METHOD FOR CALCULATING AMOUNT OF DEFLECTION IN OPTICAL INFORMATION STORAGE MEDIUM, AND APPARATUS FOR WRITING AND READING USING THE SAME

摘要

PURPOSE: A method for calculating the amount of deflection in an optical information storage medium, and an apparatus for writing and reading using the same are provided to stabilize rotation speed by previously calculating the amount of deflection. CONSTITUTION: A shape of a deflection signal generated in one rotation period of an optical information storage medium is presumed as a sine wave having the same frequency as rotation frequency(400). After fixing an optical pick-up at one position, a time gap is measured between focus error signals of the S curve generated during one period when the information storage medium rotates(410-420). After fixing an optical pick-up at other positions, a time gap is measured between focus error signals of the S curve generated during one period when the information storage medium rotates(430-440). The amount of deflection is calculated by using two time gaps and position change of the optical pick-up(450).