Casio Computer Co., Ltd.

Toshihiro Mannoji

Tetsushi Yoshida

Toshiomi Ono

Soichi Sato

A liquid crystal cell includes scanning and signal electrodes, and a bistable nematic liquid crystal material sealed therein. The material has liquid crystal molecules alignable in first and second metastable aligned states by selective application of twist select voltages smaller than a reset voltage after application of the reset voltage. A tilt angle of the liquid crystal molecules is controlled in the first and second metastable aligned states in accordance with an effective value of a voltage applied between the opposing electrodes. A row driver, in accordance with display data, supplies a reset potential for applying the reset voltage between the electrodes, and a write-period voltage for designating a period for applying a voltage with an effective value according to the display data between the electrodes, to scanning electrodes. A data driver, in accordance with the display data, supplies a metastable-aligned-state selecting voltage for selectively applying a first metastable-aligned-state selecting voltage and a second metastable-aligned-state selecting voltage between the electrodes, and a write voltage corresponding to the voltage with the effective value according to the display data, to the signal electrodes in synchronism with the reset voltage and said write-period voltage.

Liquid crystal display device having bistable nematic liquid crystal and

A liquid crystal display device comprises a pair of substrates opposing each other, each having an electrode and an aligning film on an inner surface, a layer of bistable nematic liquid crystal sealed in a space between substrate, and two polarizing plates. A reset pulse voltage high enough to align the molecules almost vertically to the substrates is applied to the layer of liquid crystal. Then, a first state-selecting pulse voltage lower than the reset pulse voltage is applied between the electrodes, whereby the molecules of the liquid crystal assume a first metastable aligned state. Alternatively, a second state-selecting pulse voltage lower than the reset pulse voltage is applied between the electrodes, whereby the molecules of the liquid crystal assume a second metastable aligned state. The liquid crystal molecules are tilted at an angle to the substrates in accordance with the effective value of the first state-selecting pulse voltage while remaining in the first metastable aligned state, and are tilted at a different angle to the substrates in accordance with the effective value of the second state-selecting pulse voltage while remaining in the second metastable aligned state.

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Hachioji, Japan

Toshihiro Mannoji