Patent ID: 6876616

Claim:
A digital signal reproducing apparatus comprising: DC controlling means for controlling a DC level of a reproduced signal in response to a DC level control signal; sampling means for sampling an output signal from the DC controlling means to generate a sampling-resultant signal; filtering means for filtering the sampling-resultant signal into a filtering-resultant signal; binarizing means for converting one of (1) the sampling-resultant signal and (2) the filtering-resultant signal into a binary signal; DC level control signal generating means for generating the DC level control signal in response to the binary signal, and for outputting the DC level control signal to the DC controlling means; code offset detecting means for detecting an offset in a modulation-resultant-code pattern in response to the binary signal, and for generating code pattern offset information in response to the detected offset in the modulation-resultant-code pattern; offset-responsive controlling means for implementing one of (1) changing a response characteristic of a loop formed by the DC controlling means, the sampling means, the binarizing means, and the DC level control signal generating means and (2) suspending the DC level control by the DC controlling means in response to the code pattern offset information; subtracting means for subtracting a DC offset signal from one of (1) the reproduced signal, (2) the sampling-resultant signal, and (3) the filtering-resultant signal to generate a subtraction-resultant signal; and DC offset extracting means for extracting low-frequency components from one of (1) the sampling-resultant signal, (2) the filtering-resultant signal, and (3) the subtraction-resultant signal as the DC offset signal, the low-frequency components corresponding to zero-cross sampling points.