Abstract: An electrophotographic printing machine in which an electrostatic latent image recorded on a photoconductive member is developed with a liquid developer material. The liquid developer material is advanced by a substantially smooth donor roll from a supply to the latent image at a development zone. The liquid developer material on the donor roll is maintained at a thickness ranging from about 3 microns to about 10 microns.

Abstract: An apparatus for advancing a sheet from a moving imaging member having an unfused image after transfer of the image to the sheet. After the image is transferred to the sheet, the sheet is advanced by a transport to a fuser. The transport has low impedance, high air flow to draw the sheet toward the transport for acquisition. As the sheet is moved across the transport, an increased air flow impedance causes a low vacuum pressure in the transport to provide a low drive force that minimizes quality and motion disturbances on the sheet. The low drive force exerted on the sleet is lower than a holding force of the sheet to the moving imaging member thus causing the sheet to slide on the transport.

Abstract: An apparatus which separates and advances successive individual sheets from a stack of sheets. The stack of sheets is supported on a tray which moves in upwardly direction to position the uppermost sheet in engagement with an endless belt. The endless belt moves in a recirculating path to advance successive sheets from the stack. A retard roller engages the endless belt to define a nip for separating any overlapped sheets. Interposed between the retard roller and the tray is a stationary guide member. As the sheet advances toward the nip from the stack, it engages the guide member and is guided toward the nip. A thin, flexible member has one end secured to the guide member. The other end of the flexible member is free and extends into the nip. The flexible member is interposed between the belt and the retard roller with the sheet passing between the belt and the flexible member into the nip.

Abstract: An apparatus for advancing a copy sheet includes a moving imaging member having an unfused toner image. The copy sheet is in contact with the moving imaging member to transfer the toner image from the imaging member to the copy sheet. The copy sheet is then engaged by a moving sheet transport. A vacuum draws the copy sheet toward the sheet transport while a pressure sensor detects the vacuum pressure in the transport to control the air flow through the transport so as to maintain a low and constant drive force in response to the level of vacuum sensed by the sensor. The low drive force exerted on the sheet is lower than a holding force of the sheet to the moving imaging member thus causing the sheet to slide on the transport.

Abstract: An apparatus in which a donor roll advances toner to an electrostatic latent image recorded on a photoconductive member. A plurality of electrode wires are positioned in the space between the donor roll and the photoconductive member. The electrode wires extend in a transverse direction relative to the longitudinal axis of the donor roll. The electrode wires are electrically biased to detach the toner from the donor roll so as to form a toner cloud in the space between the electrode wires and photoconductive members. Detached toner from the toner cloud develops the latent image. Electrode wires contact a portion of the surface of the donor roll. As the donor roll rotates, friction between the electrode wires and donor roll causes trapped debris to move away from the toner powder cloud region so as to minimize contamination produced streaks on the developed image.

Abstract: A printing machine in which a recording medium has a latent image recorded thereon. A housing stores a supply of liquid developer material therein. The housing is operatively associated with a donor member for substantially uniformly coating liquid developer material thereon. The donor member is spaced from the recording medium. As the donor member moves, it transports the developer material to a development zone wherein the latent image recorded on the recording medium attracts at least the toner thereto to form a developed image thereon. A multicolor image may be formed by repeating this process for different developer materials.

Abstract: An apparatus in which toner fines are recovered from a recirculating liquid transporting toner pellets cut from extruded toner. The recirculating liquid cleans the pellet cutter and forms a mixture of liquid and toner fines. The recovery unit is positioned between the pellet cutter and a station discharging the pellets. In this way, clean liquid flows into the pellet cutter during each cycle. The recovery unit has a housing defining a chamber having two sections. A sloping screen is located in the chamber covering one of the chamber sections. The mixture of toner fines and liquid is dispensed onto the screen. The liquid passes through the screen and is recirculated. Toner fines collect on the screen. A backwash system washes the toner fines from the screen into the other section of the chamber. The mixture of toner fines and liquid is pumped from the other chamber section into a separator. The toner fines are separated from the liquid and re-used in the extruder.

Abstract: An apparatus in which an electrostatic latent image recorded on a photoconductive member is developed with toner. A donor roll, spaced from the photoconductive member, transports toner to a development zone adjacent the photoconductive member. An electrode member is positioned in the development zone between the photoconductive member and the donor roll. The electrode member is electrically biased to detach toner from the donor roll so as to form a toner powder cloud in the space between the electrode member and the photoconductive member. A unitary magnetic roll is located in the housing to transport developer material to a reload zone where toner particles are attracted from magnetic carrier granules to the donor roll. The parameters are selected to optimize reload and suppress strobe lines.

Abstract: An apparatus in which an electrostatic latent image is developed with liquid toner. The apparatus has a liquid extruder that extrudes a thin film of liquid toner which is attracted to the electrostatic latent image forming a liquid image on a photoconductive surface. The extruder is electrically biased to a suitable magnitude and polarity to ensure that the liquid toner is attracted to the latent image. A vacuum is applied on the liquid toner as it is being attracted to the latent image so as to reduce the thickness of the layer coated thereon.

