| abstract |
This disclosure is directed to articles of manufacture, chiefly display devices, containing encapsulated cholesteric liquid crystals which change color or shade of color not only upon application of an electric potential but also upon removal of the field. The image produced has a comparable outline to that of the path of the electric field. Three chromatic states are evident, the normal color (before the electric potential is applied), the color given off when the electric field is applied, and the color observed when the electric field is removed. All three chromatic states are readily discernible from one another. The encapsulation of the cholesteric liquid crystal provides an unusual advantage regarding electric field behavior because the third chromatic state (electric potential removed) has a much greater longevity with the encapsulated material versus unencapsulated material of identical composition. Other advantages are also discussed. |