Patent US2750863A successfully refreshed from Google Patents.
US5227212A
Expired / Lapsed
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Magnetic recording disk, magnetoresistive read head, inductive write head combination
Assignee: HGST Netherlands BV
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Filing: 1991-08-02
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Granted: 1993-07-13
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Expires: 2011-08-02
Abstract
Abstract An improved CoPt based or CoNi based alloy magnetic recording disk for horizontal recording has a magnetic recording layer which is a laminated structure of relatively thin magnetic alloy films separated by relatively thin non-magnetic spacer films. The resulting laminated disk structure has substantially decreased intrinsic media noise at high linear recording densities. A magnetic recording disk drive uses the low noise laminated disk and and a magnetoresistive read sensor to provide a disk drive with significantly reduced noise in the data readback signal.
Inventors
- 👤 Richard H. Ahlert
- 👤 James K. Howard
- 👤 Steven E. Lambert
- 👤 Ian L. Sanders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:52
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/676; G11B5/678; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
131 words
A magnetic recording disk drive for horizontal recording comprising: a magnetic recording disk having a substrate and a laminated magnetic layer formed over the substrate, the laminated magnetic layer comprising alternating films of a magnetic film of a cobalt-based alloy having platinum or nickel present in the alloy and a non-magnetic spacer film, the laminated layer having at least two of said magnetic films and one of said spacer films; means connected to the disk for rotating the disk; a magnetoresistive read head for detecting data recorded in the laminated magnetic layer on the disk; an inductive write head for writing data in the laminated magnetic layer on the disk; and means connected to the read head and the write head for moving the read and write heads across the disk.
Claim 2
Dependent Claim
131 words
A magnetic recording disk drive for horizontal recording comprising: a magnetic recording disk having a substrate and a laminated magnetic layer formed over the substrate, the laminated magnetic layer comprising alternating films of a magnetic film of a cobalt-based alloy having platinum or nickel present in the alloy and a non-magnetic spacer film, the laminated layer having at least two of said magnetic films and one of said spacer films; means connected to the disk for rotating the disk; a magnetoresistive read head for detecting data recorded in the laminated magnetic layer on the disk; an inductive write head for writing data in the laminated magnetic layer on the disk; and means connected to the read head and the write head for moving the read and write heads across the disk.
Claim 3
Dependent Claim
22 words
A disk drive according to claim 1 wherein the disk includes a non-magnetic underlayer between the substrate and the laminated magnetic layer.
Claim 4
Dependent Claim
26 words
A disk drive according to claim 2 wherein the underlayer on the disk is formed of either chromium, molybdenum or an alloy comprising chromium and vanadium.
Claim 5
Dependent Claim
19 words
A disk drive according to claim 1 wherein the magnetic film alloy on the disk includes chromium or molybdenum.
Claim 6
Dependent Claim
27 words
A disk drive according to claim 1 wherein the non-magnetic spacer film on the disk is formed of chromium, molybdenum or an alloy comprising chromium and vanadium.
Claim 7
Dependent Claim
24 words
A disk drive according to claim 1 wherein each of the spacer films on the disk has a thickness less than approximately 80 Angstroms.
Claim 8
Dependent Claim
28 words
A disk drive according to claim 1 wherein the laminated magnetic layer on the disk has a coercivity squareness S* in the range of approximately 0.6 to 0.8.
Claim 9
Dependent Claim
30 words
A disk drive according to claim 1 further comprising means coupled to the magnetoresistive read head for processing the signal representing data detected from the disk by the read head.
Claim 10
Dependent Claim
172 words
A magnetic recording disk drive comprising: a magnetic recording disk for horizontal recording comprising a substrate and a laminated magnetic layer formed over the substrate, the laminated magnetic layer further comprising alternating films of a magnetic film of a cobalt-based alloy having platinum or nickel present in the alloy and a non-magnetic spacer film, the laminated layer having at least two of said magnetic films and one of said spacer films; a hub attached to the disk; a motor connected to the hub for rotating the disk; a magnetoresistive read sensor for reading data from the disk; an inductive write head for writing data to the disk; a carrier for supporting the read sensor and the write head; an actuator connected to the carrier for moving the carrier generally radially across the disk so the read sensor may access different regions of data on the disk; means coupled to the read sensor for processing the signal sensed from the disk by the read sensor; and means for supporting the motor and actuator.
Claim 11
Dependent Claim
172 words
A magnetic recording disk drive comprising: a magnetic recording disk for horizontal recording comprising a substrate and a laminated magnetic layer formed over the substrate, the laminated magnetic layer further comprising alternating films of a magnetic film of a cobalt-based alloy having platinum or nickel present in the alloy and a non-magnetic spacer film, the laminated layer having at least two of said magnetic films and one of said spacer films; a hub attached to the disk; a motor connected to the hub for rotating the disk; a magnetoresistive read sensor for reading data from the disk; an inductive write head for writing data to the disk; a carrier for supporting the read sensor and the write head; an actuator connected to the carrier for moving the carrier generally radially across the disk so the read sensor may access different regions of data on the disk; means coupled to the read sensor for processing the signal sensed from the disk by the read sensor; and means for supporting the motor and actuator.
Claim 12
Dependent Claim
23 words
A disk drive according to claim 9 wherein the disk further comprises a non-magnetic underlayer between the substrate and the laminated magnetic layer.
Claim 13
Dependent Claim
26 words
A disk drive according to claim 9 wherein the underlayer on the disk is formed of either chromium, molybdenum or an alloy comprising chromium and vanadium.
Claim 14
Dependent Claim
19 words
A disk drive according to claim 9 wherein the magnetic film alloy on the disk includes chromium or molybdenum.
Claim 15
Dependent Claim
27 words
A disk drive according to claim 9 wherein the non-magnetic spacer film on the disk is formed of chromium, molybdenum or an alloy comprising chromium and vanadium.
Claim 16
Dependent Claim
24 words
A disk drive according to claim 9 wherein each of the spacer films on the disk has a thickness less than approximately 80 Angstroms.
Claim 17
Dependent Claim
29 words
A disk drive according to claim 9 wherein the laminated magnetic layer on the disk has a coercivity squareness S * in the range of approximately 0.6 to 0.8.
Claim 18
Dependent Claim
30 words
A disk drive according to claim 9 wherein the carrier is an air-bearing slider and wherein the magnetoresistive read sensor is a thin film read sensor formed on the slider.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-12 | 1997-01-11 | 1997-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-12 | 2001-01-11 | 2001-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-12 | 2005-01-11 | 2005-07-13 | $7700.00 | Window Closed / Lapsed |