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. The donor roll transports a metered layer of developer material into contact with the latent image to develop the latent image. A conductive brush includes bristles having a diameter from about 6 to about 20 microns and contacts the metered layer of developer material on the developer roll. This substantially prevents the variation of triboelectric charge on the developer material on the donor roll so as to create a uniform charge level on the development material layer for development of the latent image.

Abstract: A single pass tandem architecture electrophotographic printing machine in which a photoconductive belt is supported by a plurality of spaced, stationary and arcuate members for transferring each color image from the photoconductive belt in registration with one another and having minimum registration errors from mechanical apparatus. Each of the latent images recorded on the photoreceptor belt is developed with different color developer material. The different color developed images are transferred from the photoconductive belt to a sheet of support material in superimposed registration with one another to print the desired multicolor information thereon.

Abstract: An apparatus which advances and separates sheets from a stack of sheets. The apparatus includes an operator pivotable frame having a nudger roll and a feed roll mounted thereon. In operation, the feed roll engages a retard roll. The retard roll is coupled through a gear to a slip clutch. In the event a single sheet is advanced by the nudger roll to the nip defined by the feed roll and retard roll, the frictional force between the sheet and retard roll is sufficient to overcome the torque applied on the retard roll by the slip clutch and the retard roll rotates in one direction permitting the sheet to pass through the nip. Alternatively, in the event multiple sheets are being advanced by the nudger roll into the nip, the frictional force is reduced and the retard roll rotates in the opposite direction under the torque applied thereon by the slip clutch driving the sheets back toward the stack from which they originally advanced.

Abstract: An apparatus in which an electrostatic latent image recorded on a photoconductive member is developed with toner. A donor roll, spaced from the photoconductive member, transports toner to a development zone adjacent the photoconductive member. An electrode member is positioned in the development zone between the photoconductive member and the donor roll. A magnetic roll transports carrier granules and toner particles to a loading zone adjacent the donor roll. In the loading zone, toner particles are attracted from the magnetic roll to the donor roll. A sealing member has a magnetic field induced therein by the magnet in the magnetic roll. The sealing member attracts carrier granules thereto preventing the carrier granules for being transported to the donor roll.

Abstract: An electrophotographic printing machine in which a moving photoconductive belt is supported in the region of the processing stations thereof. The photoconductive belt is guided in an endless path of movement. The region of the photoconductive belt opposed from at least one of the processing stations is maintained substantially planar with photoconductive belt flutter being substantially dampened.

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 module adapted to be mounted removably in a printing machine. The module has a photoconductive belt entrained about a plurality of rollers mounted on a frame. One of the rollers is movable between a non-operative position, in which the space between the rollers is reduced, and an operative position, in which the space between the rollers is increased. A charging station and a cleaning station are mounted on the frame of the module adjacent the photoconductive belt. When one of the rollers is in the non-operative position, a cover covers at least the photoconductive belt. The cover has an insert about which a portion of the photoconductive is wrapped. The insert supports the photoconductive belt in a non-tensioned condition external to the printing machine.

Abstract: An apparatus for transferring a developed image from a surface to a heated intermediate member. The intermediate member is reheated to at least partially melt the image therein. Thereafter, the image is transferred from the intermediate member to a sheet and fixed thereto.

Abstract: An apparatus which damps movement of sets of sheets being stacked on a support member. The support member moves, at selected intervals, to offset adjacent sets of sheets from one another. A pair of pivotably mounted arms have their free ends engaging the outermost sheet of the sets of sheets stacked on the support member. The arms apply a normal force on the sets of sheets without applying a lateral force thereon. In this way, the sets of sheets are damped without disturbing the integrity of the sets of sheets during offsetting.

Abstract: An improved method and apparatus for predicting the end of life of a photoreceptor, first records sampled data, then processes the data in order to interpolate the photoreceptor's end of life. Increased prediction accuracy is realized since both global photoreceptor information concerning a population of photoreceptors as well as information directed to a specific photoreceptor operating under particular environmental conditions are taken into account. This information is used not only to predict photoreceptor end of life but to make adjustments in the printing machine to correct xerographic degradations. In one embodiment, the information is used to direct an embedded end of life predictions system for notifying service at a remote site of photoreceptor problems in the printing machine in such a manner that it is transparent to a user of the printing machine.

Abstract: A toner cartridge in which a container defines an open ended chamber. The container is adapted to store a supply of toner in the chamber thereof. The open end of the chamber is sealed. A passageway is formed through the toner in the chamber. As the seal is peeled from the open end of the chamber, toner is discharged therefrom. As toner is discharged from the chamber, air displaced from the hopper receiving the toner moves from the hopper through the passageway onto the upper surface of the toner. In this way, displaced air does not impede the flow of toner particles and maintains a substantially uniform pressure on the discharging toner particles.