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:
May. 25, 1993
Filed:
Dec. 23, 1991
Fred Schmidlin, Pittsford, NY (US);
John D Sotack, Rochester, NY (US);
William M Lindenfelser, Rochester, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
Direct electrostatic printing apparatus including a cylindrically shaped donor structure for delivering imaging material such as toner particles to a printhead forming an integral part of the printing device. The printhead structure includes control electrodes and a shield electrode structure secured to opposite sides of an insulative base. The donor structure has a relatively small diameter compared to such devices of the prior art making it impossible to deliver adequate quantities of toner to some of the printhead apertures using electrical biasing techniques of the prior art. In the device disclosed, the printhead apertures are biased according to the aperture spacing from the donor structure. The magnitude of the bias or its duration applied to the apertures farther from the donor structure surface is such that toner delivery to those apertures is equal to that of all other apertures.