Device to identify relative position of sample to be tested

摘要

The device has a light source (21) and optical elements (22,23), with which two beams (27a,27b) are deflectable on the surface of a sample (1) to be tested. Two position-responsive detectors are provided, which measure the light reflected from the sample surface. The first detector (24) is provided to measure the amount of tilting of the sample. The second detector (25) is provided to measure the sample distance.