The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1982
Filed:
Sep. 03, 1981
Ben W Fagen, Jr, Rochester, NY (US);
Dale B Parks, Rochester, NY (US);
Bunnington Corporation, Rochester, NY (US);
Abstract
A magnetic brush developing system for electrostatic duplication uses a developer having a magnetic carrier and non-magnetic toner which is transferred by the brush to an electrostatic image. A analog signal is derived using a Hall sensor in contact with the brush and adjacent to a magnet of the brush. The location of the sensor after and downstream of the transfer point provides information in the signal both as to the absolute value of the concentration (ratio of toner to carrier by weight) as well as the rate of transfer of the toner to the electrostatic image. These signals are used to control the supplying of replenishment toner to the developer only when the concentration of toner drops below a predetermined desired value and then at a rate commensurate with the rate of transfer of toner to the electrostatic image.