| 摘要 |
PURPOSE:To photoengrave a master with excellent picture quality by stopping a toner feed control function based upon a reference latent image to inhibit toner feed when a switch is set up to a master photoengraving for a stencil printer. CONSTITUTION:In case of obtaining a low density copy in order to photoengraving the master for a photosensitive stencil printer, a switching means 45 is switched, a glid electrode 43 in an electrostatic charger 2 is earthed through only one varistor 44a and initial charging potential on the surface of a photosensitive drum 1 is held at a level lower than that of normal copying. A mode signal M2 is sent from the switching means 45 to a toner feed control device 51, but a signal S from a developing concentration detecting part 31 is interrupted by a stopping means, so that toner feeding to a developing device is forcedly stopped. Consequently, excess feed of toner to the developing device can be surely suppressed and toner density in a dot plate printing mode can be properly held. |
