Abstract: A method of operating a printer analyzes a printed test pattern in a low-contrast printing configuration. The method includes forming a printed test pattern having a plurality of rows of negative marks on an image receiving member, each negative mark in the plurality of rows of negative marks being surrounded by ink from at least a portion of the plurality of inkjets. The method further includes generating scanned image data of the test pattern and identifying a plurality of locations in the cross-process direction for the negative marks in at least one row of negative marks in the scanned image data of the test pattern.

Abstract: A three-dimensional object printing system improves the interlayer adhesion of an object. The printing system includes a platform on which a three-dimensional object is built. A material applicator in the printing system expels material to form layers of the object on the platform. The material applicator also includes a heater configured to heat the layer of the object ahead of the material applicator when the material applicator moves in a first direction and a second direction, both directions being parallel to the platform.

Abstract: A three-dimensionally printed object includes a plurality of different material regions that together define a surface region of the object. The plurality of different material regions includes a first material region and a second material region. The first material region has a first color, and the second material region has a second color that is different from the first color. The different material regions overlap from each other within the object by different amounts viewed from different directions so that different proportions of light from the plurality of different material regions are visible to an observer viewing the surface region of the three-dimensionally printed object from different view directions, different view angles, and with illumination lighting the surface region at different angles. A coloration of the surface region is altered based on the proportions of light from the plurality of different material regions visible to the observer.

Abstract: An extruder assembly for a three-dimensional object has an extrusion slot to enable faster three-dimensional object printing with greater precision. The extruder assembly includes an extruder body having an extrusion slot to enable a continuous filament of material to be extruded through the extrusion slot and at least one actuator operatively connected to the extruder body. The at least one actuator is configured to translate the extruder body in a horizontal plane and rotate the extruder body about a rotational axis.

Abstract: An additive manufacturing system operates at least one ejector and an extruder to form three-dimensional objects with photopolymer material and thermoplastic material. The system operates to deposit the two materials in a layer-by-layer manner. The photopolymer material provides high resolution finishes on the objects and the thermoplastic material enables strong and stable formation of internal portions of the objects.

Abstract: A three-dimensionally printed object includes a plurality of different material regions that together define a surface region of the object. The plurality of different material regions includes a first material region and a second material region. The first material region has a first color, and the second material region has a second color that is different from the first color. The different material regions overlap from each other within the object by different amounts viewed from different directions so that different proportions of light from the plurality of different material regions are visible to an observer viewing the surface region of the three-dimensionally printed object from different view directions, different view angles, and with illumination lighting the surface region at different angles. A coloration of the surface region is altered based on the proportions of light from the plurality of different material regions visible to the observer.

Abstract: A method of spatially and spectrally calibrating a spectrophotometer including: a) emitting a white light illumination output from a full width illumination source; b) illuminating a test patch with the white light illumination output; c) reflecting a portion of the white light illumination output from the test patch to form a white light reflected illumination output; d) receiving the white light reflected illumination output at first, second and third rows of photosensitive elements to form a first calibration data set; e) emitting a cyan light illumination output from the full width illumination source; f) illuminating the test patch with the cyan light illumination output; g) reflecting a portion of the cyan light illumination output from the test patch to form a cyan light reflected illumination output; and, h) receiving the cyan light reflected illumination output at the second and third rows of photosensitive elements to form a second calibration data set.

Abstract: A multi-nozzle extrusion printhead includes a chamber with an inlet to receive an extrusion material and a plurality of outlets fluidly coupled to the chamber. The printhead also includes a plurality of valves that control flow of extrusion material through the fluid outlets to nozzles in the printhead. Each valve includes a member and an electromechanical actuator configured to move the member to a first position to block a flow of the extrusion material through one of the fluid outlets and nozzles and to a second position to enable the flow of the extrusion material through the fluid outlet and nozzles.

Abstract: A method of operating a multi-nozzle extrusion printhead includes operating with a controller a first actuator to produce relative movement between the printhead and an image receiving surface along a predetermined path for one layer of a three-dimensional printed object. The method further includes first printing an outline of a given layer and then printing the interior of the given layer using a plurality of extrusion nozzles. The method further optionally includes extruding material through a portion of the plurality of nozzles and turning on or off individual nozzles to ensure the swaths printed in the interior conform to the profile of the outline.

Abstract: A 3D printer including a pin actuated printhead having an orifice through which a material is ejected, a material chamber to hold the material to be ejected, a channel connecting the material chamber to the orifice, a pin chamber, and an actuated pin within the pin chamber, wherein the actuated pin extends through the pin chamber to eject the material from the orifice. The printhead is configured to eject a material with a viscosity of 10,000 cP or more at an elevated temperature. The 3D printer further includes a material delivery system having a filament driver and a filament heater.

