US5633770A
Expired / Lapsed
US
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Digital output magnetoresistive (DOMR) head and methods associated therewith
Assignee: MKE-QUANTUM COMPONENTS COLORADO LCC
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Filing: 1996-07-27
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Granted: 1997-05-27
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Expires: 2016-07-27
Abstract
Abstract A digital output magnetoresistive ("DOMR") head for magnetic playback comprising one or more "pinned" magnetic layers having magnetic polar direction which does not rotate under an external field from the media, and a magnetic digital switching layer formed using either shape or crystalline anisotropy such that it has an easy axis parallel to the magnetic direction of the pinned layer or layers and two stable magnetization directions, parallel or antiparallel to the magnetization polar direction of the pinned layer or layers. Because of this dual stable state configuration the DOMR head produces a substantially digital output when reading magnetic information.
Inventors
- 👤 Xiaodong Che
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/008; G11B5/00813; B; B82; B82Y; B82Y10/00; B82Y25/00; G11B5/00847; G11B5/0086; G11B5/012; G11B5/02; G11B5/09; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B15/00; G11B15/02; G11B15/12; G11B15/125; G11B2005/3996
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
186 words
A mass storage device comprising: a magnetic recording medium comprising magnetic transitions stored thereon; a magnetoresistive head supported in close proximity to said recording media comprising a layered structure deposited on a substrate, said layered structure comprising a pinned layer of magnetic material and a digital switching layer of magnetic material separated by a layer of nonmagnetic material, said pinned layer having a substantially fixed magnetization direction, said digital switching layer comprising first and second magnetization directions, said first magnetization direction being substantially parallel to said magnetization direction of said pinned layer after said head passes a first magnetic transition defined on the recording media, and said second magnetization direction being substantially antiparallel to said magnetization direction of said pinned layer after said head passes a subsequent magnetic transition defined on the recording media and manifesting a magnetic field polarity opposite in direction to that of said first magnetic transition; and digital read channel electronics having an input connected to the head for receiving and processing a serial data stream put out by the head during relative movement between the magnetic recording medium and the head.
Claim 2
Dependent Claim
186 words
A mass storage device comprising: a magnetic recording medium comprising magnetic transitions stored thereon; a magnetoresistive head supported in close proximity to said recording media comprising a layered structure deposited on a substrate, said layered structure comprising a pinned layer of magnetic material and a digital switching layer of magnetic material separated by a layer of nonmagnetic material, said pinned layer having a substantially fixed magnetization direction, said digital switching layer comprising first and second magnetization directions, said first magnetization direction being substantially parallel to said magnetization direction of said pinned layer after said head passes a first magnetic transition defined on the recording media, and said second magnetization direction being substantially antiparallel to said magnetization direction of said pinned layer after said head passes a subsequent magnetic transition defined on the recording media and manifesting a magnetic field polarity opposite in direction to that of said first magnetic transition; and digital read channel electronics having an input connected to the head for receiving and processing a serial data stream put out by the head during relative movement between the magnetic recording medium and the head.
Claim 3
Dependent Claim
46 words
The mass storage device of claim 1 wherein an output from the head from its movement relative to said magnetic recording medium is a function of the strength and direction of said magnetic flux from said magnetic domains being read and comprises a substantially digital waveform.
Claim 4
Dependent Claim
21 words
The mass storage device of claim 2 wherein said substantially digital waveform put out by the head follows a non-return-to-zero format.
Claim 5
Dependent Claim
49 words
The mass storage device of claim 1 wherein a mechanism for switching magnetization direction of said digital switching layer comprises shape anisotropy and wherein said digital switching layer comprises a rectangular shape having a length dimension substantially perpendicular to the medium which is approximately twice a width dimension thereof.
Claim 6
Dependent Claim
39 words
The mass storage device of claim 1 wherein a mechanism for switching magnetization direction of said digital switching layer comprises crystalline anisotropy and wherein said digital switching layer of said head comprises an easy axis formed using crystalline anisotropy.
Claim 7
Dependent Claim
28 words
The mass storage device of claim 1 wherein said mass storage device is a disk drive and said magnetic recording medium is a rotating magnetic data storage disk.
Claim 8
Dependent Claim
38 words
The mass storage device of claim 1 wherein the head includes a pinning layer formed adjacent to the pinned layer on the other side of the nonmagnetic layer, for fixing the direction of magnetization of said pinned layer.
Claim 9
Dependent Claim
43 words
The mass storage device of claim 1 wherein the layer of nonmagnetic material comprises a thin film not substantially greater than several atomic thicknesses of a material selected from the group consisting of copper, silver, gold, and alloys including copper, silver or gold.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-26 | 2000-11-25 | 2001-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-26 | 2004-11-25 | 2005-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-26 | 2008-11-25 | 2009-05-27 | $7700.00 | Window Closed / Lapsed |