Adjustable automatic process control density patch location detection

摘要

A method and structure that tests a process control patch in an electrophotographic printer by observing/creating a beginning recording medium lead edge location, which establishes a references point on a transportation device. Next, the invention tracks the position of the transport mechanism within the printer by starting a counter triggered by the medium lead edge signal or a virtual medium lead edge signal. The invention then prints the process control patch on the transportation device. The invention identifies positions of the transportation device and process control patch locations once the process control patch passes through a densitometer sensor. The invention establishes a patch testing area determined by a calculated patch trigger point and user configurable sample window parameters. The difference between the threshold-detected leading edge and trailing edge represents the width of the process control patch. The invention tests the calculated patch width for accuracy.