Patent ID: 8000194

Claim:
An optical disc apparatus that records or reproduces information by irradiating laser light onto an optical disc having a plurality of recording layers, through an object lens, the apparatus comprising: a write signal generator to generate a write signal for recording information on the optical disc; a laser diode to generate laser light in accordance with the write signal; and a controller, when the plurality of the recording layers of the optical disc mounted inside the optical disc apparatus include an unrecorded recording layer, to: cause a signal to be recorded in a test recording area of the unrecorded recording layer by changing a recording power level using an initial focus offset value; calculate a level of a recording power for focus offset adjustment in accordance with reproduction result of the signal recorded in the test recording area; cause a signal for the focus offset adjustment to be recorded into the test recording area with the recording power for focus offset adjustment; calculate and set a focus offset value for subsequent recording of information based on reproduction of the recorded signal for the focus offset adjustment; and control the write signal generator to generate the write signal; wherein the controller generates a variable focus offset value while reproducing a previously recorded signal for focus offset adjustment, then evaluate quality of the signal, and calculate the appropriate focus offset value based on the evaluation results obtained.