US3833920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video transducing electric circuits
Assignee: IIT Research Institute
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Filing: 1973-04-19
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Granted: 1974-09-03
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Expires: 1993-04-19
Abstract
Abstract Monochrome and color television recording and playback circuitry for coupling of a video magnetic transducer head with a standard broadcast television receiver, the circuitry including a coupling capacitor and means for supplying electric charge to one terminal of the capaictor, a record-playback switch connected between the other terminal of the capacitor and one terminal of the head winding, and a resistor for maintaining the other terminal of the capacitor substantially at ground potential while the switch is in playback position to prevent surges of current through the head winding during switching.
Inventors
- 👤 M Camras
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:11
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/765; H04N5/775
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
298 words
A transducer system comprising: a magnetic head having a magnetic core for coupling to a magnetic record medium and having an electric winding (6-24) inductively coupled to the magnetic core, said electric winding (6-24) during recording having one terminal thereof connected to a circuit point having a predetermined direct current potential, a circuit including a coupling capacitor (6-C27) and means for supplying electric charge to one terminal of said capacitor (6C27) and an electric switch connected between the other terminal of the capacitor (6-C27) and the other terminal of the electric winding (6-24), and resistance means (6-R36) having one terminal coupled via a direct current path to said circuit between said other terminal of said capacitor (6-C27) and said switch, and having its other terminal connected via a direct current path to said circuit point having said predetermined direct current potential, the switch in its record position during recording operation connecting the other terminal of said capacitor (6-C27) with said electric winding (6-24), and in its playback position during playback operation being open to open circuit any path for signal current from said capacitor (6-C27) to said electric winding (6-24), said resistance means (6-R36) being permanently coupled to said other terminal of said capacitor (6-C27) to continuously provide a direct current path to said circuit point of said predetermined direct current potential for maintaining said other terminal of said capacitor (6-C27) at substantially the same direct current potential as said electric winding (6-24) both while said switch is open and during switching from its recording position to its playback position, and from its playback position to its recording position, said resistance means (6-R36) providing the only direct current path from said other terminal of said capacitor (6-C27) to said circuit point in the playback position of said switch.
Claim 2
Dependent Claim
298 words
A transducer system comprising: a magnetic head having a magnetic core for coupling to a magnetic record medium and having an electric winding (6-24) inductively coupled to the magnetic core, said electric winding (6-24) during recording having one terminal thereof connected to a circuit point having a predetermined direct current potential, a circuit including a coupling capacitor (6-C27) and means for supplying electric charge to one terminal of said capacitor (6C27) and an electric switch connected between the other terminal of the capacitor (6-C27) and the other terminal of the electric winding (6-24), and resistance means (6-R36) having one terminal coupled via a direct current path to said circuit between said other terminal of said capacitor (6-C27) and said switch, and having its other terminal connected via a direct current path to said circuit point having said predetermined direct current potential, the switch in its record position during recording operation connecting the other terminal of said capacitor (6-C27) with said electric winding (6-24), and in its playback position during playback operation being open to open circuit any path for signal current from said capacitor (6-C27) to said electric winding (6-24), said resistance means (6-R36) being permanently coupled to said other terminal of said capacitor (6-C27) to continuously provide a direct current path to said circuit point of said predetermined direct current potential for maintaining said other terminal of said capacitor (6-C27) at substantially the same direct current potential as said electric winding (6-24) both while said switch is open and during switching from its recording position to its playback position, and from its playback position to its recording position, said resistance means (6-R36) providing the only direct current path from said other terminal of said capacitor (6-C27) to said circuit point in the playback position of said switch.
References Cited (Backward Citations)
US3160824A
Cited
US3316360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |