Printer medium or currency thickness / double sheet detection method

Abstract

Media thickness and double sheet detection system includes a CPU for managing input and outputs to/from each operational module, media input handling and storage hardware, a pickup controller manages the input of media from the media input handling and storage hardware into the system, a speed sensor, detecting the speed of the media moving through the system, a thickness sensor detecting the thickness of the media moving through the system, a direction sensor detecting the movement direction of the media through the system, a friction sensor detecting tension of the media when movement of at least one roller that makes up a pair of complimentary pinch rollers is reversed while the other roller is held in a brake position, and a reverse roller and brake roller control module managing the reversal of the least one pinch roller and braking of the complimentary roller.

1 . Media thickness and double sheet detection system, comprising: 
 a CPU for managing input and outputs to/from each operational module;    media input handling and storage hardware;    a pickup controller manages the input of media from the media input handling and storage hardware into the system;    a speed sensor, detecting the speed of the media moving through the system;    a thickness sensor detecting the thickness of the media moving through the system;    a direction sensor detecting the movement direction of the media through the system;    a friction sensor detecting tension of the media when movement of at least one roller that makes up a pair of complimentary pinch rollers is reversed while the other roller is held in a brake position;    a reverse roller and brake roller control module managing the reversal of the least one pinch roller and braking of the complimentary roller.    
   
   
       2 . The system of  claim 1  wherein the speed sensor is used to measure linear media travel through the system based on the number of rotations counted at a continuous feed roller located along the media's path.  
   
   
       3 . The system of  claim 1  wherein upon activation of the thickness sensor, the rollers will stop the forward feed before and prior to reaching the second set of pinch rollers.  
   
   
       4 . The system of  claim 1  wherein at least one of the speed and/or direction sensor is collocated with or on the roller system.  
   
   
       5 . The system of  claim 1  wherein the braking roller is adapted to sense a pinch and stop the reverse motion of the top roller.  
   
   
       6 . The system of  claim 1  wherein free reversal of the top roller signifies a double sheet condition, and wherein the reversal is also noted by the thickness sensor which register a change in media height after a specified distance equivalent to the reversal.  
   
   
       7 . The system of  claim 6  wherein the roller mechanism will again feed in the forward direction if a double feed is not indicated, but if a change was registered on the thickness sensor during reverse feed, the media can be considered double feed and can be diverted through the system as invalid.  
   
   
       8 . Media thickness and double sheet detection within a media dispending system, comprising: 
 media input handling and storage;    a pickup system for moving media from the input handing and storage into a media path within the system, which can provided in the form of a roller mechanism to feed the media down a specified path;    continuous feed rollers deployed along the media path;    a thickness sensor detecting the thickness of the media moving through the system;    a direction sensor detecting the movement direction of the media through the system;    a friction sensor detecting tension of the media when movement of at least one roller that makes up a pair of complimentary pinch rollers is reversed while the other roller is held in a brake position;    a reverse roller and brake roller control module managing the reversal of the least one pinch roller and braking of the complimentary roller.    
   
   
       9 . The system of  claim 8  wherein the continuous feed rollers are provided in the form of top and bottom pinch roller devices deployed along the media's path.  
   
   
       10 . The system of  claim 9  further comprising output hardware deployed at the end of the media's path.  
   
   
       11 . The system of  claim 10  wherein the media output hardware is provided in the form of a slot for at least one of an ATM dispenser or photocopier output tray.  
   
   
       12 . The system of  claim 8 , wherein the media input handing and storage is an input tray.  
   
   
       13 . The system of  claim 12 , wherein the thickness and speed/direction sensors can be located in close proximity to the input tray.  
   
   
       14 . The system of  claim 8  wherein the thickness sensor is at least one of: optical, electronic, mechanical.  
   
   
       15 . The system of  claim 8  wherein the direction sensor is located near the pickup system.  
   
   
       16 . The system of  claim 8  wherein the direction sensor is part of the first set of pinch rollers.  
   
   
       17 . The system of  claim 9  wherein a first set of pinch rollers following at least one of the thickness sensor and/or speed and direction sensor is adapted so that at least one of the top or bottom roller is reversible while the other roller is held in a brake position.  
   
   
       18 . The system of  claim 17 , wherein reversible action by at least one of the rollers and the brake status of the other roller enables the system to measure friction on the surface of the media being moved between the adapted pinch rollers.  
   
   
       19 . A method, comprising the steps of: 
 drawing media from storage into the dispensing system;    measuring linear media travel within the dispensing system;    acquiring first thickness measurement;    stopping media at first and second pinch rollers adapted as a double feed sensor;    reversing direction of the first pinch roller while maintaining a brake condition at the second pinch roller; and    measuring friction on the media using a sensor associated with the second pinch roller;    wherein if friction is measured on the media, continue normal job processing, but if friction is not measured on the media then acquire second thickness measurement and compare to first thickness measurement.    
   
   
       20 . The method of  claim 19 , including the step wherein if second thickness measurement is larger than first thickness measurement, then job is terminated.  
   
   
       21 . The method of  claim 19 , including the step wherein if second thickness measurement is the same as the first thickness measurement, then job is continued.  
   
   
       22 . The method of  claim 19 , including the step wherein if second thickness measurement is larger than first thickness measurement, then the media is redirected.  
   
   
       23 . The method of  claim 19 , including the step wherein if second thickness measurement is larger than first thickness measurement, then the system is recalibrated.  
   
   
       24 . The method of  claim 19 , including the step wherein if second thickness measurement is larger than first thickness measurement, then media is considered double feed and is diverted through the system as invalid.  
   
   
       25 . The method of  claim 19 , wherein the method can be repeated until both friction and consistent height readings are obtained from input media.  
   
   
       26 . The method of  claim 19 , wherein the height measurement will be logged for the job and used to validate all future media processing during that job.