| 摘要 |
PURPOSE:To easily control the quantity of transmitted light of light pulses by rotating a disk which has specific opening parts across the optical path of light pulses synchronously with light pulses of pulse oscillation laser light. CONSTITUTION:The rotating shutter disk 1 is provided with light transmission windows 2-4 whose area ratio is, for example, 4:2:1. On the other hand, light 7 from a light emitting diode 6 is made parallel to a shaft 10 and light incident on a photodetecting element 8 through an opening part of the shutter is detected, so that a controller 9 controls the rotation of the rotating shaft 10, therefore, the shutter disk 1 on the basis of the photodetection output. The rotation of the shutter disk 1 is synchronized to the light emission timing of pulses of the laser light 5. Consequently, the quantity of light is adjusted easily and accurately. |
