Browse Prior Art Database

Toner Feed Control System

IP.com Disclosure Number: IPCOM000077752D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Boggs, BR: AUTHOR [+3]

Abstract

The feed rate of toner into the developer unit is controlled by comparing the reflectance of an area on the drum seal, which is held at a regulated constant voltage and developed, with the reflectance of a reference shutter. The area on the drum seal is thereafter cleaned at the cleaning station.

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Toner Feed Control System

The feed rate of toner into the developer unit is controlled by comparing the reflectance of an area on the drum seal, which is held at a regulated constant voltage and developed, with the reflectance of a reference shutter. The area on the drum seal is thereafter cleaned at the cleaning station.

Photoconductor drum 1 has a photoconductive element 1a wound therearound for imaging and development of electrostatic images thereon. Drum seal 2 has a highly reflective patch 3, made of conductive material mounted on and insulated from the drum seal. Wire 4 connects conductive patch 3 to the photoconductor advance switch mechanism consisting of plunger 5, insulating sleeve 6, and actuating levers 7 and 8. The switch mechanism effectively becomes a slip ring, through which voltage supplied by copy density adjustment potentiometer 9 may be applied to conductive patch 3.

In operation, patch 3 is held at a constant voltage and developed by magnetic brush 10 as drum 1 rotates in direction of arrow 11. The developed patch is thereafter illuminated by light source 12 and the reflected light is detected by photosensor 13. Shutter 14 is used to shield the photoconductor from the light source and to provide a reflectance reference against which that of patch 3 is compared. Shutter 14 is opened only when patch 3 is passing the optical sensing system.

Compare circuit 15 is responsive to the signal supplied by photosensor 13 to provide a signal to replenish...