LIGHT BEAM PATH SWITCHING DEVICE

摘要

PURPOSE:To provide the light beam path switching device having a fail-safe mechanism which enables positioning even if a positioning mechanism is faulty. CONSTITUTION:A position which adjacent to a movement target position is regarded as a speed reduction start point, and an LED 3 which is provided corresponding to a fixed-side connector 13 is turned ON; and a photodetection part 16 which is provided on a moving-side connector side detects its light and reduces a moving speed; and an LED at a movement target position is turned ON and the photodetection part 16 detects its light to perform positioning operation. If an LED gets out of order, the photodetection part 16 or overrun limit switches 17 and 18 detect the fault. Once the fault is detected, an LED nearby the faulty LED is turned ON, a specific photodetecting element among plural photodetecting elements in the photodetection part 16 is selected, and the illuminating LED is detected to perform speed reduction and positioning operation.