| 摘要 |
<p>PURPOSE:To set an erased area finely by providing a liquid crystal shutter which has light transmission control electrodes split and arrayed breadthwise between an erasing light source and a photosensitive body and setting a light transmission and a light nontransmission voltage for each control electrode selectively. CONSTITUTION:An eraser 24 consists of a rod type cathode-ray tube 240 which is long at right angles to the paper surface,a reflecting mirror 242 whose section is semielliptic, a filter 243 which matches the spectral distribution of projection light with the characteristic spectrum of a photosensitive body, a liquid crystal shutter 244, and a liquid crystal driver 245. The shutter 244 is formed by arraying light transmission and nontransmission control electrodes in two arrays (arrays A and B) along the axis of the photosensitive drum, i.e. in the breadthwise direction of the photosensitive body at a pitch of 4 dots/mm. Thus, the light transmission set voltage and light nontransmission set voltage are applied to the respective control electrodes by an eraser control unit 241 to set the erased area more finely.</p> |
