Method of obtaining luminance and chromaticity of white in RGBW display device using RGB display device

Patent metadata

Field	Value
Publication number	US-9542876-B2
Application number	US-201414360698-A
Country	US
Kind code	B2
Filing date	May 4, 2014
Priority date	Apr 28, 2014
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A method of obtaining luminance and chromaticity of white in the RGBW display using RGB display, including; obtaining spectral values of a q grayscale of red sub-pixels, green sub-pixels and blue sub-pixels of the RGB display; obtaining spectral values of red, green and blue sub-pixels of a color filter in the RGB display; calculating a spectral value of the q greyscale of white in the RGB display as a spectral value of the q grayscale of the white sub-pixels of the RGBW display; calculating tristimulus values WX q , WY q and WZ q of the q greyscale of the white sub-pixels of the RGBW display; using the stimulus value WY q as a luminance of the q greyscale of the white sub-pixels of the RGBW display, and using the formulae
x = WX q WX q + WY q + WZ q ⁢ ⁢ and y = WY q WX q + WY q + WZ q
to calculate a chromaticity (x, y) of the white sub-pixel of the RGBW display.

First claim

The invention claimed is:

1. A method of obtaining luminance and chromaticity of white in a RGBW display device using a RGB display device, comprising:
1) obtaining spectral values of a q grayscale of red sub-pixels, green sub-pixels and blue sub-pixels of the RGB display device;
2) obtaining spectral values of red sub-pixels, green sub-pixels and blue sub-pixels of a color filter in the RGB display device;
3) calculating a spectral value of the q grayscale of white in the RGB display device as a spectral value of the q grayscale of white sub-pixels of the RGBW display device, based on the obtained spectral values of the q grayscale of the red sub-pixels, the green sub-pixels and the blue sub-pixels of the RGB display device and the obtained spectral values of the red sub-pixels, the green sub-pixels and the blue sub-pixels of the color filter;
4) calculating tristimulus values WX q , WY q and WZ q of the q grayscale of the white sub-pixels of the RGBW display device based on the obtained spectral value of the q grayscale of the white sub-pixels of the RGBW display device;
5) using the calculated stimulus value WY q of the q greyscale of the white sub-pixels of the RGBW display device as a luminance of the q greyscale of the white sub-pixels of the RGBW display device, and using the following formulae to calculate a chromaticity (x, y) of the q greyscale of the white sub-pixels of the RGBW display device,

x
=

WX
q

WX
q

+

WY
q

+

WZ
q

,

y
=

WY
q

WX
q

+

WY
q

+

WZ
q

,

wherein, q is a greyscale number.

2. The method of claim 1 , wherein specific implementation of step 3) includes: dividing the obtained spectral values of the q greyscale of the red sub-pixels, the green sub-pixels and the blue sub-pixels of the RGB display device by the obtained spectral values of the red sub-pixels, the green sub-pixels and the blue sub-pixels of the color filter respectively, so as to calculate spectral values of the q grayscale of white in the RGB display device corresponding to the spectral values of the q grayscale of the red sub-pixels, the green sub-pixels and the blue sub-pixels of the RGB display device respectively, wherein the spectral value of the q greyscale of white in the RGB display device corresponding to the spectral value of the q greyscale of the green sub-pixels of the RGB display device is used as the spectral value of the q greyscale of the white sub-pixel of the RGBW display device.

3. The method of claim 2 , wherein an aperture ratio of the sub-pixel in said RGB display device is identical to an aperture ratio of the sub-pixel in said RGBW display device; each sub-pixels in said RGB display device are identical in sizes; each sub-pixels in said RGBW display device are identical in sizes; the size of the sub-pixel in said RGBW display device is ¾ of the size of the sub-pixel in said RGB display device.

4. The method of claim 2 , wherein if an aperture ratio of each sub-pixels in said RGBW display device is m times of an aperture ratio of each sub-pixels in said RGB display device, then the tristimulus values of the q greyscale of the white sub-pixels of the RGBW display device are kmWX q , kmWY q , and kmWZ q , wherein k=(an area of a sub-pixel except the white sub-pixels in RGBW display device/an area of all sub-pixels in RGBW display device)/(an area of corresponding sub-pixel in RGB display device/an area of all sub-pixels in RGB display device).

5. The method of claim 2 , wherein if an aperture ratio of each sub-pixels in said RGBW display device is m times of an aperture ratio of each sub-pixels in said RGB display device, then the tristimulus values of the q greyscale of the white sub-pixels of the RGBW display device are kmWX q , kmWY q , and kmWZ q , wherein k=(an area of a sub-pixel except the white sub-pixels in RGBW display device/an area of all sub-pixels in RGBW display device)/(an area of corresponding sub-pixel in RGB display device/an area of all sub-pixels in RGB display device).

6. The method of claim 1 , wherein in step 4), the tristimulus values WX q , WY q and WZ q of the q greyscale of the white sub-pixels of the RGBW display device are calculated by using the following formulae:

WX
q

=

3
4

⁢
k
⁢

∫
λ

⁢

ϕ
⁡

(
λ
)

⁢

x
_

⁡

(
λ
)

⁢

⁢

ⅆ
λ

,

⁢

WY
q

=

3
4

⁢
k
⁢

∫
λ

Assignees

• Shenzhen China Star Optoelect

Inventors

• Wu Jinjun
• Zheng Weiwei

Classifications

• G09G3/006

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