| 摘要 |
PURPOSE:To measure dimensions accurately, by memorizing a digital signal with the processing of a distribution of quantity of light obtained by scanning with a photoelectric conversion unit to calculate the gap dimensions based on the coordinates of the minimum and maximum of the digital signal determined with a signal processor. CONSTITUTION:A fine gap 18 formed on an object to be measured is expanded with an optical microscope and a photoelectric conversion unit 31 is made to scan over the expanded image to obtain a distribution of quantity of light, from which dimensions of a gap 18 are measured. In such a measurement of fine dimensions, the minimum at the bottom and the maximum at the top are determined in the differentiation signal 38 of the distribution of quantity of light obtained with an amplifier 33, a low-pass filter 35, a differentiation circuit 36 and the like as means for time differentiation of the distribution of quantity of light obtained with the scanning of the photoelectric conversion unit 31 and the like and a means for conversion into time distance differentiation using a length measuring linear gauge 30 running synchronizing the scanning with the photoelectric conversion unit 31 to calculate the fine dimensions 3 of the gap 18 from both the values of the minimum and maximum thus obtained. |
