Abstract: A solid imaging apparatus and method employing sub-pixel shifting in multiple exposures of the digitally light projected image of a cross-section of a three-dimensional object on a solidifiable liquid medium. The multiple exposures provide increased resolution, preserving image features in a three-dimensional object and smoothing out rough or uneven edges that would otherwise be occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Algorithms are used to select pixels to be illuminated within the boundary of each image projected in the cross-section being exposed.

Abstract: A solid imaging apparatus and method employing sub-pixel shifting in multiple exposures of the digitally light projected image of a cross-section of a three-dimensional object on a solidifiable liquid medium. The multiple exposures provide increased resolution, preserving image features in a three-dimensional object and smoothing out rough or uneven edges that would otherwise be occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Algorithms are used to select pixels to be illuminated within the boundary of each image projected in the cross-section being exposed.

Abstract: A solid imaging apparatus and method employing sub-pixel shifting in multiple exposures of the digitally light projected image of a cross-section of a three-dimensional object on a solidifiable liquid medium. The multiple exposures provide increased resolution, preserving image features in a three-dimensional object and smoothing out rough or uneven edges that would otherwise be occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Algorithms are used to select pixels to be illuminated within the boundary of each image projected in the cross-section being exposed.

Abstract: A solid freeform fabrication method and apparatus for making objects in a layer by layer manner in which the objects have special geometrical features requiring specialized control parameters. The method and apparatus automatically determines and selects the build parameters for the build process based on automatic part feature recognition. A general build style is first determined having a plurality of default parameters for building the object. Data representing the object is imported and oriented with a Z-axis. The data is then processed by slicing software that automatically identifies special build types for specific ranges of Z-values and selects the alternative parameters needed to successfully build these features. Preferably a look-up table contains special sets of values for the parameters for each special build type possible in which the slicing algorithm can select from. During slicing, operator intervention is not needed to prepare all the parameters necessary for a successful build.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure and the improved support structure is described. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.

Abstract: A method of forming a three-dimensional object in layerwise fashion by selectively solidifying a build material. The method solidifies the main part area, delays or pauses for a desired period of time to permit shrinkage to occur, and then, in multiple drawings of the main part borders, solidifies the borders from the portion closest to the main part outwardly to the portion farthest from the main part.

Abstract: An improved slicing technique is disclosed that employs micro-slicing or intermediate slices by identifying intermediate triangle vertices in the STL data and passing slice layers through each intermediate vertex to create a final build object or part that has smoother contouring, greater accuracy and an improved surface appearance than parts obtained using prior slicing methods.

Abstract: A method of forming a three-dimensional object in layerwise fashion by selectively solidifying a build material in a reinforced cyclical fashion. The method solidifies a first fully cured layer of build material and then partially solidifies at least one partially cured intermediate layer of build material having areas of liquid build material and areas of solidifying build material. The method repeats the cycle by solidifying a next overlying fully cured layer of build material and also the underlying liquid areas of build material in the at least one partially cured intermediate layer of build material.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure is disclosed. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.

Abstract: Rapid prototyping and manufacturing (e.g. stereolithography) methods and apparatus are disclosed that form objects with enhanced accuracy and small feature retention. Techniques for offsetting cross-sectional boundary data to at least partially accommodate for solidification width induced in a medium by a beam of radiation are provided. One technique uses repeated small offsets to yield an effective offset of a desired amount. A second technique uses displacement vectors to determine where and to what extent to offset the boundary segments. The offset amount for each vertex is determined based on a combination of the (1) the vertex angle, and (2) a predefined variable offset criteria which is different for at least two predefined ranges of angles. A third technique converts a single boundary segments into a plurality of offset boundary segments when the single boundary segment can not undergo the full desired offset without violating another offsetting rule.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.

Abstract: A method of manipulating data in a method for forming a three-dimensional object layer by layer from an ink jettable, solidifiable material by providing data corresponding to a plurality of polygons defining the outer surfaces of a plurality of three-demiensional objects and providing sets of x, y, and z coordinates corresponding to each layer and identifying x and y coordinates with each z coordinate such that directional values and counter values are determined for each y coordinate in a first set of coordinates generated. A second set of y coordinates are generated according to a formula that permits the determined layers to be processed to form a three-dimensional object.

Abstract: A method of forming a three-dimensional object in layerwise fashion by selectively solidifying a build material is disclosed. The method solidifies the main part area, delays or pauses for a desired period of time to permit shrinkage to occur, and then, in multiple drawings of the main part borders, solidifies the borders from the portion closest to the main part outwardly to the portion farthest from the main part.

Abstract: A solid freeform fabrication method and apparatus for making objects in a layer by layer manner in which the objects have special geometrical features requiring specialized control parameters. The method and apparatus automatically determines and selects the build parameters for the build process based on automatic part feature recognition. A general build style is first determined having a plurality of default parameters for building the object. Data representing the object is imported and oriented with a Z-axis. The data is then processed by slicing software that automatically identifies special build types for specific ranges of Z-values and selects the alternative parameters needed to successfully build these features. Preferably a look-up table contains special sets of values for the parameters for each special build type possible in which the slicing algorithm can select from. During slicing, operator intervention is not needed to prepare all the parameters necessary for a successful build.

Abstract: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making three-dimensional objects on a layer by layer basis by selectively exposing layers of material to prescribed stimulation, using a beam having a first smaller diameter and a beam having a second larger diameter, to form laminae of the object. The power of the smaller beam is typically lower than the power of the larger beam. Object formation is controlled by data representing portions of the layers to be exposed with the larger beam (large spot portions) and those portions to be exposed with the smaller beam (small spot portions). In a preferred embodiment, portions exposed with the larger beam are formed first, for a given layer. Portions are exposed with the small beam next. Thereafter the entire perimeter of the laminae is traced using the small beam.

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: 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. In another method, a capability for automatically inserting vents an drains into a three-dimensional object representation is provided.

Abstract: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making high resolution objects utilizing low resolution materials which are limited by their inability to reliably form coatings of a desired thickness. The formation of coatings of such materials is limited to a Minimum Recoating Depth (MRD), when formed over entirely solidified laminae, which is thicker than the desired layer thickness or object resolution. Data manipulation techniques result in layers of material (and laminae) of the object being categorized as non-consecutive primary layers (laminae) and secondary layers (laminae) positioned intermediate to the primary layers (laminae).

Abstract: A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making three-dimensional objects with simplified correlation of building parameters with object data. Object data is preferably correlated to (1) object build parameters that are used in solidifying object portions of layers of the material, (2) recoating parameters that are used in forming layers of material that include object data, (3) support build parameters that are used in solidifying support portions of layers of the material, (4) recoating parameters that are used in forming layers of material that include support data but no object data, and (5) parameters for use in generating a support structure that will be used to support the object during its formation. A style file is identified with each set of parameters. An algorithm (i.e. style wizard) is used to select among a plurality of styles of each type.

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.