| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive measuring apparatus capable of precisely measuring an absolute position. Ž<P>SOLUTION: This measuring apparatus 100 includes a first light source 1 for radiating a first light beam, a second light source 2 for radiating a second light beam whose coherency is lower than that of the first light beam, a first beam splitter 3 for superposing the second light beam to the first light beam, a second beam splitter 4 for splitting radiation light radiated from the first beam splitter into measurement light and reference light, an interference measuring device 8 for detecting an interference signal by synthesizing the reference light with reflection light of the measurement light, and a signal processing device 20 for processing a signal output from the interference measuring device. Wavelengths of the first light beam and the second light beam are set to be the same. The signal processing device 20 includes signal intensity measuring sections 14-1, 14-2 for measuring an intensity of an interference signal obtained from the second light source 2 and an origin determining section 16 that determines that a maximum point of the intensity of the interference signal obtained from the second light source 2 is an origin point. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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