Patent US4464691A successfully refreshed from Google Patents.
US4464691A
Expired / Lapsed
US
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Magnetic reproducing system
Assignee: Toshiba Corp
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Filing: 1981-08-05
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Granted: 1984-08-07
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Expires: 2001-08-05
Abstract
Abstract A magnetic head includes a magnetic body, at least the permeability or high frequency loss of which is changed with changes of the record magnetic field on a magnetic tape, and a coil. A high frequency signal is supplied to a tuned circuit, which includes the coil and a capacitor, and a signal corresponding to the record magnetic field is taken out through the detection of the changes of the voltage of the high frequency signal supplied to the tuned circuit.
Inventors
- 👤 Norikazu Sawazaki
- 👤 Shu Chiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/332
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
192 words
A magnetic reproducing system comprising: a magnetic head having a magnetic body buried in a molding which serves as a head base, in such a way that it is partly exposed and is in frictional contact with a magnetic recording medium, and a strip coil buried in said molding in such a way that it is electromagnetically coupled with said magnetic body, and the edge of said strip coil on one side thereof is in the vicinity of said magnetic body; and means for obtaining a reproduced signal across said strip coil according to changes in a record magnetic field of said magnetic recording medium, wherein said reproduced signal obtaining means has a tuned circuit including said strip coil, a pair of conductive film divisions provided on said head base and connected to opposite ends of said strip coil, and a tuning capacitor connected between said pair of conductive film divisions, means for supplying a high frequency signal to the tuned circuit and means for deriving a signal corresponding to said record magnetic field through the detection of changes in the voltage of the high frequency signal supplied to said tuned circuit.
Claim 2
Dependent Claim
192 words
A magnetic reproducing system comprising: a magnetic head having a magnetic body buried in a molding which serves as a head base, in such a way that it is partly exposed and is in frictional contact with a magnetic recording medium, and a strip coil buried in said molding in such a way that it is electromagnetically coupled with said magnetic body, and the edge of said strip coil on one side thereof is in the vicinity of said magnetic body; and means for obtaining a reproduced signal across said strip coil according to changes in a record magnetic field of said magnetic recording medium, wherein said reproduced signal obtaining means has a tuned circuit including said strip coil, a pair of conductive film divisions provided on said head base and connected to opposite ends of said strip coil, and a tuning capacitor connected between said pair of conductive film divisions, means for supplying a high frequency signal to the tuned circuit and means for deriving a signal corresponding to said record magnetic field through the detection of changes in the voltage of the high frequency signal supplied to said tuned circuit.
Claim 3
Dependent Claim
31 words
The magnetic reproducing system according to claim 1, wherein said strip coil is a U-shaped strip coil buried in said molding in such a way that it surrounds said magnetic body.
Claim 4
Dependent Claim
31 words
The reproducing system according to claim 1 or 2 wherein bias magnetic field generating means is burried in said molding at a position thereof in the vicinity of said magnetic body.
Claim 5
Dependent Claim
62 words
The reproducing system according to claim 1 or 2, wherein said magnetic body is made of a magnetic material, the permeability of which changes greatly with changes in the record magnetic field, and changes in the voltage of said high frequency signal resulting from changes in the tuning frequency of the tuned circuit, due to changes of the permeability, may be detected.
Claim 6
Dependent Claim
68 words
The reproducing system according to claim 1 or 2, wherein said magnetic body is made of a magnetic material, the high frequency loss in which is greatly changed with changes in the record magnetic field, and changes in the voltage of said high frequency signal resulting from changes in the quality Q of the tuned circuit, due to the changes of the high frequency loss, may be detected.
Claim 7
Dependent Claim
157 words
A magnetic reproducing system comprising: a magnetic head having a magnetic body with a coil wound thereon; and means for obtaining a reproduced signal across said coil according to changes in the record magnetic field of said magnetic recording medium, wherein said means for obtaining a reproduced signal having a tuned circuit including said coil, means for supplying the high frequency signal to the tuned circuit and means for deriving a signal corresponding to said record magnetic field through the detection of the changes in the voltage of the high frequency signal supplied to said tuned circuit; and wherein said magnetic body is made of a magnetic material, the high frequency loss of which is greatly changed with changes in the record magnetic field, and changes in the voltage of said high frequency signal resulting from changes in the quality Q of the tuned circuit, due to the changes of the high frequency loss, may be detected.
Claim 8
Dependent Claim
157 words
A magnetic reproducing system comprising: a magnetic head having a magnetic body with a coil wound thereon; and means for obtaining a reproduced signal across said coil according to changes in the record magnetic field of said magnetic recording medium, wherein said means for obtaining a reproduced signal having a tuned circuit including said coil, means for supplying the high frequency signal to the tuned circuit and means for deriving a signal corresponding to said record magnetic field through the detection of the changes in the voltage of the high frequency signal supplied to said tuned circuit; and wherein said magnetic body is made of a magnetic material, the high frequency loss of which is greatly changed with changes in the record magnetic field, and changes in the voltage of said high frequency signal resulting from changes in the quality Q of the tuned circuit, due to the changes of the high frequency loss, may be detected.
Claim 9
Dependent Claim
24 words
The reproducing system according to claim 6, wherein said magnetic body is provided in the magnetic path of a magnetic core having a gap.
Claim 10
Dependent Claim
46 words
The reproducing system according to claim 7, wherein the coil wound on said magnetic body is arranged in such a way that the high frequency magnetic field generated from the coil and the magnetic field generated from the record magnetic field are perpendicular to each other.
Claim 11
Dependent Claim
47 words
The reproducing system according to claim 7, wherein a pair of permanent magnets for biasing are provided in said magnetic path on opposite sides of said magnetic body, the magnetic field from said permanent magnets from biasing being perpendicular to the magnetic field from the recording medium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-07 | 1988-02-06 | 1988-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-07 | 1992-02-06 | 1992-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-07 | 1996-02-06 | 1996-08-07 | $7700.00 | Window Closed / Lapsed |