XEROGRAPHIC COPIER INCLUDING DEVELOPED IMAGE DENSITY CONTROL

摘要

A xerographic copier includes a control system to reduce the density of over-dense developed images after a period of non-use. After such a period, a signal from timer 84, in conjunction with a copy request signal, is effective to operate flip-flop 104 to cause low voltage photoconductor charging and to initiate a toner density test on a developed test patch on the photoconductor. Toner replenishment is at this time inhibited by an output from flip-flop 108. As copying continues, when a low density image is detected, as indicated by a low toner signal, the charging voltage is stepped up in stages by flip-flops 119 and 102 until the normal working voltage is reached. At that time, normal toner replenishment is started when required.