| 摘要 |
An apparatus for rapidly varying the spot size of a scanned imaging laser beam comprises a focusing device (e.g. focussing and collimating lens arrangement) and a beam displacement control device (e.g. a rotary actuator scanner mirror or linear actuator). The beam displacement control device is operative to cause relative displacement between the laser beam and a selected one of a plurality of reflector element positions. Respective ones of the plurality of reflector positions are located at respectively different separation distances from the focusing device. As a result, in the course of traveling along an laser beam path, the laser beam is incident upon the focusing device and the reflector element, so as to be directed to a given spatial location along the path, whereby the laser beam has a resultant beam width that is dependent upon the separation distance between the selected reflector element position and the focusing device. |
