US3580992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-head magnetic recording and reproducing device for video signals featuring head switching in the record mode
Assignee: Sony Corp
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Filing: 1968-06-18
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Granted: 1971-05-25
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Expires: 1988-06-18
Abstract
Abstract In a magnetic recording and reproducing device having two rotary magnetic heads for recording and reproducing signals, such as video signals, in skew tracks traced across a magnetic tape by the heads, a switching circuit is provided which, during recording, alternately supplies the video signals to the heads in synchronism with the vertical synchronizing pulses included in the video signals. The video signals thus recorded in successive tracks have overlapping portions which either correspond to a very short recording period of the order of one horizontal period of the video signal and are contained in the vertical blanking period of the signal, or one of such overlapping portions is recorded at a substantially lower level than the other. In reproducing the video signals thus recorded, the outputs of the heads are merely combined.
Inventors
- 👤 Yasuhito Eguchi
- 👤 Yoshio Fujiwara
- 👤 Takaaki Tohma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:02
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/02; G11B15/12; G11B15/14; H; H04; H04N; H04N5/00; H04N5/76; H04N5/91
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
227 words
A device for magnetically recording and reproducing video signals on a magnetic tape, which video signals include vertical synchronizing signals, said device comprising a plurality of rotary magnetic heads, means to rotate said heads in synchronism with said vertical synchronizing signals, means guiding the magnetic tape in a path at which the tape is alternately contacted by said heads along skew tracks successively traced by the heads on said tape, means operative during recording operation of the device for supplying the video signals to said heads for recording of all of the video signals by the heads in the respective skew tracks successively traced thereby and including switching means having a plurality of states corresponding in number to the number of said heads and in each of which said video signals are supplied to a respective one of said heads, switching control means operated by said vertical synchronizing signals of the video signals during said recording operation of the device and successively alternating said states of said switching means to cause successive portions of said video signals to be recorded in the tracks traced by the respective heads, and means operative during the reproducing operation of said device to continuously combine the entire outputs of said heads and thereby provide a combined output constituted by the successive portions of said video signals reproduced alternately by said heads.
Claim 2
Independent Claim
227 words
A device for magnetically recording and reproducing video signals on a magnetic tape, which video signals include vertical synchronizing signals, said device comprising a plurality of rotary magnetic heads, means to rotate said heads in synchronism with said vertical synchronizing signals, means guiding the magnetic tape in a path at which the tape is alternately contacted by said heads along skew tracks successively traced by the heads on said tape, means operative during recording operation of the device for supplying the video signals to said heads for recording of all of the video signals by the heads in the respective skew tracks successively traced thereby and including switching means having a plurality of states corresponding in number to the number of said heads and in each of which said video signals are supplied to a respective one of said heads, switching control means operated by said vertical synchronizing signals of the video signals during said recording operation of the device and successively alternating said states of said switching means to cause successive portions of said video signals to be recorded in the tracks traced by the respective heads, and means operative during the reproducing operation of said device to continuously combine the entire outputs of said heads and thereby provide a combined output constituted by the successive portions of said video signals reproduced alternately by said heads.
Claim 3
Dependent Claim
49 words
A device according to claim 1, in which said switching control means includes means to gradually terminate each of said states of said switching means so that the supplying of said video signals to each of said heads is gradually interrupted by the gradual termination of the respective state.
Claim 4
Dependent Claim
81 words
A device according to claim 1, in which there are two of said heads, and said switching control means is operated by said vertical synchronizing signals to cause odd number fields of said video signals to be recorded by one of said heads in said skew tracks traced thereby and even number fields to be recorded by the other of said heads in the skew tracks that are traced by said other head intermediate said tracks traced by said one head.
Claim 5
Dependent Claim
82 words
A device according to claim 3, in which said heads are angularly spaced from each other so as to simultaneously contact the tape when tracing the beginning and end parts of respective adjacent tracks, and said switching control means includes means by which said states of the switching means are alternated in overlapping relation with each period of overlap being of the order of the horizontal period of said video signal and occurring during a vertical blanking period of said video signals.
Claim 6
Dependent Claim
129 words
A device according to claim 1, in which said heads are angularly spaced from each other so as to simultaneously contact the tape when tracing the beginning and end parts of respective adjacent tracks, said switching control means includes means by which said states of the switching means are alternated with time intervals between the successive states, and said switching means includes means operative in only one of said states to supply the video signals at a predetermined level to one of said heads and means operative in another of said states to supply the video signals at substantially said predetermined level to another of said heads and being otherwise operative to supply the video signals to said other head at a level substantially lower than said predetermined level.
Claim 7
Dependent Claim
36 words
A device according to claim 5, in which said switching control means includes means by which said time intervals between the successive alternated states are made to occur in vertical blanking periods of the video signals.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |