Method for detecting paper feed shingling errors and synchronizing a printer and a feeder

Abstract

A method of synchronizing the feeding and printing of sheets of media, i.e., paper, envelopes, post cards, etc. even though shingled feeds have occurred in the system. The foregoing is accomplished by utilizing two sensors and counters to monitor two sheets of paper to allow two software tasks to stay in synchronization and release the appropriate print data to the printer even when a sheet of paper was not detected in the feeder appears at the print head. The feeder sensor has a counter for its Lead Edge as does the Start of Print Sensor that is in the system's transport paper path. The feeder sensor counter and the start of print counter are incremented and decremented as the paper approaches the sensor and leaves the sensor. If the lead edge counter of the feeder sensor goes negative, then the feeder has shingled and the data for that sheet of paper must be printed.

Dependencies are inferred from the claim text.