Surface profile measurement of concave-shaped mirror using grating projection method

摘要

Specular objects with large shape-change such as the concave-shaped mirror are used in the several industrial fields. However, concave-shaped mirror is difficult to measure the surface profile with non-contact method. In this paper, we describe the profile measurement method for concave-shaped mirror such as an ellipsoidal mirror and an aspherical mirror. This measurement method, based on the grating projection method, employed two cylinder-type gratings with different radius; measurement time is shorter than that of contact-method. The surface of ellipsoidal mirror, one of the concave-shaped mirrors, is measured and repeatability accuracy is evaluated.