Servo-controlled automatic document feeder

US4457506A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• William H. Ashbee · Boulder, US
• Mark A. Beran · Niwot, US
• Donald F. Colglazier · Longmont, US
• Donovan M. Janssen · Boulder, US
• John Paul Mantey · Boulder, US
• Ronald J. Martin · Loveland, US
• Gerald P. Patch · Boulder, US
• Larry E. Rittenhouse · Boulder, US
• James A. Valent · Longmont, US

Key dates

• Filing date: Sep 16, 1981
• Grant date: Jul 3, 1984
• Expiry date: Sep 16, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B27/6257
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A servo-controlled recirculating automatic document feeder (RADF) includes a plurality of independently driven document transport devices. A picker mechanism separates documents in seriatim from a stack. An entry turnaround transport device buffers and delivers picked documents to a platen transport device for exposure. After exposure, the document is transported along a simplex or duplex path for duplex or simplex copying. The document is then buffered in an exit turnaround transport device and is subsequently returned to the stack. Each transport device is independently driven by a motor and a closed-loop servo. A common reference oscillator generates source signals for the servo-loops. A microcomputer operates on the source signals and generates reference signals for driving the transport devices.