Patent ID: 6268923
Filing Date: 2001-07-31
Classification: G01B,H04N

Abstract:
An optical method for measuring three-dimensional surface topography of an object having a surface contour, the method comprising:projecting a predetermined pattern of light on a surface of the object to generate a corresponding reflected light signal;generating a plurality of images from the reflected light signal in a plurality of separate but optically coincident detector planes of detectors, each of the detectors having a gain and an offset and wherein each of the images includes a fringe pattern thereon having a known phase shift different from each of the other phase shifts;determining relative offset and gain differences of the detectors;compensating for the gain and offset of at least one of the detectors based on the offset and gain differences;measuring radiant energy in the images in the plurality of detector planes to produce a plurality of signals; andprocessing the plurality of signals to obtain a surface contour map of the object.