Display panel, brightness compensation method thereof and display driving chip

Abstract

The invention provides a display panel, a brightness compensation method thereof and a display driving chip. The problem that in the prior art, the brightness of a display image of the same gray scale is not uniform is solved. The display panel comprises a display area, the display area comprises a plurality of sub-display areas, and the brightness compensation method comprises the following steps: acquiring the voltage drop of the display area, the screen body current of the display area and the resistance of any sub-display area; based on the voltage drop, the screen body current, the resistance of any sub-display area and a preset relation model: Lumn is in direct proportion to (K-I * Rn) 2, determining the actual display brightness of any sub-display area; determining a brightness compensation value of each sub-display area based on the actual display brightness of the sub-display areas; and performing brightness compensation on the sub-display area based on the brightness compensation value. And the phenomenon of excessive brightness compensation is almost avoided.

Description

Technical Field

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

[0002] The voltage division caused by the resistance of the ELVDD metal line in the display panel causes the voltage in the ELVDD metal line to gradually decrease in the direction away from the display driver chip, resulting in uneven ELVDD voltage in the entire display panel, and further resulting in uneven brightness of the same grayscale display screen. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a brightness compensation method for a display panel, which solves the problem of uneven brightness of a display screen with the same grayscale in the prior art.

[0004] In a first aspect, the present application provides a brightness compensation method for a display panel, wherein the display panel includes a display area, the display area includes a plurality of sub-display areas, and the brightness compensation method includes:

[0005] Obtaining the voltage drop of the display area, the screen current of the display area, and the resistance of any sub-display area;

[0006] Based on the preset relationship model Lum n ∝(KI*R n ) 2 , determine the actual display brightness of any sub-display area, where Lum n is the actual display brightness of the nth sub-display area, R n is the resistance of the nth sub-display area, I is the screen current, K is the voltage drop, n is the number of sub-display areas, and n is an integer greater than or equal to 1;

[0007] Determining a brightness compensation value for each sub-display area based on an actual display brightness of the sub-display area;

[0008] The sub display area is brightness compensated based on the brightness compensation value.

[0009] In one embodiment, the step of obtaining the voltage drop of the display area, the screen current of the display area, and the resistance of any sub-display area includes:

[0010] Obtaining a target display brightness of a predetermined area of ​​the display area when displaying in full grayscale, a voltage drop of the display area, a screen current of the display area, and a resistance of any sub-display area;

[0011] Preferably, based on the preset relationship model Lum n ∝(KI*R n ) 2 The step of determining the actual display brightness of any sub-display area includes:

[0012] Based on the target display brightness, voltage drop, screen current, resistance of any sub-display area, and the preset relationship model: Lum n / L1=(KI*R n ) 2 / K 2 , determine the actual display brightness of any sub-display area, where L1 is the target display brightness;

[0013] Preferably, the step of obtaining the target display brightness of a predetermined area of ​​the display area when the full grayscale is displayed includes:

[0014] Obtaining the brightness of the center position of the display area when displaying in full grayscale as the target display brightness;

[0015] Preferably, determining the brightness compensation value of each sub-display area based on the actual display brightness of the sub-display area includes:

[0016] A brightness compensation value of each sub-display area is determined based on the target display brightness and the actual display brightness of the sub-display area.

[0017] In one embodiment, determining the brightness compensation value of each sub-display area based on the target display brightness and the actual display brightness of the sub-display area includes:

[0018] When the sub-display area is in full grayscale display, the brightness compensation value of each sub-display area is determined to be the difference between the target display brightness and the actual display brightness;

[0019] When the sub-display area is not a full grayscale display, the difference between the target display brightness and the actual display brightness is transformed using a 2.2 gamma curve to obtain a transformation amount, and the brightness compensation value of each sub-display area is determined as the transformation amount.

[0020] In one embodiment, before acquiring the target display brightness of the predetermined area of ​​the display region when displaying in full grayscale, the brightness compensation method further includes: performing global voltage drop compensation on the display panel.

[0021] In one embodiment, before the step of obtaining the target display brightness of the predetermined area of ​​the display area when the full grayscale is displayed, the method further includes:

[0022] Measure the actual display brightness of each sub-display area when displaying full grayscale;

[0023] Determine the resistance of each sub-display area based on the actual display brightness of each sub-display area, the screen current of the display area, the target display brightness, the voltage drop and the relationship model;

[0024] Preferably, the step of obtaining the voltage drop of the display area includes:

[0025] Acquiring a power supply voltage and a data voltage of the display panel, and determining a difference between the power supply voltage and the data voltage as a voltage drop in the display area;

[0026] Preferably, the screen current is proportional to the average display brightness of the display area, and the step of obtaining the screen current of the display area includes:

[0027] Get the average display brightness of the display area;

[0028] The screen current is determined based on the average display brightness.

[0029] In one embodiment, performing brightness compensation on the sub-display area based on the brightness compensation value includes:

[0030] Based on the brightness compensation value of the sub-display area of ​​the current frame, the brightness of the sub-display area of ​​the current frame is compensated; or,

[0031] Based on the brightness compensation value of the sub-display area of ​​the current frame, the brightness of the sub-display area of ​​the next frame is compensated.

[0032] A second aspect of the present application provides a display driver chip, which uses the above-mentioned brightness compensation method to compensate a display panel, wherein the display panel includes a display area, and the display driver chip includes:

[0033] An in-plane current statistics module, used to count the current flowing through the display area;

[0034] The first compensation module is connected to the in-plane current statistics module and is used to compensate for the brightness of the display area.

[0035] In one embodiment, the display driver chip further includes: a second compensation module, configured to perform global voltage drop compensation on the display panel.

[0036] In one embodiment, the first compensation module and the second compensation module are combined into one compensation module.

[0037] A third aspect of the present application provides a display panel, which includes the above-mentioned display driver chip.

[0038] The inventor of the present application has established a corresponding relationship model between the actual display brightness of each sub-display area and the voltage drop of the display area, the screen current of the display area and the resistance of the sub-display area, taking into account the resistance in the ELVDD metal line. The actual display brightness of each sub-display area can be determined according to the relationship model, and then the brightness compensation value of each sub-display area can be determined based on the actual display brightness of each sub-display area. The brightness compensation for each sub-display area is relatively accurate, and the phenomenon of over-brightness compensation almost does not occur. Moreover, the brightness compensation method of the present application is not affected by the display background, and accurate brightness compensation can be performed for any display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of a display panel in one embodiment of the present application.

[0040] Figure 2 The figure is a flow chart of a brightness compensation method for a display panel in one embodiment of the present application.

[0041] Figure 3 This is a schematic diagram of the relationship between pixel display brightness and pixel current in one embodiment of the present application.

[0042] Figure 4 This is a schematic flow chart of a brightness compensation method for a display panel in another embodiment of the present application.

[0043] Figure 5 This is a schematic flow chart of a brightness compensation method for a display panel in another embodiment of the present application.

[0044] Figure 6 This is a schematic flow chart of a brightness compensation method for a display panel in another embodiment of the present application.

[0045] Figure 7 A schematic diagram of the structure of a display driver chip in one embodiment of the present application.

[0046] Figure 8 This is a schematic diagram showing the structure of a driving chip in another embodiment of the present application.

[0047] Fig. 9 This is a schematic diagram showing the structure of a driving chip in another embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In addition, in order to better illustrate the present application, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods and means well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0050] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0051] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0052] The voltage division caused by the resistance of the ELVDD metal line in the display panel causes the voltage in the ELVDD metal line to gradually decrease in the direction away from the display driver chip. This phenomenon is called local IR drop (LIR for short). The local IR drop will cause uneven display. Therefore, it is necessary to compensate for the local voltage drop. The current local voltage drop compensation scheme generally obtains the brightness data within a single grayscale surface, determines the average brightness of each area and the average target brightness when displaying 255 grayscales, and the brightness compensation value of each area is the difference between the average brightness of each area and the average target brightness. This compensation method easily causes over-compensation of brightness in local areas and cannot solve the problem of uneven display.

