| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that since a probe optical path is separated spatially from a reference optical path, when temperature distribution, refractive index distribution by fluctuation of air or the like or a mechanical vibration is generated, an optical path difference is fluctuated between both optical paths to generate a measurement error, in a displacement measuring device using optical interference. <P>SOLUTION: An optical axis of probe light and the optical axis of reference light are brought close up to a distance uninfluenced by a disturbance, and an object is irradiated with the probe light and a reference plane is irradiated with the reference light respectively, and each reflected light is allowed to interfere with each other, and displacement of the object is determined from generated interference light. <P>COPYRIGHT: (C)2012,JPO&INPIT |
