pixel point can be accurately adjusted to the target brightness value.

Optionally, a memory associated with the application processor 203 may store a plurality of photoelectric characteristic curves, where each of the plurality of photoelectric characteristic curves represents a corresponding relationship between a voltage between a drain and a source of the first driving tube and a current in the first light emitting diode 402, and voltages between a gate and a source of the first driving tube corresponding to any two photoelectric characteristic curves are different. Optionally, a memory associated with the application processor 203 stores a plurality of photoelectric characteristic curve tables, and each photoelectric characteristic curve table corresponds to one photoelectric characteristic curve. Optionally, the application processor 203 is further configured to obtain the first photoelectric characteristic curve from a plurality of preset photoelectric characteristic curves, or perform fitting by using the plurality of photoelectric characteristic curves to obtain the first photoelectric characteristic curve; the multiple photoelectric characteristic curves represent the corresponding relation between the voltage between the drain electrode and the source electrode of the first driving tube and the current in the first light-emitting diode, and the voltages between the grid electrode and the source electrode of the first driving tube corresponding to any two photoelectric characteristic curves are different. Keeping the voltage between the gate and the source of the first driving transistor constant, measuring the corresponding relationship between the voltage between the drain and the source of the first driving transistor and the current in the first light emitting diode 402 can obtain a photoelectric characteristic curve.

Optionally, a memory associated with the application processor 203 may store a plurality of aging compensation curves, where the aging compensation curves represent a corresponding relationship between a voltage between a drain and a source of the first driving transistor and a current in the first light emitting diode 402, and the aging degrees of the first light emitting diode 402 corresponding to any two aging compensation curves are different. Optionally, a memory associated with the application processor 203 stores a plurality of aging compensation curve tables, and each aging compensation curve table corresponds to one aging compensation curve. The application processor 203 is further configured to obtain the first aging compensation curve from a plurality of aging compensation curves preset, or perform fitting by using at least two aging compensation curves of the plurality of aging compensation curves to obtain the first aging compensation curve.

How the application processor 203 determines the burn-in compensation driving voltage is described below by taking another pixel driving circuit as an example. Fig. 6 is a schematic structural diagram of another aging compensation circuit according to an embodiment of the present disclosure. The pixel driving circuit in fig. 6 is a pixel driving circuit corresponding to a target pixel point in the screen. As shown in fig. 6, the target pixel driving circuit includes a first driving transistor 601 and a first light emitting diode 602 corresponding to the target pixel point, the initial driving voltage provided by the dac103 is the input voltage of the gate of the first driving transistor 601, and the source of the first driving transistor 601 inputs a fixed voltage (e.g. a power voltage V) _DD ) The drain of the first driving transistor 601 is connected to one end of the first light emitting diode 602, and the other end of the first light emitting diode 602 is Grounded (GND) or a negative voltage. The detection circuit 202 in fig. 6 is used to detect the voltage across the first light emitting diode 602, i.e. the feedback voltage of the target pixel driving circuit. Optionally, one end of the first light emitting diode 602 is grounded, and the voltage across the first light emitting diode 602 detected by the detection circuit is used as the voltage of the drain of the first driving transistor 601. Optionally, one end of the first light emitting diode 602 is connected to a negative voltage, and the sum of the voltage across the first light emitting diode 602 detected by the detection circuit and the negative voltage is used as the voltage of the drain of the first driving tube 601. In FIG. 6, V _D Denotes the drain voltage, V _S Represents the source voltage, V _G Denotes the gate voltage, I _SD Representing the current in the first light emitting diode 602. The source and drain positions of the drive transistor of figure 6 are reversed compared to the drive transistor of figure 4. The voltage of the source of the first driving transistor in fig. 4 changes due to the aging of the light emitting diode; since the source of the first driving transistor in fig. 6 is connected to a fixed voltage, the voltage of the first driving transistor does not change. It will be appreciated that if the pixel driving circuit of fig. 6 is used in the device 10, the aging of the light emitting diode will not affect the voltage between the gate and the source of the first driving transistor in the target pixel driving circuit. That is, in the case where the driving voltage of the gate electrode does not change, the voltage between the gate electrode and the source electrode of the driving transistor does not change.

Since the driving voltage of the gate of the first driving transistor 601 is the initial driving voltage, the source of the first driving transistor 601 is a fixed voltage. After the application processor 203 obtains the feedback voltage of the target pixel driving circuit, the source voltage V of the first driving transistor 601 _S Gate voltage V _G Drain voltage V _D Can be determined, so that the drain-source voltage V between the drain and the source of the first driving transistor 601 can be determined _DS And a gate-source voltage V between the gate and source of the first driving transistor 601 _GS 。V _DS Is the drain voltage V _D And source voltage V _S Difference, gate source voltage V _GS Is a gate voltage V _G And source voltage V _S The difference between them. The following illustrates a process of determining the burn-in compensation driving voltage using the aging compensation circuit of fig. 6.

