US5164870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head employing a magnetic gap material composed of Cr2 O3
Assignee: Canon Electronics Inc
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Filing: 1991-06-25
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Granted: 1992-11-17
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Expires: 2011-06-25
Abstract
Abstract A magnetic head comprises a pair of magnetic core half parts abutted to each other and having magnetic alloy films on both abutted surfaces, a magnetic gap material composed of laminated films formed on the abutted surface of at least one of the pair of magnetic core half parts, and welding glass welding the pair of magnetic core half parts. The laminated films are composed of an SiO 2 film and a Cr 2 O 3 film located in sequence from the magnetic core half part side. The laminated films serve to protect the magnetic alloy film from an erosion due to the welding glass. The Cr 2 O 3 film ofers excellent wettability by the welding glass, thereby improving the strength of the magnetic head.
Inventors
- 👤 Minoru Kato
- 👤 Michio Yanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:13
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/235
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
268 words
A magnetic head comprising: first and second abutting magnetic core half parts, each of said first and second magnetic core half parts having a reference surface and an opposing surface extending in a direction perpendicular to said reference surface, said reference surfaces being coplanar and each of the opposing surfaces of said first and second magnetic core half parts having a first portion parallel to a corresponding first portion of the opposing surface of the other magnetic core half part and a second portion which is not parallel to said first portions; Cr 2 O 3 films formed on the first and second portions of the opposing surfaces of said first and second magnetic core half parts to form a magnetic gap aligned along the first portions of said opposing surfaces, the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces extending from the Cr 2 O 3 films formed on the first portion of the corresponding opposing surface to the corresponding reference surface, the opposed Cr 2 O 3 films formed on said first portions serve as magnetic material, said magnetic gap being operable for recording and/or reproducing signals on and/or from a magnetic recording medium; and a welding member interposed between the second portions of said first and second opposing surfaces for welding together said first and second magnetic core half parts, said welding member comprising a welding glass for welding said first and second magnetic core half parts through the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces.
Claim 2
Dependent Claim
268 words
A magnetic head comprising: first and second abutting magnetic core half parts, each of said first and second magnetic core half parts having a reference surface and an opposing surface extending in a direction perpendicular to said reference surface, said reference surfaces being coplanar and each of the opposing surfaces of said first and second magnetic core half parts having a first portion parallel to a corresponding first portion of the opposing surface of the other magnetic core half part and a second portion which is not parallel to said first portions; Cr 2 O 3 films formed on the first and second portions of the opposing surfaces of said first and second magnetic core half parts to form a magnetic gap aligned along the first portions of said opposing surfaces, the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces extending from the Cr 2 O 3 films formed on the first portion of the corresponding opposing surface to the corresponding reference surface, the opposed Cr 2 O 3 films formed on said first portions serve as magnetic material, said magnetic gap being operable for recording and/or reproducing signals on and/or from a magnetic recording medium; and a welding member interposed between the second portions of said first and second opposing surfaces for welding together said first and second magnetic core half parts, said welding member comprising a welding glass for welding said first and second magnetic core half parts through the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces.
Claim 3
Dependent Claim
41 words
A magnetic head as claimed in claim 1, wherein each of said first and second magnetic core half parts is made of ferrite, and a magnetic alloy film having a high saturation magnetization is disposed on each of said opposing surfaces.
Claim 4
Dependent Claim
26 words
A magnetic head as claimed in claim 1, wherein the Cr 2 O 3 films formed on the first portions of said opposing surfaces are contiguous.
Claim 5
Dependent Claim
30 words
A magnetic head as claimed in claim 1, wherein no non-magnetic layer is interposed between said first and second magnetic core half parts and said Cr 2 O 3 films.
Claim 6
Dependent Claim
272 words
A magnetic head comprising: first and second abutting magnetic core half parts, each of said first and second magnetic core half parts having a reference surface and an opposing surface extending in a direction perpendicular to said reference surface, said reference surfaces being coplanar and each of the opposing surfaces of said first and second magnetic core half parts having a first portion parallel to a corresponding first portion of the opposing surface of the other magnetic core half part and a second portion which is not parallel to said first portions; laminated films comprising Cr 2 O 3 and SiO 2 films formed on the first and second portions of the opposing surfaces of said first and second magnetic core half parts to form a magnetic gap aligned along the first portions of said opposing surfaces, the opposed Cr 2 O 3 films formed on said first portions serve as magnetic gap material, the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces extending from the Cr 2 O 3 films formed on the first portion of the corresponding opposing surface to the corresponding reference surface, said magnetic gap being operable for recording and/or reproducing signals on and/or from a magnetic recording medium; and a welding member interposed between the second portions of said first and second opposing surfaces for welding together said first and second magnetic core half parts, said welding member comprising a welding glass for welding said first and second magnetic core half parts through the laminated films formed on the second portions of said first and second opposing surfaces.
Claim 7
Dependent Claim
272 words
A magnetic head comprising: first and second abutting magnetic core half parts, each of said first and second magnetic core half parts having a reference surface and an opposing surface extending in a direction perpendicular to said reference surface, said reference surfaces being coplanar and each of the opposing surfaces of said first and second magnetic core half parts having a first portion parallel to a corresponding first portion of the opposing surface of the other magnetic core half part and a second portion which is not parallel to said first portions; laminated films comprising Cr 2 O 3 and SiO 2 films formed on the first and second portions of the opposing surfaces of said first and second magnetic core half parts to form a magnetic gap aligned along the first portions of said opposing surfaces, the opposed Cr 2 O 3 films formed on said first portions serve as magnetic gap material, the Cr 2 O 3 films formed on the second portions of said first and second opposing surfaces extending from the Cr 2 O 3 films formed on the first portion of the corresponding opposing surface to the corresponding reference surface, said magnetic gap being operable for recording and/or reproducing signals on and/or from a magnetic recording medium; and a welding member interposed between the second portions of said first and second opposing surfaces for welding together said first and second magnetic core half parts, said welding member comprising a welding glass for welding said first and second magnetic core half parts through the laminated films formed on the second portions of said first and second opposing surfaces.
Claim 8
Dependent Claim
41 words
A magnetic head as claimed in claim 5, wherein each of said first and second magnetic core half parts is made of ferrite and a magnetic alloy film having a high saturation magnetization is disposed on each of said opposing surfaces.
Claim 9
Dependent Claim
28 words
A magnetic head as claimed in claim 5, wherein each of said Cr 2 O 3 films has a thickness range from approximately 100 Å to 200 Å.
Claim 10
Dependent Claim
26 words
A magnetic head as claimed in claim 5, wherein the Cr 2 O 3 films formed on the first portions of said opposing surfaces are contiguous.
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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) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |