Patent ID: 7436386

Claim:
Transmission type display device which is provided with plural light sources having different emission colors and which displays color images by making light emitted from said light sources pass through a color-blending part and controlling the light by an optical shutter, said transmission type display device comprising: at least three light detection devices installed in positions closer to said light sources than is said optical shutter; and a light source control circuit which controls emission intensities of said light sources of different colors to keep display chromaticity constant so that sensitivity reading values of said light detection devices are kept constant; wherein the spectral sensitivities of said light detection devices have characteristics at least approximately corresponding to characteristics obtained by multiplying a sum of the real number multiples of luminosity spectral characteristics by a spectral transmittance k(λ) from said light sources to a surface of said display and then dividing by a spectral transmittance k′(λ) from said light sources to the positions where said light detection devices are installed.