Abstract: A method and system for performing sheet registration are disclosed. Output values for a sheet may be identified within a reference frame. A difference between each output value and a corresponding desired output value may be determined. Input values may be determined based on at least the differences. State feedback values may be determined based on information received from one or more sensors. Acceleration values may be determined for multiple drive rolls based on the input values and the state feedback values. A desired angular velocity for each drive roll may be determined based on the corresponding acceleration value. A motor voltage may be determined for each drive roll that tracks an observed angular velocity value to the desired angular velocity value. The acceleration values may create a linear differential relationship between the input values and the output values. The steps may be performed multiple times.

Abstract: A sheet conveying device which has a reduced size and is capable of detecting the amount of lateral sheet registration deviation and correcting the deviation at high speed. The sheet conveying device includes shift roller pairs for conveying sheets, and a shift unit for shifting a conveyed sheet in a direction orthogonal to a sheet conveying direction. After the sheet has reached a position where it is to be detected by a lateral registration deviation-detecting sensor unit, a CPU causes the sensor unit and the sheet to be shifted in respective opposite directions, detect a sheet lateral edge, and thereby measure the position of the sheet lateral edge. Further, the CPU causes the sheet to be shifted based on a result of the measurement, such that the sheet lateral edge is aligned with a predetermined position.

Abstract: An image forming apparatus has a sheet feeding portion feeding a sheet; a conveyance passage for conveying the sheet inside the apparatus; an image forming portion forming an image on the sheet; a skewing detector disposed in the conveyance passage between the sheet feeding portion and the image forming portion, detecting arrival and departure of the sheet, and detecting skewing amount of the sheet in the conveyance passage; a display portion displaying an apparatus state; a storage portion storing data; and a control portion controlling sheet feeding and conveying, and grasping the sheet skewing amount based on the output of the skewing detector to stop printing when the skewing amount is at or above a first predetermined amount stored in the storage portion.

Abstract: A sheet feeding apparatus includes a regulating member, provided along a feeding path of the sheet, for regulating a widthwise position of a sheet by being abutted by an edge of the sheet A sheet turning mechanism including a first pair of first driving roller and first follower roller for nipping and feeding the sheet is disposed at a position upstream of the regulating member, as is a second pair of second driving roller and second follower roller, where the first pair and the second pair are disposed in a line extending in a widthwise direction of the feeding path, and where the first and the second driving roller are rotatable in opposite directions to turn the sheet to abut the edge of the sheet to the regulating member.

Abstract: A sheet conveying apparatus includes a skew correction unit configured to correct the skew of a sheet while conveying the sheet, controls the skew correction unit to correct the rough skew of the sheet by a first skew correction operation, and accurately correct the reduced skew of the sheet by a second skew correction operation.

Abstract: Positioning in the width direction of a sheet is performed by a skew correcting unit which is provided on a re-conveying path for reversing the sheet and conveying it again to an image forming unit and which has a reference surface that is come into contact with a side edge of the sheet and a plurality of diagonal feed units which obliquely convey the sheet so as to be come into contact with the reference surface. The pressures in nip portions of the other diagonal feed units excluding one of the plural diagonal feed units are reduced or cancelled by a reducing/cancelling unit according to a length in the sheet conveying direction of the sheet which is conveyed.

Abstract: A method of using a buckle for relieving the stresses in sheets caused by differential displacements of drive nips during the registration process includes creating a buckle between pre-registration nips and registration nips. The velocities of the pre-registration nips and registration nips are closely controlled so that the magnitude of buckle between them is large enough to relieve the stresses in the sheet during the registration process, yet small enough to not interfere with the registration process.

Abstract: A transporter is adapted to transport a sheet in a first direction. At least three detectors are disposed at a downstream side of the transporter in the first direction. Each of the detectors is operable to detect passing time of a leading end edge of the sheet. A processor is operable to calculate: a first angle of the sheet with respect to the first direction based on a first difference of the passing time detected by first two of the detectors and a first distance between the first two of the detectors; and a second angle of the sheet with respect to the first direction based on a second difference of the passing time detected by second two of the detectors and a second distance between the second two of the detectors, and operable to detect a jam in case that a value of an angular difference between the first angle and the second angle is larger than a prescribed value.

