Compensation for skewing of documents during a rotation through a finite angle

Apparatus for rotating a sheet, comprising:

• a conveyance surface on which a sheet, having a first orientation, travels in a first direction;
• first and second rollers for engaging a sheet travelling on said conveyance surface and spaced from each other in a second direction, generally transverse to said first direction;
• first and second drive means, operatively driving said first and second rollers, respectively, independently of each other;
• sensing means for sensing the leading edge of a sheet, having said first orientation, with respect to said rollers;
• control means for controlling the speed and direction of rotation of said drive means in response to said sensing means to rotate the sheet so that it has a predetermined second orientation, a significant angular displacement from the first orientation;
• and
• wherein said sensing means further comprises means for sensing if the leading edge of a sheet is skewed with respect to said second direction, and wherein said control means comprise means, in response to a determination that the leading edge is skew, for controlling the speed and direction of rotation of said drive means to compensate for the skew orientation of the sheet leading edge by adding or subtracting for the significant angular displacement so that the sheet is rotated to the desired predetermined second orientation, with the skew automatically compensated for.