[0053] In view of this, the present application provides a brightness compensation method for a display panel in a first aspect, referring to Figure 1 The structure diagram of the display panel shown in FIG. 1 is a diagram showing a structure of the display panel 100, wherein the display panel 100 includes a display area 110, and the display area includes a plurality of sub-display areas 111. Figure 2 The brightness compensation method shown is a flow chart of the brightness compensation method, and the brightness compensation method includes the following steps.

[0054] S100: Obtaining a voltage drop in a display area, a screen current in the display area, and a resistance of any sub-display area.

[0055] It should be noted that the screen current is equal to the sum of the currents of all pixels.

[0056] It can be understood that the multiple sub-display areas 111 can be arranged in an array. For example, the display area 110 can be divided into 9 sub-display areas 111, and the 9 sub-display areas 111 can be arranged in a 3*3 array. For example, the display area 110 can also be divided into 25 sub-display areas 111, and the 25 sub-display areas 111 can be arranged in a 5*5 array. The number of sub-display areas can be flexibly selected according to actual conditions.

[0057] In one embodiment, the step of obtaining the voltage drop of the display area, the screen current of the display area and the resistance of any sub-display area includes: obtaining the target display brightness of a predetermined area of ​​the display area when displaying in full grayscale, the voltage drop of the display area, the screen current of the display area and the resistance of any sub-display area.

[0058] It should be noted that full grayscale refers to 255 grayscales.

[0059] In one embodiment, obtaining the target display brightness of a predetermined area of ​​the display area when the full grayscale is displayed includes: obtaining the brightness of the center position of the display area when the full grayscale is displayed as the target display brightness. Thus, the brightness of the center position of the display area when the full grayscale is displayed is used as the target display brightness, and the brightness compensation value obtained subsequently is more accurate, which is conducive to avoiding the occurrence of brightness over-compensation.

[0060] In one embodiment, the screen current is proportional to the average display brightness of the display area, and obtaining the screen current of the display area includes: obtaining the average display brightness of the display area; and determining the screen current based on the average display brightness. Exemplarily, the relationship between the pixel current and the display brightness is as follows: Figure 3 As shown, the screen current can be determined based on the relationship curve between pixel current and display brightness and the average display brightness.

[0061] It should be noted that the average display brightness is equal to the sum of the brightness of all pixels.

[0062] In one embodiment, referring to Figure 4 The schematic flow chart of the brightness compensation method shown in the figure further includes the following steps before obtaining the target display brightness of a predetermined area of ​​the display area when the full grayscale is displayed.

[0063] S110: measuring the actual display brightness of each sub-display area during full grayscale display.

[0064] S120: Determine the resistance of each sub-display area based on the actual display brightness of each sub-display area, the screen current of the display area, the target display brightness, the voltage drop and the relationship model.

[0065] In one embodiment, obtaining the voltage drop in the display area includes: obtaining a power voltage and a data voltage of the display panel, and determining a difference between the power voltage and the data voltage as the voltage drop in the display area.

[0066] It is understandable that the target display brightness and the resistance of each sub-display area can be pre-stored in the display panel and can be directly called when brightness compensation is required.

[0067] S200: Based on voltage drop, screen current, resistance of any sub-display area, and preset relationship model Lum n ∝(KI*R n ) 2 , determine the actual display brightness of any sub-display area.

[0068] Among them, Lum n is the actual display brightness of the nth sub-display area, R n is the resistance of the nth sub-display area, I is the screen current, K is the voltage drop, n is the number of sub-display areas, and n is an integer greater than or equal to 1.

[0069] It can be understood that the above relationship model can be pre-stored in the display panel and can be directly called when brightness compensation is required, which is simple, convenient and easy to implement.

[0070] In one embodiment, based on the voltage drop, the screen current, the resistance of any sub-display area, and the preset relationship model Lum n ∝(KI*R n ) 2 The step of determining the actual display brightness of any sub-display area includes: based on the target display brightness, voltage drop, screen current, resistance of any sub-display area, and a preset relationship model: Lum n / L1=(KI*R n ) 2 / K 2 , determine the actual display brightness of any sub-display area, where L1 is the target display brightness and ∝ represents the mathematical symbol of direct proportion.

