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:
Feb. 23, 1982
Filed:
Jan. 24, 1980
Chao S Chi, Worcester, MA (US);
Sperry Corporation, New York, NY (US);
Abstract
The transducer for perpendicular magnetic recording comprises a core of high permeability material having a recording pole and a flux return pole spaced apart and connected by an intermediate member forming an inverted generally U-shaped core. The cross sectional area of the flux return pole is substantially greater than that of the recording pole. Current applied to a coil wound around the recording pole generates flux for recording on the magnetic medium. A similarly shaped second core may be disposed on the opposite side of the medium with respect to the first core for providing a flux return path for the first core. A sub-core of high permeability material mounted on the flux return pole forms a gap with the recording pole to provide a ring-type head for data recovery. Current applied to a coil wound on the sub-core saturates the sub-core to render it ineffective during perpendicular magnetic writing. During reading the sub-core winding is de-energized, transforming the perpendicular magnetic recording head into a ring-type reading head. An alternative reading embodiment utilizes magneto-resistive elements disposed between the recording pole and the flux return pole.