Patent US1721365A successfully refreshed from Google Patents.
Patent US5079662A successfully refreshed from Google Patents.
US5079662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compound magnetic head having a recording head and a reproducing magnetoresitive head integrated therein
Assignee: HGST Japan Ltd
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Filing: 1989-09-27
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Granted: 1992-01-07
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Expires: 2009-09-27
Abstract
Abstract A compound magnetic head includes first and second magnetic poles arranged to face each other to define a recording gap therebetween, a magnetic film arranged between the first and second magnetic poles, a first non-magnetic film arranged between the first magnetic pole and the magnetic film to define a first reproducing gap therebetween, and a second non-magnetic film arranged between the second magnetic pole and the magnetic pole to define a second reproducing gap therebetween. The recording gap and the first and second reproducing gaps have the same width and a common center line of the gap widths parallel to the direction of movement of a magnetic recording medium.
Inventors
- 👤 Kanji Kawakami
- 👤 Yokuo Saitoh
- 👤 Tetsuo Kobayashi
- 👤 Takayoshi Ohtsu
- 👤 Hiroshi Fukui
- 👤 Deceased Koji Yamagata
- 👤 legal representative by Tetsuji Yamagata
- 👤 legal representative by Reiko Yamagata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3967; G11B5/332
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
249 words
A compound magnetic head for recording and reproducing signals to and from a recording medium through a relative movement between the magnetic head and the recording medium, comprising: first and second magnetic poles arranged to face each other to define a recording gap therebetween; a magnetic film arranged between said first and second magnetic poles; a first non-magnetic film arranged between said first magnetic pole and said magnetic film to define a first reproducing gap therebetween; a second non-magnetic film arranged between said second magnetic pole and said magnetic film to define a second reproducing gap therebetween; said recording gap and said first and second reproducing gaps having the same width and a common center line of the gaps parallel to the direction of the relative movement; wherein a distance across a face of said second magnetic pole defines a first recording gap width; wherein said magnetic film is formed by a magnetoresistive effect element, said magnetoresistive effect element having areas extending in the direction of the width on either side of and beyond the recording gap width, and the extended areas including means for canceling the magnetoresistive effect in the regions outside of the recording gap width; and a pair of electrodes connected to and across the width of said extended areas of said magnetoresistive effect element, wherein a potential difference applied to said electrodes produces a current flowing in said magnetoresistive effect element substantially parallel to a plane of the magnetic head opposing the magnetic recording medium.
Claim 2
Dependent Claim
249 words
A compound magnetic head for recording and reproducing signals to and from a recording medium through a relative movement between the magnetic head and the recording medium, comprising: first and second magnetic poles arranged to face each other to define a recording gap therebetween; a magnetic film arranged between said first and second magnetic poles; a first non-magnetic film arranged between said first magnetic pole and said magnetic film to define a first reproducing gap therebetween; a second non-magnetic film arranged between said second magnetic pole and said magnetic film to define a second reproducing gap therebetween; said recording gap and said first and second reproducing gaps having the same width and a common center line of the gaps parallel to the direction of the relative movement; wherein a distance across a face of said second magnetic pole defines a first recording gap width; wherein said magnetic film is formed by a magnetoresistive effect element, said magnetoresistive effect element having areas extending in the direction of the width on either side of and beyond the recording gap width, and the extended areas including means for canceling the magnetoresistive effect in the regions outside of the recording gap width; and a pair of electrodes connected to and across the width of said extended areas of said magnetoresistive effect element, wherein a potential difference applied to said electrodes produces a current flowing in said magnetoresistive effect element substantially parallel to a plane of the magnetic head opposing the magnetic recording medium.
Claim 3
Dependent Claim
40 words
A compound magnetic head according to claim 1, wherein said means for cancelling the function of the magnetoresistive effect includes good conductors having a small electric resistivity contacted to the extended areas, said electrodes being connected to said good conductors.
Claim 4
Dependent Claim
39 words
A compound magnetic head according to claim 1, wherein the extended areas of said magnetoresistive effect element are made of a base material ion-implanted with another element to make the base material have high coercive force or low permeability.
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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) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |