| 摘要 |
PROBLEM TO BE SOLVED: To obtain an interference spectrophotometer in which a sampling signal at a set cycle is generated from laser interference fringes. SOLUTION: A sine wave-shaped interference-fringes signal (a positive-phase signal) is inverted by an inverting amplifier 12, and a negative-phase signal is generated so as to be input to a comparator 13 and a comparator 14 in parallel with the positive-phase signal. The comparators 13, 14 compare an amplitude at an identical reference voltage, and they convert the positive-phase signal and the negative-phase signal into respective binary signals. An edge detection part 15 and an edge detection part 18 detect the rise edge of the binary signals in two systems, and pulsed signals in a prescribed width are generated so as to be given, as sampling signals, to an S/H circuit 17 and an S/H circuit 18 which are installed in parallel. Thereby, the influence of the difference in a through rate between the rise and the fall of the comparators 13, 14 is eliminated, and a sampling operation can be performed precisely at a rate which is twice that of interference fringes.
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