Liquid crystal display device

Abstract

Abstract PURPOSE:To prevent the alteration in display characteristic caused by the change of use conditions such as ambient temperature and illumination, etc., by respectively forming a temp. sensor and an illumination sensor of amorphous silicon on a substrate where a thin film transistor is formed. CONSTITUTION:The voltage of a power source 42 is controlled according to an output from the temp. sensor 45, namely, the voltage of the power source of the driving transistor of a source driving circuit 41 is controlled. When the ambient temperature rises, an effective voltage impressed on the electrode of an image element lowers, and not only the contrast but also the brightness lower. But, by controlling the power source 42 according to the output from the temp. sensor 45, the amplitude of a source driving signal from the source driving circuit 41 is made large and the ON level of the liquid crystal is kept nearly constant. And the illumination sensor 54 outputs an output according to illumination of external light. Namely, according to the output from the illumination sensor 54, a dimmer 44 is controlled by a control part 61 and the illumination of the radiated light from a light source for backlight 43 is raised when the illumination of the external light 53 rises. Thus the favorable contrast can be always obtained.

Inventors

• 👤 Yasuhiro Ukai

Bibliographic Details