Single beam radial tracking method for optical discs

Abstract

An apparatus and a method for reducing an offset error in a position of an objective lens of an optical disk reader by using a single beam push-pull signal. The apparatus includes a radial actuator that is configured to control the position of the objective lens. A controller that receives a push-pull signal that corresponds to the offset error of the objective lens and estimates the offset based on the push-pull signal. A sine generator generates a sine wave based on the estimated offset and further generates a feedback signal based on the sine wave to drive the radial actuator to reduce the offset error in the position of the objective lens. The apparatus also includes a data detector that is utilized to change the tracking method of the optical disk reader to a differential phase detection method upon detecting data in a data spire of the optical disk.

Dependencies are inferred from the claim text.