초록 ▼

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, parti

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. A stereolithographic distortion known as curl is defined, and several techniques to eliminate or reduce curl are described, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques. In addition, a quantitative measurement of curl known as the curl factor, and a test part known as a quarter cylinder are described, which together can be used to measure the effectiveness of the above techniques in reducing curl.

대표청구항 ▼

An improved method for forming at least a portion of a three-dimensional object from a material capable of solidification upon exposure to synergistic stimulation with reduced distortion, the method comprising the steps of forming layers of said material and selectively exposing said layers to said

An improved method for forming at least a portion of a three-dimensional object from a material capable of solidification upon exposure to synergistic stimulation with reduced distortion, the method comprising the steps of forming layers of said material and selectively exposing said layers to said synergistic stimulation to form successive cross-sections of the three-dimensional object and build up the object cross-section by cross-section, wherein the improvement comprises the steps of: exposing a first portion of a first layer to synergistic stimulation to cause solidification of said first portion; exposing a second portion of a second layer, which is different from said first layer, with a first exposure of synergistic stimulation, the second portion at least partially overlaying said first portion of said first layer, characterized in that the first exposure causes at least partial solidification of said second portion but does not cause adhesion between said second portion and said first portion; and exposing at least part of said second portion to at least a second exposure of synergistic stimulation which occurs after said first exposure, characterized in that said at least second exposure results in adhesion between said first and second layers.