Patent ID: 7177253

Claim:
An optical disc drive comprising: a laser light source for emitting a laser beam of which the intensity is changeable with the amount of drive current supplied thereto; a first photodetector, which receives a portion of the laser beam that has been emitted from the laser light source and then reflected from an optical disc, thereby generating a readout signal; a second photodetector, which receives another portion of the laser beam that has been emitted from the laser light source, generates an electric signal of which the level represents the power of the laser beam received, and outputs the electric signal as a light quantity detection signal; and a feedback control loop, which compares the level of the light quantity detection signal with a predetermined target value and controls the amount of the drive current so that the level of the light quantity detection signal approaches the target value, wherein in reading data from the optical disc, the target value is changed so as to compensate for a variation of the sensitivity of the second photodetector, thereby controlling the power of the laser beam emitted from the laser light source, said variation of the sensitivity of the second photodetector being detected when a write power optimization is conducted.