| 摘要 |
<p>Scanning apparatus (40) includes a transmitter (44), which is configured to emit a beam comprising pulses of light, and a scanning mirror (46), which is configured to scan the beam over a scene. A receiver (48) is configured to receive the light reflected from the scene and to generate an output indicative of the pulses returned from the scene. A grating (82) is formed on an optical surface in the apparatus and is configured to diffract a portion of the beam at a predetermined angle, so as to cause the diffracted portion to be returned from the scanning mirror to the receiver. A controller (30) is coupled to process the output of the receiver so as to detect the diffracted portion and to monitor a scan of the mirror responsively thereto.</p> |
