Patent ID: 7187631
Filing Date: 2007-03-06
Classification: G11B

Abstract:
1. A disc apparatus, comprising: an emitter for emitting a laser beam; a lens for irradiating the laser beam emitted by said emitter onto a recording surface of a disc recording medium; a first detector for detecting a first signal based on the laser beam reflected from said recording surface; an actuator for actuating said lens in each of a plurality of positions assigned in a direction perpendicular to said recording surface; a determiner for determining whether or not amplitude of the first signal detected by said first detector corresponding to the position of said lens actuated by said actuator is below a threshold value; a setter for setting to said emitter a laser power in which said determiner determines that the amplitude of the first signal is below the threshold value with respect to every position actuated by said actuator; a second detector for detecting, from among the plurality of positions noted by said actuator, a position at which the amplitude of the first signal detected by said first detector corresponding to the laser power set by said setter is maximum; a controller for controlling a position of said lens based on the first signal detected by said first detector after a setting operation of said setter is completed and the position detected by said second detector; and a reproducer for reproducing a second signal based on the laser beam reflected from said recording surface after start of a controlling operation of said controller.