Optical disc apparatus

An optical disc apparatus comprising an optical pickup, wherein

• the optical pickup further comprises:
• a laser diode for emitting a laser beam to an optical disc;
• an objective lens for focusing the laser beam emitted from the laser diode on a data recording face of an optical disc;
• a photo-detector for receiving reflected beam reflected from the optical disc and for converting light signals of the reflected beam to electric signals;
• a lens holder for holding the objective lens;
• a guide shaft engaged with a bearing of the lens holder for pivoting the lens holder in a manner so that the lens holder can be slid in a direction in parallel with an optical axis of the objective lens and reciprocally swung in a direction perpendicular to the optical axis;
• a focusing servo mechanism for moving the lens holder in the direction in parallel with the optical axis including at least a focusing coil, a yoke and a permanent magnets;
• a tracking servo mechanism for moving the lens holder in the direction perpendicular to the optical axis including at least a tracking coil, a yoke and a permanent magnet;
• and
• a wobble signal of triangular waveform having a predetermined voltage and a predetermined frequency is applied to the tracking coil for displacing the lens holder repeatedly in the direction perpendicular to the optical axis of the objective lens around the guide shaft, while the lens holder is moved in the direction in parallel with the optical axis for focusing the laser beam on the data recording face on the optical disc by driving the focusing coin in a focusing on operation.