US Patent 7298680 Optical disc apparatus

An optical disc apparatus provided with an automatic power control circuit which controls power of laser light by obtaining a difference between a value detected by a front monitor 6 and a target value individually for reproduction power and for recording power includes: a detector 7 for detecting light reflected from an optical disc, a sample-hold circuit 26 which performs on an output of the detector 7 a sample-hold operation at the timing of the reproduction power; and a microcomputer 29 which computes a reference value from the reflected light of the reproduction power at the timing just before the start of a recording operation after receiving a recording command until opening of a recording gate, and at the time of recording operation an intensity of reflected light on which a sample-hold operation is performed is compared with the reference value to correct a target value of the reproduction power.