Patent ID: 7946569

Claim:
A sheet aligning device, comprising: a transport path configured to transport a stack of a plurality of sheets; a first aligning unit configured to align the stacked plurality of sheets in a first direction in which the stack of sheets is transported on the transport path according to an alignment mode; a second aligning unit configured to align the stacked plurality of sheets in a second direction perpendicular to the first direction on the transport path according to the alignment mode; a thickness acquiring unit configured to acquire a thickness of the stack of sheets; and a mode control unit configured to determine the alignment mode, the alignment mode selected by the mode control unit from a plurality of aligning modes based on at least one property of the stack of sheets, the aligning modes each corresponding to one of a different alignment parameter value of an alignment parameter and a different combination of alignment parameter values of a plurality of alignment parameters, wherein the second aligning unit aligns the stacked plurality of sheets differently in one of the aligning modes than in at least one other of the aligning modes, and the at least one property of the stack of sheets includes at least one of a sheet size, a number of the stacked plurality of sheets, and the thickness of the stack of sheets.