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:
Oct. 20, 1992
Filed:
Jun. 29, 1990
Harold B Shukovsky, Framingham, MA (US);
Sharat Batra, Shrewsbury, MA (US);
Michael L Mallary, Berlin, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A thin film magnetic recording head for high-density recording applications. The head includes a pole formed from at least two ferromagnetic material layers with one layer having high anisotropy (H.sub.k) and low permeability (.mu.), and the other layer having low H.sub.k and high .mu.. The high H.sub.k layer provides the lower magnetic impedance flux path in the tip region and the low H.sub.k layer provides the lower magnetic impedance path in the yoke region of the head. A non-magnetic film may be disposed between the layers, with a thickness chosen to minimize domain flux coupling of the two magnetic layers, while allowing magnetic signal flux transfer between layers at an appropriate point between the tip and the yoke. The pole may be sculpted so that the low H.sub.k layer extends only partially into the tip region, or so that the high H.sub.k layer extends only partially into the yoke. Alternatively, the invention may use a laminated, high permeability layer and a homogeneous layer in place of the high H.sub.k and low H.sub.k layers.