AN OPTICAL APPARATUS CAPABLE OF GENERATING ADAPTIVE CONTROL SIGNALS

摘要

The present invention discloses an optical apparatus capable of reproducing/recording information from/to an optical carrier, e.g. a DVD or BD disk. The apparatus has control means for positioning/focusing a radiation beam (5) on the carrier and photo detection means for detection of radiation reflected from the carrier. Additionally, defect detection means (DEFO) for detection of surface defect areas (Al, A2) can indicate where surface defects, e.g. scratches etc., are present. Processing means are adapted for integrating, and preferably differentiate, error signals (RE, FE) immediately after the beam (5.b) is exiting a defect area (Al) for generating adaptive control signals (AD_ RE, AD_ FE). The optical system is adapted to apply the adaptive control signals (AD_ RE, AD_ FE) when the beam is positioned in the defect area (Al) again, thereby reducing off-track deviation as the beam (5.d) exits the defect area (Al).