Method for calibrating tilt in disc player

A tilt calibration method for use in a disc player, comprising:

• a disc insertion judgment step of judging whether or not a disc has been inserted onto a turntable;
• a record signal reading step of reading a record signal in which an optical pickup unit irradiates beams onto a recording surface on the disc, if a disc is inserted onto the turntable in the disc insertion judgment step;
• a RF signal output step of receiving a record signal read by the optical pickup unit in the record signal reading step, and outputting a RF signal filtered and shaped from the received record signal;
• a peak voltage comparison step of receiving a RF signal and comparing a peak voltage of the received RF signal with a preset reference peak voltage;
• a tilt calibration step of making the turntable rotate if the RF signal peak voltage is not same as the preset reference peak voltage, in the result of the peak voltage comparison step, to thereby calibrate a tilt between the optical pickup unit and the disc.

A tilt calibration method for use in a disc player comprising:

• a disc insertion judgment step of judging whether or not a disc has been inserted onto a turntable;
• a focus error output time judgment step of judging a first focus error output time at which a focus error is output during ascending and a second focus error output time at which a focus error is output during descending, in which an optical pickup unit for irradiating beams onto a recording surface on the disc is made to ascend and then descend for a predetermined time, if a disc is inserted onto the turntable in the disc insertion judgment step;
• a subtraction step of subtracting the first focus error output time from the second focus error output time, both of which have been judged in the focus error output time judgment step, and outputting a focus error output difference time;
• a disc recording surface judgment step of subtracting a reference focus error output difference time which is preset when the recording surface on the disc is normal from the focus error output difference time output from the subtraction step, and judging a crooked state of the recording surface on the disc;
• a first tilt calibration step of making the turntable rotate if the focus error output difference time is not same as the reference focus error output difference time, in the result of the disc recording surface judgment step, to thereby calibrate a tilt between the optical pickup unit and the disc so that the focus error output difference time is same as the reference focus error output difference time;
• a record signal reading step of reading a record signal in which an optical pickup unit irradiates beams onto a recording surface on the disc, after the first tilt calibration step;
• a RF signal output step of receiving a record signal read by the optical pickup unit in the record signal reading step, and outputting a RF signal filtered and shaped from the received record signal;
• a peak voltage comparison step of receiving a RF signal and compares a peak voltage of the received RF signal with a preset reference peak voltage;
• and
• a second tilt calibration step of making the turntable rotate if the RF signal peak voltage is not same as the preset reference peak voltage, in the result of the peak voltage comparison step, to thereby calibrate a tilt between the optical pickup unit and the disc so that the RF signal peak voltage is same as the preset reference peak voltage.