Stacker having a classifying bullet to shift delivered sheet

Abstract

A stacker has a feed unit for feeding separate sheets in a direction, a stacking unit for stacking the separate sheets in a normal position, and a sheet classifying mechanism for shifting a sheet into a position different from the normal position, upstream of the stacking unit with respect to the direction. Sheets to be used to classify respective batches of sheets stacked by the stacking unit can selectively be shifted into the position different from the normal position by the sheet classifying mechanism. Since those shifted sheets can easily and clearly be recognized by the operator, the batches of stacked sheet can be sorted out with ease. The sheets remain sightly in appearance as no classifying ink mark is applied to those sheets used to classify the batches of stacked sheets. If a bar code printed on a sheet is found defective as a result of a verification process, it may be either shifted into the position different from the normal position or rejected so that it will not be stacked by the stacking unit.