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:
Apr. 30, 1991
Filed:
Nov. 29, 1988
Agfa-Gevaert, N.V., Mortsel, BE;
Abstract
Dry toner development of an electrostatic charge pattern on a recording surface is carried out with a dry toner layer formed on a donor member by electrostatic attraction resulting from a DC voltage applied across a gap between the surface of the donor member 22 and the surface of an upstream electrically conductive member 16 covered with a mixture of triboelectrically charged toner particles and magnetic carrier particles, the latter with adhering toner particles being attracted to the electrically conductive member surface by magnetic force and forming thereon a magnetic brush. The DC voltage in the gap causes selective attraction of the toner particles free of magnetic carrier particles and an AC voltage of lower peak magnitude can be superimposed on the DC voltage to set the particles in the gap in vibration and facilitate transfer across the gap. Application of the toner layer from the donor member surface to the recording surface is carried out without substantial relative movement between such surfaces.