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US4571652A
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Magnetic recording and reproducing apparatus
Assignee: Hitachi Ltd
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Filing: 1982-11-24
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Granted: 1986-02-18
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Expires: 2002-11-24
Abstract
Abstract A magnetic recording and reproducing apparatus comprises a magnetic head having magnetic cores in which at least portions thereof in the vicinity of a gap are made of Mn-Zn ferrite single crystal and planes of the magnetic cores forming a principal magnetic circuit are formed by {110} planes of the ferrite and <100> directions contained in the {110} planes are inclined to a surface facing a magnetic recording medium, and means for relatively moving the magnetic recording medium in an opposite and parallel direction to a projection vector on said surface facing said recording medium, of a vector directed from a site far from the surface facing the magnetic recording medium to a site near said surface in the <100> direction projected on the surface facing the magnetic recording medium. The present magnetic recording and reproducing apparatus exhibits both high wear resistance and excellent read/write characteristic.
Inventors
- 👤 Hideo Fujiwara
- 👤 Shigekazu Otomo
- 👤 Kiminari Shinagawa
- 👤 Noriyuki Kumasaka
- 👤 Takeo Yamashita
- 👤 Mitsuhiro Kudo
- 👤 Teizo Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:39
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/193; G11B5/133
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
197 words
A magnetic recording and reproducing apparatus comprising: a magnetic head having a plurality of core member facing each other with a gap being formed therebetween in a surface facing a magnetic recording medium, at least a portion of at least one of said magnetic core members which is in the vicinity of said gap being made of a M n -Z n ferrite single crystal, a {110} plane of at least one M n -Z n ferrite single crystal being substantially parallel to a plane forming a principal magnetic circuit, <100> directions contained in said {110} planes being inclined to said surface facing said magnetic recording medium; with the proviso that when a plurality of said ferrite single crystals have the inclined <100> directions, said <100> directions are inclined in the same directions; and means for relatively sliding said magnetic recording medium in opposite and parallel direction to a projection vector on said surface facing said recording medium, of a vector directed from a site far from said surface to a site near said surface is said <100> direction projected in the sliding direction of said magnetic recording medium in said surface facing said magnetic recording medium.
Claim 2
Dependent Claim
197 words
A magnetic recording and reproducing apparatus comprising: a magnetic head having a plurality of core member facing each other with a gap being formed therebetween in a surface facing a magnetic recording medium, at least a portion of at least one of said magnetic core members which is in the vicinity of said gap being made of a M n -Z n ferrite single crystal, a {110} plane of at least one M n -Z n ferrite single crystal being substantially parallel to a plane forming a principal magnetic circuit, <100> directions contained in said {110} planes being inclined to said surface facing said magnetic recording medium; with the proviso that when a plurality of said ferrite single crystals have the inclined <100> directions, said <100> directions are inclined in the same directions; and means for relatively sliding said magnetic recording medium in opposite and parallel direction to a projection vector on said surface facing said recording medium, of a vector directed from a site far from said surface to a site near said surface is said <100> direction projected in the sliding direction of said magnetic recording medium in said surface facing said magnetic recording medium.
Claim 3
Dependent Claim
61 words
A magnetic recording and reproducing apparatus according to claim 1 wherein only one of said M n -Z n ferrite single crystals has the {110} plane substantially parallel to said plane forming said principal magnetic circuit, and an angle θ between said <100> direction and a direction normal to said surface facing said magnetic recording medium is 5°-40°, 80°-85° or 95°-120°.
Claim 4
Dependent Claim
18 words
A magnetic recording and reproducing apparatus according to claim 2 wherein said angle θ is 10°-35° or 95°-115°.
Claim 5
Dependent Claim
18 words
A magnetic recording and reproducing apparatus according to claim 2 wherein said angle θ is 20°-30° or 95°-105°.
Claim 6
Dependent Claim
18 words
A magnetic recording and reproducing apparatus according to claim 2 wherein said angle θ is 25° or 100°.
