Browse Prior Art Database

TONER CONCENTRATION SENSOR

IP.com Disclosure Number: IPCOM000024787D
Original Publication Date: 1982-Feb-28
Included in the Prior Art Database: 2004-Apr-03
Document File: 2 page(s) / 81K

Publishing Venue

Xerox Disclosure Journal

Abstract

A single coil sensor can be used to measure toner concentration. The toner concentration sensor consists of a coil which is mounted so that developer will fill up the core area of the coil and become the core. The core area is designed so that developer will leave the coil slower than it enters; thus, the core area remains full.

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TONER CONCENTRATION SENSOR William G. Miller

DEVELOPER HOUSING

DEVELOPER

Proposed Classification
U.S. CI. 355/3DD Int. CI. G03g 15/00

NEW PW8

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AD J.

A single coil sensor can be used to measure toner concentration. The toner concentration sensor consists of a coil which is mounted so that developer will fill up the core area of the coil and become the core. The core area is designed so that developer will leave the coil slower than it enters; thus, the core area remains full.

Developer material comprises carrier and toner mixed together. For a fixed volume, the amount of carrier and toner remains constant. As the toner concentration increases, the carrier concentration decreases. A change in the amount of carrier in the core area will change the inductance of the coil. To sense a change in inductance, the coil is part of a tank circuit of a oscillator. A change in inductance of the coil changes the output frequency of the oscillator. One method of implementing this sensor in a copier is shown in the figure with the coil mounted in the developer housing.

Volume 7 Number 1 January/February 1982 37

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TONER CONCENTRATION SENSOR (Cont'd)

The oscillator frequency will vary as a function of the toner concentration of the developer flowing through the coil. The frequency to voltage f/v converter produces a voltage which...