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

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 WXq, WYq and WZq 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 WYq 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.