[0071] Under different backgrounds for the same grayscale, the main factor affecting the LIR effect is still the screen current; according to the pixel circuit current formula: Where ELVDD is the power supply voltage, W and L are the width and length of the driver transistor channel, μ is the effective carrier mobility, C ox is the capacitance per unit area of ​​the gate oxide layer, Vdata is the data voltage, and Vth is the threshold voltage of the driving transistor. It can be concluded that the pixel current is proportional to (ELVDD-Vdata) 2 The relationship between the pixel current and

[0072] ∝(ELVDD-Vdata) 2 The relationship between pixel current and pixel display brightness is shown in the figure below: Figure 4 As shown, the pixel display brightness is proportional to the pixel current, so the pixel display brightness Lum∝pixel current

[0073] ∝(ELVDD-Vdata) 2 , get pixel display brightness ∝ (ELVDD-Vdata) 2 .

[0074] After extensive research, the inventors of this application have found that: 1. Due to the resistance of the ELVDD metal line, there is a voltage drop △ELVDD in the power supply voltage at different positions in the display area. Therefore, at different positions, the actual power supply voltage is ELVDD-△ELVDD, so that the pixel display brightness Lum at different positions ∝ pixel current ∝ (ELVDD-△ELVDD-Vdata) 2 The inventors found that the voltage drop of the power supply at different locations

[0075] △ELVDD=screen current I*R (in-plane resistance at this position), thus obtaining the following relationship: power supply voltage drop △ELVDD∝screen current I. 2. When the same grayscale is displayed, ELVDD and Vdata are constants, and the constant K is used to represent ELVDD-Vdata. The in-plane line resistance R (in-plane line resistance R is the resistance of the ELVDD line) at the same position in the display area is approximately constant and is also a constant. The pixel display brightness Lum∝(ELVDD-△ELVDD-Vdata) at the same position 2 ∝(KI*R) 2 , we get Lum∝(KI*R) 2 . 3. The brightness of a single pixel Lum∝pixel current I', then the entire screen current I is equal to the sum of all pixel currents ∑I'. Since the current I' of each pixel is proportional to the brightness Lum of each pixel, the entire screen current I is proportional to the sum of all pixel brightnesses, and the sum of the entire pixel brightness ∑Lum is equal to the average brightness. Therefore, the entire screen current I is proportional to the average brightness; that is, the relationship is: screen current I∝∑Lum. 4. At different positions, the display brightness Lum∝(KI*R) 2 , we get the display brightness Lum∝(K'-∑Lum*R) 2 , the in-plane line resistance R is related to the position; K is a constant in the entire screen. Since the screen current I∝∑Lum, the ratio of ∑Lum to I is equal to the ratio of K' to K, that is, K'=K*∑Lum / I, and K' is also a constant. Based on the above research of the inventor, the inventor changes the resistance R of any sub-display area to n Assuming it is a constant value, the relationship model between the actual display brightness, screen current and resistance of any sub-display area is: Lum n ∝(KI*R n ) 2 At the same time, Lum n ∝(K'-

[0076] ∑Lum*R) 2 .

[0077] In a specific embodiment of the present application, the brightness of the center position of the display area when the full grayscale is displayed is obtained as the target display brightness L1. At this time, the inventor sets the resistance at the center position to 0. The target display brightness L1 at the center position is the actual display brightness. Based on the above relationship model Lum n ∝(KI*R n ) 2 , we get the following relationship: L1∝K 2 .

[0078] In another specific embodiment of the present application, Lum n ∝(K'-∑Lum*R) 2, the brightness of the center position of the display area when the full grayscale is displayed is obtained as the target display brightness L1. The inventor sets the resistance at the center position to 0. The target display brightness L1 at the center position is the actual display brightness, and the following relationship can be obtained: L1∝K' 2 .

