Patent ID: 8913236
Filing Date: 2014-12-16
Classification: G01B,G01M

Abstract:
1. An optical measuring instrument for measuring aspheric surfaces, the optical measuring instrument comprising: an optical measuring arm including a detector that captures information regarding wavefront shape, and imaging optics incorporating a variable focusing optic that images subapertures of an aspheric surface onto the detector; and a multi-axis drive platform including first and second rotational axes that relatively moves the optical measuring arm with respect to the aspheric surface through a plurality of subaperture measurement positions, a first translational axis along which are maintained different centers of curvature associated with a predetermined local shape of the aspheric surface at a crossing point of the first and second rotational axes through the plurality of subaperture measurement positions, and a second translational axis along which are maintained the subapertures of the aspheric surface conjugate to the detector through the plurality of subaperture measurement positions, wherein the variable focusing optic maintains a focus of the focusing optic at the crossing point of the first and second rotational axes through the plurality of subaperture measurement positions.