Browse Prior Art Database

Device for Feeding and Registering Paper

IP.com Disclosure Number: IPCOM000089183D
Original Publication Date: 1977-Sep-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Bantz, DF: AUTHOR [+2]

Abstract

This article describes a paper feed and registering system which detects the angle of skew of a sheet of paper and adjusts the angle of skew via conventional roller drive means. Detection of skew angle is made either by a fiber-optic detection method or a capacitor plate device. The system can be employed in facsimile scanner, optical character reader or cut sheet printing systems where only a minimal paper skew angle is tolerable.

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Device for Feeding and Registering Paper

This article describes a paper feed and registering system which detects the angle of skew of a sheet of paper and adjusts the angle of skew via conventional roller drive means. Detection of skew angle is made either by a fiber-optic detection method or a capacitor plate device. The system can be employed in facsimile scanner, optical character reader or cut sheet printing systems where only a minimal paper skew angle is tolerable.

Fig. 1 illustrates the fiber-optic detection method for maintaining the paper in registration, with the skew angle at zero, wherein a light source 10 and a cylindrical lens 12 create a line of light across the sensor area 14. The light around the paper 16 is collected through an array of fiber optics 18 and sensed at a photoelectric sensor 20. An operational amplifier 22 with a capacitive feedback detects positive or negative changes in light as the paper moves past the sensor. These changes correspond to paper skews which cause more or less light to be collected at the photosensor 20.

A paper drive control 24 receives the output of the operational amplifier 22, computes the current skew as a function of the skew sensor output, computes the correction required, and applies this correction to the paper roller drive clutches.

Fig. 2 illustrates the capacitor plate detector method for performing skew angle determination in which a pair of plates are used to form a parallel plate capacitor 26. If th...