| 摘要 |
<p>The method involves sending light from a transmitter (30) i.e. LED, along a sending light system axis (32) in a monitoring area (10). Reflected lights (36, 38) from the area are detected by two light receivers (44, 50) over two receiving light paths, respectively. The receiving light paths are provided on different sides of the axis. One of the receivers has two spatial detection zones (46, 48) arranged such that one of the zones receive the reflected lights when a diffuse reflecting object is provided in a scanning region (12) and a background region (14) of the area, respectively. An independent claim is also included for a light scanner comprising a light transmitter.</p> |
