| 摘要 |
PROBLEM TO BE SOLVED: To improve measurement accuracy, in a measurement device utilizing evanescent waves for detecting the position of a dark line of an optical beam by a plurality of light-receiving elements, by reducing measurement errors due to the sensitivity characteristics of each light-receiving element. SOLUTION: A reference position is defined before the regular measurement. The distance from the reference position to the dark line position is found by multiplying the number of differential channels between the differential channel corresponding to the reference position and the differential channel where the dark line is detected by a dynamic range (detection width per differential channel). The position of the dark line is calculated, by calculating the distance from the reference position to the position of the dark line. COPYRIGHT: (C)2004,JPO
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