| 摘要 |
PROBLEM TO BE SOLVED: To measure a displacement speedily and precisely for an object to be measured having various surface states. SOLUTION: A displacement sensor is equipped with a confocal optical system for moving an objective lens 6 along an optical axis, wherein incident light from a laser diode 1 is transformed into a slit beam by a cylindrical lens 4, and its portion on the Y-axis side perpendicular to the optical axis is narrowed and condensed on a surface of the object to be measured 90, and its portion on the X-axis side perpendicular to the optical axis is made incident in an expanded fashion in order to average reflection light components from the surface. The reflection light from the surface of the object to be measured 90 is received by a photodiode 2 through an aperture 5a disposed on a conjugate position of the laser diode 1. The aperture 5a is a slit in a shape having a short Y-axis and a long X-axis. The displacement of the surface is measured based on the position of the objective lens 6 where the reception signal shows a peak. COPYRIGHT: (C)2010,JPO&INPIT
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