Optimum slice level signal reading apparatus for optical disk

An apparatus for reading information recorded on an optical disk, comprising:

• a rotator to rotate the optical disk at a rotating frequency;
• a detector to read information recorded on the optical disk and to output reading signals corresponding to the information;
• an AC coupling section to filter the reading signal so as to eliminate frequency components lower than a predetermined cut-off frequency and to output the filtered reading signal, wherein the predetermined cut-off frequency is 1/10 to 80 times the rotating frequency of the rotator;
• a slice level signal generator to generate a slice level signal;
• a data detector having a binary comparator to compare the filtered reading signals with the slice level signal so as to output binary signals;
• a phase comparator to generate a phase reference signal, to compare a phase of the binary signals with that of the phase reference signal, and to output a phase difference signal;
• and
• the slice level signal generator adjusting the slice level signal such that the phase of the binary signal coincides with that of the phase reference signal.