Optical disc apparatus

An optical disc apparatus comprising:

• an optical pickup moving in a radial direction of the optical disc, emitting a light beam to the optical disc, receiving a reflected light from a data recording face of the optical disc, converting variation of intensity of the reflected light to electric signals and outputting the electric signals;
• a signal processor for generating intensity signals of the reflected light, focusing error signals and tracking error signals corresponding to the signals outputted from the optical pickup;
• a focusing servo controller for focusing the light beam emitted from the optical pickup on the data recording face of the optical disc corresponding to the focusing error signals outputted from the signal processor;
• a tracking servo controller for tracking the light beam on a data recording track on the optical disc corresponding to the tracking error signals outputted from the signal processor;
• and
• a main processor for controlling an initial reading operation so as to read out information data recorded in the innermost data recording area on the optical disc;
• wherein
• in the initial reading operation,
• the main processor senses periods between adjoining two pits formed on the optical disc from the electric signals outputted from the optical pickup, and judges whether the periods between the pits are normal or not while the light beam emitted from the optical pickup is focused on the data recording face of the optical disc by the focusing servo controller;
• when the periods between the pits are normal, the main processor controls the tracking servo controller so as to track the light beam precisely on the present data recording track, and reproduces the information data from the electric signals outputted from the optical pickup;
• alternatively, when the periods between the pits are abnormal, the main processor senses the periods between the pits and judges whether the periods between the pits become normal or not while the optical pickup is moved inwardly and the light beam is focused on the data recording face of the optical disc;
• and
• when the periods of the pits become normal, the main processor controls the tracking servo controller so as to track the light beam precisely on the present data recording track, and reproduces the information data from the electric signals outputted from the optical pickup.

A method for reading out information data from an optical disc in an optical disc apparatus comprising the steps of:

• placing an optical pickup at an initial reading position outwardly distant a predetermined distance from the innermost edge of an innermost data recording area on the optical disc;
• sensing periods between adjoining two pits formed on the optical disc based on electric signals outputted from the optical disc while a light beam emitted from the optical pickup is focused on a data recording face of the optical disc, and comparing the periods between the pits with a standard value;
• when the periods between the pits are equal to or smaller than the standard value, tracking the light beam precisely on a data recording track facing the initial reading position, and reproducing the information data based on the electric signals obtained from the pits sensed on the data recording track;
• alternatively, when the periods between the pits are larger than the standard value, moving the optical pickup inwardly from the initial reading position, and sensing periods between the pits formed on the optical disc based on the electric signals outputted from the optical pickup while the optical pickup is moved and the light beam is focused on the data recording face of the optical disc, and comparing the periods between the pits with the standard value;
• and
• when the periods of the pits become equal to or smaller than the standard value, tracking the light beam precisely on the data recording track, and reproducing the information data based on the electric signals obtained from the pits sensed on the data recording track.