Mitutoyo Corporation

Yasushi Ueshima

Makoto Abbe

Naoyuki Taketomi

Sotomitsu Hara

Makoto Abe

Yutaka Tsuchida

Yoshikazu Arai

Yasushi Ishii

A shape measurement method for measuring a shape of an object to be measured, which has a substantially rotating symmetric shape, includes: placing an aperture having an opening larger than an outer shape of the object to be measured and the object to be measured on an optical axis; taking an image generated by light projected to the object to be measured, by using an image pickup unit; and calculating one cross-sectional shape of the object to be measured based on a light intensity distribution of the image taken by the image pickup unit.

Shape measurement method and shape measurement apparatus

An optical-axis deflection type laser interferometer includes a reference ball serving as a measurement reference, a retroreflecting means disposed at an object to be measured, a laser interferometer length measuring apparatus outputting a measurement value between the apparatus and the retroreflecting means, and a rotational mechanism that rotates a beam projected from the laser interferometer length measuring apparatus around the reference ball. The laser interferometer additionally includes a displacement gauge that measures an error caused by a relative motion between the reference ball and the laser interferometer length measuring apparatus, and a rectilinear movement mechanism that displaces these in a direction of an optical axis of a measurement beam with respect to the reference ball while maintaining a relative positional relationship between the laser interferometer length measuring apparatus and the displacement gauge. With this structure, calibrating the displacement gauge without preparing a special calibrating device becomes possible, thereby securing traceability thereby securing traceability.

Optical-axis deflection type laser interferometer, calibration method thereof, correcting method thereof, and measuring method thereof

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Tsukuba, Japan

Yasushi Ueshima