| 摘要 |
PURPOSE:To obtain an inexpensive shutter head which has high reliability by providing ferroelectric liquid crystal with three periods, i.e. a selection period, a nonselection period, and a relaxation period, and driving the liquid crystal. CONSTITUTION:A voltage waveform 18-i (i=1,2...8) consists of the relaxation period TR wherein the distribution of ion materials in the liquid crystal in uniformed, the selection period Tj-i (1<=i<=8) wherein the light transmissivity of shutter picture elements is controlled depending upon a voltage applied to signal electrodes, and the nonselection period Tj-k (1<=k<=8 and knot equal to i) wherein the shutter picture elements are placed in a low transmission state without depending upon the voltage applied to the signal electrodes. In the relaxation period TR, the voltages are applied to common electrodes and the signal electrodes so that the voltage applied to the shutter picture elements in a DC voltage or an AC voltage which varies positively and negatively. In the selection period, the positive or negative voltage is applied to the shutter picture elements to select a high and a low transmission state, thereby writing a signal on a photosensitive drum optically. In the nonselection period, the voltage is applied to the common electrode so that the shutter picture elements goes to the low transmission state without depending upon the voltage applied to the signal electrodes.
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