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US4635153A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic transducer head

Assignee: Sony Corp
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Filing: 1983-08-29
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Granted: 1987-01-06
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Expires: 2003-08-29
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Abstract

Abstract Magnetic transducer head for perpendicular mode recording is disclosed which comprises a main magnetic pole made of a thin film of soft magnetic material and a pair of guard blocks bonded to the main magnetic pole as a unitary body so as to grip the main magnetic pole from both sides thereof, wherein the guard blocks are each formed of a nonmagnetic material portion extended from a magnetic record medium contact surface to a predetermined position and a magnetic material portion, grooves are formed on bonded boundary surfaces between the nonmagnetic material portions and the magnetic material portions, the grooves for separating auxiliary magnetic pole portions magnetically connected to the main magnetic pole to become auxiliary magnetic poles of a predetermined width from return path portions which become return path of magnetic fluxes from the main magnetic pole, boundary surfaces between the nonmagnetic material portions and the magnetic material portions come apart (diverge away) from the magnetic record medium contact surface at a plane perpendicular to the main magnetic pole formed on a pointed portion of the auxiliary magnetic poles, the grooves are covered with the nonmagnetic material portions over a range from the auxiliary magnetic pole portions to the return path portions and a coil is wound around the main magnetic pole through the grooves.

Inventors

  • 👤 Toshiki Shimamura
  • 👤 Kiyonori Hayakawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 15:39
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 235 words
Magnetic transducer head for perpendicular mode recording comprising: a main magnetic pole made of a thin film of soft magnetic material; and a pair of guard blocks bonded to said main magnetic pole as a unitary body so as to grip said main magnetic pole from both sides thereof, wherein said guard blocks are each formed of a nonmagnetic material portion extended from a magnetic record medium contact surface to a predetermined position, and a magnetic material portion, grooves are formed on bonded boundary surfaces between said nonmagnetic material portions and said magnetic material portions, and spaced from the main magnetic pole by the width of an auxiliary magnetic pole portion, said grooves separating auxiliary magnetic pole portions magnetically connected to said main magnetic pole to become auxiliary magnetic poles of a predetermined width, from return path portions which become the return path of magnetic fluxes from said main magnetic pole, said boundary surfaces between said nonmagnetic material portions and said magnetic material portions diverge away from the plane of said magnetic record medium contact surface and from the plane perpendicular to said main magnetic pole at a pointed portion of said auxiliary magnetic poles adjacent the main pole, said grooves being bridged with said nonmagnetic material portions over a range from said auxiliary magnetic pole portions to said return path portions, and a coil is wound around said main magnetic pole through said grooves.
Claim 2
Dependent Claim 235 words
Magnetic transducer head for perpendicular mode recording comprising: a main magnetic pole made of a thin film of soft magnetic material; and a pair of guard blocks bonded to said main magnetic pole as a unitary body so as to grip said main magnetic pole from both sides thereof, wherein said guard blocks are each formed of a nonmagnetic material portion extended from a magnetic record medium contact surface to a predetermined position, and a magnetic material portion, grooves are formed on bonded boundary surfaces between said nonmagnetic material portions and said magnetic material portions, and spaced from the main magnetic pole by the width of an auxiliary magnetic pole portion, said grooves separating auxiliary magnetic pole portions magnetically connected to said main magnetic pole to become auxiliary magnetic poles of a predetermined width, from return path portions which become the return path of magnetic fluxes from said main magnetic pole, said boundary surfaces between said nonmagnetic material portions and said magnetic material portions diverge away from the plane of said magnetic record medium contact surface and from the plane perpendicular to said main magnetic pole at a pointed portion of said auxiliary magnetic poles adjacent the main pole, said grooves being bridged with said nonmagnetic material portions over a range from said auxiliary magnetic pole portions to said return path portions, and a coil is wound around said main magnetic pole through said grooves.

References Cited (Backward Citations)

US4383284A Cited
DE3120549A1 Cited
JPS5715211A Cited
JPS57111817A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-01-05 1990-07-07 1991-01-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-01-05 1994-07-07 1995-01-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-01-05 1998-07-07 1999-01-06 $7700.00 Window Closed / Lapsed

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