Model generation system having closed-loop extrusion nozzle positioning

A method for fabricating a three-dimensional object in accordance with a computer-generated specification of the object in three dimensions, comprising the steps of:

• controllably positioning an extruding means for extruding a self-supporting material in accordance with the specification of the object in three dimensions;
• generating a feedback signal that is indicative of at least a location of a previously extruded portion of the material;
• and
• responsive to the feedback signal, modifying, if required, further positioning of the extruding means to compensate for a deviation of the location from a location specified by the specification of the object in three dimensions.

Apparatus for fabricating a three-dimensional object in accordance with a computer generated specification of the object in three dimensions, comprising:

• means for slicing the computer generated specification of the object in three dimensions into a plurality of horizontal layers;
• means for extruding a self-supporting material;
• means or controllably positioning the extruding means, in accordance with the sliced specification of the object in three dimensions, to sequentially fabricate the object layer by layer;
• and
• means for generating a feedback signal that is indicative of at least a location of a previously extruded portion of the self-supporting material, the feedback signal being coupled to the positioning means;
• wherein
• the positioning means is responsive to the feedback signal for modifying, if required, further positioning of the extruding means to compensate of a deviation of the location from a location specified by the specification of the object in three dimensions.

Apparatus for fabricating a three-dimensional object in accordance with a computer generated specification of the object, comprising:

• means for slicing the computer generated specification into a plurality of horizontal layers;
• means for extruding a self-supporting material;
• means or controllably positioning the extruding means to sequentially fabricate the object layer by layer;
• and
• means for generating a feedback signal that is indicative of at least a location of a previously extruded portion of the self-supporting material, the feedback signal being coupled to the positioning means;
• wherein
• the positioning means is responsive to the feedback signal for modifying, if required, further positioning of the extruding means to compensate for a deviation of the location from a location specified by the specification, and
• wherein the positioning means is operable for positioning the extruding means at a previously extruded layer for extruding additional material at the previously extruded layer.

A system for fabricating a three-dimensional object in accordance with a specification of the object, comprising:

• means for extruding a material;
• means for controllably positioning the extruding means in accordance with the specification of the object;
• and
• means, having an output coupled to the positioning means, for generating a feedback signal that is indicative of at least one characteristic of a most recently extruded portion of the material, wherein the generating means comprises imaging means, wherein the feedback signal is indicative of at least a location of the most recently extruded portion of the material, and wherein the imaging means is comprised of a Cassegrain optical system disposed for relaying an image of at least the most recently extruded portion of the material.

A system for fabricating a three-dimensional object in accordance with a specification of the object, comprising:

• means for extruding a material;
• means for controllably positioning the extruding means in accordance with the specification of the object;
• and
• means, having an output coupled to the positioning means, for generating a feedback signal that is indicative of at least one characteristic of a most recently extruded portion of the material, wherein the generating means comprises imaging means, wherein the feedback signal is indicative of at least a location of the most recently extruded portion of the material, and wherein the imaging means is comprises of a confocal line camera system disposed for imaging at least the most recently extruded portion of the material.

A system for fabricating a three-dimensional object in accordance with a specification of the object, comprising:

• means for extruding a material;
• means for controllably positioning the extruding means in accordance with the specification of he object;
• and
• means, having an output coupled to the positioning means, for generating a feedback signal that is indicative of at least one characteristic of a most recently extruded portion of the material, wherein the generating means comprises infrared emission imaging means, and wherein the feedback signal is indicative of a location of the most recently extruded portion of the material and also a temperature of the most recently extruded portion of the material.

A system for fabricating a three-dimensional object in accordance with a specification of the object in three dimensions, comprising:

• means having at least one orifice for extruding a self-supporting material;
• means for controllably positioning the extruding means in accordance with the specification of the object in three dimensions;
• and
• means, having an output coupled to the positioning means, for generating a feedback signal that is indicative of at least one characteristic of a previously extruded portion of the material, wherein the generating means comprises at least one source of electromagnetic radiation for illuminating a region in the vicinity of the at least one orifice, means for detecting a potion of the electromagnetic radiation that results from an illumination of a surface of the self-supporting material that has been extruded from the at least one orifice, and means, responsive to a signal output by said detecting means, for providing to said positioning means information that indicates a location of the self-supporting material that has been extruded rom the at least one orifice;
• and wherein
• said positioning means is responsive to the information for modifying, if required, further positioning of the extruding means to compensate for a deviation of the location of the self-supporting material from an expected location that is specified by the specification of the object in three dimensions.