Power correction for device for scanning a record carrier

摘要

A device for recording and/or reading a record carrier has an optical head with a laser for generating a beam via a scanning spot on a track of the carrier. A detector detects a read signal and a sensor detects a sense signal from the beam. A control unit controls the laser power to a desired value. A correction unit generates a correction signal that depends on local optical properties of the record carrier derived from the sense signal measured on at least one part of the track near the scanning spot. The device corrects the power control using the correction signal. Furthermore, the record carrier can have prerecorded control parameters for setting the correction unit.