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US5157569A Expired / Lapsed US ⏱️ 0.0 years remaining

Thin film magnetic head

Assignee: Hitachi Ltd
•
Filing: 1991-05-22
•
Granted: 1992-10-20
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Expires: 2011-05-22
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Abstract

Abstract A magnetic head having a pair of nonmagnetic core base bodies coupled to each other in such a manner that amorphous magnetic alloy films are applied to their abutment surfaces and a gap layer is interposed in a magnetic gap of the head, the films applied to the bodies being made abut against each other at their end edge surfaces each of which has a width larger than its film thickness, and at least one of the bodies having a coil winding groove formed at a portion at which the bodies are coupled to each other. Surface layer portions of each of the bodies, with which a magnetic tape comes into contact, are removed along a direction in which the magnetic tape moves, to a depth which is substantially the same as the depth of the gap while leaving a widthwise portion, which is the same as the track width defined by the width of contact between the two end edge surfaces of the films, at the widthwise center of the bodies, two recesses which are formed by removing the surface layer portions being filled with 2MgO-SiO2 or MgO-SiO2, and another amorphous magnetic alloy film is applied to the inner surface of the coil winding groove which defines a coil winding aperture and the latter film is integrally continued to the former films.

Inventors

  • 👤 Noriyuki Kumasaka
  • 👤 Kenkichi Inada
  • 👤 Ikuo Shinta
  • 👤 Sigeo Imai
  • 👤 Souzou Sasajima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 16:20
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/1871

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 263 words
A magnetic head comprising: a pair of nonmagnetic core base bodies coupled to each other in such a manner that amorphous magnetic alloy films are applied to their abutment surfaces and a gap layer is interposed in a magnetic gap portion of the magnetic head, the amorphous magnetic alloy films applied to the core base bodies being made abut against each other at their end edge surfaces each of which has a width larger than its film thickness, and at least one of the core base bodies having a coil winding groove formed at a portion at which the nonmagnetic core base bodies are coupled to each other wherein: surface layer portions of each of the core base bodies, with which a magnetic tape comes in contact, is removed along a direction, in which the magnetic tape moves, to a depth which- is substantially the same as the depth of the magnetic gap while leaving a widthwise portion, which is the same as the track width defined by the width of contact between the two end edge surfaces of the amorphous magnetic alloy films, at the widthwise center of the core base bodies, two recesses which are formed by removing the surface layer portions being filled with one of forsterite (2MgO--SiO 2 ) and steatite (MgO--SiO 2 ); and another amorphous magnetic alloy film is also applied to the surface of the coil winding groove which defines a coil winding aperture and the latter amorphous magnetic alloy film is integrally continued to the former amorphous magnetic alloy films applied to the abutment surfaces.
Claim 2
Dependent Claim 263 words
A magnetic head comprising: a pair of nonmagnetic core base bodies coupled to each other in such a manner that amorphous magnetic alloy films are applied to their abutment surfaces and a gap layer is interposed in a magnetic gap portion of the magnetic head, the amorphous magnetic alloy films applied to the core base bodies being made abut against each other at their end edge surfaces each of which has a width larger than its film thickness, and at least one of the core base bodies having a coil winding groove formed at a portion at which the nonmagnetic core base bodies are coupled to each other wherein: surface layer portions of each of the core base bodies, with which a magnetic tape comes in contact, is removed along a direction, in which the magnetic tape moves, to a depth which- is substantially the same as the depth of the magnetic gap while leaving a widthwise portion, which is the same as the track width defined by the width of contact between the two end edge surfaces of the amorphous magnetic alloy films, at the widthwise center of the core base bodies, two recesses which are formed by removing the surface layer portions being filled with one of forsterite (2MgO--SiO 2 ) and steatite (MgO--SiO 2 ); and another amorphous magnetic alloy film is also applied to the surface of the coil winding groove which defines a coil winding aperture and the latter amorphous magnetic alloy film is integrally continued to the former amorphous magnetic alloy films applied to the abutment surfaces.
Claim 3
Dependent Claim 46 words
A magnetic head according to claim 1 wherein the abutment surfaces of the pair of nonmagnetic core base bodies, to which the amorphous magnetic alloy films are applied, are arranged to form inclined surfaces extending along the entire length in the lengthwise direction of the surfaces.

References Cited (Backward Citations)

US4656547A Cited
US4819113A Cited
US4866555A Cited
US4916563A Cited
US4969253A Cited
US4985796A Cited
US5031063A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-10-20 1996-04-20 1996-10-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-10-20 2000-04-20 2000-10-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-10-20 2004-04-20 2004-10-20 $7700.00 Window Closed / Lapsed

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