Patent ID: 6172954
Filing Date: 2001-01-09
Classification: G11B

Abstract:
An asymmetry compensation apparatus comprising:input level detecting means for making a detection signal obtained by comparing the level of a reproduced signal read from a disc-shaped recording medium with a threshold to a binary signal and for outputting the binary signal as a reproduced data signal;asymmetry compensation means provided with a low-pass filter to which the detection signal is input from said input level detecting means, for compensating for asymmetry generated in the reproduced data signal by inputting as the threshold the output of the low-pass filter to said input level detecting means;signal state detecting means for detecting a state in which the state of the reproduced signal matches the specified condition; andtime constant changing means for controlling such that the time constant of the low-pass filter is changed at the specified timing when said signal state detecting means detects a state in which the state of the reproduced signal matches the specified condition.