Liquid crystal display device

Abstract

Abstract PURPOSE:To extend the life of a back light without degrading display visibility by variably controlling the illuminance of the back light by an illumination control means according to the use condition of a liquid crystal display device. CONSTITUTION:The illumination control means 41 in addition to the liquid crystal display device 1 which has light transmittability from the rear side to the front side and the back light 2 which illuminates the display region of the liquid crystal display device 1 are provided. The illuminance of the back light 2 is variably controlled according to the use condition of the liquid crystal display device 1. Namely, this illumination control means 41 is subjected to the input operation by an operating switch 6 and outputs a supply instruction signal to a power supply circuit 3 to light the back light 2 only when the detection level of external light by an optical sensor 5 is below the prescribed value. The life of the back light 2 is thereby extended while the electric power consumption of the back light 2 is reduced.

Inventors

• 👤 Haruki Kinoshita

Bibliographic Details