Abstract: A roller driving apparatus having a roller contacting and rotating a photo-receptor web in a printer is provided. The apparatus includes a support shaft coaxially fixed to the roller and having a coupling groove formed in an outer circumferential surface thereof in a radial direction, a rotation member inserted around the support shaft, a coupling member coupled to the rotation member to protrude and retreat with respect to an inner circumferential surface of the rotation member, and inserted in the groove of the support shaft when protruding from the inner circumferential surface of the rotation member; a spring elastically biasing the coupling member in a direction to protrude from the inner circumferential surface of the rotation member, a motor, and a power transfer unit transferring the power from the motor to the rotation member to rotate the rotation member.

Abstract: A toner image is fixed to a receiving sheet by positioning the image between the receiving sheet and a hard surface of a web or sheet. Pressure is applied between the surfaces to fix the toner image to the receiving sheet with the toner image above its glass transition temperature. While the surfaces are still in contact, a heat sink member is brought into contact with one of the sheets or web to remove heat from the toner image and reduce the temperature of the toner image below its glass transition temperature allowing the receiving sheet to be separated from the hard surface without offset.

Abstract: A toner image carried by a heat softenable layer of a receiving sheet is fixed by feeding it into a pressure nip between a pressure member and a ferrotyping belt. To preheat the heat softenable layer, it is urged against the belt by a pressure or squeegee roller which contacts the back of the receiving sheet and urges it into contact with the belt. The adhesive characteristics of the heat softenable layer when heated by the belt cause the receiving sheet to follow the belt from the squeegee roller into the pressure nip.

Abstract: A fixing device fixes a toner image to a receiving sheet, especially to a receiving sheet having a heat softenable thermoplastic layer. The device has an endless belt which moves from a pressure nip through a cooling path away from the nip and then returns to the pressure nip. A heat exchanging roller is positioned between the portions of the path of the belt to subtract heat from the belt as it moves away from the nip and return that heat to the belt as it again approaches the nip. The heat exchanging roller has a thin conductive layer on an insulating core which thermally matches with the belt to increase the thermal efficiency of the fixing device.

Abstract: A development apparatus for use in electrostatographic copiers and printers includes a housing and a self-closing mechanism for completely and efficiently unloading or purging spent developer material from such apparatus. The mechanism further includes an aperture for discharging developer material from the housing, a self-closing conduit member connected to the aperture, and vacuum source for selectively transporting and removing developer material from the conduit member.

Abstract: An electrophotographic reproduction apparatus and method are provided for reproducing an original document sheet that includes a continuous tone pictorial information area and a line-type information area. Rather than reproducing the entire document sheet with screening of both types of information, means are provided for selectively screening only the pictorial information area on the reproduction. The means of one preferred embodiment comprises a programmable illumination source that is programmed through inputs by the operator using a digitizing tablet to selectively image portions of a screen onto a charged photoconductive web prior to development of the electrostatic image formed on the web so that only the area on the web receiving the pictorial image is exposed to the screen.

Abstract: An electrographic development station is disclosed which includes three magnetic brushes which sequentially apply toner to an electrostatic image on a moving photoconductor. The two upstream brushes rotate counter-current with respect to the movement of the photoconductor and have magnetic fields which overlap so that developer is carried from one brush to the other. The third magnetic brush rotates co-current with regard to such photoconductor movement. The two counter-current brushes apply a large quantity of toner to an electrostatic image on the photoconductor and the co-current brush applies a sufficient amount of toner to develop any incompletely developed portions of an electrostatic image.

Abstract: Web-tracking method and apparatus periodically reduces tension on endless web, laterally adjusts the position of the web, and then restores web tension.

Abstract: Apparatus and method for adjusting in situ the conductivity of the developer bristles of a magnetic brush development station in a copier to optimize toner development of electrostatic images.

Abstract: In an electrographic development apparatus having a magnetic brush and a sump wherein an auger transports developer from the sump to the brush, the auger being disposed in a tube located next to an inclined surface extending between the tube and the magnetic brush. The tube is provided with a plurality of openings. As the auger rotates it transports developer from the sump through the tube out of its opening to the inclined surface where it is distributed to the magnetic brush.