US3921203A
Expired / Lapsed
US
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Trisequential color video record-playback method and circuits
Assignee: BASF SE
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Filing: 1974-05-24
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Granted: 1975-11-18
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Expires: 1994-05-24
Abstract
Abstract A method and circuits for demodulating color video signals into trisequential form for recording and to recombine the trisequential signals into composite color video signals, using substantially the same method and circuit elements for both demodulation and recombination, where the demodulated trisequential signals have respectively the same phases as the phases of the received chrominance signals.
Inventors
- 👤 Bernard J Okey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:52
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/86
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
98 words
A method for demodulation of chrominance signals into trisequential form and for recombination of the trisequential signals comprising. a. generating a three phase color subcarrier having the three phases of the received chrominance signals; b. switching line sequentially the three phases of the subcarrier into an AM demodulator which produces three sequentially demodulated color difference signals; c. converting the three color difference signals into trisequential video signals, each consisting of one color signal and a luminance signal of high frequency during each line scan; and d. recombining the trisequential video signals into a video signal of standard format.
Claim 2
Independent Claim
98 words
A method for demodulation of chrominance signals into trisequential form and for recombination of the trisequential signals comprising. a. generating a three phase color subcarrier having the three phases of the received chrominance signals; b. switching line sequentially the three phases of the subcarrier into an AM demodulator which produces three sequentially demodulated color difference signals; c. converting the three color difference signals into trisequential video signals, each consisting of one color signal and a luminance signal of high frequency during each line scan; and d. recombining the trisequential video signals into a video signal of standard format.
Claim 3
Dependent Claim
19 words
A method as in claim 1, where the trisequential video signals are recombined into a standard PAL video signal.
Claim 4
Independent Claim
121 words
A method for recombination of trisequentially recorded signals comprising: a. separating the luminance portion of the recorded signal from the total trisequentially recorded signal which consists of a chrominance and luminance portion; b. generating a three phase color suBcarrier having the three phases of the recorded chrominance signals. c. switching line sequentially the three phases of the subcarrier into an AM modulator; d. combining, in the AM modulator, the three phases of the subcarrier with the chrominance signal; e. passing the combined signal from the AM modulator into a delay line which delays the combined sequential signals one or more line scan durations; f. composing the combined sequential signals and the luminance portion to produce a video signal of standard format.
Claim 5
Independent Claim
121 words
A method for recombination of trisequentially recorded signals comprising: a. separating the luminance portion of the recorded signal from the total trisequentially recorded signal which consists of a chrominance and luminance portion; b. generating a three phase color suBcarrier having the three phases of the recorded chrominance signals. c. switching line sequentially the three phases of the subcarrier into an AM modulator; d. combining, in the AM modulator, the three phases of the subcarrier with the chrominance signal; e. passing the combined signal from the AM modulator into a delay line which delays the combined sequential signals one or more line scan durations; f. composing the combined sequential signals and the luminance portion to produce a video signal of standard format.
Claim 6
Dependent Claim
26 words
A method as in claim 3, wherein step (f) comprises: composing the combined sequential signals and the luminance portion to produce a standard PAL video signal.
Claim 7
Independent Claim
119 words
A method for demodulation of chrominance signals in trisequential form comprising: a. generating a four phase color subcarrier, three phases of which are equal to the three phases of the received color signals, the fourth phase being a correction phase for correction of the phase difference between the phases of each color difference signal and the phases of each respective color signal; b. switching the three phases of the subcarrier into an AM demodulator which produces sequential demodulated color difference signals, the fourth phase subcarrier being continuously introduced into the demodulator; and c. converting the color difference signals into trisequential video signals each consisting of one color signal and a luminance signal of high frequency during each line scan.
Claim 8
Independent Claim
119 words
A method for demodulation of chrominance signals in trisequential form comprising: a. generating a four phase color subcarrier, three phases of which are equal to the three phases of the received color signals, the fourth phase being a correction phase for correction of the phase difference between the phases of each color difference signal and the phases of each respective color signal; b. switching the three phases of the subcarrier into an AM demodulator which produces sequential demodulated color difference signals, the fourth phase subcarrier being continuously introduced into the demodulator; and c. converting the color difference signals into trisequential video signals each consisting of one color signal and a luminance signal of high frequency during each line scan.
Claim 9
Dependent Claim
94 words
A circuit for demodulation of color video signals into a trisequential form comprising: a. a phase splitter for splitting an incoming standard color subcarrier frequency into at least a three phase color subcarrier having the three phases of the received color signals; b. an AM demodulator; c. means for switching the subcarriers from the phase splitter sequentially into an AM demodulator which produces sequential demodulated color difference signals; and d. means for converting the demodulated color difference signals into sequential signals consisting of one chrominance signal and a luminance signal during each line scan.
Claim 10
Dependent Claim
94 words
A circuit for demodulation of color video signals into a trisequential form comprising: a. a phase splitter for splitting an incoming standard color subcarrier frequency into at least a three phase color subcarrier having the three phases of the received color signals; b. an AM demodulator; c. means for switching the subcarriers from the phase splitter sequentially into an AM demodulator which produces sequential demodulated color difference signals; and d. means for converting the demodulated color difference signals into sequential signals consisting of one chrominance signal and a luminance signal during each line scan.
Claim 11
Dependent Claim
95 words
A circuit for modulation of trisequential video signals into color video signals comprising: a. a phase splitter for splitting an incoming standard color subcarrier frequency into at least a three phase color subcarrier having the three phases of the received color signals; b. an AM modulator; c. means for switching the subcarriers from the phase splitter line sequentially into the AM modulator which produces sequential AM modulated color signals; d. means for sequentially switching the AM modulated color signals; and e. means for converting said AM modulated color signals into of standard format video signals.
Claim 12
Dependent Claim
95 words
A circuit for modulation of trisequential video signals into color video signals comprising: a. a phase splitter for splitting an incoming standard color subcarrier frequency into at least a three phase color subcarrier having the three phases of the received color signals; b. an AM modulator; c. means for switching the subcarriers from the phase splitter line sequentially into the AM modulator which produces sequential AM modulated color signals; d. means for sequentially switching the AM modulated color signals; and e. means for converting said AM modulated color signals into of standard format video signals.
Claim 13
Dependent Claim
23 words
A circuit as in claim 7, wherein step (e) comprises means for converting said AM modulated color signals into standard PAL video signals.
Claim 14
Dependent Claim
145 words
A circuit for demodulation of chrominance signals into trisequential form and for remodulation to a standard broadcast video signal comprising: a. a phase splitter for splitting an incoming standard color subcarrrier frequency into at least a three phase color subcarrier having at least the three phases of the received color signals; b. an AM demodulator; c. an AM modulator; d. means for line sequential switching the subcarrier from the phase splitter into the AM demodulator in recording and into the AM modulator in playback; e. means for converting the demodulated color difference into trisequential video signals, each consisting of one chrominance signal and the luminance signal during each line scan; f. means for delaying the signals at least one line scan time; g. means for line sequentially switching the delayed signals; and h. means for converting the modulated color signals into standard broadcast video signals.
Claim 15
Dependent Claim
145 words
A circuit for demodulation of chrominance signals into trisequential form and for remodulation to a standard broadcast video signal comprising: a. a phase splitter for splitting an incoming standard color subcarrrier frequency into at least a three phase color subcarrier having at least the three phases of the received color signals; b. an AM demodulator; c. an AM modulator; d. means for line sequential switching the subcarrier from the phase splitter into the AM demodulator in recording and into the AM modulator in playback; e. means for converting the demodulated color difference into trisequential video signals, each consisting of one chrominance signal and the luminance signal during each line scan; f. means for delaying the signals at least one line scan time; g. means for line sequentially switching the delayed signals; and h. means for converting the modulated color signals into standard broadcast video signals.
Claim 16
Dependent Claim
22 words
A circuit as in claim 9, where the means for converting the Modulated color signals consists of a demodulator and a matrix.
References Cited (Backward Citations)
US3560635A
Cited
US3786178A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |