ADAPTIVE CONTROL OF TRACKING SERVO SYSTEM OF OPTICAL HEADS IN OPTICAL STORAGE DEVICES

摘要

A system and method for controlling positioning of an optical pickup unit relative to at least one track of an optical data storage medium include an adaptive track position feedback controller that compensates for defocus of an optical beam relative to the optical data storage medium associated with movement across the medium and/or disturbances in distance between a lens of the optical pickup unit relative to the optical data storage medium. A track position feedback controller may include an adaptive term or parameter based on a focus (or defocus) error signal generated by a focus position feedback controller and associated sensors or detectors of a quadrature photodiode integrated circuit (PDIC).