Abstract: A commutating connector which electrically connects conductive paths of a rotating electroded donor roll to a voltage source. The connector includes a housing made of an electrically insulating material. The housing defines a chamber to receive the donor roll. An electrically conductive brush is disposed in the chamber. The brush is mounted in pressing engagement against the conductive paths on the electroded donor roll to electrically connect the voltage source to the conductive paths on the electroded donor roll. The chamber is divided by a partition into a commutating and a non-commutating area. The housing has ports for receiving air to prevent particulate matter from accumulating between the brush and donor roll.

Abstract: A sensing and a control system are disclosed for eliminating registration error during duplex printing in a multi-pass xerographic printing system. The system registers a common physical edge of a sheet using multiple pairs of sensors. During the first pass or simplex pass, a first set of sensors detect the leading edge of a sheet of paper, and during the second pass or duplex pass, a second set of sensors detect the trailing edge of a sheet of paper. The control system regulates the rate at which a sheet should be driven to be in timed registration with a developed image on a photoreceptor at a transfer station. Variations in sheet size due to sheet cut tolerances are eliminated by the sensing and the control system since any offset is directed towards a common physical edge when developed front and back images on a photoreceptor are registered with a sheet of paper.

Abstract: A method for adjusting image quality in a printing machine having a variable density image developed on a photoconductive surface in accordance with an initial set of starting values. The method includes a first layer of detecting a plurality of densities of the variable density image and transmitting a plurality of signals with each signal being indicative of a density; generating new starting values, responsive to the plurality of signals, using a linearized perturbation model; calculating error values, responsive to the plurality of signals, minimizing the sum of the squares of the error values; testing the error values for convergence on a set of reference values with each reference value indicative of an acceptable density; repeating the detecting, transmitting, generating, calculating, and testing steps for a plurality of iterations.

Abstract: An epicyclic drive train arrangement having a plurality of output drive members which may be selectively driven from a single input drive member. A frame equipped with two pawls is operated by a single solenoid and spring combination. During successive cycles of solenoid operation, a selected pawl engages its mating gear by action of a solenoid plunger rod. The action prevents rotation of the selected gear while the pawl is engaged. The unselected pawl disengages its mating gear thereby allowing it to freely rotate. Multiple epicyclic drive train arrangements may be configured so as to drive a plurality of sheet feeding apparatuses in an electrophotographic printing machine.

Abstract: An apparatus for maintaining an ambient condition about a marking module. The apparatus includes a substantially air impervious enclosure defining a chamber having the marking module disposed therein. An air flow source supplies air to the chamber, and sensors respond to the amount of air flow to control the air flowing from the air source.

Abstract: An apparatus which detects a mass of marking material developed on a test patch recorded on a photoconductive surface. The apparatus includes a densitometer, a capacitor sensor and a controller. The densitometer is spaced from and adjacent to the photoconductive surface. The capacitor sensor is also positioned adjacent to the photoconductive surface and spaced therefrom. In operation, the densitometer generates a first signal proportional to the specular component of the total reflectivity of the material deposited on the test patch developed on the photoconductive surface. The capacitor sensor generates a second signal proportional to the mass of material developed on the test patch recorded on the surface. In response to these signals, the controller generates a first control signal as a function of the first signal received from the densitometer in response to the mass of material deposited on the test patch being less than a preselected mass.

Abstract: A printing machine of the type having a plurality of components for printing a document is disclosed. The printing machine includes an air source and a support member having a component mounted thereon. The support member is coupled to the air source which has output ports so that air flows from the output ports.

Abstract: An imaging member having a substrate with a photoconductive layer coated thereon is anisotropic. The anisotropic substrate is stiff along one axis and flexible along another axis. Reinforcing fibers are aligned in the substrate to achieve the relative stiffness.

Abstract: An apparatus for illuminating a photoconductive surface. The apparatus includes a housing defining a chamber and an open end. An imaging device is placed in the housing chamber. The imager transmits light rays through the open end of the housing to the photoconductive surface. An air pump is coupled to the housing. The air pump maintains an outwardly directed flow of air from the open end of the housing so as to move particles away from the open end. Electrically biased electrodes are located between the imaging device and the photoconductive surface. They attract the particles so as to prevent the particles from contaminating the imaging device.

Abstract: An apparatus in which a rotabably mounted donor roll advances toner to an electrostatic latent image recorded on a photoconductive surface. The donor roll has a plurality of conductive electrodes mounted thereon which rotate in unison therewith. A resistive disk is connected electrically to each of the conductive electrodes. The resistive disk also rotates in unison with the donor roll. An electrically conductive brush is in sliding contact with the resistive member. A voltage source, mounted stationarily, is coupled electrically to the resistive member. The voltage applied to each conductive electrode varies as a function of the distance between the voltage source and that conductive electrode.

