Abstract: A method of three-dimensional fabrication of an object is disclosed. The method comprises: forming a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, at least one layer of the plurality of layers being formed at a predetermined and different thickness selected so as to compensate for post-formation shrinkage of the layer along a vertical direction. In various exemplary embodiments of the invention spread of building material of one or more layers is diluted at least locally such as to maintain a predetermined thickness and a predetermined planar resolution for the layer.

Abstract: A method of three-dimensional fabrication of an object is disclosed. The method comprises: forming a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, at least one layer of the plurality of layers being formed at a predetermined and different thickness selected so as to compensate for post-formation shrinkage of the layer along a vertical direction. In various exemplary embodiments of the invention spread of building material of one or more layers is diluted at least locally such as to maintain a predetermined thickness and a predetermined planar resolution for the layer.

Abstract: A method of producing an object by sequentially printing layers of construction material one on top of the other, the method comprising: providing the construction material at a first lower temperature; flowing the construction material through a heated flow path in a flow structure to heat the construction material and delivering the heated construction material to a heated reservoir in a printing head; and dispensing the heated construction material from the reservoir to build the object layer by layer.

Abstract: A three-dimensional printing system to print three-dimensional objects and a method of printed are disclosed. The system includes a printing apparatus to print three-dimensional objects and a controller to receive data from a material supply source and to control said printing apparatus.

Abstract: Methods of printing a three-dimensional object, layer by layer are provided. Layers are formed by a bulk inner region which may be formed by depositing a transparent material, a white material, a colored material or a combination thereof, and a color outline which includes voxels formed by depositing a colored building material.

Abstract: A printing head assembly with integrated purge mechanism is disclosed. The printing head assembly comprises: (a) a liquid dispensing head comprising one or more dispensing nozzles enclosed in a nozzle plate, driven by at least first and second pressures, and (b) a shielding mask including an opening in front of the one or more nozzles, wherein the opening being configured such that when printing liquid is dispensed from the head driven by the first pressure, the liquid being dispensed in pulses through the opening in the shielding mask, and (ii) when purge printing liquid is dispensed from the head driven by the second pressure, the liquid being drawn to a capillary gap formed between the shielding mask and the nozzle plate thereby removing the purge printing liquid from the nearby nozzles.

Abstract: Apparatus for producing a three-dimensional model by sequentially forming layers of photopolymer material one on top of the other responsive to data defining the three-dimensional model is disclosed. The apparatus includes at least one printing head configured to dispense the photopolymer material, an array of LEDs controllable to provide radiation to polymerize the photopolymer material and a controller. The controller is configured to control the at least one printing head to dispense the photopolymer material to sequentially form the layers of material. The controller is also configured to turn on the array of LEDs to provide the radiation to cure the photopolymer material when situated above the model and to turn off the array of LEDs when not situated above the model.

Abstract: A method for preventing detachment of a three-dimensional object from a printing tray of a printing apparatus is disclosed. The method includes printing a carpet of building material below and around the base of a three-dimensional object to be printed; and printing said three-dimensional object. The portions of the carpet that protrude out of the boundaries of the base of the three-dimensional object are coated with one or more layers of support material to help keep the carpet flexible and adhesive in texture.

Abstract: Apparatus for producing a three-dimensional model by sequentially forming layers of photopolymer material one on top of the other responsive to data defining the three-dimensional model is disclosed. The apparatus includes at least one printing head configured to dispense the photopolymer material, an array of LEDs controllable to provide radiation to polymerize the photopolymer material and a controller. The controller is configured to control the at least one printing head to dispense the photopolymer material to sequentially form the layers of material. The controller is also configured to turn on the array of LEDs to provide the radiation to cure the photopolymer material when situated above the model and to turn off the array of LEDs when not situated above the model.

Abstract: A scanning 3-D printing system comprises a printing platform movable in a printing direction and in an indexing direction, the printing platform comprising a printing head configured for dispensing building material while the printing platform is moving in a printing direction one pass at a time, and layer by layer, a roller configured for leveling the dispensed building material one pass at a time, wherein the roller is rotatably mounted on a roller axle, and wherein the roller axle extends over all passes of the printing system and is stationary in the indexing direction, a scraper configured for scraping excess building material off the roller, and a trough configured for collecting the building material scraped off the roller.

Abstract: A method of three-dimensional fabrication of an object is disclosed. The method comprises: forming a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, at least one layer of the plurality of layers being formed at a predetermined and different thickness selected so as to compensate for post-formation shrinkage of the layer along a vertical direction. In various exemplary embodiments of the invention spread of building material of one or more layers is diluted at least locally such as to maintain a predetermined thickness and a predetermined planar resolution for the layer.

Abstract: A three-dimensional printing system to print three-dimensional objects and a method of printed are disclosed. The system includes a printing apparatus to print three-dimensional objects and a controller to receive data from a material supply source and to control said printing apparatus.

Abstract: A method of producing an object by sequentially printing layers of construction material one on top of the other, the method comprising: providing the construction material at a first lower temperature; flowing the construction material through a heated flow path in a flow structure to heat the construction material and delivering the heated construction material to a heated reservoir in a printing head; and dispensing the heated construction material from the reservoir to build the object layer by layer.

Abstract: A printing device for dispending material on a heated substrate is provided. The device may include a printing head having one or more nozzles and a heat shield that partially masks a side of the printing head that faces the heated substrate when printing so as to reduce heat transfer from the substrate to the printing head. The shield includes a slot aligned with the one or more nozzles to enable passage of material from the one or more nozzles to the heated substrate.

Abstract: A method of three-dimensional fabrication of an object is disclosed. The method comprises: forming a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, at least one layer of the plurality of layers being formed at a predetermined and different thickness selected so as to compensate for post-formation shrinkage of the layer along a vertical direction. In various exemplary embodiments of the invention spread of building material of one or more layers is diluted at least locally such as to maintain a predetermined thickness and a predetermined planar resolution for the layer.

Abstract: A method of producing an object by sequentially printing layers of construction material one on top of the other, the method comprising: providing the construction material at a first lower temperature; flowing the construction material through a heated flow path in a flow structure to heat the construction material and delivering the heated construction material to a heated reservoir in a printing head; and dispensing the heated construction material from the reservoir to build the object layer by layer.

Abstract: A three-dimensional printing system to print three-dimensional objects and a method of printed are disclosed. The system includes a printing apparatus to print three-dimensional objects and a controller to receive data from a material supply source and to control said printing apparatus.

Abstract: A method for evaluating performance of a plurality of nozzles of a printing head includes repeatedly operating each of the nozzles to print test marks on a surface of a substrate, each of the test marks printed by that nozzle being printed at a different time. At least once during the repeated operation of each of the nozzles, at least some of the test marks are erased from the surface. The test marks that were printed by that nozzle are inspected for a feature that is indicative of the performance of that nozzle.

Abstract: A method for evaluating performance of a plurality of nozzles of a printing head includes repeatedly operating each of the nozzles to print test marks on a surface of a substrate, each of the test marks printed by that nozzle being printed at a different time. At least once during the repeated operation of each of the nozzles, at least some of the test marks are erased from the surface. The test marks that were printed by that nozzle are inspected for a feature that is indicative of the performance of that nozzle.

Abstract: Methods of printing a three-dimensional object, layer by layer are provided. Layers are formed by a bulk inner region which may be formed by depositing a transparent material, a white material, a colored material or a combination thereof, and a color outline which includes voxels formed by depositing a colored building material.