US4277809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for recording magnetic impulses perpendicular to the surface of a recording medium
Assignee: Memorex Corp
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Filing: 1979-09-26
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Granted: 1981-07-07
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Expires: 1999-09-26
Abstract
Abstract Apparatus is disclosed for recording magnetic impulses on a selectively magnetizable medium with such impulses being recorded with their axes of magnetization substantially perpendicular to the surface of the medium utilizing a recording medium having a high magnetic permeability backing layer and an overlying coating of magnetic material having uniaxial anisotropy substantially perpendicular to the surface of the backing layer, and using a unitary magnetic head for both recording and playback with such head positioned adjacent to one side of the recording medium.
Inventors
- 👤 Robert D. Fisher
- 👤 Eric R. Katz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B2005/0002; G11B2005/0026; G11B2005/0029; G11B5/127; G11B5/31; G11B5/48; G11B5/488; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/11; Y10T428/24; Y10T428/24942
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
In apparatus for recording magnetic impulses on a selectively magnetizable medium, which apparatus includes a recording medium, at least one magnetic recording and playback head, means for moving the recording medium relative to the recording head and means for supplying signals to the recording head for recording upon the medium, the improvement comprising said recording medium comprising an extended under layer of a material having a magnetic permeability greater than 100, with an overlying coating of magnetic material having uniaxial anisotropy substantially perpendicular to the surface of said under layer, and
Claim 2
Dependent Claim
91 words
In apparatus for recording magnetic impulses on a selectively magnetizable medium, which apparatus includes a recording medium, at least one magnetic recording and playback head, means for moving the recording medium relative to the recording head and means for supplying signals to the recording head for recording upon the medium, the improvement comprising said recording medium comprising an extended under layer of a material having a magnetic permeability greater than 100, with an overlying coating of magnetic material having uniaxial anisotropy substantially perpendicular to the surface of said under layer, and
Claim 3
Dependent Claim
120 words
said magnetic recording and playback head being a unitary recording/playback head having two closely spaced magnetic poles with both said poles positioned adjacent the outer surface of said recording medium overlying coating on one side of said medium, whereby the magnetic lines of flux extending between the poles of the head loop into and out of the outer surface of the recording medium overlying coating with the under layer of the recording medium causing the lines of flux to pass through the coating in a direction generally perpendicular to the surface of the medium to record information on the recording medium in the form of magnetic impulses having their axes of magnetization substantially perpendicular to the surface of the medium.
Claim 4
Dependent Claim
120 words
said magnetic recording and playback head being a unitary recording/playback head having two closely spaced magnetic poles with both said poles positioned adjacent the outer surface of said recording medium overlying coating on one side of said medium, whereby the magnetic lines of flux extending between the poles of the head loop into and out of the outer surface of the recording medium overlying coating with the under layer of the recording medium causing the lines of flux to pass through the coating in a direction generally perpendicular to the surface of the medium to record information on the recording medium in the form of magnetic impulses having their axes of magnetization substantially perpendicular to the surface of the medium.
Claim 5
Dependent Claim
65 words
The recording apparatus of claim 1 wherein said recording medium includes said magnetic coating overlying both opposed sides of said under layer, and wherein said apparatus includes at least one said magnetic recording/playback head positioned adjacent the outer surface of said recording medium coating on each side of said recording medium, whereby magnetic impulses may be recorded on both opposed sides of the recording medium.
Claim 6
Dependent Claim
38 words
The recording apparatus of claim 2 wherein said recording medium comprises an extended, substantially nonmagnetic substrate having said under layer overlying the two opposed sides of said substrate and said magnetic material coating overlying both said backing layers.
Claim 7
Dependent Claim
13 words
The recording apparatus of claim 3 wherein said substrate comprises an aluminum disc.
Claim 8
Dependent Claim
19 words
The recording apparatus of claim 1, 2, or 3 wherein said recording medium under layer comprises a ferromagnetic material.
Claim 9
Dependent Claim
20 words
The recording apparatus of claim 1, 2, or 3 wherein said recording medium backing under layer comprises a ferrimagnetic material.
Claim 10
Dependent Claim
16 words
The recording apparatus of claim 1, 2, or 3 wherein said backing layer comprises permalloy material.
Claim 11
Dependent Claim
15 words
The recording apparatus of claim 1 wherein said magnetic head comprises a ferrite air-gap head.
Claim 12
Dependent Claim
15 words
The recording apparatus of claim 1 wherein said magnetic head comprises a thin film head.
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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) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |