Patent ID: 6714496
Filing Date: 2004-03-30
Classification: G11B

Abstract:
A method for calibrating a tilt in a disc player, the tilt calibration method 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; 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; and a 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.