US4535369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording and reproducing apparatus
Assignee: Toshiba Corp
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Filing: 1983-11-16
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Granted: 1985-08-13
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Expires: 2003-11-16
Abstract
Abstract Signals are recorded on a magnetic tape having a magnetic recording layer containing a magnetic material whose high frequency characteristic varies with a magnetic field produced therein. Changes in the coupling degree of a high frequency coupling circuit caused by a signal field allows to reproduce a recorded signal.
Inventors
- 👤 Norikazu Sawazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:55
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278; G11B5/33; G11B5/332; G11B5/62
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
A magnetic recording and reproducing apparatus comprising: a magnetic material whose high frequency characteristic varies with a signal magnetic field from a magnetic recording medium; a high frequency coupling circuit whose coupling degree varies with said high frequency characteristic of the magnetic material; and means for reproducing a signal recorded on said magnetic recoding medium in accordance with the variation of the coupling degree of said high frequency coupling circuit.
Claim 2
Dependent Claim
70 words
A magnetic recording and reproducing apparatus comprising: a magnetic material whose high frequency characteristic varies with a signal magnetic field from a magnetic recording medium; a high frequency coupling circuit whose coupling degree varies with said high frequency characteristic of the magnetic material; and means for reproducing a signal recorded on said magnetic recoding medium in accordance with the variation of the coupling degree of said high frequency coupling circuit.
Claim 3
Dependent Claim
38 words
The magnetic recording and reproducing system according to claim 1, wherein said magnetic recording medium includes: a base layer; a magnetic layer formed on said base layer and containing a magnetic recording material magnetizable according to recording signals.
Claim 4
Dependent Claim
54 words
The magnetic recording and reproducing system according to claim 1, wherein said magnetic recording medium includes: a base layer; a magnetic recording layer formed on said base layer and magnetizable according to recording signals; and a magnetic layer formed between said base layer and said magnetic recording layer and consisting of said magnetic material.
Claim 5
Dependent Claim
29 words
The magnetic recording and reproducing system according to claim 1, wherein said high frequency coupling circuit includes means for supplying high frequency energy into said high frequency coupling circuit.
Claim 6
Dependent Claim
39 words
The magnetic recording and reproducing system according to claim 1, wherein the coupling degree of said high frequency coupling circuit varies according to ferromagnetic resonance absorption by the magnetic material whose high frequency characteristics vary with said magentic field.
Claim 7
Dependent Claim
121 words
The magnetic recording and reproducing system according to claim 5, wherein said high frequency coupling circuit includes a high frequency generator for generating a high frequency signal with a frequency causing the ferromagnetic resonance absorption to the magnetic material together with the signal magnetic field, first and second coils intersected with each other, the magnetic material being disposed at a position corresponding to the intersected portion of the first and second coils, the high frequency signal being supplied to the first coil, whereby said high frequency coupling circuit provides a low degree of electromagnetic coupling as an electric circuit in the absence of a signal and provides a high degree of electromagentic coupling with the ferromagnetic resonance of the magnetic material.
Claim 8
Dependent Claim
59 words
The magnetic recording and reproducing system according to claim 3, wherein said high frequency coupling circuit is provided in a reproducing head including: a stylus electrode having a top in contact with one side surface of said magentic recoding medium; and a conductor provided on the other side of said magnetic recording medium in opposition to said stylus electrode.
Claim 9
Dependent Claim
32 words
The magnetic recording and reproducing system according to claim 7, wherein said magnetic recording medium includes a conductive layer formed on the side of said medium in contact with said stylus electrode.
Claim 10
Dependent Claim
69 words
The magnetic recording and reproducing system according to claim 7, wherein said stylus electrode includes: an insulating stylus base; a magnetic film provided on one side of said insulating stylus base and having high frequency characteristics which are variable with a signal magnetic field; and a conductive film formed on the surface of said magnetic film other than a portion thereof corresponding to the top of said stylus electrode.
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) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |