FOCUS SERVO INTRODUCTION DEVICE

摘要

PROBLEM TO BE SOLVED: To remove the fear of collision of an objective lens and a holder with a signal recording medium when the work distance of the objective lens of an optical pickup is shortened or the lens holder is tilted to be displaced.;SOLUTION: This device is provided with a power lens 14 in an optical pickup 30 for changing the incident angle of a laser beam made incident on an objective lens 17, and power lens actuators 18 and 29 for driving the power lens 14 in an optical axis direction. At the time of starting a focus search operation, the power lens actuators are controlled to drive the power lens 14 in an optical axis direction, and introduction to a focus servo area is detected based on a focus error signal obtained by using a received light output from a photodetector 31 disposed in the optical pickup, the focus servo is locked at the time of this detection, and the power lens is returned to an initial position while the objective lens 17 is driven to hold this locked state.;COPYRIGHT: (C)2006,JPO&NCIPI