High-speed laser process for 3D printing of parts

Abstract

A part (27) 3D printed by a pulse-raising device (200). The part has predetermined features including multiple 3D prints (29) and voids of a grid pattern. The grid pattern includes multiple positions arranged along a series of substantially parallel columns, each position including either one 3D print or one void. Pulses from the pulse-raising device form the 3D prints, and the absence of pulses forms the voids. The pulse-raising device is controlled by a computing device that sends a packet of instructions to the pulse-raising device, each packet of instructions including at least two, each of which instructs the laser (20) to pulse-drive or not pulse-drive, and respectively generates a 3D print or void at each position on the grid pattern.

Description

[Technical Field]

[0001] This invention relates to a process for forming 3D products using a high-speed pulsed laser. [Background technology]

[0002] Short-pulse laser decoration utilizes energy from nano, pico, and femto short-pulse lasers across various wavelengths and energies to 3D print parts such as products, components, and / or packages. Importantly, the laser technology used in short-pulse laser 3D printing is a high-throughput technique that employs a fixed laser source, where the laser beam is directed towards the product, component, or package being 3D printed by electronically / mechanically controlled mirrors (i.e., "Garbo" sets) and lenses (i.e., F-theta and similar lenses).

[0003] There is considerable interest in the possibilities presented by laser 3D printed parts, such as those produced by short-pulse laser 3D printing. While lasers are improving, with newer lasers offering a variety of energies and wavelengths, these 3D printing processes can still be slow and expensive.

[0004] Current state-of-the-art laser 3D printing processes include "raster" 3D printing processes and "vector" 3D printing processes, which are either high-speed but have low precision and resolution, or low-speed but have high precision and resolution. A combination of high speed and high precision does not exist in prior art. This problem is particularly pronounced when 3D printing large parts. Raster laser 3D printing processes print in a grid, and parts are 3D printed row by row, point by point by the laser. Each pulse is "gate-controlled" so that the pulse is emitted only to dark pixels of the image and not to bright pixels of the image (or vice versa). Each pulse is individually gate-controlled, and the pulse energy of each pulse can be varied to produce a grayscale image. State-of-the-art raster 3D printing processes are effectively limited to lasers with repetition rates of around 100 kHz, considering the practical limitations of the approximately 10 uS update rate when signaling the laser's on / off function (i.e., "gating"). Speed ​​increases can only be achieved by increasing the pulse interval, which can come at the expense of fine details such as those required for 3D printing small font text and graphics.

[0005] State-of-the-art vector 3D printing processes can run at over 100 kHz because pulses are typically gated open while the laser beam is "directed" (by mirrors) to the shape of the vector lines being 3D printed. Vector 3D printed parts containing text are often recognizable because the 3D printed lines are typically one pulse width (unless filled in), and the pulses converge near corners where the surface velocity of the laser beam slows down as it turns the corner. However, it has been found that the accuracy of 3D printing placement using vector 3D printing is compromised when the surface velocity of the laser beam is very high.

[0006] There are various manufacturing methods for creating 3D structures, and laser oscillators play a central role in the 3D build-up process. Common terms include laser 3D printing (or 3D laser printing) and stereolithography. Terms like selective laser melting (SLM) or selective laser sintering (SLS) refer to processes in which solid materials are formed. Another technique is known as laser metal deposition (LMD), in which powder is coaxially fed through a nozzle to a focused laser spot, allowing for the production of functional metal parts with sufficient density. Another laser technique, known as stereolithography (SLA), uses shorter wavelength lasers to locally photopolymerize liquids.

[0007] Two main attractions of 3D laser printing are its ability to manufacture numerous different parts without creating any special tools, and its ability to produce a wide range of different parts. Only the laser oscillation command needs to be changed; there is no need to create special tools or methods. In other words, only software needs to be adjusted, not hardware or general manufacturing strategies.

[0008] Another advantage of 3D printing is its ability to flexibly manufacture objects with complex shapes without first creating specialized manufacturing tools such as dies. 3D printers are highly versatile manufacturing machines that directly translate software structures into physical objects. Such printing processes have been developed for a range of materials, including metals, ceramics, and polymers. Constant-wave (CW) and pulsed lasers with wavelengths that are activated, absorbed, or otherwise suited to the material being printed are used in these applications. For example, a wavelength of 1064 nm can be used for metal melting / sintering, while 355 nm UV can be used for photopolymerization.

[0009] It is possible to create structures that are nearly impossible to manufacture by other methods. The capabilities of the manufacturing method allow for much greater design freedom than usual, and much less so. For example, it is possible to manufacture parts containing open channels with fairly complex shapes that cannot be manufactured by, for example, drilling. Sometimes, a number of such openings can help efficiently cool mechanical parts with some fluid flow through cooling channels.

[0010] SLA processes fall into three main categories: laser-based stereolithography (laser SLA), digitally processed stereolithography (DLP-SLA), and mask SLA (MS1A). In all of these processes, a vat of photoreactive liquid resin is selectively exposed to light to form very thin solid layers that stack to create a single solid object.

[0011] Laser-based SLA was the first method of stereolithography, developed in 1986 by Charles Hull, co-founder of 3D Systems. This technique works by using a UV laser to draw each layer of an object, using two mirrors (one on the X-axis and one on the Y-axis) driven by a motor known as a galvanometer or "garbo" to rapidly target the laser beam across the printing area, solidifying the resin as the laser beam moves. To create a solid object, the design must be broken down layer by layer into a series of points and lines given to the "garbo" as a set of coordinates, which the laser then traces.

[0012] DLP-SLA uses a digital projector to expose a single image for each layer across the entire platform at once. Because each layer's image is digitally displayed, it consists of numerous square pixels, resulting in layers formed from small rectangular bricks called voxels that stack along the Z-axis. Examples of DLP-SLA orthodontic 3D printers include Park Dental Research / Orchestrate Juell Flash OC and Envisiontec Vida.

[0013] An extreme example of 3D printing application is the manufacture of essential components for rocket engines. The opportunity to create complex computer-designed structures optimized for gas flow and stability despite minimal weight is significant, while limitations such as material cost and processing time are less critical.

[0014] Rapid manufacturing is also useful for replacement parts. Especially when model cycles are relatively short and new types of parts are constantly needed, manufacturing and stocking a sufficient number of replacement parts for various types of machines is generally not very economical. With 3D laser printing, only the recipe is stored in a computerized form, and such replacement parts can be produced on demand.

[0015] Therefore, the need for faster, more economical, and more accurate laser 3D printing still exists. Both the hardware and software that control the raising device can also improve how these improved raising devices are used. Furthermore, the placement of laser 3D prints on parts can be improved to provide both precision and speed.

[0016] Therefore, it is desirable to provide software for operating the raising device and a process for 3D printing parts at high speed and with high precision (such as directly reproducing label information, aesthetic features, and functional features) together with the improved raising device. These improvements should make the process fast, simple, cost-effective, and scalable to mass production, and the resulting parts should have consumer-readable and machine-readable features that can replace labels and adhesives, among other advantages. [Overview of the Initiative] [Means for solving the problem]

[0017] The present invention provides solutions to one or more of the shortcomings of the prior art, as well as other advantages. This specification, claims, and drawings describe various features and embodiments of the present invention, including 3D parts printed by a pulse-raising apparatus. The parts have a series of overlapping layers, each layer having multiple 3D prints. Pulses from the pulse-raising apparatus form the 3D prints, and the absence of pulses forms voids.

