| 摘要 |
PROBLEM TO BE SOLVED: To detect an accurate and stable rate of reflected light when a recording medium is irradiated with plural beam spots different in light quantity. SOLUTION: The main beam signals S1 and the sub-beam signals S2 which are outputted from a PUM 1 are added together by adder circuits 4 and 5 and the main total and sub-total signals S3 and S4 are outputted respectively. Then the signals S3 and S4 are added together by an adder circuit 6 and a main/sub-total signal 5 is outputted, and the reflection factor detection signals of signals S3 and S5 are inputted to a CPU 3. The CPU 3 uses the reflection factor detection signal of the signal S3 in an off-focus mode and uses the reflection factor detection signal of the signal S5 when an off-track state is recognized in an on-focus mode. |
