Organic compounds -- part of the class 532-570 series – Organic compounds – Nitrogen attached directly or indirectly to the purine ring...
Patent
1986-02-06
1988-02-16
Gron, Teddy S.
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitrogen attached directly or indirectly to the purine ring...
544242, 544335, 25229901, 2522995, 25229961, 350350R, 350350S, C09K 1934, G02F 113, C07D23926
Patent
active
047256885
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention is related to a new liquid crystal compound useful for electric optical elements, utilizing the response of a ferroelectric smectic liquid crystal to an electric field.
BACKGROUND OF THE INVENTION
Liquid crystals have been adapted already as the electric optical elements for many kinds of devices such as display devices, shutter alley for a printer, shutters for cameras, and are actuated in the display of watches and table calculators.
Most of the liquid crystal display elements presently actualized are elements utilizing the dielectric orientation efficiency of a nematic liquid crystal or a cholesteric liquid crystal. But, concerning the expected requirements for display elements with many picture elements, there are such problems as, an insufficient response ability, a contrast not able to obtain the necessary drive margin, and an insufficient visual angle characteristic. Therefore, extensive research and development of the TFT panel or MOS panel that forms the switching element in each picture element is being carried out.
In this state, Clark et al (U.S. Pat. No. 4,367,924) conceived new a liquid crystal element with new display principle, utilizing the smectic phase, which cures the above defects of the liquid crystal element. The explanation of this new element is as follows;
FIG. 1 is a typical diagram of the smectic C* phase or the smectic H phase. The liquid crystal is composed of molecule layers 1, and in each of the layers, the average direction of the molecule axis is inclined o degrees in the vertical direction to the layers. Meyer et al teaches in a thesis titled "Ferroelectric liquid crystal" of "Physical Journal" (Le Journal de Physique Vol. 36, March, 1975 PPL-69 to L-71), that, the Smectic C* or H phase composed of an optically active molecule generally has an electric dipole density P and is ferroelectric. This dipole density P is vertical to the molecule direction n, and is parallel to the layer surface of the smectic. What they teach is adaptable to the smectic H phase, but in the H phase, the viscosity to the rotation around the axis vertical to the layer, becomes large. The existence of electric dipoles in these chiral smectic liquid crystals gives a stronger coupling force to the electric field, than that of dielectric anisotropy. Furthermore, it can be said that this coupling force has a polarity characteristic, in the sense that the favorable direction of P is the parallel direction to electric field E, and so, by reversing the direction of the applied electric field, the direction of P can also be reversed.
Therefore, by reversing the electric field, as shown in FIG. 2, the direction of the molecule can be controlled by moving the molecule along the cone (the angle 2.degree. of this cone is hereinafter referred to as the cone angle). Then, by detecting the variation of the average molecule axis direction with two polarizers, the liquid crystal element can be utilized an electric optical element.
Because this electric optical element which utilizes the response of the Smectic C or H phase to an electric field, holds a coupling force between its spontaneous polarization and the electric field, a force which is 3 or 4 orders larger than the coupling force of dielectric anisotropy, compared to TN type liquid crystal element, this electric optical element has an efficient high speed response characteristic, and it can also have a memorizing characteristic by selecting the appropriate orientation control; thus it is expected to be adapted as a high speed optical shutter or as a display with a large capacity for information.
Meanwhile, many kinds of chiral smectic liquid crystal material having a ferroelectric characteristic have been studied and synthesized. The first synthesized ferroelectric liquid crystal is called DOBAMBC.
p-Decyloxybenzilidene-p'-amino-2- methylbutyl cinnamate, and many compounds of this series of liquid crystal compositions, shown in the following formula, have been synthesized for research concerning ferroelectric
REFERENCES:
patent: 3997536 (1976-12-01), Boller et al.
patent: 4180475 (1979-12-01), Schadt et al.
patent: 4309539 (1982-01-01), Boller et al.
patent: 4311610 (1982-01-01), Zaschke et al.
patent: 4389329 (1983-06-01), Boller et al.
patent: 4402849 (1983-09-01), Krause et al.
patent: 4410445 (1983-10-01), Baur et al.
patent: 4462923 (1984-07-01), Boller et al.
patent: 4564694 (1986-01-01), Hirai et al.
patent: 4576732 (1986-03-01), Isogai et al.
patent: 4613209 (1986-09-01), Goodby et al.
patent: 4657695 (1987-04-01), Saito et al.
Demus, D., et al., Flussige Kristalle in Tabellen II, Veb Deutscher Verlag fur Grundstoffindustrie, Leipzig, pp. 342-400, (1984).
Zaschke, H., Advances in Liquid Crystal Research & Applications, Bata, L., Ed., Pergamon Press, Oxford, pp. 1059-1074, (1980).
Gray, G. W., et al., Liquid Crystals & Plastic Crystals, vol. 1, John Wiley & Sons, New York, pp. 137-143, (1974).
Harada Takamasa
Suenaga Hitoshi
Taguchi Masaaki
Adams Bruce L.
Gron Teddy S.
Seiko Instruments Inc.
Teikoku Chemical Industry Co., Ltd.
Wilks Van C.
LandOfFree
Liquid crystal compound does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid crystal compound, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid crystal compound will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2221893