CONFOCAL-POINT TYPE THREE-DIMENSIONAL MEASURING APPARATUS AND HEIGHT MEASURING METHOD

摘要

PURPOSE: To measure an object that is immovable in an optical axis direction by preparing a means for varying optical path length that varies the optical path length based on the optical path of condensing lens or after, a calculator for calculating the height of the object to be measured, and a shifting means that shifts vertically the object the convergent position of illuminating light against the light axis. ;CONSTITUTION: The height of an object 1 to be measured in a light axis direction is calculated by a calculator 13 based on the characteristics of light reception quantity that is detected corresponding to a plurality of different optical path lengths by variable means 12a-12c for optical path length and the light reception quantity that corresponds to the optical path length set in advance. In addition, the object and convergent position of illuminating light are vertically shifted against light axis by convergent position shifting means 14-16, and the reflecting lights from the object 1 are collected by a condensing lens 4 for three-dimensional measurement. Further, the optical path length can vary through the optical path of image-forming lenses 5a-5c or after in the means 12a-12c, thus improving its resolution by n² times when the scale factor of the image-forming lens is set to n.;COPYRIGHT: (C)1995,JPO