SYSTEMS AND METHODS FOR ADDITIVE MANUFACTURING USING PIXEL SHIFTING

An additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted to efficiently print one or more layers of a component.

FIELD

The present subject matter relates generally to an additive manufacturing apparatus and methods of operating the same.

BACKGROUND

Additive manufacturing is a process in which material is built up layer-by-layer to form a component. Stereolithography (SLA) is a type of additive manufacturing process that employs a tank of radiant-energy curable photopolymer “resin” and a curing energy source such as a laser. Similarly, Digital Light Processing (DLP) three-dimensional (3D) printing employs a two-dimensional image projector to build components one layer at a time. For each layer, the energy source draws or flashes a radiation image of the cross section of the component onto the surface of the resin. Exposure to the radiation cures and solidifies the pattern in the resin and joins it to a previously-cured layer.

Additive manufacturing processes may be used to form various components. There has been some challenges efficiently printing components, printing large components, and printing components with fidelity-critical features. Accordingly, additive manufacturing processes and systems that address such challenges would be a welcome addition to the art.

DETAILED DESCRIPTION

As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify a location or importance of the individual components. The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. The terms “upstream” and “downstream” refer to the relative direction with respect to a resin support movement along the manufacturing apparatus. For example, “upstream” refers to the direction from which the resin support moves, and “downstream” refers to the direction to which the resin support moves. The term “selectively” refers to a component's ability to operate in various states (e.g., an ON state and an OFF state) based on manual and/or automatic control of the component.

Moreover, the technology of the present application will be described in relation to exemplary embodiments. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary.

The present disclosure is generally directed to an additive manufacturing apparatus that implements various manufacturing processes such that successive layers of material(s) are provided on each other to “build-up,” layer-by-layer, a three-dimensional component. The successive layers generally cure together to form a monolithic component which may have a variety of integral sub-components.

In one example aspect, an additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted and flashed to efficiently print one or more layers of a component. By moving the grid and/or pixels and flashing them intelligently as disclosed herein, pixelization can be minimized. For instance, round features of a component can be made rounder and sharp edges can be made sharper. Moreover, by intelligently shifting and flashing the grid and/or pixels, larger components may be produced without loss of resolution. This allows for more diverse part creation and/or reduces the overall packaging of the apparatus.

Referring to the drawings wherein identical reference numerals denote the similar elements throughout,FIGS.1A and1Bschematically illustrate an example apparatus10for forming a component12. The apparatus10can include one or more of a support plate14, a window16, a stage18that is movable relative to the window16, and a radiant energy device20, which, in combination, may be used to form any number (e.g., one or more) of additively manufactured components12. For reference, the apparatus10defines a Z-axis direction (labeled as Z inFIGS.1A and1B), an X-axis direction (labeled as X inFIGS.1A and1B), and a Y-axis direction (labeled as Y inFIGS.1A and1B), each of which is mutually perpendicular such that an orthogonal coordinate system is defined. The Z-axis direction can be a vertical direction, for example.

As depicted inFIG.1A, the apparatus10includes a feed module22, which may include a first mandrel22A, and a take-up module24, which may include a take-up mandrel24A, that are spaced-apart with a resin support26extending therebetween. A portion of the resin support26can be supported from underneath by the support plate14. Suitable mechanical supports (frames, brackets, etc.) and/or alignment devices may be provided for the mandrels22A,24A and the support plate14. The first mandrel22A and/or the take-up mandrel24A can be configured to control the speed and direction of the resin support26such that the desired tension and speed is maintained in the resin support26through a drive system28. By way of example and not limitation, the drive system28can be configured as individual motors associated with the first mandrel22A and/or the take-up mandrel24A. Moreover, various components, such as motors, actuators, feedback sensors, and/or controls can be provided for driving the mandrels22A,24A in such a manner to maintain the resin support26tensioned between the aligned mandrels22A,24A and to wind the resin support26from the first mandrel22A to the take-up mandrel24A.

In various embodiments, the window16is transparent and can be operably supported by the support plate14. Further, the window16and the support plate14can be integrally formed such that one or more windows16are integrated within the support plate14. Likewise, the resin support26is also transparent or includes transparent portions. As used herein, the terms “transparent” and “radiotransparent” refer to a material that allows at least a portion of radiant energy of a selected wavelength to pass through. For example, the radiant energy that passes through the window16and the resin support26can be in the ultraviolet spectrum, the infrared spectrum, the visible spectrum, or any other practicable radiant energy. Non-limiting examples of transparent materials include polymers, glass, and crystalline minerals, such as sapphire or quartz.

The resin support26extends between the feed module22and the take-up module24and defines a resin surface30, which is shown as being planar, but could alternatively be arcuate (depending on the shape of the support plate14). In some instances, the resin surface30may be defined by the resin support26and may be positioned to face the stage18with the window16on an opposing side of the resin support26from the stage18. For purposes of convenient description, the resin surface30may be considered to be oriented parallel to an X-Y plane of the apparatus10. As used herein, the X-axis refers to the machine direction along the length of the resin support26. As used herein, the Y-axis refers to the transverse direction across the width of the resin support26and generally perpendicular to the machine direction. As used herein, the Z-axis refers to the stage direction that can be defined as the direction of movement of the stage18relative to the window16.

The resin surface30may be configured to be “non-stick”, that is, resistant to adhesion of a cured resin R. The non-stick properties may be embodied by a combination of variables such as the chemistry of the resin support26, its surface finish, and/or applied coatings. For instance, a permanent or semi-permanent non-stick coating may be applied. One non-limiting example of a suitable coating is polytetrafluoroethylene (“PTFE”). In some examples, all or a portion of the resin surface30may incorporate a controlled roughness or surface texture (e.g. protrusions, dimples, grooves, ridges, etc.) with nonstick properties. Additionally or alternatively, the resin support26may be made in whole or in part from an oxygen-permeable material.

For reference purposes, an area or volume immediately surrounding the location of the resin support26and the window16or transparent portion defined by the support plate14may be defined as a build zone32.

A deposition assembly34may be positioned along the resin support26. In the illustrated embodiment, the material deposition assembly34includes a vessel36and a reservoir40. A conduit38extends from the vessel36to direct resin from the vessel36to the reservoir40. The conduit38may be positioned along a bottom portion of the vessel36such that the resin R may be gravity fed from the vessel36to the conduit38, which may generally prevent the introduction of air to the resin R as the resin R is transferred into and/or through the conduit38. In some instances, a filter may be positioned upstream, downstream, and/or within the conduit38with respect to the flow of resin from the vessel36to the reservoir40. In such instances, the resin may be gravity fed through the filter prior to entering the reservoir40to catch various agglomerates, partially cured resin pieces, and/or other foreign objects that may affect the resin once it is thinned out on the resin support26or may affect the quality of the component12.

The reservoir40may include any assembly to control the thickness of the resin R applied to the resin support26, as the resin support26passes under and/or through the reservoir40. The reservoir40may be configured to maintain a first amount volume of the resin R and define a thickness of the resin R on the resin support26as the resin support26is translated in the X-axis direction. The vessel36may be positioned above the reservoir40in the Z-axis direction, or in any other position, and configured to maintain a second amount volume of the resin R. In various embodiments, when the first amount volume of the resin R deviates from a predefined range, additional resin R is supplied from the vessel36to the reservoir40.

In the illustrated example ofFIG.1B, the resin support26may be in the form of a vat42that is configured to isolate debris that could contaminate the build from usable resin R. The vat42may include a floor44and a perimeter wall46. The perimeter wall46extends from the floor44. Inner surfaces of the floor44and the perimeter wall46define a receptacle48for receiving the resin R. A drive system may be provided for moving the vat42relative to the stage18parallel to the X-direction between the build zone32and a position at least partially external to the build zone32. However, it will be appreciated that, in other embodiments, the resin support26may be stationary.

Referring still toFIGS.1A and1B, the resin R includes any radiant-energy curable material, which is capable of adhering or binding together the filler (if used) in the cured state. As used herein, the term “radiant-energy curable” refers to any material which solidifies or partially solidifies in response to the application of radiant energy of a particular frequency and energy level. For example, the resin R may include a photopolymer resin containing photo-initiator compounds functioning to trigger a polymerization reaction, causing the resin R to change from a liquid (or powdered) state to a solid state. Alternatively, the resin R may include a material that contains a solvent that may be evaporated out by the application of radiant energy. The uncured resin R may be provided in solid (e.g. granular) or liquid form, including a paste or slurry. Furthermore, the resin R can have a relatively high viscosity resin that will not “slump” or run off during the build process. The composition of the resin R may be selected as desired to suit a particular application. Mixtures of different compositions may be used. The resin R may be selected to have the ability to out-gas or burn off during further processing, such as a sintering process.

Additionally or alternatively, the resin R may be selected to be a viscosity reducible composition. These compositions reduce in viscosity when a shear stress is applied or when they are heated. For example, the resin R may be selected to be shear-thinning such that the resin R exhibits reduced viscosity as an amount of stress applied to the resin R increases. Additionally or alternatively, the resin R may be selected to reduce in viscosity as the resin R is heated.

The resin R may incorporate a filler. The filler may be pre-mixed with resin R, then loaded into the deposition assembly34. Alternatively, the filler may be mixed with the resin R on the apparatus10. The filler includes particles, which are conventionally defined as “a very small bit of matter.” The filler may include any material that is chemically and physically compatible with the selected resin R. The particles may be regular or irregular in shape, may be uniform or non-uniform in size, and may have variable aspect ratios. For example, the particles may take the form of powder, of small spheres or granules, or may be shaped like small rods or fibers.

The composition of the filler, including its chemistry and microstructure, may be selected as desired to suit a particular application. For example, the filler may be metallic, ceramic, polymeric, and/or organic. Other examples of potential fillers include diamond, silicon, and graphite. Mixtures of different compositions may be used. In some examples, the filler composition may be selected for its electrical or electromagnetic properties, e.g. it may specifically be an electrical insulator, a dielectric material, an electrical conductor, and/or magnetic.

The filler may be “fusible,” meaning it is capable of consolidation into a mass upon application of sufficient energy. For example, fusibility is a characteristic of many available powders including but not limited to polymeric, ceramic, glass, and metallic. The proportion of filler to resin R may be selected to suit a particular application. Generally, any amount of filler may be used so long as the combined material is capable of flowing and being leveled, and there is sufficient resin R to hold together the particles of the filler in the cured state.

In some embodiments, a reclamation system50may be configured to remove at least a portion of the resin R that remains on the resin support26after the resin support26is removed from a build zone32. For example, the reclamation system50may include a collection structure, such as a wiper assembly, a blade assembly, and/or any other removal assembly.

With further reference toFIGS.1A and1B, the stage18is capable of being oriented parallel to the resin surface30. Various devices may be provided for moving the stage18relative to the window16parallel to the Z-axis direction. For example, as illustrated inFIGS.1A and1B, the movement may be provided through an actuator assembly52that may be coupled with a static support54. In some embodiments, the actuator assembly52may include a vertical actuator56between the stage18and the static support54that allows for movement of the stage18in a first, vertical direction (e.g., along the Z-axis direction). The actuator assembly52may additionally or alternatively include a lateral actuator58between the stage18and the vertical actuator56and/or the static support54that allows for movement in a second, horizontal direction (e.g., along the X-axis direction and/or the Y-axis direction). In some embodiments, the vertical actuator56may be operably coupled with the lateral actuator58such that the stage18and vertical actuator56move along the lateral actuator58simultaneously. The actuator assembly52may include any device practicable of moving the stage18in the first and/or second direction, such as ballscrew electric actuators, linear electric actuators, pneumatic cylinders, hydraulic cylinders, delta drives, belt systems, or any other practicable device.

The radiant energy device20may be configured as any device or combination of devices operable to generate and project radiant energy at the resin R in a suitable pattern and with a suitable energy level and other operating characteristics to cure the resin R during the build process. For example, as shown inFIGS.1A and1B, the radiant energy device20may include a projector60, which may generally refer to any device operable to generate a radiant energy image of suitable energy level and other operating characteristics to cure the resin R. As used herein, the term “patterned image” refers to a projection of radiant energy including an array of one or more individual pixels. Non-limiting examples of patterned image devices include a DLP projector or another Digital Micromirror Device (DMD), a two-dimensional array of LEDs, a two-dimensional array of lasers, and/or optically addressed light valves. In the illustrated example, the projector60includes a radiant energy source62, such as a UV lamp, an image forming apparatus64operable to receive a source beam66from the radiant energy source62and generate a grid78or pixelated image to be projected onto the surface of the resin R, and optionally focusing optics70, such as one or more lenses. In some example embodiments, the pixels may have dimensions in the range of 10-100 micrometers (m).

The image forming apparatus64may include one or more mirrors, prisms, and/or lenses and is provided with suitable actuators, and arranged so that the source beam66from the radiant energy source62can be transformed can be transformed into the grid78in an X-Y plane coincident with the surface of the resin R. In the illustrated example, the image forming apparatus64may be a DMD. The projector60may incorporate additional components, such as actuators, mirrors, etc. configured to selectively move the image forming apparatus64or another part of the projector60with the effect of rastering or shifting the location of the grid78on the resin surface30. Stated another way, the grid78may be moved to various grid positions. The radiant energy device20can project the grid78onto the resin R to cure various portions of the resin R to form the component12layer-by-layer. As will be explained in greater detail herein, the apparatus10may be controlled to ensure that the grid78is intelligently shifted to align with the features associated with a layer to be built, thereby ensuring component quality and/or consistency as well as build efficiency.

In some further embodiments, the radiant energy device20can include multiple projectors. For instance, as depicted inFIG.1A, the radiant energy device20can include the projector60, or first projector, as well as a second projector74. The projector74can include all the features of projector60, for example. In some embodiments, the projector60can be a larger projector providing coarser resolution (relative to the second projector74) and can be fixed to cover the full desired printable footprint. The second projector74can be a smaller projector providing finer resolution (relative to the projector60), and optionally, can be movable to print fine features where needed. Such printers may print features within the same print area, and in some instances, at different resolutions.

In some other embodiments, the radiant energy device20may include a “scanned beam apparatus” used herein to refer generally to any device operable to generate a radiant energy beam of suitable energy level and other operating characteristics to cure the resin R and to scan the beam over the surface of the resin R in a desired pattern. For example, the scanned beam apparatus can include a radiant energy source62and a beam steering apparatus. The radiant energy source62may include any device operable to generate a beam of suitable power and other operating characteristics to cure the resin R. Non-limiting examples of suitable radiant energy sources62include lasers or electron beam guns.

Optionally, the modules of the apparatus10may be surrounded by a housing73, which may be used to provide a shielding or inert gas (e.g., a “process gas”) atmosphere using gas ports82. Optionally, pressure within the housing73could be maintained at a desired level greater than or less than atmospheric. Optionally, the housing73could be temperature and/or humidity controlled. Optionally, ventilation of the housing73could be controlled based on factors such as a time interval, temperature, humidity, and/or chemical species concentration. In some embodiments, the housing73can be maintained at a pressure that is different than an atmospheric pressure.

The apparatus10can include or may be operably coupled with a computing system110. The computing system110inFIG.1Ais a generalized representation of the hardware and software that may be implemented to control the operation of the apparatus10, including some or all of the stage18, the drive system28, the radiant energy device20, the actuator assembly52, actuators, and the various parts of the apparatus10described herein. The computing system110may be embodied, for example, by software running on one or more processors embodied in one or more devices such as a programmable logic controller (“PLC”) or a microcomputer. Such processors may be coupled to process sensors and operating components, for example, through wired or wireless connections. The same processor or processors may be used to retrieve and analyze sensor data for statistical analysis and for feedback control. Numerous aspects of the apparatus10may be subject to closed-loop control.

