Abstract: A developing device has a first toner carrier which carries, on an outer peripheral surface, toner to be fed to an electrostatic latent image formed on an image carrier and which is arranged out of contact with the image carrier; a second toner carrier which carries, on an outer peripheral surface, toner to be fed to the electrostatic latent image and which is arranged out of contact with the image carrier; and a developer carrier which carries a developer made up of toner and carriers and which feeds the toner to the first toner carrier and the second toner carrier. The toner carried by each of the first toner carrier and the second toner carrier is caused to adhere to the electrostatic latent image formed on the image carrier by application of an AC bias voltage to each of the first toner carrier and the second toner carrier.

Abstract: A developing device having: a plurality of toner support members for supporting toner on their peripheral surfaces, the plurality of toner support members being arranged in a direction of rotation of an image support member out of contact with the image support member; and a developer support member for supporting a developer containing toner and carriers and supplying the toner to the plurality of toner support members; wherein the plurality of toner support members have dielectric layers on their surfaces, the dielectric layers satisfying a condition d1/?1>d2/?2; and wherein the first toner support member and the second toner support member are connected to a single power source.

Abstract: A developing device including a housing, toner a developing roller, and a feed roller in pressure contact with the developing roller so as to form a nip portion and which feeds toner to the developing roller. The developing device including a feed stabilizing member contacting a lower portion of the feed roller so as to form a second nip portion and restricting toner feed quantity. The feed stabilizing member extending from a generally triangular-shaped first region below the first nip portion up to one side of the nip portion opposite to the first region side. The developing device further including a toner circulation path for pushing back toner from the first region through below the feed stabilizing member to a second region on the one side opposite to the first region side with an aid of pressure of toner that tends to accumulate in the first region.

Abstract: A developing device having a plurality of toner carrying members for carrying toner on their outer peripheral surfaces, the plurality of toner carrying members being placed along a rotating direction of an image carrying member and out of contact with the image carrying member; and a developer carrying member for carrying a developer composed of toner and carriers and for supplying the toner to the plurality of toner carrying members. In the developing device, AC bias voltages are applied to the toner carrying members so as to cause the toner carried by the toner carrying members to stick to an electrostatic latent image formed on the image carrying member by the effect of electric fields induced by a voltage of the electrostatic latent image and the AC bias voltages applied to the toner carrying members.

Abstract: A developing device includes a housing in which nonmagnetic one-component toner is housed, a developing roller which horizontally extends in an opening of the housing, and a feed roller which is set in the housing in pressure contact with the developing roller so as to form a nip portion and which feeds toner to the developing roller. The developing device also includes a feed stabilizing member which is in contact with a lower portion of the feed roller so as to form a second nip portion, and which restricts toner feed quantity. The feed stabilizing member is provided so as to extend from a generally triangular-shaped first region below the first nip portion up to one side of the nip portion opposite to the first region side.