Cycle-down acceleration system for electrostatic copier - uses phosphorescent screen to produce high intensity light with control circuit for automatic initiation

摘要

The automatic preliminary cycling down system for an electrostatic copier includes a phosphorescent screen for uniformly illuminating the light sensitive member in its image zone. The light intensity is very much greater than that of the lamp for illuminating the image, within a light spectrum in which the light sensitive member releases internal charge carriers. There is also a control circuit for the preliminary cycling-down lamp which energises it so as to illuminate the image zone, only for a limited time, and is activated when the copier reaches a previously selected position. The control circuit initiates the illumination automatically before the light sensitive member is used to make a copy, and automatically reduces the cycling-down illumination when the copying cycle is commenced.