US3576390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for generating test signals useful in measuring television transmission performance without affecting receiver synchronization
Assignee: RCA Corp
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Filing: 1968-05-29
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Granted: 1971-04-27
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Expires: 1988-05-29
Abstract
Abstract Apparatus for generating supervisory test signals in the interval between the beginning of vertical blanking and the beginning of vertical sync in a television synchronizing waveform, so as to free for other communication purposes those portions of the waveform such test signals conventionally occupy.
Inventors
- 👤 Donald S Bond
- 👤 Alfred C Schroeder
- 👤 Dalton H Pritchard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:31
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/08; H04N7/087; H04N17/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
204 words
In a television transmitting apparatus of the type in which test signals are generated and transmitted during each television field for measuring the performance of broadcast transmissions, the combination comprising: first means for generating a composite television synchronizing signal including a field scanning rate pulse having a leading edge in fixed time relation with respect to the beginning of the vertical blanking interval thereof on each odd and even television field; second means for respectively generating substantially identical test signals for each odd and even television field during which said test signals are transmitted; and third means coupled to said first and second means and responsive to the leading edge of said field scanning rate pulse on each television field for generating a gating signal substantially in time synchronism with the intervening interval between the beginning of said vertical blanking interval and the leading edge of said field scanning rate pulse on each television field and for repeatedly multiplexing said identical test signals with said composite signal during each of said intervening intervals in a manner to prevent the loss of synchronization at a television receiver, adjusted to receive said composite television signals, due to the addition of said test signals in said interval
Claim 2
Dependent Claim
204 words
In a television transmitting apparatus of the type in which test signals are generated and transmitted during each television field for measuring the performance of broadcast transmissions, the combination comprising: first means for generating a composite television synchronizing signal including a field scanning rate pulse having a leading edge in fixed time relation with respect to the beginning of the vertical blanking interval thereof on each odd and even television field; second means for respectively generating substantially identical test signals for each odd and even television field during which said test signals are transmitted; and third means coupled to said first and second means and responsive to the leading edge of said field scanning rate pulse on each television field for generating a gating signal substantially in time synchronism with the intervening interval between the beginning of said vertical blanking interval and the leading edge of said field scanning rate pulse on each television field and for repeatedly multiplexing said identical test signals with said composite signal during each of said intervening intervals in a manner to prevent the loss of synchronization at a television receiver, adjusted to receive said composite television signals, due to the addition of said test signals in said interval
Claim 3
Dependent Claim
58 words
The combination as defined in claim 1 wherein said second means generates substantially identical test signals on each television field, and wherein components of test signals capable of passing through a sync separator of a receiver adjusted to receive said composite signals have their modulation depth reduced to minimize their affect on the vertical synchronization of said receiver.
Claim 4
Dependent Claim
47 words
The combination as defined in claim 2 wherein said third means multiplexes said test signals with said composite signal in a manner to cause said test signals to precede the leading edge of said field scanning rate pulse by substantially the same amount on each television field.
Claim 5
Dependent Claim
42 words
The combination as defined in claim 3 wherein said third means multiplexes said test signals with said composite signal in a manner to position said test signals as far ahead of the leading edge of said field scanning rate pulse as possible.
Claim 6
Dependent Claim
64 words
The combination as defined in claim 3 wherein said second means generates test signals having frequency components of the order of the frequency components of said synchronizing signal and wherein said third means multiplexes said test signals with said composite signal in a manner to position said test signals as far ahead of the leading edge of said field scanning rate pulse as possible.
Claim 7
Dependent Claim
126 words
The combination as defined in claim 4 wherein said first means includes synchronizing generator means for supplying line and field scanning rate pulses, wherein said second means includes waveform generator means coupled to receive said line and field scanning rate pulses so as to be locked in phase to said synchronizing genErator means, and wherein said third means includes: a. mixing amplifier means arranged to receive said composite television synchronizing signal from said first means; and b. gated amplifier means responsive to the leading edge of said field scanning rate pulse for coupling said test signals from said second means to said mixing amplifier means during the interval between the beginning of said vertical blanking interval and the leading edge of said field scanning rate pulse.
References Cited (Backward Citations)
US3017457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |