Arrangement for measuring coordinates of one or more retroreflectors mounted on an object - has illumination unit, retroreflector(s) and detector unit positioned where position and/or shape of detected light spot varies with position of retroreflector.

: Hartrumpf, M.

Abstract
The arrangement has an illumination unit (6) from which light passes via a beam divider (3) to at least one retroreflector (4'). Light returned from the retroflector to the beam divider is separated from the illumination light path and is incident on a detector unit (5) with which the position of the detected light spot is determined. Light from the illumination unit forms a beam which illuminates a larger area on the object surface than the area of the one or more retroreflectors attached to the surface. The detector unit is positioned where the position and/or the shape of the detected light spot varies with the position of the retroreflector. ADVANTAGE - Enables simple, contactless measurement of one or more object points.