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. 27, 1990
Filed:
Jun. 15, 1989
Hiroshi Murasaki, Osaka, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A developing device including first and second developing sleeves rotatable in the same direction and being disposed adjacent to each other and magnets unrotatable and fixedly mounted in the respective developing sleeves. The first magnet mounted within the first developing sleeve has a first magnetic pole slightly downstream of the position at which the first developing sleeve and the second developing sleeve are closest to each other with respect to the rotational direction of the first developing sleeve. The second magnet mounted within the second developing sleeve has a second magnetic pole slightly upstream of the above-described closest position with respect to the rotational direction of the second developing sleeve. A developer being transported by the first developing sleeve on the peripheral surface thereof is attracted by the second magnetic pole of the second developing sleeve in the region in which the first and second developing sleeves confront each other, thus being transferred easily from the peripheral surface of the first sleeve to that of the second sleeve. A developer being transported by the second developing sleeve on the peripheral surface thereof is attracted by the first magnetic pole of the first developing sleeve in the region in which both developing sleeves confront each other, thus being transferred easily from the peripheral surface of the second sleeve to that of the first sleeve. A repellent magnetic field is generated by the first and second magnetic poles between the region in which both developing sleeves confront each other.