Abstract: An apparatus for registering a sheet along a transport path, including a plurality of spaced apart sheet feeding nip sets of plural sheet feeding nips in the sheet transport path, the plural sheet feeding nips of the sheet feeding nip sets comprise plural drive wheels and plural mating idlers, steerable drive mechanism for changing the drive wheel to idler alignment to thereby transport the sheet along the paper path while imparting a lateral motion to the sheet as it is transported along the paper path.

Abstract: A curved conveying guiding portion which guides a sheet toward a skew correcting unit is provided on a sheet conveying direction upstream of the skew correcting unit which corrects a skew of the sheet by rotating the sheet while conveying it. By narrowing an interval in the vertical direction in a center portion in the lateral direction of the conveying guiding portion, when a sheet S is rotated and corrected by the skew correcting unit, a load which the sheet to be corrected receives from the conveying guiding portion is reduced.

Abstract: Systems and methods for reducing sheet skew in a document processing device are disclosed. A document processing device may include a plurality of nips, a sheet skew measurement system, a feedback controller and an actuator. Each nip may include an idler wheel and a drive wheel. The sheet skew measurement system may be configured to measure sheet skew for a sheet. The feedback controller may be configured to generate a control signal in response to the sheet skew measured by the sheet skew measurement system. The actuator may be configured to adjust a loading force applied to a sheet by an idler wheel for at least one nip in response to the control signal.

Abstract: A stalled roll registration system and method includes a mechanism that allows for pivoting deskew action in a pre-registration nip in the form of a segmented pre-registration drive roll assembly mounted on a releasable low friction lateral translation carriage. Outer pre-registration idler nips are provided that open to allow a sheet to pivot and close for transport the sheet. The pre-registration idlers are engaged and the drive roll assembly remains locked in the lateral position for initial paper transport up to the stalled registration roll. After the sheet arrives at the stalled registration roll and starts to form a buckle for deskew, the outer pre-registration idlers and carriage are released. The body of the sheet is then free to pivot about the center drive nip and translate in the lateral direction to self align itself with the registration roll.

Abstract: The invention comprises registration roller pairs which detect a skew amount of a sheet being conveyed; registration roller pairs which perform skew correction of the sheet while the sheet is being conveyed; a punch unit which performs punching of the sheet; a punch-unit driving portion which drives the punch unit; a sheet-edge detecting sensor which performs detection of a sheet edge in a direction intersecting with a sheet conveyance direction; a punch-unit moving device which moves the punch unit in the direction intersecting with the sheet conveyance direction; a sheet detecting sensor which performs detection of a sheet position in the sheet conveyance direction; and a controller portion which performs control such that after skew of the sheet is corrected by the registration roller pairs in accordance with detection results of skew amount sensors, and punching is performed on the sheet by the punch-unit moving device and the punch driving portion in accordance with a detection result of the sheet detect

Abstract: The present application is directed to methods and devices for aligning a media sheet in a media feed path of an image forming device. One embodiment includes a drive shaft with skew correction rollers spaced apart on the drive shaft. The media sheet contacts a first skew correction roller and then contacts a second skew correction roller. The drive shaft is then rotated, driving the second skew correction roller and aligning the media sheet to the media feed path.

Abstract: An image forming apparatus provided with a bent sheet feeding guide member in the transportation path for transporting the recording material with the inclination along the width direction of the guide surface configured by the bent sheet feeding guide member being variable, or provided with a pair of transporting rollers that transports a recording material in the transportation path for transporting a recording material with the inclination of the pair of transporting rollers along the axial direction being variable with respect to the transportation surface.

Abstract: A printing system for printing images onto copy sheets and tab stock includes a media registration transport for transporting a media sheet along a path. The printing system further includes a sensing system having a plurality of sensors positioned in line and orthogonal to the feed direction of the sheet path for detecting a leading edge of the media sheet. A control system provides for detecting signals at the times when each of the plurality of sensors are occluded and a control algorithm compares every one of the sensor signals with each other of the sensor signals. The system then identifies at least one pair of sensor signals having inconsistent readings with the other of sensor signals and, determines the presence of a tab on the leading edge based on the inconsistent sensor signal readings and calculates sheet skew based on the other sensor signals.

Abstract: A technique is provided that can realize highly accurate skew correction without employing any particularly complicated device configuration. The quantity of skew of a sheet is determined in accordance with a detection result from a first pair of sensors. Driving of each of first rollers and second rollers is separately controlled to carry the sheet in such a manner as to reduce the quantity of skew determined in accordance with the detection result from the first pair of sensors. The quantity of skew of the sheet is determined in accordance with a detection result from a second pair of sensors. Driving of each of the first rollers and the second rollers is separately controlled to carry the sheet in such a manner as to reduce the quantity of skew determined in accordance with the detection result from the second pair of sensors.

Abstract: A sheet separating mechanism and a method of separating sheets is provided to prevent the multifeeding of sheets into printers or copiers. The sheet separating mechanism provides a first nip and a second nip for feeding a series of sheets therebetween. The first nip can include a first motor and the second nip can include a second motor for feeding a leading sheet from the first nip to the second nip. The mechanism further provides a first sensor for sensing a trailing edge of the leading sheet and a second sensor for sensing a leading edge of the leading sheet. The first sensor is upstream of the first motor and the second sensor is downstream of the second motor. A trailing sheet can be prevented from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor while simultaneously the first sensor remains occluded.

Abstract: A drive control method for a sheet processing machine includes the steps of operating a driving motor of a sheet feed device which feeds a sheet to a sheet processing device that processes the sheet, in synchronism with a rotary member of the sheet processing device, and adjusting a rotary phase of the rotary member of the sheet processing device and a rotary phase of the driving motor of the sheet feed device relative to each other. A drive control apparatus is also disclosed.

Abstract: A method of orienting a sheet in a sheet punching and embossing machine and a sheet punching and embossing machine includes at least one processing station, a machine control system and a sheet transport system including circulating gripper carts with gripper bridges on which grippers are secured. The sheet is gripped and moved through the machine by the grippers. The sheet transport system includes circulating chains. The gripper carts include travel carts which are connected to the sheet transport system, and the gripper carts stop at a respective processing station to process the sheet. The gripper bridge of a gripper cart is connected by spring elements to the travel carts, and the gripper bridge includes a contact surface which can be brought into contact with at least one driven adjustment element of a respective processing station to orient the sheet in the processing station and to lower the gripper bridge into the processing stations.

Abstract: A sheet conveying apparatus has a skew conveying correction roller pair 2 for conveying a sheet, skew conveying detection sensors 3a and 3b for respectively detecting a skew of a sheet and a sheet-end-position detection sensor 4 for detecting the side position of the sheet. The skew conveying correction roller pair 2 is skewed by a skew amount obtained by adding a first skew amount for correcting the skew of a sheet detected by the skew conveying detection sensor 3a and 3b and a second skew amount ?2 for correcting the side position of a sheet detected by the sheet-end-position detection sensor 4. After the sheet is nipped by the skew conveying correction roller pair 2, the skew conveying correction roller pair 2 is skewed by the first skew amount ?1.

Abstract: A scanner including at least a casing, a scanning platform, a carriage and a lateral reversing device is provided. The scanning platform is installed on the covering panel of the casing and is used to accommodate at least one document. The carriage is movably installed in the casing and will transmit a scan-finished signal after having scanned the front side of a document. The lateral reversing device, which is installed at a lateral side of the scanning platform, is equipped with a control unit and is used to turn the document over for the reverse side of the document to be scanned after the control unit has received the scan-finished signal.

Abstract: A method for an automatic document feeder which can control the feeding of a following sheet such that the following sheet can be delayed for a predetermined time when the interval between sheets is shortened, thereby maintaining a constant interval between the sheets. The method and apparatus comprises a paper feeding roller, an arranging roller for arranging a front end of a document being fed by the paper feeding roller and for transferring the document, and an arranging sensor disposed at a front portion of the arranging roller to detect whether the document is being transferred. The arranging sensor detects a rear end of a previous sheet and a front end of a next sheet, and an operation of the arranging roller is controlled using a time interval between the previous sheet and the next sheet.

Abstract: The sheet conveyance apparatus includes a controller which controls a moving unit. The moving unit moves a sheet conveyance unit for conveying a sheet toward a direction intersecting with a sheet conveyance direction. The controller performs the control such that a moving speed of a shift moving unit is reduced when a shift amount of the sheet discharged from an image forming apparatus main body is small. Therefore, generation of a noise and vibration can be suppressed to save electric power consumption. When the shift amount of the sheet is large, the moving speed of the shift moving unit can be increased to shorten an operation time necessary to the movement.

