Laser scanning apparatus with function monitoring

摘要

The electronic equipment incorporates a transmit-receive device (10) with a pulsed laser. It is connected to an evaluation circuit (14). The laser beam (12) is reflected from a scanning mirror (16), rotating about an axis (18) at right-angles to the mirror. The reflected beam passes through an inclined window (20) with a diffraction grating or semitransparent mirror (22) to divert part of the beam (24) to a photocell (28). The output from the photocell (30) is fed back to the evaluation circuit.