US 6,445,662 B1 · Reproducing apparatus · patentgrep

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Abstract

A reproducing apparatus includes a first device for reproducing a signal of a run-length-limited code from a recording medium. A transversal filter subjects the signal reproduced by the first device to a partial-response waveform equalization to generate an equalization-resultant signal. The partial-response waveform equalization depends on tap coefficients. A second device operates for detecting whether or not the signal reproduced by the first device corresponds to a zero-cross point, and generating 0-point information in response to a result thereof. A delay circuit responsive to the 0-point information generated by the second device operates for outputting at least three successive samples of the 0-point information. A temporary decision device operates for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal. The PR mode signal represents a type of the partial-response waveform equalization. The RLL mode signal represents a type of the run-length-limited code. A third device operates for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference. A fourth device operates for controlling the tap coefficients of the transversal filter in response to the error signal generated by the third device.

Claims24

Dependent claims

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a transversal filter subjecting the signal reproduced by the first means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
second means for detecting whether or not the signal reproduced by the first means corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the second means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
third means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
and
fourth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the third means.

5 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a transversal filter subjecting the signal reproduced by the first means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
second means for detecting whether or not the equalization-resultant signal generated by the transversal filter corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the second means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
third means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
and
fourth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the third means.

5 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a subtracter for subtracting a DC offset signal from the signal reproduced by the first means to generate a subtraction-resultant signal;
second means for subjecting the subtraction-resultant signal generated by the subtracter to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the error signal in response to one of the successive samples of the 0-point information, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
second means for subjecting the signal reproduced by the first means to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
a subtracter for subtracting a DC offset signal from the equalization-resultant signal generated by the transversal filter to generate a subtraction-resultant signal;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the error signal in response to one of the successive samples of the 0-point information, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a subtracter for subtracting a DC offset signal from the signal reproduced by the first means to generate a subtraction-resultant signal;
second means for subjecting the subtraction-resultant signal generated by the subtracter to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the error signal in response to the temporary decision value, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
second means for subjecting the signal reproduced by the first means to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
a subtracter for subtracting a DC offset signal from the equalization-resultant signal generated by the transversal filter to generate a subtraction-resultant signal;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the error signal in response to the temporary decision value, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a subtracter for subtracting a DC offset signal from the signal reproduced by the first means to generate a subtraction-resultant signal;
second means for subjecting the subtraction-resultant signal generated by the subtracter to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the equalization-resultant signal in response to at least one of the successive samples of the 0-point information, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
second means for subjecting the signal reproduced by the first means to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
a subtracter for subtracting a DC offset signal from the equalization-resultant signal generated by the transversal filter to generate a subtraction-resultant signal;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the equalization-resultant signal in response to one of the successive samples of the 0-point information, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
a subtracter for subtracting a DC offset signal from the signal reproduced by the first means to generate a subtraction-resultant signal;
second means for subjecting the subtraction-resultant signal generated by the subtracter to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the equalization-resultant signal in response to the temporary decision value, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

A reproducing apparatus comprising:

first means for reproducing a signal of a run-length-limited code from a recording medium;
second means for subjecting the signal reproduced by the first means to a re-sampling process to generate a re-sampling resultant signal;
a transversal filter subjecting the re-sampling resultant signal generated by the second means to a partial-response waveform equalization to generate an equalization-resultant signal, the partial-response waveform equalization depending on tap coefficients;
a subtracter for subtracting a DC offset signal from the equalization-resultant signal generated by the transversal filter to generate a subtraction-resultant signal;
third means for detecting whether or not the re-sampling resultant signal corresponds to a zero-cross point, and generating 0-point information in response to a result of said detecting;
a delay circuit responsive to the 0-point information generated by the third means for outputting at least three successive samples of the 0-point information;
a temporary decision device for calculating a temporary decision value of the equalization-resultant signal on the basis of a PR mode signal, an RLL mode signal, the successive samples of the 0-point information which are outputted from the delay circuit, and an actual value of the equalization-resultant signal, the PR mode signal representing a type of the partial-response waveform equalization, the RLL mode signal representing a type of the run-length-limited code;
fourth means for calculating a difference between the temporary decision value of the equalization-resultant signal and the actual value thereof, and generating an error signal in response to the calculated difference;
fifth means for controlling the tap coefficients of the transversal filter in response to the error signal generated by the fourth means;
and
an error calculator for selecting 0-corresponding components from the equalization-resultant signal in response to the temporary decision value, and generating the DC offset signal in response to the selected 0-corresponding components and outputting the DC offset signal to the subtracter.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/468,130Filed 21 Dec 1999
Priority: JP 10-36674624 Dec 1998
Granted: 3 Sep 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G11B 20/10009
Digital recording or reproducing: improvement or modification of read or write signals
G11B 20/10083
Using partial response filtering when writing the signal to the medium or reading it therefrom: pR1 or PR, i.e. partial response class 1,…
G11B 20/10111
Using partial response filtering when writing the signal to the medium or reading it therefrom: partial response PR
G11B 20/10148
Using partial response filtering when writing the signal to the medium or reading it therefrom: partial response PR

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