Abstract: A plurality of moving-amount detecting units respectively detects a moving amount of the sheet fed by a feeding unit at a plurality of points in a width direction of the sheet. A skew detecting unit detects a skew of the sheet based on the moving amount of the sheet detected by the moving-amount detecting units.

Abstract: The presently described embodiments are directed to a method and system for improving sheet registration in a document processing device. The presently described embodiments implement a technique the produces accurate results with merely a small tail wag. To do so, the method ultimately establishes or determines a variety of parameters (e.g. lateral position of a sheet, skew, registration time, nominal sheet velocity, and correction velocity). These parameters are then used by the system to calculate a lateral velocity profile. In this regard, the calculated velocity profiles are applied to the wheels or nips, in the paper path. Thus, the wheels can be controlled and will allow for improved sheet registration in the document processing device.

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: A sheet conveying apparatus has a detection unit for detecting an inclination to a sheet conveying direction of a sheet; an inclination correction unit for correcting the inclination of the sheet by rotating which nipping the sheet based on a detection signal from the detection unit; a first conveying unit, which nips and conveys the sheet upstream of the inclination correction unit; a first nipping release unit for releasing a nipping state of the first sheet conveying unit; a second conveying unit which is provided downstream of the inclination correction unit and nips and conveys the sheet; a second nipping release unit for releasing the nipping state of the second sheet conveying unit; and a control unit for controlling the first nipping release unit and the second nipping release unit to selectively release the sheet nipping state of the first sheet conveying unit and the second sheet conveying unit according to an inclination correction operation by the inclination correction unit.

Abstract: The present inventions are a paper skew correcting device and a bill depositing/dispensing apparatus. The paper skew correcting device comprises first and second driving rollers 21 and 22 disposed on the left and right sides of a conveying route for paper 2 and first and second driven rollers 23 and 24 with narrow contact faces placed opposite to the first and second driving rollers 21 and 22 via the conveying route. The second driving roller 22 is formed in a tapered roller with a tapered outer peripheral surface and its rotation shaft 22a is provided aslant so that the contact part of the tapered roller is almost parallel with the conveying route. The second driven roller 24, corresponding to the second driving roller 22, is laterally moved according to the skew angle of the conveyed paper 2 so as to change its contact position with the second driving roller 22 so that the feeding speed of the right side of the paper 2 can be accelerated or decelerated to correct the skew paper.

Abstract: The sheet conveyance apparatus includes a controller which controls a moving unit. The moving unit moves a sheet conveyance unit for conveying a sheet toward a direction intersecting with a sheet conveyance direction. The controller performs the control such that a moving speed of a shift moving unit is reduced when a shift amount of the sheet discharged from an image forming apparatus main body is small. Therefore, generation of a noise and vibration can be suppressed to save electric power consumption. When the shift amount of the sheet is large, the moving speed of the shift moving unit can be increased to shorten an operation time necessary to the movement.

Abstract: There is provided a sheet post-processing unit and image forming unit, which is capable of stably conveying sheets discharged one after another to a tray to form a bundle of sheets and to staple the bundle. A sheet conveying means is provided for selectively conveying the sheet to be discharged in the downstream and upstream directions of the sheet discharging direction, as well as moving the sheet in a direction intersecting the sheet conveying direction, and which is capable of moving up and down to be contactable with, and detachable from, the sheet.

Abstract: Methods and systems for performing sheet registration are described. A device having a plurality of drive rolls may receive a sheet. Each drive roll may operate with an associated angular acceleration. A state vector, including a plurality of state variables, may be identified. Error-space state feedback values may be determined based on a difference between each state variable and a corresponding reference state variable based on a desired sheet trajectory. Control input variable values may be determined based on the error-space feedback values and one or more gains. A motor control signal for a motor for each drive roll may be determined based on the control input variable values and the state variables. Each motor control signal may impart a desired angular acceleration for at least one drive roll. The identifying step and each determining step may be performed repeatedly to register the sheet to the desired trajectory.

