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 tandem tri-level architecture. Three tri-level engines are arranged in a tandem configuration. Each engine uses one of the three primary colors plus one other color. Spot by spot, two color tri-level images can be created by each of the engines. The spot by spot images are transferred to an intermediate belt member, either in a spot on spot manner for forming full color images or in a spot next to spot manner to form highlight or logo color images. The images created by the tri-level engines can also be transferred to the intermediate in a manner such that both spot next to spot and spot on spot transfer is effected.

Abstract: An electrophotographic apparatus in which toner particles are moved from the toner hopper or dispenser cartridge to the developer housing and onto the donor roller in a single component development system for use in color reprographic systems. A rotating holey tube toner agitator is modified to incorporate structure or grooves on the outer peripheral surface. Further, by placing a shrouded toner dispense auger inside the holey tube, the development system architecture stays compact and improved toner powder pushing through the pre-load of toner on the donor roller results, thereby insuring delivery of fresh toner evenly across the length of the developer housing. With more efficient pre-load, agitator rotational speed and bias can be reduced, leading to less toner effluents emanating from the developer housing without adversely affecting the cycle to cycle donor roller toner reload.

Abstract: In the development system of an electrophotographic apparatus, a selected ratio of electrostatic charge per unit mass for particles adhering to a member transporting to a surface having a latent image recorded thereon is maintained. Means are provided for controlling a ratio of particle mass to the member surface area, and such means are controlled as a function of the selected ratio of electrostatic charge to unit mass to regulate the ratio of particle mass to the member surface area so as to substantially maintain particle electrostatic charge to unit mass ratio at the selected ratio of electrostatic charge to unit mass.

Abstract: An apparatus which develops a latent image recorded on an image receiving member with developer material. A donor roll is positioned in a chamber of a housing having a supply of developer material therein. The donor roll transports a metered layer of developer material into contact with the latent image to develop the latent image. A rotating and translating brush gently disturbs the metered layer of developer material on the donor roll. This substantially prevent the accumulation of developer material agglomerates on the donor roll so as to create a more stable, uniform developer material layer for development of the latent image therewith.

Abstract: A printing machine having a pair of photoconductive drums with a transfer roller interposed therebetween produces a full color document in two operating cycles. During the first operating cycle, a first color developed image is transferred from the first photoconductive drum to a sheet moving with the transfer roller. A second color developed image is transferred from the second photoconductive drum to the sheet in superimposed registration with the first developed image transferred thereto. During the second operating cycle, the foregoing process is repeated for a third color developed image and a fourth color developed image. In this way, a full color composite toner image is formed on the sheet.

Abstract: An apparatus which develops an electrostatic latent image recorded on a photoconductive member with toner. The toner in the chamber of the developer housing is fluidized and transported thereacross by an elongated member. A donor roller advances the toner particles to a latent image recorded on a photoconductive member. A rotating rod resiliently urged into contact with the donor roller charges the toner on the donor roller. In order to attract toner particles to the donor roller, the elongated member and the charging rod are electrically biased by voltages having the same polarity. The elongated member and the charging rod are electrically biased by voltages of opposite polarity to denude the donor roller of toner particles.

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: Developer apparatus and toner dispenser system therefor that is capable of modulating toner addition very uniformly, not only across the width of a developer housing but selectively along a length of a developer member in an area that was previously depleted by its passage through a development nip. Thus, toner is dispensed only where it is needed.

Abstract: Disclosed is an improved toner composition comprised of resin particles, pigment particles, and present on the surface thereof additives comprised of a charge enhancing component sorbed on a flow aid composition.

Abstract: A method of obtaining continuous tone reproductions in a raster scanned digital image having a given number of pixels for each halftone cell of the digital image and using four modulating levels for each pixel of the output scanner including a black and a white pixel level, the method comprising the steps of: choosing two reflectance gray levels intermediate the black and white levels to combine with the black and white pixel levels for providing quadruples, four numbers specifying the number of each kind of pixel in the halftone cell, for modulating the output scanner, determining a total number of average halftone cell gray levels to be available for the digital image, creating a list of quadruples that describe all possible average halftone cell grey levels available with the four modulating levels, and selecting a set of quadruplets from said list equal to a desired number of gray levels, said set of quadruplets selected to maximize the occurrence of black and white pixel levels in each halftone cell.

