# US 12,112,676 B2 · Demura method for display panel

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- Number: US 12,112,676 B2
- Document ID: US12112676B2
- Status: Granted
- Kind: B2
- Application number: 17/618,406
- Filed: 2021-11-03
- Published: 2024-02-22
- Granted: 2024-10-08
- Earliest claimed: 2021-09-06
- Assignees: Huizhou China Star Optoelectronics Display Co., Ltd.; Tcl China Star Optoelectronics Technology Co., Ltd.
- Applicants: Huizhou China Star Optoelectronics Display Co., Ltd.; Tcl China Star Optoelectronics Technology Co., Ltd.
- Inventors: Jinfeng Liu; Yue Fan
- Web page: https://patentgrep.com/patent/US12112676B2

## CPC

- G09G 3/2007: {Display of intermediate tones}
- G09G 3/3208: organic, e.g. using organic light-emitting diodes [OLED]
- G09G 3/36: using liquid crystals
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/0271: Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
- G09G 2360/145: the light originating from the display screen
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

A demura method for a display panel includes the steps: obtaining brightness data of a display image at a gray scale value; calculating the brightness data of the display image to obtain demura data of the pixel; dividing bits of the demura data of the pixel into first bits and second bits according to a bit length of the pixel, setting an integer gray scale value of the pixel according to the first bits, and setting a mixed gray scale value of the pixel according to the second bits.

## Claims

### Claim 1

A demura method for a display panel, comprising:
obtaining brightness data of a display image displayed by the display panel at a given gray scale value;
calculating the brightness data of the display image to obtain demura data of each pixel of the display panel; and
dividing bits of the demura data of each pixel into first bits and second bits according to a bit length of the pixel of the display panel, setting an integer gray scale value of each pixel according to the first bits, and setting a mixed gray scale value of each pixel according to the second bits,
wherein a bit length of the second bits is corresponding to a total frame number, wherein the total frame number is a sum of a number of frames displaying a value of the integer gray scale value plus one and a number of frames displaying the integer gray scale value for each pixel.

### Claim 2 (depends on 1)

The demura method for the display panel according to claim 1, wherein the first bits are high order bits of the demura data corresponding to the bit length of the pixel of the display panel, and the second bits are low order bits of the demura data except the first bits.

### Claim 3 (depends on 1)

The demura method for the display panel according to claim 1, wherein the mixed gray scale value is a ratio of the number of the frames displaying the value of the integer gray scale value plus one to the total frame number.

### Claim 4 (depends on 1)

The demura method for the display panel according to claim 1, wherein a bit length of the demura data is greater than the bit length of the pixel of the display panel.

### Claim 5 (depends on 1)

The demura method for the display panel according to claim 1, wherein a bit length of the demura data is 12 bits, and the bit length of the pixel of the display panel is 8 bits.

### Claim 6 (depends on 1)

The demura method for the display panel according to claim 1, further comprising:
generating a demura table and a mixed table according to the integer gray scale value and the mixed gray scale value of the demura data of each pixel, respectively.

### Claim 7 (depends on 1)

The demura method for the display panel according to claim 1, wherein the step of obtaining the brightness data of the display image in the display panel at the given gray scale value comprises:
performing flat-field correction, black level correction, and linearity correction on an imaging device; and
obtaining the brightness data of the display image in the display panel at the given gray scale value through the imaging device.

### Claim 8 (depends on 1)

The demura method for the display panel according to claim 1, wherein before the step of calculating the brightness data of the display image to obtain the demura data of each pixel of the display panel, the demura method further comprises:
performing Moire elimination and distortion correction on the display image.

### Claim 9 (depends on 1)

The demura method for the display panel according to claim 1, wherein the display panel is a liquid crystal display panel or an organic light-emitting diode display panel.

### Claim 10

A demura method for a display panel, comprising:
obtaining brightness data of a display image displayed by the display panel at a given gray scale value;
calculating the brightness data of the display image to obtain demura data of each pixel of the display panel; and
dividing bits of the demura data of each pixel into first bits and second bits according to a bit length of the pixel of the display panel, setting an integer gray scale value of each pixel according to the first bits, and setting a mixed gray scale value of each pixel according to the second bits;
wherein the first bits are high order bits of the demura data corresponding to the bit length of the pixel of the display panel, and the second bits are low order bits of the demura data except the first bits;
wherein a bit length of the demura data is greater than the bit length of the pixel of the display panel, and
wherein a bit length of the second bits is corresponding to a total frame number, wherein the total frame number is a sum of a number of frames displaying a value of the integer gray scale value plus one and a number of frames displaying the integer gray scale value for each pixel.

### Claim 11 (depends on 10)

The demura method for the display panel according to claim 10, wherein the mixed gray scale value is a ratio of the number of the frames displaying the value of the integer gray scale value plus one to the total frame number.

### Claim 12 (depends on 10)

The demura method for the display panel according to claim 10, further comprising:
generating a demura table and a mixed table according to the integer gray scale value and the mixed gray scale value of the demura data of each pixel, respectively.

### Claim 13 (depends on 10)

The demura method for the display panel according to claim 10, wherein the step of obtaining the brightness data of the display image in the display panel at the given gray scale value comprises:
performing flat-field correction, black level correction, and linearity correction on an imaging device; and
obtaining the brightness data of the display image in the display panel at the given gray scale value through the imaging device.

### Claim 14

A demura method for a display panel, comprising:
obtaining brightness data of a display image displayed by the display panel at a given gray scale value;
performing Moire elimination and distortion correction on the display image;
calculating the brightness data of the display image to obtain demura data of each pixel of the display panel;
dividing bits of the demura data of each pixel into first bits and second bits according to a bit length of the pixel of the display panel, setting an integer gray scale value of each pixel according to the first bits, and setting a mixed gray scale value of each pixel according to the second bits; and
generating a demura table and a mixed table according to the integer gray scale value and the mixed gray scale value of the demura data of each pixel, respectively,
wherein a bit length of the second bits is corresponding to a total frame number, wherein the total frame number is a sum of a number of frames displaying a value of the integer gray scale value plus one and a number of frames displaying the integer gray scale value for each pixel.

### Claim 15 (depends on 14)

The demura method of the display panel according to claim 14, wherein the first bits are high order bits of the demura data corresponding to the bit length of the pixel of the display panel, and the second bits are low order bits of the demura data except the first bits.

### Claim 16 (depends on 14)

The demura method of the display panel according to claim 14, wherein the mixed gray scale value is a ratio of the number of the frames displaying the value of the integer gray scale value plus one to the total frame number.

### Claim 17 (depends on 14)

The demura method of the display panel according to claim 14, wherein a bit length of the demura data is greater than the bit length of the pixel of the display panel.