An OCB device comprises upper and lower substrates, each provided with an alignment layer. A liquid crystal layer is provided between the substrates. The lower substrate has a low pre-tilt in regions A and C, so that an H-state is stable in these regions when no voltage is applied across the liquid crystal layer. Region B has a high pre-tilt on the lower substrate, so that a HAN state is stable in region B under zero applied voltage. When a voltage is applied across the liquid crystal lever, a V-state is formed at the interface between the HAN-state and the H-states. This V-state then displaces the H-states in regions A and C. The high pre-tilt region, region B, is acting as a nucleation region. The V-state forms at a lower applied voltage than if the nucleation region is not provided.
A pi-cell liquid crystal device comprises a nematic liquid crystal layer (17) disposed between alignment layers (14,15) which provide a pretilt such that, at a zero applied field, the energy of the H-state is less than the energy of the V-state, which is less than the energy of the T-state. A drive arrangement (18) switches the pi-cell by applying a first electric field, at which the energy of the V-state is less than the energy of each of the H-state and the T-state, or a second smaller electric field, at which the energy of the H-state is less than the energy of each of the V-state and the T-state. The T-state may thus be avoided while maintaining high switching speeds.
A method for providing a high-response and wide-viewing-angle liquid crystal panel capable of causing a transition of liquid crystal, called the OCB mode, into a bend configuration in a short time, by providing a period in which a potential difference higher than that in a normal image display period is continuously applied between gate lines and opposing electrodes or between pixel electrodes and the opposing electrodes of a liquid crystal panel.
An optically compensated birefringence mode liquid crystal display device includes first and second substrates facing and spaced apart from each other, a liquid crystal material layer between the first and second substrates, the liquid crystal material layer having a splay state when a voltage is not applied and having a bend state when a transition voltage is applied, a first compensation film on an outer surface of the first substrate, a first polarizing plate on the first compensation film, a second compensation film on an outer surface of the second substrate, and a second polarizing plate on the second compensation film, wherein the liquid crystal material layer in the splay state has a first retardation value (R1) satisfying according to: 1.35<R1/.lamda.<1.75 the liquid crystal material layer in the bend state has a second retardation value (R2) according to: 0.5<R2/.lamda.<0.7 when a white voltage for a white image is applied, and a third retardation value (R3) according to: 0.1<R3/.lamda.<0.15 when a black voltage for a black image is applied.
Disclosed is a multi-domain liquid display preventing deviation of a domain boundary using a patterned spacer. The present invention includes a first substrate having a plurality of pixel areas defined by a plurality of data and gate lines and a plurality of pixel electrodes formed in the pixel areas, respectively, a second substrate having a black matrix layer cutting of lights from a portion excluding the pixel areas and an alignment boundary and a color filter layer realizing colors, a first alignment layer formed on the first or second substrate so as to have at least two different alignment states centering around the alignment boundary in each of the pixel areas, and a patterned spacer formed between the first and second substrates at a portion of the alignment boundary.
A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates; and means for applying a voltage across the liquid crystal layer. A first region of the liquid crystal layer is an active region for display and a second region of the liquid crystal layer is a nucleation region for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p).sub.A in the first region of the liquid crystal layer and has a second value (d/p).sub.N different from the first value in the second region of the liquid crystal layer. The value (d/p).sub.N of the ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material in the second region of the liquid crystal layer is selected such that, when no voltage is applied across the liquid crystal layer, the liquid crystal state stable in the second region of the liquid crystal layer is topologically equivalent to the desired liquid crystal state.
