FOCUS SERVO PULL-IN APPARATUS AND ITS METHOD

PROBLEM TO BE SOLVED: To ensure the optimum positioning of an optical pickup to optical disk mediums having various thicknesses utilizing an FE signal of the optical pickup itself whose positioning is to be performed without using a position sensor, and to ensure reliable pull-in of a focus servo. SOLUTION: The focus servo pull-in apparatus has: a sine wave vibrating means for vibrating an object lens in the optical pickup by a sine wave; a first binarizing means for generating binarized signals from the sine wave; a second binarizing means for generating binarized signals from focus error signals; a pulse extracting means for extracting pulses by the binarized signals generated by the first binarizing means and the binarized signals generated by the second binarizing means; and a control means for controlling an optical pickup driving means by the pulses extracted by the pulse extracting means and controlling a focus servo pull-in means so that the optical pickup is moved to the optimum focus pull-in position. COPYRIGHT: (C)2005,JPO&NCIPI