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. 12, 1994
Filed:
Mar. 11, 1993
Minoru Endoh, Kumagaya, JP;
Koichi Oda, Ageo, JP;
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
Magnet assemblies for installation into a voice coil motor is described. A pair of magnetic pieces are molded into circular arc shapes of different radii and positioned concentrically across a gap. The ends of such the pair of magnet pieces, are joined to a similarly-molded other pair of magnet pieces. The direction of magnetization of the former pair of magnet pieces is reverse that of latter pair of a magnet pieces. On the upper curved surface of each of the two units of lower magnet pieces of smaller radius, a cut plane, for example, is formed in order to provide unbalanced cubic volume between one half and the other half from the center plane of a magnet piece, thus increasing the gap magnetic flux density being generated inside the gap at the sections of larger cubic volume, thereby improving overall evenness of the gap magnetic flux density distribution.