Optical surface proximity measuring device and its application to the plotting of the profile of a surface

摘要

The invention relates to an optical device for measuring the surface proximity and to its application in the plotting of a profile. The device comprises a radiation emitter forming a light spot on the surface and two detectors, which are sensitive to the light flux reflected by the surface. A pair of focusing elements having different focal lengths are associated with the detectors. The ratio between the signals supplied by the detectors is determined by a processing circuit. This ratio is used to calculate the distance independently of the angle of incidence of the incident beam and the reflection coefficient of the surface.