[0018] In one embodiment of the present invention, a pulse-raising device is controlled by a computing device that transmits instruction packets to the pulse-raising device, the instruction packets comprising at least two individual instructions. Each individual instruction instructs the laser to pulse-drive or not pulse-drive, and the overlapping layers comprise a 3D print and voids of a grid pattern. The grid pattern consists of a plurality of positions arranged along a series of substantially parallel columns, each position comprising one of the 3D prints. Furthermore, pulses from the pulse-raising device form the 3D prints, and the absence of pulses forms voids. Each individual instruction instructs the laser to pulse-drive or not pulse-drive, respectively generating a 3D print or void at each position on the grid pattern. The grid pattern has positions arranged along columns, with each pair of adjacent positions separated by an X distance, and there are two or more substantially parallel columns, with each adjacent pair of substantially parallel columns separated by a Y distance.

[0019] In another embodiment, the Y distance is greater than the X distance, and the positions between adjacent parallel columns may be stacked or offset. Similarly, the positions of the two-dimensional layers may be stacked or offset in the Z direction. Each instruction within a packet may be any combination of 3D printing and voids, including all 3D prints or all voids.

[0020] In yet another embodiment of the present invention, there is a method for 3D printing a part using a pulse-raising apparatus, the method comprising defining a series of overlapping layers comprising a plurality of 3D prints and voids of a grid pattern, wherein the grid pattern comprises a plurality of positions arranged along a series of substantially parallel columns, each position comprising either one 3D print or one void.

[0021] The method further includes the steps of forming 3D prints by pulse-driving a pulse-raising device and generating voids by not pulse-driving the pulse-raising device, and controlling the pulse-raising device with a computing device that sends instruction packets to the pulse-raising device. Each instruction packet comprises at least two individual instructions, each instruction informing the pulse-raising device whether to pulse-drive or not, thereby generating 3D prints or voids at each position on the grid pattern, respectively. At least one of the columns is 3D printed by two different packets. Alternatively, at least one of the columns is 3D printed by three different packets. Each instruction packet further comprises two or fewer, preferably only one, individual instructions related to the position of a location in the grid pattern.

[0022] The present invention offers many advantages over the prior art, including the ability to 3D print objects or parts with much higher precision and at much faster speeds than previous pulse-raising 3D printing methods. [Brief explanation of the drawing]

[0023] [Figure 1] It is a schematic diagram of a raising device according to the present disclosure. [Figure 2] It is a lattice according to the present disclosure, in which the positions of adjacent parallel columns are stacked. [Figure 3] It is a lattice according to the present disclosure, in which the positions of adjacent parallel columns are offset. [Figure 4A] It is an alphanumeric of a lattice pattern 3D printed according to the present invention. [Figure 4B] It is an alphanumeric of a lattice pattern 3D printed according to the prior art process. [Figure 5] It is a diagram showing a standardized rectangular pattern laser printed by a prior art vector laser process compared with the same pattern laser printed according to the present invention. [Figure 6] It is an exemplary lattice of a standardized rectangle according to the present invention. [Figure 7] It is a diagram showing the %Mismark calculation. [Figure 8] It is a diagram showing a 3D print created as a result of a packet of information sent to a laser controller according to the present invention. [Figure 9] It is a diagram showing a 3D print created as a result of a packet of information sent to a laser controller according to the present invention. [Figure 10] It is a diagram showing a 3D print created as a result of a packet of information sent to a laser controller according to the present invention. [Figure 11] It is a diagram showing a 3D print created as a result of a packet of information sent to a laser controller according to the present invention. [Figure 12] It is a diagram showing the "stage" method of 3D printing using a laser. [Figure 13] It is a diagram showing an inverted method of 3D printing using a laser.

Mode for Carrying Out the Invention

[0024] 3D printing operation 3D laser printing methods generally work using a bath of liquid or powder with a smooth surface. A laser beam is then moved across the surface, irradiating only a portion of it while avoiding other areas, thereby causing solidification. Often, the laser beam is moved along a line in any direction; this is called the vector method. In other cases, the entire area is systematically scanned, and the laser beam is turned on only over the portion to be processed; this is called the raster method. These methods may also be combined; for example, vector scanning of the contour followed by raster scanning of the interior portion.

[0025] A flat structure is slightly lowered into a bath so that its surface is covered with a thin layer of liquid or powder. Swiping the surface with a solid object can help to obtain a smooth surface in the bath. A laser can then be used to fabricate a layer of solid material on the flat structure. This process is repeated until the desired height of the solid workpiece is achieved.

[0026] Figure 13 shows the “stage” method of 3D laser printing. Both the raising device 301 and the stage 303 are controlled by a computing system 305. The computing system 305 raises and lowers the stage 303 in the Z direction 307. The stage 303 initially starts near the top of the liquid 306 contained in the vat 302. The raising device 301 starts by selectively laser curing a portion of the liquid 306 on the stage 303 to form the first layer of the part 304. Once the first layer is complete, the stage 303 is lowered slightly into the vat 302, allowing a new layer of liquid to cover the part 304. The raising device 301 then repeats the selective laser curing of the liquid 306 for a second layer of the part 304. Those skilled in the art will understand that the thickness of each individual layer is determined by the type and power of the laser used, as well as the complexity of the part to be printed. Also, each sequential layer may be the same as or different from the layer below it, depending on the design of the desired part. Although the term "liquid" is used in the explanation of Figure 13, those skilled in the art will understand that the liquid may also be finely granulated metal particles.

[0027] The manufactured pieces are then removed from the bath, any remaining liquid or powder is removed, and, if necessary, some additional processes such as polishing are applied to improve surface quality. The remaining untreated powder or liquid can be used for the next parts to be manufactured.

[0028] Another possibility is that the irradiation is carried out from the bottom, for example, through a glass plate below the bath. The fabricated workpiece is then gradually lifted upward to allow new powder or liquid to reach its bottom.

[0029] Figure 14 shows 3D printing of an inverted head (part 321) using a glass plate 326. The base 322 begins near the glass plate 326, with a thin layer of liquid 323 between them. The liquid 323 is contained in a vat 325. The lathing device 320 selectively hardens a portion of the liquid 323 on the base 322 to form the first layer of part 321. Next, the base 322 is moved in the Z direction 324 to allow a new layer of liquid 323 to flow between the glass plate 326 and part 321. The lathing device 320 then hardens the new layer of liquid 323 to form the next layer on part 321. Both the lathing device 320 and the base 322 are controlled by a computing device (not shown). As with the step-by-step 3D printing in Figure 13, those skilled in the art will understand that the thickness of each individual layer is determined by the type and power of the laser used, as well as the complexity of the part being printed. Furthermore, each continuous layer may be the same as or different from the layer below it, depending on the design of the desired component. Although the term "liquid" is used in the explanation of Figure 14, those skilled in the art will understand that the liquid may also be finely granulated metal particles.

[0030] Other methods exist in which the curing of a liquid is achieved below the top of the liquid. Such methods may include subsurface curing of liquids using a confocal lathing apparatus. In such a method, the laser focal point is below the top of the liquid, and as a result, the fluence of the laser spot required to cure the liquid is achieved below the top surface of the liquid.

[0031] Other methods exist for continuously supplying raw materials during the process using some kind of supply mechanism. Such processes are generally carried out by certain types of 3D laser printing equipment and are largely automated. Nevertheless, some degree of manual work is often required, for example, to fill the bath, remove the workpiece, and clean it.

[0032] Lasers suitable for SLA include pulsed fiber lasers and other solid-state lasers. When 3D printing metal, an inert gas such as nitrogen or argon is usually required to protect the metal from oxidation.

[0033] To melt polymer materials, a CO2 laser with a wavelength of 10.6 μm is often used. Such light is typically well absorbed by polymers. It is common practice to heat the entire bath with a separate infrared source, resulting in relatively low laser power and a weaker temperature gradient. This helps to obtain better quality results.

[0034] Another possibility is to use laser-induced polymerization. Here, the original material is a liquid containing several monomers, and short-wavelength light (e.g., a 355 nm pulsed laser) is used to trigger several activators to initiate polymerization.

[0035] While 3D manufacturing processes for ceramics are not as developed as those for metals and polymers, different processes are possible. For example, a suspension or paste that can exhibit a sufficiently uniform distribution of ceramic particles (e.g., alumina or zirconia) can be used as a raw material. Such a suspension may contain a photocurable organic binder material. The bonding of ceramic particles by radical polymerization of the binder material can be initiated, for example, using blue laser light.

[0036] parts As used herein, “component” refers to an individual object being manufactured. A component may be a container, and non-limiting examples include bottles, bags, wraps, drums, jars, cups, caps, etc. A component may be formed from any of a variety of common materials, including: polymers (i.e., PET, PETG, HDPE, PP, PVOH, LDPE, LLDPE, engineered resins), metals (i.e., aluminum, steel, or other alloys), ceramics, and glass.

[0037] The parts manufactured by the 3D printing process of the present invention are intended to be three-dimensional, and it is understood that they are manufactured by a series of two-dimensional layers. Therefore, although this specification refers to grids and two-dimensional printing, it is understood that this applies to the printing of two-dimensional layers of a 3D part. For example, a 3D part may consist of a series of overlapping layers obtained from two-dimensional laser printing. That is, two-dimensional layers laser-printed on a two-dimensional grid are superimposed to form a 3D part.

[0038] The components according to the present invention may be formed in one or more suns from a single thermoplastic material or resin, or from two or more different materials. For example, the components may be made from polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polystyrene (PS), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene naphthalate (PEN), polycyclohexylenedimethylene terephthalate (PCT), glycol-modified PCT copolymer (PCTG), copolyester of cyclohexanedimethanol and terephthalic acid (PCTA), polybutylene terephthalate (PBCT), acrylonitrile styrene (AS), styrene butadiene copolymer (SBC), or polyolefins, such as low-density polyethylene. The components may include one or more thermoplastic resins selected from the group consisting of polyethylene (LDPE), linear low-density polyethylene (LLPDE), high-density polyethylene (HDPE), propylene (PP), and combinations thereof. Similarly, the components may include engineered resins, ceramics, or metals.

[0039] There are various polymer resins available for use in SLA (stereolithography) 3D laser printing. The materials used in SLA include, but are not limited to, PLA, ABS, nylon, resin, PETG, TPU, ASA, and PEI (engineered plastics), and are photosensitive thermosetting polymers supplied in liquid form.

[0040] Metal structures can be manufactured from various types of steel, or alloys of nickel, titanium, or aluminum. Powders containing particles of only one type of metal, or mixtures of different materials, can be used, with only one of them being melted while the other metal particles are held together. This technique is also called selective laser melting.

[0041] Instead of laser melting, laser sintering can be used. Here, the laser does not completely melt the material, but merely burns the powder particles together. In the case of metal powders, this method is also called direct metal laser sintering. A wide range of materials can be used with this approach. However, sintered materials usually still exhibit some degree of significant porosity, i.e., lower density and weaker mechanical strength.

[0042] The modified method is indirect sintering or two-stage sintering, where laser treatment forms only a preliminary porous structure, which is then sintered again by heat treatment. This process allows for the introduction of another metal with a lower melting point (e.g., copper), which fills the microscopic voids in the porous structure of the other metal (e.g., steel). In this way, substantial shrinkage of the structure is avoided.

[0043] Thermoplastic materials may include monomers derived from renewable resources and / or monomers derived from non-renewable resources (e.g., petroleum) or combinations thereof. For example, thermoplastic resins may include polymers made entirely from bio-derived monomers, or polymers made partly from bio-derived monomers and partly from petroleum-derived monomers.

[0044] In some cases, parts manufactured by 3D printing are not made for direct use but serve only to create molds, which can then be used to produce more parts, replicas, from different materials through some form of casting. The replicas, in this case, can be made from very stable materials that are not easily used directly in 3D printing. However, this method severely limits the range of possible shapes because it cannot replicate the internal structure in the same way.

[0045] Tooling is also a preferred use of 3D laser printing. Tooling refers to the production of manufacturing tools such as casting molds or workpiece fixing tools. Standard tools are available for many processes, although some processes require highly specialized tools, but often not in large quantities, for example, one tool may be used to produce many items of the final product.

[0046] Laser and Raising Equipment To 3D print parts according to the present invention, pulsed lasers, such as short-pulse lasers, may be used. Lasers for use in the present invention are commercially available and include nanosecond, picosecond, and femtosecond lasers. These short-pulse lasers can emit pulses applied at high energy density and high repetition rates, and the high energy and high repetition rate are important to enable laser 3D printing of parts at high speed. Laser 3D printing itself includes 3D printing in which materials are made by melting, photopolymerizing, or photocuring materials to form objects such as products, parts, or packages.

[0047] Any suitable laser can be used to 3D print part 10. Figure 1 shows an example of a lathing apparatus 200 equipped with a laser 20 useful for 3D printing on a part according to the present invention. The lathing apparatus 200 includes laser 20, which may be any laser capable of generating sufficient energy to 3D print a part, such as a UV laser having an output in the range of 1W to 60W and a laser wavelength of 355 nanometers, or an IR 3D printing laser having an output in the range of 1W to 300W, and even 500W, and a laser wavelength of 1064 nanometers. Such lasers are available from various suppliers, including the IPG ULPN-355-10-1-3-M 3D printer or YLPN-1-1x350-50-3M MOPA module available from IPG Photonics of Oxford, MA, United States. Other forms and types of lasers are also possible, and different output ranges and settings may be used. The raising device may, if desired, include an optical system that can be used to direct the laser beam and / or modify the laser beam by changing the energy density and / or spot size of the laser beam 28.

[0048] Frequency, or repetition rate, measured in Hz, is the number of laser pulses a single laser can deliver per second. For example, a 1 MHz laser delivers 1,000,000 pulses / second, and a laser with a repetition rate of 100 kHz delivers 100,000 pulses / second. The repetition rate can be important for processing certain lazing jobs (i.e., high-speed laser 3D printing) in a short amount of time. More pulses available per unit time correlate almost linearly (inversely) to the time required to 3D print a given column for a particular job.

