Contrast ratio for transmissive‐type TFT‐addressed LCDs under ambient‐light illumination

— The relationships between the contrast ratio, display luminance, and display diffuse reflectance are examined for the transmissive-type twisted-nematic TFT-LCD under ambient-light illumination. Expressions to estimate the contrast ratio under ambient light were derived. It is also shown that the contrast ratio is expressed as a simple function of the display luminance, the diffuse reflectance of the LCD, and the ambient-light illuminance, and has no relation to a contrast ratio under no ambient light if the ambient-light illuminance is high, e.g., over 50,000 lx.