US Patent 8199295 Liquid crystal device including an alignment grating with breaks therein

This invention relates to a liquid crystal device wherein the surface profile of a surface alignment grating stabilises at least one stable state. The invention involves the introduction or breaks (34, 36, 38) or discontinuities into the grating (10) to divide the grating into a plurality of groove segments. The breaks are discontinuities in the grating in the groove direction, the grating having substantially the same groove direction on each side of the break. The introduction of breaks prevent free movement of defects along the groove of the grating and therefore help to stabilise the desired liquid crystal configuration, either a Defect state or a Continuous state. Suitable breaks involve gaps (34) in the groove ridges (30), necks (36) between the groove ridges (30) and slips or relative displacement (38) of the grating.