Abstract: An aluminum roll for use in an apparatus in which making particles are advanced toward a latent image to form a developed image. The roll is formed by diamond turning prior to forming an anodization layer and prior to applying a sealant.

Abstract: A noncontact seal for a donor roll in an electrophotographic printing machine. The seal is fixed in the developer housing and envelopes each end of the donor roll but does not contact the donor roll. The small space does not allow a positive airflow sufficient to cause toner particles to be emited from the developer housing so as to contaminate the other portions of the printing machine. The seal is made of a low friction material such as DELRIN.RTM. so that toner particles do not stick to the seal and cause a buildup that would be detrimental to the photoreceptive member.

Abstract: An electrophotographic printing machine of the type in which an electrostatic latent image recorded on a charge retentive surface is developed with toner particles to form a visible image thereof, including; a housing having a supply of toner and developer therein; a donor member for transporting toner from said housing to the development zone; means for conveying toner to the donor member; means for generating a negative air stream for carrying toner therein; and a filter for removing the toner from the negative air stream, said filter including filter material and oscillation means, operational connected to said conveying means, for oscillating said filter material to dislodge toner material collected in said filter when said generating means is disabled.

Abstract: An apparatus for filtering contaminants from marking particles is provided. The apparatus includes a conduit and a mover for moving the marking particles within the conduit. The apparatus also includes a screen positioned adjacent the conduit so that substantially all the marking particles discharged from the conduit pass through the screen.

Abstract: An apparatus and method for removing particles from a cleaner brush used to clean a photoreceptive surface. The apparatus and method include a cleaning brush or other cleaning device and a ceramic coated detoning roll resistive to wear. The detoning roll consists of a low electrically conductive coating over a conductive substrate material having a short electrical relaxation time constant.

Abstract: A channel for recirculating a stream of air located adjacent a stream of marking particles exiting substantially tangentially from a marking particle transport member within a developer unit is provided. The stream of marking particles defines an inner boundary thereof extending tangentially from a first position adjacent to the transport member and defines an outer boundary thereof spaced from the transport member and the inner boundary. The channel includes a first member positioned outside the stream of marking particles. At least a portion of the first member is positioned substantially adjacent the outer boundary of the stream of marking particles and is spaced from the transport member. The channel also includes a second member connected to the first member and a third member connected to the second member. The second member is positioned adjacent the transport member and is spaced from the stream of marking particles.

Abstract: A novel wire module support structure for controlling the spacing and edge wire angle of an electrode wire relative to a donor roll in a scavengeless development process is disclosed. A stationary wire support is arc shaped with a rounded edge and is located in close proximity to the donor roll end. This spatial relationship between the donor roll end and the wire support surface optimizes the donor roll surface to wire relationship. The wire support surface may be at a greater or lesser radius than the the donor roll surface. When the wire support surface is located at a larger radius than the donor roll surface, a clamp assembly is used to control the height of the wires with respect to the donor roll surface.

Abstract: An apparatus for developing a latent image recorded in a surface of a flexible photoconductive member. The apparatus includes a developer unit having a developer roll and a backing member. The roll is positioned opposed from the surface of the flexible photoconductive member and is used for developing the latent image with developer material. The backing member has an arcuate surface in engagement with a surface of the flexible photoconductive member opposed from the surface having the latent image recorded thereon. The flexible photoconductive member is wrapped about at least a portion of the arcuate surface of the backing member to form a negative wrap angle opposed from the developer unit. The centerpoint of the developer roll, the centerpoint of the backing member and the centerpoint of the arcuate surface are colinear.

Abstract: A heating device, which can be used in the fixing unit of an image forming apparatus, such as an electrophotographic copying or printing machine, for fixing a toner image on a final substrate. The heating device which is in the form of a heated fuser roller is provided with bands or coatings of material which impede the transfer of heat from the fuser roller to bearing structure associated therewith. The bands or coatings are applied by plasma spraying a ceramic material on either the surface of a fuser roll core or on journals of end caps, depending upon the specific construction of the fuser roller.