Fig. 7 is a schematic diagram of another optical-electrical characteristic curve and an aging compensation curve according to an embodiment of the present disclosure. As shown in FIG. 7, 701 is an initial aging compensation curve, i.e. V when the first LED is not aged _DS And I _DS The corresponding curve of (a); 702 is V after the first LED is aged for a period of time _DS And I _DS I.e. the third aging compensation curve; 703 denotes V _GS V is 10.3V _DS And I _DS The corresponding curve of (a); 704 denotes V _GS At 10V, V _DS And I _DS The corresponding curve of (a). For example, the first LED 602 is not oldDuring initialization, the voltage and current in the first light emitting diode 602 at the initial driving voltage correspond to point E in fig. 7; after the first light emitting diode 602 is aged for a period of time, the voltage and current in the first light emitting diode 602 at the initial driving voltage correspond to point F in fig. 7. That is, when the driving voltages of the gates of the first driving transistors are the initial driving voltages, the first light emitting diode 602 ages after a period of time, and the current thereof is shown as I from the E point in fig. 7 _DS Changing to position I of F point _DS ；I _DS The current becomes smaller because the brightness of the first light emitting diode becomes dark in proportion to the magnitude of the current. Due to V _G Is a voltage generated by the DAC according to the gray scale values of the pixels, so V _G May be varied. Therefore, the driving voltage provided by the digital-to-analog converter to the pixel current can be adjusted to adjust the current in the first light emitting diode.

In an alternative implementation manner, the application processor 203 may directly adjust the driving voltage of the target pixel driving circuit from the initial driving voltage to the burn-in compensation driving voltage, which is implemented as follows:

the processor 203 is applied, specifically, for determining the second drain voltage V of the first driving transistor 601 at the second time (i.e. the current time) according to the feedback voltage _D (i.e., the voltage of the drain of the first driving transistor 601), the second drain voltage is related to the current aging degree of the target pixel point; the second drain voltage V _D One end of the first light emitting diode 602 is connected to a known fixed voltage, which is the sum of the feedback voltage and the voltage connected to one end of the first light emitting diode 602;

according to the second V _D Determining the second drain-source voltage V of the first driving tube at the second moment _DS (ii) a The source of the first driving transistor 601 is a known fixed voltage;

the second V is determined in the third photoelectric characteristic curve (704 in FIG. 7) _DS A corresponding second aging point (point F in fig. 7); the third photoelectric characteristic curve is the current V _GS Corresponding photoelectric characteristic curve;

according to the second aging pointDetermining a second aging compensation curve (702 in fig. 7), the second aging compensation curve being related to the aging degree of the target pixel point at the second time, the second aging compensation curve representing the drain-source voltage V of the first driving tube when the target pixel point is at the aging degree of the second time _DS Current I to the first LED _DS The corresponding relationship of (a);

according to theory I _DS Determining a second reference point (point H in fig. 7) in the second aging compensation curve, where the theoretical IDS is the current in the first light emitting diode when the target pixel point displays a theoretical luminance value;

determining a fourth photoelectric characteristic curve (703 in fig. 7) including the second reference point;

determining V corresponding to the fourth photoelectric characteristic curve _GS A second target voltage;

according to the second target voltage and the second V _S Determining the burn-in compensation driving voltage at the second moment; the second V _S Is the source voltage of the first driving transistor 601.

The operations performed by the application processor 203 can be understood in conjunction with fig. 7 to include: the F point position (i.e., the second aging point) in the third photoelectric characteristic curve (704 in fig. 7) is determined, the second aging compensation curve (702 in fig. 7) is determined according to the F point position, the H point position (i.e., the second reference point) in the second aging curve is determined, the fourth photoelectric characteristic curve (703 in fig. 7) is determined according to the H point position, and the burn-in compensation driving voltage is determined.

In this implementation manner, the application processor 203 may directly compensate the driving voltage of the target pixel driving circuit from the initial driving voltage to the burn-in compensation driving voltage, so as to adjust the luminance value of the target pixel point to the target luminance value, which is simple to operate and can effectively solve the aging problem of the light emitting diode.

Since the driving voltage provided by the digital-to-analog converter 103 is in a range, the aging compensation of the device 10 has a certain compensation effect limit. When the device 10 confirms that the aging compensation for the aging region has reached the compensation effect limit or is invalid, the aging is corrected by the photoelectric characteristic curveAnd (3) forming the area, reducing the brightness of the unaged area to be close to that of the aged area, and maintaining the gamma2.2 curve. That is, there is no way to adjust the aging area, and this time, the unaged area is adjusted, so that the brightness of the whole screen conforms to the gamma2.2 curve. The aging area refers to an area where a pixel point corresponding to an aged light emitting diode in a screen is located, and the non-aging area refers to an area except the aging area in the screen. For any pixel point, if the target gray scale value of the pixel point determined by the application processor 203 is greater than the limit gray scale value, it is determined that the aging compensation performed on the pixel point has reached the compensation effect limit or is invalid. Fig. 8 is a schematic diagram of another optical-electrical characteristic curve and an aging compensation curve provided in the embodiment of the present application. As shown in FIG. 8, 801 is an initial aging compensation curve, i.e. V when the first LED is not aged _DS And I _DS The corresponding curve of (a); 802 is V after the first LED is aged for a period of time _DS And I _DS The corresponding curve of (a); 803 to 806 represent in turn V _GS V at 10.3V, 10V, 9V and 8.8V _DS And I _DS The corresponding curve of (a). Fig. 9 is a schematic diagram of a pixel point of a screen according to an embodiment of the present application. In fig. 9, the initial currents (proportional to the brightness) of the pixel points 1 to 9 correspond to the position of the point a in fig. 8, the current of the aged pixel point 1 changes from the position of the point a in fig. 8 to the position of the point B after a period of time, and after it is determined that the pixel point 1 cannot return to the position of the point D in fig. 8, the currents of the pixel points 2 to 9 can be corrected by using the photoelectric characteristic curve, that is, the currents of the pixel points 2 to 9 are adjusted from the position of the point a in fig. 8 to the position of the point M, and the currents of the position of the point B are the same as the currents of the position of the point M.

It can be understood that, when the application processor 203 performs the screen burning compensation on the target pixel point and cannot enable the target pixel point to display the target brightness value, the screen burning compensation is performed on the pixel points in the screen except the target pixel point, so that the brightness values of the pixel points in the screen are reduced in equal proportion or the brightness values of the pixel points are uniform.

Taking a target pixel point and a reference pixel point in a screen as an example, a scheme of how to perform screen burning compensation on the reference pixel point under the condition that the brightness value of the target pixel point cannot be controlled as a target brightness value is introduced below. And the aging degree of the first light-emitting diode corresponding to the target pixel point is different from the aging degree of the second light-emitting diode corresponding to the reference pixel point. The application processor 203 may determine a reference gray-scale value of a reference pixel point when the determined target gray-scale value of the target pixel point is greater than a limit gray-scale value, where the reference gray-scale value is used to adjust a brightness value displayed by the reference pixel point. When the corresponding brightness values of the target pixel point and the reference pixel point in the image source are equal, the reference gray-scale value is the gray-scale value when the reference pixel point displays the reference brightness value, and the reference brightness value is equal to the brightness value displayed by the aged target pixel point under the driving of the initial driving voltage of the target pixel driving circuit. When the corresponding brightness values of the target pixel point and the reference pixel point in the image source are not equal, the reference gray-scale value is a gray-scale value when the reference pixel point displays an intermediate brightness value, the ratio of the intermediate brightness value to the theoretical brightness value of the reference pixel point in the image source to be decreased (or increased) is equal to the ratio of the actual brightness value to the theoretical brightness value of the target pixel point in the image source to be decreased (or increased), and the actual brightness value is the brightness value displayed by the aged target pixel point under the driving of the initial driving voltage of the target pixel driving circuit. In practical application, the application processor 203 may determine the brightness value to be displayed of the reference pixel point in different manners, so as to reduce the brightness value of each pixel point in the screen in an equal proportion or make the brightness value of each pixel point uniform after performing screen burning compensation on the reference pixel point. The mode of the application processor 203 for performing the screen burning compensation on the reference pixel point is similar to the mode for performing the screen burning compensation on the target pixel point, and is not described herein again.

In the embodiment of the application, the device solves the problem that an aged pixel point cannot be adjusted to a required brightness value through screen burning compensation by adjusting the driving voltage of the unaged pixel point, and the implementation is simple.

The components of the device are further subdivided below to facilitate a clearer description of the brightness correction process and the burn-in compensation process. Fig. 10 is a schematic structural diagram of another screen brightness apparatus according to an embodiment of the present application. The device of fig. 10 is a further subdivision of the device of fig. 2. As shown in fig. 10, the apparatus 10 further includes an Analog-to-Digital Converter (ADC) 1004, a first memory 1005, and a third memory 1006; the burn-in compensation module 104 includes a burn-in compensation unit 1001 and a second memory 1002. The ADC1004 (i.e., the detection circuit 203) is configured to convert the acquired feedback voltage of the target pixel into a digital signal, and store the digital signal in the first memory 1005. The application processor 203 is configured to obtain a digital signal corresponding to the feedback voltage from the first memory 1005, and determine a burn-in compensation driving voltage of the target pixel according to the feedback voltage. And a second memory 1002 for storing data required by the application processor 203 to determine the burn-in compensation driving voltage according to the feedback voltage, such as a photoelectric characteristic curve, an aging compensation curve, and the like. The second memory 1002 is further configured to store the burn-in compensation driving voltage. And the screen burning compensation unit 1001 is configured to determine a target gray-scale value corresponding to the screen burning compensation driving voltage, and send the target gray-scale value to the DAC 103. A third storage 1006, configured to store a Mura compensation table (i.e., compensation data) required by the Mura corrector 101 for Demura of the pixels in the screen.

The burn-in compensation circuitry of the apparatus 10 associated with burn-in compensation is further detailed below to facilitate a clearer description of the burn-in compensation process. The aging compensation circuit of fig. 11 is a further subdivision of the aging compensation circuit of fig. 10. As shown in fig. 11, the operations implemented by the application processor 203 include: acquiring a digital signal corresponding to a feedback voltage of a target pixel driving circuit, and determining preliminary aging compensation data (namely, an intermediate driving voltage in the foregoing embodiment) of a target pixel point according to the feedback voltage; and correcting the preliminary aging compensation data according to the photoelectric characteristic curve, the aging compensation curve and the preliminary aging compensation data to obtain the burn-in compensation driving voltage. As shown in fig. 11, when the first driving transistor in the target pixel driving circuit is an N-type TFT driving transistor, the burn-in compensation module 104 performs twice burn-in compensation on the aged target pixel. That is, the application processor 203 determines an intermediate driving voltage (i.e., preliminary aging compensation data) from the first feedback voltage of the target pixel driving circuit (the driving voltage is the initial driving voltage); the DAC103 supplies the intermediate drive voltage to the target pixel drive circuit; the application processor 203 determines the burn-in compensation driving voltage according to the second feedback voltage of the target pixel driving circuit (the driving voltage is the intermediate driving voltage), the photoelectric characteristic curve and the aging compensation curve, that is, corrects the preliminary aging compensation data to obtain the burn-in compensation driving voltage.

The modules in the apparatus 10 may be one or more integrated circuits configured to implement the above methods, such as: one or more application-specific integrated circuits (ASICs), or one or more Digital Signal Processors (DSPs), or one or more field-programmable gate arrays (FPGAs), among others. For another example, when some of the above modules are implemented in the form of a processing element scheduler, the processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling programs. As another example, these modules may be integrated together, implemented in the form of a system-on-a-chip (SOC).

Fig. 12 is a flowchart illustrating a method for controlling screen brightness according to an embodiment of the present application, where the method is applied to a device for controlling screen brightness, the device includes a processor, a Mura corrector, a first Gamma corrector, a second Gamma corrector, and a digital-to-analog converter, and the method includes:

1201. and the second Gamma corrector determines the corresponding initial brightness value of the target pixel point under the current gear according to the first Gamma correction table.

The target pixel point is any pixel point in the screen.

1202. And the Mura corrector performs Demura on the initial brightness value of the target pixel point to obtain a target brightness value.

1203. And the first Gamma corrector determines an input gray level value corresponding to the target brightness value according to the second Gamma correction table.

The second Gamma correction table comprises a plurality of groups of Gamma correction relations between the brightness values and the gray-scale values.

1204. The digital-to-analog converter obtains an initial driving voltage according to the input gray-scale value.

The initial driving voltage is used for controlling a target pixel driving circuit so that the brightness displayed by the target pixel point is the target brightness value.

1205. And the processor determines a target gray-scale value when the current display brightness value of the target pixel point is inconsistent with the target brightness value. The brightness displayed by the target pixel point under the drive of the initial drive voltage is not equal to the target brightness value, and the target gray-scale value is the gray-scale value when the target pixel point displays the target brightness value.

1206. And the processor sends the target gray-scale value to the digital-to-analog converter under the condition that the target gray-scale value is not greater than the limit gray-scale value.

Optionally, the apparatus further includes a burn-in compensation module and a memory, the processor stores the target gray-scale value to the burn-in compensation module when determining that the target gray-scale value is not greater than the limit gray-scale value, and the burn-in compensation module obtains the target gray-scale value and sends the target gray-scale value to the digital-to-analog converter.

1207. And the digital-to-analog converter obtains the burn-in compensation driving voltage according to the target gray scale value.

The target pixel driving circuit enables the brightness value displayed by the aged target pixel point to be the target brightness value under the driving of the screen burning compensation driving voltage. The steps in fig. 12 are described in detail in the foregoing embodiments, and are not described in detail here.

When the target pixel point is subjected to screen burning compensation and cannot display the target brightness value, the pixel values of other pixel points can be adjusted. Steps 1206 to 1207 may be replaced with: the processor determines a reference gray-scale value under the condition that the target gray-scale value is greater than the limit gray-scale value, wherein the reference pixel point is a pixel point with different aging degree from that of the target pixel point in the screen, the reference gray-scale value is a gray-scale value for compensating the brightness of the reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen; and the digital-to-analog converter obtains a reference screen burning compensation driving voltage according to the reference gray scale value. The reference pixel driving circuit is driven by the reference screen burning compensation driving voltage, so that the brightness value displayed by the reference pixel point is equal to the brightness value displayed by the aged target pixel point under the driving of the initial driving voltage by the target pixel driving circuit.

