Abstract: An apparatus and a method for calibrating and normalizing a stereolithographic apparatus so that a reaction means directed by a positioning means supplied with positioning means information may be positioned accurately on a designated surface of a working medium. One or more sensors fixed in location with respect to the designated surface of the working medium are utilized to correlate positioning means information with specific locations on the designated surface of the working medium. Other locations intermediate the specific locations may then be determined by the technique of linear interpolation.

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 apparatus and a method for profiling the intensity of a beam and thus measuring the overall intensity and power of a beam are disclosed that have particular use in stereolithography. A beam sensor comprising a pinhole in a plate and a photodetector behind the pinhole measures the intensity of portions of a beam as the beam is moved over the beam sensor. Software associated with the sensors in a computer controls the scanning mechanism for the beam so that the beam is shifted to find the pinhole and move across it in order to develop the intensity profile. The invention can be used to detect drift in the scanning mechanism, determine the focus of the beam, and predict the depth and width of photopolymer cured by the beam.

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 stereolithographic apparatus (SLA) and an improved method for generating a part from curable material. The invention utilizes control and/or knowledge of depths of penetration of actinic radiation into a vat of photopolymer to determine and/or control and/or produce desirable characteristics associated with the creation of parts. From a predictive point of view, these desirable characteristics may include determination of cure depth from a given exposure, determination cure width, determination of required minimum surface angle (MSA), determination of optimum skin fill spacing, the strength of cross sections of partially polymerized material, amount of curl type distortion, and necessary overcure to attain adhesion between layers, etc. These determinations can lead to the use of particular building techniques to insure adequate part formation.

Abstract: An improved stereolithography system and method for curing a stereolithography-produced part, including at least some material that is no more than partially transformed, by exposing the part to off-peak absorptive wavelengths of synergistic stimulation to achieve a more uniform cure.

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: A stereolithographic device and method including a process module, a control module and a service module. A laser is employed through a dynamic mirror system controlled by the control module to generate solidified cross sections of a selected part design on the surface of a photocurable polymer liquid. By lowering cured cross sections into the vat, additional cross sections can be perpared and joined therewith to define a prototype product. A stationary mirror in the beam path between the dynamic mirror system and the photocurable polymer is employed to make the system more compact and practical. A calibration and normalization process provides correction to distortions and misalignment of the stationary mirror.

Abstract: An apparatus and a method for calibrating and normalizing a stereolithographic apparatus so that a reaction means directed by a positioning means supplied with positioning means information may be positioned accurately on a designated surface of a working medium. One or more sensors fixed in location with respect to the designated surface of the working medium are utilized to correlate positioning means information with specific locations on the designated surface of the working medium. Other locations intermediate the specific locations may then be determined by the technique of linear interpolation.

Abstract: An improved sterolithography system for generating a three-dimensional object from object defining information, the information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object is described. A stereolithographic distortion known as curl is reduced by the system, and several techniques to eliminate or reduce curl are utilized by the system, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques.

Abstract: An improved stereolithography system and method for curing a stereolithographically-produced part, including at least some material that is no more than partially transformed, by exposing the part to off-peak-absorptive wavelengths of synergistic stimulation to achieve a more uniform cure.

Abstract: An apparatus and a method for profiling the intensity of a beam and thus measuring the overall intensity and power of a beam are disclosed that have particular use in stereolithography. A beam sensor comprising a pinhole in a plate and a photodetector behind the pinhole measures the intensity of portions of a beam as the beam is moved over the beam sensor. Software associated with the sensors in a computer controls the scanning mechanism for the beam so that the beam is shifted to find the pinhole and move across it in order to develope the intensity profile. The invention can be used to detect drift in the scanning mechanism, determine the focus of the beam, and predict the depth and width of photopolymer cured by the beam.

Abstract: An improved sterolithography 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, and 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 a method for correcting for drift in production of objects by stereolithography is disclosed. A beam sensor comprising a pinhole in a plate and a photodector behind the pinhole is used to obtain the apparent position of the beam at calibration time and subsequently. A comparison between the prior and present apparent position of the sensor is made in order to determine a drift error correction term to be used to compensate for drift and thereby improve the accuracy and pointing repeatability of the scanning mechanism.