| 摘要 |
A system for forming optical beam spots of different sizes on an imaging surface, includes an emitter configured to emit an optical beam along a path. The optical beam is focused at a first focus point and impinges upon the imaging surface downstream of the first focus point. A lens, having a single fixed magnification other than one, is located between the first focus point and the imaging surface so as to be in the optical path of the optical beam. The lens is moveable between a first position located a first distance from the first focus point and a second distance from a second focus point of the optical beam which is downstream of the lens and a second position located the second distance from the first focus point and the first distance from the second focus point. With the lens at the first position the optical beam forms a beam spot of a first size on the imaging surface and with the lens at the second position the optical beam forms a beam spot of a second size, which is different than the first beam size, on the imaging surface.
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