Patent ID: 7633586

Claim:
A display comprising a display device which is controllable to provide image display and a first liquid crystal device having at least one liquid crystal layer whose molecules are switchable between a first state providing a first viewing angle range and a second state providing a second viewing angle range which is within and smaller than said first viewing angle range, said first liquid crystal device being arranged, when said liquid crystal molecules are in said second state, to block at least partially light propagating towards a part of said first viewing angle range outside said second viewing angle range, said first liquid crystal device comprising at least one alignment surface and said at least one liquid crystal layer being in contact with said at least one alignment surface, each said at least one alignment surface at each said at least one liquid crystal layer comprising a uniform non-patterned alignment surface, wherein said first liquid crystal device is arranged, when said liquid crystal molecules are in said second state, to superimpose, on light propagating towards said part of said first viewing angle range, a spatially varying amplitude constituting an obscuring pattern for rendering unintelligible an image displayed by said display device.