[0079] It can be understood that when the resistance at the center of the display panel is set to 0, the resistances of different sub-display areas are relative to the resistance at the center, that is, R n It can be positive or negative in value.

[0080] In a specific embodiment, when the full grayscale display is displayed, the actual display brightness and the screen current I of each sub-display area are measured. The target display brightness L1 is known, K is a constant, and the relationship model Lum is used. n / L1=(KI*R n ) 2 / K 2 , the resistance R of each sub-display area can be calculated n .

[0081] In a specific embodiment, since the screen current I∝∑Lum, when the full grayscale is displayed, the actual display brightness of each sub-display area is measured, the target display brightness L1 is known, the average display brightness ∑Lum of the display area is the same as L1, K' is a constant, and the relational model Lum is used. n / L1=(K'-∑Lum*R n ) 2 / K' 2 , the resistance R of each sub-display area can be calculated n The proportional relationship with K', at this time, there is no need to calculate the resistance R of each sub-display area n The specific value of is helpful to simplify the calculation process.

[0082] S300: Determine a brightness compensation value of each sub display area based on the actual display brightness of the sub display area.

[0083] Optionally, determining the brightness compensation value of each sub display area based on the actual display brightness of the sub display area includes: determining the brightness compensation value of each sub display area based on the target display brightness and the actual display brightness of the sub display area.

[0084] In one embodiment, determining the brightness compensation value of each sub display area based on the target display brightness and the actual display brightness of the sub display area includes: when the sub display area is a full grayscale display, determining the brightness compensation value of each sub display area as the difference between the target display brightness and the actual display brightness.

[0085] In another embodiment, based on the target display brightness and the actual display brightness of the sub-display area, determining the brightness compensation value of each sub-display area includes: when the sub-display area is not a full grayscale display, using a 2.2 gamma curve to transform the difference between the target display brightness and the actual display brightness, obtaining a transformation amount, and determining the brightness compensation value of each sub-display area as the transformation amount. Thus, the brightness compensation method of the present application can be used to compensate for the brightness of the display screen under any display background, and the compensation accuracy is high, and there is almost no over-compensation phenomenon.

[0086] S400: Performing brightness compensation on the sub display area based on the brightness compensation value.

[0087] In one embodiment, performing brightness compensation on the sub display area based on the brightness compensation value includes: compensating the brightness of the sub display area of ​​the current frame based on the brightness compensation value of the sub display area of ​​the current frame.

[0088] In another embodiment, performing brightness compensation on the sub display area based on the brightness compensation value includes: compensating the brightness of the sub display area of ​​the next frame based on the brightness compensation value of the sub display area of ​​the current frame.

[0089] The inventor of the present application considers the resistance in the ELVDD metal line, sets the resistance of each sub-display area to a fixed value, and constructs a relationship model: Lum n / L1=(KI*R n ) 2 / K 2 , a corresponding relationship is established between the actual display brightness of each sub-display area and the target display brightness, the voltage drop of the display area, the screen current of the display area and the resistance of the sub-display area, so that the actual display brightness of each sub-display area can be accurately determined, and then the brightness compensation value of each sub-display area is determined based on the target display brightness and the actual display brightness of each sub-display area. The brightness compensation for each sub-display area is relatively accurate, and the phenomenon of over-brightness compensation almost does not occur; and the brightness compensation method of the present application is not affected by the display background, and accurate brightness compensation can be performed on any display screen.

[0090] In one embodiment, referring to Figure 5 or Figure 6 The schematic flow chart of the brightness compensation method shown in the figure shows that before obtaining the target display brightness of a predetermined area of ​​the display area when displaying in full grayscale, the brightness compensation method further includes the following steps.

[0091] S500: Perform global voltage drop compensation on the display panel.

[0092] With global voltage drop (GIR) compensation, the display panel brightness compensation effect is better and the display image uniformity is better.