[0049] Pulse energy is the amount of energy contained in a single laser pulse and is typically measured in μJ or mJ. Typically, pulse energy is in the range of 0.001 μJ to 3000 μJ, more preferably 0.1 μJ to 2000 μJ, more preferably 0.1 μJ to 1000 μJ, more preferably 5 μJ to 1000 μJ (2 mJ), more preferably 7 μJ to 1000 μJ, and more preferably 10 μJ to 300 μJ. The average output of the laser is then given as pulse energy × repetition rate. Average power = pulse energy (J) * Repeat rate (Hz or 1 / second).

[0050] Peak power is equal to the pulse energy divided by the pulse duration, which can be less than 100 nanoseconds, less than 50 nanoseconds, less than 20 nanoseconds, less than 10 nanoseconds, or less than 1 nanosecond. Therefore, pulse energy and pulse duration are linearly related to peak power. Shorter pulse durations achievable with nanosecond, picosecond, and femtosecond lasers enable very high peak power, which is useful for the ability to 3D print parts.

[0051] In the lathing apparatus 200 depicted in Figure 1, the laser 20 projects a laser beam 28 onto an X-mirror 22 rotated by an X-Garbo 21. The X-mirror 22 and X-Garbo 21 collectively form an X-Garbo set. The laser beam 28 is then projected onto a Y-mirror 24 rotated by a Y-Garbo 23. The Y-mirror 24 and Y-Garbo 23 collectively form a Y-Garbo set. The X-mirror 22 and Y-mirror 24 cooperate to direct the laser beam 28 to the position where the desired 3D print 29 should be 3D printed on the part 27. Before the laser beam 28 reaches the part 27, it typically passes through a lens 26. The distance from the lens 26 to the part 27 is the focal length 25.

[0052] The combined optical system of the lathing device may function to sweep a laser beam across the surface of a part in a series of passes. The laser beam may sweep across the part along a first row in a grid in the X direction, while emitting (or omitting) pulses, and directed by an X-mirror. The combination of the sweep rate of the laser beam across the surface of the part, also called the surface velocity of the laser beam, and the repetition rate of the laser pulses determines the spacing of the 3D prints along the X direction. X interval * Repetition rate = surface velocity

[0053] A laser may emit pulses or multiple pulses while sweeping across a part at a given position, thereby resulting in a 3D printed position(s), or the laser may omit pulses(s) while sweeping across the part at a given position, thereby resulting in an unmarked position(s) (i.e., void(s)). The laser beam may sweep across the part at a constant surface velocity while emitting and / or omitting pulses. The surface velocity or sweep velocity is defined above. The laser beam may then sweep across the part along a second row of the grating (such as a row adjacent to the first row) while emitting (or omitting) pulses. The laser beam may sweep across the first and second rows in the same or opposite directions. For example, the laser beam may sweep across the first row from "left to right" and then sweep across the subsequent / adjacent row from "right to left".

[0054] Laser 3D printing The components of the present invention are typically 3D printed by processes of foaming, carbonization, excision, etching, reduction, oxidation, and / or phase change. The term foaming refers to the process in which a laser beam melts and vaporizes a portion of the material, creating bubbles that are trapped within the molten resin and, upon cooling, diffusely reflect light.

[0055] When carbonizing a material, the laser heats the surface of the material (generally to a minimum of 100°C) and emits oxygen, hydrogen, or a combination of decomposition products. Carbonization generally leads to darker 3D prints with a higher carbon content compared to the original material, making carbonization a good choice for lighter-colored parts, although contrast is rather minimal on darker materials.

[0056] There are additional methods for 3D printing parts. For example, annealing is a unique laser process that can be used on metals and other materials. The energy from the laser beam creates an oxidation process beneath the surface of the material, which results in a change in color on the material's surface.

[0057] Spot size is a key parameter of the laser 3D printing of the present invention and relates to the focused area in contact with the part by the laser beam. "Spot size" is the diameter of a circular spot. Although the spot is circular, it is possible to achieve an elliptical spot by controlling the laser beam optics relative to the part. Spot size can be modified by focusing or defocusing the laser beam, but the "fluence" (energy per unit area) within the spot decreases as the spot is enlarged or defocused. Theoretically, the smallest spot size achievable with any laser is the wavelength of the laser itself. In practice, the smallest spot size achievable with a pulsed laser is about 7 to 20 μm. The spot size of the laser 3D printing of the present invention may be in the range of about 10 μm to about 150 μm, preferably about 20 μm to about 100 μm, more preferably about 30 μm to about 80 μm, and even more preferably about 40 μm to about 60 μm. As discussed in the background technology section, the spot size for conventional laser 3D printing (e.g., using a CO2 laser) is a minimum of 250 μm and can exceed 800 μm. Another way to think about spot size in the context of 3D printing is the size of the paintbrush a painter uses to paint. Smaller spot sizes are used when very fine detail is desired. Larger areas to be covered may prefer larger spot sizes. However, laser 3D printing mechanisms require a minimum fluence to achieve the desired 3D print, and therefore, the balance between pulse energy, pulse duration, pulse overlap, and spot size is crucial.

[0058] Furthermore, while there is an area around the laser contact spot that can be heated during the 3D printing process, the material is hardly or never 3D printed. This "thermal-affected zone" can still result in effects such as crystallization, which can affect the appearance and / or performance of the target material. Short-pulse lasers (e.g., nanosecond lasers) have some thermal-affected zone, but it is substantially smaller than that of microsecond-pulse lasers or CW-type lasers (e.g., CO2, longer-pulse IR lasers). Picosecond and femtosecond lasers are often called "ultrashort pulses" and have little to no thermal-affected zone. This ability helps control the thermal effects of 3D printing.

[0059] The geometric shape of the 3D printing interval is a major contributing factor to the cycle time and fluence (or energy per unit area) provided to the part. For example, the interval between 3D prints may be such that the 3D prints do not overlap at all, or have 0% overlap. With 0% overlap, each individual laser pulse contributes to the energy provided to 3D print the part. If the laser does not have sufficient pulse energy or peak power to achieve the desired 3D print, the pulse interval can be reduced to a point where the spots overlap in either the X and Y directions, or both. Overlapping the spots involves providing two or more laser pulses to the area of ​​the part where the spots overlap, which provides a higher fluence or energy per unit area to that part of the part. In addition, the pulse interval is a major lever for cycle time. If the laser has a fixed repetition rate or pulse frequency, it is desirable to spread the pulses as much as possible while still achieving the desired 3D print type and 3D print contrast in order to achieve the lowest process time (also called cycle time). In one embodiment of the present invention, the pulses do not overlap.

[0060] Pulse duration is the length of time a pulse continuously remains above half its maximum value. Shorter pulses can produce higher peak power at a typical average power output. This is because average power = pulse energy (J). * This is because the pulse rate is measured in Hz or 1 / second. The peak output is equal to the pulse energy divided by the pulse duration. Therefore, when the pulse duration is significantly shorter, the resulting peak pulse output is significantly higher. This peak output allows for improved melting, photopolymerization, or photocuring on the surface being 3D printed. Short-pulse lasers utilize this phenomenon to 3D print parts, enabling 3D printing mechanisms that are typically not found with longer-pulse lasers.