Claim 7
Dependent Claim
128 words
A magnetic recording and reproducing apparatus according to any one of claims 2 to 5 wherein said magnetic core members facing each other with said gap being interleaved therebetween comprise an I-shaped core half and a C-shaped core half, at least portions of said I-shaped core half and said C-shaped core half which are in the vicinity of said gap being made of the M n -Z n ferrite single crystal, {100} or {110} plane of the M n -Z n ferrite single crystal of said I-shaped core half being substantially parallel to said surface facing said magnetic recording medium, a {110} plane of the M n -Z n ferrite single crystal of said C-shaped core half being substantially parallel to said plane forming said principal magnetic circuit.
Claim 8
Dependent Claim
61 words
A magnetic recording and reproducing apparatus according to claim 1 wherein at least two of said ferrite single crystals have said {110} planes substantially parallel to said plane forming said principal magnetic circuit, and angles θ and θ' between said <100> directions and a direction normal to said surface facing said magnetic recording medium are 5°-40° or 80°-85° and 95°-120°, respectively.
Claim 9
Dependent Claim
21 words
A magnetic recording and reproducing apparatus according to claim 7 wherein said angles θ and θ' are 10°-35° and 95°-115°, respectively.
Claim 10
Dependent Claim
21 words
A magnetic recording and reproducing apparatus according to claim 7 wherein said angles θ and θ' are 20°-30° and 95°-105°, respectively.
Claim 11
Dependent Claim
21 words
A magnetic recording and reproducing apparatus according to claim 7 wherein said angles θ and θ' are 25° and 100°, respectively.
Claim 12
Dependent Claim
101 words
A magnetic recording and reproducing apparatus according to any one of claims 7 to 10 wherein said magnetic core members facing each other with said gap being interleaved therebetween comprise one I-shaped core member and two C-shaped core members, said C-shaped core members being joined to the opposite sides of said I-shaped core with said gap being interleaved therebetween, at least the portions of said C-shaped core members which are in the vicinity of said gap being made of M n -Z n ferrite single crystal and {110} planes thereof being substantially parallel to said plane forming said principal magnetic circuit.
Claim 13
Dependent Claim
57 words
A magnetic recording and reproducing apparatus according to claim 11 wherein at least a portion of said I-shaped core member which is in the vicinity of said gap is made of M n -Z n ferrite single crystal and a {100} plane or {110} plane thereof is substantially parallel to said surface facing said magnetic recording medium.
Claim 14
Dependent Claim
81 words
A magnetic recording and reproducing apparatus according to claim 11 wherein at least a portion of said I-shaped core member which is in the vicinity of said gap is made of M n -Z n ferrite single crystal and a {110} plane thereof is substantially parallel to said plane forming said principal magnetic circuit and a <100> direction contained in said <110> plane is inclined to said surface facing said magnetic recording medium in the same direction as said C-shaped cores.
Claim 15
Dependent Claim
59 words
A magnetic recording and reproducing apparatus according to any one of claims 1-5 or 7-10 wherein glass having a contraction rate lower than that of ferrite when a temperature is lowered from a glass setting temperature to a room temperature is fused and deposited to portions of said magnetic core members which are in the vicinity of said gap.
Claim 16
Dependent Claim
68 words
A magnetic recording and reproducing apparatus according to any one of claims 1-5 or 7-10 wherein at least a portion of said core members which is in the vicinity of said gap is made of M n -Z n ferrite single crystal and {110} plane thereof is substantially parallel to said plane forming said principal magnetic circuit and side planes of said magnetic core members have polished surfaces.
Claim 17
Dependent Claim
33 words
A magnetic recording and reproducing apparatus according to claim 1 wherein a plurality of said ferrite single crystals have the inclined <100> directions, with said <100> directions being inclined in the same direction.
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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) | 1989-02-17 | 1989-08-19 | 1990-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-17 | 1993-08-19 | 1994-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-17 | 1997-08-19 | 1998-02-18 | $7700.00 | Window Closed / Lapsed |