Measurement of aspheric surfaces with 3D-Deflectometry

For the production of aspheric surfaces testing devices which provide fast and accurate measurements of the surface topography are badly needed. 3D-Deflectometry has demonstrated its capability of meeting these demands and we will present a first functional model of an aspheres deflectometer. Using a high resolution two-dimensional angle sensor the deflectometer determines the local slopes of an aspheric surface. The sensor scans the surface in spherical coordinates thus measuring the deviation from a reference sphere. A new fault tolerant software algorithm transfers slope information into surface topography data while simultaneously correcting for systematic errors of the instrument setup. We are going to present the design and first measurement results of the new aspheres deflectometer.