[0061] Packetization One way in which current CV bitmap processes can overcome the 10μs limit update rate is to include multiple individual instructions in a single packet of instructions to the pulse-raising device. These are individual instructions to pulse or not pulse in a single update, resulting in a laser that either emits pulses to form a 3D print or omits pulses, leaving voids. In such a process, each row may include both 3D-printed and non-3D-printed positions according to the instruction packet.

[0062] A constant laser sweep rate ensures that the X-spacing within these chains of multiple 3D prints (or voids) remains consistent. It should be noted that the laser sweep rate is determined as follows: X distance * Repetition rate = surface velocity Increasing the laser repetition rate to 100kHz-200kHz can help double the laser beam sweep speed and reduce cycle time.

[0063] Naturally, including multiple individual instructions in a single update improves the complexity of the patterns that can be generated. A laser 3D printing process that includes only one pulse per update (i.e., employing a laser with a 10μs update rate and a 100kHz repetition rate) can result in the following complexity for a single 3D print or void: 3D printing - void - 3D printing - void - 3D printing - void The same process using a 200 kHz laser has twice the sweep speed, but can only produce the following details: 3D printing - 3D printing - void - void - 3D printing - 3D printing - void - void - 3D printing - 3D printing - void - void

[0064] The current CV bitmap process allows for laser beam sweeping speeds across the surface of a part that are far faster than those achievable with currently available laser 3D printing processes, such as raster 3D printing and vector 3D printing.

[0065] Packets of individual instructions as defined herein may be communicated to the lathing device at regular time intervals, such as every 10 microseconds. Packets of individual instructions as defined herein include 3D print / void information as described above, but each packet may also include additional instructions. For example, an information packet may include individual instructions related to the position of the location to be 3D printed. Those skilled in the art will understand that it is desirable to do two things in order to increase the speed and accuracy of the entire pulsed laser 3D printing process. First, each information packet should contain the maximum number of individual instructions that the processor can allow, and second, the number of instructions related to 3D print / void should be maximized relative to other instruction information within the same packet.

[0066] To illustrate the packetization concept of the present invention, consider a vehicle such as a bus. For example, a given bus may have 2, 4, 8, 16, 32, or 64 or more seats. It is obvious that driving a bus with 16 seats but only 4 passengers from point A to point B is an inefficient use of the bus. Similarly, filling each packet of information with the maximum number of individual instructions increases the efficiency of the overall process. Furthermore, if we have a bus with only 8 seats and fill 3 of these seats with position or position instructions, only 5 seats remain for 3D printing / void instructions, which is the desired outcome of the process.

[0067] The pulsed laser 3D printing process of the present invention operates at a constant laser repetition rate and a constant surface velocity when moving a laser beam across a row of given positions, with a short deceleration / re-acceleration process at the turning points at the ends of each row. During this turning process, the laser does not 3D print. Furthermore, the rows are linear, and therefore, only a change of direction occurs at the ends of each row. During the short turning period, the instruction packets may contain a greater amount of positional information.

[0068] Similarly, with a constant surface velocity and a constant repetition rate, the position along a given column is largely determined at the start of 3D printing, notified by any given packet (i.e., a consistent X distance). Therefore, except for the start and end of each column, each instruction packet may require only one position instruction. The position instruction can include X, Y, and Z components. When laser 3D printing on a flat surface, it is understood that the Z component of the position information can be consistently zero.

[0069] Since the pulsed laser moves at a constant surface velocity, the endpoint of the 3D print, notified by one packet, determines the starting point of the next packet. Thus, one individual command related to position serves a dual purpose: the end position of one packet and the start position of the next. Those skilled in the art will understand that velocity is defined as the distance traveled divided by the time required to travel that distance. Each packet has a set time, and one position command tells the laser how far to move, which defines the velocity. Thus, no additional commands related to velocity are required, freeing up more computational space for 3D print / void command information (e.g., bus seats). This simplification of velocity and position maximizes the number of individual commands related to 3D print and void. This speeds up the entire process and makes it more accurate. This level of efficiency for packet usage cannot be achieved in prior art processes (i.e., rasters, vectors), for example, which draw boundaries and then fill in the spaces between lines. These prior art processes require an additional amount of velocity and position information within each packet of information.

[0070] Therefore, a part can be 3D printed by a pulse-raising device to produce a predetermined feature comprising multiple 3D prints and voids of a grid pattern. The grid pattern is formed at multiple positions arranged along a series of substantially parallel columns, each position comprising either one 3D print or one void. Pulses from the pulse-raising device form the 3D prints, and the absence of pulses forms the voids. The pulse-raising device is controlled by a computing device that sends instruction packets to the pulse-raising device, each instruction packet comprising at least two, preferably at least four, more preferably at least eight, even more preferably at least sixteen, or even more than at least 32, or at least 64 or more individual instructions, each of which informs the laser whether or not to emit pulses toward the surface, thereby generating a 3D print or void at each position on the grid pattern, respectively. The instruction packets may be provided to the raising device at an update rate of 10 μs. The refresh rate at which packets can be provided to the raising device may be less than 10 μs, preferably 7.5 μs, or 5 μs, or even 2.5 μs (μs = microsecond).

[0071] Figure 8 shows an example of one column of a grid pattern having packets P1, P2, P3, and P4, each containing two individual commands to a pulse-raising device. P1 commands the pulse-raising device to generate two pulses to form two 3D prints. P2 commands the pulse-raising device to not generate two pulses to leave two voids. P3 commands the pulse-raising device to generate one pulse, then one pulse not to generate, to produce one 3D print and leave one void. P4 commands the pulse-raising device to do the reverse of P3. Those skilled in the art can use this system of 3D printing and voids of grid patterns to form any of a variety of predetermined features as defined herein.

[0072] Figure 9 is an example of one column of a grid pattern having packets P1, P2, P3, and P4, each containing four individual commands to a pulse-raising device. P1 commands the pulse-raising device to generate three pulses and one non-pulse, producing three 3D prints and one void. P2 commands the pulse-raising device to generate two pulses, then two non-pulses, producing two 3D prints and leaving two voids. P3 commands the pulse-raising device to generate one pulse, then a non-pulse, then another pulse, then a non-pulse, producing a 3D print-void-3D print-void pattern. P4 commands the pulse-raising device to generate three non-pulses, then one pulse, producing three voids and one 3D print.

[0073] Figure 10 shows an example of one column of a grid pattern having packets P1 and P2, each containing eight individual commands to a pulse-raising device. P1 commands the pulse-raising device to generate two pulses, not generate a pulse, generate a pulse, not generate a pulse, generate two pulses, and not generate a pulse. P2 commands the pulse-raising device to generate eight pulses. It is understood that prior art polygon scanners can send more than two commands to a pulse-raising device. However, the commands are either all pulse-generating or all non-pulse-generating. For example, a polygon scanner can send eight on-pulses and then eight no-pulse commands. These prior art polygon scanners cannot send individual commands according to the present invention. Those skilled in the art will understand the greatly improved versatility achieved by controlling each and every position using 3D printing or voids, as taught by the present invention. By utilizing the individual packetized commands of the present invention, predetermined features can be 3D printed on a surface with astonishing speed and precision.

[0074] Figure 11 shows an example of one column of a grid pattern having a packet P1 containing 16 individual instructions to a pulse-raising device. P1 instructs the pulse-raising device to generate two pulses, followed by two pulse-non-generations. This pattern is repeated three more times for a total of 16 individual instructions within a single information packet.

[0075] This specification further provides a method for 3D printing a part using a pulse-raising apparatus, the method comprising the following steps: First, defining a predetermined feature of a grid pattern comprising a plurality of 3D prints and voids, wherein the grid pattern comprises a plurality of positions arranged along a series of substantially parallel columns. Each position comprises either one 3D print or one void. The pulse-raising apparatus is then pulse-driven to form the 3D prints and the pulse-raising apparatus is not pulse-driven to generate the voids. Naturally, the voids are not "generated," but rather the positions that are not 3D printed, as defined herein as "voids," are simply left. The pulse-raising apparatus is controlled by a computing device that transmits a packet of instructions to the pulse-raising apparatus, the packet of instructions comprising two, preferably four, more preferably eight, and even more preferably sixteen or more individual instructions. Each of the individual instructions informs the pulse-raising apparatus whether to pulse-drive or not, and respectively generates a 3D print or a void at each position on the grid pattern.

[0076] lattice As used herein, “grid” or “bitmap grid” is interpreted to mean a regular, periodic array of positions that may contain multiple laser-guided prints. The array of prints may be formed within the grid as two-dimensional layers in the X and Y directions, and a series of two-dimensional layers may be superimposed in the Z direction to form a 3D part. The periodicity of the array includes periodicity in both the X and Y directions. Multiple 3D prints within the grid may or may not be present at each of the positions within the grid. That is, 3D prints may or may not be formed at a position within the grid (i.e., voids). As mentioned, the lathing apparatus sweeps the laser beam across the part while either laser pulses are being emitted from the laser or no pulses are being emitted. 3D-printed positions occur when the laser pulses at a given position, and unmarked positions occur when the laser does not pulse at a given position. The laser beam can be swept across the part at a constant surface velocity while the laser repetition rate is constant. Therefore, the periodicity of the position will be regular (i.e., X-distance) in the direction the laser beam is swept across the part (i.e., the X-direction), even if the spacing between 3D printed positions is not equal, considering the possibility of unmarked positions. For unmarked positions, the distance between any 3D printed positions along the same direction (i.e., the X-direction) can be an integer (i.e., 2, 3 or more) of the smallest distance measured between 3D prints in that direction.

[0077] The laser beam can be swept across parts in subsequent rows. The laser beam can be swept from left to right or right to left, and as it moves from row to row, it can be swept in the same direction (e.g., carriage return on a typewriter in a raster process), or it can be swept in alternating directions as it moves from row to row. A major contributing factor to reducing cycle time is sweeping the laser beam in alternating directions as it moves from row to row. Rows can be approximately parallel to each other. The distance between adjacent rows is the Y distance. The positions of adjacent rows can be directly above / below each other, or offset from each other. An offset equal to the X distance is understood to result in realignment of the positions between rows.

[0078] As discussed earlier, laser 3D printing may not overlap in order to reduce the time required to 3D print a given pattern (i.e., "time to print"). Time to print can be further reduced by spacing the 3D prints in either or both the X and / or Y directions, but this increased spacing may lead to poor coherence of the print and a fragile and / or highly porous 3D part. For example, increasing the X distance allows for a faster surface velocity of the laser beam across the surface of the part when 3D printing a given row (at a constant repetition rate). Increasing the Y distance allows for fewer inversions in the process of 3D printing a given given pattern. Alternatively, the 3D prints may be in contact or even overlap to increase the strength of the resulting 3D part and / or reduce porosity.

[0079] The X distance is preferably in the range of about 0.005 mm to about 0.500 mm, more preferably in the range of about 0.010 mm to about 0.100 mm, and even more preferably in the range of about 0.040 mm to about 0.075 mm. The Y distance is preferably in the range of about 0.010 mm to about 2.0 mm, more preferably in the range of about 0.050 mm to about 0.150 mm, and even more preferably in the range of about 0.060 mm to about 0.075 mm.

[0080] Figures 2 and 3 all illustrate various depictions of the grid according to the present invention. More specifically, Figure 2 is a grid 39 according to the present invention, showing the X direction 30, Y direction 32, X distance 31, and Y distance 33. Potential 3D print positions 36 are depicted by empty circles that make up the grid. Furthermore, in Figure 2, a position 36 in a parallel column 38 is "stacked" when the angle 35 between the position in the adjacent column 34 drawn in the Y direction between two potential 3D print positions and the X direction 30 is approximately 90 degrees. In other words, when vectors are used to connect adjacent 3D prints from an array to form a parallelogram (i.e., a unit cell), the positions are stacked when the interior angles of the parallelogram are approximately 90 degrees. If the interior angles of the parallelogram are different from 90 degrees (i.e., 120 degrees and 60 degrees), the positions are offset. The X distance is measured from the center of one position to the center of an adjacent position in the X direction.

[0081] Those skilled in the art will understand that a unit cell of a grid has four axes of symmetry: horizontal, vertical, and two diagonal lines. Laser 3D printing as discussed herein can be performed along any of these four axes.

[0082] Figure 3 shows another grid 49 according to the present invention, which shows an offset 44 having an offset distance 47 between adjacent parallel columns 48. The offset 44 is defined by an angle 45 between a position 46 in one column 48 and the nearest position 46 in the adjacent column 48, and the offset 44 exists when the angle 45 is greater than or less than 90 degrees. Figure 3 further shows the X direction 40, the X distance 41, the Y direction 42, and the Y distance 43.

[0083] The periodicity of the positions constituting the grid includes periodicity in the X direction and periodicity in the Y direction. The X and Y directions can be approximately orthogonal to each other. As depicted in Figures 2 and 3, grids 39 and 49 can take the form of being evenly spaced along consecutive parallel columns, respectively. The direction parallel to consecutive parallel columns is the X direction (30, 40), and the direction approximately perpendicular to the X direction is the Y direction (32, 42). The distance between adjacent positions along any parallel column (e.g., in the X direction) is considered the X distance (31, 41), and the distance between adjacent parallel columns is considered the Y distance (33, 43).

[0084] The grid 39 can be a stacked grid as depicted in Figure 2. In a stacked grid, the positions where 3D printing can be applied along the first column are directly above the positions along the second column that are directly below the first column. In other words, the angle 35 formed between the column segment connecting the first position along the first column to an adjacent position along the first column and the column segment connecting the first position to its nearest position along the second column is 90°. In a stacked grid, the distance between adjacent positions along the X axis is equal to the X distance 31, and the shortest distance between adjacent positions along the X axis is the Y distance 33.

[0085] The grid can be an offset grid as depicted in Figure 3. In an offset grid 49, the positions where 3D printing can be applied along the first X-axis are not directly above the positions along the second X-axis that are directly below the first X-axis. In other words, the angle 45 formed between the column segment connecting the first position along the first X-axis to an adjacent position along the first X-axis and the column segment connecting the first position to its nearest position along the second X-axis is greater than or less than 90°.

[0086] Just as positions within a two-dimensional grid containing two-dimensional layers (i.e., including both printed and voided areas) can be stacked or offset, subsequent overlaid grids can also include positions that are stacked or offset in the Z direction. Positions of adjacent upper layers are "stacked" if the angle between adjacent positions of the adjacent upper layers is approximately 90 degrees with respect to both the X and Y directions defined by either grid of the adjacent layers. Positions of adjacent upper layers are offset if the angle is not 90 degrees.

[0087] A layer offset configuration may be desirable, for example, when the printing spacing within a layer includes non-overlapping or non-contact printing within individual layer grids. For example, if printing within a given two-dimensional layer does not overlap or touch, these printings can be bridged by using a layer offset configuration, where printing in adjacent layers overlaps or touches multiple non-overlapping, non-contact printings.

[0088] Layers overlapping in the Z direction may be unevenly or evenly spaced along the Z direction. This spacing is the Z spacing. The 3D part may have periodicity in the Z direction, and the Z spacing between adjacent layers is similar among the layers above the 3D part. The Z spacing may be as small as a few nanometers or as large as a few millimeters, and may depend on the size of the 3D print and / or the stacking / offset nature of the 2D layer configuration. The Z distance is preferably about 2 nm to about 2 mm, more preferably about 1 μm to about 1 mm, more preferably about 10 μm to about 500 μm, and more preferably about 20 μm to about 200 μm.

[0089] Those skilled in the art will understand that the X and Y directions defining any two-dimensional layer can be chosen to some extent arbitrarily for a given pattern. For example, Figure 4B depicts an embodiment of "2" produced by laser 3D printing, where the X direction is perpendicular to the 3D printed "2" 61. Those skilled in the art will understand that the X direction can easily be the same as being horizontal to the 3D printed "2" 61.

[0090] Those skilled in the art will understand that any conventional laser printing process can be used in conjunction with a CV bitmap laser printing process. For example, a 3D part containing overlapping CV-bitmap printed layers may further include additional printing formed by a vector process. One example includes a 3D part in which the internal printing, including the part, is formed from the CV bitmap process of the present invention, and the contour or external portion of the 3D part may be formed by a vector process.

[0091] Those skilled in the art will understand that the grid (e.g., 39 and 49) and the regular spacing between adjacent positions assume a flat surface of the part. If the part surface is curved, the spacing may change with the curvature of the surface.

[0092] Figures 4A and 4B illustrate the difference between laser 3D printing via bitmap grid 3D printing using the CV bitmap process 4A of the present invention and a conventional vector 3D printing process 4B, where in both cases the alphanumeric characters 60 and 61 (i.e., the digit "2") are laser 3D printed. The alphanumeric character 60 has clean, sharp edges and is substantially better defined with very little stray 3D printing. Figure 4B is very contrasting, with mostly undefined edges and a considerable amount of stray 3D printing 62 outside the boundary of the alphanumeric character 61. Both characters 60 and 61 were 3D printed in approximately the same amount of time.

[0093] Improving laser 3D printing rates As discussed, the present invention enables laser 3D printing of parts at higher speed and with greater precision than conventional processes. Existing raster processes are very slow but relatively accurate, while vector laser 3D printing processes are faster and more accurate at low speeds but very coarse at high speeds, resulting in unclear 3D prints that are difficult for consumers or machines to read. Raster and vector are different graphic file types that require different modes of laser processing. The main differences between the modes required to laser process each type lie in the movement of the Garbo, or laser beam steering, and the parameters used.

[0094] The vector path, typically in the case of images, is slower because it requires the Garbo set to spend time accelerating to a user-defined maximum surface velocity (determined by multiplying the pulse interval by the repetition rate) and the length of the vector distance. A longer vector distance allows the vector raising device to reach its maximum surface velocity, while a shorter vector distance causes the raising device to constantly accelerate and decelerate, never reaching the maximum surface velocity, resulting in longer 3D printing cycle times.

[0095] Vector processes are also less accurate than CV bitmap processes at high speeds due to the acceleration / deceleration of the Garbo that steers the laser beam. Specifically, the position of each laser 3D print must be communicated from computer-driven software to the laser 3D printer, and such communication must be updated during the 3D printing of a given pattern, for example, as the laser beam traverses a given row. A typical update frequency for this communication is about 10 μs, and therefore a laser that outputs pulses with a repetition rate of 100 kHz allows for updates in communication for each individual position in the grid. This also applies to raster laser 3D printing processes, which may further include variations in pulse output for each pulse as a means of achieving grayscale (e.g., dithering). As the surface velocity of the laser beam across the surface of the part increases, repetition rates exceeding 100 kHz are required to achieve the desired X spacing in the row, and each update from the software must now communicate the positions of multiple laser 3D prints (or voids / non-3D prints). While the calculations can be performed almost instantaneously, in the extremely fast time domain of high-speed laser 3D printing, Garbo cannot respond so quickly, and the acceleration / deceleration profile of the vector process is thought to result in a considerable number of misplaced 3D prints within a given row for the constant surface velocity profile of the present invention.

[0096] Figure 4B illustrates the benefits of using a fast vector-based process when 3D printing text containing alphanumeric characters, as well as the misalignment of 3D prints within columns. This figure shows many columns that are misaligned with each other due to either starting the 3D prints too early or too late, which can result in jagged outlines of alphanumeric characters, an overall blurred appearance, and potentially illegible characters (for example, being unable to distinguish an "8" from a "0").

[0097] In contrast, the process and resulting patterns of the present invention can be produced by a constant surface velocity (CV) bitmap path. The CV bitmap laser 3D printing process allows for increased speed and increased precision because there are no start and stop points within the row; rather, there is a user-defined maximum surface velocity (again, the pulse interval multiplied by the repetition rate) that is constant while pulses are applied or 3D printing is being performed. Furthermore, the lathing device of the present invention can increase speed when not 3D printing over relatively long distances (with respect to the X distance). For example, if there is a distance of 2-3 mm (or more) between 3D prints in a row of 3D printing, the lathing device can accelerate without losing precision, or otherwise move the laser beam at a constant surface velocity while pulsing it. This is yet another reason why the 3D printing system of the present invention is faster and more accurate than conventional devices.

[0098] Smaller Garbo sets (e.g., including lower-mass mirrors) allow higher acceleration to reach this user-defined maximum surface velocity. These Garbos can be adjusted to higher acceleration values ​​that allow the mirrors to reach their desired angular velocity in a shorter time. Interestingly, these values ​​can be specifically adjusted for bitmap processing at higher values ​​than for vector processing. In addition, the vector laser software has a maximum 3D printing surface velocity limit set to ensure that the laser 3D prints are close to their desired requested positions. As the maximum surface velocity threshold increases, the laser pulses have more error with respect to their desired positions in vector processing. Note that in CV bitmap 3D printing mode, since the surface velocity (e.g., both the angular velocity of the mirrors and the surface velocity of the laser beam) is constant during the 3D printing process, the maximum surface velocity threshold can be significantly increased to achieve lower overall 3D printing cycle times versus vector while still keeping the pulses in place.

[0099] The angular velocity of the Garbo set is important for job cycle time because it directly relates to the surface velocity of the laser beam across the part. The surface velocity of the laser beam is set by the angular velocity of the Garbo / mirror pair and the focal length of the raising device. Surface velocity = Garbo angular velocity (rad / sec) * Focal length (mm)

[0100] The surface velocity when generating laser 3D printing within a given row is primarily controlled by the X-Garbo / mirror set. Job cycle time may depend more on the laser surface velocity in the X direction than in the Y direction, and the X-Garbo / mirror set may be more responsive than the Y-Garbo / mirror set. For example, the mirrors on the X-Garbo / mirror set can be smaller (i.e., lower mass, smaller mirror size, lower inertia, higher acceleration motor capability).

