Abstract: An image forming apparatus includes a detachably mountable developing device including a developer container, a developer carrying member, a feeding member, provided in contact with the developer carrying member, for supplying the developer to the developer carrying member, and a developer regulator; and a voltage device capable of applying to the developer carrying member and the developer regulator respective voltages different from each other. The image forming apparatus carries out, when a fresh developing device is mounted, an initial operation in which the developer carrying member is rotated. In the initial operation, the voltage device applies, to at least one of the developer carrying member and the developer regulator, a voltage for the initial operation which is different from the voltage for normal image forming operation, so as to urge a material applied to the developer carrying member in the fresh developing device toward the developer regulator from the developer carrying member.

Abstract: A copier/printer that employs a plurality of roll media includes a paper path monitored by a plurality of dual use sensors. The first use of the sensors is to initialize the lead edge of each media roll and the second use of the sensors is as jam detectors. When media is coming from a position lower than other media rolls, each sensor along the paper path is used in a timing sequence to monitor the media lead edge and indicate a jam if the media does not reach particular sensors in accordance with the timing sequence.

Abstract: An image forming apparatus is formed by providing a latent image-bearing member for holding an electrostatic image thereon and a toner-carrying member for carrying a prescribed magnetic toner comprising a binder resin and magnetic powder and having a particle size distribution including 12% by number or more of magnetic toner particles of 5 microns or smaller, 33% by number or less of magnetic toner particles of 8-12.7 microns and 2% by volume or less of magnetic toner particles of 16 microns or larger so as to provide a volume-average particle size of 4-10 microns. At the developing station, an alternating bias voltage comprising a DC voltage and an unsymmetrical AC voltage in superposition is applied between the toner-carrying member and the latent image-bearing member to provide an alternating bias electric field comprising a development-side voltage component and a reverse-development side voltage component.