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Magnetic recording and reproducing system with composite magnetic head

Assignee: Hitachi Ltd
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Filing: 1985-04-19
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Granted: 1988-03-15
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Expires: 2005-04-19
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Abstract

Abstract The invention discloses a magnetic recording and reproducing system using a composite magnetic head whose surface facing a magnetic recording medium is composed primarily of a ferromagnetic metal and a high permeability ferrite single crystal, and which has a region close to a gap and composed of the ferromagnetic metal, wherein the composite magnetic head is arranged in such a fashion that the {110} plane of the high permeability ferrite single crystal is made to substantially coincide with a plane forming a principal magnetic circuit of the composite magnetic head, that the <100> direction lying inside the {110} plane is inclined at an angle of from 15° to 75° with respect to a direction perpendicular to the surface facing the magnetic recording medium, and that the magnetic recording medium travels in a direction which is relatively the same as, and parallel to, a vector formed by projecting a vector extending from the inside to the outside of the surface facing the magnetic recording medium in the <100> direction, on the surface facing the magnetic recording medium. This magnetic recording and reproducing system can remarkably reduce the step occurring on the surface facing the magnetic recording medium due to wear caused by the travel of the recording medium, and can reduce any output deterioration and fluctuation resulting from the step.

Inventors

  • 👤 Shigekazu Otomo
  • 👤 Noriyuki Kumasaka
  • 👤 Takeo Yamashita
  • 👤 Juichi Morikawa
  • 👤 Takayuki Kobayashi
  • 👤 Mitsuhiro Kudo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 22:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/1875; G11B5/1274

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 244 words
A magnetic recording and reproducing system with a composite magnetic head whose surface facing a magnetic recording medium is composed at least of a ferromagnetic metal and a high permeability ferrite single crystal, and at least whose region close to a gap is composed of said ferromagnetic metal, wherein said composite magnetic head is arranged in such a fashion that the {110} plane of said high permeability ferrite single crystal or a plane inclined from the {110} plane within such a range where the characteristics of the {110} plane are not lost is made to coincide with a plane forming a principal magnetic circuit of said composite head, that the <100> direction lying inside the {110} plane is inclined at an angle within the range of from 15° to 75° with respect to a direction perpendicular to the surface facing said magnetic recording medium, and that said magnetic recording medium travels in a direction which is relatively the same as, and parallel to, a vector formed by projecting a vector extending from the inside to the outside of said surface facing said magnetic recording medium in the <100> direction, on the surface said magnetic recording medium, whereby the difference between the rate of wear of said ferromagnetic metal and the rate of wear of said high permeability ferrite single crystal is reduced, thereby decreasing the level of a step resulting from the travel of said magnetic recording medium and preventing a reduction of output.
Claim 2
Dependent Claim 244 words
A magnetic recording and reproducing system with a composite magnetic head whose surface facing a magnetic recording medium is composed at least of a ferromagnetic metal and a high permeability ferrite single crystal, and at least whose region close to a gap is composed of said ferromagnetic metal, wherein said composite magnetic head is arranged in such a fashion that the {110} plane of said high permeability ferrite single crystal or a plane inclined from the {110} plane within such a range where the characteristics of the {110} plane are not lost is made to coincide with a plane forming a principal magnetic circuit of said composite head, that the <100> direction lying inside the {110} plane is inclined at an angle within the range of from 15° to 75° with respect to a direction perpendicular to the surface facing said magnetic recording medium, and that said magnetic recording medium travels in a direction which is relatively the same as, and parallel to, a vector formed by projecting a vector extending from the inside to the outside of said surface facing said magnetic recording medium in the <100> direction, on the surface said magnetic recording medium, whereby the difference between the rate of wear of said ferromagnetic metal and the rate of wear of said high permeability ferrite single crystal is reduced, thereby decreasing the level of a step resulting from the travel of said magnetic recording medium and preventing a reduction of output.
Claim 3
Dependent Claim 41 words
A magnetic recording and reproducing system according to claim 1 wherein the <100> direction is inclined at an angle within the range of from 25° to 65° with respect to a direction perpendicular to the surface facing said magnetic recording medium.
Claim 4
Dependent Claim 24 words
A magnetic recording and reproducing system according to claim 2 wherein said ferromagnetic metal of said composite magentic head is a ferromagnetic amorphous alloy.
Claim 5
Dependent Claim 24 words
A magnetic recording and reproducing system according to claim 1 wherein said ferromagnetic metal of said composite magnetic head is a ferromagnetic amorphous alloy.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-15 1991-09-14 1992-03-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-15 1995-09-14 1996-03-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-15 1999-09-14 2000-03-15 $7700.00 Window Closed / Lapsed

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