Liquid crystal device for generation and fast switching of high contrast images

A liquid crystal device comprising a sandwich cell with a pair of substrates forming a cavity there between and a liquid crystal bulk layer arranged in between said substrates in said cavity, wherein at least one of the substrates is transparent, and wherein the liquid crystal bulk is antiferroelectric liquid crystal (AFLC) material with high molecular tilt, exhibiting a continuous (second order) field-induced antiferroelectric to ferroelectric transition (AF-F) transition.

An electro-optic device including:

• a liquid crystal material comprising antiferroelectric liquid crystals with large molecular tilt θ of about 45° degrees;
• tow flat substrates, wherein the liquid crystal material is disposed between the substrates, wherein the substrates have electrode pattern on their inner surfaces facing the liquid crystal wherein the liquid crystal molecules are oriented parallel to the substrates in a HAF texture;
• tow crossed polarizers, arranged so that in a field off condition impinging light is not passing through the device due to the isotropic optical properties of the antiferroelectric liquid crystal aligned in HAF texture, whereas an applied electric field induces a second order transition of the optically isotropic antiferroelectric (AF) state to a ferroelectric (F) state which is birefringent enabling the transmission of light wherein the field-induced continuous switching between the optically isotropic antiferroelectric state and the birefringent ferroelectric state enables the generation and fast switching of high contrast as well as generation of grey scale levels.