| 摘要 |
<P>PROBLEM TO BE SOLVED: To correctly detect signal light even when incident light is extremely intense. <P>SOLUTION: An optical separator 62 separates reflected light pulses, and a PD 64 detects one of the separated reflected light pulses. When a detected signal from the PD 64 is equal to or higher than a threshold value, an operation control circuit 70 operates an optical adjustment device 68 to shut off light. On the other hand, when the other of the separated reflected light pulses passes through a delay mechanism 66, and enters the optical adjustment device 68 when the optical adjustment device 68 operates. <P>COPYRIGHT: (C)2012,JPO&INPIT |
