JPS5764759A - Developing device - Google Patents

Abstract

PURPOSE:To achieve good developing by applying DC bias voltage for forcing charge to a toner to the inside wall of a developig vessel, and at the same time, applying AC bias voltage for a countermeasure against fog from the backside of a fur in order to apply an AC electric field to the fur of a fur brush developig roller. CONSTITUTION:A fur brush developing roller 4 whose part contacrs the surface of a sensitive body 3 is contained in a developing vessel 1 connected with a toner containing box 2. The roller 4 fixes a short fur body 7 to a soft core body 5 through conductive bonding agent 6. And in the toner feeding port of the toner containing box 2, a toner supply roller 8 is provided and a toner 9 is supplied in the developing vessel 1. At the bottom walls of the developing vessel 1, an electrode 11 in the sheet shape to which DC bias voltage 10 for forcing charge to a toner is provided near by or on a contacting condition to the fur body 7 of the developing roller 4, and further, it is arranged that AC bias voltage 12 for countermeasures against pullover is applied from the backside of the fur body 7 so as to apply AC electric field to the fur body 7 on the developing roller 4.