Abstract: A solid-state laser includes a high-absorption coefficient solid-state gain medium such as Nd:YVO.sub.4 that is side pumped with a semiconductor laser diode array. The resonant cavity of the solid-state laser is positioned so that the TEM.sub.00 mode is spaced from the face of the laser through which the laser is pumped by a distance sufficient to reduce diffraction losses but sufficiently near to allow coupling of pump light into the gain mode. The gain medium, the doping level of the gain medium, and the operating temperature of the pump laser are selected to efficiently couple pump light into the gain mode. The pump laser is positioned to side pump the gain medium without collimating or focusing optics between the pump laser and the face of the gain medium. A gap between the pump laser and the gain medium is empirically selected to match the angular extent of the pump laser output light to the height of the gain mode at the position of the gain mode fixed to optimize coupling and diffraction losses.

Abstract: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making three-dimensional objects with enhanced control of the temperature of the build environment. A modulated control signal is supplied to a heating element based on a difference between a desired build temperature and a detected temperature. The modulated signal result in the heater supplying, on average, more energy to the build chamber when the temperature difference is large and supplying, on average, less energy to the build chamber when the difference is small. The detection of the build chamber temperature may occur at one or more locations. If multiple locations are used, the detected temperatures may be averaged, or otherwise combined, to derive a single difference value that will be used to control the heater.

Abstract: A method is disclosed for making a molded refractory article comprising the steps of providing a mold including a molding pattern, the mold and molding pattern defining a mold cavity; filling the mold cavity around the molding pattern with a mixture comprising refractory particles and a heat fugitive binder; inserting a plurality of elements of relatively high melting point material into the mixture to displace a portion of the mixture; curing the mixture; separating the mold and molding pattern from the cured mixture; and sintering the combination of the cured mixture and mixture displacing elements to provide a reinforced molded refractory article. The mixture displacing elements preferably comprise a plurality of parallel tool steel rods. Also disclosed is an apparatus for molding the aforedescribed reinforced refractory article.

Abstract: Techniques for printing raster lines in a selective deposition modeling (SDM) system. Raster lines may be printed using different numbers of jets in each group in different passes. Moreover, full and partial head randomization is available. Selected raster lines are printed in one direction, although the print head prints in two directions. Furthermore, raster lines printing may be interlaced, and deposition order may be changed between layers.

Abstract: A solubilizing agent and a compound made by reacting selected nucleophiles, including fatty acid reactants and amines with an isocyanate are disclosed. The addition of the isocyanate and the different nucleophiles will create a di-urethane tetra-amide solubilizing agent product. The polyamide-solubilizing agent is useful as an ingredient in a phase change solid imaging material and as carrier compositions used to make phase change ink jet inks.

Abstract: Phase change compositions that are solid at ambient temperature and liquid at an elevated temperature above ambient temperature are disclosed for advantageous use in selective deposition modeling methods for building three-dimensional objects. A phase change composition according to the disclosed invention is a semi-crystalline component mixture having a freezing point of at least about 68.degree. C., a melting point of at least about 88.degree. C. and a viscosity of about 13 centipoise at 135.degree. C. The composition includes a plurality of waxes having a broad melting point range and molecular weight range. Three-dimensional objects having minimal curl, delamination and stress cracks can be produced at a faster rate than heretofore known by using selective deposition modeling techniques employing the disclosed compositions.

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: A novel thermopolymer material adapted for use in thermal stereolithography. More particularly, a thermopolymer material comprising a mixture of: a low shrinkage polymer resin; a low viscosity material such as paraffin wax; at least one microcrystalline wax; a toughening polymer; a plasticizer. Alternative embodiments further include components to improve the materials ability to transfer heat and to improve strength. The subject material, together with the described process greatly reduce part building distortions while retaining desirable toughness, strength and jetting properties.

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: 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: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making three-dimensional objects with enhanced control of coating parameters used when forming layers of liquid or other fluid-like material in preparation for forming laminae of the object. The each lamina of the object is treated as either a primary laminae or secondary laminae. Only minority portions of the secondary layers are solidified when their associated layers are formed. Primary laminae are solidified in majority portions, along with previously unsolidified portions of secondary lamina, when their associated layers are formed. Recoating parameters are supplied for groups of primary layers and secondary layers such that coating formation may be controlled differently for primary layers and for secondary layers. Coating control for secondary layers may be based on the position of individual secondary layers, or sets of secondary layers, relative to the primary layers.

Abstract: A rapid prototyping and manufacturing apparatus and method (e.g. stereolithographic apparatus and a method) for layer-by-layer formation of a three-dimensional object represented by cross-sectional data including a method and apparatus for deriving data for at least a portion of a region intermediate to two successive cross-sections of data for use in forming the three-dimensional object with improved surface resolution. Outward-facing regions on two or more successive cross-sectional layers of the object are compared to determine whether the outward-facing region(s) associated with one of the layers represents what was originally intended to be a smooth transitional region (i.e. a sloping region) between two cross-sections or a discontinuous region (i.e. vertical transitional region) between two cross-sections. The comparison may involve utilization of common boundaries between outward facing regions on the cross-sections.

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: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

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: This invention relates to the stepwise layer-by-layer formation of a three-dimensional object through application of the principles of stereolithography and to the automatic detection of surface features of each layer of a three-dimensional object to manufacture parts more reliably, more accurately and more quickly. Automatic detection of trapped volume regions and size of solidified cross-sectional regions are disclosed. Automatic selection of recoating styles is made based on(1) the detected regions, (2) empirically or otherwise determined optimum recoating styles for different types of regions, and (3) a look-up table, other correlation system, or processor for associating recoating style information with laminae containing particular identified regions.

Abstract: The invention involves an improved system for producing a three-dimensional object by forming successive cross-sections of the object from a material which is normally solid but which may be made flowable, including using data manipulation for converting a three-dimensional object representation into cross-sectional representations.

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.