PURPOSE: To permit easy multi-gradation display without being affected by an impressed voltage by providing an optical element which changes the progressing direction of light to a side for observing a liquid crystal panel which receives the light from a light source.
CONSTITUTION: The optical element 3 which changes the progressing direction of the light is provided in proximity to the surface of the liquid crystal 1 formed by hermetically sealing a liquid crystal between transparent substrates on the side for observing the liquid crystal 1 of a liquid crystal display device having the above-mentioned liquid crystal panel 1. More specifically, a prism 3 is disposed on the exit side of the liquid crystal panel 1 where the light from the light source 2 is received; namely, on the observation side, to change the direction of the angle θ generated on the exit side to a front direction. The inclination of an electrooptic characteristic (ratio between quantity of transmission and voltage) is gentler if the prism 3 is used. The gentler control of the transmittance by changing the impressed voltage for controlling transparent electrodes is consequently permitted and the influence of noise on the impressed voltage; i.e., data voltage, is decreased. The multi-gradation display by the voltage control is thereby permitted.
KOIKE YOSHIRO
OKAWA YASUSHI
YOSHIDA HIDESHI
