LIQUID CRYSTAL DISPLAY DEVICE WITH LIGHT CONDENSING MECHANISM

摘要

PROBLEM TO BE SOLVED: To reduce the electric power consumption of an LCD with a light condensing mechanism and to prevent the degradation in visibility when an external light quantity changes. SOLUTION: A photodetector 1 directly receives the external light, a light source 114 is put on and off according to its output and opens and closes a cover 121. Since the light source 114 may be put out at adequate timing, the electric power consumption may be reduced. A photodetector 2 is installed to face a back within a casing 120 the LCD and receives the external light collected from a light condensing part 115 and the internal light emitted by the light source 114. The LCD panel 100 improves the visibility by automatically fluctuating the luminance and contrast ratio according to the output of the photodetector 2.