Method and system for document overlap/gap error detection and correction
AssigneeUnisys Corporation
InventorMichael N. Tranquilla
Life of this patent
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Abstract
A method of document overlap/gap error detection and correction includes detecting a trailing edge of a first document at a feeder, and detecting a leading edge of a second document at an edge detector between the feeder and a transport stage. An overlap/gap error is determined and the feeder is controlled to correct the overlap/gap error, when the error is present. An overlap may be measured before the first document trailing edge arrives at the edge detector, providing a greater remaining length of the second document left in the feeder with which to perform the necessary feeder motions to correct the overlap/gap error.
Claims15
A method of document overlap/gap error detection and correction in a system for feeding and transporting documents, each document having a leading edge and a trailing edge, the system including a feeder stage and a transport stage downstream of the feeder stage for receiving a document from the feeder stage, the feeder stage including a controllable feeder and a separator for receiving the document therebetween, the system including at least one edge detector between the feeder stage and the transport stage for detecting passing document edges during operation of the system, the method comprising:
- detecting a trailing edge of a first document at the feeder;
- detecting a leading edge of a second document at the at least one edge detector, the second document following the first document and the second document still being received between the feeder and the separator when the second document leading edge is detected at the at least one edge detector;
- determining an overlap/gap error, if any, between the first document and the second document based on the first document trailing edge detection and the second document leading edge detection;
- and
- controlling the feeder to correct the overlap/gap error, when the error is present, while the second document is still between the feeder and the separator.
A system for feeding and transporting documents, each document having a leading edge and a trailing edge, the system comprising:
- a feeder stage including a controllable feeder and a separator for receiving documents therebetween, the feeder stage being configured to detect a trailing edge of a first document at the feeder;
- a transport stage downstream of the feeder stage for receiving documents from the feeder stage;
- at least one edge detector between the feeder stage and the transport stage for detecting passing document edges during operation of the system;
- and
- control logic configured to determine an overlap/gap error, if any, between the first document and a second document following the first document based on the first document trailing edge detection and a second document leading edge detection at the at least one edge detector, and to control the feeder to correct the overlap/gap error, when the error is present, while the second document is still between the feeder and the separator.
Dependencies are inferred from the claim text.