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:
Dec. 11, 2001
Filed:
May. 24, 2000
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing device which prevents bias of a developer caused by an axial magnetic force of a magnet roller, and which can form an image uniform in the axial direction; and a magnet roller for a developing device which is used in the above developing device and is reduced in axial magnetic force. The developing device includes a rotatable sleeve which carries a developer on the surface thereof, a fixed magnet roller which is provided within the sleeve and has a plurality magnetic poles, and a doctor blade which controls the amount of developer carried on the sleeve. The developing device is constructed so that among the plurality of magnetic poles of the magnet roller, the ratio of the axial magnetic flux density to the radial magnetic flux density of a magnetic pole opposing the doctor blade is 2.5/100 or less in a central portion in the axial direction.