Patent ID: 7164639

Claim:
A tilt control method for controlling the tilt, with respect to an optical disc, of an objective lens in an optical pickup for recording or playing back signals through the objective lens, comprising: a tilt control circuit for controlling the tilt of said objective lens by controlling the amount of current to a tilt adjustment coil; and a focusing control circuit for adjusting the focus of the objective lens by controlling the current to a focusing coil; a preprocessing procedure comprising the steps of: detecting, at least at two different positions along a radical direction on the optical disc during recording or playback of signals to or from said optical disc, a DC voltage value from a focusing drive signal that is supplied to said focusing coil; and obtaining from respective detected DC voltage values a relationship between a position on said optical disc where recording or playback is being performed and the DC voltage value of said focusing drive signal; actual recording or playback procedure comprising the steps of: detecting a recording or playback position to obtain a corresponding DC voltage value during recording or playback of signals to or from said optical disc; and controlling the amount of current that is supplied to said tilt adjustment coil on the basis of a signal in which the obtained DC voltage value is added to an AC signal included in the drive signal that is supplied to said focusing coil at the time.