Abstract: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for producing three-dimensional objects by selectively subjecting a liquid or other fluid-like material to a beam of prescribed stimulation. In a preferred embodiment a source of prescribed stimulation is controlled to reduce or inhibit the production of the prescribed stimulation during at least some periods when the prescribed stimulation is not needed to expose the material. In another preferred embodiment, the source of stimulation is controlled to vary the quantity of prescribed stimulation that is produced and allowed to reach the material. In an additional preferred embodiment, control of laser output occurs based on a combination of supplying a regulated amount of voltage to an AOM in conjunction with temporary sensing of laser power and a known desired power to attain.

Abstract: Methods 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 made to occur when the beam is directed to desired pulsing locations on a target surface of the medium. Preferred embodiments of the instant invention include a pulsed laser assembly, including a laser and a pulse generation circuit, a control computer, a plurality of mirrors and mirror encoders. The computer controls the movement 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 controlled and repeatable use of a pulsed beam for the formation of objects.

Abstract: A method and apparatus for building three-dimensional objects having an internal structure, wherein the structure is discontinuous and is composed from a plurality of patterns and bridging patterns formed on a plurality of levels, wherein a bridging level and pattern reside between previous and subsequent levels from which the bridging pattern obtains at least a portion of its pattern. A portion of the bridging pattern is obtained from the pattern on the previous level and a portion of the bridging pattern is obtained from the pattern on the subsequent level.

Abstract: Embodiments of the instant invention are directed to laser exposure systems that employ a pulsed solid state laser to provide a reactive response wavelength and a pulse repetition rate specifically optimized for application to solidification of a liquid photopolymer in a stereolithographic process. The solid state laser employs two second harmonic crystals for generating an emission wavelength at about 320-345 nm and a pulse repetition rate, wherein the pulse repetition rate is selected such that a resulting pulse separation at the target surface is less than a width of the beam when the beam is being scanned at a desired velocity and an average exposure deposited by the beam is equal to a desired amount.