| 摘要 |
<p>PURPOSE:To write a multilevel image in a short time by controlling both of light intensity and a writing time with the liquid crystal picture element of a liquid crystal shutter panel. CONSTITUTION:Light from a light source 1 is selected to be red, green or blue by a color selecting member 2. The light of the selected color is modulated by the liquid crystal shutter panel 3 composed of a large number of picture elements. The picture of each picture element of the liquid crystal shutter panel 3 is formed on the surface of a photosensitive member 6 through a picture forming optical system 5. At this time, plural light intensity levels are set and simultaneously, the maximum writing time is divided into n periods. When the number of the levels of the light intensity is defined as (k), a Lime Tn in the n-th period is set as k<(n-1)> times a time T1 in the first period, the combination of the writing period composed of one or plural periods with the light intensity level is changed to optically write the picture having gradation on tire photosensitive member 6.</p> |
