Development of a Deep-Hole Measuring System by Using Autocollimation Principle (3rd Report)

Abstract

The measuring system for evaluating the accuracy of a deep hole is developed by using the autocollimation principle. The system consists of a measuring unit and an optical system for light reception. The measuring unit comprises one laser diode, two mirrors, two quarter-wave plates, one polarizing beam splitter, and a feeler. The system detects the displacement of a feeler on the basis of the autocollimation principle. The optical system for light reception, which receives the laser beam irradiated from the laser diode in the measuring unit, comprises a plano-convex lens and a CCD camera. In this research, the measuring unit is manufactured for trial and its measuring accuracies are examined by using the basic experimental apparatus. As a result, the followings are clarified. The optimum values of the CCD image processing parameters are 60 in threshold and 250μs in exposure. The error of measurement by using the measuring unit is ±0.26 μm. Measurement error of its rotational angle is ±0.01°.