Hitachi, Ltd.

Hitachi Displays, Ltd.

Hitachi Device Engineering Co., Ltd.

Panasonic Liquid Crystal Display Co., Ltd.

Shigeo Adachi

Katsumi Matsumoto

Iwao Takemoto

Hiroyuki Takahashi

Akira Ogura

Haruhisa Iida

Youichi Ooki

Haruhisa Ilda

Provided is a drive circuit low in power consumption and high in display quality for a liquid crystal display device that is used in a small-sized portable device. The liquid crystal display device includes liquid crystal display elements and a liquid crystal driving circuit. The liquid crystal driving circuit is mounted to one of the four sides of a liquid crystal display panel, and is capable of outputting two-system counter electrode voltages. A variable resistor circuit having a resistance value which is variably adjusted by a register is used to correct and output a gray scale voltage according to a position of a relevant scanning signal line. Equalization is also performed by short-circuiting two counter electrode signal lines.

Liquid crystal display device

The present invention realizes a liquid crystal display device which can be driven with a low voltage while preventing the degradation of liquid crystal by reducing a residual charge of a pixel electrode even when a drive circuit is abnormally stopped. As a field effect transistor which is formed on a pixel, a field effect transistor in a depletion mode which is turned on in a state that an OFF signal is not applied to a gate terminal of the transistor is used. A substrate voltage supply line which supplies a substrate voltage to pixel regions is provided, and the substrate voltage is supplied via a through hole formed in the pixel portion thus controlling an optimum threshold value in response to an input signal. Wiring is made in a peripheral portion of a display region such that video signal lines and the substrate voltage supply line intersect each other.

A liquid crystal display device which includes a first substrate, a second substrate, a liquid crystal composition sandwiched between the first substrate and the second substrate, and a plurality of pixels disposed on the first substrate. Each of the plurality of pixels is supplied with a video signal via a switching element. Each of the plurality of pixels is provided with a capacitance having two electrodes in which one is connected to a first electrode of a corresponding one of the plurality of pixels and another is supplied with a pixel-potential control signal by a pixel-potential control circuit. The pixel-potential control circuit enables selection of a first voltage level and a second voltage level.

Liquid crystal display device having a low-voltage driving circuit

A liquid crystal display device has a liquid crystal composition sandwiched between a pair of substrates, and a plurality of pixels disposed on one of the first substrates. Each of the pixels is supplied with a video signal via a switching element connected to a first electrode thereof, and is provided with a capacitance. One of two capacitance-forming electrodes forming the capacitance is connected to the first electrode of a corresponding one of the pixels, and another of the two capacitance-forming electrodes is supplied with a pixel-potential control signal. Polarity of the video signal reverses with respect to a first reference voltage with a repetition period, and the pixel-potential control signal alternates between two voltage levels of same polarity with respect to a second reference voltage such that a voltage swing on the first electrodes of the pixels becomes larger than that of the video signal.

Growing community of inventors

Chiba, Japan

Shigeo Adachi