Asphere measurement method and apparatus

摘要

Disclosed is an asphere measurement method capable of measuring the surface deviations and the surface tilts with high accuracy even when an asphere to be measured does not have the wedge-shaped flat portion. An optical interferometer using a first interferometer (1A) and a second interferometer (1B) acquires shape data of the center portions of a first lens surface (91) and a second lens surface 92 of an aspheric lens (9). From the respective shape data, respective position data of a first umbilical point P 1 , a first center of curvature, and a first axis of the first lens surface (91) are acquired in a first measurement coordinate system. Simultaneously, respective position data of a second umbilical point P 2 , a second center of curvature, and a second axis of the second lens surface (92) are acquired in a second measurement coordinate system. On the basis of these position data and the relative position relation between the first measurement coordinate system and the second measurement coordinate system, surface deviations and surface tilts of the aspheric lens (9) are acquired.