Browse Prior Art Database

PAPER SENSOR

IP.com Disclosure Number: IPCOM000024324D
Original Publication Date: 1980-Apr-30
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 58K

Publishing Venue

Xerox Disclosure Journal

Abstract

A simple and inexpensive paper sensor is disclosed. As shown in the drawing, the paper sensor comprises an infrared light-emitting diode (emitter) 12 and a photodetector 14, both bonded to a piece of glass 10 with transparent optical cement. The entire device is placed in the paper path 16 with the bottom surface 18 of the glass beveled or slanted so that it is slightly into the paper path to obtain a wiping action by the moving paper to keep the glass surface clean. The wedge shape of the glass, together with the lateral in-line placement of the emitter and photodetector, serve to prevent the reflection from the glass surface returning to the photodetector 14.

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KEROX DISCLOSURE JOURNAL

PAPER SENSOR Paul R. Spencer Gary R. Skillman

Proposed Classification
U.S. Cl. 271/227 Int. C1. B65h 7/02

I4

A simple and inexpensive paper sensor is disclosed. As shown in the drawing, the paper sensor comprises an infrared light-emitting diode (emitter) 12 and a photodetector 14, both bonded to a piece of glass 10 with transparent optical cement. The entire device is placed in the paper path 16 with the bottom surface 18 of the glass beveled or slanted so that it is slightly into the paper path to obtain a wiping action by the moving paper to keep the glass surface clean. The wedge shape of the glass, together with the lateral in-line placement of the emitter and photodetector, serve to prevent the reflection from the glass surface returning to the photodetector 14.

A plurality of emitter and photodetector pairs can be used to obtain electrical redundancy and more reliable detection of paper. Commercially available reflective object sensors'which may be used for the purpose include, Optron OPB 710 and OPB 730, etc.

Volume 5 Number 2 March/April 1980

I 191

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PAPER SENSOR (Cont'd)

The paper sensor of this invention reduces or eliminates alignment problems, has a large ratio of signal with paper to signal without paper, spatial and electrical redundancy, and avoids the problem of dirt accumulation on the glass surface. It is inexpensive and simple to fabricate.

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