Mitsubishi Denki Kabushiki Kaisha

Shigeharu Yoshikawa

Katsumi Asakawa

Kouhei Tamano

Hiroaki Ishitani

Hiroaki Sugiura

Kozo Ishida

Akihisa Miyata

A projection-type liquid crystal display apparatus that prevents deterioration of a projected image occurring attributable to lowering of the temperature of a liquid crystal panel, the difference in the temperature between the liquid crystal panels and temperature inclination in the liquid crystal panel. A projection-type liquid crystal display apparatus having a light source 1, liquid crystal panels 12, 13 and 14 for modulating a light beam emitted by the light source 1, a projection lens 21 for projecting the modulated light beam onto a screen 28, temperature detectors 25, 26 and 27 for detecting the temperatures of portions adjacent to the liquid crystal panels 12, 13 and 14, heater elements 18, 19 and 20 disposed adjacent to image forming surfaces of the liquid crystal panels 12, 13 and 14 and on a light path of a light beam emitted from the light source 1, a drive circuit 40 for operating the heater elements 18, 19 and 20 and a control unit 35 for controlling the heat generating performance of the heater elements 18, 19 and 20 in accordance with values detected by the temperature detectors 25, 26 and 27.

Projection-type liquid crystal display apparatus

A projection-type liquid crystal display device having a light source for emitting a luminous flux; a liquid crystal light valve for modulating the luminous flux emitted by the light source means; a liquid crystal drive circuit for applying the common voltage to the common electrode and the video signal to the source electrode; a projection lens for projecting the luminous flux modulated by the liquid crystal light valve onto a screen; a liquid crystal temperature detector for detecting temperature in the vicinity of the liquid crystal light valve; and a controller. The controller controls the common voltage and/or the source voltage on the basis of values detected by the liquid crystal temperature detector in such a way that fluctuation in the light transmittance of the liquid crystal light valve means is reduced.

Projection-type liquid crystal display device

Growing community of inventors

Tokyo, Japan

Shigeharu Yoshikawa