Abstract: A system and method for registering a sheet transported along a sheet path of a printing system, including receiving a sheet at a first location, transporting the sheet along the sheet path from the first location in a downstream direction at a first speed. The speed at which the sheet is transported is decreased from the first speed to a second speed. The transported sheet is received at a second location downstream from the first location and registered at the second location, including correcting at least one of lateral position of the sheet, skew of the sheet, and timing error in a downstream direction.

Abstract: An electrostatographic and/or xerographic machine includes a media path adapted to move a media sheet. Sensors are positioned adjacent the media path. The media sheet has a leading edge and a trailing edge and the sensors are adapted to identify locations of the leading edge and the trailing edge of the media sheet. A marking device is positioned adjacent the media path. The marking device is adapted to print first items on a first side of the media sheet and print second items on a second side of the media sheet. A registration controller is operatively connected to the media path and to the sensors. The registration controller determines a length between the leading edge and the trailing edge of the media sheet using output from the sensors, and determines the parallelism between the leading edge and the trailing edge of the media sheet using output from the sensors.

Abstract: A method of calibrating once-around and harmonic errors of encoded nips is provided. An encoder with an index pulse is used to measure the velocity and rotation of the driven wheel or idler. The geometry of the drive train and wheel and idler is chosen so that their once around and harmonic frequencies are unique such that no other drive errors will generate these frequencies. The method includes running the idler or wheel at substantially constant velocity for N revolutions. Each index triggers the collection of velocity data, which is averaged for N revolutions. This process detects drive train motion errors that are periodic with respect to the timing of the index pulse (i.e., once per revolution of the wheel or idler). Once the velocity errors have been measured, corrections are made. This method may be incorporated in xerographic machines as part of a setup or calibration procedure.

Abstract: A sheet handling system comprising a sheet registration system having sheet registration nips and a receiving system for a sheet including a capturing point for engaging said sheet. Auxiliary nips are positioned between the sheet registration nips and the receiving station. The auxiliary nips are moveable between an open and closed position. A controller receives a signal indicative of the length of said sheet and sends a signal to the auxiliary nips to be in a sheet engaging position when the length of the sheet is less than the distance between the sheet feeding nips and the capturing point of said receiving station and be in an open position if the length of said sheet is greater than the distance between the sheet registration nips and the capturing point of said receiving station. In another embodiment, the auxiliary nips are maintained in their open position until the trailing edge of a sheet is about to leave the sheet registration nips, at which point the auxiliary nips are closed.

Abstract: A method of calibrating once-around and harmonic errors of encoded nips is provided. An encoder with an index pulse is used to measure the velocity and rotation of the driven wheel or idler. The geometry of the drive train and wheel and idler is chosen so that their once around and harmonic frequencies are unique such that no other drive errors will generate these frequencies. The method includes running the idler or wheel at substantially constant velocity for N revolutions. Each index triggers the collection of velocity data, which is averaged for N revolutions. This process detects drive train motion errors that are periodic with respect to the timing of the index pulse (i.e., once per revolution of the wheel or idler). Once the velocity errors have been measured, corrections are made. This method may be incorporated in xerographic machines as part of a setup or calibration procedure.

Abstract: A method of registering sheets laterally and in skew enables active sheet deskew without translating the sheet in the cross-process direction. A sensor carriage position is controlled to find the sheet edge after which deskew control can start. The average value of the carriage position can then be fed in a feedforward manner to move the image location to match the average paper position. This achieves good average lateral registration and active skew control at a reduced cost.

Abstract: A system and method are provided to calibrate a sheet velocity measurement derived from a drive nip system incorporating idler encoders. Testing has found that the velocity from an idler encoder system is subject to systematic errors, for example, errors that occur when the system is running media of different thicknesses. The system uses one or more nips with encoders mounted on the idlers and a number of point sensors that are spaced apart in the process direction. The point sensors are used to measure the transmit time of the sheet (lead edge or trail edge) between two sensor positions. The transit time is used to calculate the average sheet velocity. The average sheet velocity is compared with the velocity derived from the idler encoders to derive a correction factor. The velocity sensor are used to calibrate the idler-encoder velocity sensors, providing a worthwhile improvement to idler-encoder technology for media handling (e.g., feeding, transport, and finishing) in direct marking systems.

Abstract: A closed loop feedback method that continuously adjusts the lateral and skew position of a sheet includes a first sensor that is used to measure lateral sheet edge position. A second sensor measures the lateral sheet edge position at a certain distance from the first sensor. Sheet skew values can thus be calculated. Lateral and skew controllers provide outputs to lateral and skew actuators, respectively, to adjust the sheet position. A different method of registering sheets laterally and in skew enables active sheet deskew without translating the sheet in the cross-process direction. A sensor carriage position is controlled to find the sheet edge after which deskew control can start. The average value of the carriage position can then be fed in a feedforward manner to move the image location to match the average paper position. This achieves good average lateral registration and active skew control at a reduced cost.

Abstract: In a system of automatic deskewing and registration of print media sheets moving in a printer paper path with laterally spaced apart differentially driven rollers controlled by the sensing of the moving sheet lead edge skew at a position downstream in said paper path there is further provided a subsequent trail edge sheet skew detection of the same moving sheet at a position upstream of the differentially driven rollers to subsequently differently control the differential driving of those same rollers to make a final and normally much smaller deskewing correction in the same sheet after the majority but less than all of said sheet is downstream of the differentially driven drive rollers.

Abstract: Parallel printing systems and methods incorporate inverter assemblies for not only inverting media during transport through the system but also to register the media or provide a velocity buffer transports with different drive velocities. The inverter assemblies can include the capability to optionally deskew the media and provide lateral registration corrections. The inverter assembly nip rollers are sufficiently spaced from process drive nip rollers to decouple a document in the inverter assembly from the highway paths. The method comprises combining the inverting function selectively with either the registering or the velocity buffering functions.

Abstract: An image-to-sheet closed loop registration system tracking the image drum position and/or velocity and coordinating movement of the sheet into the transfer nip based on such information.

Abstract: A flexible media integration system (10) includes a multifunction flexible media interface system (12). The interface system includes a plurality of flexible media input areas (22, 24, 26) for receiving flexible media (14), such as sheets of paper, from a plurality of associated input processors (16, 18, 20), such as printers or paper feeders. A plurality of flexible media output areas (32, 34) provide outputs to different associated flexible media output processors (36, 38), such as printers or finishers. The interface system also includes a sheet position sensing system (52) and a sheet transporting system (42). The transporting system provides selectable flexible media translation for selectably transporting flexible media from selected ones of the plurality of flexible media input areas to selected ones of the plurality of flexible media output areas so as to provide selectable flexible media feeding from selected flexible media input processors to selected flexible media output processors.

Abstract: More accurately correcting sheet position and skew in a desired print media sheet trajectory in a printer paper path, with a registration system including sheet drive nips defined by laterally spaced and differentially driven elastomer surfaced frictional sheet drive rollers and mating undriven idler rollers have a non-slip rotational sheet engagement. The undriven idler rollers have rotary encoders producing encoder signals corresponding to their rotation by a sheet in the nip, which encoder signals are provided to a controller for the registration system to control forward and differential drive motor systems for the sheet drive rollers so as to substantially correct for errors in the desired trajectory of said sheet by sheet drag forces acting on the elastomer surfaced sheet drive rollers in the sheet drive nips.

Abstract: A multifunction printed sheets interface system with plural sheet input areas for receiving printed sheets from plural printers, plural sheet outputs areas for plural outputs to different sheet processing systems, a sheet position sensing system, and a sheet transporting system providing selectable sheet translation from selected plural sheet input areas to selected plural sheet outputs areas so as to provide selectable sheet feeding from selected printers to selected sheet processing systems, and selectable sheet rotation of selected sheets and selectable sheet merging in a selected sheet sequence of sheets from plural printers. The sheet transporting system has a large planar area with a multiplicity of spaced apart independently operable variable sheet feeding direction and sheet velocity sheet transports, larger than the dimensions of any sheet to be fed thereon to allow simultaneous plural sheet variable transport thereon.

Abstract: A method for improving color-to-color registration in a printing device. The method includes printing a plurality of multi-color images, measuring the relative locations of a first portion of each multi-color image having a first color of each image and a second portion of each multi-color image having a second color of each image, for each image, comparing at least one difference between the first portion's location and the second portion's location with at least one desired difference between the first portion's location and the second portion's location to generate a list of positional errors, using a least square regression analysis of the list of positional errors to determine shift amounts required for placement of each first portion in subsequently generated images to within a desired degree of accuracy, and adjusting the placement of the first portion of each subsequently generated image by the determined shift amounts.

Abstract: An integrated printing system is provided and includes at least two generally vertically aligned image marking engines and at least two generally horizontally aligned image marking engines. The printing system further includes at least one generally horizontal interface media transport for transporting media between and to the vertically aligned and the horizontally aligned image marking engines.

Abstract: An imaging device for producing multicolor images from image data containing data representing an image of a first color and an image of a second color to be registered relative to the image of the first color onto a substrate by transferring toner of the first and second colors to the substrate is provided. The imaging device includes a first imager, a second imager, a photoreceptor belt, a plurality of rollers mounted to a frame of the imaging device, an angular position sensor, an image data source and a controller. The plurality of rollers define a process path along which the photoreceptor belt is driven past the first and second imagers in a process direction. The plurality of rollers includes a drive roller that exhibits an eccentricity for which a formula relating angular position as a function of the phase angle of the drive roller to eccentricity is known. The angular position sensor detects the phase angle of the drive roller.

Abstract: Parallel printing systems and methods incorporate inverter assemblies for not only inverting media during transport through the system but also to register the media or provide a velocity buffer transports with different drive velocities. The inverter assemblies can include the capability to optionally deskew the media and provide lateral registration corrections. The inverter assembly nip rollers are sufficiently spaced from process drive nip rollers to decouple a document in the inverter assembly from the highway paths. The method comprises combining the inverting function selectively with either the registering or the velocity buffering functions.

Abstract: A system for automatically releasing selected plural sheet feeding nip sets spaced along a print media sheet feeding path of a printer, wherein the idler rollers are rotatably mounted on common idler shafts and a selectable partial rotation system driven by a single low cost motor is flexibly connected to those plural idler shafts to partially rotate eccentric lift cams on each idler shaft into the underlying surface as to lift the idler shaft and thereby move the idler rollers away from their normally mating sheet feed rollers to release all the sheet feeding nips, enabling sheet deskew, inversion, acceleration, deceleration, or sheet jam clearance in that selected area of the sheet feeding path.

Abstract: A free sheet, high speed, color tandem printing system that controls registration of images from one imager to another while mechanically decoupling individual imagers and all the while maintaining relative registration of each of the color separations by the use of spherical transport servo devices or spherical nips (SNIPS). SNIPS correct skew, lateral, and process positions and ensure proper registration of a sheet with a station.