[0093] In a specific embodiment, the display area is divided into 9 sub-display areas arranged in a 3*3 array, and the brightness compensation method of the display panel includes the following process:

[0094] 1. Measure the target display brightness L1 at the center of the display panel when it displays full grayscale. The average display brightness ∑Lum=100%*L1. The screen current can be determined by the average display brightness. The line resistances of the 9 sub-display areas are R1, R2, R3…R9, and the resistance at the center is 0.

[0095] 2. Measure the actual display brightness Lum1, Lum2, Lum3...Lum9 of each sub-display area, and use the relational model Lum n / L1=(KI*R n ) 2 / K 2 , calculate the resistance of each sub-display area, which is equivalent to the resistance at the center position. The resistance of the sub-display area can be positive or negative in value.

[0096] 3. Measure the average display brightness ∑Lum of any display screen and use the relational model Lum n / L1=(KI*R n ) 2 / K 2 , calculate the actual display brightness Lum of each sub-display area n '.

[0097] 4. Calculate the target display brightness L1 and the actual display brightness Lum of each sub-display area n ', △Lum1'=L1-Lum1', and determine the brightness compensation value based on the difference △Lum1'. Specifically, when the sub-display area is a full grayscale display, determine the brightness compensation value of each sub-display area as the difference △Lum1' between the target display brightness and the actual display brightness; when the sub-display area is a non-full grayscale display, use the 2.2 gamma curve to transform the difference △Lum1' between the target display brightness and the actual display brightness to obtain the transformation amount, and determine the brightness compensation value of each sub-display area as the transformation amount.

[0098] 5. Perform brightness compensation on the sub-display area based on the brightness compensation value.

[0099] For example, if any sub-display area is displayed in 255 grayscale, the other sub-display areas are displayed in 0 grayscale, and the display area of ​​any sub-display area accounts for 10% of the display area of ​​the entire display area, the average display brightness ∑Lum of the display area is 10%*L1, and the screen current I is determined by the average display brightness. n / L1=(KI*R n ) 2 / K2 , calculate the actual display brightness Lum of each sub-display area n ', then the brightness compensation value of each sub-display area is △Lum1', △Lum1'=L1-Lum n '.

[0100] The second aspect of the present application provides a display driver chip, which uses the above brightness compensation method to compensate a display panel, wherein the display panel includes a display area, and a reference Figure 7 The schematic diagram of the structure of the display driver chip shown in the figure shows that the display driver chip 200 includes: an in-plane current statistics module, which is used to count the current flowing through the display area; and a first compensation module, which is connected to the in-plane current statistics module and is used to compensate for the brightness of the display area. Thus, the in-plane current statistics module is used to count the pixel current of the display area. As described above, the pixel current is proportional to the pixel display brightness. The relationship between the current and the display brightness can be established by using the statistics of the current, so as to compensate the display brightness of the display panel by using the brightness compensation method described above.

[0101] In one embodiment, referring to Figure 8 The structural schematic diagram of the display driver chip shown in the figure further includes: a second compensation module, which is used to perform global voltage drop compensation on the display panel.

[0102] In one embodiment, referring to Fig. 9 In the structural schematic diagram of the display driver chip shown, the first compensation module and the second compensation module are combined into one compensation module.

[0103] It is understandable that the display driver chip may also include a storage module, such as a flash memory (FLASH) and a static random access memory (SRAM). The flash memory and the static random access memory are respectively connected to the first compensation module. The flash memory is used to write and / or read data in the aging compensation module; the static random access memory is used to output brightness compensation data to the display area.

[0104] It can be understood that the display driver chip can also include a 2.2 gamma curve conversion module. When the sub-display area is not a full grayscale display, the difference between the target display brightness and the actual display brightness is transformed using the 2.2 gamma curve to obtain a transformation amount, and the brightness compensation value of each sub-display area is determined as the transformation amount.

[0105] It can be understood that the target display brightness L1, the resistance value of each sub-display area, the target display brightness, the voltage drop, the screen current, the resistance of any sub-display area, and the preset relationship model: Lum n / L1=(KI*Rn ) 2 / K 2 It can be pre-stored in the display driver chip, and when brightness compensation is required, the required data can be directly called.

[0106] A third aspect of the present application provides a display panel, which includes the above-mentioned display driver chip.

