Patent ID: 7520504

Claim:
A paper processing device, comprising: a processing unit which performs predetermined processing upon sheets of paper which are being conveyed one at a time along a paper conveyance direction; a paper ejection roller which discharges the sheets of paper, after completion of processing by the processing unit, in the paper conveyance direction; a sorting mechanism which shifts the paper ejection roller to and fro along a rotation shaft between an initial position and a sorting position in a direction which is orthogonal to the paper conveyance direction; a paper overlapping mechanism which superimposes, between the processing unit and the paper ejection roller in the paper conveyance direction, a predetermined number of sheets of paper upon which processing has been completed; and a control unit which is adapted to control the operation of the sorting mechanism and the paper overlapping mechanism; wherein the paper overlapping mechanism comprises a plurality of retention units which branch off along the paper conveyance direction from between the processing unit and the paper election roller; and, after each of a plurality of sheets of paper, upon which processing by the processing unit has been completed, has been stored by a corresponding one of the plurality of retention units, they are discharged by each of the plurality of retention units into the paper conveyance direction between the processing unit and the paper election roller as mutually superimposed; and wherein the control unit is adapted to superimpose a predetermined number of sheets of paper by operating the paper overlapping mechanism, before shifting the paper ejection roller from the initial position to the sorting position with the sorting mechanism.