US4591898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal-dropout correction circuit for correcting video signals disturbed by signal dropouts
Assignee: US Philips Corp
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Filing: 1984-02-03
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Granted: 1986-05-27
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Expires: 2004-02-03
Abstract
Abstract A dropout correction circuit is described. It comprises a dropout detector which compares a signal with a reference level and controls a switch which connects an output of the circuit to a line memory, in order to insert a corresponding part of a preceding line during such a dropout. In order to enable the reference level to be selected as high as possible the color carrier is extracted before the video signal is applied to the dropout detector.
Inventors
- 👤 Eeltje deBoer
- 👤 Arie Huijser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:10
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/87; H04N9/88
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
117 words
A signal dropout correction circuit for correcting video signals disturbed by signal dropouts, which circuit comprises: a storage circuit for storing at least one preceding line of a video picture, switching means for connecting a video-signal output to either an output of the storage circuit or a video-signal input, and a signal-dropout detector for comparing the level of the video signal with a reference level in order to switch the switching means to such a position that the storage circuit is read out when the level of video signal drops below said reference level, and a filter circuit for extracting the colour carrier from the video signal before the video signal is applied to the dropout detector.
Claim 2
Dependent Claim
117 words
A signal dropout correction circuit for correcting video signals disturbed by signal dropouts, which circuit comprises: a storage circuit for storing at least one preceding line of a video picture, switching means for connecting a video-signal output to either an output of the storage circuit or a video-signal input, and a signal-dropout detector for comparing the level of the video signal with a reference level in order to switch the switching means to such a position that the storage circuit is read out when the level of video signal drops below said reference level, and a filter circuit for extracting the colour carrier from the video signal before the video signal is applied to the dropout detector.
Claim 3
Dependent Claim
40 words
The circuit according to claim 1 including means for disabling said detector during line blanking intervals of said video signal so that during said blanking intervals said video output is connected to said video signal input by said switching means.
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) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |