Abstract: The present invention relates to determining an optimised write power used for writing electronic data on optical disc and includes a method, a device and a computer program product for determining a write power for writing electronic data on a medium (32,108), based on a sequence of written data, using a power control model including a written data deviation measure, a written data asymmetry and a written data asymmetry target value, comprising the steps determining the written data deviation measure for the sequence of written data (step 202), adjusting the written data asymmetry target value in relation to the written data asymmetry, if the written data deviation measure has changed (steps 218, 220, 226, 228), determining the write power in dependence of written data asymmetry (step 210), and writing another sequence of data on the medium using said determined write power (step 212), so as to obtain power optimised writing of data.

Abstract: A device for recording information in a track on a record carrier writes and reads marks and spaces each having a nominal run length. The device has a detection unit (32) for generating a signed deviation value signal (34) indicative for a position deviation of a starting edge of a mark and/or an ending edge of a mark with respect to a nominal, position of said edge. A calculation unit (31) selects at least one predefined run length pattern and determines a correction signal (33) based on at least one statistically calculated parameter of the signed deviation value signal for the selected run length pattern. A radiation source control unit (29) controls the power of the radiation source during said writing based on the correction signal.