Near-field gap pull-in method and optical disc apparatus therefor

An optical disc apparatus, comprising:

• a condenser to focus light radiated from a light source onto a disc and to receive light returned from the disc;
• an actuator to raise or lower the condenser vertically with respect to the disc based on an actuator driving voltage;
• a light amount detector to detect an amount of light returned from the disc through the condenser;
• a servo module to generate the actuator driving voltage and a gap error signal based on the light amount detected by the light amount detector;
• and
• a control module to obtain the range of the actuator driving voltage during a period of time where the decrease rate of the gap error signal is constant based on the gap error signal and the actuator driving voltage generated by the servo module, when light focused on the disc is near-field light, and to control the servo module such that gap pull-in is performed on the disc during a period of time where the actuator driving voltage value provided from the servo module is within the obtained range.

A computer-readable recording medium storing a program to execute a gap pull-in method, the gap pull-in method comprising:

• determining whether light focused on a disc as an actuator ascends is near-field light using a gap error signal;
• obtaining a range of an actuator driving voltage value during a period of time when the decrease rate of the gap error signal is constant, when the light focused on the disc is near-field light;
• and
• performing gap pull-in on the disc during a period of time when the actuator driving voltage value is within the obtained range.

A recording and/or reproducing apparatus to record data to or read data from an optical disc, the apparatus comprising:

• an optical pickup to focus light onto the optical disc and to receive light reflected from the optical disc so as to record data on the optical disc and/or reproduce data from the optical disc;
• a servo module to generate an actuator driving voltage and a gap error signal based on an amount of light received by the optical pickup, and to control the raising or lowering of the optical pickup based on the actuator driving voltage;
• and
• a control unit to determine a range of the actuator driving voltage during a period of time where a rate of change of the gap error signal is a constant negative value and the light focused on the optical disc is near-field light, based on the gap error signal and the actuator driving voltage, and to control the servo module to perform gap pull-in on the optical disc during a period of time where the actuator driving voltage is within the determined range.