PROCESS AND DEVICE FOR TAKING A DISTANCE IMAGE

摘要

The process for taking a distance image on the active triangulation principle using a laser scanner which scans an object space in steps and a CCD camera accepting the light reflexes as video images and a computer which reads the latter's image information and processes it makes use of a wedge-shaped laser beam and an intermediate storage of the video images within a distance image with the subsequent subtraction of the previous from the current video image. Stray light is thus effectively suppressed. In the relevant device, the wedge-shaped laser beam is generated by means of a first set of cylindrical lenses with overcompensation of the aperture error. The camera object lens used is numerically optimised in such a way that all the bunches of light form a sufficiently narrow angle to the optical axis in a region in which an interference filter is fitted. This ensures a uniform distribution of brightness over the entire width of the wedge and the elimination of stray light.