Fig. 13 is a schematic hardware structure diagram of a terminal device according to an embodiment of the present application. As shown in fig. 13, the terminal apparatus 1300 includes: the multi-Gamma correction device comprises a Mura corrector 1301, a first Gamma corrector 1302, a digital-to-analog converter 1303, a screen burning compensation module 1304 and a screen 1305.

The Mura corrector 1301 is configured to perform Demura on a target pixel in the screen 1305 to obtain a target brightness value corresponding to the target pixel, where the target brightness value is a theoretical brightness value of the target pixel in an input image source.

The first Gamma corrector 1302 is configured to determine an input gray level value corresponding to the target luminance value.

And the digital-to-analog converter 1303 is configured to obtain an initial driving voltage according to the input gray scale value, where the initial driving voltage is used to control the target pixel driving circuit, so that the brightness displayed by the target pixel point is the target brightness value.

The screen burning compensation module 1304 is configured to, when the brightness value displayed by the target pixel point at the current time is inconsistent with the target brightness value, obtain a target gray scale value or a reference gray scale value, where the target gray scale value is a gray scale value of the target pixel point when the target brightness value is displayed at the current time, the reference gray scale value is a gray scale value of the reference pixel point when the reference brightness value is displayed at the current time, the reference pixel point is a pixel point of which the aging degree in the screen is different from the aging degree of the target pixel point, and the reference brightness value is positively correlated with the brightness value displayed by the target pixel point at the current time.

The digital-to-analog converter 1303 is further configured to control the display brightness of the target pixel point according to the target gray scale value; alternatively, the first and second electrodes may be,

the digital-to-analog converter 1303 is further configured to control the display brightness of the reference pixel point according to the reference gray scale value.

Optionally, the terminal device 1300 further includes:

the second Gamma corrector 1306 is used for determining an initial brightness value corresponding to the target pixel point in the current gear according to the first Gamma correction table;

a Mura corrector 1301, specifically configured to perform Demura on the initial brightness value of the target pixel point to obtain the target brightness value;

a first Gamma corrector 1302, specifically configured to determine the input gray level value corresponding to the target brightness value according to a second Gamma correction table; the second Gamma correction table is a Gamma correction relation between the brightness value of the screen and the input gray level value under the designated gear of brightness adjustment; the first gamma correction table is obtained according to the second gamma correction table.

Optionally, the terminal device 1300 further includes: a detection circuit. The terminal device in this embodiment of the application may execute the brightness control method of the screen in the foregoing embodiment, and the specific processes and steps of the brightness control method of the screen have been described in detail in the foregoing embodiment, and are not described again here. The terminal device in the embodiment of the present application may be the apparatus 10 in the foregoing embodiment, and may also be a device including the apparatus 10, such as a mobile phone.

The first Gamma corrector 1302, the second Gamma corrector 1306 and the burn-in compensation module 1304 may be integrated on the same processor, or may be separate hardware logic or hardware circuits. The Mura corrector 1301 may be integrated on the burn-in compensation module 1304, or may be hardware logic or hardware circuitry independent of the burn-in compensation module 1304. The digital-to-analog converter 1303 may be a separate hardware, such as a driving circuit. The burn-in compensation module 1304 corresponds to the burn-in compensation module 104 or to the burn-in compensation module 104 and the application processor 203 (i.e., the burn-in compensation module 1304 implements the functionality of the burn-in compensation module 104 and the application processor 203). The burn-in compensation module 1304 may be an application processor.

In addition, optionally, the terminal device 1300 may further include a memory 1307, where the memory 1307 is configured to store a preset Gamma correction table and compensation data required by the Mura corrector 1301 for Demura.

The screen 1305 is usually formed by an Organic Light Emitting Display (OLED) or an Active-matrix Organic Light Emitting diode (AMOLED).

Specifically, the digital-to-analog converter 1303 may include a voltage generator and a brightness controller. Wherein the voltage generator is operable to generate a corresponding driving voltage in accordance with the input gray scale value; and the luminance controller may be configured to control the screen to display a display luminance value corresponding to the input gray scale value based on the driving voltage.

Since the input gray scale value is usually a Digital signal, in order to convert the input gray scale value into an analog voltage value, the voltage generator may be a Digital to analog converter (DAC). The digital-to-analog converter is used for converting the input gray-scale value into an analog reference voltage value, so that the brightness controller can control the display brightness value of the screen according to the reference voltage value, and the screen can display the corresponding display brightness value when being electrified. Specifically, the digital-to-analog converter can change an input gray-scale value into an actual voltage value after receiving the input gray-scale value as a digital signal. When the input gray-scale values are different, the corresponding voltage values are changed, so that the screen can emit light rays with different brightness under the excitation of different voltage values and current values to display an actual image.

