| 摘要 |
A high speed scanning system for scanning a moving target. Comprising rotating a polygonal mirror with a plurality of mirrored sides about an axis of rotation at the center thereof directing a first laser beam at the polygonal mirror along a first path intersecting one mirror face at a time and reflecting at a given useful angle to scan a target moving in at least one direction with a first scan by each mirror face in one scan direction, wherein an imaginary line extending the first path beyond the intersected mirror face is offset from the axis of rotation. A second laser beam is directed at the polygonal mirror along a second path intersecting the same one mirror face at a time as the first beam and reflecting at said given useful angle to scan and the moving target with a second scan in the one scan direction delayed in time from the first scan by each mirror face, wherein an imaginary line extending the second path beyond the intersected mirror face is offset from the axis of rotation and wherein the second path forms an angle with respect to the first path which is greater than said given useful angle, whereby two scans are effected for each mirror face. The laser beam light directed at the moving target is then detected.
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