US4152733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Playback apparatus
Assignee: US Philips Corp
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Filing: 1977-07-15
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Granted: 1979-05-01
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Expires: 1997-07-15
Abstract
Abstract A playback apparatus for a recorded frequency modulated television signal includes a filter between the record carrier pick-up heads and the limiter-demodulator. The filter characteristics increase the ratio of the carrier signal frequency to the lower side band frequencies in response to a drop in carrier amplitude.
Inventors
- 👤 Harald Melwisch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:20
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/931; H04N5/9315
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
108 words
A playback apparatus for a record carrier on which a signal frequency-modulated on a carrier is recorded, said apparatus comprising a transducer means for scanning the record carrier and for providing an output signal consisting of a frequency modulated signal with a carrier and at least the lower side band, a limiter and demodulator means for demodulating the signal, and carrier signal controlled filter means connecting the transducer means to the limiter and demodulator means for increasing the amplitude of the carrier signal relative to the amplitudes of the signal components in the lower side band in response to a decrease in the amplitude of the carrier signal.
Claim 2
Dependent Claim
108 words
A playback apparatus for a record carrier on which a signal frequency-modulated on a carrier is recorded, said apparatus comprising a transducer means for scanning the record carrier and for providing an output signal consisting of a frequency modulated signal with a carrier and at least the lower side band, a limiter and demodulator means for demodulating the signal, and carrier signal controlled filter means connecting the transducer means to the limiter and demodulator means for increasing the amplitude of the carrier signal relative to the amplitudes of the signal components in the lower side band in response to a decrease in the amplitude of the carrier signal.
Claim 3
Dependent Claim
64 words
An apparatus as claimed in claim 1, wherein the filter means is a highpass filter comprising half a T-network, of which one branch includes an ohmic resistance and whose other branch comprises a reactive impedance, and at least one circuit element whose impedance decreases as a function of the amplitude of the carrier signal appearing across it connected in parallel with said reactive impedance.
Claim 4
Dependent Claim
44 words
An apparatus as claimed in claim 1, wherein said filter means is a low-pass filter comprising a multi-element tuned circuit, and an impedance that decreases in response to increasing carrier signal amplitude connected in parallel with at least one element of said tuned circuit.
Claim 5
Dependent Claim
85 words
An apparatus as claimed in claim 1, wherein the filter means comprises a first channel means for passing said carrier signal, a further channel means for delaying the carrier signals passing therethrough with respect to the signals passing through said first channel means, means for combining the output signals of the first and the further channels, and a circuit element in one of said channels having an impedance that is variable depending on the amplitude of the carrier signal in said one of said channels.
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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) | 1982-04-30 | 1982-10-30 | 1983-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-30 | 1986-10-30 | 1987-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-30 | 1990-10-30 | 1991-05-01 | $7700.00 | Window Closed / Lapsed |