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:
Sep. 14, 2010
Filed:
Oct. 02, 2006
Takeshi Sakamoto, Tokyo, JP;
Nobuya Uchida, Tokyo, JP;
Yoshitomo Tanaka, Tokyo, JP;
Yasuyuki Nakayama, Tokyo, JP;
Takeshi Sakamoto, Tokyo, JP;
Nobuya Uchida, Tokyo, JP;
Yoshitomo Tanaka, Tokyo, JP;
Yasuyuki Nakayama, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A rare-earth magnet having a protective film for enhancing a corrosion resistance is provided. The protective film is a three-layer film including a first protective layer with a crystalline structure α (for example, a polycrystalline structure), a second protective layer with a crystalline structure β (for example, a columnar-crystalline structure), and a third protective layer with the crystalline structure α from the side near a magnet body. Since the adjoining first and second protective layers have different crystalline structures from each other, and the adjoining second and third protective layers have also different crystalline structures from each other, compactness among the three layers in the protective film may be improved. Therefore, development of a pinhole is restrained, and corrosion of the protective film can be restrained.