Abstract: A three-dimensional object printer includes a multi-nozzle extruder, at least one extrusion material supply, and a dispenser that provides extrusion material from the extrusion material supply to each of a plurality of channels, each channel supplying extrusion material to at least one nozzle in the multi nozzle extruder. The dispenser includes an inlet to receive extrusion material from at least one extrusion material supply, an outlet configured to direct the extrusion material to a channel in the plurality of channels, and an actuator configured to move the outlet into alignment with each channel in the plurality of channels.

Abstract: A three-dimensional object printer uses stereolithography to form a structure and then embed one or more objects in the structure. The printer includes a controller that operates a source of ultraviolet (UV) radiation to cure a portion of a liquid photopolymer at an interface between the liquid photopolymer and the external surface of an embedded object with reference to a meniscus formed between the liquid photopolymer and the external surface of an embedded object. The incorporation of the embedded object speeds formation of the final object and increases the durability of the final object.

Abstract: An inkjet printer implements a method for identifying values for parameters for pixels to be printed by the printer. The method uses thresholds in a stochastic screen with a set of functions for the parameter for each primary color supplied to the printheads in the printer to identify values for the parameters. The parameters can be, for example, a number of drops to print for a color, a size of the drops to eject to form a pixel, or the number of inkjets to operate to form the pixel.

Abstract: A three-dimensional object printer includes a controller that operates at least one ejector to place a layer of photopolymer material on a substrate. The controller is configured to cure the ejected photopolymer layer partially and position fiber on the cured layer before continuing to eject photopolymer material onto the fibers. The fibers can be loose or organized into a mesh. The pieces of mesh position on a cured layer can be pre-cut or a cutting device can be operated to cut pieces of mesh having a shape that corresponds to the shape of the layer of photopolymer material. The fibers reinforce the layers of photopolymer material and add strength and durability to the overall part being formed with the photopolymer material.

Abstract: A method of manufacturing a three-dimensional object is disclosed. The method includes operating a first ejector of a three-dimensional object printer to eject a first material towards a platen to form an object. The method further includes operating a second ejector of the three-dimensional object printer to eject a second material towards the platen to form support for portions of the object, the support being configured to provide support for portions of the object during the operation of the first ejector to form the object, at least one portion of the support having a body with at least one fluid path that connects at least one opening in the body to at least one other opening in the body. The method further includes connecting a fluid source to the at least one fluid path of the support to enable fluid to flow through the at least one fluid path to remove at least an inner portion the support from the object.

Abstract: According to exemplary methods, a print job including an electronic document having a color image is received into a computerized device having a marking device including a print engine. A sheet of the print job is analyzed by the computerized device. In the analysis, a contone of the color image is converted to multi-bit output using multi-level vector halftoning. Pairs of complementary colors are selected, and substitute color channels for drop sizes are determined for each pair of complementary colors. Binary vector halftoning is applied using the substitute color channels for each pair of complementary colors. It is determined if ink is to be printed for the complementary colors. Multi-level processing is applied to determine an amount of ink for one color of each of the pairs of complementary colors. Pixels of the color image are rendered using the ink amount for the color of the pair of complementary colors.

Abstract: A three-dimensional object printer generates image data of an object being formed in the printer with an optical sensor and identifies the heights of object features above a substrate on which the object is being formed. A controller operates one or more actuators to move the optical sensor at a plurality of distances above the object to generate image data of the object at a plurality of heights above the object. The controller identifies the distances of the features of the object with reference to the image data generated by the optical sensor and the focal length of the optical sensor.

Abstract: A print strategy periodically inserts sacrificial print media, such as a small number of sacrificial sheets of paper into a print job to exercise underused print head jets and prevent nozzle dry-up and/or degraded jetting integrity. This can be implemented with sacrificial sheets out of a tray used by a current print job or from another paper tray housing, for example, the widest stock currently installed in the image forming device. Jets that need to be exercised can be determined by using Feed-Forward image content from the Image Path, and those jets are exercised to print ink on the sacrificial sheet(s). The sacrificial sheet may be diverted to a bypass tray as scrap. Without the need for a purge cycle, or a cycle-down, the image forming device can continue seamlessly to the next print job without performance loss from using the previously under-used print head jets.

Abstract: A method of operating a three-dimensional object printer includes generation of a printed predetermined test pattern on a substrate in the printer with a plurality of ejectors in a printhead. An image sensor generates image data of the printed test pattern and a controller identifies a z-axis distance between the printhead and the substrate that receives the test pattern with reference to an identified dispersion between cross-process direction distances separating printed marks in the test pattern.

Abstract: A method for compensating for inoperative ejectors in a three-dimensional object printer has been developed. A printer detects an inoperative ejector in a printhead. The printer identifies functional ejectors that print at locations adjacent to locations where the inoperative ejector fails to print a drop. The printer modifies firing signals for the functional ejectors so those ejectors print drops having an increased drop volume at the locations adjacent to locations where the inoperative ejector fails to print a drop. The printer prints a first layer of material drops using the modified firing signals. The printer advances the printhead in the cross-process direction between layers so that locations where the inoperative ejector fails do print a drop do not coincide between layers.