Patent US4701812A successfully refreshed from Google Patents.
US4701812A
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PCM recording and reproducing apparatus
Assignee: Mitsubishi Electric Corp
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Filing: 1985-06-18
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Granted: 1987-10-20
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Expires: 2005-06-18
Abstract
Abstract A PCM recording and reproducing apparatus provided with an overdubbing function includes an error-correcting device employing error-correcting redundant signals recorded apart from the audio tracks. The apparatus functions to prevent error correction when the use of the redundant signals would cause the audio tracks to be corrected in error.
Inventors
- 👤 Kunimaro Tanaka
- 👤 Minoru Ozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:46
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1806; G11B20/1809; G11B20/1816; G11B2020/183
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
202 words
A PCM recording and reproducing apparatus comprising: means for initialy assigning a single track or a plurality of tracks on a recording medium per channel of an original audio signal and for recording the audio signal as a digital signal on said tracks; means for generating error-correcting redundant signals from the channels of audio signals and for subsequently recording the error-correcting redundant signals on a plularity of tracks different from said initial tracks; means for adding an error-detecting redundant signal to each of said subsequent tracks; means for rewriting the original audio signal in a certain channel and the corresponding errorcorrecting redundant signal in an overdubbing process in which a new audio signal is rerecorded in said certain channel while reproducing the original audio signal that has already been recorded; means for issuing an errorcorrection inhibit signal per track when an error in excess of a predetermined error-correcting ability is produced in a portion of a recording medium where said original audio signal is reproduced; and means for detecting a track where the signal is not rerecorded from the error-correction inhibit signals and for forcibly bringing the error-correcting redundant signal into error when at least one error-correction inhibit track is not recorded.
Claim 2
Dependent Claim
202 words
A PCM recording and reproducing apparatus comprising: means for initialy assigning a single track or a plurality of tracks on a recording medium per channel of an original audio signal and for recording the audio signal as a digital signal on said tracks; means for generating error-correcting redundant signals from the channels of audio signals and for subsequently recording the error-correcting redundant signals on a plularity of tracks different from said initial tracks; means for adding an error-detecting redundant signal to each of said subsequent tracks; means for rewriting the original audio signal in a certain channel and the corresponding errorcorrecting redundant signal in an overdubbing process in which a new audio signal is rerecorded in said certain channel while reproducing the original audio signal that has already been recorded; means for issuing an errorcorrection inhibit signal per track when an error in excess of a predetermined error-correcting ability is produced in a portion of a recording medium where said original audio signal is reproduced; and means for detecting a track where the signal is not rerecorded from the error-correction inhibit signals and for forcibly bringing the error-correcting redundant signal into error when at least one error-correction inhibit track is not recorded.
Claim 3
Dependent Claim
58 words
A PCM recording and reproducing apparatus according to claim 1, wherein said means for forcibly bringing the error-correcting redundant signal into error includes means for delaying the error-correction inhibit signal and a signal indicative of whether the audio signal is recorded or not for a period of time corresponding to a signal processing delay time for each track.
Claim 4
Dependent Claim
27 words
A PCM recording and reproducing apparatus according to claim 1 wherein said means for forcibly bringing the error-correcting redundant signal into error records frame synchronizing signals correctly.
Claim 5
Dependent Claim
27 words
A PCM recording and reproducing apparatus according to claim 2 wherein said means for forcibly bringing the error-correcting redundant signal into error records frame synchronizing signals correctly.
Claim 6
Dependent Claim
45 words
A PCM recording and reproducing apparatus according to claim 1, 2, 3 or 4, wherein said means for forcibly bringing the error-correcting redundant signal into error includes means for equalizing all of said error-correcting redundant signals and said errordetecting redundant signals to "0" or "1".
Claim 7
Dependent Claim
17 words
A PCM recording and reproducing apparatus according to claim 1 wherein said recording medium is magnetic tape.
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) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |