Device for scanning the contour of a surface of a workpiece

Abstract

Device for the contact-free measurement of a distance from a surface, particularly for scanning the contour of a surface of a workpiece along a given measuring path, comprising a measuring body enclosing optoelectronic means for transmitting light to the surface to be measured and converting the light reflected by such surface into an electrical signal as a function of the distance from the surface. The measuring body is supported on a stand and is movable in the direction of measurement. The optoelectronic means comprise a focus position measuring system and an optoelectronic position scanning unit for scanning the position of the measuring body relative to the supporting stand. An adder connected to indicating or recording means adds the output signal of the focus position measuring system to the output signal of the position scanning unit to produce a summation signal which corresponds to the distance of the measuring body from the surface being measured at any selected point of movement of the measuring body on the supporting stand. Thus, the measured value is additively formed of two partial values, of which the partial value derived from the focus position measuring system is obtained without sluggishness, while the other partial value permits the measurement of a coarse profile.