Patent US3600523A successfully refreshed from Google Patents.
US3600523A
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Reproduction process for magnetic tapes
Assignee: Telefunken Patentverwertungs GmbH
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Filing: 1968-09-30
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Granted: 1971-08-17
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Expires: 1988-09-30
Abstract
Abstract A contact reproduction process for magnetic tape recordings wherein information is first recorded on a tape, which forms the original, in the form of at least one strand of magnetizable material having cross-sectional variations provided therein. The original tape is then brought into contact with a blank tape and, subsequently, both tapes are exposed to a direct-current field and a high frequency field superimposed thereon. Since the original tape cannot be erased, it can be exposed to an optimum field intensity.
Inventors
- 👤 Eduard Schuller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/86; G11B5/865
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
Process for reproducing magnetic tapes comprising the steps of: a. recording information on a tape in the form of at least one strand of magnetizable material having cross-sectional variations which represent information provided therein, said tape forming the original tape; b. contacting said original tape with a blank tape; and c. simultaneously exposing said contacted tapes to a directcurrent field having a high frequency field superimposed thereon as said tapes are moved relative to said superimposed fields, whereby the information recorded on said original tape is reproduced on said blank tape.
Claim 2
Dependent Claim
91 words
Process for reproducing magnetic tapes comprising the steps of: a. recording information on a tape in the form of at least one strand of magnetizable material having cross-sectional variations which represent information provided therein, said tape forming the original tape; b. contacting said original tape with a blank tape; and c. simultaneously exposing said contacted tapes to a directcurrent field having a high frequency field superimposed thereon as said tapes are moved relative to said superimposed fields, whereby the information recorded on said original tape is reproduced on said blank tape.
Claim 3
Dependent Claim
33 words
The process defined in claim 1 wherein said original and said blank tape are continuously moved through said superimposed direct current and high frequency fields in a direction perpendicular to the superimposed fields.
Claim 4
Dependent Claim
29 words
Process as defined in claim 1 wherein said step (a) is accomplished, at least in part, by cutting a groove into said tape with a mechanical depth recording means.
Claim 5
Dependent Claim
22 words
Process as defined in claim 3 wherein the cross-sectional area variations of said groove are transverse to the length of the tape.
Claim 6
Dependent Claim
28 words
Process as defined in claim 3 wherein said mechanical depth recording means is a cutting stylus having an angle between its cutting sides which is greater than 90*.
Claim 7
Dependent Claim
28 words
Process as defined in claim 5 wherein said stylus cuts a groove into a nonmagnetic tape and said strand is produced by filling the groove with magnetic material.
Claim 8
Dependent Claim
19 words
A process as defined in claim 6 wherein more than one of said strands is provided on said tape.
Claim 9
Dependent Claim
31 words
Process as defined in claim 5 wherein said stylus cuts a groove in a nonmagnetic tape and said strand is produced by filling the groove with synthetic material and magnetic powder.
Claim 10
Dependent Claim
19 words
A process as defined in claim 8 wherein more than one of said strands is provided on said tape.
Claim 11
Dependent Claim
35 words
A process as defined in claim 5 wherein said stylus cuts a groove in a nonmagnetic tape and said strand is produced by galvanically applying an iron layer to the top surface of saiD groove.
Claim 12
Dependent Claim
19 words
A process as defined in claim 10 wherein more than one of said strands is provided on said tape.
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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) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |