Dynamic magnetic information storage or retrieval – Head – Magnetoresistive reproducing head
Reexamination Certificate
1999-05-24
2002-06-18
Ometz, David L. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head
Magnetoresistive reproducing head
C360S319000
Reexamination Certificate
active
06407891
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to read/write magnetic head assemblies, and more particularly to devices for canceling unwanted electromagnetic fields within such heads.
2. Description of the Prior Art
In a conventional hard-disk drive (HDD) utilizing so-called MR heads as the recording transducer, the recording head typically uses different elements on the head to perform the write and read operations. Writing on the hard-disk is typically performed using an inductive writing head element, and reading back from the hard-disk is typically performed using a read head having a magnetoresistive (MR) element. The inductive write head and the MR element are specially-made structures on the read/write head consisting of layers of specially-deposited thin films. The read head is typically deposited onto the substrate first, and the write head layers are deposited after the deposition of the read head. In other prior art devices the write head layers are deposited first and the read head is deposited after them. In either head configuration significant problems occur because the electromagnetic field generated by the write head can adversely affect the operation of the read head by biasing the MR element. Where the MR element has become biased by exposure to the electromagnetic field of the write head, it produces a noisy signal that ultimately leads to reading errors. A need therefore exists for an improved read/write head wherein the MR element is not exposed to strong electromagnetic fields from the write head. The present invention solves this problem by creating an oppositely directed electromagnetic field at the MR which acts to substantially interfere with and cancel the effects of the electromagnetic field generated by the write head.
SUMMARY OF THE INVENTION
The present invention is a read/write head for writing information to magnetic media and reading information from magnetic media. It includes a write head for writing information onto magnetic media, a read head for reading information from the magnetic media, and an electrical circuit element that is disposed proximate the read head that functions to generate an electromagnetic field at the read head that is generally oppositely directed to the electromagnetic field generated by the write head. The method for operating the read/write head in a hard disk drive, includes the steps of writing data onto a hard disk, while simultaneously generating an electromagnetic field at the read head that is directed oppositely to the electromagnetic field generated by the write head.
It is an advantage of the read/write head of the present invention that electromagnetic field biasing of the read head is reduced.
It is a further advantage of the present invention that an electromagnetic field generating electrical circuit element is disposed proximate the read head to generate an electromagnetic field that substantially interferes with and cancels the electromagnetic field from the write head.
It is yet another advantage of the present invention that an improved read/write head has been developed which utilizes existing manufacturing technology.
It is yet another advantage of the present invention that an improved slider having the improved read/write head disposed thereon, and an improved hard disk drive incorporating the improved slider are made possible through the utilization of the present invention.
These and other features and advantages of the present invention will become fully understood upon reading the following detailed description of the preferred embodiments which makes reference to the several figures of the drawings.
REFERENCES:
patent: 3740736 (1973-06-01), Dion et al.
patent: 4130847 (1978-12-01), Head et al.
patent: 4255772 (1981-03-01), Perez et al.
patent: 4881143 (1989-11-01), Bhattacharyya et al.
patent: 5486967 (1996-01-01), Tanaka et al.
patent: 5583726 (1996-12-01), Mizoshita et al.
patent: 5875080 (1999-02-01), Seagle
patent: 55-64622 (1980-05-01), None
patent: 57-105814 (1982-07-01), None
patent: 58-114321 (1983-07-01), None
patent: 359151334 (1984-08-01), None
patent: 63-138514 (1988-06-01), None
patent: 1-298507 (1989-12-01), None
patent: 04-216311 (1992-08-01), None
patent: 05-225526 (1993-09-01), None
patent: 06-150260 (1994-05-01), None
patent: 06-295418 (1994-10-01), None
patent: 11-31305 (1999-02-01), None
IEEE Transactions on Magnetics, vol. 25, No. 5, Chapman, Sep. 1989, pp. 3686-3688.
Chang Thomas Young
Duan Shanlin
Lam Terence Tin-Lok
Leung Wai C.
Guillot Robert O.
Ometz David L.
Oppenheimer Wolff & Donnelly LLP
LandOfFree
Magnetic read/write head having electromagnetic field... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic read/write head having electromagnetic field..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic read/write head having electromagnetic field... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2937657