US3849795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video tape recorder in which the drum is rotated synchronously with signals on tape
Assignee: Panasonic Holdings Corp
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Filing: 1973-05-31
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Granted: 1974-11-19
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Expires: 1993-05-31
Abstract
Abstract A video tape recorder has a cylindrical drum having at least one video head, a drum motor for rotating the video head, a capstan for moving the tape, a capstan motor for rotating the capstan, a detector for detecting the rotational speed of the video head, and a switch responsive to the detector so as to supply electric power to the capstan motor when the rotational speed of the video head exceeds a predetermined value.
Inventors
- 👤 M Koda
- 👤 T Shioyama
- 👤 A Nishiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:53
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/52
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
208 words
A video tape recorder comprising: a cylindrical drum having at least one rotatable video head for scanning a tape wrapped around said drum; a drum motor coupled to said drum for rotating said drum and video head; a capstan and a pressure roller for moving the tape in the longitudinal direction thereof in conjuction with each other; a capstan motor coupled to said capstan for rotating said capstan; detecting means coupled to said drum for detecting the rotational speed of said video head; and switch means coupled to said detecting means and said capstan motor and adapted to be coupled to a source of electric power for supplying power to said capstan motor, the detecting means controlling said switch means to the off condition during the time when said rotational speed of said video head is no higher than a predetermined speed, whereby no electric power for rotating said capstan motor is supplied through said switch means to said capstan motor, and the detecting means controlling the switch means to the off condition during the time when said rotational speed of said video head is higher than the predetermined speed, whereby electric power for rotating said capstan motor is supplied through said switch means to said capstan motor.
Claim 2
Dependent Claim
208 words
A video tape recorder comprising: a cylindrical drum having at least one rotatable video head for scanning a tape wrapped around said drum; a drum motor coupled to said drum for rotating said drum and video head; a capstan and a pressure roller for moving the tape in the longitudinal direction thereof in conjuction with each other; a capstan motor coupled to said capstan for rotating said capstan; detecting means coupled to said drum for detecting the rotational speed of said video head; and switch means coupled to said detecting means and said capstan motor and adapted to be coupled to a source of electric power for supplying power to said capstan motor, the detecting means controlling said switch means to the off condition during the time when said rotational speed of said video head is no higher than a predetermined speed, whereby no electric power for rotating said capstan motor is supplied through said switch means to said capstan motor, and the detecting means controlling the switch means to the off condition during the time when said rotational speed of said video head is higher than the predetermined speed, whereby electric power for rotating said capstan motor is supplied through said switch means to said capstan motor.
Claim 3
Dependent Claim
32 words
A video tape recorder as claimed in claim 1, wherein said detecting means is further coupled to said drum motor for supplying power for controlling the rotational speed of said drum motor.
Claim 4
Dependent Claim
45 words
A video tape recorder as claimed in claim 2, wherein said drum motor is a brushless DC motor directly coupled to said cylindrical drum, and said detecting means comprises generating windings which are positioned in the same slots as the main windings of said motor.
Claim 5
Dependent Claim
56 words
A video tape recorder as claimed in claim 1, wherein said switch means is an electrical switch circuit including a pair of transistors coupled to each other, one of said transistors functioning to supply electric power to said capstan motor upon actuation of the other transistor in response to an output signal from said detecting means.
Claim 6
Dependent Claim
39 words
A video tape recorder as claimed in claim 4, wherein said switch means further includes a variable resistor coupled to the base of said other transistor for regulating the voltage supplied to said other transistor from said detecting means.
References Cited (Backward Citations)
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US3390231A
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US3352977A
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Cited
US3651276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |