Liquid Crystal Matrix Display

It is shown that the electric-field-induced cholesteric-nematic phase transition of mixed liquid crystal possesses two important properties; (i) a sharp threshold in the scattering-vs.-voltage characteristic and (ii) an electrically controllable relaxation time. The mixed liquid crystal is composed of p-n-butoxybenzylidene-p'-cyanoaniline, p-n-octoxybenzylidene-p'-cyanoaniline, p-methoxybenzylidene-p'-n-butylaniline, and cholesteryl oleyl carbonate. A matrix panel with 3,500 display elements is constructed by using the mixed liquid crystal. When the matrix panel is scanned by a line-at-a-time addressing, the contrast of displayed characters is about 15: 1.