| 摘要 |
PURPOSE:To obtain the exact detection result of positional deviation and to definitely irradiating the transmission object by a light beam by correcting the detection result of positional deviation of a transmission light beam based on the detection result of the state where a receiving light beam is not received. CONSTITUTION:Based on a receiving light beam LA2 transmitted by a transmitter/receiver, an error signal detection means 68 detecting the amount of positional deviation for the transmitter/receiver corrects the detection result of the positional deviation for the transmission light beam based on the detection result of the state where the receiving light beam LA2 is not received. Then the irradiated position by the transmission light beam LA1 is corrected by irradiated position correcting means 56, 57, 59A, 60 and 61 based on the detection result of the positional deviation. Thus, the irradiated position by the transmission light beam LA1 can be exactly corrected and the transmitter/receiver can be securely irradiated by the applicable transmission light beam LA1 even when the transmission distance is long. |