Abstract: Methods and systems for performing sheet registration are described. A device having a plurality of drive rolls may receive a sheet. Each drive roll may operate with an associated angular velocity. A state vector, including a plurality of state variables, may be identified. Error-space state feedback values may be determined based on a difference between each state variable and a corresponding reference state variable based on a desired sheet trajectory. Control input variable values may be determined based on the error-space feedback values and one or more gains. A motor control signal for a motor for each drive roll may be determined based on the control input variable values and the state variables. Each motor control signal may impart a desired angular velocity for at least one drive roll. The identifying step and each determining step may be performed repeatedly to register the sheet to the desired trajectory.

Abstract: A medium transport apparatus includes a medium detection sensor having a light-emitting unit and a light-receiving unit that are arranged apart from each other by a predetermined distance, and that changes the signal level of a detection signal output from the light-receiving unit according to the presence/non-presence of a medium between the light-emitting unit and the light-receiving unit, and a medium guide member that is arranged in the middle of a transport path for the medium to guide the medium, and that has a medium guide face for guiding the medium, and a sensor attachment portion to which the medium detection sensor is attached so that the medium guide face may be arranged at a position nearer to one of the light-emitting unit and the light-receiving unit than the other of the light-emitting unit and the light-receiving unit.

Abstract: A registration unit includes a skew correction roller pair configured to rotate a sheet conveyed from a conveyance roller pair and to correct skew of the sheet. The registration unit sheet further includes a projectable swinging guide arranged between the conveyance roller pair and the skew correction roller pair to deflect the sheet. The skew correction roller pair corrects the skew of the sheet deflected by the swinging guide.

Abstract: A system and method of aligning a sheet in a printing device are disclosed. A sheet may be received by a device having a plurality of drive rolls. Each drive roll may have a velocity associated with it. A desired trajectory may be identified and a current position may be identified for the sheet. The velocity of at least one drive roll may be adjusted based on the current position and the desired trajectory. The determining and adjusting operations may be repeated a plurality of times so that the sheet moves along the desired trajectory.

Abstract: According to an embodiment, an idler roller has an insertion through-hole through which a rotation shaft is inserted. Collar-shaped stopper portions are formed on the rotation shaft and are located on both left and right sides of the idler roller when the rotation shaft is inserted and provided at a normal position. Coil springs are attached between the stopper portions and base surfaces of concave groove portions of the idler roller. The idler roller is held at the normal position by biasing force of both the coil springs when paper is not seized. When paper is seized, the idler roller is moved in a lateral direction by elastic restoring force caused by a torsion phenomenon occurring in the paper. The idler roller returns to the normal position due to biasing force of both the coil springs after the paper has passed through the idler roller.

Abstract: The present provides a sheet conveying apparatus for conveying a sheet by sheet conveying device, including detection device which detects a skew of a conveyed sheet with respect to a sheet conveying direction, skew correcting device which pivots, in a state nipping the sheet in a skewed state, in a direction for correcting the skew of the sheet, based on a detection signal from the detection device, and control device provided with calculation device which calculates a front end position of the sheet of which skew is corrected by the pivotal movement of the skew correcting device, based on a detection signal from the detection device.

Abstract: A sheet conveying apparatus for conveying a sheet along a sheet path, has a skew detecting unit for detecting the skew of the sheet being conveyed, a skew correcting unit rotatable in a direction to correct the skew of the sheet in a state nipping the sheet in its skew state, on the basis of a detection signal from the skew detecting unit, a position correcting unit for moving the skew correcting unit in a direction intersecting with the sheet conveying direction, and a controller for controlling so as to move the skew correcting unit in the direction intersecting with the sheet conveying direction by the position correcting unit while conveying the sheet by the skew correcting unit, in order to convey the sheet in a state coincident with the sheet conveying direction when the skew correcting unit is rotated to correct the skew of the sheet and convey the sheet in the rotated state.

Abstract: A sheet feeding apparatus includes a regulating member, provided along a feeding path in a feeding direction of the sheet, for regulating a widthwise position of a sheet by being abutted by an edge of the sheet; a sheet turning mechanism including a first pair of first driving roller and first follower roller for nipping and feeding the sheet disposed at a position upstream of the regulating member and a second pair of second driving roller and second follower roller, wherein the first pair and the second pair are disposed in a line extending in a widthwise direction of the feeding path, and wherein the first driving roller and the second driving roller are notable in opposite directions to turn the sheet to abut the edge of the sheet to the regulating member; and a sheet correcting mechanism disposed downstream of the sheet turning mechanism, and including a feeding roller and a third follower roller for correcting an attitude of the sheet by feeding the sheet so as to abut the edge of the sheet turned by th

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 and to provide a velocity buffer transport with different drive velocities. The inverter assemblies can include the capability to optionally deskew the media while providing lateral (cross-process) registration corrections. The method comprises simultaneously combining the inverting function selectively with deskewing, side registering, and/or velocity buffering functions.

