Abstract
An optical non-contacting probe which detects displacement, position and inclination of work surfaces, is introduced for three dimensional coordinate measuring machines. The probe uses two light beams which intersect at an angle at a point near a work surface. Images of the spots by the light beams are formed on an opto-electronic device by lenses. The positions of the spots and the distance between them, and those of the images depend on the distance from the point of beam intersection to the work surface and on the inclination of the surface. The optical device detects the positions and distance of the images and an electronic circuit converts the device output into a signal which represents the displacement, position or inclination of the surface. The probe has a cylindrical shape of length 175 mm and of diameter 52 mm and its working distance is 57 mm. Two built-in semiconductor lasers are used as light sources. Sandy, ground, lathed, milled and mirror surfaces are measured successfully. Linearity of ±30 μm length measurement ranges from ±0.2 to ±0.4 μm. The standard deviation of position measurement ranges from 0.04 to 0.20 μm. Resolution and linearity of angle measurement are about four degrees of arc.
