Patent ID: 8154494

Claim:
A liquid crystal display device comprising: a liquid crystal modulation element including a first electrode, a second electrode, and a liquid crystal layer disposed between the first electrode and the second electrode; a potential difference providing unit that provides a potential difference between the first electrode and the second electrode; and an illumination optical system that illuminates the liquid crystal modulation element, wherein the liquid crystal display device has a first mode and a second mode, the liquid crystal display device arranged so that when operated in the first mode, the liquid crystal display device applies a positive voltage corresponding to one field and a negative voltage corresponding to one field alternately to the liquid crystal layer for each drive cycle corresponding to an image signal of one frame by using the potential difference providing unit while illuminating the liquid crystal modulation element by using the illumination optical system, and when operated in the second mode, the liquid crystal display device applies a direct current voltage to the liquid crystal layer for a period longer than 10 seconds, wherein a period of time for applying the direct current voltage is longer than ten times the drive cycle, wherein the liquid crystal modulation element is a reflective liquid crystal modulation element, and the first electrode and the second electrode are a transparent electrode and a mirror electrode, respectively, wherein the second mode is executed after the liquid crystal display device is powered OFF.