US3702377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for converting suppressed carrier chrominance signals into pal format
Assignee: Rank Organization Ltd
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Filing: 1970-09-18
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Granted: 1972-11-07
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Expires: 1990-09-18
Abstract
Abstract Suppressed carrier chrominance signal is translated to a desired frequency and in PAL form using a pilot signal at a sub-multiple of carrier frequency. Sum and difference signals are formed from a carrier frequency harmonic of the pilot and a wave at the desired frequency and appear alternately from line to line. These are combined with the chrominance signal to provide a desired PAL signal.
Inventors
- 👤 James A Kerr
- 👤 Bernhard J Rogers
- 👤 Leslie J Sutherland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:32
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/06; H04N11/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
102 words
A method of translating a suppressed carrier chrominance signal to a desired frequency and in PAL form using a pilot signal at a submultIple of the suppressed carrier, comprising the steps of obtaining a harmonic of the pilot signal at suppressed carrier frequency, deriving the sum and difference signals of said harmonic and a wave at said desired frequency so that the sum and difference signals appear alternately from line to line, and using said alternate sum and difference signals to translate the suppressed carrier signal into a color signal of PAL signal format having a carrier frequency of the desired frequency.
Claim 2
Independent Claim
102 words
A method of translating a suppressed carrier chrominance signal to a desired frequency and in PAL form using a pilot signal at a submultIple of the suppressed carrier, comprising the steps of obtaining a harmonic of the pilot signal at suppressed carrier frequency, deriving the sum and difference signals of said harmonic and a wave at said desired frequency so that the sum and difference signals appear alternately from line to line, and using said alternate sum and difference signals to translate the suppressed carrier signal into a color signal of PAL signal format having a carrier frequency of the desired frequency.
Claim 3
Dependent Claim
35 words
A method according to claim 1, wherein the deriving step comprises mixing said wave and said harmonic switching between the two resulting products using a pair of filters selected on a line by line basis.
Claim 4
Dependent Claim
108 words
Apparatus for translating a suppressed carrier chrominance signal to a desired frequency and in PAL form using a pilot signal at a submultiple of the suppressed carrier, comprising means for obtaining a harmonic of the pilot signal at suppressed carrier frequency, means for deriving the sum and difference of said harmonic and a wave at said desired frequency so that the sum and difference signals appear alternately from line to line, and means responsive to said alternate sum and difference signals and the suppressed carrier chrominance signal to translate the suppressed carrier signal into a color signal of PAL format having a carrier frequency of the desired frequency.
Claim 5
Dependent Claim
108 words
Apparatus for translating a suppressed carrier chrominance signal to a desired frequency and in PAL form using a pilot signal at a submultiple of the suppressed carrier, comprising means for obtaining a harmonic of the pilot signal at suppressed carrier frequency, means for deriving the sum and difference of said harmonic and a wave at said desired frequency so that the sum and difference signals appear alternately from line to line, and means responsive to said alternate sum and difference signals and the suppressed carrier chrominance signal to translate the suppressed carrier signal into a color signal of PAL format having a carrier frequency of the desired frequency.
Claim 6
Dependent Claim
60 words
Apparatus according to claim 3, wherein there is included in the means for deriving, means for mixing said harmonic and said wave, a pair of filters having passbands respectively centered on the respective frequencies of said sum and difference signals, and means for switching the products of said mixing between the pair of filters on a line by line basis.
Claim 7
Dependent Claim
23 words
Apparatus according to claim 3, comprising means for separating said suppressed carrier chrominance signal and the pilot signal from a composite input signal.
Claim 8
Dependent Claim
23 words
Apparatus according to claim 3, wherein there is included in the means for obtaining, a frequency multiplier for multiplying the pilot signal frequency.
References Cited (Backward Citations)
US2831917A
Cited
US3073894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |