| 摘要 |
<p>PURPOSE:To obviate the generation of a problem such as degraded memory characteristic even after long-period driving by impressing the periodic voltage waveforms which do not generate a DC component within a specified period to a ferroelectric liquid crystal in the time zone exclusive of the time zone for driving an optical shutter array for the purpose of printing. CONSTITUTION:The ferroelectric liquid crystal of a printing device of an electrophotographic system of the type in which a liquid crystal light modulating element is used as the optical shutter array and images are written on a photosensitive body by exposing said body with the light controlled by the optical shutter array has high-speed responsiveness and memory characteristic but the memory characteristic degrades with the deterioration of the liquid crystal when the DC component is impressed to the liquid crystal. The selection time is, thereupon, so selected as to be longer than at least the response time of the liquid crystal in the time zone of printing in case of driving the ferroelectric liquid crystal element. In addition, the periodic voltage waveforms which do not generate the DC component in the specified period are impressed to the time zone when the printing is not executed. For example, 0.5 second of the time zone when the printing is not executed is provided after driving for one page is executed.</p> |