[0107] It is understandable that, in addition to the above-mentioned compensation function, the display driver chip also has functions that a conventional display driver chip should have, which will not be elaborated herein.

[0108] In one embodiment, the display panel includes a display area and a non-display area. The non-display area surrounds the display area. The display area is used to display images. The display driver chip is arranged in the non-display area to drive the display panel to display the image excellently in the display area. The image displayed by the display panel of the present application has high uniformity.

[0109] Exemplarily, the display panel can be used to display color images or black and white images. Regardless of the type of image displayed, the display panel of the present application displays images of high quality, good uniformity, and uniform image quality, with almost no problems of excessive or too dark images.

[0110] Exemplarily, the type of display panel is not particularly limited, and the display panel may be a mobile phone, a tablet, a smart watch, etc. The display panel may be an OLED display panel or an LCD display panel.

[0111] It should be noted that, in addition to the display driver chip mentioned above, the display panel also includes an array substrate, a pixel layer, a packaging structure and other structures that a conventional display panel should have, which will not be described in detail here.

[0112] The present application is further described below in conjunction with specific embodiments. It should be noted that the following embodiments are only used to explain the present application and cannot be understood as limiting the present application.

[0113] Example 1

[0114] The display area is divided into 9 sub-display areas arranged in a 3*3 array, and the brightness compensation method of the display panel includes the following process:

[0115] 1. Measure the target display brightness of the display panel when it is in full grayscale display, which is L1, and the average display brightness

[0116] ∑Lum=100%*L1, the screen current can be determined by the average display brightness, and the line resistances of the 9 sub-display areas are R1, R2, R3…R9 respectively.

[0117] 2. Measure the actual display brightness Lum1, Lum2, Lum3...Lum9 of each sub-display area, and use the relational model Lum n / L1=(KI*R n ) 2 / K 2 , calculate the resistance of each sub-display area, where n is 1, 2, 3…9.

[0118] 3. Make any sub-display area display 255 grayscale, and the other sub-display areas display 0 grayscale, and the display area of ​​any sub-display area accounts for 10% of the display area of ​​the entire display area, and the average display brightness of the display area ∑Lum=10%*L1. The screen current can be determined by the average display brightness. Using the relationship model Lum n / L1=(KI*R n ) 2 / K 2 , calculate the actual display brightness Lum of each sub-display area n ', then the brightness compensation value of each sub-display area is △Lum1', △Lum1'=L1-Lum n '.

[0119] 4. Calculate the target display brightness L1 and the actual display brightness Lum of each sub-display area n ', △Lum1'=L1-Lum1', the brightness compensation value is determined based on the difference △Lum1', and the size of the brightness compensation value is equal to △Lum1'.

[0120] 5. Perform brightness compensation on the sub-display area based on the brightness compensation value.

[0121] The display brightness Lv of each sub-display area after compensation is obtained, and the brightness uniformity of the entire display area is calculated. According to the brightness compensation method of this embodiment, the brightness uniformity of the display screen can be improved to 97%.

[0122] Example 2

[0123] The brightness compensation method of the display panel is basically the same as that of Embodiment 1, except that, before step 1, it further includes:

[0124] Perform global voltage drop compensation on the display panel.

[0125] Obtain the display brightness Lv of each sub-display area after compensation, and calculate the brightness uniformity of the entire display area. In this embodiment, with the brightness compensation method of global voltage drop compensation, the brightness uniformity of the display screen can be improved to 98%.

[0126] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0127] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A brightness compensation method for a display panel, characterized in that: The display panel includes a display area, the display area includes a plurality of sub-display areas, and the brightness compensation method includes: Obtaining a voltage drop in the display area, a screen current in the display area, and a resistance of any sub-display area; Based on the voltage drop, the screen current, the resistance of any sub-display area, and a preset relationship model Lum n ∝(KI*R n ) 2 , determine the actual display brightness of any sub-display area, where Lum n is the actual display brightness of the nth sub-display area, R n is the resistance of the nth sub-display area, I is the screen current, K is the voltage drop, n is the number of sub-display areas, and n is an integer greater than or equal to 1; Determining a brightness compensation value of each sub-display area based on the actual display brightness of the sub-display area; Brightness compensation is performed on the sub-display area based on the brightness compensation value.

