BISTABLE LIQUID CRYSTAL DISPLAY DEVICE

A bistable liquid crystal display device comprises: a first cell wall ( 1 ) and a second cell wall ( 1 ') enclosing a layer of a nematic liquid crystal material ( 5 ) and electrodes ( 2, 2 ') for applying an electric field across at least some of the liquid crystal material ( 5 ). A first alignment structure is provided on an inner surface of the first cell wall ( 1 ), comprising a grating ( 3 ) which tends to induce adjacent molecules of the liquid crystal material ( 5 ) to adopt a uniform planar alignment substantially without pre-tilt. A second alignment structure is provided on an inner surface of the second cell wall ( 1 '), comprising an array of posts ( 4 ) or holes which tend to induce adjacent molecules of the liquid crystal material ( 5 ) to adopt a uniform planar alignment with pre-tilt. The surface of the second alignment structure has a higher anchoring strength than does the surface of the first alignment structure, and two stable molecular configurations of the liquid crystal material ( 5 ) can exist after suitable electrical signals have been applied to the electrodes ( 2, 2 '). Other aspects of the invention provide a method of manufacturing the device and a method of addressing the device.