Hirofumi Katsuse

Four states of surface-stabilized ferroelectric liquid crystal with parallel rubbing

The orientational states of surface-stabilized ferroelectric liquid crystals with parallel rubbing were investigated by changing the pretilt angle of the aligning film. Four states, C1-uniform (C1U), C1-twisted (C1T), C2-uniform (C2U), and C2-twisted (C2T) states, were observed. The C1U and C2U states showed extinction positions, whereas the C1T and C2T states did not. The memory angle of the C1U state was larger than that of the C2U state for the respective cells. The molecular orientational model of these states is discussed with regard to the experimental results.

Ferroelectric liquid crystal device using the τ-VMIN mode

Abstract Ferroelectric liquid crystal (FLC) devices using the -Vmin mode were developed, combining FLC materials with negative dielectric anisotropy, the C2-uniform (C2U) orientational state and the “Malvern” drive schemes. The developed FLC materials in these devices showed the Vmin value under 35V, which is adequate to the drive voltage of ±40V. The C2U orientational state was found to be the preferred state for the -Vmin mode, and was obtained in FLC cells with medium pretilt aligning film. The FLC cells were driven by the Malvern drive schemes, achieving fast line address time (faster than 50μ sec/line), wide temperature range of driving (0∼40°C), high contrast (higher than 50:1) and drive voltage of ±40V.

A set of matrix addressing waveforms for the -Vmin mode in ferroelectric liquid crystal displays

Abstract We investigated the influence of waveforms on the -Vmin characteristic in ferroelectric liquid crystal materials with Δ<e0 and propose a set of drive waveforms showing a fast switching in matrix addressing scheme.

Dual Scanning Scheme for Ferroelectric Liquid Crystal Display

The dual scanning scheme (DSS) for ferroelectric liquid crystal displays (FLCDs) has been investigated. In DSS, two scanning electrodes are simultaneously selected and pixels on the two electrodes are switched to the black or white state in one unit time. We have investigated a DSS waveform set in which selected periods of two selected electrodes are duplicated. We found that the use of τ-Vmin mode FLC materials and the appropriate driving waveform set enables the simultaneous selection of two scanning electrodes and control of the FLC layers.