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:
Aug. 31, 1999
Filed:
Jan. 08, 1998
Richard B Lewis, Williamson, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
An apparatus and method for non-interactive, dry powder development of electrostatic images including: an image bearing member bearing an electrostatic image; two component developer including toner and permanently magnetized carrier beads, the carrier having average diameter (2a) and magnetization M.sub.b a developer transporting member having a thickness t for transporting a developer layer of the two component developer, the layer spaced close to and out of contact with the image bearing member, and wherein the developer layer is substantially without chains of carrier beads, a multipole magnet member disposed in close proximity behind the transporting member and moving relative to it so as to sweep poles across its surface, the magnet member having a periodic magnetization of spatial frequency k and a peak magnetization M.sub.0 wherein M.sub.b, t, k, and M.sub.0, are chosen such that M.sub.b is sufficiently large to prevent the escape of developer, and a quantity ##EQU1## is greater than about 1/3.