With reference now toFIGS.1and2,FIG.2provides a block diagram of a control system100of the additive manufacturing apparatus10ofFIG.1A. The control system100can include the computing system110as well as one or more controllable devices120, such as the stage18, the drive system28, the radiant energy device20, the actuator assembly52, and other controllable components of the apparatus10described herein. The computing system110can include one or more processors112and one or more memory devices114. Generally, the control system100is operable to control operation of the additive manufacturing apparatus10. Particularly, one or more of the controllable devices120can be controlled to shift a grid78of pixels from grid position to grid position so as to align the pixels of the grid78with features of the layer68. In this way, the features of the layer68can be flashed with radiant energy in an intelligent manner. InFIG.2, the grid78is shown being moved from one grid position to another.

The grid78can have a plurality of pixels and can be of a fixed geometry. The grid78can be moved or shifted with independent fine control (e.g. by a ¼, ⅓, or ½ shift, or by distance, e.g., 5 um, 10 um, etc.). The grid78is movable along the X-axis direction and/or the Y-axis direction. In some embodiments, optionally, the grid78may be rotated about an axis of rotation. By way of example,FIG.3depicts one example grid78of fixed spacing that may be projected by the additive manufacturing apparatus10, or more particularly, by the radiant energy device20thereof. As shown, the grid78has a plurality of pixels. Specifically, the grid78ofFIG.3includes pixels arranged in rows m and columns n. The pixels of grid78include pixels P11, P12, P13, and P14arranged within a first row, pixels P21, P22, P23, and P24arranged within a second row, pixels P31, P32, P33, and P34arranged in a third row, and pixels P41, P42, P43, and P44arranged in a fourth row. While the grid78ofFIG.3has four rows and four columns, it will be appreciated that the grid78can have other suitable numbers of rows and/or columns. It will also be appreciated that the grid78need not have the same number of rows and columns. For instance, in some alternative implementations, the grid78may have ten rows and six columns. Also, in some embodiments, the grid78can have a non-traditional layout that is not in a traditional X-Y grid configuration.

As noted, the grid78projected by the additive manufacturing apparatus10may be shifted to a plurality of different grid positions. Particularly, the grid78may be shifted to any suitable position within an exposure area140or area of regard. The exposure area140can be any suitable size. The exposure area140may be practically limited by the hardware and arrangement of the additive manufacturing apparatus10. The grid78is movable along the X-axis direction and/or the Y-axis direction. The grid78can be moved by actuating one or more components of the additive manufacturing apparatus10, such as by actuating the projector64or optical components. InFIG.3, the exposure area140is shown having a rectangular shape. In other embodiments, the exposure area140can have other suitable shapes.

With reference now toFIGS.1,2, and3, to summarize the general control scheme for shifting the grid78, the one or more processors112of the computing system110can receive data150. The data150can include data associated with the layer to be printed, or layer data152. The layer data152can include or indicate a geometry of the layer to be printed. The layer data152can also include or indicate a geometry of layers adjacent to the present layer. Further, in some embodiments, the layer data152can include or indicate a geometry of all layers of the component12to be built. In addition, the data150received by the one or more processors112of the computing system110can include data associated with the grid, or grid data154. The grid data154can include or indicate a geometry of the grid. Further, the grid data154can include or indicate a present location of the grid78, e.g., in coordinates, an offset from a home grid position, a combination of the two, etc.

Based at least in part on the layer data152and the grid data154, the one or more one or more processors112of the computing system110can generate a layer build plan160. The layer build plan160can indicate a manner in which the grid78projected by the additive manufacturing apparatus10is to be shifted to one or more grid positions during printing of the layer68as well as which pixels of the grid78are to be flashed at each grid position. In addition, the layer build plan160can indicate the radiant energy intensity or “flash intensity” associated with each pixel that is flashed at a given grid position. Effectively, the layer build plan160provides instructions for shifting the grid78from one grid position to the next and instructions for which of the pixels of the grid78are to be flashed and at what flash intensity for a given grid position.

By way of example,FIG.4provides one example layer build plan160according to various aspects of the present disclosure. For this example, the layer build plan160includes two flashes or shots of radiant energy, including a first flash and a second flash. For the first flash, the layer build plan160instructs that the grid position that the grid78is to be positioned in is a first grid position X1, Y1. The pixels to be flashed at the first grid position X1, Y1 are pixels P11, P12, P21, and P22. Pixels P11, P12, P21, and P22are to be flashed at respective flash intensities I11, I12, I21, and I22, which can be the same or different flash intensities from one another. After flashing the noted pixels at the first grid position X1, Y1, the grid78is shifted to the second grid position X2, Y2 for the second flash or shot. For the second flash, the layer build plan160instructs that the grid position that the grid78is to be positioned in is second grid position X2, Y2. The pixels to be flashed at the second grid position X2, Y2 is pixel P13. Pixels P13is to be flashed at a flash intensity I13. It will be appreciated that the generated layer build plan160depicted inFIG.4is provided as an example and is not intended to be limiting. It will be appreciated that other generated layer build plans can have more than two flashes or shots and that various other pixels and flash intensities are possible. It will further be appreciated that a layer build plan can be generated for each layer of the component12.

Notably, with reference again toFIGS.1and2, the layer build plan160can be generated based at least in part on one or more optimization rules156in addition to the layer data152and the grid data154. The optimization rules156can be received as part of the data150. The optimization rules156can dictate or instruct how the layer build plan160is constructed, or rather, how the grid78is to be moved around and flashed to build the layer68. That is, the one or more optimization rules can include a set of rules that constrain and prioritize certain aspects of building up the layer. For instance, such optimization rules156can include, without limitation, rules associated with: minimizing the shifting distance from one grid position to the next, minimizing the number of shifts needed for printing the layer, avoiding or minimizing flashing overlap to prevent print through or uneven material properties, reducing the intensity at the overlap regions, and selecting the starting grid position as the position in which a greatest number of the plurality of the pixels of the grid78can be flashed at once to form at least part of the layer68with each subsequent grid position having less than or a same number of pixels of the grid78to be flashed at once. The priority that one optimization rule156takes over another can change as the number of flashes increases for a given layer. In this regard, each rule of the optimization rules156can have a rule priority associated therewith, which as noted, may vary as the number of flashes increases for a given layer.

As further shown inFIG.2, the data150received by the one or more processors112can include feedback data158. The feedback data158can include data from one or more sensors130or controllable devices120. The feedback data158can indicate, for example, the actual status, position, etc. of the various controllable devices120and/or the conditions associated with the apparatus10as captured by the one or more sensors130. The layer build plan160can be generated based at least in part on the feedback data158.

With the layer build plan160generated, the one or more one or more processors112of the computing system110can generate one or more control commands170that can be routed to the various controllable devices120of the apparatus10. In this way, the grid78may be shifted from grid position to grid position and the selected pixels of the grid78may be flashed at the designated grid position and at the desired flash intensity in accordance with the layer build plan160.

For instance, in one example aspect, the one or more processors112can cause the grid78to shift or remain in place in a first grid position in accordance with the layer build plan160. Specifically, the one or more control commands170can be routed to the one or more controllable devices120and the controllable devices120can shift the grid78to the first grid position. The one or more processors112can cause the radiant energy device20, which is represented inFIG.2as one of the controllable devices120, to flash one or more of the plurality of pixels of the grid78with the grid78positioned in the first grid position to form at least a part of the layer68. As noted, the optimization rules156can be set so that the first grid position can be a position in which a greatest number of the plurality of the pixels of the grid78can be flashed at once to form at least a part of the layer68.

The one or more processors112can cause the grid78to shift from the first grid position to a second grid position in accordance with the layer build plan160. For instance, inFIG.2the grid78is shown being shifted from the first grid position to the second grid position. The one or more control commands170can be routed to the one or more controllable devices120and the controllable devices120can shift the grid78from the first grid position to the second grid position. The one or more processors112can cause the radiant energy device20to flash one or more of the plurality of pixels of the grid78with the grid78positioned in the second grid position to form at least a part of the layer68. This process may iterate until the entirety of layer68is printed. The process noted above can be repeated for each layer of the component12to be printed. Example methods in which a grid may be shifted so that the layer or sections thereof can be flashed with radiant energy in an intelligent manner will be further described below with reference to methods200,200A,200B.

In some embodiments, the layer build plan160can be generated “on the fly” wherein a first layer is built up with a first generated build plan and then a second build plan is generated for a second layer to be built on the first layer based at least in part on the first build plan, the conditions during the build of the first layer, the current position of the grid78after building the first layer, etc., with this process repeating for each subsequent layer. In other embodiments, the layer build plan160can be generated as a file that includes build instructions or a build plan for each layer of the component, e.g., before any layers of the component are built. The file can be uploaded or stored on one or more memory devices of the computing system110, and one or more processors can execute the file to build the component.

FIG.5provides a flow diagram for a method200of operating an additive manufacturing apparatus in accordance with various aspects of the present disclosure. The method200can be used to operate the additive manufacturing apparatus10or any other suitable additive manufacturing apparatus. It should be appreciated that the example method200is discussed herein only to describe example aspects of the present subject matter and is not intended to be limiting. Reference will be made generally toFIGS.1through4below to provide context to the method200ofFIG.5.

At202, the method200includes receiving data. In some implementations, the data can include layer data indicating a geometry of a layer of a component to be printed by an additive manufacturing apparatus. For instance, the one or more processors112of the computing system110of the additive manufacturing apparatus10can receive layer data152as part of the data150as depicted inFIG.2. The layer data152can be uploaded to the computing system110, e.g., via a suitable 3D data file, and ultimately received by the one or more processors112. The layer data152can include all relevant information relating to the geometry of the layer to be built, including the thickness, width, length, as well as other features of the layer to be printed. In some implementations, in addition to the geometry of the present layer, the layer data152can include or indicate a geometry of one or more layers adjacent to the present layer. In some implementations, in addition to the geometry of the present layer, the layer data152can include or indicate a geometry of each layer of the component12to be printed by the additive manufacturing apparatus10.

Further, at202, the data150received can include grid data154. For instance, the one or more processors112of the computing system110of the additive manufacturing apparatus10can receive the grid data154as depicted inFIG.2. The grid data154can include or indicate a geometry of the grid78. Further, the grid data154can include or indicate a present location of the grid78, e.g., in coordinates, an offset from a home grid position, etc.

In addition, at202, the data150received can include one or more optimization rules156. The one or more optimization rules156can dictate how the layer build plan160is constructed at206or214as will be explained further below. As noted, optimization rules156can include, without limitation, rules associated with: minimizing the shifting distance from one grid position to the next, minimizing the number of shifts needed for printing the layer, avoiding or minimizing flashing overlap to prevent print through or uneven material properties, reducing the intensity at the overlap regions, and selecting the starting grid position as the position in which a greatest number of the plurality of the pixels of the grid78can be flashed at once to form at least part of the layer with each subsequent grid position having less than or a same number of pixels of the grid78to be flashed at once. The priority that one optimization rule takes over another can change as the number of flashes increases for a given layer. The data150received can also include feedback data158as noted above.

At204, the method200includes determining whether the layer to be printed may be printed in a single flash or shot using the grid of fixed spacing projected by the additive manufacturing apparatus. For instance, the one or more processors112of the computing system110can determine whether the layer to be printed may be printed in a single flash using the grid78. That is, the one or more processors112can determine whether the grid78of fixed spacing will align “well” to the features of the layer68to be printed (e.g., to cover a preconfigured percentage of the cross-sectional area of the layer68), regardless of where the grid78might need to be positioned within the exposure area140.

The one or more processors112can make such a determination based at least in part on the geometry of the layer to be printed and the geometry of the grid78of fixed spacing. In some implementations, the one or more processors112can determine whether the layer68to be printed may be printed in a single flash using the grid78by determining whether one or more pixels of the grid78can be aligned to the features of the layer68and subsequently flashed so that the layer68is formed within a predetermined tolerance of a design specification associated with the layer68. In other implementations, the one or more processors112can determine whether the layer68to be printed may be printed in a single flash using the grid78by determining whether one or more pixels of the grid78can be aligned to the features of the layer68and subsequently flashed so that a predetermined percentage of an area of the layer68is formed, e.g., 95%. In some implementations, the one or more processors112can determine whether the layer68to be printed may be printed in a single flash using the grid78by determining whether one or more pixels of the grid78can be aligned to the features of the layer68and subsequently flashed so that the layer68is formed within a predetermined tolerance of a design specification of the layer68and so that a predetermined percentage of an area of the layer68is formed. When the one or more processors112determine that the layer68to be printed may be printed in a single flash or shot using the grid78, the method200proceeds to206as depicted inFIG.5.

At206, the method200includes generating the layer build plan160. The layer build plan160generated at206indicates a manner in which the grid78projected by the additive manufacturing apparatus10is to be shifted to an optimal grid position for the single flash, as well as which pixels of the grid78are to be flashed at the optimal grid position. In addition, the layer build plan160generated at206can indicate the radiant energy intensity or “flash intensity” associated with each pixel that is flashed at the optimal grid position. The layer build plan160can be generated by the one or more processors based at least in part on the geometry of the layer68, the geometry of the grid78, and the current position of the grid78, as well as any applicable optimization rules156.

By way of example,FIG.6depicts a layer68to be printed by the grid78. In this example, the layer68is a rectangle located in the upper right portion of the exposure area140. Based on the known geometry of the layer68and the known geometry of the grid78, which can include the known size of the pixels of the grid78, the one or more processors112of the computing system110can determine at204that the layer68to be printed may be printed in a single flash or shot using the grid78. Accordingly, at206, the one or more processors112of the computing system110can generate the layer build plan160that indicates the manner in which the grid78is to be moved or shifted to the optimal grid position for flashing the layer68in a single flash. The layer build plan160can also indicate which pixels of the grid78are to be flashed when the grid78is shifted to the optimal grid position as well as their respective flash intensities. Thus, the layer build plan160generated at206can include the same or similar information as the layer build plan160depicted inFIG.4, except of course that there is only a single flash number for the layer build plan160generated at206for the layer68ofFIG.6.

The layer build plan160can also be generated based at least in part on the one or more optimization rules156. For instance, for this example, the optimization rules156considered by the one or more processors112can include a first rule of first priority that instructs that the grid78is to be shifted so that the pixels of the grid78align as close as possible to the features of the layer68. The one or more processors112can also consider a second rule of second priority, the second priority being a lower priority than the first priority, which instructs that a grid shift distance is to be minimized. The one or more processors112can further consider other optimization rules156as well. The optimal grid position can be determined based at least in part on the optimization rules156.

Accordingly, for this example, the layer build plan160is generated so that instructions are provided to shift the grid78from its current position shown inFIG.6to the optimal grid position shown inFIG.7. The optimal grid position is determined based at least in part on the optimization rules156and their respective priorities. Particularly, for this example, as the first rule and the second rule noted above can both be satisfied, the optimal grid position is selected so that the pixels of the grid78align as close as possible to the features of the layer68and so that a grid shift distance is minimized, or the distance the grid78is shifted from its current position to the optimal grid position.

At208, the method200includes positioning (e.g., maintaining the grid in place or shifting) the grid to the optimal grid position in accordance with the layer build plan. For instance, the one or more processors112can cause the one or more controllable devices120to move or shift the grid78from its position inFIG.6to the optimal grid position shown inFIG.7. Particularly, the one or more processors112can generate one or more control commands170based at least in part on the layer build plan160generated at206. The generated control commands170can be routed to the one or more controllable devices120and such controllable devices120can shift the grid78to the optimal grid position. As one example, the image forming apparatus64may be controlled in accordance with the control commands170so that the grid78is shifted to the optimal grid position.

