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:
Mar. 13, 1984
Filed:
Mar. 11, 1982
Keitaro Yamashita, Saitama, JP;
Hiromi Kashiwagi, Kumagaya, JP;
Hitachi Metals, Ltd., , US;
Abstract
A developing apparatus includes a rotatable photosensitive drum having a peripheral surface carrying an electrostatic latent image to be developed. A plurality of developing rolls are disposed in opposition to the photosensitive drum, with developing gaps being formed between the developing rolls and the drum. Each of the developing rolls is constituted by a rotatable cylindrical sleeve of a non-magnetic material and a permanent magnet, stationarily disposed within the cylindrical sleeve, having a plurality of magnetic poles formed on the peripheral surface thereof. By rotating the sleeves in the same direction, developer is transferred from one to another developing roll while forming magnetic brushes which slidably contact the drum surface at the gaps. The latent image is developed by the magnetic brushes. To assure the positive transfer of developer, the magnetic poles of the adjacent developing rolls, positioned in opposition and closest to each other, are magnetized in opposite polarities and one or both of these magnetic poles are positioned, as viewed in the rotating direction of the associated sleeves, upstream of the position at which the adjacent developing rolls come closest to each other.