US4860121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detector circuit for detecting drop-out in reproduced digital data
Assignee: Pioneer Corp
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Filing: 1988-03-18
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Granted: 1989-08-22
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Expires: 2008-03-18
Abstract
Abstract A drop-out detector circuit for use in a data reproducing device in which a reproduced high-frequency signal is digitized. The most significant bit of the digitized signal is sampled, and its logic state detected over a predetermined number of sampling periods. Both high- and low-frequency drop-outs can be detected from the detected logic state pattern of the most significant bit.
Inventors
- 👤 Toshio Gotoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:16
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1806; H; H04; H04N; H04N9/00; H04N9/79; H04N9/87; H04N9/88; H04N9/882; H04N9/885
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A drop-out detector circuit for a device for reproducing sequentially recorded digital data from a signal recorded on a recording medium, the recorded signal comprising a high-frequency modulated signal, comprising: means for reading said signal recorded on said recording medium and producing a digitized signal therefrom; means for extracting from each of a plurality of sequential data values contained within said digitized signal at least one bit indicative of a polarity of the respective data value; and means for detecting when a sequence of a predetermined number of the bits extracted from a plurality of said sequential data values is in a predetermined bit pattern, an output of said detecting means forming a drop-out signal.
Claim 2
Dependent Claim
115 words
A drop-out detector circuit for a device for reproducing sequentially recorded digital data from a signal recorded on a recording medium, the recorded signal comprising a high-frequency modulated signal, comprising: means for reading said signal recorded on said recording medium and producing a digitized signal therefrom; means for extracting from each of a plurality of sequential data values contained within said digitized signal at least one bit indicative of a polarity of the respective data value; and means for detecting when a sequence of a predetermined number of the bits extracted from a plurality of said sequential data values is in a predetermined bit pattern, an output of said detecting means forming a drop-out signal.
Claim 3
Dependent Claim
24 words
The drop-out detector circuit of claim 1, wherein said predetermined bit pattern comprises a plurality of data bits all in the same logic state.
Claim 4
Dependent Claim
51 words
The drop-out detector circuit of claim 1, wherein said detecting means comprises: means for storing a standard data bit pattern; and means for comparing said sequence of a predetermined number of said at least one bits extracted from a plurality of said sequential data values with said standard data bit pattern.
Claim 5
Dependent Claim
20 words
The drop-out detector circuit of claim 1, wherein said at least one bit comprises at least one most significant bit.
Claim 6
Dependent Claim
129 words
A drop-out detector circuit for a device for reproducing sequentially recorded digital data from a signal recorded on a recording medium, the recorded signal including a high-frequency modulated signal, comprising: means for reading said signal recorded on said recording medium and producing a digitized signal therefrom; means for delaying said digitized signal by a period equivalent to a period of one digital value contained therein; means for subtracting from an output of said delaying means a present digital value contained in said digitized signal; means for storing most significant bits of a predetermined number of sequential output values of said subtracting means; and means for detecting when a sequence of a predetermined number of said most significant bits stored by said storing means is in a predetermined bit pattern.
Claim 7
Dependent Claim
129 words
A drop-out detector circuit for a device for reproducing sequentially recorded digital data from a signal recorded on a recording medium, the recorded signal including a high-frequency modulated signal, comprising: means for reading said signal recorded on said recording medium and producing a digitized signal therefrom; means for delaying said digitized signal by a period equivalent to a period of one digital value contained therein; means for subtracting from an output of said delaying means a present digital value contained in said digitized signal; means for storing most significant bits of a predetermined number of sequential output values of said subtracting means; and means for detecting when a sequence of a predetermined number of said most significant bits stored by said storing means is in a predetermined bit pattern.
Claim 8
Dependent Claim
24 words
The drop-out detector circuit of claim 5, wherein said predetermined bit pattern is a set of data bits all in the same logic state.
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) | 1992-08-21 | 1993-02-20 | 1993-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-21 | 1997-02-20 | 1997-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-21 | 2001-02-20 | 2001-08-22 | $7700.00 | Window Closed / Lapsed |