Abstract: An apparatus for replenishing toner in a developer unit has a plurality of toner discharge units. A selected discharge unit is energized to dispense toner into the developer unit with the other discharge units being de-energized. After the energized discharge unit is substantially depleted of toner, another toner discharge unit is energized. The depleted toner discharge unit is removed and replaced with a new toner discharge unit.

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: An apparatus which advances sheets from different stacks of sheets. In one mode of operation, two stacks of sheets are supported side by side. A sheet feeder associated with each stack of sheets advances successive uppermost sheets from the respective stack to a transfer station of a printing machine. Alternatively, a single sheet feeder mounted movably in the sheet feeding apparatus may be employed to advance successive sheets from each of the stack of sheets, in lieu two sheet feeders. In the absence of these stacks of sheets, another oversized stack of sheets may be positioned in the sheet feeder. This oversized stack of sheets extends from a first sheet storing section into a second sheet storing section. When two stacks of sheets are disposed in the sheet feeder, one stack is positioned in the first sheet storing section and the other stack is positioned in the second sheet storing section. In this way, the sheet feeding apparatus has capability of feeding multiple size sheets.

Abstract: An apparatus for registering a sheet with a developed image on a moving surface. The apparatus includes a transfer station, detector, memory, and a registration transport. The detector is located at the transfer station and generates a registration signal in response to a sheet edge and a registration portion of the developed image. The memory stores sheet position factors and responds to the detector to update the factors. The registration transport communicates with the detector and the memory to move the sheet to the transfer station in registration with the developed image.

Abstract: A method and apparatus for identifying surface relief features of a substrate processed in a printing machine, and adjusting the machine parameters as a function thereof, before the substrate is processed through the machine. The apparatus includes a light source positioned adjacent to the substrate surface. A light sensing device, in a light receiving relationship with the substrate surface, detects light reflected from the substrate surface. A signal is generated indicative of sensed light intensity with a first magnitude range indicating ridges and a second magnitude range indicating depressions. Control circuitry, electrically connected to the light sensing device, receives the signals of ridges and depressions, and discriminates between them to generate a set of signals indicating surface relief features of the substrate.

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 in which sheet basis weight is determined as a function of a change in angular velocity of a roller defining a nip through which the sheet passes. The sheet basis weight is calculated in response to the change in angular velocity of the roll before and after the sheet enters the nip. In an electrophotographic printing machine, the change in angular velocity of the fuser roll or pressure roll may be used to calculate the sheet basis weight.

Abstract: An electrophotographic printing machine of the type in which a leading edge and a trailing edge of a moving sheet are detected. The improvement includes an elongated light source that is of a length greater than that of an irregularity on the moving sheet. The elongated light source extends in a direction substantially parallel to the direction of the moving sheet. A plurality of sensors are arranged in an array and are movably mounted on a support which is extended in a direction substantially parallel to the elongated light source. The elongated light source is movably mounted to another support, so as to position the light source relative to the array of sensors. A lens, interposed between the light source and the sensor array focuses light rays emitted from the light source on to the sensors. The sensors are in a receiving relationship with the light source. The elongated light source and the array of sensors define a passageway through which the moving sheet passes.

Abstract: A multicolor electrophotographic printing machine employing a plurality of developer units. Each of the developer units is actuated to develop a selected latent image with the appropriately colored toner particles. The other developer units are de-energized. In the development mode, the electrode wires and the donor roll are electrically biased to suitable voltages. In the non-development mode, the electrode wires have only a DC voltage applied thereon with the AC voltage being turned off. Substantially, simultaneously therewith, the electrical bias on the donor roll is adjusted to prevent further development. In this way, the developer unit does not develop a latent image in the non-operable mode and does not attract toner particles thereto from the latent image.

Abstract: An apparatus in which an advancing copy sheet is disclosed. The apparatus includes a moving imaging member having a toner image thereon. The copy sheet contacts an imaging member to transfer a toner image from the imaging member to the copy sheet. A fusing member fuses the toner image to the copy sheet and advances the copy sheet at an adjustable velocity while the copy sheet receives the toner image from the imaging member. A controller communicates with the imaging member and the fusing member to maintain the velocity of the copy sheet with that of the imaging member. The velocity is maintained at a selected relationship. An imaging member drive moves the imaging member at a first velocity. The imaging member drive includes: a crystal clock that generates a fixed reference signal, a programmable divider which receives the signal and generates a control signal, and a servo motor responsive to the control signal. A fuser drive rotates the fuser roll to advance the sheet at a second velocity.