| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to detect deterioration of a semiconductor laser in a short time with high accuracy without adding a circuit unit for measurement to an optical disk player and without being influenced by irregularities and environmental temperatures of optical pickups and optical disks.SOLUTION: An optical disk player includes a laser controller that can control an output light quantity of a semiconductor laser by an APC reference voltage, measures amplitudes FEL1, FEL2, and FEL3 as output light quantities of the semiconductor laser in respective stages by changing the APC reference voltage to a plurality of stages of APC reference voltages REF1, REF2, and REF3, determines efficiency that is a ratio of the APC reference voltage to the output light quantity in each stage, further determines an efficiency rate that is a rate of efficiency in the plurality of stages, and compares the efficiency rate with a predetermined value, thereby detecting whether the semiconductor laser deteriorates. |
