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. 20, 1988
Filed:
Aug. 31, 1987
Keiji Itaya, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A developing apparatus includes a vessel, set near a photosensitive drum and contains at least two magnetic developers bearing different colors, and at least two developing rollers which are held in the vessel and which deposit the developer on the surface of the photosensitive drum. In the apparatus, each developing roller includes a cylindrical rotatable sleeve prepared from a nonmagnetic material and a fixed magnetic roller received in the sleeve. On the peripheral portion of the magnetic roller, a number of charged magnetic poles with alternating polarities are arranged on such a manner that the polarity of the poles facing each other on the adjacent developing rollers is the same. Matching up polarities in this manner prevents the production of a magnetic flux between the adjacent developing rollers.