Patent ID: 7633840
Filing Date: 2009-12-15
Classification: G11B

Abstract:
1. An apparatus comprising: a focus controller configured to control a lens in relation to a laser beam and allow said laser beam to focus on a disc; a photo-diode sensor configured to generate one or more photo-diode signals in response to said laser beam; a data circuit configured to generate disc status signals in response to said one or more photo-diode signals; a focus error creation circuit to generate a focus error signal, wherein said focus error signal provides a first value based on a focus point of said laser beam; and a focus offset circuit configured to offset said first value of said focus error signal to a second value to allow said focus controller to move said lens to a position which will increase the focus point of said laser beam on said disc, wherein (i) said disc status signals comprise one or more of a data signal and a beam push-pull signal, (ii) in a first mode, the focus offset signal is generated in response to said data signal, and (iii) in a second mode the focus offset signal is generated in response to said beam push-pull signal.