The burn-in compensation module 1304, the Mura corrector 1301, the first Gamma corrector 1302, the second Gamma corrector 1306, the digital-to-analog converter 1303 and the memory 1307 may use a communication bus or other data paths to transmit data and signals. Because the memory 1307 is electrically connected to the burn-in compensation module 1304, the Mura corrector 1301, and the first Gamma corrector 1302, the preset second Gamma correction table stored in the memory 1307 can be transmitted to the first Gamma corrector 1302, and the compensation data stored in the memory 1307 can be transmitted to the Mura corrector 1301.

The burn-in compensation module 1304 is usually the control center of the terminal device, and can be connected with different hardware parts such as the memory 1307 by using a communication bus, and execute various functions of the terminal device and process data by running or executing software programs and/or modules and calling data stored in the memory, thereby completing the brightness control operation of the screen. The processor 1304 may be a Micro Controller Unit (MCU), or a Central Processing Unit (CPU), or a stand-alone system-on-a-chip (SOC), or one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others.

Optionally, the burn-in compensation module 1304 may include one or more processing units; and different processing units are utilized to respectively execute the different instructions and programs so as to respectively execute different functions.

And memory 1307 may be, but is not limited to, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 1307 may be a separate memory connected to the burn-in compensation module 1304 and the first Gamma correction 1303 via a bus. Memory 1307 may also be integrated with burn-in compensation module 1304.

In addition to storing the preset Gamma correction table, the memory 1307 may also be used to store the application program code for executing the scheme of the present application, and the execution is controlled by the burn-in compensation module 1304. The burn-in compensation module 1304 is used for executing the application program codes stored in the memory 1307, so as to implement the brightness control method of the screen provided by the above-mentioned embodiment of the present application.

In order to cooperate with external devices such as a high power camera, the terminal device may further include an I/O subsystem for connecting the external devices and the terminal device itself. The I/O subsystem may be used to implement data interaction with an external device, thereby implementing input and output of data collected by the external device, and control of a working state of the external device.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in accordance with the embodiments of the application are all or partially generated when the computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or can comprise one or more data storage devices, such as a server, a data center, etc., that can be integrated with the medium. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An apparatus for controlling screen brightness, comprising:

the screen burning compensation module is used for acquiring a target gray-scale value or a reference gray-scale value when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen;

the digital-to-analog converter is used for controlling the display brightness of the target pixel point according to the target gray scale value; alternatively, the first and second electrodes may be,

the digital-to-analog converter is used for controlling the display brightness of the reference pixel point according to the reference gray-scale value;

the burn-in compensation module is specifically configured to determine the target gray scale value or the reference gray scale value based on a burn-in compensation lookup table, the burn-in compensation lookup table is used for representing the corresponding relation between the aging degree of the light emitting diode corresponding to the pixel point and the gray scale compensation value, the burn-in compensation look-up table is determined according to the feedback voltage of the target pixel driving circuit of the target pixel point and the characteristic curve table, the feedback voltage is related to the aging degree of the light-emitting diode corresponding to the target pixel point, the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode is in the specified aging degree, and the driving circuit is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged.

2. The apparatus of claim 1,

the burn-in compensation module is specifically configured to, when the current display brightness value is inconsistent with the target brightness value due to aging of a light emitting diode corresponding to the target pixel point, obtain the target gray level value or the reference gray level value, where the target brightness value is a theoretical brightness value of the target pixel point in an input image source;

the digital-to-analog converter is specifically used for controlling the display brightness of the target pixel point to be the target brightness value according to the target gray scale value; alternatively, the first and second electrodes may be,

the digital-to-analog converter is specifically configured to control the display brightness of the reference pixel point to be a reference brightness value according to the reference gray scale value, where the reference brightness value is positively correlated with the current display brightness value.

3. The apparatus of claim 1,

the screen burning compensation module is specifically configured to obtain the target gray scale value when the aging degree of the light emitting diode corresponding to the target pixel point meets a preset condition, so that the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray scale value;

and when the aging degree of the light emitting diode corresponding to the target pixel point does not meet a preset condition, acquiring the reference gray-scale value so that the digital-to-analog converter controls the display brightness of the reference pixel point according to the reference gray-scale value.

4. The apparatus of any one of claims 1 to 3, further comprising:

the detection circuit is used for acquiring the feedback voltage of a target pixel driving circuit of the target pixel point, and the target pixel driving circuit comprises the light emitting diode and a driving tube;

and the application processor AP is used for determining the burn-in compensation lookup table according to the feedback voltage and the characteristic curve table.

5. The apparatus of claim 4, further comprising:

the first Gamma corrector is used for determining the corresponding initial brightness value of the target pixel point at the current gear of brightness adjustment according to a first Gamma correction table, and the first Gamma correction table is the Gamma correction relation between the display brightness value and the gray level value at the current gear;

the Mura corrector is specifically used for performing uniformity compensation Demura on the initial brightness value of the target pixel point to obtain the target brightness value;

the second Gamma corrector is specifically used for determining an initial gray level value corresponding to the target brightness value according to a preset second Gamma correction table; the second Gamma correction table is used for displaying the Gamma correction relation between the brightness value and the gray value under the designated gear of brightness adjustment, and the first Gamma correction table is obtained according to the second Gamma correction table;

and the digital-to-analog converter is also used for controlling the display brightness of the target pixel point to be the target brightness value according to the initial gray scale value when the corresponding light emitting diode of the target pixel point is not aged.

