Nec Corporation

Kohji Nakashima

Osamu Sukegawa

Makoto Watanabe

Susumu Ohi

Hirofumi Ihara

Shin Koide

Akihiro Yajima

An active-matrix liquid crystal display device applies a voltage modulated with a high-frequency AC voltage to a common electrode disposed on a substrate which confronts a substrate having a plurality of thin-film transistors as switching elements for pixel electrodes. The modulated voltage applied to the common electrode is effective to reduce the phenomenon of a residual image retained for a long period of time; thereby improving the quality of displayed images.

Liquid crystal display device having an alternating common electrode

An active matrix type LCD panel includes an active matrix portion including a plurality of this film transistors, a plurality of scan signal lines and a plurality of data lines, and a shunt bus formation portion including at least first and second bus lines formed independently of each other. The first shunt bus line is connected to the scan signal lines 1 and the second shunt bus line is connected to the data lines to thereby protect the transistors against a surge voltage such as electrostatic charges and facilitate a test for short-circuit conditions between the adjacent lines.

LCD panel having a plurality of shunt buses

A thin-film transistor (TFT) array for preventing the light reflected inside a liquid crystal panel from entering a channel layer, while suppressing an increase of stray capacitance. A light shading film and an antireflection film atop source and drain electrodes are made of semiconductor layers and are spaced from each other on a TFT. The reduction in reflected light prevents an increase in an off current and therefore improves the quality of a liquid crystal display.

Thin-film transistor array having light shading film and antireflection

In an active matrix liquid-crystal display apparatus, in order to increase display quality, compensator capacitance is provided to compensate pixel voltage fluctuation resulted from increase of parasitic capacitance caused by light shield film. A capacitance film is fabricated between a pixel electrode and the adjacent image signal line to provide compensator capacitance. Signals are supplied to each image signal line that a positive electric voltage and a negative electric voltage are applied to the liquid-crystal layer of the adjacent pixels along the scan signal line, alternately from pixels to pixels. The compensator capacitance is set to approximately the same as parasitic capacitance caused by the light shield film so that modulation noise caused by the light shield film is offset by modulation noise caused by the compensator capacitance when the adjacent image signal line is in opposite phase. Thus the voltage fluctuation of the pixel electrode can be compensated.

Growing community of inventors

Tokyo, Japan

Kohji Nakashima