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 sheet conveying apparatus for conveying a sheet using a sheet conveying unit arranged along a sheet conveying path has a skew detecting unit for detecting skew of the sheet conveyed along the sheet conveying path with respect to a sheet conveying direction, a skew correcting unit that moves in a direction for correcting the skew of the skewed sheet with the sheet nipped therein on the basis of a detection signal from the skew detecting unit, and a guide unit for supporting the skew correcting unit and guiding the sheet to the skew correcting unit, in which, when the skew correcting unit moves for correcting the skew of the sheet, the guide unit is moved together with the skew correcting unit to prevent a load from being applied to a trailing edge of the sheet.

Abstract: An apparatus and method are provided for reducing a printing position error, in which the method includes the steps of (a) driving an encoder wheel as many times as a predetermined number of forward counts at a predetermined initial acceleration, thereby making the edge of a printing paper become separated from a sensing unit and conveyed in a forward direction, (b) driving the encoder wheel at the predetermined initial acceleration and conveying the printing paper in a backward direction, (c) calculating a difference value between the number of backward counts of the encoder wheel from a start time of the backward driving to a point when the sensing unit detects the edge of the printing paper and the number of forward counts, and (d) repeating the steps (a) through (c) for a designated number of times while varying the predetermined initial acceleration, and setting an initial acceleration corresponding to a smallest value among the difference values as the initial acceleration for driving the encoder wheel.

Abstract: A method measures the location of a sheet and then moves the sheet to a registered position. By measuring the actual location of the sheet and then moving the sheet to the registered position, the invention saves a substantial amount of time. An elongated array of LED sensors 130 stretches over several inches and is aligned with a collimated light source 110. Each sensor in the array is spaced from its adjacent sensor by a known amount. This amount can be as small as a few tens of thousandths of an inch. The edge of a sheet covers the sensors. The sheet edge is measured and the registration device moves the edge of the sheet to the registered position for receiving the developed image.

Abstract: A roller parallelism adjustment structure is provided for, a roller feeder having, a transfer roller and an impression roller. The transfer and impression rollers are located between the first end and the second end of the roller feed for transferring a material from the first end to the second end. A roller parallelism adjustment mechanism is installed in one side of the roller feeder to support one end of the impression roller and is adjustable relative to the roller feeder to keep the impression roller in parallel to the transfer roller for accurate transfer of the fed material from the first end to the second end.

Abstract: To correct the position of a conveyed item (12) in a conveyance system (10), the deviation of the conveyed item (12) from its target position is detected. If this deviation reveals that a correction is necessary, a suitable correction profile Pi is selected from a plurality of available correction profiles (P1, P2, P3), and the correction is carried out.

Abstract: The invention relates to a method for alignment of individually moved sheet-shaped materials with two individually controlled frictional wheels (A, B), wherein the frictional wheels (A, B) carry out speed changes continuously during the entire process of the alignment according to a control function and in this way achieve a change from the state parameters input angle (?in) and input speed (vin) of the sheet-shaped material, to the state parameters output angle (?out), output speed (vout), X shift (xshift) and Y shift (Yshift).

Abstract: Sheets which are overlapped with an offset are supplied to a device for the continuous alignment of sheets by a stream feeder. After alignment of at least the front edge and one lateral edge of each sheet, the sheets can be transferred downstream to a following device.

Abstract: A method and apparatus for correcting skew of an advancing sheet responsive to the detection of one or the other of aligned fiducial marks located near each of the opposite side edges adjacent the sheet leading edge. Upon detection of a first of the fiducial marks, the advance of the side edge of the sheet associated with the detected fiducial mark is repeatedly dithered rearward and then forward while the opposite side edge of the sheet continues to advance. The dithering of one side edge while continuing the advance of the opposite side edge continues until the other of the fiducial marks is detected after which the advance of the sheet is resumed.