| 摘要 |
PURPOSE:To make it possible to accurately perform the sampling of an infrared interference optical signal corresponding to the position of a moving mirror during a time when the moving mirror moves many times, by measuring a time interval from the generation of a trigger signal showing that the moving mirror reached a specific state to that of the sampling signal succeeding thereto. CONSTITUTION:When a moving mirror 5 is moved to the right direction, infrared interference rays, laser interference beam and white interference light are respectively obtained from a detectors 8, 11, 16. The interference rays from the detector 16 are supplied to a trigger pulse generation circuit 23 having a reference level preset thereto and, when said interference rays came to reference level intensity, a trigger pulse is generated. The signal from the detector 11 receives wave form shaping by a wave form shaping circuit 21 to obtain a pulse signal. The trigger pulse signal is supplied to a counter 25 where the counting of the signal from a clock signal generation circuit 24 is started. The counting of the signal in the counter 25 is performed up to the point of time when the pulse from the wave form shaping circuit 21 succeeding to the trigger pulse is generated and the delay time corresponding to each value of the time up to generation is stored in a computer 19. |
