US Patent 10012831 Optical monitoring of scan parameters

Scanning apparatus includes a transmitter, which is configured to emit a beam comprising pulses of light, and a scanner, which is configured to scan the beam along a scan axis over a specified angular range. A scattering line extends across a path of the scanned beam. A receiver is configured to receive the light scattered from the scattering line and to generate an output indicative of an intensity of the scattered light. A controller is coupled to process the output of the receiver so as to monitor operation of the scanner.