METHOD AND DEVICE FOR MEASURING THICKNESS OF TEST OBJECT

摘要

PURPOSE: A method and device for measuring thickness of test object are provided to instantaneously measure thickness by simple structure where a wedge prism is placed on an optical path. CONSTITUTION: A device includes a screen; a pattern generating device projecting a light pattern with bright parts and dark parts periodically repeated; and a measuring device measuring thickness of a test object using phase difference between a pattern not penetrating the test object and a pattern penetrating the test object when the test object transparent to light and having double refraction is inserted into an optical path of the patterns.