Patent ID: 6556525
Filing Date: 2003-04-29
Classification: G11B

Abstract:
A disk drive apparatus, comprising:information writing/reading means for recording or reproducing information by irradiating laser beams onto a signal plane of a disk-shaped recording medium; unrecorded area detecting means for detecting unrecorded areas on said signal plane, based on the results of comparing reproduction signal levels from said information writing/reading means with a predetermined threshold; and threshold adjusting means for executing adjustment actions for setting said threshold; said threshold adjusting means comprising: action control means for controlling said information writing/reading means so that a reproducing action is performed regarding a certain adjusting area which is an unrecorded area; threshold varying means for changing the adjustment threshold at the time of performing reproducing actions regarding said adjusting area; andthreshold determining means for making comparison for each changed adjustment threshold with reproduction signal levels, and determining said threshold based on the comparison results.