Abstract: A skive for a pressure roller fuser separates a receiving sheet that has a tendency to stick to one of the rollers in the fuser. The skive includes a finger having a tip which is spring urged against the roller. A mount for the finger permits the tip to move along the periphery of the roller in response to a difficult-to-separate sheet. The skive continues to attempt to separate the sheet without further pushing the tip into the roller. A guide surface on the finger continues to be directed by the mount toward a desired post-fuser path for the receiving sheet despite movement of the tip along the roller.

Abstract: A fuser for fixing toner images to a receiving sheet includes pressure and fusing rollers which are separated during idle. In response to a run signal, the temperature of the fusing roller is given a boost according to a sensed or estimated temperature of the pressure roller. At other times during both idle and run, the temperature of the fusing roller is controlled by a sensor associated with the fusing roller.

Abstract: An image forming apparatus includes a source of at least one intermediate sheet which is preferably both thermally and electrically conductive. Toner images are transferred from one or more image members to the intermediate sheet under conditions of raised temperature and preferably with the assistance of an electric field. The toner image on the intermediate sheet is then overlaid with a receiving sheet and a combination of heat and pressure transfers and fuses the toner image to the receiving sheet in a single step, preferably while the sheets move at full machine speed. The sheets may then be slowed down or stopped, but are maintained together until cool at which point they are separated and the intermediate sheet fed back to the source of intermediate sheets. The image forming apparatus is particularly useful in creating multicolor toner images with small toners.

Abstract: A roller pair assembly for a pair of registration rollers which accelerates a sheet along an image receiving path. A compression spring positioned between a clip and a retainer provides a force at each end of the rollers urging them together. The retainer includes a nest for receiving the compression spring and a bearing surface for engaging a bearing housing for one of the rollers. The clip includes a projection for engaging the compression spring and a pair of resilient arms with detents engaging detents in an outside surface of a housing for the other roller.

Abstract: An image forming apparatus includes an image member which moves through a path past a series of stations. The series of stations create both first and second toner images on the same frame of the image member which images can be of different color. When the apparatus is used to form single color images, a charging station used in creating the second toner image is turned to a standby condition. In the standby condition, a bias is maintained on the charging station to repel toner particles from the first toner image that might otherwise accumulate on the charging station.

Abstract: An electrostatic image on an image member already containing a loose dry first toner image is toned with a second toner, for example, a toner of a second and different color from the first toner image. The toning is accomplished by a developer having a high coercivity permanently magnetized carrier and toner which is moved through a development zone by a rapidly rotating core inside a sleeve on which the developer moves. Pole transitions caused by the rapidly moving core make the high coercivity permanently magnetized carrier move vigorously in a wave motion having alternating crests and troughs. Scavenging of the first toner image is prevented by separating the sleeve from the image member sufficiently that the crests of the developer do not touch the image member during the toning process. An alternating electrical field is applied between the sleeve and the image member to enhance development.

Abstract: A pressure roller fuser includes a member at the end of at least one of the rollers for extending the position for applying the loading force between the rollers away from the center of the roller to cause the roller to bend with respect to the other roller. The bending causes a spreading of the nip at the edges of the roller to reduce wrinkling of the sheets fed through the nip. The amount of bend can be varied by varying the position of the loading force with respect to the center of the rollers, thereby allowing adjustment of the flare of the nip according to ambient conditions or the life of the rollers.

Abstract: A development station for applying toner to an electrostatic image includes a rotatable magnetic core and a roughened sleeve on which developer moves to develop the image. The outside surface of the sleeve contains fine extrusion-formed serrations, which serrations provide a roughness for the outside surface contributing to movement of developer in response to rotation of the magnetic core.

Abstract: A process of forming a composite toner image, for example, a two color image, includes steps of charging and exposing an image member to create a first electrostatic image and developing the image to form a first toner image. The process is repeated to form two toner images on the same area or frame of an image member. To reduce the tendency of the first toner image to spread into the second electrostatic image and also to reduce scavenging of the first toner image by the second toning step, the image member is exposed, immediately after the formation of the first toner image, to uniform activating radiation to form charges of a polarity opposite the electrostatic image, which charges tend to hold the first toner image to the image member. The uniform exposure can be effected through a transparent support to the image member.

Abstract: A sheet inverter generally of the type having a chute for receiving a moving sheet fed in through an input nip and out through an output nip includes an edge engaging stop which is resilient or movable to push the sheet into the output nip. The chute is defined by a pair of paper guides that are curved at one end to bend the leading edge of the sheet into a crosstrack curve that improves its beam strength while the trailing edge is not curved in the crosstrack direction, allowing it to be easily fed into the output nip.

