Bell Telephone Laboratories

At&t Bell Laboratories

Dwight W Berreman

William R Heffner

Allan R Kmetz

A matrix addressed, bistable liquid crystal optical display is disclosed. The display includes a liquid crystal twist cell which has at least two states which are stable in the presence of a single given holding voltage. A form of 3:1 matrix addressing is used in the display which enhances operational characteristics.

Matrix addressed bistable liquid crystal display

A bistable liquid crystal twist cell is disclosed. The cell has at least two states which are stable in the presence of a single given holding voltage. The states may be switched from one to the other by short-term variation in the magnitude of the applied voltage.

Bistable liquid crystal twist cell

A bistable liquid crystal twist cell is disclosed. The cell is characterized by at least two stable states which exist indefinitely as long as not external energy is applied to the cell. External energy is necessary only for switching the cell between the stable states. Cell configurations which permit the fabrication of patterned displays are additionally disclosed. Specific embodiments include new techniques for switching the cell between the stable states.

An optical lens system is disclosed which comprises a body of a nematic liquid crystal material placed in a variable electric or magnetic field. In response to variation of the field strength from zero to an upper limit, the focal length of the lens system changes continuously from a first focal length to a second focal length. The new lens system may be used, e.g., in cameras, telescopes, binoculars, projectors, and eyeglasses.

Variable focus liquid crystal lens system

A liquid crystal twist cell is disclosed in which the transmission characteristics may be conveniently controlled so as to produce a grey scale. The elastic constants of the crystal are maintained within a specified range to enable the convenient variation of transmission characteristics.

Liquid crystal twist cell with grey scale capabilities

An improved liquid crystal twist cell with significant reduction in the undesirable 'optical bounce' and off axis interference phenomena is described.

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New Providence, NJ, United States of America

Dwight W Berreman