Continuing with the example,FIG.7depicts the grid78shifted to the optimal grid position. As shown, pixels P13, P14, P23, and P24of the grid78closely align with the features of the layer68and fill the area of the layer68. Moreover, while other combinations of pixels would also align with the features of the layer68as well, pixels P13, P14, P23, and P24of the grid78were selected as being the pixels to align with the layer68so as to minimize the shifting distance of the grid78.

At210, the method200includes flashing one or more of the plurality of pixels of the grid with the grid positioned in the optimal grid position to create the layer. For instance, the one or more processors112can cause the radiant energy device20of the additive manufacturing apparatus10to flash one or more of the plurality of pixels of the grid78. For example, as shown inFIG.7, the one or more processors112can cause the radiant energy device20to flash pixels P13, P14, P23, and P24of the grid78at their respective flash intensities to create layer68. The other pixels of the grid78would not be flashed. Accordingly, the layer68is formed having a rectangular shape.

At212, the method200ends and either the next layer is printed, e.g., using method200, or if the layer68is the last layer, the component12is completed and printing may cease.

As noted above, in some instances, the layer data152received by the one or more processors112can include data150associated with a geometry of a layer adjacent to the present layer to be printed. For instance, the layer data152can include data indicating a geometry of a layer to be printed immediately after the present layer. In such implementations, in generating the layer build plan160at206, the optimization rules156considered by the one or more processors112can include a first rule of first priority that instructs that the grid78is to be shifted so that the pixels of the grid78align as close as possible to the features of the layer68. The one or more processors112can also consider a second rule of second priority, the second priority being a lower priority than the first priority, which instructs that, if possible, the grid78is to be shifted so as to eliminate the need to shift the grid78from one layer to the next. The one or more processors112can further consider a third rule of third priority, the third priority being a lower priority than the second priority, which instructs that a grid shift distance is to be minimized from the current position of the grid78to the optimal grid position.

By way of example and with reference now toFIGS.6,8, and9, as noted, the layer build plan160is generated at206so that instructions are provided to shift the grid78from its current position shown inFIG.6to the optimal grid position. The optimal grid position can be determined by the one or more processors112based at least in part on the optimization rules156and their respective priorities. Accordingly, for this example, the first rule may be satisfied as the pixels of the grid78may be shifted so that the pixels of the grid78align well to the features of the layer68, e.g., so that the pixels aligned with the features of the layer68align with the features so that, when the pixels are flashed, the layer is formed within a predetermined tolerance of a design specification of the layer68and/or so that a predetermined percentage of an area of the layer68is formed, e.g., 90%.

In this example, there are a number of possible pixel combinations that may achieve this result. For instance, as noted above and depicted inFIG.7, pixels P13, P14, P23, and P24of the grid78may align well with the features of layer68. However, in considering the second rule, the one or more processors112can determine that it is possible to eliminate the need to shift the grid78from one layer to the next. That is, the one or more processors112may determine that it may be possible to flash one, some, or all pixels of the grid78with the grid78in a particular grid position to create the present layer68and then to flash one, some, or all pixels of the grid78with the grid78in the same grid position to create a subsequent layer or at least a part thereof.

For instance, suppose the current or present layer68to be printed is shown inFIG.8while the next or subsequent layer68B to be printed is shown inFIG.9. As shown, the grid78can be moved or shifted so that the pixels of the grid78are aligned well with the features of the present layer68and so that the pixels of the grid78are aligned well with the features of the subsequent layer68B. More specifically, the grid78can be moved or shifted to a grid position so that pixels P12, P13, P22, and P23are aligned with the features of the present layer68as shown inFIG.8. As depicted inFIG.9, this strategic grid position allows for pixels P11, P12, P13, P14, P21, P22, P23, and P24to align with the features of the subsequent layer68B. In this regard, the grid78need not be shifted after flashing the present layer68and before flashing the subsequent layer68B.

Although the grid78is shifted a slightly greater distance from its position inFIG.6to its position depicted inFIGS.8and9than the distance from its position inFIG.6to its position inFIG.7, the priority of minimizing the shifts between layers is of a higher priority in this example than minimizing the shifting distance of the grid78from its current position to align with the features of the present layer68. Accordingly, the optimal grid position is determined as the position of the grid78shown inFIGS.8and9for this example. With the grid78shifted to the optimal grid position as shown inFIGS.8and9, pixels P12, P13, P22, and P23of the grid78can be flashed to form the present layer68and pixels P11, P12, P13, P14, P21, P22, P23, and P24can be flashed to form the subsequent layer68B without need to shift the grid78. In this way, the grid78is shifted intelligently to provide improved printing efficiency.

Returning now toFIG.5, when the one or more processors determine that the layer to be printed may not be printed in a single flash or shot using a grid of fixed spacing projected by the additive manufacturing apparatus as determined at204, the method200proceeds to214.

At214, the method200includes generating a layer build plan that indicates a manner in which the grid projected by the additive manufacturing apparatus is to be shifted from grid position to grid position during printing of the layer. The generated layer build plan160can also include or indicate which of the pixels of the grid78are to be flashed and at what level or flash intensity the pixels are to be flashed. For instance, the one or more processors112of the computing system110can generate the layer build plan160based at least in part on the geometry of the layer68to be printed, the geometry of the grid78, including the geometry and arrangement of the pixels of the grid78, and in some instances, one or more optimization rules156. In accordance with the layer build plan generated at214, the grid can be shifted to a grid position at216, one or more pixels of the grid can be flashed at218with the grid78positioned in or shifted to the grid position, and the grid78can be iteratively shifted and flashed at one or more subsequent grid positions in an intelligent manner. Actions216and218may iterate in accordance with the layer build plan160generated at214until the one or more processors112determine at220that the layer68is completed.

By way of example,FIGS.10through16depict a sequence of a layer68being formed by flashing certain pixels of grid78projected by apparatus10. For this example, the layer68to be printed has an oval shape as outlined by its perimeter71. The layer68to be printed is located generally in the middle of the exposure area140. Based on the known geometry of the layer68and the known geometry of the grid78, which can include the known geometry of the pixels of the grid78, the one or more processors of the computing system110can determine at204of the method200that the layer68to be printed may not be printed in a single flash or shot using the grid78. For instance, the one or more processors112can determine that the one or more pixels of the grid78cannot be aligned to the features of the layer68and the pixels subsequently flashed so that the layer68is formed within a predetermined tolerance of a design specification of the layer68and/or so that a predetermined percentage of an area of the layer68is formed. In such an instance, the method200proceeds to214, as noted above.

Accordingly, at214, the one or more processors112of the computing system110can generate the layer build plan160that indicates a manner in which the grid78is to be shifted during printing of the layer68. The layer build plan160can also indicate which pixels of the grid78are to be flashed when the grid78is shifted to a particular grid position as well as the flash intensity at which the pixels are to be flashed. Thus, the layer build plan160generated at214can include the same or similar information as the layer build plan160depicted inFIG.4.

The layer build plan160generated at214can also be generated based at least in part on the one or more optimization rules156. For instance, for this example, the optimization rules156considered by the one or more processors112can include a first rule of first priority that instructs that the grid78is to be shifted or positioned so that the starting grid position or first grid position is a position in which a greatest number of the plurality of the pixels of the grid78can be flashed “full on” at once or in a single flash to form a first part of the layer68. As used herein, a given pixel is “full on” or substantially within a perimeter of a layer to be printed when a total area of the given pixel is within the perimeter of the layer68by a predetermined area percentage. In some implementations, the predetermined area percentage is seventy-five percent (75%). In other implementations, the predetermined area percentage is eighty-five percent (85%). In further implementations, the predetermined area percentage is ninety percent (90%). In yet other implementations, the predetermined area percentage is ninety-five percent (95%). In some other implementations, the predetermined area percentage is one hundred percent (100%). The predetermined area percentage may change from layer to layer or may even be different within a same layer, e.g., more focus or intensity in high definition areas of a given layer. The predetermined area percentage may also remain the same from layer to layer or within a same layer.

The first rule further instructs that each subsequent grid position is a position in which the number of pixels of the grid78to be flashed at once to form part of the layer68is equal to or less than the greatest number of the plurality of pixels of the grid78that can be flashed during the flashing of the previous layer68. The one or more processors112can consider other optimization rules156as well, such as minimizing the shifting distance between flashes, minimizing the overall number of shifts, minimizing flash overlap, minimizing the overlap of flashed areas, or some combination of the foregoing.

Thus, for this example, the layer build plan160is generated at214so that instructions are provided to shift the grid78from its current grid position P-0 shown inFIG.10to a first grid position P-1 depicted inFIG.11. For instance, the layer build plan160is generated so that, when the layer build plan160is executed, the grid78is shifted half a pixel to the right along the X-axis direction. As shown inFIG.11, in accordance with the optimization rules, the first grid position P-1 is a position in which the greatest number of the plurality of the pixels of the grid78(which is four pixels in this instance) can be flashed at once to form a first part of the layer68. For this example, pixels P22, P23, P31, and P32of the grid78equate to the greatest number of the plurality of the pixels of the grid78that can be flashed full on at once to form a first part of the layer68. While the grid78could have remained in the current grid position P-0 or been shifted so that some other combination of four pixels could align with the features of the layer68to be flashed at once to form a first part of the layer68, the one or more processors112have generated the layer build plan160considering optimization rules156instructing that a minimum number of shifts be made to form the layer68and that the shifting distance be minimized all while forming the layer68within a predetermined tolerance of a design specification of the layer68and/or so that a predetermined percentage of an area of the layer68is formed. Accordingly, in this example, the layer build plan160generated at214instructs that the grid is to be shifted to the first grid position P-1 at216and that pixels P22, P23, P31, and P32of the grid78are to be flashed at218.

After pixels P22, P23, P31, and P32of the grid78are flashed at218while the grid78is in the first grid position P-1 to form a first part or portion of the layer68as shown inFIG.11, at220, the one or more processors112determine that the layer68is not complete. Thus, in accordance with the layer build plan160generated at214, the grid78is shifted at216from the first grid position P-1 depicted inFIG.11to a second grid position P-2 depicted inFIG.12. For instance, the layer build plan160is generated so that, when the layer build plan160is executed, the grid78is shifted down a third of a pixel along the Y-axis direction. When in the second grid position P-2, pixels P12, P21, P23, and P31of the grid78are to be flashed at218to form at least a part of the layer68, e.g., a second part of the layer68.

Once pixels P12, P21, P23, and P31of the grid78are flashed at218while the grid78is in the second grid position P-2 to form a second part or portion of the layer68, at220, the one or more processors112determine that the layer68is not complete. Thus, in accordance with the layer build plan160generated at214, the grid78is shifted at216from the second grid position P-2 depicted inFIG.12to a third grid position P-3 depicted inFIG.13. For instance, the layer build plan160is generated so that, when the layer build plan160is executed, the grid78is shifted down a third of a pixel along the Y-axis direction and to the left a quarter of a pixel along the X-axis direction. When in the third grid position P-3, pixels P12, P13, P21, P23, and P32of the grid78are flashed at218to create a third part or portion of the layer68.

After pixels P12, P13, P21, P23, and P32of the grid78are flashed at218while the grid78is in the third grid position P-3 to form a third part or portion of the layer68, at220, the one or more processors112determine at220that the layer68is not complete. Thus, in accordance with the layer build plan160generated at214, the grid78is shifted at216from the third grid position P-3 depicted inFIG.13to a fourth grid position P-4 depicted inFIG.14. For instance, the layer build plan160is generated so that, when the layer build plan160is executed, the grid78is shifted to the left a third of a pixel along the X-axis direction. When in the fourth grid position P-4, pixels P12and P32of the grid78are flashed at218to create a fourth part or portion of the layer68.

Further, once pixels P12and P32of the grid78are flashed at218while the grid78is in the fourth grid position P-4 to form the fourth part or portion of the layer68, at220, at220, the one or more processors112determine that the layer68is not complete. Thus, in accordance with the layer build plan160generated at214, the grid78is shifted at216from the fourth grid position P-4 depicted inFIG.14to a fifth grid position P-5 depicted inFIG.15. For instance, the layer build plan160is generated so that, when the layer build plan160is executed, the grid78is shifted upward a third of a pixel along the Y-axis direction. When in the fifth grid position P-5, pixels P13and P33of the grid78are flashed at218to create a fifth part or portion of the layer68.

After iterating216and218of the method200until the layer68is formed within a predetermined tolerance of a design specification of the layer68and/or so that a predetermined percentage of an area of the layer68is formed and/or until some other criteria is met as determined at220, the one or more processors112can repeat method200for the next layer and/or until the component12is fully formed. As depicted inFIG.16, due to the intelligent shifting of the grid78and flashing of select pixels in accordance with the layer build plan160generated at214, the built-up layer68is formed to specification. Advantageously, method200may provide better control over edges and edge placement compared to conventional printing techniques. Particularly, building up a layer using the method200may provide better “resolution” at the edges or perimeter of the layer compared to a layer formed using conventional techniques. For instance,FIG.17depicts a layer68PA built up to the same specification as the layer68ofFIG.16(as represented by the perimeter71inFIG.17). Notably, the layer68ofFIG.16has much better resolution at the perimeter71than does the layer68PA built up using a conventional technique.

In accordance with another example implementation of method200, a layer of a component can be printed by the apparatus10using a bulk flash and trace technique. With reference now toFIGS.1,2, and18through23,FIG.18is a flow diagram for a method200A in which a bulk flash and trace technique is used instead of the approach set forth in214through220depictedFIG.5.FIGS.19through23depict an example sequence of printing a layer in accordance with the method200A set forth inFIG.18.

After receiving data at202and determining that the layer to be printed cannot be printed in a single flash or shot using the grid of fixed spacing projected by the additive manufacturing apparatus at204, e.g., as provided above with reference to method200ofFIG.5, at222, the method200A includes generating a layer build plan. For instance, the one or more processors112of the computing system110can generate the layer build plan160based at least in part on a geometry of the layer to be printed as derived from received layer data152, the geometry of the grid as derived from the received grid data154, and/or one or more optimization rules156. The layer build plan160can indicate instructions for printing the layer68in a bulk flash and trace technique. Particularly, the layer build plan160can indicate instructions for positioning the grid78so that a greatest number of a plurality of pixels of the grid are aligned “full on” within a perimeter71of the layer68to be printed; flashing the greatest number of the plurality of pixels of the grid78with radiant energy with the greatest number of the plurality of pixels aligned full on within the perimeter71of the layer68to form at least part of the layer68; tracing a pixel or a collection of pixels of the grid78around the perimeter71of the layer68; and flashing the pixel or collection of pixels with radiant energy as the pixel or collection of pixels is traced around the perimeter71of the layer68to form at least part of the layer68. The layer build plan160can also indicate the flash intensity at which the various pixels of the grid78are to be flashed.

The one or more optimization rules156considered by the one or more processors112in generating the layer build plan160at222can include, without limitation, rules for determining the tracing path of the pixel or collection of pixels to be traced around the perimeter71of the layer68, a number of times the pixel or collection of pixels are to be traced around the perimeter71of the layer68, a number of pixels to be traced around the perimeter71of the layer68(which may be based on the area between the perimeter71and the flashed “bulk area”, among other possible criteria), as well as other optimization rules.

At224, the method200A includes executing the layer build plan to build up or print the layer. As depicted inFIG.18, executing the layer build plan at224can include performing actions224A through224D. In executing the layer build plan160at224, the one or more processors112can generate one or more control commands170based at least in part on the generated layer build plan160. The generated one or more control commands170can be routed to one or more controllable devices120that may actuate, shift, or otherwise move the grid78and/or pixels thereof projected by the radiant energy device20in accordance with the layer build plan160.

