Abstract: A liquid composition for developing latent electrostatic images comprising toner particles associated with the pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

Abstract: A voltage waveform is applied to a development electrode in an electrophotographic apparatus to assist in the cleaning of the development electrode without degrading the photoconductor surface with excessive toner particles. The waveform establishes a bias voltage of one polarity on which are impressed pulses of the other polarity of sufficient amplitude and duration to dislodge charged toner particles from the surface of the development electrode, but insufficient to move the toner particles to the photoconductor surface.

Abstract: A thermal detector and method of making the same in which a suspension of binder-encapsulated copper particles is produced by comminuting a chip formed by dry-milling a major amount of copper particles with a minor amount of a binder and a charge director to produce the chip of copper particles in an encapsulant having functional sites. The bits of comminuted material are wet-milled with a major amount of a low-boiling aliphatic hydrocarbon to produce a suspension from which encapsulated copper particles are deposited on a substrate by electrophoresis. The deposit is electron-beam cured to form the detector.

Abstract: A process for replenishing a liquid developer, and a liquid developer made by the process, comprising transferring a first composition comprising a carrier liquid and a charge director into the liquid developer and transferring a second composition comprising toner particles, carrier liquid and charge director into the liquid developer. The amount of charge director in each of the first and second compositions charge director is in a predetermined ratio which results in a constant level of charge director in the liquid developer when the liquid developer is utilized in an electrostatic or printing process.

Abstract: Documents are advanced to a registered position along the trailing edge of the exposure platen of an electro-photographic copier by a flat belt supported adjacent to the registration edge by a pulley formed with axially spaced indentations to produce corresponding corrugations in the belt. A registration gate having a blocking position in which transversely spaced fingers extend into the belt corrugations arrests the documents at the registration edge while the normal-diameter portions of the belt pulley press the document downwardly to prevent it from riding over the registration gate. Position pulses from an encoding wheel are counted to determine the position of the document, and drive motor is slowed to one-fifth its normal speed when the document advances within a predetermined distance of the registration edge.

Abstract: Apparatus for cleaning the photoconductive drum of an electrostatic copier in which a rotating foam roller and a self-cleaning squeegee blade are sequentially arranged adjacent the photoconductive surface at a location following the station at which the image has been transferred to copy material such as paper. The self-cleaning squeegee blade is formed by a driven endless belt which extends across the entire photoconductive surface and which is so disposed that an edge portion or portions contact the surface of the photoconductor. The endless belt is cleaned by means remote from the photoconductive surface. In various embodiments of the invention the endless belt contacts the photoconductive surface at an acute, a right, and an obtuse angle to a tangent to the photoconductive surface. Means is provided for supplying developer liquid to the developer applicator on start-up of the machine and to the cleaning apparatus upon initiation of a copying operation.

Abstract: A paper control gate directs a sheet from any one to any other of a plurality of three or more stations angularly disposed about a single rotatable shaft mounting one or more vanes. The vanes are in general curved and deflect a sheet through an appreciable angle. Where there is little or no sheet deflection between stations, a pair of parallel vanes may provide a passageway. The vanes may be flared at each end to accommodate reversible sheet paths. Large shaft rotations are employed. The stations are equally spaced from the shaft and each is provided with a frictional sheet drive roller.

Abstract: A copier wherein charge director is supplied to a liquid developer in response to a conductivity measurement thereof. Toner concentrate deficient in charge director is supplied to the liquid developer in response to an optical transmissivity measurement thereof. Conductivity is measured by a pair of spaced electrodes immersed in the developer and through which a variable alternating current is passed. A variable capacitor neutralizes the inherent capacitance of the electrodes. A phase sensitive detector is provided with a reference voltage having the same phase shift as that caused by capacitive effects. The conductivity measurement is corrected in response to a developer temperature measurement.

Abstract: A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers of tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

Abstract: A sheet feeder transports sheets from a sheet supply, such as a document tray, to a distant location, such as a registration position on the platen of an electrophotographic copier. A sensing device monitors a time period which starts when a sheet advancing mechanism is actuated and ends when a sheet reaches the distant location. An indication of abnormal operation is provided if the sheet does not reach the distant location within a preset time period. The preset time period is initially set at one period of time and subsequently set at a shorter period of time. The initial time period is longer to allow the sheets to become fully engaged with the sheet feeder after initial loading, while the subsequent period is shorter to provide a quicker indication of abnormal operation.

Abstract: A photographic printer for producing a visible image of information received in the form of a plurality of discrete electrical signals in which the signals are applied respectively to a plurality of devices each of which acts as a source of light in response to an electrical signal and which devices are arranged in an array adjacent to a photosensitive surface to direct light thereon in response to said signals thus to produce an image of the information on the surface. It is preferred form the printer is an electrophotographic printer in which the photosensitive surface is a charged photoconductor so that light from the sources produces a latent electrostatic image which may be developed and transferred to plain paper, for example.

Abstract: The disclosure is directed to liquid electrophotographic copying equipment and more particularly to an apparatus to dispense a liquid charge director composition to a reservoir that contains a liquid developer composition. Generally, the apparatus comprises a charge director reservoir including a pressure cell arranged below the liquid level of the charge director reservoir. The pressure cell has a volume to contain a predetermined amount of liquid charge director composition. The pressure cell is provided with an opening to permit a flow of liquid charge director composition from the charge director reservoir and into the interior of the pressure cell and vice versa. A tubular conduit extends from the interior of the pressure cell to the reservoir that contains the liquid developer composition to provide fluid communication therebetween.

Abstract: A method and apparatus capable of forming an image in an electrostatic apparatus having a photoconductor with a latent electrostatic image thereon. An electrical potential having a polarity opposite to the photoconductor is applied to a push development electrode thereby coating the image areas, as well as the background areas, of the latent electrostatic image. The background areas are cleaned by applying a potential having the same polarity as the photoconductor to a second pull development electrode.

Abstract: A system for reducing hydrocarbon emissions from a high speed liquid reprography process. Hydrocarbon ladened vapors from the reprography process are directed through an activated charcoal bed. The bed is regenerated from time to time by a flow of controlled temperature regenerating air. Whereas the reprography process generates hydrocarbons at a highly fluctuating rate and mixed in large volumes of air, the carbon bed regeneration produces hydrocarbons at a controlled rate in a small volume of air. These hydrocarbons are removed by removal means which may be either a catalytic reactor or a condensation device.

Abstract: An electrophotographic liquid toner composition having lower saturation density and method of reducing the saturation density comprising a toner particle formed from a resin, a solid pigment, and a transparent filler, said pigment and said transparent filler having similar surface energies such that they impart similar triboelectric charging properties to said composition, and said composition is further characterized in that the triboelectric properties of said composition are substantially equivalent to the triboelectric properties of a reference composition in which said filler is not present and in which the combined amount of said pigment is equal to the amount of pigment in said reference composition, and in that said transparent filler lowers the saturation density of said composition so that the saturation density of said composition is lower than the saturation density of said reference composition.

Abstract: Documents are advanced to a registered position along the trailing edge of the exposure platen of an electrophotographic copier by a flat belt supported adjacent to the registration edge by a pulley formed with axially spaced indentations to produce corresponding corrugations in the belt. A registration gate having a blocking position in which transversely spaced fingers extend into the belt corrugations arrests the documents at the registration edge while the normal-diameter portions of the belt pulley press the document downwardly to prevent it from riding over the registration gate. Position pulses from an encoding wheel are counted to determine the position of the document, and drive motor is slowed to one-fifth its normal speed when the document advances within a predetermined distance of the registration edge.

Abstract: A magnetic recording medium having a coating of magnetic particles deposited thereon by electrophoresis. Magnetic particles are encapsulated by dry milling in a thermoplastic binder which is insoluble at ambient or room temperatures and is softenable at temperatures higher than 70.degree. C. A charge director for producing functional sites in the higher is incorporated in the encapsulating polymer during the dry-milling step. The encapsulated mass is comminuted or pulverized and then wet-milled with a major amount of a low-boiling aliphatic hydrocarbon liquid. A suspension is then formed with additional hydrocarbon liquid. Additional charge director may be added, either during the wet-milling step or during the suspension-forming step. The suspension is then used as a bath from which the coating is deposited by electrophoresis. The magnetic particles are oriented by the application of a magnetic field, either during the depositing step or subsequent thereto.

Abstract: A method of and apparatus for accurately positioning a generally rectangular sheet being fed in a direction generally parallel to one edge thereof in which a first stop offset from the centerline of the sheet in the direction of feeding engages the leading edge of the sheet to initiate a turning action thereof and in which second and third edge stops engage the lateral edges of the sheet with reference to the direction of feed and at points adjacent to the sheet corners before appreciable turning movement of the sheet has taken place.