Eccentricity measurement method and eccentricity measurement device

Abstract

An eccentricity measurement method includes first to eighth steps. In the first step, an eccentricity measurement device for relatively linearly moving an optical image for measurement to an optical unit under test and acquiring an image on an observed surface orthogonal to a reference axis defined by a relative movement trajectory of the optical image is provided. In the second step, a position of a reference point is identified. In the third step, an optical unit under test is arranged. In the fourth step, the optical image is projected onto a projection position on the reference axis and a reflected image reflected on the surface under test is formed at an observation position where a distance from the projection position is a set value L. In the fifth step, a measurement image is acquired. In the sixth step, an image of the reflected image is identified. In the seventh step, an amount of positional deviation of the image of the reflected image is measured. In the eighth step, an amount of eccentricity of the apparent spherical center of the surface under test is calculated.