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US5517476A
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Digital signal reproducing apparatus using a viterbi decoder
Assignee: Pioneer Corp
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Filing: 1995-01-30
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Granted: 1996-05-14
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Expires: 2015-01-30
Abstract
Abstract A digital signal reproducing apparatus which can reproduce a digital signal without deteriorating the performance of a Viterbi decoder being deteriorated even if a positional error due to some mechanism causes in reproducing information from a recording medium or amplitude fluctuation in a red signal due to fluctuation in characteristics of the recording medium should occur. The digital signal reproducing apparatus performs an A/D conversion of a read signal read from the recording medium to convert it to a digital sample value series, obtains an amplitude value according to a result of subtraction between a maximum sample value having a maximum level of sample values in the sample value series and a minimum sample value having a minimum level of sample values in said sample value series, and supplies a value obtained by uniformly each of the estimated sample values in a Viterbi decoder by this amplitude value as a final estimated sample value to the Viterbi decoder.
Inventors
- 👤 Hideki Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:44
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009; G11B20/10037; G11B20/10268; G11B20/10287; G11B20/10296
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
174 words
A digital signal reproducing apparatus for obtaining a regenerated digital signal by reproducing record information from a read signal read from a recording medium on which digital signals are recorded, said digital signal reproducing apparatus comprising: an A/D convertor for successively sampling said read signal and converting the signal to a digital sample value series, a sample value extracting means for extracting a maximum sample value having a maximum level and a minim sample value having a minimum level from sample values in said sample value series, an amplitude value detecting means for obtaining an amplitude value according to a result of subtraction between said maximum sample value and said minimum sample value and generating an amplitude signal corresponding to said amplitude value, a dividing means for obtaining a result of dividing each of the sample values in said sample value series by a value corresponding to said amplitude signal as an amplitude-corrected sample value, and a decoding means for executing decoding according to said amplitude-corrected sample value to obtain a regenerated digital signal.
Claim 2
Dependent Claim
174 words
A digital signal reproducing apparatus for obtaining a regenerated digital signal by reproducing record information from a read signal read from a recording medium on which digital signals are recorded, said digital signal reproducing apparatus comprising: an A/D convertor for successively sampling said read signal and converting the signal to a digital sample value series, a sample value extracting means for extracting a maximum sample value having a maximum level and a minim sample value having a minimum level from sample values in said sample value series, an amplitude value detecting means for obtaining an amplitude value according to a result of subtraction between said maximum sample value and said minimum sample value and generating an amplitude signal corresponding to said amplitude value, a dividing means for obtaining a result of dividing each of the sample values in said sample value series by a value corresponding to said amplitude signal as an amplitude-corrected sample value, and a decoding means for executing decoding according to said amplitude-corrected sample value to obtain a regenerated digital signal.
Claim 3
Dependent Claim
81 words
A digital signal reproducing apparatus according to claim 1, wherein a mirror surface section and an isolated pit for synchronism detection are formed in said recording medium, and said sample value extracting means extracts a sample value corresponding to said mirror section on the sample values in said sample value series as said minimum sample value and also extracts a sample value corresponding to said isolated pint as said maximum sample value of the sample values in said sample value series.
Claim 4
Dependent Claim
55 words
A digital signal reproducing apparatus according to claim 1, wherein said recording medium stores a specified pattern signal recorded therein, and said sample value extracting means extracts said maximum sample and the minimum sample value of sample values in a specified sample value spring corresponding to said specified pattern signal among said sample value series.
Claim 5
Dependent Claim
84 words
A digital signal reproducing apparatus according to claim 1, wherein said recording medium stores information signals recorded therein based on the partial response system, and said sample value extracting means extracts a sample value having a level higher than a specified first level from sample values in said sample value series as said maximum sample value and also extracts a sample value having a level lower than a specified second level from sample values in said sample value series as said minimum sample value.
Claim 6
Dependent Claim
17 words
A digital signal reproducing apparatus according to claim 1, wherein said decoding means is a Viterbi decoder.
References Cited (Backward Citations)
US5448544A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-14 | 1999-11-13 | 2000-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-14 | 2003-11-13 | 2004-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-14 | 2007-11-13 | 2008-05-14 | $7700.00 | Window Closed / Lapsed |