Length and angles optical measurement system - may also measure optical constants, based on moire or interference strips

摘要

The apparatus consists of a photoelectric receiver system (17-20) which is fitted with centrosymmetrical or centre oriented receiving surfaces; it is so arranged, that straight lines passing through centres of gravity of these surfaces and running parallel to the image plane and to the Moire or interference strips are arranged in pairs which are spaced by equal distances. There is an extended transparent plate (10) on which are ruled a large number of vertical lines, and in front of this there is a square plate (11) with similar lines. The plate may be tilted through a small angle by moving a lever (14) so that the two sets of lines are at a small angle and a moire pattern is produced.