Abstract: An image forming device for connection to first and second external devices, including a control unit having an alternate operation mode for performing alternating communication with external devices by switching communication at a predetermined cycle. During communication with one of such external devices, the control unit enables reception of commands and/or a print-start signal from that external device and refuses reception of commands and a print-start signal from another external device. When communication is changed over from one external device to another external device, the control unit provides an interval in which reception of commands and a print-start signal from both external devices is refused for a predetermined period of time.

Abstract: A developing apparatus having a resilient developing roller for developing an image with a single-component toner includes a contacting mechanism for moving the developing roller into contact with a surface of an image carrier for developing the image and moving the developing roller in a forward direction at substantially the same speed as the image carrier. The width of a developing nip and a depth of bite between the image carrier and developing roller is set such that the traveling speed of the local portion of the developing roller that contacts the image carrier gradually decreases from a point at which contact starts and then gradually returns to the original speed. The width of the developing nip is at least 4 mm, the hardness of the developing roller is 20-40 degrees, the diameter of the developing roller is 40-100 mm, and the bite depth is equal to or greater than {fraction (1/100)} the radius of the developing roller.

Abstract: In a fixing device wherein a toner image formed on a copying paper by an electrophotographic copying machine is fixed while the copying paper is maintained in contact with the periphery of a heated fixing roller. Pressure is applied to the copying paper by a pressure applying device including an endless belt supported by a pair of spaced rollers which are mounted on a slidable plate. The slidable member is normally clamped at an operating position by a clamping member. When the clamping member is released, the slidable plate can be slid laterally to separate the endless belt from the fixing roller thereby enabling removal of jammed copying paper, exchange, repair and inspection of various elements of the fixing device.

Abstract: In a photosensitive element including an electroconductive layer, a photoconductive layer manifesting persistent internal polarization and a highly insulative layer and utilized in the method of electrophotography wherein a first electric field is applied to deposit a charge of one polarity on the surface of the highly insulative layer, and a second field is applied to deposit a charge of the opposite polarity concurrently with the projection of a light image to form a latent image on the surface of the highly insulative layer, there is provided a vapor deposited layer at the interface between the photoconductive layer and the highly insulative layer which consists of a mixture of a first Se-Te alloy having a percentage of Te therein such that it is a highly photosensitive material and a second Se-Te alloy having a percentage of Te therein such that it has high charge trapping capability.

Abstract: In apparatus for stripping receptor paper away from the photosensitive drum of an electrophotographic machine after transfer printing, there are provided a stripping roller having a frictional band near its one end and urged against the photosensitive drum, and a stripping pawl having a pointed end adapted to engage the leading edge of the receptor paper for stripping the receptor paper and urging the same against the frictional band on the stripping roller.