Sharp Kabushiki Kaisha Corporation

Other

The Secretary of State for Defence in Her Britannic Majesty's Government

Diana Cynthia Ulrich

Michael John Towler

Paul Bonnett

Masaaki Kabe

Akira Tagawa

Craig Tombling

Akira Sakaigawa

Harald Reinhart Bock

A liquid crystal device comprises pixels which are switchable between a white state and a black state. Spacers are disposed in gaps between the pixels and are birefringent such that the spacers have the same optical properties as liquid crystal in the black state. For example, the spacers may have the same retardation as the liquid crystal layer with an optic axis fixed in the direction of the optic axis of the liquid crystal when in the black state.

Liquid crystal device

A liquid crystal display element is formed by providing a liquid crystal layer made of ferroelectric liquid crystal material between electrode substrates. One of the electrode substrate is composed of a substrate, electrodes, an insulating film, and an alignment film, while the other substrate is composed of a substrate, electrodes, an insulating film, and an alignment plate. The alignment film is formed by mixing a substance with ionic bond in an alignment film material and thereafter applying the mixture on the paired substrates on each of which the electrodes and the insulating film are provided. With this arrangement, ions are eluted from the alignment films thus formed into the liquid crystal layer, thereby becoming dispersed therethrough homogeneously. This remarkably reduces influences of display history, and half-tone display with excellent response characteristics can be realized, being not affected by display history.

Liquid crystal display element and manufacturing method thereof

A method of addressing a liquid crystal device having a plurality of scanning electrodes and a plurality of data electrodes defining a plurality of pixels at the intersections between at least one of the plurality of scanning electrodes and at least one of the plurality of data electrodes, the method comprising applying one frame of a scanning signal to one of the plurality of scanning electrodes, applying a data signal to at least one of the plurality of data electrodes, one frame of the scanning signal comprising n strobe portions, where n is an integer greater than 1, for co-operation with the at least one data signal to address one of the plurality of pixels, and at least one blanking portion, the number of blanking portions not exceeding (n&minus;1).

Liquid crystal device and method of addressing liquid crystal device

Reduction of ionic memory effect in ferroelectric liquid crystal material. A method of reducing the effects of ionic memory in a ferroelectric liquid crystal (FLC) material to which a switching pulse is applied comprises the steps of: a) adding an ionic dopant to the FLC material, the ionic dopant providing ions having a fast response to an applied electric field; and b) following said switching pulse by a first pulse of opposite polarity to said switching pulse, in such a way that said first pulse reduces any ionic reversal field created by said switching pulse, but does not destabilize the state to which the FLC material is switched by said switching pulse.

Reduction of ionic memory effect in ferroelectric liquid crystal material

A light modulating device comprises a plurality of data electrodes, a plurality of strobe electrodes, pixels at the intersections of the strobe and data electrodes, and addressing means for supplying data signals to the data electrodes in successive data selection periods and for supplying strobe signals to the strobe electrodes to set the transmission levels of the pixels in dependence on the data signals supplied to the pixels during each data selection period. Each pixel comprises a pair of subelements, and the addressing means is arranged to address the subelements of the pair by 1:3 spatial dither and to supply different strobe signals to each of the subelements during different bits of 1:1 spatial or temporal dither within the same data selection period. The transmission level of each subelement is determined by the data signal applied to the subelement in the data selection period in association with the strobe signal applied to the corresponding spatial or temporal dither bit.

Light modulating devices

A ferroelectric liquid crystal display panel comprises an addressable matrix of pixels and an arrangement for selectively addressing each pixel within a series of addressing frames in order to vary the transmission level of the pixel relative to the transmission levels of the other pixels. The addressing arrangement utilizes a temporal dither (TD) addressing scheme for addressing each pixel within each frame with different combinations of temporal dither signals applied to separately addressable temporal bits within the frame to produce different overall transmission levels. In order to limit the perceived errors at the transitions between different grey levels the TD addressing scheme is arranged to address a first pixel with a first combination of TD signals to produce a first grey level and to address a second pixel with a second combination of TD signals, which differs from the first combination of TD signals, to produce the same first grey level such that, during a transition between the first grey level and a second grey level, a transient in one direction in the transmission level of the first pixel is at least partially compensated for by a transient in the opposite direction in the transmission level of the second pixel.

A ferroelectric liquid crystal display comprises an addressable matrix of pixels 7 and addressing circuitry comprising a data signal generator 14 for applying data signals to column electrode tracks 4.sub.1, 4.sub.2. . . . . 4.sub.n and a strobe signal generator 15 for applying strobe signals to row electrode tracks 5.sub.1, 5.sub.2. . . . . 5.sub.m in order to selectively switch the pixels 7. In order to provide a large number of well defined grey levels, the addressing circuitry includes spatial and/or temporal dither control circuits for addressing separately addressable subpixels of each pixel 7 with different combinations of spatial dither signals and/or for addressing at least part of each pixel with different combinations of temporal dither signals applied to separately addressable temporal bits corresponding to subframes of different periods to produce a plurality of different transmission levels. Furthermore at least a part of each pixel is switchable between different states by means of on and off switching signals, at least one bit of some of the pixels being switchable into intermediate states, including at least one error producing analogue state, by intermediate switching signals in order to produce intermediate overall transmission levels, and such switching being controlled so that periods in which at least part of the pixel is in an error producing analogue state alternate with periods in which the part is in a substantially error free state in order to limit the propagation of transmission errors.

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Oxford, United Kingdom

Diana Cynthia Ulrich