Koninklijke Philips Corporation N.v.

Philips & Lite-on Digital Solutions Corporation

Stefan Geusens

Maarten Kuijper

Johannes Leopoldus Bakx

Jeroen Arnoldus Leonardus Johannes Raaymakers

Sung-Yao Lin

Antoon Dekker

Mohamad-Hussein El Husseini

Stefan Hendrik Guillaume Steven

A method and system for obtaining focus optimization in an optical disc system is disclosed. The focus offset of a recording unit is set to a first of a plurality of predetermined values. A HF quality value is measured and stored for the selected focus offset value of the recording unit. The focus offset is then set to a best-known focus offset value. Tracks on the optical media being read are then jumped. The above steps are then repeated for each of the plurality of predetermined focus offset values. The optimal focus setting is then determined from the stored HF quality measurements.

Focus optimization routine with sub-optimal jump settings in optical disc systems

In a tracking control method for use in an optical disk drive to read/write an optical disk, an open-loop tracking control operation of the optical disk drive is first performed according to an input tracking error signal and a predetermined periodical offset to generate a dynamic offset. Afterwards, a closed-loop tracking control operation of the optical disk drive is performed according to the input tracking error signal calibrated with the dynamic offset.

Tracking control method for reading/writing optical disk

The present invention relates to a method for operating an optical drive system capable of reproducing/recording information from/to an optical carrier (), wherein a position error and a speed error of a radiation spot () on the carrier has been created due to an unreliable error signal which has been generated due to a surface defect (). The method includes the steps of registering values of e.g. servo signals, determining the occurrence of a defect using a defect detector DEFO (), generating a first and a second compensation signal and applying these compensation signals to the control system () of the optical drive system. The first compensation signal is capable of reducing the speed error and the second compensation signal is capable of reducing the position error. Thus, the application of the compensation signals immediately after the unreliable error signals reduces the position error and the speed error of the focussed radiation spot ().

Optimum tracking error compensation for improved optical disk playability

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Eindhoven, Netherlands

Stefan Geusens