Optical precision angle measuring method - using photosensors controlled by rotary laser to control reference and measuring counters

摘要

An angle measuring device has a housing (1) enclosing a laser (6) and a rotary mirror (2) which deflects the laser beam (7) about a given axis for rotation past a measuring window (8). The laser beam is detected by a photodiode (9) at the beginning of the measuring window to provide a signal for a reference timer (14) and activate a measuring timer (15). The latter is subsequently stopped by a measuring photodiode (13) incorporated in a sensor (12) brought into contact with a measured object (11). The angle (beta) between the lines extending from the rotational axis (3) and each of the two photosensors (9,13) is calculated from the count values contained within the reference and measuring times (14,15). ADVANTAGE - Measurements are not effected by surface roughness or temp. variations.