Abstract: A printing apparatus places multiple images on a sheet, either by re-feeding the sheet through a duplex path back to a marking device, or by feeding the sheet to successive marking devices. An edge position detector upstream of the marking device determines the location of the sheet so that an image may be precisely placed on the sheet. The system ensures that images on both sides of a sheet are in registration with each other.

Abstract: An idler system that is both self-centering and self-aligning with a drive roll. The idler assembly consists of a pair of rolls connected by a shaft, the shaft being supported in a housing. The housing is retained by a resilient spring member which member allows the axis of rotation of the idler rolls to pivot in more than one plane simultaneously. This pivoting causes the axis of rotation of the idler assembly to align parallel with the drive roll axis. The single spring also provides an even loading of the normal force across the width of the drive nip. As a result of the alignment and even loading, skewing of a sheet is prevented as it is driven through the nip formed by the drive roll and the idler roll. The resilient spring mounting also allows for easy replaceability of the idler assembly and the housing is easily locatable between tabs formed in the frame of the machine for mounting the idler assembly therein.

Abstract: A system for decurling a sheet which is being advanced in a predetermined path within a printing machine includes a mechanism for generating a flow of room ambient air. The decurling system further includes a mechanism for directing the flow of room ambient air onto the sheet. Moreover, the decurling system includes a decurler adapted to apply mechanical force to the sheet after the flow of room ambient air has been directed onto the sheet by the directing mechanism. Finally, a mechanism is included for rotating the sheet to advance the sheet to the decurler in a direction substantially perpendicular to the direction of the predetermined path.