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:
Feb. 08, 2000
Filed:
Feb. 10, 1999
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
In a developing device for visualizing an electrostatic latent image using two-component developer containing toner and magnetic carrier, excellent development will be performed and deterioration of the developer will be prevented. A developer carrier opposite to an image carrier having an electrostatic latent image formed thereon is prepared by forming a thin layer of aluminum with a thickness of 3 .mu.m or less on the peripheral surface of a roll-shaped member made of ferrite, and the surface roughness Rz of the peripheral surface of the foregoing ferrite roll is set to 50 .mu.m or less. N-poles and S-poles are alternately magnetized at a 50-to-250-.mu.m pitch along the peripheral surface of this ferrite roll. These magnetic poles can be magnetized to have uniform intensity because the peripheral surface of the roll has been smoothly finished, and a developer layer having only substantially one layer of the carrier uniformly attracted is formed on the peripheral surface. On the other hand, a magnetic recording layer is provided on a roll-shaped conductive substrate, and its surface may be finished so as to satisfy relation of Rz.ltoreq.50 .mu.m. At this time, the thickness of the magnetic recording layer is desirably set to 200 .mu.m or less.