Moire interferometry system and method with extended imaging depth

摘要

A moire interferometry system and method are provided for achieving full field surface contouring with an extended depth of view of image. The moire interferometry system includes a projection system generally made up of a light source, imaging lens and a square wave grating pattern. The imaging lens is configured to filter higher order light rays passing through the square wave grating pattern so as to project a sine wave like pattern onto a desired surface. The moire interferometry system also includes a viewing system generally made up of an imaging lens, a submaster grating and a camera. The submaster grating is preferably a customized grating that may be produced by recording a grating pattern in relation to a reference surface. The camera is able to view an image anywhere within the extended depth of image and analyze the moire fringes. A determination of deviation between a test part and a reference surface provides a part inspection system.