US3909839A
Expired / Lapsed
US
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Phase locking system for television signals using digital memory techniques
Assignee: NEC Corp
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Filing: 1973-04-19
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Granted: 1975-09-30
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Expires: 1993-04-19
Abstract
Abstract An electronic system phase locks one or more input television signals to a signal of reference frequency and phase. The incoming signal is sampled at a first clock rate and phase, pulse code modulated, and stored in memory. The stored video information is then read out from memory under control of a second and independent clock which corresponds in its essential timing aspects to the reference signal.
Inventors
- 👤 Masao Inaba
- 👤 Kazuo Kashigi
- 👤 Satoshi Makara
- 👤 Harunobu Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:53
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/87; H04N9/877; H04N5/00; H04N5/04; H04N5/06; H04N5/067; H04N5/073; H04N5/0736; H04N5/12; H04N5/126; H04N9/89; H04N9/896
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
201 words
A phase locking system for a composite video signal, comprising: means for producing a first clock pulse wave having a predetermined phase relationship with said composite video signal; means for sampling and quantizing said composite video signal in timed relationship with said first clock pulse wave; a plurality of memory means for successively storing the output of said sampling and quantizing means in response to said first clock pulse wave, with at least one of said memory means being in a write-in state, and with others of said memory means being in an idle state suitable for information read-out; a plurality of buffer memories connected intermediate said respective memory means and said decoding means, and plural means for inhibiting said buffer memories from transferring output signals from said memory means while its respective memory means is in said write-in state; a source of a reference signal not synchronized with the incoming composite video signal; means for producing a second clock pulse wave having a predetermined phase relationship with said reference signal; and means for reading out the stored signal from said memory means disposed in said idle state in timed relationship with said second clock pulse wave through said buffer memories.
Claim 2
Dependent Claim
201 words
A phase locking system for a composite video signal, comprising: means for producing a first clock pulse wave having a predetermined phase relationship with said composite video signal; means for sampling and quantizing said composite video signal in timed relationship with said first clock pulse wave; a plurality of memory means for successively storing the output of said sampling and quantizing means in response to said first clock pulse wave, with at least one of said memory means being in a write-in state, and with others of said memory means being in an idle state suitable for information read-out; a plurality of buffer memories connected intermediate said respective memory means and said decoding means, and plural means for inhibiting said buffer memories from transferring output signals from said memory means while its respective memory means is in said write-in state; a source of a reference signal not synchronized with the incoming composite video signal; means for producing a second clock pulse wave having a predetermined phase relationship with said reference signal; and means for reading out the stored signal from said memory means disposed in said idle state in timed relationship with said second clock pulse wave through said buffer memories.
Claim 3
Dependent Claim
27 words
A combination as in claim 1 wherein said memory means includes means with capacity for storing quantized samples for one hoizontal line of said composite video signal.
Claim 4
Dependent Claim
26 words
A combination as in claim 1 wherein said memory means includes means with capacity for storing quantized samples for one field of said quantized video signal.
Claim 5
Dependent Claim
19 words
A combination in claim 1, further comprising comb filter means disposed inteRmediate said read-out means and said decoding means.
Claim 6
Dependent Claim
30 words
A combination as in claim 4 wherein said read out signal includes a subcarrier, further comprising subcarrier phase controller means connected to said decoding means and said reference signal source.
Claim 7
Dependent Claim
41 words
A combination as in claim 1 further comprising addressing means for allotting the quantized information from said sampling and quantizing means among said plural memories, and wherein said reading out means includes further addressing means for selectively interrogating said plural memories.
Claim 8
Dependent Claim
29 words
A combination as in claim 6 further comprising means responsive to said composite video signal for periodically resetting the state of said addressing means to a predetermined initial condition.
Claim 9
Dependent Claim
29 words
A combination as in claim 7 further comprising means responsive to said reference signal for periodically resetting the state of said further addressing means to a predetermined initial condition.
Claim 10
Dependent Claim
179 words
A phase locking system for a composite video signal, comprising: means for producing a first clock pulse wave having a predetermined phase relationship with said composite video signal; means for sampling and quantizing said composite video signal in timed relationship with said first clock pulse wave; means for storing the output of said sampling and quantizing means; a source of a reference signal; means for producing a second clock pulse wave having a preset phase relationship with said reference signal; means for reading out the stored signal in timed relationship with said second clock pulse wave; means for decoding the read out signal to produce said composite video signal wherein said read out signal includes luminance and carrier chrominance, and subcarrier signal components further comprising means for separating luminance and carrier chrominance signal components from said read out coded signal, said luminance and carrier chrominance signal components being supplied to said decoding means to produce analog luminance and carrier chrominance signals, respectively, and means for replacing the subcarrier contained in said analog carrier chrominance signal by the reference subcarrier.
Claim 11
Dependent Claim
179 words
A phase locking system for a composite video signal, comprising: means for producing a first clock pulse wave having a predetermined phase relationship with said composite video signal; means for sampling and quantizing said composite video signal in timed relationship with said first clock pulse wave; means for storing the output of said sampling and quantizing means; a source of a reference signal; means for producing a second clock pulse wave having a preset phase relationship with said reference signal; means for reading out the stored signal in timed relationship with said second clock pulse wave; means for decoding the read out signal to produce said composite video signal wherein said read out signal includes luminance and carrier chrominance, and subcarrier signal components further comprising means for separating luminance and carrier chrominance signal components from said read out coded signal, said luminance and carrier chrominance signal components being supplied to said decoding means to produce analog luminance and carrier chrominance signals, respectively, and means for replacing the subcarrier contained in said analog carrier chrominance signal by the reference subcarrier.
Claim 12
Dependent Claim
18 words
A phase locking system as claimed in claim 9, wherein said separating means is a digital comb filter.
References Cited (Backward Citations)
US3666880A
Cited
US3795763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |