US4686583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dropout compensating apparatus using a digital delay circuit
Assignee: Panasonic Holdings Corp
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Filing: 1984-10-17
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Granted: 1987-08-11
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Expires: 2004-10-17
Abstract
Abstract A dropout compensating apparatus used in a video signal recording/reproducing apparatus employs a digital delay circuit such as a digital memory. An input video signal is converted to a digital signal by an A/D converter. The digital signal is applied via a first switch to the digital delay circuit where it is delayed by a specified period. The delayed digital signal is converted to a delayed video signal by a D/A converter. The delayed video signal is applied to a second switch. A dropout detector produces a dropout detected signal when a dropout occurs in the input video signal. The first switch normally passes the digital signal from the A/D converter and is responsive to the dropout detected signal for passing the delayed digital signal from the digital delay circuit back to the digital delay circuit. The second switch normally passes the input video signal as it is and is also responsive to the dropout detected signal for passing the delayed video signal from the D/A converter.
Inventors
- 👤 Masao Tomita
- 👤 Akio Hashima
- 👤 Haruo Ohta
- 👤 Tadaaki Matsuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:52
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/94; H04N5/911
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
244 words
A dropout compensating apparatus for eliminating a dropout contained in a video signal recording medium, comprising: analog to digital converting means for converting an input video signal to a digital signal; digital delaying means for delaying a digital signal by a specified period; dropout detecting means responsive to an input video signal containing a dropout for producing a dropout detected signal; digital to analog converting means for converting a delayed digital signal from said digital delaying means to a delayed video signal; first switch means having two input terminals respectively connected with an output terminal of said analog to digital converting means and an output of said digital delaying means and an output terminal connected with an input terminal of said digital delaying means, said first switch means being responsive to said dropout detected signal for selectively connecting the two input terminals with the output terminal thereof so that the digital delayed signal from the digital delaying means is applied to the input terminal of said digital delaying means only when the input video signal contains a dropout; and second switch means responsive to said dropout detected signal for selectively passing the input video signal and the delayed video signal from said digital to analog converting means so that the delayed video signal from said digital to analog converting means is passed through said second switch means only when the input video signal contains a dropout, thereby to obtain a dropout compensated video signal.
Claim 2
Dependent Claim
244 words
A dropout compensating apparatus for eliminating a dropout contained in a video signal recording medium, comprising: analog to digital converting means for converting an input video signal to a digital signal; digital delaying means for delaying a digital signal by a specified period; dropout detecting means responsive to an input video signal containing a dropout for producing a dropout detected signal; digital to analog converting means for converting a delayed digital signal from said digital delaying means to a delayed video signal; first switch means having two input terminals respectively connected with an output terminal of said analog to digital converting means and an output of said digital delaying means and an output terminal connected with an input terminal of said digital delaying means, said first switch means being responsive to said dropout detected signal for selectively connecting the two input terminals with the output terminal thereof so that the digital delayed signal from the digital delaying means is applied to the input terminal of said digital delaying means only when the input video signal contains a dropout; and second switch means responsive to said dropout detected signal for selectively passing the input video signal and the delayed video signal from said digital to analog converting means so that the delayed video signal from said digital to analog converting means is passed through said second switch means only when the input video signal contains a dropout, thereby to obtain a dropout compensated video signal.
Claim 3
Dependent Claim
18 words
A dropout compensating apparatus according to claim 1, wherein said specified period is a one horizontal synchronizing period.
Claim 4
Dependent Claim
35 words
A dropout compensating apparatus according to claim 2, further comprising low-pass filters arranged respectively before said analog to digital converting means and after said digital to analog converting means for eliminating unnecessary high frequency components.
Claim 5
Dependent Claim
32 words
A dropout compensating apparatus according to claim 2, wherein said digital delaying means comprises a digital memeory which stores a digital signal corresponding to a video signal included in said specified period.
Claim 6
Dependent Claim
31 words
A dropout compensating apparatus according to claim 4, wherein the delay time of the delayed digital signal applied to said digital to analog converting means is shorter than said specified period.
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) | 1990-08-10 | 1991-02-09 | 1991-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-10 | 1995-02-09 | 1995-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-10 | 1999-02-09 | 1999-08-11 | $7700.00 | Window Closed / Lapsed |