Patent ID: 7631867

Claim:
A closed loop registration method for controlling the skew and lateral position of a sheet that includes a lead edge en route within a predetermined sheet path, comprising: providing a drive system for driving the sheet in a process direction within said predetermined sheet path and controlling sheet skew; providing movable first and second sensors positioned along one side of said predetermined sheet path; moving said first and second sensors laterally with respect to said predetermined sheet path; controlling said lateral moving of said first and second sensors based on a signal from at least one of said first and second sensors; determining an amount of sheet skew based on signals from both of said first and second sensors; controlling the skew of the sheet based on said determined amount of skew; providing third and fourth sensors; using said third and fourth sensors to provide a detection signal indicative of said lead edge of the sheet; and using said detection signal of said third and fourth sensors to perform an open loop skew correction before starting said closed loop skew control.