At224A, in executing the layer build plan160generated at222, the method200A includes positioning the grid projected by the additive manufacturing apparatus so that a greatest number of a plurality of pixels of the grid are aligned full on within a perimeter of a layer to be printed by the additive manufacturing apparatus. For instance, the one or more processors112can cause the grid78projected by the radiant energy device20of the additive manufacturing apparatus10to shift or remain in place so that a greatest number of a plurality of pixels of the grid78are aligned full on within a perimeter71of the layer68to be printed.

By way of example, as depicted inFIG.19, the one or more processors112have positioned the grid78, either by keeping the grid78in place or by shifting the grid78, so that a greatest number of pixels of the grid78are aligned full on within a perimeter71of the layer68. Specifically, for this example implementation, the grid78is positioned so that pixels P22, P23, P32, and P33of the grid78are aligned full on within the perimeter71of the layer68to be printed. Pixels P22, P23, P32, and P33collectively form a “bulk flash area” or bulk area to be flashed in a single flash or shot. For this example implementation, in generating the layer build plan160at222, the one or more processors112determined that four pixels is the greatest number of pixels that may be aligned full on within the perimeter71, e.g., based at least in part on the geometry of the layer and the geometry of the pixels of the grid78. Accordingly, in accordance with the layer build plan160, the grid78is positioned as depicted inFIG.19. In addition, for this example implementation, the grid78is positioned not only so that the most full on pixels are aligned within the perimeter71of the layer68, but also so that the grid78is aligned as close as possible to being centered with respect to the layer68to be printed. Such instructions can be included as part of the optimization rules156used to generate the layer build plan at222.

At224B, the method200A includes flashing the greatest number of the plurality of pixels of the grid with radiant energy with the greatest number of the plurality of pixels aligned full on within the perimeter of the layer to form at least part of the layer. For instance, the one or more processors112can cause the radiant energy device20to flash the greatest number of the plurality of pixels of the grid78with the greatest number of the plurality of pixels aligned full on within the perimeter71of the layer68to form at least part of the layer68. As depicted inFIG.19, pixels P22, P23, P32, and P33are aligned full on within the perimeter71of the layer68and are flashed with radiant energy by the radiant energy device20. The flashing of pixels P22, P23, P32, and P33creates a flashed bulk area75. In creating the flashed bulk area75, a part of the layer68is formed. To complete printing of the layer68, as will be explained further below, one or more pixels are traced around the perimeter71of the layer68and flashed. Stated another way, one or more pixels are traced around the flashed bulk area75and flashed to complete printing of the layer68.

At224C, the method200A includes tracing a pixel of the plurality of pixels of the grid around the perimeter of the layer. For instance, the one or more processors112can cause a pixel of the plurality of pixels to trace around the perimeter71of the layer68. In some implementations, the entire grid78can be moved around so as to trace the pixel around the perimeter71. In other implementations, only one pixel (or a collection of pixels) is moved around so as to trace around the perimeter71. Further, in some implementations, the pixel is traced around a segment of the perimeter71. In yet other implementations, the pixel is traced around an entirety of the perimeter71.

Continuing with the example above, as shown inFIG.20, a tracing path TP for pixel PTis depicted. In this example implementation, the pixel PTis to be traced around the entire perimeter71of the layer68in accordance with the tracing path TP. Particularly, the pixel PTis to be traced from its starting position shown inFIG.20and is to be traced clockwise around the perimeter71along the tracing path TP as shown sequentially inFIGS.21,22, and23. The pixel PTtraces the perimeter71and returns to its position shown inFIG.20. For this implementation, the pixel PTis traced along the tracing path TP so that half an area of the pixel PTis positioned outward of the tracing path TP and half the area of the pixel PTis positioned inward of the tracing path TP. However, in other implementations, pixel PTcan be traced along the tracing path TP in other suitable manners. For instance, the pixel PTcan be traced along the tracing path TP so that a corner of the pixel PTis traced precisely over the tracing path TP.

Further, for this example implementation, in generating the layer build plan at222, the tracing path TP is set or determined so that the pixel PTis positioned at or at least partially outside of the perimeter71and so that the pixel PToverlaps the flashed bulk area at least in part as the pixel PTtraces along the entire the tracing path TP. In some implementations, the tracing path TP is set or determined so that the pixel PTis traced so that at least eighty percent of the pixel PTis positioned at or within the perimeter71of the layer68as the pixel PTis traced around. In this way, as the pixel PTis flashed at224D as explained more fully below, the outer edges or perimeter71of the layer68can be accurately formed.

At224D, the method200A includes flashing the pixel with radiant energy as the pixel is traced around the perimeter of the layer to form at least part of the layer. For instance, the one or more processors112can cause the radiant energy device20to flash the pixel PTas the pixel PTis traced around the perimeter71of the layer68to form at least part of the layer, e.g., the outer periphery of the layer68. Continuing with the example noted above, the one or more processors112can cause the radiant energy device20to flash the pixel PTas the pixel PTis traced along the tracing path TP shown inFIG.20, which corresponds to or has the same general shape as the perimeter71of the layer68.

In some implementations, the one or more processors112can cause the pixel PTto trace around the perimeter71of the layer in a continuous motion at224C. For instance, the one or more processors can cause the pixel PTtrace in a continuous motion along the tracing path TP, with the starting position of the pixel PTbeing shown inFIG.20, and after tracing along the tracing path TP, the ending position of the pixel PTalso being the position of the pixel PTshown inFIG.20. In such implementations, at224D, the one or more processors112can cause the radiant energy device20to continuously flash the pixel PTas the pixel PTis traced in the continuous motion around the perimeter71of the layer68to form at least part the layer68.

In yet other implementations, when the one or more processors112cause the pixel PTto trace around the perimeter71of the layer in a continuous motion at224C, at224D, the one or more processors112can cause the radiant energy device20to periodically flash the pixel PTas the pixel PTis traced in the continuous motion around the perimeter71of the layer68to form at least part of the layer. For example, the one or more processors112can cause the radiant energy device20to periodically flash the pixel PTas the pixel PTis traced in the continuous motion around the perimeter71of the layer68every tenth of a second, every half second, every second, every two seconds, etc.

In some other implementations, when the one or more processors112cause the pixel PTto trace around the perimeter71of the layer in a continuous motion at224C, at224D, the one or more processors112can cause the radiant energy device20to only flash the pixel PTas the pixel PTis traced in the continuous motion around the perimeter71of the layer68when a target condition is met. For instance, the one or more processors112cause the radiant energy device20to flash the pixel PTas the pixel PTis traced around the perimeter71of the layer68only when a threshold area of the pixel PTis positioned within the perimeter71of the layer68. In some implementations, the threshold area of the pixel PTis fifty percent (50%) of an area of the pixel PT. In other implementations, the threshold area of the pixel PTis eighty percent (80%) of an area of the pixel PT. In yet other implementations, the threshold area of the pixel PTis ninety-five percent (95%) of an area of the pixel PT.

In other implementations, when the one or more processors112cause the pixel PTto trace around the perimeter71of the layer in a continuous motion at224C, at224D, the one or more processors112can cause the radiant energy device20to only flash the pixel PTas the pixel PTis traced in the continuous motion around the perimeter71of the layer68when the pixel PTis at a predetermined discrete position. There can be multiple predetermined discrete positions positioned along the tracing path TP. By way of example, as the pixel PTis being traced around the perimeter71of the layer68along the tracing path TP, when the pixel PTis positioned at a first predetermined discrete position, e.g., the position of the pixel PTinFIG.20, the pixel PTis flashed. When the pixel PTis positioned at a second predetermined discrete position, e.g., the position of the pixel PTinFIG.21, the pixel PTis flashed once again. When the pixel PTis positioned at a third predetermined discrete position, e.g., the position of the pixel PTinFIG.22, the pixel PTis flashed yet again. Finally, when the pixel PTis positioned at a fourth predetermined discrete position, e.g., the position of the pixel PTinFIG.23, the pixel PTis flashed again. It will be appreciated that any suitable number of predetermined discrete positions are possible. The one or more processors112can determine the predetermined discrete positions based at least in part on the unflashed area between the flashed bulk area75and the perimeter71, among other possible criteria and/or constraints.

In some alternative implementations, at224C, the one or more processors112can cause the pixel PTto trace around the perimeter71of the layer in a discontinuous motion. For instance, the one or more processors can cause the pixel PTto trace in a discontinuous motion so that the pixel PTis stopped at predetermined discrete positions along the tracing path TP. In such implementations, at224D, the one or more processors112can cause the radiant energy device20to flash the pixel PTof the grid78only when the pixel PTis stopped at the predetermined discrete positions.

By way of example, the one or more processors112can cause the pixel PTto be moved or traced along the tracing path TP from its starting or first discrete position, e.g., a position of the pixel PTshown inFIG.20, to a second discrete position, e.g., a position of the pixel PTshown inFIG.21. When positioned at the second discrete position, the pixel PTcan be flashed so as to form a part of the layer68. Then, the one or more processors112can cause the pixel PTto trace along the tracing path TP from the second discrete position to a third discrete position, e.g., a position of the pixel PTshown inFIG.22. When positioned at the third discrete position, the pixel PTcan be flashed so as to form a part of the layer68. Next, the one or more processors112can cause the pixel PTto trace along the tracing path TP from the third discrete position to a fourth discrete position, e.g., a position of the pixel PTshown inFIG.23. When positioned at the fourth discrete position, the pixel PTcan be flashed so as to form a part of the layer68. Thereafter, the one or more processors112can cause the pixel PTto trace along the tracing path TP from the fourth discrete position to a final or fifth discrete position, e.g., a position of the pixel PTshown inFIG.20. When positioned at the fifth discrete position, the pixel PTcan be flashed so as to form a part of the layer68. Alternatively, the pixel PTcan be flashed initially prior to be being traced around the perimeter71of the layer68along the tracing path TP. Flashing the pixel PTonly at predetermined discrete positions can allow for intelligent and strategic printing of the layer68and may allow for more accurate formation of the geometry of the layer68.

In yet other implementations, when the one or more processors112cause the pixel PTto trace around the perimeter71of the layer in a discontinuous motion at224C, the one or more processors112can cause the radiant energy device20to flash the pixel PTof the grid78when the pixel PTis stopped at the predetermined discrete positions and when the pixel PTis shifted from one predetermined discrete position to another. In this way, a greater amount of radiant energy can be applied to specific portions of the layer68.

By way of example, the one or more processors112can cause the pixel PTto be moved or traced along the tracing path TP from its starting or first discrete position, e.g., a position of the pixel PTshown inFIG.20, to a second discrete position, e.g., a position of the pixel PTshown inFIG.21. As the pixel PTis traced from the first to the second discrete position the pixel PTcan be flashed so as to form a part of the layer68. Then, when the pixel PTis positioned at the second discrete position, the pixel PTcan be flashed so as to form a part of the layer68. Notably, when the pixel PTis stopped at the second discrete position, a greater amount of radiant energy can be applied at this location of the layer68than the locations between the first and second discrete positions, assuming the flash intensity remains constant. This may, for example, create different material properties at this location of the layer68in accordance with a design specification of the component12. After flashing the pixel PTat the second discrete position, e.g., for a predetermined time, the one or more processors112can cause the pixel PTto continue onward along the tracing path TP while flashing the pixel PTbetween discrete positions and while stopped at the discrete positions in a same or similar manner described above.

WhileFIGS.19through23and the accompanying text provide an example sequence of printing a layer using a bulk flash and trace technique in which only a single pixel is traced along a tracing path around the perimeter of a layer, in other implementations, more than one or a set of pixels can be traced along a tracing path around a flashed bulk area or perimeter of the layer. For instance,FIGS.24through28show an example sequence of printing a layer using a bulk flash and trace technique in which multiple or set of pixels is traced along a tracing path around the flashed bulk area or perimeter of a layer in accordance with the method200A set forth inFIG.18.

By way of example, as depicted inFIG.24, at224A the one or more processors112have positioned the grid78, either by keeping the grid78in place or by shifting the grid78, so that a greatest number of pixels of the grid78are aligned full on within a perimeter71of the layer68in accordance with the layer build plan160generated at222. Specifically, for this example implementation, the grid78is positioned so that pixels P22, P23, P32, and P33of the grid78are aligned full on within the perimeter71of the layer68to be printed. Pixels P22, P23, P32, and P33collectively form the bulk flash area75or bulk area to be flashed in a single flash or shot.

At224B, the one or more processors112can cause the radiant energy device20to flash the greatest number of the plurality of pixels of the grid78with the greatest number of the plurality of pixels aligned full on within the perimeter71of the layer68to form at least part of the layer68. As depicted inFIG.24, pixels P22, P23, P32, and P33are aligned full on within the perimeter71of the layer68and are flashed with radiant energy by the radiant energy device20. The flashing of pixels P22, P23, P32, and P33creates the flashed bulk area75.

At224C, the one or more processors112can cause a set of pixels to trace around the perimeter71along the tracing loop TP. For this example implementation, the set of pixels includes pixels PT1, PT2, PT3, and PT4. The set of pixels can be traced or moved along the tracing path TP around the perimeter71in any suitable manner, e.g., by moving one or more components of the radiant energy device20. The tracing path TP can be generated as described above. While four pixels are shown in the set of pixels, it will be appreciated that the set of pixels can include any suitable number of pixels greater than one. Further, for this implementation, the number of pixels within the set of pixels, which is four pixels in this example, is the same number of pixels as the number of pixels flashed at224B. In alternative implementations, the number of pixels within the set of pixels can be different than the number of pixels flashed at224B to form the flashed bulk area75. Moreover, while the pixels of the set of pixels collectively form a rectangular bulk area, it will be appreciated that the pixels of the set of pixels can collectively form other suitable shapes.

At224D, the one or more processors112can cause the set of pixels to be flashed by the radiant energy device20as the set of pixels is traced around the perimeter71to form at least part of the layer68. In some implementations, the one or more processors112can cause the radiant energy device20to flash the set of pixels as the set of pixels is traced around the perimeter71of the layer68only when a threshold area of a given pixel of the set of pixels is positioned within the perimeter71of the layer68. For example, the threshold area of the given pixel can be set at fifty percent (50%) of an area of the pixel. As another example, the threshold area of the given pixel can be set at eighty percent (80%) of an area of the pixel. As yet another example, the threshold area of the given pixel can be set at ninety-five percent (95%) of an area of the pixel.

By way of example, the set of pixels can be traced along the tracing path TP and flashed is depicted inFIGS.25through28. In some implementations, the set of pixels can be traced in a continuous motion along the tracing path TP. In such implementations, the set of pixels, or a subset thereof, can be flashed continuously as the set of pixels moves along the tracing path TP. The set of pixels can be traced along the tracing path TP at a continuous speed or at multiple speeds (i.e., at least two different speeds). For instance, the set of pixels may be moved at a first speed along a first portion of the tracing path (e.g., a straight portion) and at a second speed along a second portion of the tracing path (e.g., a curved portion), wherein the first speed is a greater speed than the second speed. In some other implementations, the set of pixels, or a subset thereof, can be flashed periodically as the set of pixels moves along the tracing path TP.

In yet other implementations, the set of pixels, or a subset thereof, can be flashed when one or more target conditions are met as the set of pixels moves along the tracing path TP. For instance, as one example, the one or more processors112can cause the radiant energy device20to flash a given pixel of the set of pixels when a threshold area of the given pixel is positioned within the perimeter71of the layer68. In some implementations, the threshold area of the given pixel can be set at fifty percent (50%) of an area of the given pixel. In other implementations, the threshold area of the pixel can be set at eighty percent (80%) of an area of the given pixel. In yet other implementations, the threshold area of the given pixel can be set at ninety-five percent (95%) of an area of the given pixel.

