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:
Jul. 16, 1985
Filed:
Nov. 23, 1984
Fuchio Kanno, Yokohama, JP;
Koji Sakamoto, Tokyo, JP;
Kazuo Kobayashi, Kawasaki, JP;
Wataru Yasuda, Yokohama, JP;
Hiromi Ogiyama, Tokyo, JP;
Ricoh Co., Ltd., , JP;
Abstract
A device for forming a toner film for use in developing an electrostatic latent image on an image bearing member, such as photosensitive member, is provided. A developing sleeve is rotatably provided and a magnet roll is also rotatably provided inside of the sleeve for magnetically attracting a blade of magnetic material to the outer peripheral surface of the sleeve thereby causing the toner carried on the sleeve to be formed into a film of desired thickness and charge. The magnet roll is formed with a plurality of magnetic poles elongated axially and arranged along the periphery of the roll in alternating polarities. Thus, the magnetic attractive force applied by the magnet roll to the blade changes periodically. In the present invention, the frequency of alternating magnetic field applied to the blade is set to be larger than the first order resonant frequency of the blade, thereby allowing to maintain the applied magnetic force as constant as possible.