The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 2000
Filed:
Dec. 19, 1997
Gary R Marshall, Waterloo, CA;
Alexander S Murison, Waterloo, CA;
NCR Corporation, Dayton, OH (US);
Abstract
A document feeder comprises a tray for containing a stack of documents to be fed along a document feed path. A picker mechanism picks a document from the stack and moves the picked document along the document feed path. A controllable motivator disposed in the tray is provided for, when controlled, applying a variable force against the stack to move the stack against the picker mechanism to allow the picker mechanism to pick a document from the stack and move the picked document along the document feed path. The picker mechanism includes a pre-picker roller having an outer circumferential surface which engages a document in the stack to initially pick the engaged document and move the picked document into the document feed path. First and second interruptive sensors cooperate to sense position of the picking mechanism relative to the stack. A controller responsive to output signals from the first and second sensors controls the motivator to apply a force against the stack such that the stack applies a relatively constant force against the outer circumferential surface of the pre-picker roller. Both sensors are uninterrupted when the stack applies an amount of force less than a desired amount of force against the outer circumferential surface of the pre-picker roller. One sensor is interrupted and the other sensor is uninterrupted when the stack applies a desired amount of force against the outer circumferential surface of the pre-picker roller. Both sensors are interrupted when the stack applies an amount of force greater than a desired amount of force against the outer circumferential surface of the pre-picker roller.