Patent US3869706A successfully refreshed from Google Patents.
US3869706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for converting television signals into angle modulated carrier waveforms of reduced bandwidth and vice-versa
Assignee: Thales SA
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Filing: 1973-06-07
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Granted: 1975-03-04
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Expires: 1993-06-07
Abstract
Abstract The invention relates to systems for converting television signals into angle modulated waveforms of reduced bandwidth. The conversion consists in splitting the video information into two complementary portions which are distinct frequency bands. The portions are alternatively fed to the modulating input of an angle modulator at a switching rate equal to the line scanning of the television raster. Thus, an interleaved time multiplexed sequence of slices is angle modulated. The reverse operation is performed with two angle demodulating channels, one of which is provided for delaying the incoming waveform by the duration of scanning of a line; the restored video information comprises slices of video information alternately picked up at the outputs of said channels.
Inventors
- 👤 Jean Paul Peltier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:51
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/917; H04N5/92; H04N5/9201; H04N5/9202; H04N5/9204; H04N7/00; H04N7/12; H04N7/127; H04N9/00; H04N9/79; H04N9/80; H04N9/86
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
197 words
A method for converting television signals into multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said method comprising the steps of: splitting said television signals into first and second distinct frequency bands respectively alloted to the transmission of first and second television signal components carrying together the videofrequency information pertaining to said television signals, partitioning each of said first and second television signal componEnts into slices in accordance with a sequence of time intervals substantially equal to the line scanning duration of said television signals, selecting without delay half of said slices for forming a time multiplexed sequence of slices wherein a slice of said first television signal component corresponding to a predetermined line in one field is immediately followed by a slice of said second television signal component corresponding to the next line in said field, and angle modulating a carrier waveform with said time multiplexed sequence of slices; said method, for simultaneously processing the audio frequency information associated with the television image, further comprising the step of continuously modulating said carrier waveform with a further modulated subcarrier waveform carrying said audio-frequency information and the line synchronization signals of said video-frequency information.
Claim 2
Independent Claim
197 words
A method for converting television signals into multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said method comprising the steps of: splitting said television signals into first and second distinct frequency bands respectively alloted to the transmission of first and second television signal components carrying together the videofrequency information pertaining to said television signals, partitioning each of said first and second television signal componEnts into slices in accordance with a sequence of time intervals substantially equal to the line scanning duration of said television signals, selecting without delay half of said slices for forming a time multiplexed sequence of slices wherein a slice of said first television signal component corresponding to a predetermined line in one field is immediately followed by a slice of said second television signal component corresponding to the next line in said field, and angle modulating a carrier waveform with said time multiplexed sequence of slices; said method, for simultaneously processing the audio frequency information associated with the television image, further comprising the step of continuously modulating said carrier waveform with a further modulated subcarrier waveform carrying said audio-frequency information and the line synchronization signals of said video-frequency information.
Claim 3
Dependent Claim
38 words
A method as claimed in claim 1, wherein for converting monochrome television signals, the frequency band of said video-frequency information is split into two adjacent ranges respectively containing the spectra of said first and second television signal components.
Claim 4
Dependent Claim
16 words
A method as claimed in claim 2, wherein said adjacent ranges have substantially the same bandwidth.
Claim 5
Dependent Claim
38 words
A method as claimed in claim 1, wherein for converting colour television signals, said first and second television signal components are respectively constituted by a luminance signal, and by a composite signal including two frequency multiplexed chrominance signals.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 4, wherein said composite signal being obtained by mixing with one another two sub-carrier waveforms respectively modulated by said chrominance signals.
Claim 7
Dependent Claim
63 words
A method as claimed in claim 1, wherein the television signals being constituted by two interlaced fields, said multiplexed signals contain a slice of said first television signal component corresponding to a given line in one of said interlaced fields and another slice pertaining to said second television signal component, and corresponding to the next line in the other of said interlaced fields.
Claim 8
Independent Claim
178 words
A method for restoring television signals from multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said carrier waveform being modulated by a time multiplexed sequence of slices, said slices having a duration equal to the line scanning time of said television signals, and being respectively made of first and second television signal components carrying together the video information ; said carrier waveform being further modulated by a line synchronization signal ; said method comprising the following steps : feeding said multiplexed signals simultaneously to first and second angle demodulating channels, introducing in one of said channels a signal delay substantially equal to said line scanning time, separating from one another said first and second television signal components at the respective outputs of said first and second angle demodulating channels, alternately transmitting said separated first and second television signal components to a summing network, and selectively transmitting said line synchronization signal taken from one of said outputs for controlling the alternate transmission to said summing network of said separated first and second television signal components.
Claim 9
Independent Claim
178 words
A method for restoring television signals from multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said carrier waveform being modulated by a time multiplexed sequence of slices, said slices having a duration equal to the line scanning time of said television signals, and being respectively made of first and second television signal components carrying together the video information ; said carrier waveform being further modulated by a line synchronization signal ; said method comprising the following steps : feeding said multiplexed signals simultaneously to first and second angle demodulating channels, introducing in one of said channels a signal delay substantially equal to said line scanning time, separating from one another said first and second television signal components at the respective outputs of said first and second angle demodulating channels, alternately transmitting said separated first and second television signal components to a summing network, and selectively transmitting said line synchronization signal taken from one of said outputs for controlling the alternate transmission to said summing network of said separated first and second television signal components.
Claim 10
Dependent Claim
36 words
A method as claimed in claim 7, wherein the separation from one another of said first and second television signal components is performed by filtering the demodulated carrier waveform in each of said angle demodulating channels.
