Apparatus and method for controlling a document-handling machine

An apparatus for transporting documents along a document feed path from an upstream end to a downstream end, comprising:

• a stack advance mechanism disposed at the upstream end for advancing the documents from a document stack;
• an input feeder downstream the stack advance mechanism for receiving the documents from the stack advance mechanism and for feeding the documents along the document feed path;
• a first singulator disposed downstream the input feeder for singulating the documents as they are transported from the input feeder;
• a first output feeder disposed downstream the first singulator for taking the documents from the first singulator;
• a conveyor belt running between the first output feeder and the downstream end for conveying the documents downstream along the document feed path after the documents leave the first output feeder;
• an aligning area disposed downstream the first output feeder, through which the documents are bottom-edge aligned as they are conveyed on the conveyor belt;
• a second singulator disposed downstream the aligning area for further singulating the documents as they are transported from the aligning area;
• a second output feeder disposed downstream the second singulator for taking the documents from the second singulator and transporting the documents to the downstream end;
• and
• at least one sensor disposed along the document feed path for sensing the positions of the documents and for generating position signals to control the velocity and acceleration of the stack advance mechanism, the input feeder, first and second singulators, and first and second output feeders so as to coherently control the size of gaps between the documents and maximize document throughput.

A method for transporting documents along a document feed path from an upstream end to a downstream end, comprising the steps of:

• singulating the documents;
• conveying the documents toward the downstream end;
• sensing the positions of the documents;
• generating position signals based on the document positions;
• using the position signals, coherently controlling the velocity and acceleration of the documents along the document feed path so as to regulate the size of the gaps between the documents and to maximize document throughput;
• and
• controlling the velocity and acceleration of a singulator and output feeder disposed downstream the singulator.