Makoto Shiomi

Effect of molecular structure of chiral fluorinated compounds on spontaneous polarization of ferroelectric liquid crystals

The trans and cis isomers derived from chiral 1-trifluoromethyl-3-phenyl-2-propen-1-ol were prepared as chiral dopants of ferroelectric liquid crystals. They were doped to an achiral compound possessing a smectic C phase, and the induced spontaneous polarization of the mixtures was investigated. The observed spontaneous polarization for the trans isomer is larger than that for the cis isomer. The signs and values of spontaneous polarization were explained by a model which examined the fitness of two typical conformers possessing positive and negative spontaneous polarization to the zigzag conformation of molecules in the smectic C phase.

Ferroelectric liquid-crystal mixtures containing new chiral γ-lactone compounds

— New chiral γ-lactone compounds were developed as chiral dopants for ferroelectric liquid-crystal (FLC) mixtures. They were found to induce fast response times when they were doped into achiral liquid-crystal host mixtures. In addition, the effect of the molecular structure on the melting point and the helical twist properties in the nematic phase were investigated. Some FLC mixtures and their applications to FLC devices are described.

Novel optically active dopants for ferroelectric liquid crystals

Abstract Optically active compounds derived from 1-(4-substituted-phenyl)ethanols were evaluated as a dopant for ferroelectric liquid crystals. The effects of the restriction of the rotational freedom around the chiral center on the spontaneous polarization and the response time will be discussed.

New Miniaturized SAW Device in Low Frequency Range for SAW Video DOC System in Home VTR

A new dropout compensation method called the SAW video DOC system has been developed, corresponding to the stream of high density magnetic recording. The purpose is to improve the signal-to-noise ratio and the characteristic of dropout compensation for the palyback signal in home video tape recorders. A wide band SAW device in low frequency range of the key device in the system is miniaturized and practically can-packaged by newly developed techniques: the reduction of finger pairs, new ultraviolet curable polymeric resin and suppression of undesired wave response. In consequence, almost complete dropout compensatin and improvement of the 2.5 dB signal-to-noise ratio can be achieved in a playback video signal.