6. An apparatus for controlling screen brightness, comprising:

the screen burning compensation module is used for acquiring a target gray scale value or a reference gray scale value when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, wherein the target gray scale value is a gray scale value for compensating the brightness of the target pixel point, the reference gray scale value is a gray scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen;

the digital-to-analog converter is used for controlling the display brightness of the target pixel point according to the target gray scale value; alternatively, the first and second liquid crystal display panels may be,

the detection circuit is used for acquiring the feedback voltage of a target pixel driving circuit of the target pixel point, the target pixel driving circuit comprises a light emitting diode, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point;

an application processor AP, configured to determine the target gray scale value or the reference gray scale value according to the feedback voltage and a pre-stored characteristic curve table, and store the target gray scale value or the reference gray scale value in a memory, where the characteristic curve table is used to represent a corresponding relationship between a voltage between a drain and a source of a driving tube and a current in the light emitting diode when the light emitting diode is at a specified aging level, and is used to represent a corresponding relationship between a voltage between the drain and the source and a current in the light emitting diode when the voltage between the gate and the source of the driving tube is fixed;

the screen burning compensation module is specifically configured to obtain the target gray scale value or the reference gray scale value from the memory.

7. The apparatus of claim 6,

the AP is specifically configured to determine a first compensation value according to the feedback voltage and the pre-stored characteristic curve table;

the digital-to-analog converter is further configured to obtain an intermediate driving voltage according to the first compensation value, where the intermediate driving voltage is used to control the target pixel driving circuit;

the AP is specifically configured to determine the target gray scale value according to the intermediate driving voltage and the pre-stored photoelectric characteristic curve table.

8. The apparatus of claim 6, wherein the target pixel drive circuit further comprises a drive tube, and wherein the pre-stored characterization curve table comprises: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is in a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

9. The apparatus of claim 8,

the AP is specifically configured to determine a target aging compensation corresponding relationship from the pre-stored characteristic curve table according to the feedback voltage, where the target aging compensation corresponding relationship represents a corresponding relationship between a voltage between a drain and a source of the driving tube and a current of the light emitting diode when the light emitting diode corresponding to the target pixel point is at an aging degree of a current time;

determining a first reference point according to the target aging compensation corresponding relation, wherein the current of the light emitting diode corresponding to the first reference point is theoretical current, the theoretical current is the current in the light emitting diode when the target pixel point displays a theoretical brightness value, and the theoretical current in the target aging compensation corresponding relation corresponds to reference voltage;

10. The apparatus of any one of claims 6 to 9, further comprising:

the first Gamma corrector is used for determining an initial brightness value corresponding to the target pixel point at the current gear of brightness adjustment according to a first Gamma correction table, and the first Gamma correction table is a Gamma correction relation between a display brightness value and a gray scale value at the current gear;

11. A method for controlling screen brightness, the method comprising:

when a current display brightness value of a target pixel point in a screen is inconsistent with a target brightness value, acquiring a target gray-scale value or a reference gray-scale value, wherein the target gray-scale value is a gray-scale value for compensating the brightness of the target pixel point, the reference gray-scale value is a gray-scale value for compensating the brightness of a reference pixel point, and the reference pixel point is other pixel points except the target pixel point in the screen;

controlling the display brightness of the target pixel point according to the target gray scale value; or, controlling the display brightness of the reference pixel point according to the reference gray-scale value;

the obtaining the target gray-scale value or the reference gray-scale value includes:

determining the target gray-scale value or the reference gray-scale value based on a burn-in compensation lookup table, wherein the burn-in compensation lookup table is used for representing the corresponding relation between the aging degree of the light-emitting diode corresponding to the pixel point and the gray-scale compensation value, the burn-in compensation look-up table is determined according to the feedback voltage of the target pixel driving circuit of the target pixel point and the characteristic curve table, the feedback voltage is related to the aging degree of the light-emitting diode corresponding to the target pixel point, the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode is in the specified aging degree, and the driving circuit is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed and unchanged.

12. The control method according to claim 11, wherein the obtaining the target gray-scale value or the reference gray-scale value includes:

when the current display brightness value is inconsistent with the target brightness value due to aging of the light emitting diode corresponding to the target pixel point, acquiring the target gray level value or the reference gray level value, wherein the target brightness value is a theoretical brightness value of the target pixel point in an input image source;

controlling the display brightness of the target pixel point according to the target gray scale value; or, controlling the display brightness of the reference pixel point according to the reference gray-scale value includes:

controlling the display brightness of the target pixel point to be the target brightness value according to the target gray scale value; or controlling the display brightness of the reference pixel point to be a reference brightness value according to the reference gray-scale value, wherein the reference brightness value is positively correlated with the current display brightness value.

