Patent ID: 9741122
Date: 2017-08-22
CPC Classifications: G01B,G02B,G06K,G06T

Claim:
1. A method for determining the distance between two optical boundary surfaces spaced apart from each other in a first direction, the method comprising: a) imaging a pattern into a plane transverse to the first direction and acquiring an image of the pattern imaged in the plane; b) repeating step a) for a plurality of different positions in the first direction, wherein the different positions cover an area in the first direction in which the two optical boundary surfaces lie; c) ascertaining a first image from the images from step a), wherein the plane into which the pattern acquired with the first image was imaged either coincides with a first of the two optical boundary surfaces or has the smallest distance to the first optical boundary surface in the first direction in comparison with the planes in which the pattern acquired with the other images from step a) was imaged; c1) determining the position of the first image in the first direction; d) ascertaining a second image from the images from step a), wherein the plane into which the pattern acquired with the second image was imaged either coincides with a second of the two optical boundary surfaces or has the smallest distance to the second optical boundary surface in the first direction in comparison with the planes in which the pattern acquired with the other images from step a) was imaged; d1) determining the position of the second image in the first direction; and e) calculating the distance based upon the determined positions of the first and second image.