Abstract: A developer unit adapted to develop with marking particles a latent image. The developer unit includes a housing and a mover for moving the marking particles in a recirculating path within the housing. The developer unit further includes a fibrous element located adjacent the recirculating path to trap contaminants recirculated by the mover with the marking particles.

Abstract: An apparatus for supporting wires in a wire module for use in a scavengeless development system using wire maintaining members that longitudinally support the wires. The tops of the wire maintaining members have grooves that positively position the wires and set a desired wire to wire spacing. The wire maintaining members are integral with the wire module and are part of a wire tensioning system. The wire maintaining members are part of an assembly that allow the wires to be pretensioned to the operable development tension prior to the wire module being mounted to the developer housing. The wire maintaining members also have a unique mounting system which allows the wire module to be rotatably mounted to the developer housing.

Abstract: A method and apparatus involving the stopping and starting of the development of images, using hybrid development, to insure proper charging of the donor toner layer. A second (e.g. magnetic brush) roll is used to place toner on the donor roll or remove toner from the donor roll depending upon whether the development of images is stopped or started.

Abstract: A developer unit adapted to develop a latent image with toner particles. The unit includes a housing defining a chamber for storing a supply of toner particles in the chamber. The unit also includes a donor roll including an electrically non-conductive circumferential surface having a conductivity less than 10.sup.-8 (ohm-cm).sup.-1 and having a central region and opposed marginal regions disposed on either side of the central region with the diameter of the central region being less than the diameter of the opposed marginal regions. The donor roll is spaced from the latent image to form a development zone. The unit further includes an electrode member which is positioned in the development zone adjacent opposed marginal regions and spaced from the central regions of the donor roll. The electrode member is electrically biased to detach toner particles from the donor roll to form a toner powder cloud in the development zone with toner particles from the toner cloud developing the latent image.

Abstract: A corona generating device of the type in which a control grid adjacent a corona generating electrode regulates the charge deposited onto an imaging surface. The control grid defines elongated apertures located in alignment with the electrode, extending along a portion thereof wherein the control grid is adapted to selectively control the charge deposited on the imaging surface area for preventing development of the edge regions thereof.

Abstract: A method and apparatus involving the stopping and starting of the development of images, using hybrid development, to insure proper charging of the donor toner layer. A second (e.g. magnetic brush) roll is used to place toner on the donor roll or remove toner from the donor roll depending upon whether the development of images is stopped or started.

Abstract: A donor roll for the conveyance of toner in a development system for an electrophotographic printer includes an outer surface of ceramic. The ceramic has a suitable conductivity to facilitate a discharge time constant thereon of less than 600 microseconds. The donor roll is used in conjunction with an electrode structure as used in scavengeless development.

Abstract: In a development system for conveying toner to a latent image on a surface in an electrophotographic printing apparatus, including a donor structure spaced from the charge retentive surface for conveying toner to a development zone adjacent the surface and an electrode structure disposed between the donor structure and the surface, contaminants are removed from the development zone by a flow of air away from the development zone.

Abstract: A donor roll for the conveyance of toner in a development system for an electrophotographic printer includes an outer surface of phenolic resin. The resin is doped to a suitable conductivity to facilitate a discharge time constant thereon of less than 300 microseconds. The donor roll is used in conjunction with an electrode structure as used in scavengeless development.

Abstract: In a multi-color imaging apparatus, the voltage differential between developed and undeveloped areas of a charge retentive surface is reduced for precluding edge effect development. The developed areas correspond to charged areas on the photoreceptor while the undeveloped areas represent discharged or background areas on the photoreceptor. Development of the charged areas is followed by an erase step for reducing the voltage differential between the developed areas and the non-developed background areas prior to the next development step.

Abstract: A donor roll for the conveyance of toner in a development system for an electrophotographic printer includes an outer surface of phenolic resin. The resin is doped to a suitable conductivity to facilitate a discharge time constant thereon of less than 300 microseconds. The donor roll is used in conjunction with an electrode structure as used in scavengeless development.