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 color electrophotographic printing machine in which latent images having a resolution of at least 1.44 million pixels per square inch are recorded on a photoconductive member. Different color toner powder images are developed in superimposed registration with one another to form a composite multicolor image. The composite multicolor image is transferred from the photoconductive member to a receiving member. Toner particles which have a selected pigmentation and small volume average diameters are used to minimize curl of the receiving member.

Abstract: A solid area process control for scavengeless development using a transport roll-to-donor roll DC bias as a control parameter in an electrophotographic printing machine is disclosed. The process develops a latent image of a solid area toner patch on a photoconductive belt. Once the patch is developed, the patch is measured with an infrared reflectance type sensor. The measured development mass is compared to a target value stored in the machine memory. A test of the comparison is performed by the process. If the result of the test is less than the target value, the transport roll-to-donor roll bias is increased and the process ends. If the result is more than the target value, the transport roll-to-donor roll bias is decreased and the process ends, otherwise the process stops because the measured development is acceptable. The process is run at predetermined intervals to maintain constant output from the electrophotographic printing machine.

Abstract: An apparatus develops an electrostatic latent image on a charge-retentive surface. A donor roll is selectably rotatable in a process direction and in a reverse direction relative to the process direction. A toner mover loads toner particles onto a portion of the surface of the donor roll. A metering blade is disposed downstream of the toner mover in the process direction. A seal is disposed upstream of the toner mover in the process direction, and is adapted to remove at least approximately half of the undeveloped toner from the donor roll.

Abstract: A scavengeless/non-interactive development system using wire electrodes in a development nip between a donor member and a charge retentive surface. The wire electrodes are electrically biased for causing toner particles to form powder clouds in the development nip. Uniform powder clouds are ensured by effecting rubbing contact between the toner particles on a donor roll and a conductive surface.

Abstract: An apparatus develops an electrostatic latent image on a charge-retentive surface. A donor roll is selectably rotatable in a process direction and in a reverse direction relative to the process direction. A toner mover loads toner particles onto a portion of the surface of the donor roll. A metering blade is disposed downstream of the toner mover in the process direction. A seal is disposed upstream of the toner mover in the process direction, and is adapted to remove at least approximately half of the undeveloped toner from the donor roll.

Abstract: An apparatus in which contaminants are on-the-fly removed from an electrode wire positioned between a donor roller and a photoconductive surface. A magnetic roller is adapted to transport developer material to the donor roller. The electrode wire is electrostatically biased with respect to the donor roller to remove contaminants therefrom. The electrostatic wire bias polarity corresponds with the contaminant charge polarity to repel the contaminants from the wire.

Abstract: A process for extending the life of magnetic brush cleaners comprising carrier particles, a magnetic roll, and biased detone roll with a scraper by treating said carrier particles with a metal oxide.

Abstract: Disclosed is a process for forming two-color images which comprises (1) charging an imaging member in an imaging apparatus; (2) creating on the member a latent image comprising areas of high, intermediate, and low potential; (3) developing the low areas of potential with a colored developer comprising a colored first toner comprising a polymer resin selected from the group consisting of styrene-butadiene copolymers, styrene-acrylate copolymers, styrene-methacrylate copolymers, and mixtures thereof, a blue first colored pigment of the formula C.sub.32 H.sub.16 N.sub.

Abstract: An apparatus which develops a latent image recorded on an image receiving member with developer material. A chamber in the developer housing stores a supply of developer material. A donor roll is positioned in the chamber of the housing so as to transport developer material into contact with the latent image to develop the latent image. A rotating, elongated member fluidizes the developer material. As developer material is discharged from a storage container into the chamber of the developer housing, it exerts pressure on the fluidized developer material to move the developer material from one end of the housing to the other end thereof. An electrical bias is applied between the elongated member and the donor roll so that developer material is attracted to the donor roll as the developer material advances from one end of the developer housing to the other end thereof.

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: A process for extending the life of magnetic brush cleaners comprising carrier particles, a magnetic roll, and biased detone roll with a scraper by treating said carrier particles with a metal oxide.

Abstract: A process for avoiding, or minimizing toner contamination of electrodes in a scavengeless electrophotographic imaging apparatus which comprises adding to the donor roll present in said apparatus a toner comprised of resin, pigment, charge additive, and a metal oxide, or a mixture of metal oxides.

Abstract: Color image creation wherein the color is user selectable selection of a desired color establishes the duty cycle of each of a plurality of developer structures which, in turn, determines how much, if any, of each color toner is deposited on a particular image. The duty cycle of each developer structure may vary between zero and a predetermined maximum time which corresponds to the time it takes for an image area on a charge retentive surface to move through a development nip intermediate the charge retentive surface and one of the developer structures.

Abstract: An apparatus which develops an electrostatic latent image recorded on a photoconductive member with toner. Fluidized toner is transported from one end of the developer housing to the other end. An electrical bias is applied between the toner mover and the donor roller so as to attract toner to the donor roller. A rotating rod resiliently urged into contact with the donor roller charges and meters the toner on the donor roller. Electrically biased wires in the development zone between the photoconductive member and the donor roller detach toners from the donor roll so as to form a toner powder cloud in the development zone. Detached toner from the toner powder cloud develops the latent image.

Abstract: An apparatus which develops a latent image recorded on an image receiving member with marking particles. A chamber in a developer housing stores a supply of charged marking particles. The marking particles having a charge distribution. A donor roll is positioned in the chamber of the housing to transport marking particles closely adjacent to the latent image to develop the latent image. A rotating, elongated member moves the marking particles. An electrical bias is applied between the elongated member and the donor roll to selectively attract marking particles from the elongated member to the donor roll. The marking particles attracted to the donor roller have a charge distribution with a selected range. The range of the charge distribution of the marking particles attracted to the donor roller is less than the range of the charge distribution of the marking particles being moved by the elongated member.

Abstract: A single component development system utilizing insulative nonmagnetic toner. A toner mover transports toner from a supply of toner for transfer to a donor roll from which it is deposited on to latent electrostatic images contained on an imaging surface. An electrically biased flap of conductive material is supported for rubbing contact with the surface of the toner mover. Supporting the electrically biased, conductive flap in rubbing contact with the toner mover results in effective reloading of the doner roll notwithstanding the presence a high stress condition such as the requirement for developing images containing conditnuous solid areas.

Abstract: An apparatus for charging insulating toner particles comprised, in operative relationship, of a means for charging insulating toner particles and a means for transporting insulating toner particles, said means for charging and said means for transporting biased to a predetermined potential wherein the transporting means contains therein a coating selected from the group consisting of a chlorotrifluoroethylene vinyl chloride copolymer, styrene copolymers, and silicone resins with conductive particulate particles therein.

Abstract: There is disclosed an apparatus for effecting the charging of insulating toner particles in a charging zone situated between a moving roller, and a toner transporting roller or belt with a coating thereover comprised of a mixture of fluoropolymers and conductive particulate particles, such as carbon black. The coating may be textured with silica particles. Useful polymers selected for the coating include fluorinated ethylene propylenepolytetrafluoro ethylene copolymers.

Abstract: A printing machine having an operator removable housing comprising a photoconductive member with a web entrained about a portion thereof. A latent image is recorded on the photoconductive member and marking particles transported to the portion of the web entrained about the photoconductive member. In this way, the latent image recorded on the photoconductive member attracts the marking particles to the web in image configuration. A copy sheet is advanced into contact with the marking particles on the web. The marking particles interposed between the web and the copy sheet are heated. After cooling, the copy sheet is separated from the web with the marking particles remaining affixed thereto.