Abstract: A process for the preparation of stable developer compositions, which comprises treating coated carrier particles with metal salts, or metal salts of fatty acids, and thereafter admixing these particles with a colored toner composition containing metal salts or metal salts of fatty acids, and comprised of resin particles and colored pigment particles, and wherein the salts are present in an amount of from about 0.01 to about 1 percent by weight.

Abstract: A carrier composition with a conductivity of from about 10.sup.4 to about 10.sup.10 (ohm-cm).sup.-1, and comprised of a mixture of a first carrier component and a second carrier component, at least one of said carrier components containing a polymeric coating thereover, and wherein at least one coating contains conductive particles.

Abstract: Disclosed is an improved stable colored toner composition comprised of resin particles, colloidal silica additive particles, and colored pigment particles; and wherein each of the toners are encapsulated in a continuous shell from about 1 to about 30 percent by weight of a waxy substance with a molecular weight of from about 500 to about 20,000.

Abstract: A negatively charged developer composition comprised of a toner composition with an average particle diameter of from about 4 to about 9 microns containing a mixture of styrene butadiene copolymers, and styrene methacrylate copolymers; pigment particles selected from the group consisting of cyan, magenta, yellow, red, blue, green, brown, and mixtures thereof; first external additive particles of colloidal silica; second external additive particles of fatty acid metal salts; and carrier particles comprised of a ferrite core with a polymeric coating thereover, which coating has dispersed therein conductive particles.

Abstract: A process for generating consistent high quality colored images for extended periods consisting essentially of (1) providing a xerographic imaging or printing apparatus; (2) adding thereto a stable two-component developer composition comprised of first polymer particles, second polymer particles, and blended flow additive particles and carrier particles; (3) forming electrostatic latent images in the apparatus; and (4) developing the images formed wherein the developer composition retains its triboelectric properties of from about 20 to about 40 microcoulombs per gram for over 500,000 imaging cycles, subject to the provision that the second polymer particles are of a different composition than the first polymer particles.

Abstract: Disclosed is a process for generating consistent high quality images comprised of (1) providing a xerographic imaging or printing apparatus; (2) adding thereto a stable two component developer composition comprised of toner composition with an average particle diameter of from about 6 to about 10 microns with resin particles, first pigment particles, second magnetite pigment particles, which are present in a greater amount than the first pigment particles, and blended flow additive particles; and carrier particles consisting of a ferrite core, or a steel core, and a coating thereover selected from the group consisting of terpolymers of styrene, methacrylate, and triethoxysilane; and polymethacrylate, which coating has incorporated therein conductive particles; (3) forming electrostatic latent images or magnetic images in the apparatus; and (4) developing the images formed.

Abstract: Disclosed is a two-component developer composition enabling smudge resistant images which is comprised of improved two-component contamination free developer composition comprised of (1) magnetite; (2) a polyester resin comprised of the polymeric esterification product of a dicarboxylic acid and a diol comprising a diphenol of the following formula ##STR1## wherein R is selected from substituted and unsubstituted alkylene radicals of from about 2 to about 12 carbon atoms, alkylidene radicals of from 1 to 12 carbon atoms and cycloalkylidene radicals of from 3 to 12 carbon atoms; R' and R" are selected from substituted and unsubstituted alkylene radicals of from 2 to 12 carbon atoms, alkylene arylene radicals of from 8 to 12 carbon atoms and arylene radicals; X and X' are selected from hydrogen or any alkyl radical having from 1 to 4 carbon atoms; and each n is a number of from 0 (zero) to 4; and (3) carrier particles.

Abstract: An improved apparatus for causing the development of electrostatic latent images on an imaging member consisting essentially of providing a moving deflected flexible imaging member, a moving toner transporting means, a development zone situated between said members, with the distance between the flexible imaging member and the transporting member being from about 0.05 millimeters to about 1.5 millimeters, a first developer reservoir with magnetic developer particles, a second developer reservoir with colored developer particles, and a magnetic separator comprised of a stationary shell with rotating magnets therein.

Abstract: Disclosed is an improved, simple, economical process for generating documents, such as personal checks, suitable for magnetic image character recognition, which process comprises generating such documents with conventional xerographic methods in a high speed electronic laser printing device, and wherein there is selected as the developer composition a magnetic toner containing from about 20 percent by weight to about 70 percent by weight of magnetite particles, and from about 30 percent by weight to about 80 percent by weight of toner resin particles of styrene copolymers, such as a styrene butadiene copolymer, a styrene n-butylmethacrylate copolymer, or polyesters, and wherein the carrier particles are comprised of ferrite cores, coated with various polymeric resinous compositions.