2. The brightness compensation method according to claim 1, characterized in that: The step of obtaining the voltage drop of the display area, the screen current of the display area and the resistance of any sub-display area comprises: Obtaining a target display brightness of a predetermined area of ​​the display area when displaying in full grayscale, a voltage drop of the display area, a screen current of the display area, and a resistance of any sub-display area; Preferably, the voltage drop, the screen current, the resistance of any sub-display area, and a preset relationship model Lum n ∝(KI*R n ) 2 The step of determining the actual display brightness of any sub-display area includes: Based on the target display brightness, the voltage drop, the screen current, the resistance of any sub-display area, and a preset relationship model: Lum n / L1=(KI*R n ) 2 / K 2 , determine the actual display brightness of any sub-display area, wherein L1 is the target display brightness; Preferably, the step of obtaining the target display brightness of the predetermined area of ​​the display area when the full grayscale display is performed comprises: Acquire the brightness of the center position of the display area when displaying in full grayscale as the target display brightness; Preferably, determining the brightness compensation value of each sub-display area based on the actual display brightness of the sub-display area comprises: A brightness compensation value of each sub display area is determined based on the target display brightness and the actual display brightness of the sub display area.

3. The brightness compensation method according to claim 2, characterized in that: Determining a brightness compensation value of each sub-display area based on the target display brightness and the actual display brightness of the sub-display area includes: When the sub-display area is in full grayscale display, determining the brightness compensation value of each sub-display area as the difference between the target display brightness and the actual display brightness; When the sub-display area is not a full grayscale display, the difference between the target display brightness and the actual display brightness is transformed using a 2.2 gamma curve to obtain a transformation amount, and the brightness compensation value of each sub-display area is determined as the transformation amount.

4. The brightness compensation method according to claim 2, characterized in that: Before acquiring the target display brightness of the predetermined area of ​​the display region when displaying in full grayscale, the brightness compensation method further includes: performing global voltage drop compensation on the display panel.

5. The brightness compensation method according to claim 2, characterized in that: Before the step of obtaining the target display brightness of the predetermined area of ​​the display area when the full grayscale is displayed, the method further includes: measuring the actual display brightness of each of the sub-display areas during full grayscale display; Determine the resistance of each of the sub-display areas based on the actual display brightness of each of the sub-display areas, the screen current of the display area, the target display brightness, the voltage drop and the relationship model; Preferably, the step of obtaining the voltage drop of the display area includes: Acquiring a power supply voltage and a data voltage of the display panel, and determining a difference between the power supply voltage and the data voltage as a voltage drop in the display area; Preferably, the screen current is proportional to the average display brightness of the display area, and the step of obtaining the screen current of the display area includes: Obtaining an average display brightness of the display area; The screen current is determined based on the average display brightness.

6. The brightness compensation method according to claim 1, characterized in that: Performing brightness compensation on the sub-display area based on the brightness compensation value includes: Based on the brightness compensation value of the sub display area in the current frame, the brightness of the sub display area in the current frame is compensated; or, Based on the brightness compensation value of the sub display area in the current frame, the brightness of the sub display area in the next frame is compensated.

7. A display driver chip, characterized in that: The display panel is compensated using the brightness compensation method according to any one of claims 1 to 6, the display panel comprises a display area, and the display driver chip comprises: An in-plane current statistics module, used for counting the current flowing through the display area; The first compensation module is connected to the in-plane current statistics module and is used to compensate for the brightness of the display area.

8. The display driver chip according to claim 7, characterized in that: Also includes: The second compensation module is used to perform global voltage drop compensation on the display panel.

9. The display driver chip according to claim 8, characterized in that: The first compensation module and the second compensation module are combined into one compensation module.

10. A display panel, characterized in that: A display driver chip comprising any one of claims 7 to 9.

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