US4546398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perpendicular magnetic recording and reproducing head
Assignee: Fujitsu Ltd
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Filing: 1982-07-30
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Granted: 1985-10-08
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Expires: 2002-07-30
Abstract
Abstract A perpendicular magnetic recording and reproducing head, including: a spiral coil of at least one electrically conductive thin film; and a main pole of a first thin magnetic film having an end for recording and reproducing information, the main pole and the spiral coil being electromagnetically coupled to each other. A perpendicular magnetic head such as this can be easily manufactured, can be adapted not only to floppy disks but also to rigid disks, is suitable for high-frequency operation, and has an improved recording/reproducing efficiency.
Inventors
- 👤 Junzo Toda
- 👤 Masao Hiyane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:24
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
153 words
A perpendicular magnetic recording and reproducing head for recording information on and reproducing information from a recording medium having a recording surface, comprising: a first thin magnetic film in substantially perpendicular relation with the recording surface, the first thin magnetic film having a first end, adjacent to the recording surface, which generates a magnetic flux perpendicular to the surface of the recording medium for recording and reproducing information and a second end; a second thin magnetic film having a first portion in substantially parallel relation with the first thin magnetic film and a second portion connected to the second end of the first thin magnetic film; and a thin film coil, disposed in a plane which is substantially parallel to the first thin magnetic film and the first portion of the second thin magnetic film, the thin film coil having a center adjacent to the second end of the first thin magnetic film.
Claim 2
Dependent Claim
153 words
A perpendicular magnetic recording and reproducing head for recording information on and reproducing information from a recording medium having a recording surface, comprising: a first thin magnetic film in substantially perpendicular relation with the recording surface, the first thin magnetic film having a first end, adjacent to the recording surface, which generates a magnetic flux perpendicular to the surface of the recording medium for recording and reproducing information and a second end; a second thin magnetic film having a first portion in substantially parallel relation with the first thin magnetic film and a second portion connected to the second end of the first thin magnetic film; and a thin film coil, disposed in a plane which is substantially parallel to the first thin magnetic film and the first portion of the second thin magnetic film, the thin film coil having a center adjacent to the second end of the first thin magnetic film.
Claim 3
Dependent Claim
31 words
A perpendicular magnetic recording and reproducing head according to claim 1, wherein the thin film coil is a spiral coil and the first thin magnetic film is a mono-magnetic main pole.
Claim 4
Dependent Claim
36 words
A perpendicular magnetic recording and reproducing head according to claim 2, further comprising an insulating film formed between the spiral coil and the main pole and between the spiral coil and the second thin magnetic film.
Claim 5
Dependent Claim
79 words
A perpendicular magnetic recording and reproducing head according to claim 3, wherein the second thin magnetic film has a third portion extending over and in substantially parallel relation to the main pole on the opposite side of the spiral coil from the main pole, the insulating film is formed between the spiral coil and the third portion of the second thin magnetic film and wherein the main pole and the second thin magnetic film form a closed flux structure.
Claim 6
Dependent Claim
51 words
A perpendicular magnetic recording and reproducing head according to claim 3, wherein the main pole has a cross-sectional area and wherein the first end of the main pole has a cross-sectional area which is smaller than the cross-sectional area of the portion of the main pole other than the first end.
Claim 7
Dependent Claim
48 words
A perpendicular magnetic recording and reproducing head according to claim 3, wherein the main pole has a cross-sectional area, the second thin magnetic film has a cross-sectional area, and wherein the cross-sectional area of the second thin film is larger than the cross-sectional area of the main pole.
Claim 8
Dependent Claim
32 words
A perpendicular magnetic recording and reproducing head according to claim 1, 2, 3, 4, 5 or 6, wherein said spiral coil comprises one electrically conductive thin film spirally formed in a plane.
Claim 9
Dependent Claim
58 words
A perpendicular magnetic recording and reproducing head according to claim 1, 2, 3, 4, 5 or 6, wherein said spiral coil comprises a number of stacked thin films each of said stacked thin films being insulated by said insulating film, and each of said thin films having a contact point, said contact point electrically connecting said stacked films.
Claim 10
Dependent Claim
44 words
A perpendicular magnetic recording and reproducing head according to claim 1, 2, 3, 4, 5 or 6, wherein said spiral coil comprises one electrically conductive thin film formed in a helix and wherein the turns of said helix are insulated by said insulating film.
Claim 11
Dependent Claim
167 words
A perpendicular magnetic recording and reproducing head for recording and reproducing information from a recording medium having a recording surface, comprising: a first thin magnetic film in substantially perpendicular relation with the recording surface, the first thin magnetic film having a first end, adjacent to the recording surface, which generates a magnetic flux perpendicular to the surface of the recording medium for recording information, and a second end; a second thin magnetic film having a first portion in substantially parallel relation with the first thin magnetic film and a second portion connected to the second end of the first thin magnetic film; and a magneto resistive element, in substantially parallel relation to the first thin magnetic film, for reproducing information; and a thin film coil, disposed in a plane which is substantially parallel to the first thin magnetic film and the first portion of the second thin magnetic film, the thin film coil having a center adjacent to the second end of the first thin magnetic film.
Claim 12
Dependent Claim
167 words
A perpendicular magnetic recording and reproducing head for recording and reproducing information from a recording medium having a recording surface, comprising: a first thin magnetic film in substantially perpendicular relation with the recording surface, the first thin magnetic film having a first end, adjacent to the recording surface, which generates a magnetic flux perpendicular to the surface of the recording medium for recording information, and a second end; a second thin magnetic film having a first portion in substantially parallel relation with the first thin magnetic film and a second portion connected to the second end of the first thin magnetic film; and a magneto resistive element, in substantially parallel relation to the first thin magnetic film, for reproducing information; and a thin film coil, disposed in a plane which is substantially parallel to the first thin magnetic film and the first portion of the second thin magnetic film, the thin film coil having a center adjacent to the second end of the first thin magnetic film.
Claim 13
Dependent Claim
31 words
A perpendicular magnetic recording and reproducing head according to claim 10, wherein the thin film coil is a spiral coil and the first thin magnetic film is a main mono-magnetic pole.
Claim 14
Dependent Claim
45 words
A perpendicular magnetic recording and reproducing head according to claim 11, further comprising an insulating film formed between the spiral coil and the main pole, between the spiral coil and the second thin magnetic film and between the main pole and the magneto resistive element.
Claim 15
Dependent Claim
79 words
A perpendicular magnetic recording and reproducing head according to claim 11, wherein the second thin magnetic film has a third portion extending over and in substantially parallel relation to the main pole on the opposite side of the spiral coil from the main pole, the insulating film is formed between the spiral coil and the third portion of the second thin magnetic film and wherein the main pole and the second thin magnetic film form a closed flux structure.
Claim 16
Dependent Claim
48 words
A perpendicular magnetic recording and reproducing head according to claim 12, further comprising a third thin magnetic film in substantially parallel relation to the main pole and the magneto resistive element, wherein the insulating film is formed between the magnetic resistive element and the third thin magnetic film.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |