A CHIRAL NEMATIC LIQUID CRYSTAL LIGHT SHUTTER

摘要

A light shutter comprises a cell (301) comprising a first substrate (90) and a second (90) substrate spaced apart from the first substrate by a distance, and a layer (1201) between the substrates containing a chiral nematic liquid crystal (10) whose pitch is less than the distance between the substrates. A surface of the layer adjacent the second substrate comprises a monolayer of protrusions (114) projecting into the layer, the centre-to-centre distance (900) of the protrusions being greater than the pitch. In the absence of an electrical field, the chiral nematic liquid crystal aligns in polydomains (20, 21) in the layer and the protrusions stabilize the polydomains over time, and the cell prevents visual access through the shutter. In the presence of an electrical field the liquid crystal aligns with a common identifiable alignment (11) in one axis and the cell provides visual access through the shutter.