Claim 11
Dependent Claim
34 words
A method as claimed in claim 7, wherein the control of said alternate transmission is performed by selectively picking up the line synchronization signal at the output of one of said angle demodulating channels.
Claim 12
Dependent Claim
41 words
A method as claimed in claim 7, wherein an audio-frequency information associated with said video-information is extracted from said multiplexed signal by demodulating at the oUtput of one of said angle demodulating channels, a sub-carrier wave modulated by said audio-frequency information.
Claim 13
Dependent Claim
42 words
A method as claimed in claim 7, wherein for colour multiplex signals embodying two chrominance signals, extraction is carried out by demodulating at the output of one of said angle demodulating channels two sub-carrier waveforms respectively modulated by said two chrominance signals.
Claim 14
Independent Claim
205 words
A system for converting television signals into multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said system comprising: means for splitting said television signals into first and second distinct frequency bands respectively alloted to the transmission of first and second television signal components carrying together the video-frequency information pertaining to said television signals ; switching means alternately transmitting without delay slices of said first and second television signal components for forming a time multiplexed sequence of slices having each a duration equal to the line scanning time of said television signals ; means for angle modulating said carrier waveform with said time multiplexed sequence of slices, and means for further modulating said carrier waveform with a subcarrier waveform modulated by the line synchronization signal of said television signals ; a predetermined slice of said time multiplexed sequence belonging to one of said first and second television signal components and the next slice of said sequence belonging to the other of said first and second television signal components; said system further comprising sub-carrier waveform modulating means having an input for receiving an audio-frequency signal associated with said video-frequency information, and an output feeding the modulating input of said carrier angle modulating means.
Claim 15
Independent Claim
205 words
A system for converting television signals into multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said system comprising: means for splitting said television signals into first and second distinct frequency bands respectively alloted to the transmission of first and second television signal components carrying together the video-frequency information pertaining to said television signals ; switching means alternately transmitting without delay slices of said first and second television signal components for forming a time multiplexed sequence of slices having each a duration equal to the line scanning time of said television signals ; means for angle modulating said carrier waveform with said time multiplexed sequence of slices, and means for further modulating said carrier waveform with a subcarrier waveform modulated by the line synchronization signal of said television signals ; a predetermined slice of said time multiplexed sequence belonging to one of said first and second television signal components and the next slice of said sequence belonging to the other of said first and second television signal components; said system further comprising sub-carrier waveform modulating means having an input for receiving an audio-frequency signal associated with said video-frequency information, and an output feeding the modulating input of said carrier angle modulating means.
Claim 16
Dependent Claim
36 words
A system as claimed in claim 12, wherein for processing monochrome video-frequency information, said splitting means comprise a low pass and a high pass filter; the pass bands of said filters being adjacent with one another.
Claim 17
Dependent Claim
45 words
A system as claimed in claim 12, wherein for processing colour video-frequency information, said splitting means comprise a filter transmitting the luminance component of said colour video-frequency information, and a pair of sub-carrier modulating means respectively receiving two chrominance components of said colour video-frequency information.
Claim 18
Independent Claim
167 words
A system for restoring television signals from multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said carrier waveform being modulated by a time multiplexed sequence of slices, said slices having a duration equal to the line scanning time of said television signals, and being respectively made of first and second television signal components carrying together the video-frequency information pertaining to said television signals ; said carrier waveform further carrying a line synchronization signal ; said system comprising : first and second angle demodulating channels simultaneously receiving said multiplexed signals, identical frequency demultiplexing means connected at the respective outputs of said first and second angle demodulating channels for selectively transmitting said first and second television signal components, switching means respectively connected at the outputs of said frequency demultiplexing means, summing means fed from said switching means and selective transmission means connected to one output of said angle demodualting channels for controlling the operation of said switching means in accordance with said line synchronization signals.
Claim 19
Independent Claim
167 words
A system for restoring television signals from multiplexed signals constituted by an angle modulated carrier waveform of reduced bandwidth, said carrier waveform being modulated by a time multiplexed sequence of slices, said slices having a duration equal to the line scanning time of said television signals, and being respectively made of first and second television signal components carrying together the video-frequency information pertaining to said television signals ; said carrier waveform further carrying a line synchronization signal ; said system comprising : first and second angle demodulating channels simultaneously receiving said multiplexed signals, identical frequency demultiplexing means connected at the respective outputs of said first and second angle demodulating channels for selectively transmitting said first and second television signal components, switching means respectively connected at the outputs of said frequency demultiplexing means, summing means fed from said switching means and selective transmission means connected to one output of said angle demodualting channels for controlling the operation of said switching means in accordance with said line synchronization signals.
Claim 20
Dependent Claim
42 words
A system as claimed in claim 15, further comprising means for selectively demodulating a sub-carrier waveform modulated by an audiofrequency information associated with said video-information ; said further demodulating means being connected at the output of one of said angle demodulating channels.
Claim 21
Dependent Claim
30 words
A system as claimed in claim 15, wherein for restoring monochrome telEvision signals, said frequency demultiplexing means comprise two identical sets of low-pass and high-pass filters having adjacent pass bands.
Claim 22
Dependent Claim
42 words
A system as claimed in claim 15, wherein for restoring colour television signals, said frequency demultiplexing means comprise two identical sets ; each of said sets including a low-pass filter and two sub-carrier waveform demodulator circuits respectively operating in adjacent frequency bands.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |