Abstract: Apparatus and method for stereolithographically forming a three-dimensional object includes a vessel for holding a building material and a smoothing member for forming a uniform coating over a previously formed layer of the object. The smoothing member has a plurality of blades. The smoothing member is swept over a previously formed layer of the object, in at least two directions. Different clearances between the lower surface of the smoothing member and the upper surface of the previously formed layer are used to provide a uniform coating for a subsequent layer over the previously formed layer. The sweeping velocity of the smoothing member can be varied. Retractable needles are attached to the smoothing member for adjusting a blade gap between a lower surface of the smoothing member and the surface of the building material.

Abstract: The instant invention is directed to related methods of producing a three-dimensional object by dispensing sheets of a material, capable of physical transformation upon exposure to synergistic stimulation, onto a substantially flat working surface of a previous cross-section. In one preferred embodiment, sheets of a photoresist are employed which change solubility upon exposure to electromagnetic radiation. In other preferred embodiments, non-photoreactive sheets are employed, which ablate upon exposure to infrared radiation.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: An improved method for stereolithographically making an object by alternating the order in which similar sets of vectors are exposed over two or more layers. In another method, a pattern of tightly packed hexagonal tiles are drawn. Each tile is isolated from its neighboring tiles by specifying breaks of unexposed material between the tiles. Using an interrupted scan method, vectors are drawn with periodic breaks along their lengths. In another method, modulator and scanning techniques are used to reduce exposure problems associated with the acceleration and deceleration of the scanning system when jumping between vectors or changing scanning directions.

Abstract: An improved method for stereolithographically making an object by alternating the order in which similar sets of vectors are exposed over two or more layers. In another method, a pattern of tightly packed hexagonal tiles are drawn. Each tile is isolated from its neighboring tiles by specifying breaks of unexposed material between the tiles. Using an interrupted scan method, vectors are drawn with periodic breaks along their lengths. In another method, modulator and scanning techniques are used to reduce exposure problems associated with the acceleration and deceleration of the scanning system when jumping between vectors or changing scanning directions.

Abstract: A method and apparatus for making high resolution objects by stereolithography utilizing low resolution materials which are limited by their inability to form unsupported structures of desired thinness and/or their inability to form coatings of desired thinness. Data manipulation techniques, based on layer comparisons, are used to control exposure in order to delay solidification of the material on at least portions of at least some cross-sections until higher layers of material are deposited so as to allow down-facing features of the object to be located at a depth in the building material which is equal to or exceeds a minimum cure depth that can effectively be used for solidifying these features. Similar data manipulations are used to ensure minimum reliable coating thicknesses exist, above previously solidified material, before attempting solidification of a next layer. In addition, horizontal comparison techniques are used to provide enhanced cross-sectional data for use in forming the object.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminas, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: An apparatus and related method for providing a substantially flat working surface of photocurable resin for the formation of a next layer of a stereolithographic part. A substantially flat surface of a rigid member is substantially covered by and spaced from the resin by a substance or film, which is placed in contact with the photocurable resin to form the working surface. Various embodiments are described including where the rigid member is a quartz including a fused silica plate, a bar, a vat wall, the face of a CRT, a fiber-optic bundle, or the bottom of a piston, and also including embodiments where the substance or film is a thin teflon or mylar film, an inert liquid, wax, a thin coating of trichlorosilane or ethoxysilane, or oxygen-saturated resin. Embodiments are also described whereby the next layer is exposed by transmitting solidifying radiation through the member and substance or film.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being specially processed to reduce curl and distortion, and increase resolution, strength, accuracy, speed and economy of reproduction even for rather difficult object shapes, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: An improved method for stereolithographically forming a three-dimensional object wherein ordinarily solidified internal walls of the object remain at least partially unsolidified. Any unsolidified medium within the object can be drained from the internal walls of the object prior to post-curing so that a hollow three-dimensional object is formed. The object is formed on a layer by layer basis with the internal portion of each layer of the object formed as a grid of solidified portions and unsolidified portions wherein the solidified and unsolidified portions are different on each layer. Objects formed in this manner can be used as patterns in investment casting.

Abstract: An improved stereolithographic apparatus and method is described. In one embodiment, the improvement includes immersing at least a portion of a part in a volume of a liquid solvent in a vapor degreaser while subjecting the portion to ultrasonic agitation to substantially remove excess resin. Several examples of solvents are provided, including ethanol, and Freon TMS. In a second embodiment, the improvement includes building the part on a layer of liquid resin supported by a volume of a dense, immiscible, and UV transparent intermediate liquid, and integratably immersing at least a portion of the built part in the intermediate liquid, and then either subjecting the immersed portion to ultrasonic agitation to substantially remove excess resin, or subjecting the immersed portion to UV light. Several examples of intermediate liquids are provided, including perfluorinated fluids, such as Fluorinert FC-40, and water-based salt solutions, such as solutions of magnesium sulfate or sodium chloride in water.

Abstract: A stereolithographic system for automatically generating three-dimensional objects on a layer by layer basis by alternately forming layers of medium over previously formed layers of the object and selectively solidifying successive layers of medium at a surface of a body of the medium whereby the object is formed from a plurality of solidified and adhered layers. The surface of the body of medium is maintained at a desired working surface, for example by detecting its level and relatively adjusting it and the working surface so that they coincide.

Abstract: Methods of coating stereolithographic parts and smoothing over characteristic surface discontinuities having alternating recesses and peaks. A stereolithographic part is first substantially covered with a substance capable of becoming less viscous when heated at a temperature which does not substantially thermally degrade the part, wherein the heated substance has an appropriate surface tension. Then, the substance is heated to that temperature until the substance flows preferentially into the recesses of the surface discontinuities and away from the peaked surface discontinuities. The substance will thereafter form a short surface connection over the recesses of the discontinuities through the surface tension of the heated substance. The substance is then polymerized or hardened either by cooling, thermally setting or by UV curing.

Abstract: Systems for and methods of generating three-dimensional objects from a medium capable of selective physical transformation upon exposure to synergistic stimulation, whereby sheets of medium corresponding to cross-sectional layers of the three-dimensional object are dispensed from a source, the dispensed sheets then being selectively exposed to synergistic stimulation thereby forming a layer of the three-dimensional object, the areas not exposed to synergistic stimulation being removed, and whereby successive sheets corresponding to successive cross-sectional layers are dispensed and selectively exposed to synergistic stimulation and integrated together with preceding layers to provide substantially a layer by layer buildup of the three-dimensional object, thereby forming the three-dimensional object.