In some further implementations, the set of pixels can be traced collectively along the tracing path TP in a discontinuous motion. For instance, the one or more processors112can cause the set of pixels to stop at one or more predetermined discrete positions. In such implementations, the one or more processors112can cause the radiant energy device20to flash the set of pixels, or a subset thereof, when the set of pixels are stopped at the predetermined discrete positions. In some instances, the set of pixels can be flashed at only the predetermined discrete positions. In other instances, the set of pixels can be flashed at the predetermined discrete positions and when the set of pixels is shifted from one predetermined discrete position to another.

In some implementations, the set of pixels collectively have or define at least four outer corners. For instance, as shown inFIG.25, the set of pixels defines a first outer corner C1, a second outer corner C2, a third outer corner C3, and a fourth outer corner C4. In such implementations, when the one or more processors112cause the set of pixels to trace around the perimeter71of the layer68, the set of pixels are traced so that each one of the four outer corners is positioned at or outside of the perimeter71of the layer68, not necessarily simultaneously, at least at one discrete position along the tracing path TP. For instance, inFIG.25, the first outer corner C1is shown positioned outside of the perimeter71of the layer68. InFIG.26, the second outer corner C2is shown positioned outside of the perimeter71of the layer68. InFIG.27, the third outer corner C3is shown positioned outside of the perimeter71of the layer68. InFIG.28, the fourth outer corner C4is shown positioned outside of the perimeter71of the layer68.

In some implementations, the set of pixels are traced so that each corner is the sole one of the four corners that is positioned at or outside of the perimeter71at least at one particular position along the tracing path TP. For instance, inFIG.25, the set of pixels are positioned along the tracing path TP so that the first outer corner C1is the sole corner positioned outside of the perimeter71of the layer68. InFIG.26, the set of pixels are positioned along the tracing path TP so that the second outer corner C2is the sole corner positioned outside of the perimeter71of the layer68. InFIG.27, the set of pixels are positioned along the tracing path TP so that the third outer corner C3is the sole corner positioned outside of the perimeter71of the layer68. InFIG.28, the set of pixels are positioned along the tracing path TP so that the fourth outer corner C4is the sole corner positioned outside of the perimeter71of the layer68.

In accordance with another example implementation, a layer of a component can be printed by the apparatus10using a bulk flash and circle or spiral technique. With reference now toFIGS.1,2, and29through33,FIG.29is a flow diagram for a method200B in which a bulk flash and circle or spiral technique is used instead of the approach set forth in214through220of the method200depictedFIG.5.FIG.30depicts an example manner in which one or more pixels can be spiraled and flashed in accordance with the method200B set forth inFIG.29.FIGS.32and33depict an example in which one or more pixels can be circled and flashed in accordance with the method200B set forth inFIG.29.

After receiving data at202and determining that the layer to be printed cannot be printed in a single flash or shot using the grid of fixed spacing projected by the additive manufacturing apparatus at204as provided above with reference to the method200ofFIG.5, at232, the method200B includes generating a layer build plan. For instance, the one or more processors112of the computing system110can generate the layer build plan160based at least in part on a geometry of the layer to be printed as derived from the received layer data152, the geometry of the grid derived from the received grid data154, and/or one or more optimization rules156. The layer build plan160can indicate instructions for printing the layer in a bulk flash and spiral or circle technique. Particularly, the layer build plan160can indicate instructions for positioning the grid so that a greatest number of a plurality of pixels of the grid78are aligned “full on” within a perimeter71of the layer68to be printed; flashing the greatest number of the plurality of pixels of the grid78with radiant energy with the greatest number of the plurality of pixels aligned full on within the perimeter71of the layer68to form at least part of the layer68; moving a pixel of the plurality of pixels of the grid78in a circular motion or a spiral motion around a predefined point; and flashing the pixel with radiant energy as the pixel is moved in the circular motion or the spiral motion around the predefined point P to form at least part of the layer68. The layer build plan160can also indicate the flash intensity at which the various pixels of the grid78are to be flashed.

The one or more optimization rules156considered by the one or more processors112in generating the layer build plan160at232can include, without limitation, rules for determining the spiral path or circular path of the pixel or collection of pixels to be moved around the predefined point, a number of times the pixel or collection of pixels are to be moved around the predefined point, a number of pixels to be moved around the predefined point, the number and location of the predefined points, as well as other optimization rules.

At234, the method200B includes executing the layer build plan to build up or print the layer. As depicted inFIG.29, executing the layer build plan at234can include performing actions234A through234D. In executing the layer build plan160at234, the one or more processors112can generate one or more control commands170based at least in part on the generated layer build plan160. The generated one or more control commands170can be routed to one or more controllable devices120that may actuate, shift, or otherwise move the grid and/or pixels thereof projected by the radiant energy device20in accordance with the layer build plan160.

At234A, in executing the layer build plan160generated at232, the method200B includes positioning the grid projected by an additive manufacturing apparatus so that a greatest number of a plurality of pixels of the grid are aligned full on within a perimeter of a layer to be printed by the additive manufacturing apparatus. For instance, the one or more processors112can cause the grid78projected by the radiant energy device20of the additive manufacturing apparatus10to shift or remain in place so that a greatest number of a plurality of pixels of the grid78are aligned full on within a perimeter71of the layer68to be printed.

By way of example, as depicted inFIG.30, the one or more processors112have positioned the grid78, either by keeping the grid78in place or by shifting the grid78, so that a greatest number of pixels of the grid78are aligned full on within a perimeter71of the layer68. Specifically, for this example implementation, the grid78is positioned so that pixels P22, P23, P32, and P33of the grid78are aligned full on within the perimeter71of the layer68to be printed. Pixels P22, P23, P32, and P33collectively form a “bulk area” to be flashed in a single flash or shot. For this example implementation, in generating the layer build plan160at232, the one or more processors112determined that four pixels is the greatest number of pixels that may be aligned full on within the perimeter71, e.g., based at least in part on the geometry of the layer and the geometry of the pixels of the grid. Accordingly, in accordance with the layer build plan160, the grid78is positioned as depicted inFIG.30. In addition, for this example implementation, the grid78is positioned not only so that the most full on pixels are aligned within the perimeter71of the layer68, but also so that the grid78is aligned as close as possible to being centered with respect to the layer68to be printed. Such instructions can be included as part of the optimization rules156used to generate the layer build plan at232.

At234B, the method200B includes flashing the greatest number of the plurality of pixels of the grid with radiant energy with the greatest number of the plurality of pixels aligned full on within the perimeter of the layer to form at least part of the layer. For instance, the one or more processors112can cause the radiant energy device20to flash the greatest number of the plurality of pixels of the grid78with the greatest number of the plurality of pixels aligned full on within the perimeter71of the layer68to form at least part of the layer68. As depicted inFIG.30, pixels P22, P23, P32, and P33are aligned full on within the perimeter71of the layer68to be built and are flashed with radiant energy by the radiant energy device20. The flashing of pixels P22, P23, P32, and P33creates a flashed bulk area75. To complete printing of the layer68, as will be explained further below, one or more pixels are moved around one or more predefined points in a circular or spiral motion and flashed.

At234C, the method200B includes moving a pixel of the plurality of pixels of the grid in a circular motion or a spiral motion around a predefined point. For instance, the one or more processors112can cause a pixel of the plurality of pixels of the grid78to be moved in a circular motion or a spiral motion around a predefined point. In some implementations, the entire grid78can be moved around so as to move the pixel around the predefined point. In other implementations, only the pixel is moved around the predefined point without moving the entire grid78. Further, in some implementations, the pixel can be one pixel of a set of pixels. In this regard, a set of pixels can be moved in a circular motion or a spiral motion around a predefined point. In some implementations, the pixel can be moved in a circular motion or a spiral motion around a predefined point in a continuous motion. In other implementations, the pixel can be moved in a circular motion or a spiral motion around a predefined point in a discontinuous motion, e.g., stopping at predetermined discrete positions.

By way of example, as shown inFIG.31, a spiral path SP for pixel PSis depicted. In this example implementation, the pixel PSis to be moved around a predefined point P in accordance with the spiral path SP. Particularly, the pixel PSis to be moved from its starting position shown inFIG.31counterclockwise around the predefined point P along the spiral path SP. In this regard, the pixel PScan be moved in a spiral motion. In other implementations, the pixel PSmay be moved in a clockwise direction around the predefined point P. For this implementation, the predefined point P is depicted positioned within the perimeter71of the layer68inFIG.31. In other implementations, the predefined point P can be positioned along or outside of the perimeter71of the layer68.

At234D, the method200B includes flashing the pixel with radiant energy as the pixel is moved in the circular motion or the spiral motion around the predefined point to form at least part of the layer. For instance, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the circular motion or the spiral motion around the predefined point P.

In some implementations, at234D, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the spiral motion around the predefined point P. In some example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PScontinuously as the pixel PSis moved in the spiral motion around the predefined point P. In some example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the spiral motion around the predefined point P only when the pixel PSis moved to predetermined discrete positions.

In yet other example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the spiral motion around the predefined point P only when one or more target conditions are met. For instance, in one example implementation, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the spiral motion around the predefined point P only when a threshold area of the pixel PSis positioned within the perimeter71of the layer68. As one example, the threshold area of the pixel PScan be set at fifty percent (50%) of an area of the pixel PS. As yet another example, the threshold area of the pixel PScan be set at eighty percent (80%) of an area of the pixel PS. As a further example, the threshold area of the pixel PScan be set at ninety-five percent (95%) of an area of the pixel PS. Flashing a pixel only when a threshold area of the pixel is within a perimeter of the layer to be printed can produce more accurate printing results, especially at the perimeter of the layer. Further, flash intensity or flash time may be modulated as a function of pixel area to enhance printing, e.g., to blend a layer or edge.

In another example implementation, at234D, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the spiral motion around the predefined point P only when a threshold area of the pixel PSis positioned within the perimeter71of the layer68and when less than an overlap threshold area of the pixel PSoverlaps the flashed bulk area. As one example, the overlap threshold area of the pixel PScan be set at fifty percent (50%) of an area of the pixel PS. As yet another example, the overlap threshold area of the pixel PScan be set at eighty percent (80%) of an area of the pixel PS. As a further example, the threshold area of the pixel PScan be set at ninety-five percent (95%) of an area of the pixel PS. Flashing a pixel only when a threshold area of the pixel is within a perimeter of the layer to be printed and when less than an overlap threshold area of the pixel PSoverlaps the flashed bulk area can produce more accurate printing results and can prevent overlap flashing, which may prevent print through or uneven material properties.

By way of example, with specific reference toFIG.31, the flashed bulk area75created by flashing pixels P22, P23, P32, and P33at224B is shown. In this example implementation, the threshold area is set at eighty percent (80%) and the overlap threshold area is set at fifty percent (50%). When the pixel PSis moved from its initial position (shown in dashed lines inFIG.31; pixel PSis aligned with pixel P32in its initial position inFIG.31) in the spiral motion along the spiral path SP around the predefined point P and generally overlaps pixel P33, the pixel PSis not flashed as not less than the overlap threshold area of the pixel PSoverlaps the flashed bulk area75. Indeed, the entirety or nearly the entirety of pixel PSwould overlap the flashed bulk area75in such a position. The same is true when pixel PSgenerally overlaps pixel P23and then pixel P22as pixel PSis moved along the spiral path SP. When the pixel PSis moved to position P-1, the one or more target conditions required for flashing pixel PSare met because: 1) a threshold area of the pixel PSis positioned within the perimeter71of the layer68as eighty percent (80%) of the pixel PSis within the perimeter71; and 2) less than an overlap threshold area of the pixel PSoverlaps the flashed bulk area as less than fifty percent (50%) of the pixel PSoverlaps the flashed bulk area75. Accordingly, pixel PSis flashed at position P-1. The target conditions are likewise met when pixel PSis positioned at position P-2, and then at position P-3.

In some other implementations, at234D, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in a circular motion around the predefined point P. In some example implementations, for instance, the one or more processors112can cause the radiant energy device20to flash the pixel PScontinuously as the pixel PSis moved in the circular motion around the predefined point P. In some example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PSas the pixel PSis moved in the circular motion around the predefined point P only when the pixel PSis moved to predetermined discrete positions.

As noted above, at234C, the method200B can include moving a pixel of the plurality of pixels of the grid in a circular motion around a predefined point. By way of example, as shown inFIG.32, a circular path CP for pixel PCis depicted. In this example implementation, the pixel PCis to be moved around a predefined point P in accordance with the circular path CP. Particularly, the pixel PCis to be moved from its starting position shown inFIG.32clockwise around the predefined point P along the circular path CP. In this regard, the pixel PCcan be moved in a circular motion. In other implementations, the pixel PCmay be moved in a counterclockwise direction around the predefined point P. For this implementation, the predefined point P is depicted positioned within the perimeter71of the layer68inFIG.32. In other implementations, the predefined point P can be positioned along or outside of the perimeter71of the layer68. In some implementations, the build plan can be generated so that, at any given point, the one or more processors112can cause the radiant energy device20to perform as many simultaneous pixel flashes as possible, e.g., to perform the flashed bulk area with one or more pixels of the grid positioned at positions P-1, P-2, P-3. This may further optimize build time.

The pixel PCcan be flashed with radiant energy at234D of the method200B as the pixel PCis moved in the circular motion around the predefined point P to form at least part of the layer68. For instance, the one or more processors112can cause the radiant energy device20to flash the pixel PCas the pixel PCis moved in the circular motion around the predefined point P. In some implementations, at234D, the one or more processors112can cause the radiant energy device20to flash the pixel PCcontinuously as the pixel PCis moved in the circular motion around the predefined point P. In some example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PCas the pixel PCis moved in the circular motion around the predefined point P only when the pixel PCis moved to predetermined discrete positions.

In yet other example implementations, the one or more processors112can cause the radiant energy device20to flash the pixel PCas the pixel PCis moved in the circular motion around the predefined point P only when one or more target conditions are met. For instance, in one example implementation, the one or more processors112can cause the radiant energy device20to flash the pixel PCas the pixel PCis moved in the circular motion around the predefined point P only when a threshold area of the pixel PCis positioned within the perimeter71of the layer68. As one example, the threshold area of the pixel PCcan be set at fifty percent (50%) of an area of the pixel PS. As yet another example, the threshold area of the pixel PCcan be set at eighty percent (80%) of an area of the pixel PS. As a further example, the threshold area of the pixel PCcan be set at ninety-five percent (95%) of an area of the pixel PC. Flashing a pixel only when a threshold area of the pixel is within a perimeter of the layer to be printed can produce more accurate printing results, especially at or along the perimeter of the layer.

In another example implementation, at234D, the one or more processors112can cause the radiant energy device20to flash the pixel PCas the pixel PCis moved in the circular motion around the predefined point P only when a threshold area of the pixel PCis positioned within the perimeter71of the layer68and when less than an overlap threshold area of the pixel PCoverlaps the flashed bulk area75. As one example, the overlap threshold area of the pixel PCcan be set at fifty percent (50%) of an area of the pixel PC. As yet another example, the overlap threshold area of the pixel PCcan be set at eighty percent (80%) of an area of the pixel PC. As a further example, the threshold area of the pixel PCcan be set at ninety-five percent (95%) of an area of the pixel PC. Flashing a pixel only when a threshold area of the pixel is within a perimeter of the layer to be printed and when less than an overlap threshold area of the pixel PCoverlaps the flashed bulk area75can produce more accurate printing results and can prevent overlap flashing, which may prevent print through or uneven material properties.

By way of example, with specific reference toFIG.32, the flashed bulk area75created by flashing pixels P22, P23, P32, and P33at224B is shown. In this example implementation, the threshold area is set at eighty percent (80%) and the overlap threshold area is set at eighty percent (80%). When the pixel PCis moved from its initial position along the circular path CP around the predefined point P and reaches position PC-1, the one or more target conditions required for flashing pixel PCare met because: 1) a threshold area of the pixel PCis positioned within the perimeter71of the layer68as eighty percent (80%) of the pixel PCis within the perimeter71; and 2) less than an overlap threshold area of the pixel PSoverlaps the flashed bulk75area as less than eighty percent (80%) of the pixel PCoverlaps the flashed bulk area75. Accordingly, pixel PCis flashed at position PC-1. The target conditions are likewise met when pixel PCis positioned at position PC-2. In some embodiments, the build plan can be generated such that pixels P22, P23, P32, and P33are flashed simultaneously with pixel PCat one or more positions PC-1, PC-2, PC-3, PC-4 rather than serially. In other embodiments, two or more pixels of the grid78can be flashed simultaneously at positions PC-1, PC-2, PC-3, PC-4 to flash these areas simultaneously.

After the pixel PCcompletes one or more circular motions along the circular path CP and is flashed in accordance with the one or more target conditions, when the layer68is complete as determined at234E, at234F, the next layer may be formed in accordance with the method200B or printing may be completed if the present layer is the last layer to be formed. When the present layer is not completed as determined at234E, the one or more processors112cause the predefined point P to be moved to another predetermined location and234C and234D of the method200B are iterated. For instance, as shown inFIG.33, the predefined point P is moved to a location that is different than its location depicted inFIG.32. The predefined point P can be moved strategically based on the geometry of the layer68to be printed, for example.

As depicted inFIG.33, when the pixel PCis moved from its initial position along the circular path CP around the predefined point P and reaches position PC-3, the one or more target conditions required for flashing pixel PCare met because: 1) a threshold area of the pixel PCis positioned within the perimeter71of the layer68as eighty percent (80%) of the pixel PCis within the perimeter71; and 2) less than an overlap threshold area of the pixel PSoverlaps the flashed bulk area75as less than eighty percent (80%) of the pixel PCoverlaps the flashed bulk area75. Accordingly, pixel PCis flashed at position PC-3. The target conditions are likewise met when pixel PCis positioned at position PC-4. Thus, with the second iteration of234C and234D of the method200B, the flashed bulk area75and flashed areas corresponding to positions PC-1, PC-2, PC-3, and PC-4 begin to form the layer68to shape. It will be appreciated that this process may iterate for the present layer68so as to form the layer68to specification. It will further be appreciated that the predefined point associated with the spiral motion implementation may be moved and the process may iterate as set forth inFIG.29until the layer68is completed.

In accordance with another example implementation, a layer of a component can be printed by the apparatus10using a bulk flash and trace, spiral, and/or circle technique in conjunction with a tilt technique. Particularly, in execution of the trace and flash technique set forth in224C,224D of the method200A of FIG.18and/or in execution of the circulation motion or spiral motion and flash technique set forth in234C,234D of the method200B ofFIG.29, the pixel being moved and flashed can also be tilted with respect to a horizontal plane that is orthogonal to the Z-axis direction. The tilted pixel technique can provide enhanced edge construction of a layer68of a component, especially for components having one or more curved surfaces.

With reference now toFIG.33Ain addition toFIGS.1A and1B,2, and18through33,FIG.33Aprovides a schematic view of a pixel being tilted while also being traced, circled, or spiraled to flash a layer68. As depicted, a pixel PTILTof a grid is shown tilted with respect to a horizontal plane HP. The pixel PTILTcan be tilted by adjusting the optics70(e.g., by adjusting a lens) and/or by moving the image forming apparatus64(e.g., with an actuator), for example. In some embodiments, the pixel PTILTis tilted so that the pixel PTILTis tangentially aligned with an edge of a layer68or the flashed bulk area75, e.g., as shown inFIG.33A. In other embodiments, the pixel PTILTis tilted by a tilt angle θ. In such embodiments, the tilt angle θ can be greater than 0° and equal to or less than 90°. In other embodiments, the tilt angle θ can be greater than 200 and equal to or less than 70°.

In some implementations, the pixel PTILTcan be tilted as the pixel PTILTis traced around the perimeter71, e.g., at224C. The pixel PTILTcan be flashed at224D continuously along the perimeter71, periodically at predetermined discrete positions along the perimeter71, periodically according to a time interval, etc. In other implementations, the pixel PTILTcan be tilted as the pixel PTILTis moved in a circular motion or spiral motion around a predefined point, e.g., at234C. The pixel PTILTcan be flashed at234D continuously, periodically, and/or according to any of the criteria previously noted.

In accordance with another example implementation of the present disclosure, a method can include moving a pixel “like a pen” to completely form a layer or form the layer after a flashed bulk layer is formed. In some implementations, the method can include flashing one or more pixels of a plurality of pixels of a grid with radiant energy to form a flashed bulk area of the layer; moving at least one pixel of the plurality of pixels around the flashed bulk area; and flashing the at least one pixel with radiant energy as the at least one pixel is moved around the flashed bulk area to form at least part of the layer.

In some further implementations, moving the at least one pixel of the plurality of pixels around the flashed bulk area includes moving the at least one pixel in a tracing motion around a perimeter of the layer. In yet other implementations, moving the at least one pixel of the plurality of pixels around the flashed bulk area includes moving the at least one pixel in a spiral motion around a predefined point. In some other implementations, moving the at least one pixel of the plurality of pixels around the flashed bulk area includes moving the at least one pixel in a circular motion around a predefined point.

In other implementations, moving the at least one pixel of the plurality of pixels around the flashed bulk area includes moving the at least one pixel in a zig-zag motion along a perimeter of the layer. That is, the at least one pixel can be traced along the perimeter with a zig-zag motion. The zig-zag motion can include moving the at least one pixel back and forth along the perimeter so that at least a portion of the at least one pixel is always aligned with the perimeter. The zig-zag motion can include moving the at least one pixel back and forth inward toward a center of the layer and outward away from the center as the at least one pixel is moved along the perimeter. The zig-zag motion can include moving the at least one pixel back and forth along a substantially same direction as the portion of the perimeter along which the at least one pixel is being moved.

In some other embodiments, moving the at least one pixel of the plurality of pixels around the flashed bulk area includes moving the at least one pixel in at least two of: a tracing motion around a perimeter of the layer, a spiral motion around a predefined point, a circular motion around a predefined point, and a zig-zag motion along a perimeter of the layer.

In some implementations, a method includes moving at least one pixel of a plurality of pixels and flashing the at least one pixel with radiant energy as the at least one pixel is moved to form at least part of the layer. In such implementations, the at least one pixel can be moved about one or more flashed pixels or none. In this regard, the at least one pixel can be moved and flashed to start formation of a layer or can be used to add on to a layer in progress.

In some other implementations, as the at least one pixel is moved, e.g., traced, spiraled, circled, zig-zagged, etc., the at least one pixel can be blurred or defocused by adjusting the focal point of the optic device of the radiant energy device. For instance, for a traced or zig-zagged pixel, the pixel may be blurred along a portion or the entire perimeter of the layer. For a spiraled or circled pixel, the pixel may be blurred as the pixel approaches the perimeter, e.g., to soften or round the edge of the layer.

In yet another implementation, a radiant energy device includes a first set of components, such as those depicted inFIG.1A, to form a flashed bulk area, and a second set of components, similar to the first set of components, that is dedicated to moving the pixel in a trace, spiral, circular, and/or tilting motion.

FIG.34provides a method300of controlling an additive manufacturing apparatus, such as a tiled DLP machine, for producing components. Although not depicted inFIG.34, the method300can include receiving data, such as the data150depicted inFIG.2. The data can include layer data, grid data, optimization rules, and/or feedback data, for example. Further, the method300can include generating a layer build plan based at least in part on the received data. The generated layer build plan can indicate instructions for printing the layer to be printed in one or more of the tile shifting techniques provided below. To build up or print a layer, one or more processors of a computing system, such as the one or more processors112of the computing system110ofFIG.2, can receive the data, generate the layer build plan, and then can execute the layer build plan, causing the additive manufacturing apparatus10(FIG.1A) to build up or print the layer. The layer build plan can be executing in accordance with method300as provided below.

At302, the method300includes determining whether a perimeter of a layer to be printed fits within a single tile of the grid. When the perimeter of the layer to be printed fits within a single tile of the grid, the method300proceeds to304. In contrast, when the layer to be printed does not fit within a single tile of the grid, more than one tile is needed to print the layer, and consequently, the method300proceeds to314.

By way of example, determining whether a layer to be printed fits within a single tile of a grid projected by the tiled DLP machine. When the layer to be printed fits within the tile of the grid, the method300proceeds to304with reference toFIG.35, a grid78having four tiles is depicted, including a first tile T1, a second tile T2, a third tile T3, and a fourth tile T4. Each tile T1, T2, T3, T4 has an 8×8 pixel configuration. That is, each tile T1, T2, T3, T4 has eight rows and eight columns of pixels. The layer68to be printed is depicted as well. With reference now also toFIG.36, for this example, it is determined that the layer68to be printed fits within a single tile of the grid78. For instance, if the second tile T2 (or any of the other tiles) is centered with the layer68to be printed, a perimeter71of the layer68to be printed fits entirely within the second tile T2. Accordingly, as noted, the method300proceeds to304.

At304, the method300includes moving the grid so that a first border of the tile aligns with a first boundary of the layer to be printed. For instance, as depicted inFIG.37and continuing with the example above, the grid is moved so that a first border B1 of the second tile T2 aligns with a first boundary BD1 of the layer68to be printed. Particularly, in this example, the top or first border B1 of the second tile T2 is aligned with the top or first boundary BD1 of the layer68to be printed, e.g., along the Y-axis direction. In some implementations, in addition to aligning the first border B1 with the first boundary BD1 of the layer68, at least one side border of the second tile T2 can be aligned with a side boundary of the layer68, e.g., along the X-axis direction. In this example, the side borders of the second tile T2 are aligned with respective side boundaries of the layer68.

At306, the method300includes flashing, with the grid positioned so that the first border of the tile aligns with the first boundary of the layer to be printed, pixels of the tile that are positioned substantially within a perimeter of the layer to be printed. A given pixel of the tile is substantially within a perimeter of the layer to be printed when at least a predetermined percentage of an area of the given pixel (or predetermined area percentage) is within the boundaries of the layer68to be printed. In some implementations, the predetermined area percentage is seventy-five percent (75%). In other implementations, the predetermined area percentage is eighty-five percent (85%). In yet other implementations, the predetermined area percentage is ninety-five percent (95%). For instance, as shown inFIG.38and continuing with the example above, all pixels except for pixels P11, P18, P71, P78, and the pixels of Row 8 of the second tile T2 are determined to be substantially within a boundary of the layer68to be printed. Accordingly, such pixels are flashed while the pixels P11, P18, P71, P78, and the pixels of Row 8 of the second tile T2 are not.

At308, the method300includes moving the grid so that a second border of the tile aligns with a second boundary of the layer to be printed. For instance, as depicted inFIG.39and continuing with the example above, the grid78is moved so that a second border B2 of the second tile T2 (which in this example is a border delineating the Row 7 pixels with the Row 8 pixels) aligns with a second boundary BD2 of the layer68to be printed. Particularly, in this example, the bottom or second border B2 of the second tile T2 is aligned with the bottom or second boundary BD2 of the layer68to be printed.

At310, the method300includes flashing, with the grid positioned so that the second border of the tile aligns with the second boundary of the layer to be printed, pixels of the tile that are i) positioned substantially within the boundary of the layer to be printed; and ii) aligned at least in part with unflashed areas of the layer. In some implementations, only pixels of the tile that are i) positioned substantially within the boundary of the layer to be printed; and ii) aligned at least in part with unflashed areas of the layer, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. The predetermined percentage can be any suitable percentage, such as ten percent (10%), twenty percent (20%), or thirty percent (30%).

For instance, as depicted inFIG.40, pixels P61, P68of Row 6 and pixels P72through P77of Row 7 of the second tile T2 are determined to be substantially within a boundary of the layer68to be printed, e.g., by a predetermined area percentage, and are aligned at least in part with areas of the layer that have not previously been flashed, or unflashed areas, wherein the unflashed areas aligned with such pixels each have an area that is equal to or greater than a predetermined percentage of an area of their respective pixels. As shown, pixel P61is positioned substantially within the boundary or perimeter71of the layer68to be printed and is aligned in part with an unflashed area UF-1. Indeed, the bottom half of pixel P61aligns with the unflashed area UF-1. The same is true for pixel P68. Pixel P68is positioned substantially within the boundary or perimeter71of the layer68to be printed and is aligned in part with an unflashed area UF-2. Further, as shown inFIG.40, pixels P72through P77of Row 7 are each positioned substantially within the boundary or perimeter71of the layer68to be printed and are each aligned in part with unflashed areas.

Accordingly, at310, these noted pixels are flashed. The pixels of the second tile T2 that are either not positioned substantially within the boundary of the layer68to be printed or are not aligned at least in part with unflashed areas of the layer68are not flashed. For instance, the pixels of Row 8 are not positioned substantially within the boundary of the layer68to be printed, and thus, such pixels are not flashed. In addition, while other pixels are positioned substantially within the boundary of the layer68to be printed, such as pixel P12, such pixels are not aligned at least in part with an unflashed area of the layer68. As shown, for example, pixel P12is entirely aligned with an area of the layer68that has already been flashed. Accordingly, at310, pixel P12and similarly situated pixels are not flashed.

At312, the method300includes determining whether the layer to be printed is complete. When it is determined that the layer to be printed is completed, the method can proceed to326where printing can cease or the next layer can be built up, e.g., using method300. When it is determined that the layer to be printed is not completed, the method300can iterate308,310,312until the layer is complete. When this occurs, the grid is moved so that a subsequent border of the tile (i.e., a border that has not been previously aligned with a boundary of the layer to be printed) aligns with a subsequent boundary of the layer to be printed (i.e., a boundary that has not been previously aligned with a border of the tile). By aligning and flashing pixels with a boundary (e.g., a perimeter) of a layer and subsequently shifting the tile to align with one or more subsequent boundaries and intelligently flashing one or more pixels at each of the tile positions, the layer can be efficiently and intelligently printed. In this regard, optimal buildup of the desired geometry of the layer can be achieved. For instance,FIG.40depicts the layer built up to a satisfactory approximation of the desired shape depicted inFIG.41.

Referring now specifically toFIG.34, as noted previously, at302, when it is determined that the layer to be printed does not fit within a single tile of the grid, more than one tile is needed to print the layer, and consequently, the method300proceeds to314.

At314, the method300includes determining a number of tiles required to cover an area of the layer to be printed. By way of example, with reference toFIG.43, a grid78having four tiles is depicted, including a first tile T1, a second tile T2, a third tile T3, and a fourth tile T4. Each tile T1, T2, T3, T4 is configured in an 8×8 pixel configuration. The layer68to be printed is depicted as well. As shown, the layer68to be printed has an L-shape in this example. With reference now also toFIG.44, for this example, it is determined that the layer68to be printed (as represented by its outline71) does not fit within a single tile of the grid78and that three (3) tiles, denoted by T1-1, T3-3, and T4-4, are needed to cover the area of the layer68to be printed.

At316, the method300includes moving the grid so that a first border of a tile aligns with a first boundary of the layer to be printed. For instance, as depicted inFIG.45and continuing with the example above, the grid78is moved so that a first border B1 of the first tile T1 aligns with a first boundary BD1 of the layer68to be printed. Particularly, in this example, the top or first border B1 of the first tile T1 is aligned with the top or first boundary BD1 of the layer68to be printed.

At318, the method300includes flashing pixels of the tile that are i) positioned substantially within a boundary of the layer to be printed and ii) aligned at least in part with areas of the layer that have not previously been flashed. As noted above, a given pixel of the tile is substantially within a boundary of the layer to be printed when at least a predetermined percentage of an area of the given pixel (or predetermined area percentage) is within the boundaries or perimeter71of the layer68to be printed. In some implementations, the predetermined percentage of area is seventy-five percent (75%). In other implementations, the predetermined percentage of area is eighty-five percent (85%). In yet other implementations, the predetermined percentage of area is ninety-five percent (95%).

