Patent US4646184A successfully refreshed from Google Patents.
US4646184A
Expired / Lapsed
US
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Magnetic head for recording and reproduction
Assignee: YE Data Inc
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Filing: 1984-09-21
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Granted: 1987-02-24
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Expires: 2004-09-21
Abstract
Abstract There is provided a magnetic head used for both magnetic recording and reproduction thereof, comprising a magnetic head body with a gap portion, wherein a first material having a larger saturated magnetic flux density than that of said body is applied to one or both sides of said gap portion, said gap being internally provided with a second material having a smaller saturated magnetic flux density than said body.
Inventors
- 👤 Tadahiko Goto
- 👤 Hideo Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278; G11B5/187; G11B5/1875; G11B5/1877; G11B5/1878; G11B5/245; G11B5/2452
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
161 words
A magnetic head used for both magnetic recording and reproduction thereof, comprising a magnetic head body with a gap portion, wherein the portion of said body on one side of said gap is a trailing edge side and the portion of the body on the other side of said gap is a front edge side, both edges being defined with reference to the running direction of a medium in proximity to said head, and wherein said gap has an internal portion with two substantially opposed sides, one internal side being on said trailing edge side and one internal side being on said front edge side, and wherein a first material having a larger saturated magnetic flux density than that of said body is applied to one or both sides of said gap portion, at least one of said sides of said internal portion said gap being provided with a second material having a smaller saturated magnetic flux density than said body.
Claim 2
Dependent Claim
161 words
A magnetic head used for both magnetic recording and reproduction thereof, comprising a magnetic head body with a gap portion, wherein the portion of said body on one side of said gap is a trailing edge side and the portion of the body on the other side of said gap is a front edge side, both edges being defined with reference to the running direction of a medium in proximity to said head, and wherein said gap has an internal portion with two substantially opposed sides, one internal side being on said trailing edge side and one internal side being on said front edge side, and wherein a first material having a larger saturated magnetic flux density than that of said body is applied to one or both sides of said gap portion, at least one of said sides of said internal portion said gap being provided with a second material having a smaller saturated magnetic flux density than said body.
Claim 3
Dependent Claim
31 words
The magnetic head according to claim 1 wherein said first material is applied to the trailing edge internal side, and said second material is applied to the front edge internal side.
Claim 4
Dependent Claim
38 words
The magnetic head according to claim 2 wherein said second material has a thickness equal to the difference between the optimum length of gap when used for reproduction and the optimum length of gap when used for recording.
Claim 5
Dependent Claim
28 words
The magnetic head according to claim 2 wherein said body is formed of ferrite, said first material is a metal series material, and said second material is garnet.
Claim 6
Dependent Claim
33 words
The magnetic head according to claim 2 wherein said body is formed of iron-nickel alloy, said first material is iron, iron-aluminum alloy or iron-cobalt alloy and said second material is ferrite or garnet.
Claim 7
Dependent Claim
31 words
The magnetic head according to claim 2 wherein said first material is applied to the trailing edge side and said second material is applied to both sides of said internal portion.
Claim 8
Dependent Claim
38 words
The magnetic head according to claim 6 wherein said second material has a thickness equal to the difference between the optimum length of gap when used for reproduction and the optimum length of gap when used for recording.
Claim 9
Dependent Claim
28 words
The magnetic head according to claim 6 wherein said body is formed of ferrite, said first material is a metal series material, and said second material is garnet.
Claim 10
Dependent Claim
33 words
The magnetic head according to claim 6 wherein said body is formed of iron-nickel alloy, said first material is iron, iron-aluminum alloy or iron-cobalt alloy and said second material is ferrite or garnet.
Claim 11
Dependent Claim
32 words
The magnetic head according to claim 2 wherein said first material is applied to both trailing and front edge sides and said second material is applied to the front edge internal side.
Claim 12
Dependent Claim
38 words
The magnetic head according to claim 10 wherein said second material has a thickness equal to the difference between the optimum length of gap when used for reproduction and the optimum length of gap when used for recording.
Claim 13
Dependent Claim
28 words
The magnetic head according to claim 10 wherein said body is formed of ferrite, said first material is a metal series material, and said second material is garnet.
Claim 14
Dependent Claim
33 words
The magnetic head according to claim 10 wherein said body is formed of iron-nickel alloy, said first material is iron, iron-aluminum alloy or iron-cobalt alloy and said second material is ferrite or garnet.
Claim 15
Dependent Claim
38 words
The magnetic head according to claim 1 wherein said second material has a thickness equal to the difference between the optimum length of gap when used for reproduction and the optimum length of gap when used for recording.
Claim 16
Dependent Claim
28 words
The magnetic head according to claim 1 wherein said body is formed of ferrite, said first material is a metal series material, and said second material is garnet.
Claim 17
Dependent Claim
33 words
The magnetic head according to claim 1 wherein said body is formed of iron-nickel alloy, said first material is iron, iron-aluminum alloy or iron-cobalt alloy, and said second material is ferrite or garnet.
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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) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |