Driving method and apparatus for optical printer with liquid-crystal switching element

摘要

A driving method for an optical printer and an optical printer having a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof. The liquid-crystal light switching element is disposed between a light source and a movable photosensitive surface and controlled so as to at least one of transmit and block light from the light source to the photosensitive surface for enabling a printing operation. Voltages v1 and v2 are applied to the liquid-crystal switching element substantially in accordance with the equation <IMAGE> and the intensity of light from the light source incident on the liquid-crystal switching element is controlled so that incident light intensity during a period T2 is weaker than the incident light intensity during a period T1, where t0, t1, t2 and t3 represents times, T1 (=t1-t0) is the period during which a printing operation is effected, T2 (=t3-t2) is the period during which the photosensitive surface moves, v1 is the voltage which is applied to the liquid-crystal switching element during the period T1, and v2 is the voltage which is applied to the liquid-crystal switching element during the period T2.