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:
Jan. 09, 1979
Filed:
Dec. 30, 1977
William J Bernardelli, Longmont, CO (US);
Allison H Caudill, Lafayette, CO (US);
John A Thompson, Boulder, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An electrophotographic machine of the transfer type in which tetrafluoroethylene-coated carrier beads transport toner particles to a development zone by virute of the triboelectric attraction between positive toner and negative tetrafluoroethylene. At the development zone, the carrier beads are crushed together and occasionally a piece of tetrafluoroethylene is worn off of the surface of the beads and carried along on the surface of the photoconductor. These tetrafluoroethylene-wear products are subjected to high level preclean corona current to reverse the triboelectric negative polarity thereof. In that manner, a positive wear product is made to act as though it was toner and is therefore carried out of the machine on copy paper. In a similar manner, paper dust and other contaminants on the photoconductor surface are subjected to a high level preclean corona current to receive a positive charge for being carried out of the machine on the copy paper.