As shown inFIG.45and continuing with the example above, pixels P11-P15of Row 1, P21-P25of Row 2, P31-P35of Row 3, P41-P45of Row 4, P51-P55of Row 5, P61-P65of Row 6, P71-P78of Row 7, and P51-P88of Row 8 of the first tile T1 (the other tiles are not shown inFIG.45) are determined to be substantially within a boundary of the layer68to be printed. Further, as no area of the layer has yet been flashed, these pixels are aligned at least in part with areas of the layer that have not previously been flashed. Accordingly, as depicted inFIG.45, such pixels are flashed while the other pixels are not.

At320, the method includes determining whether further tile movement and flashing is needed using the current tile. When further tile movement and flashing is needed using the current tile, the method300proceeds to316and316,318, and320are iterated. In contrast, when further tile movement and flashing is not needed using the current tile, the method300proceeds to322.

Continuing with the example noted above and with reference toFIGS.45and46, after flashing pixels P11-P15of Row 1, P21-P25of Row 2, P31-P35of Row 3, P41-P45of Row 4, P51-P55of Row 5, P61-P65of Row 6, P71-P78of Row 7, and P51-P88of Row 8 of the first tile T1, there is still an area80of the layer68to be printed that has not been flashed but is within an area of the first tile T1. Accordingly, in this example, it is determined that further tile movement and flashing is needed using the current tile, the first tile T1, and the method300iterates316and316,318, and320.

Accordingly, at the iteration of316, the grid78is moved so that a subsequent border of the first tile T1 aligns with a subsequent boundary of the layer68to be printed. For instance, as depicted inFIG.46, the grid78is moved so that a second border B2 of the first tile T1 aligns with a second boundary BD2 of the layer68to be printed. As a result, in this example, the first tile T1 is moved to the right by ¼ pixel along the X-axis direction. This effectively aligns pixels P15-P65of Column 5 with the area80of the layer68that has not been flashed but is within an area of the first tile T1.

At the iteration of318, pixels of the first tile T1 that are i) positioned substantially within the boundary of the layer68to be printed; and ii) aligned at least in part with areas of the layer that have not previously been flashed (i.e., unflashed areas) are flashed. For instance, as depicted, pixels P15-P65of Column 5 and pixels P78-P88of Column 8 of the first tile T1 are determined to be substantially within a boundary of the layer68to be printed, e.g., by a predetermined area percentage, and are aligned at least in part with areas of the layer that have not previously been flashed. Accordingly, as shown inFIG.46, pixels P15-P65of Column 5 and pixels P78-P88of Column 8 of the first tile T1 are flashed to build up these unflashed areas of the layer68.

At the iteration of320, it is again determined whether further tile movement and flashing is needed using the current tile. In this example, further tile movement and flashing is not needed using the current tile as there is no area of the layer68to be printed that i) has not been flashed but is within the area of the first tile T1. Accordingly, as depicted inFIG.34, the method300proceeds to322.

At322, the method300includes iterating316,318,320using a subsequent tile. For instance, as shown inFIG.47, the third tile T3 is moved at316so that a border of the third tile T3 aligns with a boundary of the layer68to be printed. Particularly, in this example, a bottom border B3 of the third tile T3 is aligned with the bottom boundary BD3 of the layer68to be printed. Then, at318, the pixels of the second tile T1 that are i) positioned substantially within a boundary of the layer to be printed and ii) aligned at least in part with areas of the layer that have not previously been flashed are flashed. For instance, as shown inFIG.47, all pixels of Rows4through8of the third tile T3 are determined to be substantially within a boundary of the layer68to be printed. Further, as these pixels are aligned at least in part with areas of the layer that have not previously been flashed (see the area below the first tile T1 inFIG.46), such pixels are flashed while the other pixels of the third tile T3 are not. That is, all pixels of Rows1through4are not flashed while all pixels of Rows4through8of the third tile T3 are flashed. The pixels of Row 4 overlap in part with areas of the layer68that have already been formed, e.g., by the first tile T1 as noted above; thus, when the pixels of Row 4 are flashed, some previously flashed areas are flashed once again. Next, at320, it is determined whether further tile movement and flashing is needed using the current tile. In this example, further tile movement and flashing is not needed using the current tile, as there is no area of the layer68to be printed that i) has not been flashed but is within the area of the third tile T3. Accordingly, as depicted inFIG.34, the method300proceeds to324.

At324, the method300includes determining whether the layer to be printed is completed. For this example, as depicted inFIG.47, an area of the layer68has not yet been flashed or formed. Indeed, the area to the right of the third tile T3 has not yet been flashed. Accordingly, the method300returns to322as depicted inFIG.34.

At this iteration of322, the method300includes iterating316,318,320using a subsequent tile, or this example the fourth tile T4. For instance, as shown inFIG.48, the fourth tile T4 is moved at316so that a border of the fourth tile T4 aligns with a boundary of the layer68to be printed. Particularly, in this example, the top border B4 of the fourth tile T4 is aligned with the top boundary BD4 of the layer68to be printed. Then, at318, the pixels of the tile that are i) positioned substantially within a boundary of the layer to be printed and ii) aligned at least in part with areas of the layer that have not previously been flashed are flashed. For instance, as shown inFIG.48, pixels P14-P18of Row 1, pixels P24-P28of Row 2, pixels P34-P38of Row 3, pixels P44-P48of Row 4, pixels P54-P58of Row 5, and pixels P64-P68of Row 6 all meet this criteria. While the pixels of Row 7 each align at least in part with an area or areas of the layer68that has/have not previously been flashed, such pixels are not positioned substantially within a boundary or perimeter71of the layer68to be printed. Accordingly, they are not flashed. It is determined at320that a further tile movement/flashing is needed as there is still an area81of the layer68to be printed that has not been flashed but is within an area of the fourth tile T4. Accordingly, in this example, it is determined that further tile movement and flashing is needed using the current tile, the fourth tile T4, and the method300iterates316and316,318, and320.

Accordingly, the fourth tile T4 is moved at316by 1 and ½ pixels upward along the Y-axis direction. In this regard, a bottom border B5 of the fourth tile T4 is aligned with the bottom boundary BD5 of the layer68to be printed as shown inFIG.49. In alternative embodiments, the fourth tile T4 can be moved at316by ½ a pixel upward along the Y-axis direction. Then, at318, the pixels of the tile that are i) positioned substantially within a boundary of the layer to be printed and ii) aligned at least in part with areas of the layer that have not previously been flashed are flashed. For instance, as shown inFIG.49, pixels P84-P88of Row 8 are flashed. Thus, the previously unflashed area81is built up. It is then determined at320that no further tile movement/flashing is needed as there is no area of the layer68to be printed that has not been flashed within an area of the fourth tile T4. Accordingly, in this example, the method300proceeds to324. At324, it is determined that the layer68is in fact completed.FIG.50depicts the completed layer68. Thus, the method300proceeds to326. At326, the method300can be iterated for subsequent layers, or if the component is complete, printing may cease.

In another example aspect of the present disclosure, it may be desirable to print a layer or component that has circular or fidelity-critical features. Two exemplary approaches are provided below.

FIG.51provides a first approach of implementing method400to build up components that have circular or fidelity-critical features using an additive manufacturing apparatus, such as a tiled DLP machine. Although not depicted inFIG.51, the method400can include receiving data, such as the data150depicted inFIG.2. The data can include layer data, grid data, optimization rules, and/or feedback data, for example. The one or more optimization rules can dictate or instruct how the layer build plan is constructed, or rather, how the grid is to be shifted around and flashed to build the layer. Particularly, the one or more optimization rules can set forth and define the rules set forth in the method400ofFIG.51, such as how the grid is to be moved and flashed at402and404to flash a greatest number of pixels of a tile of the grid are positioned within a predetermined area percentage of a perimeter of a layer to be printed, and then, how the grid is to be moved and flashed at406and408to flash one or more pixels along the perimeter of the layer to be printed to ultimately enhance the printing of the circular or fidelity-critical features. Further, the one or more optimization rules can set forth and define the parameters of the method400, such as the predetermined area percentage, the predetermined percentage of an area of at least one pixel, the flash intensity, etc. The method400can include generating a layer build plan based at least in part on the received data. The generated layer build plan can indicate instructions for printing the layer to be printed in one or more of the tile shifting techniques used to print components that have circular or fidelity-critical features as provided below. To build up or print a layer, the one or more processors112of the computing system110can receive the data, generate the layer build plan, and then can execute the layer build plan, causing the additive manufacturing apparatus10to build up or print the layer. The layer build plan can be executing in accordance with method400as provided below.

At402, the method400includes moving a grid so that a greatest number of pixels of a tile of the grid are positioned within a predetermined area percentage of a perimeter of a layer to be printed. By way of example, with reference toFIG.52, a grid78having four tiles is depicted, including a first tile T1, a second tile T2, a third tile T3, and a fourth tile T4. Each tile T1, T2, T3, T4 is configured in an 8×8 pixel configuration. The layer68to be printed is depicted as well. The layer68has circular features in this example. As depicted inFIG.53, one of the tiles can be moved so that a greatest number of pixels of one of the tiles of the grid78are positioned within a predetermined area percentage of a perimeter71of the layer68to be printed.

At404, the method400includes flashing the pixels of the grid that are positioned within the predetermined area percentage of the perimeter of the layer to be printed. For instance, as shown inFIG.53, pixels P13-P16of Row 1, P22-P27of Row 2, P32-P37of Row 3, P41-P48of Row 4, P51-P58of Row 5, P62-P67of Row 6, P72-P77of Row 7, and P83-P86of Row 8 are flashed as they are positioned within a predetermined area percentage of the perimeter71of the layer68to be printed. The other pixels of the first tile T1 are not flashed as they are not within the predetermined area percentage of the perimeter71of the layer68to be printed.

At406, the method400includes moving the grid so that at least one pixel of the tile is positioned i) substantially within a perimeter of the layer to be printed; and ii) aligned with an unflashed area of the layer to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. In some implementations, this can involve moving the grid in a first direction and in a second direction that is perpendicular to the first direction. That is, the grid can be moved diagonally to accomplish this task. In some implementations, the grid is moved diagonally less than a length or width of a pixel, such as by a quarter of a length of a pixel. In some implementations, the grid is moved in the first direction and in the second direction so that at least one pixel of the pixels of the tile is positioned i) substantially within a perimeter of the layer to be printed; and ii) aligned with an unflashed area of the layer to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. In other implementations, the grid need not be moved in a diagonal direction, rather, the grid can be moved solely along the X-axis direction or solely along the Y-axis direction to accomplish this task.

In some example implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is ninety-five percent (95%) within the perimeter of the layer. In other implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is ninety percent (90%) within the perimeter of the layer. In yet other implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is entirely within the perimeter of the layer.

Continuing with the example above and with reference toFIG.54, the grid78is moved so that at least one pixel of the first tile T1 is positioned i) substantially within the perimeter71of the layer68to be printed; and ii) aligned with an unflashed area of the layer68to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. Particularly, the grid is moved so that pixel P22is positioned substantially within the perimeter71of the layer68to be printed and is aligned with an unflashed area83of the layer68to be printed, wherein the unflashed area83has an area that is equal to or greater than a predetermined percentage (e.g., ten percent (10%)) of an area of pixel P22. Moreover, pixel P47is positioned substantially within the perimeter71of the layer68to be printed and is aligned with an unflashed area84of the layer68to be printed, wherein the unflashed area84has an area that is equal to or greater than a predetermined percentage (e.g., ten percent (10%)) of an area of pixel P47. No other pixels of the first tile T1 meet this criteria.

At408, the method includes flashing the at least one pixel that is/are positioned i) substantially within a perimeter of the layer to be printed; and ii) aligned with an unflashed area of the layer to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. As shown inFIG.54, pixel P22is flashed to build up or print the unflashed area83and pixel P47is flashed to build up or print the unflashed area84.

At410, the method400includes determining whether there are other unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. When there are other unflashed areas meeting this criteria, the method400iterates406,408, and410, e.g., until there are no longer any unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. The predetermined percentage of an area of the at least one pixel can be, for example, 5%, 10%, 25%, etc. depending on the desired fidelity of the perimeter71of the layer68. An unflashed area is considered to be “proximate” the perimeter71if it touches the perimeter71or segment thereof. For instance, as depicted inFIG.55, the method400can iterate and certain pixels can be flashed so that all unflashed areas unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area equal to or greater than a predetermined percentage of an area of a given pixel of the tile can be printed or built up.

When, as determined at410, there are no other unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile, then the method proceeds to412to end printing of the layer68.FIG.56depicts the finished layer68built up with a high fidelity circular perimeter. Method400can then iterate for subsequent layers until the component is completed.

FIG.57provides a second approach of implementing method400to build up components that have circular or fidelity-critical features using an additive manufacturing apparatus, such as a tiled DLP machine. Although not depicted inFIG.57, the method400can include receiving data, such as the data150depicted inFIG.2. The data can include layer data, grid data, optimization rules, and/or feedback data, for example. The one or more optimization rules can dictate or instruct how the layer build plan is constructed, or rather, how the grid is to be shifted and/or rotated around and flashed to build the layer. Particularly, the one or more optimization rules can set forth and define the rules set forth in the method400ofFIG.57, such as how the grid is to be moved and flashed at402and404to flash a greatest number of pixels of a tile of the grid are positioned within a predetermined area percentage of a perimeter of a layer to be printed, and then, how the grid is to be rotated and flashed at406and408to flash one or more pixels along the perimeter of the layer to be printed to ultimately enhance the printing of the circular or fidelity-critical features. Further, the one or more optimization rules can set forth and define the parameters of the method400ofFIG.57, such as the predetermined area percentage, the predetermined percentage of an area of at least one pixel, the flash intensity, etc. The method400can include generating a layer build plan based at least in part on the received data. The generated layer build plan can indicate instructions for printing the layer to be printed in one or more of the tile shifting techniques used to print components that have circular or fidelity-critical features as provided below. To build up or print a layer, the one or more processors112of the computing system110can receive the data, generate the layer build plan, and then can execute the layer build plan, causing the additive manufacturing apparatus10to build up or print the layer. The layer build plan can be executing in accordance with method400ofFIG.57as provided below.

Actions402and404of the second approach to method400ofFIG.57are implemented in the same manner as provided inFIG.51and described above. Thus, for the sake of brevity, the details of402and404will not be repeated here.

At416, the method400includes rotating the grid so that at least one pixel of the tile is positioned i) substantially within a perimeter of the layer to be printed; and ii) aligned with an unflashed area of the layer to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. In some implementations, for example, the grid can be rotated by forty-five degrees (45°). However, the grid can be rotated by any suitable degree, such as between one degree (10) and eighty-nine degrees (89°). The grid can be rotated clockwise or counterclockwise. In yet other implementations, the grid can be rotated negative one hundred eighty degrees (−180°) to positive one hundred eighty degrees (+180°).

In some example implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is ninety-five percent (95%) within the perimeter of the layer. In other implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is ninety percent (90%) within the perimeter of the layer. In yet other implementations, the at least one pixel of the tile is positioned substantially within the perimeter of the layer to be printed when the at least one pixel is entirely within the perimeter of the layer.

