Poly-layer liquid crystal display device

Claim 1

A liquid crystal display device, comprising an array of at least three plates, two of said plates being end plates and the remaining plates being intermediate plates, said plates taken in pairs forming cells one less in number than the number of said plates, a layer of nematic liquid crystal material of positive dielectric anisotropy in said cells, opposed surfaces of the pairs of plates having electrode means thereon for forming characters a vector from the bottom to the top of any of said characters defining a reference direction, a polarizing device at the exterior face of each end plate in said array, successive liquid crystal layers being considered alternately even and odd, the two plate faces in contact with each of said liquid crystal layers having surface orientation directions for forming the liquid crystal molecules in said layer into a helix with a twist of about 90°, said twist being in one rotational direction for the even layers and in the opposite direction for the odd layers, the two faces of each intermediate plate in said array being surface-oriented in approximately anti-parallel directions, that is, at approximately 180° to each other, one of said end plates being that through which said device is to be viewed and being termed upper end plate and each of said cells thereby being formed of an upper and lower plate, said surface orientation directions being regarded as vectors, the angle from said reference direction to said surface orientation direction on each of said upper plates being approximately 45° and to said surface orientation direction on each of said lower plates being approximately 135°, said electrodes being connectable to an exterior voltage source.