US3702908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic tape driving system for tape recorders using a low frequency signal with a non-signal for reversing
Assignee: Sansui Electric Co Ltd
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Filing: 1970-08-25
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Granted: 1972-11-14
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Expires: 1990-08-25
Abstract
Abstract In an automatic tape driving system for a tape recorder utilizing a magnetic tape having first and second sound tracks which are used at the same time, a portion of the first sound track is recorded with a reverse signal of an inaudible low frequency, and a portion of the second sound track corresponding to the above described portion of the first sound track is not recorded with any signal. A logic circuit is connected to first and second signal channels associated with the first and second tracks to produce an output signal only when the first signal channel supplies thereto a signal corresponding to the reverse signal, and the second signal channel indicates the absence of a signal, to energize control means which reverses or stops the running of the magnetic tape.
Inventors
- 👤 Naokatsu Sugiura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:11
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/44; G11B15/442; G11B27/00; G11B27/10; G11B27/19; G11B27/22; G11B27/28; G11B27/30; G11B27/3018
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
176 words
In an automatic tape driving system for a tape recorder utilizing a magnetic tape having at least first and second sound tracks which are used at the same time, and having first and second signal channels corresponding to said first and second sound tracks, the improvement wherein: the first sound track has a given portion recorded with a reverse signal of an inaudible low frequency, and the second sound track has a given portion not recorded with any signal, said given portions of the first and second sound tracks occupying corresponding locations along the length of said magnetic tape and being simultaneously played back; and said driving system includes: a logic circuit coupled to said signal channels for generating an output only when said first signal channel supplies thereto a signal corresponding to said inaudible low frequency reverse signal recorded on said given portion of said first sound track and said second signal channel provides thereto no signal; and means responsive to the output from said logic circuit to control the movement of said magnetic tape.
Claim 2
Dependent Claim
176 words
In an automatic tape driving system for a tape recorder utilizing a magnetic tape having at least first and second sound tracks which are used at the same time, and having first and second signal channels corresponding to said first and second sound tracks, the improvement wherein: the first sound track has a given portion recorded with a reverse signal of an inaudible low frequency, and the second sound track has a given portion not recorded with any signal, said given portions of the first and second sound tracks occupying corresponding locations along the length of said magnetic tape and being simultaneously played back; and said driving system includes: a logic circuit coupled to said signal channels for generating an output only when said first signal channel supplies thereto a signal corresponding to said inaudible low frequency reverse signal recorded on said given portion of said first sound track and said second signal channel provides thereto no signal; and means responsive to the output from said logic circuit to control the movement of said magnetic tape.
Claim 3
Dependent Claim
41 words
The automatic tape driving system according to claim 1 wherein said first signal channel comprises a series circuit of a filter, an amplifier and a rectifier; and said second signal channel comprises A series circuit of an amplifier and a rectifier.
Claim 4
Dependent Claim
17 words
The automatic tape driving system according to claim 1 wherein said logic circuit comprises an inhibit circuit.
Claim 5
Dependent Claim
59 words
The automatic tape driving system according to claim 1 which further comprises an oscillator producing said reverse signal of inaudible low frequency, means to record said reverse signal on said given portion of said first track at one end of the magnetic tape and means to prevent recording of any signal on said given portion of said second track.
Claim 6
Dependent Claim
31 words
The automatic tape driving system according to claim 1 wherein said given portions of said first and second sound tracks are located at at least one end of said magnetic tape.
References Cited (Backward Citations)
US3461249A
Cited
US3573393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |