| 摘要 |
<p>1,246,847. Electro-optical element containing cholesterol and like compounds. R.C.A. CORPORATION. 18 Nov., 1968 [13 Dec., 1967], No. 54586/68. Heading C2U. [Also in Division H4] A light valve or display device comprises a mixture of at least one nematic liquid crystal of the type that exhibits non-destructive turbulent motion when an electric current of sufficient magnitude is passed therethrough i.e. upon the application of a D.C. or low-frequency electric field the single-phase homogeneous molecular solution separates into two phases causing incident light to be scattered, with at least one member of the group consisting of cholesterol, cholesterol derivatives and cholesteric liquid crystals. The mixture preferably comprises cholesteryl oleate and cholesteryl chloride, and at least one member of the group consisting of anisylidene-p-aminophenylacetate, p n - butoxybenzylidene - p - aminophenylacetate and anisylidene-p-aminophenylbutyrate. The mixture exhibits storage of its. light scattering, emulsion-like state after removal of the electric field initiating the state. To return the mixture to its transparent state a relatively high-frequency A.C. field is applied to the mixture. The Specification includes a table of alternative nematic liquid crystals, cholesterol derivatives and cholesteric liquid crystals, and describes various mixtures by weight.</p> |
