Browse Prior Art Database

INFRARED PAPER THICKNESS SENSOR

IP.com Disclosure Number: IPCOM000027816D
Original Publication Date: 1999-Dec-31
Included in the Prior Art Database: 2004-Apr-09
Document File: 2 page(s) / 88K

Publishing Venue

Xerox Disclosure Journal

Abstract

Disclosed is a paper thickness sensor for electrophotographic printers and copiers. Sensing is based on the optical transmission characteristic of a copy sheet to infrared light. Problems like misfeeds, multiple feeds, jams, and shutdowns encountered in printing machines are due to the various paper bias weight (thickness) used by customers wherein, the machines are not capable of knowing the paper thickness types.

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XEROX DISCLOSURE JOURNAL

INFRARED PAPER THICKNESS SENSOR

Proposed Stephen A. Bonelli Classification

U. S. C1. 399/016 Int. C1. G03g 15/00

Disclosed is a paper thickness sensor for electrophotographic printers and copiers. Sensing is based on the optical transmission characteristic of a copy sheet to infrared light.

Problems like misfeeds, multiple feeds, jams, and shutdowns encountered in printing machines are due to the various paper bias weight (thickness) used by customers wherein, the machines are not capable of knowing the paper thickness types.

The use of an infrared light emitting diode and an infrared detector have been tested in a through beam configuration to detect various paper thickness. The sensor combination successfully detects extreme differences between 13 and 1 10 weight papers of different colors. The information may be applied as an input to a microprocessor to set and control the following machine parameters:

Developer bias voltages

Fuser temperatures

Multi-sheet paper feeding detection.

Charge and detack corotron voltages

Vacuum flow rates in document handlers Angle of cross-roll drive in paper edge registration systems Normal force pressures for paper feeders

REFERENCE

U.S. Patent No. 4,456,372 to Yamauchi describes a copying machine with a document detecting member for detecting either or both the copy density and the size of a document. The document-detecting device having a document-detecting member is arranged under a document glass table and travels over a certain length of...