13. The control method according to claim 11, wherein the obtaining the target gray scale value or the reference gray scale value includes:

when the aging degree of the light-emitting diode corresponding to the target pixel point meets a preset condition, acquiring the target gray-scale value, so that the digital-to-analog converter controls the display brightness of the target pixel point according to the target gray-scale value;

and when the aging degree of the light-emitting diode corresponding to the target pixel point does not meet a preset condition, acquiring the reference gray-scale value, so that the digital-to-analog converter controls the display brightness of the reference pixel point according to the reference gray-scale value.

14. The control method of any of claims 11 to 13, wherein prior to determining the target gray scale value or the reference gray scale value based on a burn-in compensation look-up table, the method further comprises:

obtaining a feedback voltage of a target pixel driving circuit of the target pixel point, wherein the target pixel driving circuit comprises the light emitting diode and a driving tube;

and determining the burn-in compensation lookup table according to the feedback voltage and the characteristic curve table.

15. The control method according to any one of claims 11 to 14, wherein before the obtaining of the target gray scale value or the reference gray scale value, the method further comprises:

determining an initial brightness value corresponding to the target pixel point at a current gear of brightness adjustment according to a first Gamma correction table, wherein the first Gamma correction table is a Gamma correction relation between a display brightness value and a gray scale value at the current gear;

performing uniformity compensation Demura on the initial brightness value of the target pixel point to obtain the target brightness value;

determining an initial gray-scale value corresponding to the target brightness value according to a preset second Gamma correction table; the second Gamma correction table is used for displaying the Gamma correction relation between the brightness value and the gray value under the designated gear of brightness adjustment, and the first Gamma correction table is obtained according to the second Gamma correction table;

and when the target pixel point is not aged in the corresponding light emitting diode, controlling the display brightness of the target pixel point to be the target brightness value according to the initial gray scale value.

16. A method for controlling screen brightness, the method comprising:

controlling the display brightness of the target pixel point according to the target gray scale value; or controlling the display brightness of the reference pixel point according to the reference gray-scale value; before the obtaining of the target gray-scale value or the reference gray-scale value, the method further includes:

obtaining a feedback voltage of a target pixel driving circuit of the target pixel point, wherein the target pixel driving circuit comprises a light emitting diode, and the feedback voltage is related to the aging degree of the light emitting diode corresponding to the target pixel point;

determining the target gray-scale value or the reference gray-scale value according to the feedback voltage and a pre-stored characteristic curve table, and storing the target gray-scale value or the reference gray-scale value in a memory, wherein the characteristic curve table is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode is at a specified aging degree, and is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the gate electrode and the source electrode of the driving tube is fixed;

the acquiring of the target gray-scale value or the reference gray-scale value includes:

and acquiring the target gray-scale value or the reference gray-scale value from the memory.

17. The control method according to claim 16, wherein the determining the target gray-scale value or the reference gray-scale value according to the feedback voltage and a pre-stored characteristic curve table includes:

determining a first compensation value according to the feedback voltage and the pre-stored characteristic curve table, so that the digital-to-analog converter obtains an intermediate driving voltage according to the first compensation value, wherein the intermediate driving voltage is used for controlling the target pixel driving circuit;

and determining the target gray-scale value according to the intermediate driving voltage and the pre-stored photoelectric characteristic curve table.

18. The control method according to claim 16, wherein the target pixel drive circuit further includes a drive tube, and the pre-stored characteristic curve table includes: the aging compensation corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current in the light-emitting diode when the light-emitting diode corresponding to the target pixel point is in a specified aging degree, and the photoelectric characteristic corresponding relation is used for representing the corresponding relation between the voltage between the drain electrode and the source electrode and the current in the light-emitting diode when the voltage between the grid electrode and the source electrode of the driving tube is fixed.

19. The control method according to claim 18, wherein the determining the target gray-scale value or the reference gray-scale value according to the feedback voltage and a pre-stored characteristic curve table includes:

determining a target aging compensation corresponding relation from the pre-stored characteristic curve table according to the feedback voltage, wherein the target aging compensation corresponding relation represents the corresponding relation between the voltage between the drain electrode and the source electrode of the driving tube and the current of the light-emitting diode when the light-emitting diode corresponding to the target pixel point is at the aging degree of the current moment;

and determining the target gray-scale value at the current moment according to the first target voltage.

20. The control method according to any one of claims 16 to 19, wherein before the obtaining of the target gray scale value or the reference gray scale value, the method further comprises:

determining an initial gray-scale value corresponding to the target brightness value according to a preset second Gamma correction table; the second Gamma correction table is used for displaying the Gamma correction relation between the brightness value and the gray value under the specified gear of brightness adjustment, and the first Gamma correction table is obtained according to the second Gamma correction table;