Liquid Crystal Shutters for Printers

Abstract

This paper describes two-frequency driven liquid crystal shutters (LCSs) for electrophotographic printers utilizing liquid crystals which show dielectric relaxation phenomenon in the audio-frequency range. A “one steady state operation” concept is adopted to realize high speed response time. The ECB mode is used for optical switching. Properties required for the liquid crystal materials and the practical uses of the materials are explained. Optical switching is performed by combining an initializing signal, a state-changing signal and a state-holding signal. Two examples of multiplex drive waveforms and their optical responses are given. Finally, specifications for electrophotographic printers using two-line multiplex-driven LCSs are shown.

Key Words:

• liquid crystal
• nematic phase
• dielectric relaxation
• two-frequency addressing
• liquid crystal shutter
• printer