Patent ID: 7430030

Claim:
A bistable nematic liquid crystal display device comprising: a first cell wall and a second cell wall enclosing a layer of nematic liquid crystal material; at least one electrode on each cell wall for applying an electric field across at least some of the liquid crystal material; a first surface alignment on an inner surface of at least part of the first cell wall for inducing adjacent molecules of the liquid crystal material to adopt a desired orientation; and a layer of solid particles secured over the first surface alignment on an inner surface of the first cell wall in which the solid particles bond with surrounding liquid crystal molecules in such a manner that it stabilizes a locally induced alignment of the liquid crystal material; whereby the nematic liquid crystal material will adopt a first stable molecular configuration in response to a first pulse of a unidirectional electric field of suitable magnitude and duration and will adopt a second stable molecular configuration in response to a second pulse of unidirectional electric field of suitable magnitude and duration and opposite polarity to the first pulse, the second configuration being different from the first configuration.