Patent US4849957A successfully refreshed from Google Patents.
US4849957A
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Digital signal reproducing circuit
Assignee: Toshiba Corp
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Filing: 1987-09-29
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Granted: 1989-07-18
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Expires: 2007-09-29
Abstract
Abstract An apparatus for reproducing digital record signals subjected to a predetermined frequency characteristic in a recording process and digital record signals not subjected to the frequency characteristic, the digital record signals including data for discrimination of the predetermined frequency characteristic. The apparatus includes an input terminal for receiving digital record signals, a circuit for detecting the predetermined frequency characteristic discrimination data, a digital processing circuit responsive to the detecting circuit for selectively giving the digital record signals applied from the input terminal a first prescribed frequency characteristic corresponding to the predetermined frequency characteristic in the recording or a second prescribed frequency characteristic, a digital-to-analog converter for converting the digital record signals applied from the digital processing circuit to analog signals and an amplifier for amplifying the analog signals applied from the digital-to-analog converter with a prescribed frequency characteristic capable of compensating for the predetermined frequency characteristic in the recording.
Inventors
- 👤 Hiroshi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:30
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10527; G11B20/10009
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
156 words
Apparatus for reproducing digital record signals subjected to a predetermined frequency characteristic in a recording process and digital record signals not subjected to the frequency characteristic, the digital record signals including data for discrimination of the predetermined frequency characteristic, comprising: input means for receiving digital record signals; means for detecting the predetermined frequency characteristic discrimination data; digital means responsive to the detecting means for selectively giving the digital record signals received from the input means a first prescribed frequency characteristic including the predetermined frequency characteristic or a second prescribed frequency characteristic without including the predetermined frequency characteristic respectively according to whether the predetermined frequency characteristic data is not or is detected; digital-to-analog conversion means for converting the digital record signals received from the digital means to analog signals; and means for amplifying the analog signals received from the digital-to-analog conversion means with a prescribed frequency characteristic that is capable of compensating for the predetermined frequency characteristic.
Claim 2
Dependent Claim
156 words
Apparatus for reproducing digital record signals subjected to a predetermined frequency characteristic in a recording process and digital record signals not subjected to the frequency characteristic, the digital record signals including data for discrimination of the predetermined frequency characteristic, comprising: input means for receiving digital record signals; means for detecting the predetermined frequency characteristic discrimination data; digital means responsive to the detecting means for selectively giving the digital record signals received from the input means a first prescribed frequency characteristic including the predetermined frequency characteristic or a second prescribed frequency characteristic without including the predetermined frequency characteristic respectively according to whether the predetermined frequency characteristic data is not or is detected; digital-to-analog conversion means for converting the digital record signals received from the digital means to analog signals; and means for amplifying the analog signals received from the digital-to-analog conversion means with a prescribed frequency characteristic that is capable of compensating for the predetermined frequency characteristic.
Claim 3
Dependent Claim
59 words
The apparatus of claim 1 wherein the digital means gives the digital record signals a prescribed pre-emphasis frequency characteristic corresponding to an equivalent pre-emphasis frequency characteristic in the recording process as said first prescribed frequency characteristic and to amplifying means amplifies the analog signals with a prescribed de-emphasis frequency characteristic which is capable of compensating the pre-emphasis frequency characteristic.
Claim 4
Dependent Claim
28 words
The apparatus of claim 2 wherein the digital means operates in response to an emphasis discrimination data corresponding to the equivalent pre-emphasis frequency characteristic in the recording process.
Claim 5
Dependent Claim
35 words
The apparatus of claim 3 wherein the emphasis discrimination data indicates whether the digital record signals are subjected to the pre-emphasis frequency characteristic in the recording process or not subjected to the pre-emphasis frequency characteristic.
Claim 6
Dependent Claim
18 words
The apparatus of claim 4 wherein the digital means includes digital filter means having the pre-emphasis frequency characteristic.
Claim 7
Dependent Claim
20 words
The apparatus of claim 2 wherein the amplifying means includes a feed back circuit means with the de-emphasis frequency characteristics.
Claim 8
Dependent Claim
20 words
The apparatus of claim 6 wherein the analog signals are applied to the amplifying means through a low pass filter.
Claim 9
Dependent Claim
150 words
Apparatus for reproducing digital record signals subjected to a predetermined frequency characteristic in a recording process and digital record signals not subjected to the frequency characteristic, the digital record signals including data for discrimination of the predeterined frequency characteristic, comprising: input means for receiving digital record signals; means for detecting the predetermined frequency characteristic discrimination data in the digital record signals; digital means, responsive to the detecting means and coupled to receive the digital record signals from the input means, for selectively giving the digital record signals the predetermined frequency characteristic upon said detecting means detecting that the predetermined frequency characteristic is absent from the digital record signals; digital-to-analog conversion means for converting the digital record signals received from the digital means to analog signals; and means for amplifying the analog signals received from the digital-to-analog conversion means with a prescribed frequency characteristic that compensates for the predetermined frequency characteristic.
Claim 10
Dependent Claim
150 words
Apparatus for reproducing digital record signals subjected to a predetermined frequency characteristic in a recording process and digital record signals not subjected to the frequency characteristic, the digital record signals including data for discrimination of the predeterined frequency characteristic, comprising: input means for receiving digital record signals; means for detecting the predetermined frequency characteristic discrimination data in the digital record signals; digital means, responsive to the detecting means and coupled to receive the digital record signals from the input means, for selectively giving the digital record signals the predetermined frequency characteristic upon said detecting means detecting that the predetermined frequency characteristic is absent from the digital record signals; digital-to-analog conversion means for converting the digital record signals received from the digital means to analog signals; and means for amplifying the analog signals received from the digital-to-analog conversion means with a prescribed frequency characteristic that compensates for the predetermined frequency characteristic.
Claim 11
Dependent Claim
58 words
The apparatus of claim 8 wherein the digital means selectively gives the digital record signals a prescribed pre-emphasis frequency characteristic corresponding to an equivalent pre-emphasis frequency characteristic in the recording as said predetermined frequency characteristic and the amplifying means amplifies the analog signals with a prescribed de-emphasis frequency characteristic that is capable of compensating the pre-emphasis frequency characteristic.
Claim 12
Dependent Claim
28 words
The apparatus of claim 9 wherein the digital means operates in response to an emphasis discrimination data corresponding to the equivalent pre-emphasis frequency characteristic of the recording process.
Claim 13
Dependent Claim
35 words
The apparatus of claim 10 wherein the emphasis discrimination data indicates whether the digital record signals are subjected to the pre-emphasis frequency characteristic in the recording process or not subjected to the pre-emphasis frequency characteristic.
Claim 14
Dependent Claim
20 words
The apparatus of claim 9 wherein the amplifying means includes a feed back circuit means with the de-emphasis frequency characteristic.
Claim 15
Dependent Claim
20 words
The apparatus of claim 12 wherein the analog signals are applied to the amplifying means through a low pass filter.
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) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |