Automatic Document Feeder Multi-Feed Corrector

Abstract

A paper feed system for use in a printing apparatus that detects multi-feeds and separates all sheets while allowing a single sheet to continue is disclosed. The separation system uses a motor for the separator roller that can be torque controlled, allowing varying torques depending on media type and/or user input. The separation system can also detect multi-feeds, correct them, and ultimately feed one sheet at a time through the automatic document feeder.

We claim: 
     
         1 . A multi-feed separation system in an automatic document feeder, comprising:
 a pick assembly with a pick motor and a pick tire;   a feed belt, wherein the pick tire and the feed belt are driven by the pick motor to move media in a process direction;   a separator roller driven by a separator motor in a direction opposite the process direction to apply a torque to the media;   a multi-feed sensor;   wherein the separator motor torque may be increased when a multi-feed of media is detected to clear the multi-feed.   
     
     
         2 . The system of  claim 1 , wherein the sensor is ultra-sonic. 
     
     
         3 . The system of  claim 1 , wherein the sensor is optical. 
     
     
         4 . The system of  claim 1 , wherein a driving feed belt is mated with a counter-rotating separator roller, and the separator roller is counter-rotated. 
     
     
         5 . The method of  claim 5 , wherein the separator roller is torque controlled with a separator motor current. 
     
     
         6 . A scanning unit of a printer with an automatic document feeder that includes a multi-feed separation system, comprising:
 a scanner unit;   a pick assembly with a pick motor and a pick tire;   a feed belt, wherein the pick tire and the feed belt are driven by the pick motor to move media in a process direction to the scanner unit;   a separator roller driven by a separator motor in a direction opposite the process direction to apply a torque to the media;   a multi-feed sensor;   wherein the separator motor torque may be increased when a multi-feed of media is detected to clear the multi-feed.   
     
     
         7 . The system of  claim 7 , wherein the sensor is ultra-sonic. 
     
     
         8 . The system of  claim 7 , wherein the sensor is optical. 
     
     
         9 . The system of  claim 7 , wherein a driving feed belt is mated with a counter-rotating separator roller, and the separator roller is counter-rotated. 
     
     
         10 . The method of  claim 10 , wherein the separator roller is torque controlled with a motor.