Patent US3838444A successfully refreshed from Google Patents.
US3838444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for transmitting auxiliary information in low energy density portion of color tv spectrum
Assignee: Hazeltine Research Inc
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Filing: 1972-10-30
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Granted: 1974-09-24
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Expires: 1992-10-30
Abstract
Abstract DESCRIBED IS A SYSTEM FOR COMPATIBLY TRANSMITTING AND RECEIVING BOTH A COLOR TV SIGNAL AND AN ADD-ON SIGNAL WITHIN THE FREQUENCY BAND NORMALLY OCCUPIED BY THE TV SIGNAL ALONE. THIS SYSTEM UTILIZES A HIGH FREQUENCY-TIME PRODUCT SIGNAL CONTAINING ADD-ON INFORMATION AND HAVING FREQUENCY COMPONENTS WHICH ARE LOCATED IN A LOW ENERGY PORTION OF THE TV SIGNAL. INTERFERENCE BETWEEN THE ADD-ON AND TV SIGNALS IS MINIMIZED DUE TO THE NOISE-LIKE CHARACTERISTICS OF THE HIGH FREQUENCYTIME PRODUCT ADD-ON SIGNAL AND TO THE PARTICULAR LOCATION OF THE ADD-ON SIGNAL IN THE TV FREQUENCY BAND THUS ALLOWING ACCURATE AND RELIABLE TRANSMISSION OF BOTH THE ADD-ON AND TV SIGNALS.
Inventors
- 👤 B Loughlin
- 👤 C Page
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:28
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/08; H04N7/081
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |