US4843506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shields of magnetoresistive transducers
Assignee: HP Inc
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Filing: 1988-06-30
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Granted: 1989-06-27
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Expires: 2008-06-30
Abstract
Abstract An improved shield for field sensing transducers used in magnetic storage devices is presented. The inventive shield provides a planar surface for the transducer to rest on, a single magnetic domain in the vicinity of the transducer, low magnetic reluctance for fields from the recording media, and stability against external magnetic fields, that is, high reluctance for external magnetic fields.
Inventors
- 👤 Hardayal S. Gill
- 👤 Ralph F. Simmons, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:11
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3912; G11B5/10; G11B5/11; G11B5/332
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
An apparatus comprising: a magnetoresistive field sensing transducer having a long axis and a height; and shielding means located adjacent to said field sensing transducer for exposing said transducer to one stable magnetic domain of said shielding means, the shielding means comprising material exhibiting uniaxial anisotropy cut so that its long axis is parallel its magnetic easy, where the shielding means' magnetic easy axis is parallel with the long axis of the field sensing transducer and its height is four times the height of the field sensing transducer.
Claim 2
Independent Claim
88 words
An apparatus comprising: a magnetoresistive field sensing transducer having a long axis and a height; and shielding means located adjacent to said field sensing transducer for exposing said transducer to one stable magnetic domain of said shielding means, the shielding means comprising material exhibiting uniaxial anisotropy cut so that its long axis is parallel its magnetic easy, where the shielding means' magnetic easy axis is parallel with the long axis of the field sensing transducer and its height is four times the height of the field sensing transducer.
Claim 3
Dependent Claim
13 words
An apparatus in claim 1 wherein said shielding means forms a planar surface.
Claim 4
Dependent Claim
23 words
An apparatus as in claim 2 wherein the magnetic easy axis of said plane is parallel to the long dimension of said plane.
Claim 5
Dependent Claim
24 words
An apparatus as in claim 3 wherein the long dimension of said field sensing transducer is parallel to said long dimension of said plane.
Claim 6
Dependent Claim
24 words
An apparatus as in claim 4 wherein the height of said plane is more than four times the height of said field sensing transducer.
Claim 7
Dependent Claim
20 words
An apparatus as in claim 1 wherein said shielding means comprises a high permeability shield for said field sensing transducer.
Claim 8
Dependent Claim
26 words
An apparatus as in claim 6 wherein the height of said plane is greater than the characteristic length of flux decay in said field sensing transducer.
Claim 9
Dependent Claim
19 words
An apparatus as in claim 1 wherein said shielding means comprises a means for resisting magnetization by external fields.
Claim 10
Dependent Claim
32 words
An apparatus as in claim 8 wherein the means to resist magnetization by external fields further comprises increasing the anisotropic field due to the shape and to the material of the shield.
Claim 11
Dependent Claim
44 words
An apparatus as in claim 9 wherein said high permeability shield comprises a first and second plates are made out of Co x M y N z material system, wherein M=Zr, Hf, Ti, Y; N=Nb, Mo, W; X=85 to 92% and Y+Z=8 to 15%.
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) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |