Casio Computer Co., Ltd.

Toshiomi Ono

Tetsushi Yoshida

Toshihiro Mannoji

Jiro Takei

Soichi Sato

Toshihiro Aoki

Tetsuya Kusuno

Seiichi Kizaki

Ken Kozima

Mikiya Itakura

A liquid crystal display device is provided which includes a scattering/transparent liquid crystal cell having a liquid crystal layer for controlling incident light in a scattered or transparent state in accordance with an applied electric field, and a selective reflector arranged on a side of the liquid crystal layer opposite to a side where observation is performed. The reflector has reflecting characteristics to cause light, which has come incident from a direction within a predetermined range of a viewing angle that allows observation of the liquid crystal cell, to reflect in a direction outside the range of the viewing angle on the side where observation is performed.

Reflection type liquid crystal display with selective reflector

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.

Bistable nematic liquid crystal which remains tilted in first and second

A liquid crystal display device includes a pair of substrates facing each, first and second electrodes formed on each inner surface of the substrates and arranged so that they are crossed and face each other, first and second aligning films covering each inner surface of the substrates and said first and second electrodes and provided with an aligning treatment in a direction respectively, and a liquid crystal member sealed between the substrates by a seal layer. The liquid crystal layer is twistingly aligned by the aligning force of said first and second aligning films at an angle of approx. 230.degree. to 250.degree., and has a positive dielectric anisotropy. The liquid crystal layer includes a liquid crystal member having a dielectric constant ratio .DELTA..epsilon./.epsilon..perp. defined as a ratio of the dielectric anisotropy .DELTA..epsilon. and the dielectric constant .epsilon..perp. with the direction orthogonal to the liquid crystal molecule axis of 2 or less, and a elastic constant ratio K.sub.33 /K.sub.11 defined as a ratio of a bent elastic constant K.sub.33 to a splay elastic constant K.sub.11 of 1.75 or more.

Liquid crystal display device with liquid crystal elastic constant ratio

A display cell is mounted on a color-compensating cell. The display cell has a pair of substrates each having an alignment-treated surface, a first liquid-crystal layer and electrodes. Multiplex drive signals are supplied to the electrodes. The color-compensating cell has a second liquid-crystal layer. The molecules of the first liquid-crystal layer are twisted by a twist angle ranging from 160.degree. to 270.degree.. The molecules of the second liquid-crystal layer are twisted by the same angle in the opposite direction. The substrates are alignment-treated in two directions, respectively, which are substantially at right angles to each other. One of the polarizing plates has an optical axis crossing at 35.degree. to 50.degree. with an aligning direction of the liquid crystal molecules on that substrate adjacent to the polarizing plate, and crossing with the optical axis of the other polarizing plate at right angles. The second liquid-crystal cell compensates for the coloring of the light passing through the display cell. The second liquid-crystal layer has retardation .DELTA.n.sub.2 .multidot.d.sub.2, which is less than the retardation .DELTA.n.sub.1 .multidot.d.sub.1 of said first liquid-crystal layer, for compensating for a decrease in the retardation .DELTA.n.sub.1 .multidot.d.sub.1, which has resulted from the excitation of the liquid-crystal molecules by application of a bias voltage to unselected pixels of the display cell.

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Machida, Japan

Toshiomi Ono