OPTICAL DISK MASTER DISK EXPOSING APPARATUS AND METHOD FOR DETECTING DEFLECTION AMOUNT OF ASYNCHRONOUS ROTATION

PROBLEM TO BE SOLVED: To detect an asynchronous rotation deflection with high accuracy and to change a beam emission position on an optical disk master disk in a radial direction so as to stabilize a track pitch of a locus of beam emission with high accuracy. SOLUTION: An asynchronous rotation deflection amount detection section 19a receives an output of a rotation deflection sensor 17 placed contactlessly with a turntable 10, detects a rotation deflection amount of the turntable 10, and is provided with: an amplifier 30; an analog/digital converter 31; an encoder 15 for detecting a rotary angle of an SP motor 14, a micro controller 32 for calculating a synchronous rotation deflection amount of the turntable 10 on the basis of an output of the amplifier 30 and the analog/digital converter 31 and a detected value of the encoder 15; and a piezoelectric element 18 for displacing the position of the rotation deflection sensor 17 on the basis of the synchronous rotation deflection amount. COPYRIGHT: (C)2003,JPO