US 6,059,284 AGranted

Process, lateral and skew sheet positioning apparatus and method

AssigneeXerox Corporation

InventorsBarry M. Wolf, Joannes N. M. deJong, Lloyd A. Williams, Michael J. Savino

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Abstract

An apparatus and method for registering and deskewing a sheet along a sheet path. A pair of drive spheres are located in the sheet path. When a sheet enters the nips formed by the spheres the sheet is driven until it is sensed by a sensor. The drive spheres are driven by a pair of wheels which allow the spheres to rotate about any axis through their center and parallel to the plane of the sheet. The spheres are driven such that the sheet is side registered and deskewed as it is moved along the sheet path. Constant feedback from the sensors to the drive controller allows the sheet to be registered in a very short distance and has the added benefit of self compensation for wear of the drive components. The wide registration and deskewing latitude of the device allows for the use of relatively inexpensive and low accuracy sheet drives preceding the device.

Claims12

Dependent claims

An apparatus for registering and deskewing a sheet along a sheet path, comprising:

an omni-directional in the plane of the sheet drive mechanism, to simultaneously move a sheet transversely to the sheet path and along the sheet path;
a plurality of sensors located along the sheet path, operatively associated with said drive mechanism, to detect the lateral position of a sheet along the sheet path and generate a signal indicative thereof, wherein said omni-directional drive mechanism comprises a first sphere located in the sheet path, a first back up member, in circumferential contact with said sphere to form a nip therewith, a second sphere located in the sheet path, a second back up member, in circumferential contact with said sphere to form a nip therewith, a plurality of paired drive members, each pair of drive members in contact with each said first and second spheres to drive the spheres in an omni-directional manner in the plane of the sheet with respect to the sheet path in response to the signal generated by said sensors, wherein at least one of said paired drive members are continuously biased against each of said first and second spheres so that said drive mechanism is self-compensating for wear;
a transport sensor located in the sheet path to detect the presence of a sheet moving along the sheet path and to generate a signal indicative thereof.

An electrophotographic printing machine having a device for registering and deskewing a sheet along a sheet path, comprising:

an omni directional in the plane of the sheet drive mechanism, to simultaneously move a sheet transversely to the sheet path and along the sheet path;
a plurality of sensors located along the sheet path, operatively associated with said drive mechanism, to detect the lateral position of a sheet along the sheet path and generate a signal indicative thereof, wherein said omni-directional drive mechanism comprises a first sphere located in the sheet path, a first back up member, in circumferential contact with said sphere to form a nip therewith, a second sphere located in the sheet path, a second back up member, in circumferential contact with said sphere to form a nip therewith, a plurality of paired drive members, each pair of drive members in contact with each said first and second spheres to drive the spheres in an omni-directional manner in the plane of the sheet with respect to the sheet path in response to the signal generated by said sensors, wherein at least one of said paired drive members are continuously biased against each of said first and second spheres so that said drive mechanism is self-compensating for wear;
a transport sensor located in the sheet path to detect the presence of a sheet moving along the sheet path and to generate a signal indicative.

Dependencies are inferred from the claim text.