Display device and white balance adjusting method thereof

Patent metadata

Field	Value
Publication number	US-2021027726-A1
Application number	US-201716639476-A
Country	US
Kind code	A1
Filing date	Dec 13, 2017
Priority date	Aug 16, 2017
Publication date	Jan 28, 2021
Grant date	—

Abstract

A display device and a white balance adjusting method of the display device are provided. The white balance adjusting method comprises the following steps: measuring a stimulus value of each of gray scales of each of pixels of a panel; defining a highest voltage of each of the pixels at a maximum of the stimulus value; re-defining a white highest voltage using a first white balance pixel look-up table according to the highest voltage of each of the pixels; defining a target value for a white balance color pixel degree adjustment according to the white highest voltage and a corresponding white chromaticity; and acquiring an adjusted second white balance pixel look-up table to complete a white balance adjustment of the display device.

First claim

What is claimed is:

1 . A white balance adjusting method of a display device, comprising:
measuring a stimulus value of each of gray scales of each of pixels of a panel; defining a highest voltage of each of the pixels at a maximum of the stimulus value; re-defining a white highest voltage using a first white balance pixel look-up table according to the highest voltage of each of the pixels; defining a target value for a white balance color pixel degree adjustment according to the white highest voltage and a corresponding white chromaticity; and acquiring an adjusted second white balance pixel look-up table to complete a white balance adjustment of the display device.

2 . The white balance adjusting method of a display device according to claim 1 , wherein the pixels comprises a red pixel, a green pixel and a blue pixel.

3 . The white balance adjusting method of a display device according to claim 2 , wherein a stimulus value of each of gray scales of each of pixels comprises a three-coordinate system stimulus value of the red pixel corresponding to each of the gray scales in a standard chromaticity system, a three-coordinate system stimulus value of the green pixel corresponding to each of the gray scales in a standard chromaticity system and a three-coordinate system stimulus value of the blue pixel corresponding to each of the gray scales in a standard chromaticity system.

4 . The white balance adjusting method of a display device according to claim 2 , wherein, after measuring the stimulus value of each of the gray scales of each of the pixels of the panel, the method further comprises:
finding out reversal gray scale values of the red pixel, the green pixel and the blue pixel of each of coordinate systems in a standard chromaticity system.

5 . The white balance adjusting method of a display device according to claim 2 , wherein, after defining the white highest voltage and the corresponding white chromaticity at the target value for the white balance color pixel degree adjustment, the method further comprises:
using a root-mean-square minimum error method to calculate to obtain red pixel, green pixel and blue pixel look-up tables of each of the gray scales corresponding to an adjusted white to serve as an adjusted second white balance pixel look-up table to keep a white brightness gamma value to be equal to 2.2.

6 . The white balance adjusting method of a display device according to claim 5 , wherein the white brightness gamma value to be equal to 2.2 satisfies the following formulas:
Y ( R -LUT)+ Y ( G -LUT)+ Y ( B -LUT)=gamma2.2; and  1)
Min(( Wx−Wx 0){circumflex over ( )}2+( Wy−Wy 0){circumflex over ( )}2),  2)
wherein Y represents the Y coordinate system of the standard chromaticity system, R represents the gray scale value of the red pixel under different gray scale voltages, G represents the gray scale value of the green pixel under different gray scale voltages, B represents the gray scale value of the blue pixel under different gray scale voltages, LUT represents the gray scale value corresponding to each color of the second white balance pixel look-up table in different gray scale voltages; and Wx represents the coordinate value of the white chromaticity X coordinate system, Wy represents the coordinate value of the white brightness Y coordinate system, Wx 0 represents the coordinate value of the dark state white chromaticity X coordinate system, and Wy 0 represents the coordinate value of the dark state white chromaticity Y coordinate system.

7 . The white balance adjusting method of a display device according to claim 1 , wherein the pixels comprises a red pixel, a green pixel and a blue pixel; and
a stimulus value of each of gray scales of each of pixels comprises a three-coordinate system stimulus value of the red pixel corresponding to each of the gray scales in the standard chromaticity system, a three-coordinate system stimulus value of the green pixel corresponding to each of the gray scales in the standard chromaticity system and a three-coordinate system stimulus value of the blue pixel corresponding to each of the gray scales in the standard chromaticity system; and after measuring the stimulus value of each of the gray scales of each of the pixels of the panel, the method further comprising: finding out reversal gray scale values of the red pixel, the green pixel and the blue pixel of each of coordinate systems in a standard chromaticity system.

8 . The white balance adjusting method of a display device according to claim 1 , wherein the pixels comprises a red pixel, a green pixel and a blue pixel; and
a stimulus value of each of gray scales of each of pixels comprises the three-coordinate system stimulus value of the red pixel corresponding to each of the gray scales in the standard chromaticity system, the three-coordinate system stimulus value of the green pixel corresponding to each of the gray scales in the standard chromaticity system and the three-coordinate system stimulus value of the blue pixel corresponding to each of the gray scales in the standard chromaticity system; and after defining the white highest voltage and the corresponding white chromaticity at the target value for the white balance color pixel degree adjustment, the method further comprising: using a root-mean-square minimum error method to calculate to obtain red pixel, green pixel and blue pixel look-up tables of each of the gray scales corresponding to an adjusted white to serve as an adjusted second white balance pixel look-up table to keep a white brightness gamma value to be equal to 2.2; the white brightness gamma value to be equal to 2.2 satisfies the following formulas:
Y ( R -LUT)+ Y ( G -LUT)+ Y ( B -LUT)=gamma2.2; and  1)

Min(( Wx−Wx 0){circumflex over ( )}2+( Wy−Wy 0){circumflex over ( )}2),  2)

wherein Y represents the Y coordinate system of the standard chromaticity system, R represents the gray scale value of the red pixel under different gray scale voltages, G represents the gray scale value of the green pixel under different gray scale voltages, B represents the gray scale value of the blue pixel under different gray scale voltages, LUT represents the gray scale value corresponding to each color of the second white balance pixel look-up table in different gray scale voltages; and Wx represents the coordinate value of the white chromaticity X coordinate system, Wy represents the coordinate value of the white brightness Y coordinate system, Wx 0 represents the coordinate value of the dark state white chromaticity X coordinate system, and Wy 0 represents the coordinate value of the dark state white chromaticity Y coordinate system.

9 . The white balance adjusting method of a display device according to claim 1 , wherein the pixels comprises a red pixel, a green pixel and a blue pixel; and
a stimulus value of each of gray scales of each of pixels comprises a three-coordinate system stimulus value of the red pixel corresponding to each of the gray scales in the standard chromaticity system, a three-coordinate system stimulus value of the green pixel corresponding to each of the gray scales in the standard chromaticity system and a three-coordinate system stimulus value of the blue pixel corresponding to each of the gray scales in the standard chromaticity system; and after measuring the stimulus value of each of the gray scales of each of the pixels of the panel, the method further comprising: finding out reversal gray scale values of the red pixel, the green pixel and the blue pixel of each of coordinate systems in a standard chromaticity system; after defining the white highest voltage and the corresponding white chromaticity at the target value for the white balan

Assignees

• Hkc Corp Ltd
• Chongqing Hkc Optoelectronics Tech Co Ltd

Inventors

• Lee Chia-Hang
• Shi jing-ren

Classifications

• G09G3/3607 Primary

  for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels (display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127) · CPC title

• H04N9/73

  Colour balance circuits, e.g. white balance circuits or colour temperature control (camera processing pipelines for colour balance H04N23/88) · CPC title

• H04N9/3182

  Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607) · CPC title

• G09G2360/145

  the light originating from the display screen · CPC title

• G09G2320/0666

  for control of colour parameters, e.g. colour temperature · CPC title