Marvell International Limited

Lite-on It Corporation

Philips & Lite-on Digital Solutions Corporation

Antoon Dekker

Johannes Leopoldus Bakx

Mats Oberg

Maarten Kuijper

Tony Petrus Van Endert

Charles Pandana

Stefan Geusens

Sumio Sekigawa

The present disclosure describes techniques for DVD-RAM header or land/groove detection. In some aspects, a wobble signal is integrated, an offset is removed from the integrated wobble signal, and a header is detected in the non-offset integrated wobble signal. In some aspects, a threshold value is adjusted based on a comparison of the received wobble signal and the threshold value, and a header is detected based on the adjusted threshold value.

DVD-RAM header or land/groove detection

An optical disk drive and a method for scanning an optical disk that includes a substantially circular track with a scanning velocity is provided. A servo control signal (SCS) is determined based on a servo error signal (SES). A first performance indicator (IND) of the servo actuator is determined from at least one of the SES and SCS. INDis compared against a first pre-determined threshold (ITHR), determining a first servo margin (MAR). The scanning velocity is set in dependence on at least MAR. In particular, scanning velocity is reduced when the first performance indicator exceeds the first pre-determined threshold. Additionally or alternatively, a bandwidth of control of the servo actuator can be adjusted in dependence on at least one of a second servo margin, determined from at least one of SES and SCS, and a third servo margin, associated with a mark quality determined from a central aperture signal.

Optical disk drive for scanning an optical disk with a scanning velocity and method for scanning an optical disk with a scanning velocity

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

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Eindhoven, Netherlands

Antoon Dekker