Patent ID: 7742122

Claim:
A color image display device comprising a combination of light shutters, a color filter having color elements of at least three colors of red, green and blue corresponding to the light shutters, and a backlight for transmission illumination, wherein the backlight contains a LED, and under the following definitions: λ n nm represents a wavelength at every interval of 5 nm in the visible light range of from 380 to 780 nm; T R (λ n ) a spectral transmittance (%) at a wavelength λ n nm by a red pixel of the color filter; and I(λ n ) a relative emission intensity, normalized by a total emission intensity, at a wavelength λ n nm from the backlight, the device satisfies the following condition (1): I (620-680)× T R (620-680)≧1.1 (1) wherein T R (620-680) and I(620-680) represent the average transmittance (%) and the average relative emission intensity at 620 nm≦λ n ≦680 nm, respectively, and I(λ n ) is defined as follows: S ⁡ ( λ n ) = ∫ λ n - Δλ / 2 λ n + Δλ / 2 ⁢ s ⁡ ( λ ) ⁢ ⅆ λ Δλ I ⁡ ( λ n ) = s ⁡ ( λ n ) ∑ λ = 380 780 ⁢ s ⁡ ( λ n ) where S(λ) represents a measured value of emission intensity at a wavelength λ from the backlight, and Δλ=5 nm.