Optical pickup apparatus with a crosstalk balance detecting circuit

摘要

An optical pickup apparatus for properly detecting crosstalk amounts to a read signal for one track from adjacent tracks thereof and their balance. A difference between a second read signal value for one track at a time point when a first read signal value for one adjacent track is smaller than a first threshold value and a third read signal value for the other adjacent track is larger than a second threshold value and a second read signal value at a time point when the first read signal value is larger than the second threshold value and the third read signal value is smaller than the first threshold value is formed as a value indicative of a balance level of crosstalks to the second read signal. A difference between a second read signal value at a time point when the first read signal value is larger than the second threshold value and the third read signal value is larger than the second threshold value and a second read signal value at a time point when the first read signal value is smaller than the first threshold value and the third read signal value is smaller than the first threshold value is formed as a value indicative of a crosstalk amount to the second read signal.