By way of example, with reference toFIG.58, the grid78is rotated forty-five degrees (45°) counterclockwise (or forty-five degrees (45°) clockwise) so that pixels PR1-1, PR1-2, PR1-3, PR1-4, PR1-5, PR1-6are each positioned i) substantially within the perimeter71of the layer68to be printed; and ii) are each aligned with an unflashed area of the layer68to be printed, wherein each unflashed area has an area that is equal to or greater than a predetermined percentage (e.g., fifteen percent (15%)) of an area of a given pixel of the tile. Particularly, pixels PR1-1, PR1-2, PR1-3, PR1-4, PR1-5, PR1-6are each positioned substantially within the perimeter71of the layer68and are aligned respectively with unflashed areas85-1,85-2,85-3,85-4,85-6that each have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile.

At418, the method includes flashing the at least one pixel that is/are positioned i) substantially within a perimeter of the layer to be printed; and ii) aligned with an unflashed area of the layer to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of the at least one pixel. As shown inFIG.58, pixels PR1-1, PR1-2, PR1-3, PR1-4, PR1-5, PR1-6are flashed. When such pixels are flashed, unflashed areas85-1,85-2,85-3,85-4,85-6are built up or printed.

At420, the method400includes determining whether there are other unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. When there are other unflashed areas meeting this criteria, the method400iterates416,418, and420, e.g., until there are no longer any unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. The predetermined percentage of an area of the at least one pixel can be, for example, 5%, 10%, 25%, etc. depending on the desired fidelity of the perimeter71of the layer68.

For instance, as depicted inFIG.58, the method400can iterate in such a way that the grid is rotated ninety degrees (90°) counterclockwise (or ninety degrees (90°) clockwise) so that pixels PR2-1, PR2-2, PR2-3, PR2-4, PR2-5, PR2-6are each positioned i) substantially within the perimeter71of the layer68to be printed; and ii) are each aligned with an unflashed area of the layer68to be printed, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. Particularly, pixels PR2-1, PR2-2, PR2-3, PR2-4, PR2-5, PR2-6are each positioned substantially within the perimeter71of the layer68and are aligned respectively with unflashed areas86-1,86-2,86-3,86-4,86-5,86-6that each have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. Once the pixels PR2-1, PR2-2, PR2-3, PR2-4, PR2-5, PR2-6are positioned in place, at the iteration of418, pixels PR2-1, PR2-2, PR2-3, PR2-4, PR2-5, PR2-6are flashed. When such pixels are flashed, unflashed areas86-1,86-2,86-3,86-4,86-5,86-6are built up or printed. At the iteration of420, it is again determined whether there are other unflashed areas proximate the perimeter71(or a segment of the perimeter71) that have an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile. In this example, there are no further unflashed areas that meet this criteria, and accordingly, the method400ofFIG.57proceeds to422to end printing of the layer68.FIG.59depicts the finished layer68built up with a high fidelity circular perimeter in accordance with the second approach of method400. The method400ofFIG.57can then iterate for subsequent layers until the component is completed.

In accordance with example aspects of the present disclosure, the layers of a component can be built up using one, some, or any suitable combination of the printing techniques described herein, e.g., any suitable combination of the techniques provided herein, such as the techniques outlined inFIG.5,FIG.18,FIG.29,FIG.33A,FIG.34,FIG.51, and/orFIG.57. In some implementations, for example, a pixel shifting technique can be used in conjunction with a tile shifting technique to form a single layer, multiple layers, or generally, a component. For instance, the teachings ofFIG.29and the accompanying text can be used in conjunction with the teachings ofFIG.34andFIG.51and the accompanying text.

Further, in accordance with other inventive aspects of the present disclosure, the layers of a component can be built up using one, some, or any suitable combination of the printing techniques described herein using multiple projectors, such as projector60and the second projector74depicted inFIG.1A. As one example, using the projector60, a grid can be shifted in place and pixels of the grid can be flashed to form a bulk flashed area. Then, using the second projector74, one or more pixels can be traced around the flashed bulk area and flashed to form a high resolution perimeter around the flashed bulk area.

FIG.60provides a flow diagram for a method600of additively manufacturing an object. At602, the method600can include contacting a surface of an object with a photopolymerizable material. At604, the method600can include irradiating or flashing at least a portion of a cross section of the object using a first projector, such as projector60. At606, the method600can include irradiating or flashing at least a portion of the cross section of the object using a second projector, such as second projector74. At608, the method600can include separating the object from the photopolymerizable material. At610, the method600can include iterating the method as necessary to build up the object. In such implementations, the projector60can flash at least a portion of the cross section of the object with a first resolution while the second projector74can flash at least a portion of the cross section of the object with a second resolution, the first resolution being a more coarse resolution relative to the second resolution.

In some further implementations, the projector60can be fixed and the second projector74can be movable. In yet other implementations, the grid projected by the second projector74is smaller than the grid projected by the projector60. In some further implementations, the grid projected by the second projector74is moved at least once during build up or printing of the object. In yet other implementations, the radiant energy device20can include multiple projectors, including at least one coarse projector and at least two fine projectors. In such implementations, one, some, all or none of the fine resolution projectors can be movable. For instance, if there is one or a small number of fine resolution projectors, they can each be movable. In other implementations, particularly where there are enough fine projectors to project their respective grids across the entire print area, they can each be fixed.

In accordance with yet other inventive aspects of the present disclosure, the layers of a component can be built up using one, some, or any suitable combination of the printing techniques described herein using a projector equipped with variable resolution. As one example, using the projector60, a grid can be shifted in place and pixels of the grid can be flashed with a coarse resolution to form a bulk flashed area. Then, the resolution of the projector60can be switched from the coarse resolution to a fine resolution. The coarse resolution is coarse relative to the fine resolution. The one or more pixels can be traced around the flashed bulk area and flashed to form a high resolution perimeter around the flashed bulk area.

FIG.61provides a flow diagram for a method700of additively manufacturing an object. At702, the method700can include contacting a surface of an object with a photopolymerizable material. At704, the method700can include irradiating or flashing at least a first portion of the object with a first resolution using a projector at a first position. At706, the method700can include irradiating or flashing at least a second portion of the object with a second resolution using the projector at a second position, the first resolution being a different resolution than the second resolution. As one example, the first resolution can be more coarse than the second resolution. As another example, the first resolution can be finer than the second resolution. At708, the method700can include separating the object from the photopolymerizable material. At710, the method600can include iterating the method as necessary to build up the object. In some implementations, the projector having variable resolution is operable to raster or move about the printable field. In some implementations, the first portion and the second portion of the object are within the same layer. In other implementations, the first portion and the second portion of the object are within different layers of the object. In some implementations, the method includes changing a resolution of the projector, e.g., from the first resolution to the second resolution. In such implementations, changing the resolution of the projector can include changing a size of the pixels of the grid.

FIG.62depicts certain components of the computing system110according to example embodiments of the present disclosure. As noted, the computing system110can include one or more processor(s)112and one or more memory device(s)114. The one or more processor(s)112and one or more memory device(s)114can be implemented in one or more computing device(s)111. The one or more processor(s)112can include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, an application specific integrated circuit (ASIC, a digital signal processor (DSP), a field-programmable gate array (FPGA), logic device, one or more central processing units (CPUs), graphics processing units (GPUs) (e.g., dedicated to efficiently rendering images), processing units performing other specialized calculations, etc. The memory device(s)114can include one or more non-transitory computer-readable storage medium(s), such as RAM, ROM, EEPROM, EPROM, flash memory devices, magnetic disks, etc., and/or combinations thereof.

The memory device(s)114can include one or more computer-readable media and can store information accessible by the one or more processor(s)112, including instructions115that can be executed by the one or more processor(s)112. The instructions115may include one or more steps or actions of the method200,200A,200B described above. For instance, the memory device(s)114can store instructions115for running one or more software applications, displaying a user interface, receiving user input, processing user input, etc. In some implementations, the instructions115can be executed by the one or more processor(s)112to cause the one or more processor(s)112to perform operations, e.g., such as one or more portions of methods described herein. The instructions115can be software written in any suitable programming language or can be implemented in hardware. Additionally, and/or alternatively, the instructions115can be executed in logically and/or virtually separate threads on processor(s)112.

The one or more memory device(s)114can also store data116that can be retrieved, manipulated, created, or stored by the one or more processor(s)112. The data116can include, for instance, data150to facilitate performance of the method200described herein. The data116can be stored in one or more database(s). The one or more database(s) can be connected to computing system110by a high bandwidth LAN or WAN, or can also be connected to the computing system110through network(s) (not shown). The one or more database(s) can be split up so that they are located in multiple locales. In some implementations, the data116can be received from another device.

The computing device(s)111can also include a communication module or interface118used to communicate with one or more other component(s) of computing system110or the additive manufacturing apparatus10over the network(s). The communication interface118can include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.

As provided herein, the computing system110may be operably coupled with one or more of the one or more controllable devices120, actuator assembly52, the drive system28, the image forming apparatus64, and/or the radiant energy device20, among others. The drive system28may control the foil movement while the actuator assembly52controls the movement of the stage18. As such, the computing system110may be configured to control actuation of each of the drive assembly and the actuator assembly52. Likewise, the computing system110may be operably coupled with the image forming apparatus64to place the radiant energy device20in one or more positions. Various sensors130may be provided for detecting information related to movement of the stage18, the resin support26and/or the radiant energy device20. The information may be provided to the computing system110, which, in turn, can alter a movement characteristic of the stage18, the resin support26and/or the radiant energy device20in order to maintain the locus of the components relative to one another.

It should be appreciated that the additive manufacturing apparatus is described herein only for the purpose of explaining aspects of the present subject matter. In other example embodiments, the additive manufacturing apparatus may have any other suitable configuration and may use any other suitable additive manufacturing technology. Further, the additive manufacturing apparatus and processes or methods described herein may be used for forming components using any suitable material. For example, the material may be plastic, metal, concrete, ceramic, polymer, epoxy, photopolymer resin, or any other suitable material that may be embodied in a layer of slurry, resin, or any other suitable form of sheet material having any suitable consistency, viscosity, or material properties. For example, according to various embodiments of the present subject matter, the additively manufactured components described herein may be formed in part, in whole, or in some combination of materials including but not limited to pure metals, nickel alloys, chrome alloys, titanium, titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys, iron, iron alloys, stainless steel, ceramic oxides, and nickel or cobalt based superalloys (e.g., those available under the name Inconel® available from Special Metals Corporation). These materials are examples of materials suitable for use in the additive manufacturing processes described herein, and may be generally referred to as “additive materials.”

Aspects of the invention(s) are provided by the subject matter of the following clauses, which are intended to cover all suitable combinations unless dictated otherwise based on logic or the context of the clauses and/or associated figures and description:

A method, comprising: moving a grid projected by an additive manufacturing apparatus so that a first border of a tile of the grid aligns with a first boundary of a layer to be printed; flashing, with the grid positioned so that the first border of the tile aligns with the first boundary of the layer to be printed, pixels of the tile that are positioned substantially within a perimeter of the layer to be printed; moving the grid so that a second border of the tile aligns with a second boundary of the layer to be printed; and flashing, with the grid positioned so that the second border of the tile aligns with the second boundary of the layer to be printed, pixels of the tile that are i) positioned substantially within the perimeter of the layer to be printed; and ii) aligned at least in part with an unflashed area of the layer.

The method of any clause provided herein, wherein when moving the grid so that the first border of the tile of the grid aligns with the first boundary of the layer to be printed, at least one side border of the tile is aligned with a side boundary of the layer.

The method of any clause provided herein, wherein a given pixel of the pixels of the tile is positioned substantially within the perimeter of the layer to be printed when at least a predetermined area percentage of the given pixel is within the perimeter of the layer to be printed.

The method of any clause provided herein, wherein the predetermined area percentage is seventy-five percent (75%).

The method of any clause provided herein, wherein the predetermined area percentage is eighty-five percent (85%).

The method of any clause provided herein, wherein the predetermined area percentage is ninety-five percent (95%).

The method of any clause provided herein, wherein the predetermined area percentage is one hundred percent (100%).

The method of any clause provided herein, wherein in flashing, with the grid positioned so that the second border of the tile aligns with the second boundary of the layer to be printed, only the pixels of the tile that are i) positioned substantially within the boundary of the layer to be printed; and ii) aligned at least in part with an unflashed areas of the layer, wherein the unflashed area has an area that is equal to or greater than a predetermined percentage of an area of a given pixel of the tile are flashed.

The method of any clause provided herein, wherein the predetermined percentage is ten percent (10%).

The method of any clause provided herein, wherein the predetermined percentage is twenty percent (20%).

The method of any clause provided herein, wherein the predetermined percentage is thirty percent (30%).

The method of any clause provided herein, wherein the predetermined percentage is less than about twenty-five percent (25%).

The method of any clause provided herein, wherein the tile is one of a plurality of tiles of the grid, and wherein the method further comprises: determining whether the layer to be printed fits within a single tile of the plurality of tiles of the grid, wherein when the layer to be printed fits within a single tile, the grid is moved so that the first border of the tile of the grid aligns with the first boundary of the layer to be printed.

The method of any clause provided herein, further comprising: determining whether the layer to be printed is complete, wherein when the layer to be printed is determined not to be complete, the method further comprises iteratively: moving the grid so that a subsequent border of the tile aligns with a subsequent boundary of the layer to be printed, the subsequent border being different than the first border, the second border, and any border of the tile previously aligned with one of the boundaries of the layer to be printed, the subsequent boundary of the layer to be printed being different than the first boundary, the second boundary, and any boundary of the layer to be printed not yet aligned with a border of the tile; and flashing pixels of the tile that are i) positioned substantially within the perimeter of the layer to be printed; and ii) aligned at least in part with an unflashed area of the layer.

The method of any clause provided herein, further comprising: determining whether the layer to be printed is complete, wherein when the layer to be printed is determined to be complete, the method iterates the method of claim1for subsequent layers to build up a component.

An additive manufacturing apparatus, comprising: a radiant energy device; and a computing system having one or more processors, the one or more processors being configured to: cause a grid projected by the radiant energy device to move so that a first border of a tile of the grid aligns with a first boundary of a layer to be printed; cause the radiant energy device to flash, with the grid positioned so that the first border of the tile aligns with the first boundary of a layer to be printed, pixels of the tile that are positioned substantially within a perimeter of the layer to be printed; cause the grid to move so that a second border of the tile aligns with a second boundary of the layer to be printed; and cause the radiant energy device to flash, with the grid positioned so that the second border of the tile aligns with the second boundary of the layer to be printed, the pixels of the tile that are i) positioned substantially within the perimeter of the layer to be printed; and ii) aligned at least in part with an unflashed area of the layer.

The method of any clause provided herein, wherein when moving the grid so that the first border of the tile of the grid aligns with the first boundary of the layer to be printed, at least one side border of the tile is aligned with a side boundary of the layer.

The method of any clause provided herein, wherein a given pixel of the pixels of the tile is positioned substantially within the perimeter of the layer to be printed when at least a predetermined area percentage of the given pixel is within the perimeter of the layer to be printed.

A non-transitory computer readable medium comprising computer-executable instructions, which, when executed by one or more processors of a computing system associated with an additive manufacturing apparatus, cause the one or more processors to: cause a grid projected by a radiant energy device of the additive manufacturing apparatus to move so that a first border of a tile of the grid aligns with a first boundary of a layer to be printed; cause the radiant energy device to flash, with the grid positioned so that the first border of the tile aligns with the first boundary of a layer to be printed, pixels of the tile that are positioned substantially within a perimeter of the layer to be printed; cause the grid to move so that a second border of the tile aligns with a second boundary of the layer to be printed; and cause the radiant energy device to flash, with the grid positioned so that the second border of the tile aligns with the second boundary of the layer to be printed, the pixels of the tile that are i) positioned substantially within the perimeter of the layer to be printed; and ii) aligned at least in part with an unflashed area of the layer.

The non-transitory computer readable medium of any clause provided herein, wherein the one or more processors are further configured to: determine whether the layer to be printed is complete; and determine whether an additional layer is to be printed.