METHOD FOR CONTROLLING EXPOSURE OF A SOLIDIFIABLE MEDIUM USING A PULSED RADIATION SOURCE IN BUILDING A THREE-DIMENSIONAL OBJECT BY STEREOLITHOGRAPHY

PROBLEM TO BE SOLVED: To achieve a controlled exposure on a desired zone of a surface medium, in an apparatus for forming a three-dimensional object from a solidifiable meadium. SOLUTION: The invention relates to a method and apparatus for forming three-dimensional objects from a medium solidifiable when subjected to a beam of pulsed radiation, wherein the pulses of radiation are generated when the beam is directed to desired pulsing locations on a target surface of the medium. Preferred embodiments of the present invention include a pulsed laser assembly having a laser and a pulse generation circuit, a control computer, a plurality of mirrors and mirror encoders. The computer controls movements of the mirrors which guide the laser beam across the surface of the solidifiable medium. The pulsing of the laser beam is correlated to the position of the mirrors and thus, is not dependent upon time. Pulsing linked to position of beam placement allows repeated use in controlled condition of a pulsed beam for the formation of objects. COPYRIGHT: (C)2007,JPO&INPIT