Light valve imaging apparatus and method having supplemental exposure control
Method for driving liquid crystal element employing ferroelectric liquid crystal Patent #: 4508429
ApplicationNo. 06/629045 filed on 07/09/1984
US Classes:347/235, Scan synchronization (e.g., start-of-scan, end-of-scan)347/237, Driving circuitry349/187, NOMINAL MANUFACTURING METHODS OR POST MANUFACTURING PROCESSING OF LIQUID CRYSTAL CELL349/37, Polarity based driving358/300, Electrostatic or electrolytic359/276Amplitude modulation
ExaminersPrimary: Goldberg, E. A.
Assistant: Foster, Patrick W.
Attorney, Agent or Firm
International ClassG06K 15/12 (20060101)
Foreign Application Priority Data1983-07-08 JP
AbstractA 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 ##EQU1## 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.