Optical displacement meter

An optical displacement meter of a light sectioning method which measures a profile of an X-Z cross section of a measuring object conveyed in a Y direction based on a principle of triangulation, the optical displacement meter comprising:

• a light projecting section that scans slit light or spot light having a width in an X direction to irradiate the measuring object;
• an image sensor that receives reflected light from the measuring object, the image sensor having a plurality of pixels two-dimensionally arranged in a U direction corresponding to the X direction and a V direction corresponding to a Z direction, and outputting a light receiving amount of the reflected light by the plurality of pixels;
• a detecting unit that detects, as a peak position, a position of a pixel in the V direction that is a peak of the light receiving amount for each of a plurality of pixel rows arranged in the U direction;
• a measuring unit that acquires, from each position of the plurality of pixel rows in the U direction and the peak position in the V direction, a plurality of profiles of the X-Z cross section at different positions in the Y direction, and measures a three-dimensional shape of the measuring object based on the acquired plurality of profiles;
• and
• a determining unit that determines, based on whether a profile exists in a blind spot region in which it is impossible to measure a height which occurs in a Y-Z cross section corresponding to an angle formed between a light projecting axis of the light projecting section and a light receiving axis of the image sensor based on the principle of triangulation, a part of the three-dimensional shape generated by the measuring unit as an erroneous detection value.