3D shape sensing using a phase mask to extend the depth measuringrange

摘要

An approach using a phase mask to enlarge the depth measuring range for a 3D shape sensing system is presented. A microscope combined with a wide-angle eyepiece lens is employed to project a fringe pattern onto the inspected surface. A CCD camera observes the projected fringes through another microscope with a phase mask. The phase mask enlarges the depth of field of the image acquisition system, while the wide-angle eyepiece lens increases the depth of focus of the fringe projection system. It is found that the depth measuring range has been extended up to 1600-micron, even though the depth of field of the image acquisition system is only 80-micron.