Patent ID: 8639172
Filing Date: 2014-01-28
Classification: G03G

Abstract:
1. A sheet-fed duplex printer, comprising: a pair of impression cylinders each provided on a peripheral surface thereof with a paper gripper for gripping a sheet of paper, one of the impression cylinders being in rotational contact with the other impression cylinder disposed downstream in a direction of rotation of and obliquely below the one impression cylinder, the two impression cylinders being synchronously rotated so that the regions of rotational contact thereof both move downwards, the sheet of paper reversing its printing face when the sheet of paper conveyed following the peripheral surface of the one impression cylinder is conveyed to follow that of the other impression cylinder; a first electrophotographic printing unit disposed opposite to the peripheral surface area of the one impression cylinder which area is upstream in the direction of rotation of the one impression cylinder from the region of rotational contact between the one and the other impression cylinder for printing on one face of the sheet of paper being conveyed following the peripheral surface of the one impression cylinder; a second electrophotographic printing unit disposed opposite to the peripheral surface area of the other impression cylinder which area is downstream in the direction of rotation of the other impression cylinder from the region of rotational contact between the one and the other impression cylinder for printing on the other face of the sheet of paper being conveyed following the peripheral surface of the other impression cylinder; and a cleaning unit disposed opposite to, and adapted to clean, the peripheral surface area of the other impression cylinder, the peripheral surface area of the other impression cylinder being downstream in the direction of its rotation from a position thereon at which the sheet of paper conveyed following the peripheral surface of the other impression cylinder is transferred therefrom downstream in the direction of conveyance of the sheet of paper.