Displacement detecting device

摘要

A displacement detecting device includes a non-contact sensor (100A) having a light source (102), an objective lens (114) focusing output light from the light source (102) onto a measurement surface (TG), and a light receiving element (120) detecting displacement information based on a focal length of the objective lens (114) by using reflected light from the measurement surface (TG); a control unit (200) adjusting the focal length based on the displacement information; a displacement-amount measuring unit (400) having a linear scale (408) attached to the objective lens (114) with a link member (500) therebetween and measuring an amount of displacement of the linear scale (408) when the focal length is adjusted. A light adjustment member (130A) is disposed between the light source (102) and the objective lens (114) or between the objective lens (114) and the light receiving element (120) and has an aperture section transmitting the output and/or reflected light therethrough and a light blocking section that blocks a specific light component of the output and/or reflected light.