US4979064A
Expired / Lapsed
US
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Magnetic recording/playback head comprising a superconducting material
Assignee: Thales SA
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Filing: 1988-10-26
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Granted: 1990-12-18
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Expires: 2008-10-26
Abstract
Abstract In a magnetic head, there is provided, in the gap, a superconducting material that has zero permeability and prevents the passage of the magnetic field in the gap. Various alternative embodiments are used to improve the efficiency of the head by channelling the magnetic flux outside the gap.
Inventors
- 👤 Jean-Claude Mage
- 👤 Jean-Luc Rolland
- 👤 Jean-Paul Castera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:34
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278; G11B5/17; G11B5/187; G11B5/23; G11B5/235; G11B5/31; G11B5/3109; G11B5/312; G11B5/3123; G11B5/3126; G11B5/313; G11B5/3143; G11B5/3159; G11B5/10; G11B5/11
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
90 words
A recording/playback magnetic head comprising: a magnetic circuit formed from two magnetic poles separated by a gap, wherein the set of magnetic poles and the gap are arranged near a recording surface of a magnetic recording medium, further wherein the gap contains at least one layer of superconducting material arranged in a direction substantially perpendicular to the recording surface of the recording medium; and wherein said magnetic circuit comprises a magnetic field induction circuit formed as a thin film of the same superconducting material that is contained within said gap.
Claim 2
Dependent Claim
90 words
A recording/playback magnetic head comprising: a magnetic circuit formed from two magnetic poles separated by a gap, wherein the set of magnetic poles and the gap are arranged near a recording surface of a magnetic recording medium, further wherein the gap contains at least one layer of superconducting material arranged in a direction substantially perpendicular to the recording surface of the recording medium; and wherein said magnetic circuit comprises a magnetic field induction circuit formed as a thin film of the same superconducting material that is contained within said gap.
Claim 3
Dependent Claim
16 words
A magnetic recording/playback head according to claim 1, the gap consisting of a single superconducting material.
Claim 4
Dependent Claim
95 words
A magnetic recording/playback head comprising: a magnetic driving circuit; a single pole provided with a magnetic field induction coil and having a magnetic field emission end comprising an emission face placed near a recording surface of a magnetic recording medium so as to emit a magnetic field perpendicular to the recording surface, comprising at least one sheath made of a superconducting material covering the emission end except for the emission face; and wherein said sheath of superconducting material covers the magnetic driving circuit mean and said magnetic field induction coil except for the emission face.
Claim 5
Dependent Claim
95 words
A magnetic recording/playback head comprising: a magnetic driving circuit; a single pole provided with a magnetic field induction coil and having a magnetic field emission end comprising an emission face placed near a recording surface of a magnetic recording medium so as to emit a magnetic field perpendicular to the recording surface, comprising at least one sheath made of a superconducting material covering the emission end except for the emission face; and wherein said sheath of superconducting material covers the magnetic driving circuit mean and said magnetic field induction coil except for the emission face.
Claim 6
Dependent Claim
24 words
A magnetic recording/playback head according to claim 3, wherein the sheath of magnetic material is a layer enveloping the magnetic circuit and the winding.
Claim 7
Dependent Claim
30 words
A magnetic recording/playback head according to claim 3, wherein the magnetic field emitting end has a contraction, and wherein the sheath of superconducting material fits the shape of this contraction.
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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) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |