Method and apparatus for gamma debugging

Patent metadata

Field	Value
Publication number	US-11823609-B2
Application number	US-202217835447-A
Country	US
Kind code	B2
Filing date	Jun 8, 2022
Priority date	Jun 29, 2020
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A method for Gamma debugging. The method for Gamma debugging is applicable to a display panel including a first display area and a second display area. A light transmittance of the first display area is greater than that of the second display area. The method includes: selecting, in the second display area, a test area having a same shape and size as the first display area; obtaining a first present brightness value when the test area corresponds to a specified register value under a specified grayscale; determining a plurality of first target brightness values when the first display area corresponds to a plurality of register values under the specified grayscale, according to the first present brightness value and a linear relationship between register values and brightness of the display panel; and performing Gamma debugging on the first display area according to the first target brightness values.

First claim

What is claimed is:

1. A method for Gamma debugging, applicable to a display panel comprising a first display area and a second display area, a light transmittance of the first display area being greater than a light transmittance of the second display area, the method comprising:
selecting, in the second display area, a test area which has a same shape and size as the first display area;
obtaining a first present brightness value of the test area when the test area corresponds to a specified register value under a specified grayscale;
determining a plurality of first target brightness values of the first display area when the first display area corresponds to a plurality of register values under the specified grayscale, according to the first present brightness value and a linear relationship between register values and brightness of the display panel; and
performing Gamma debugging on the first display area according to the plurality of first target brightness values,
wherein determining a plurality of first target brightness values of the first display area when the first display area corresponds to the plurality of register values under the specified grayscale, according to the first present brightness value and the linear relationship between register values and brightness of the display panel comprises:
setting the first present brightness value as the first target brightness value of the first display area when the first display area corresponds to the specified register value under the specified grayscale;
obtaining a second present brightness value of the second display area when the second display area corresponds to the specified register value under the specified grayscale; and
setting a ratio of a first product to a second product as the first target brightness value of the first display area when the first display area corresponds to another register value under the specified grayscale,
wherein the first product is a product of the second present brightness value and the another register value, and the second product is a product of the specified register value and a coefficient M which is a ratio of the second present brightness value to the first present brightness value, and the another register value is any one of the plurality of register values other than the specified register value.

2. The method for Gamma debugging of claim 1 ,
wherein determining a plurality of first target brightness values of the first display area when the first display area corresponds to the plurality of register values under the specified grayscale, according to the first present brightness value and the linear relationship between register values and brightness of the display panel comprises:
setting the first present brightness value as the first target brightness value of the first display area when the first display area corresponds to the specified register value under the specified grayscale;
calculating a third product of the first present brightness value and another register value; and
setting a ratio of the third product to the specified register value as the first target brightness value of the first display area when the first display area corresponds to the another register value under the specified grayscale,
wherein the another register value is any one of the plurality of register values other than the specified register value.

3. The method for Gamma debugging of claim 1 , wherein the second display area further comprises an auxiliary area at least partially surrounding the test area, and before obtaining the first present brightness value of the test area when the test area corresponds to the specified register value under the specified grayscale, the method further comprises:
controlling the auxiliary area to all black display, and controlling the first display area and any area of the second display area other than the auxiliary area to gray scale display.

4. The method for Gamma debugging of claim 1 , wherein performing Gamma debugging on the first display area according to the plurality of first target brightness values comprises:
performing Gamma debugging on the first display area according to each of the plurality of first target brightness values, to obtain a target data voltage value corresponding to each sub-pixel in the first display area.

5. The method for Gamma debugging of claim 4 ,
wherein the first display area comprises n rows of sub-pixels, n is a positive integer greater than or equal to 1, and after performing Gamma debugging on the first display area according to the plurality of first target brightness values, the method further comprises:
determining a target current value corresponding to each sub-pixel in the first display area, based on the target data voltage value corresponding to each sub-pixel in the first display area, the target current value corresponding to each sub-pixel in the first display area being calculated in accordance with an equation below:
1 =k ( Vdd −Data) 2 ,

wherein k is a known coefficient and is determined by a channel length and width of a transistor in a pixel circuit corresponding to the sub-pixel.

6. The method for Gamma debugging of claim 5 , further comprising: determining a supply voltage value actually obtained by each sub-pixel in the first display area based on the target current value corresponding to each sub-pixel in the first display area,
a data voltage value outputted by a data driving circuit of the display panel being calculated in accordance with an equation below:
Data′=Data−( Vdd−Vdd x ),

wherein Data′ denotes the data voltage value to be outputted by the data driving circuit of the display panel, Data denotes the target data voltage value, Vdd denotes a supply voltage value outputted by a supply voltage terminal of the first display area, Vdd x denotes a supply voltage value actually obtained by each sub-pixel in row x of the first display area, and x is a positive integer greater than or equal to 1 and less than or equal to n.

7. The method for Gamma debugging of claim 6 , wherein each column of sub-pixels in the first display area are electrically connected to the supply voltage terminal of the first display area via a supply voltage line, and the sub-pixels, closest to the supply voltage line, in columns of sub-pixels constitute a first row of sub-pixels, and determining the supply voltage value actually obtained by each sub-pixel in the first display area based on the target current value corresponding to each sub-pixel in the first display area comprises:
calculating the supply voltage value actually obtained by each sub-pixel in the first display area in accordance with an equation below:
Vdd x =Vdd −( x×I tatal −Σ i=1 x−1 ( x−i ) I i )× R,

wherein I tatal denotes a total current value outputted by the supply voltage terminal of the first display area, I i denotes a target current value corresponding to an i th row of sub-pixels, i is greater than or equal to 1 and less than or equal to x, and R denotes a resistance value of a supply voltage line between two adjacent rows of sub-pixels.

8. The method for Gamma debugging of claim 1 , wherein before selecting the test area, the method further comprises:
determining a second target brightness value of the second display area under the specified grayscale according to a target requirement; and
performing Gamma debugging on the second display area according to the second target brightness value, so that a difference between an actual brightness value of the second display area and the second target brightness value of the second display area is within a preset range.

9. The method for Gamma debugging of claim 1 , wherein a center point of

Assignees

• Kunshan Govisionox Optoelectronics Co Ltd

Inventors

• Wang Yuqing
• Chen Xinquan
• Zhang Xiaobao
• Han Chong

Classifications

• G09G3/2074 Primary

  using sub-pixels · CPC title

• G09G3/006 Primary

  Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309) · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title