| 摘要 |
<p>An automatic development control for use in an electrophotographic apparatus. The control comprises a pair of substantially planar members forming a channel therebetween through which developer flows. One of the members is constructed such that an electrostatic charge pattern is periodically formed on the surface thereof, the charge pattern being developed by the attraction of toner thereto which toner has a charge opposite to that forming the charge pattern. The member on which the developed charge pattern is formed comprises a uniform, transparent conducting substrate covered with a transparent insulating layer on top of which is deposited a set of spaced-apart, opaque and electrically conducting fingers. Thus, said one of the members comprises alternate opaque and transparent areas. By grounding the electrically conducting fingers which are all interconnected and by driving the substrate alternately positive and negative, toner is deposited on the transparent areas during the application of one half cycle of voltage and during the following half cycle the toner is deposited on the opaque fingers and scavenged from the transparent areas. The optical density of the toner deposit is directly related to the toner concentration in the developer. Said one of the members then forms part of the toner concentration control.</p> |