Abstract: A two component development system includes developer with charged toner particles and oppositely charged carrier particles having high coercivity and permanent magnetism. The developer is moved through a development zone on a shell and into contact with an image member carrying an electrostatic image by rapidly rotating a magnetic core within the shell. The core has alternating magnetic poles around its periphery. To prevent carryout of carrier on the image member, an AC bias is impressed across the development zone.

Abstract: Apparatus for applying toner to an electrostatic image includes a sump for holding developer, which developer preferably includes a component having high coercivity and permanent magnetism. An applicator for moving the developer through a development zone includes a rotatable magnetic core and a sleeve around the core, which sleeve includes roughened portions leading to and away from the development zone and a smooth portion directly facing the development zone. The sleeve may also have smooth portions on its lateral crosstrack edges.

Abstract: Two-color images are created in a single pass by forming an electrostatic image having three levels of electrostatic potential, low, intermediate and high. Toner of a first color is applied to the image in the presence of an electric field urging the toner toward one of the levels of potential. A second toner is applied to the electrostatic image having a second color, but of the same polarity as the first toner, in the presence of a second electric field urging the second toner both toward the areas that have been toned by the first toner and toward one of the other levels of potential. If the first toner is of a dark color and is used for text and the second color is the light color used for highlighting, a quality two-color image can be made in a single pass using toners of the same polarity.

Abstract: A migration imaging system using a laser-addressable thermoplastic imaging member 10. The imaging member 10 comprises a supporting section 15 and a thermoplastic imaging surface layer 14. A charged, uniform layer of marking particles 24 is deposited on the imaging surface layer 14. An imagewise-modulated laser beam 24 transforms selected volumes of the imaging surface layer 14 in an imagewise pattern to a permeable state. Charged marking particles 42 that overlay a transformed volume then migrate into the imaging surface layer 14, due to an electrostatic attraction to the imaging member 10, so as to be retained. Unaddressed marking particles 56 are cleaned away by particle removing device 20B comprised of a magnetic brush utilizing hard magnetic carrier particles. The imaging member 10, or solely the imaging surface layer 14, may be transferred and bonded to a receiver member such as a drum for use as an exposure mask in a xeroprinting process, or to a receiver sheet 64 to provide a hard copy reproduction.

Abstract: Drum-shaped image and transfer members are controlled by a set of sensors and flags which determine the position of the leading edge of a toner image as it approaches a transfer zone and the leading edge of a receiving sheet as it approaches the transfer zone. A logic and control controls the speed of the transfer drum as it approaches the transfer zone to assure a predetermined spacial relationship between the two leading edges. The leading edge of the receiving sheet is sensed on the transfer drum by sensing a difference in reflectivity between the sheet and a low reflectivity area which the sheet overlies.

Abstract: The level of charge on toner in a developer is sensed or otherwise determined in an image forming apparatus. In response to such determination, a charge control member is adjusted between positions in which it triboelectrically charges the toner more or less because of greater or lesser contact with the toner.

Abstract: To create an overcoat on a toner image, a clear heat softenable particulate material is applied to a fusing surface before the fusing surface contacts the toner image in a fusing nip. The particulate material softens in the fusing process and ends up as a clear overcoat for the toner image, protecting it from scratches, fingerprints, deglossing and/or softening from heat.

Abstract: Image forming apparatus includes a fuser which has a fusing sheet for contacting the image bearing surface of a receiving sheet. The fusing sheet is attached at one end to a fusing sheet drum and at the other end to a spring for urging the fusing sheet in a first direction. The fusing sheet drum is rotatable in a first direction to allow the spring to move the fusing sheet in the first direction, which moves both the fusing sheet and the receiving sheet through a pressure nip formed by the fusing sheet drum and a pressure roller. The fusing sheet drum is rotatable in the second direction opposite the first direction for rewinding the fusing sheet on the fusing sheet drum. During the rewinding motion of the fusing sheet, the receiving sheet is separated from the fusing sheet by forcing the fusing sheet around a sharp bend.

Abstract: A magnetic brush device for applying toner to an electrostatic image includes an applicator having a rotatable core. The sleeve for the core is made of an insulating material and preferably has a thin metallic coating on the outside of the sleeve defining the sleeve's outside surface.

Abstract: A toner container has three chambers for holding three different color toners. The container is receivable by a receiving structure having a pair of opposing slots for receiving flanges on the base of the toner container. The receiving mechanism is part of a development device which includes a movable carriage for moving a plurality of development units into alignment with a development position. A portion, for example, an applicator of each development unit is movable with respect to the rest of the unit into toning relation with an image member at the development position.