[0101] The surface velocity of the laser beam across the surface of a part in current CV bitmap processes is far faster than that achievable in currently available laser 3D printing processes such as raster 3D printing and vector 3D printing processes. Current processes typically exhibit surface velocities of 1-2 m / s or less. The CV bitmap process of the present invention provides surface velocities exceeding 8 m / s, and even 10 m / s, 15 m / s, 18 m / s, 22.5 m / s, 32.5 m / s, 45 m / s, 60 m / s or more, and even 90 m / s or more.

[0102] The sweep path of the laser beam across the surface of a part can also contribute to reducing cycle time. Conventional raster laser 3D printing processes sweep the laser beam across columns in either a right-to-left or left-to-right direction, also known as unidirectional, and then "jump" the laser beam back after 3D printing each column (like a typewriter's carriage return) to start the subsequent column. In this way, subsequent columns can be easily aligned (i.e., stacked) and the grid positions can be aligned based on this identical starting point. To eliminate the jump distance and reduce the time between each 3D printed column, current CV bitmap processes use a "bidirectional" process in which 3D printing can be performed alternately in both directions (i.e., 3D printing is performed from left to right for the first column and from right to left for subsequent columns).

[0103] To keep the pulses aligned, the lathing device can be programmed to incorporate a laser-on-adjust, which is a delay function for each alternating row to keep the pulses aligned. For example, at a 3D printing surface velocity of approximately 22.5 m / s, an 8-microsecond delay is used for alternating rows. A typical bitmap laser software setup allows for the selection of a single pulse interval or pitch that is common in both the X and Y directions. By producing different X and Y distances, similar contrast can be produced for both human-readable (e.g., text) and machine-readable (e.g., UPC, QR code) objects.

[0104] Laser-on-adjust is an element of the inverted shape of the laser beam sweep path. The inverted profile refers to the path followed by the Garbo set directing the laser beam while the laser beam is inverted between rows (i.e., inverted to 3D print one row from left to right, then inverted to 3D print the next row from right to left). The laser is typically off (i.e., not emitting pulses) during the inversion. Laser-on-adjust helps align 3D prints within adjacent rows. For example, if the grid is a stacked grid, laser-on-adjust ensures that 3D prints in adjacent rows remain stacked. If an offset grid is used, laser-on-adjust ensures that the grid remains offset, and that the amount of offset remains relatively constant. Laser-on-adjust can be determined experimentally and generally varies with the angular velocity of the Garbo set.

[0105] The inversion of the laser beam shape after completing a row can also contribute to reducing cycle time. As discussed earlier, the laser beam is steered by a Garbo set, and the Garbo set's ability to accelerate and decelerate is a known limitation on the speed and accuracy of laser 3D printing in other (e.g., vector) 3D printing processes. Current CV bitmap processes overcome these limitations. For example, current CV bitmap processes do not accelerate or decelerate the laser beam while the laser is emitting pulses (i.e., making a laser 3D print). Instead, the laser beam is accelerated / decelerated only when the laser is not 3D printing a part, for example, when the laser beam is skipping multiple voids (or an entire row), or when the laser beam is inverted at the end of a row before 3D printing the next row. The inversion shape can be symmetrical or asymmetrical. An asymmetric inversion profile may be preferable when the speed at which the laser beam sweeps across the surface of the part is high.

[0106] As mentioned earlier, the geometric shape of the 3D printing interval is a major contributor to the cycle time. As considered, widening the position within the grid (i.e., increasing the X and Y distances) can result in a reduction in cycle time. Within a row, the X distance contributes to the cycle time in that the laser surface velocity is determined by the laser repetition rate and the X distance. Increasing the Y distance improves the cycle time by reducing the number of inversions that the Garbo set must perform (i.e., the number of rows with a given feature), which can account for up to 30-70% of the total cycle time at high speed. For example, to obtain similar-looking images within the reduced overall cycle time, the X distance can be made smaller and the Y distance larger. It has further been found that increasing the Y distance while simultaneously decreasing the X distance provides faster cycle times and improved readability of the 3D printed features.

[0107] The choice of orientation for 3D printing can also affect job cycle time at very high surface velocities. At very high surface velocities, reversal time can increase to a point where it dominates job cycle time. By selecting the 3D printing orientation to be approximately parallel to the longer dimension of the feature, reversal can be minimized, thereby reducing job cycle time. As mentioned above, the X and Y distances may be different, and this difference can contribute to shortening the job cycle, while any loss of strength or increase in porosity of the 3D part can be compensated for by reducing the spacing in either of the other directions.

[0108] In the laser 3D printing process of the present invention, the laser source is stationary, and the laser beam is guided by a lathing device including a series of lenses and mirrors controlled by an algorithm. The algorithm can read a digital image of a desired 3D printing pattern (for example, from a PDF file of the desired image) and replace that image with the 3D printing pattern on the target.

[0109] Microscopy Numerous parts were 3D printed according to the process of the present invention, and comparison parts were 3D printed using existing processes. The results of these comparisons are shown in Tables 1, 2, and 3, and Figure 5. To obtain these comparison data, samples were cut from laser 3D printed HDPE blow-molded bottles containing TiO2 using a utility knife and scissors. If the cut samples were not suitably flat, the samples were flattened on a microscope stage using tape or a frame. Stereoscopic microscopes such as a motorized Zeiss SteREO Discovery V20 (Carl Zeiss Microscopy, LLC, Thornwood, NY) equipped with a color camera such as an Axiocam 305 (5-megapixel CMOS, Carl Zeiss Microscopy, LLC, Thornwood, NY) were used to image the target letters, numbers, and images of the samples using reflected light illumination achieved with an LED ring light and light source such as a cold-light source CL 6000 LED lamp (Carl Zeiss Microscopy, LLC, Thornwood, NY). Typical light intensities of 80-100% of the maximum light intensity are used. Individual laser 3D prints, combined to form the target characters, numbers, or images, are resolved using a suitable magnification, combined with a zoom magnification such as 10x to 345x, using an objective lens such as an Achromat S 1.5x FWD 28mm (Carl Zeiss Microscopy, LLC, Thornwood, NY). For example, for characters, numbers, or images with a font size of 10pt, the total magnification is approximately 40x. After the target character enters the camera's field of view, the character, number, or image is focused using manual skill or, preferably, using an autofocus module via a user interface platform (such as Zen V2.6 Blue Edition or higher with Zen Autofocus module, Carl Zeiss Microscopy, LLC, Thornwood, NY).Before collecting images of letters, numbers, or pictures, the imaging settings are optimized by using the automatic exposure option from the user interface platform along with the lamp intensity. Images are collected in the highest possible resolution format, such as ZVI, and then exported as TIFF files with a resolution of approximately 2464 x 2056 pixels. Furthermore, the 3D printed columns of letters, numbers, or artwork should be approximately parallel to the horizontal boundaries of the image. If necessary, multiple images taken at higher magnifications can be precisely stitched together to encompass the entire area of ​​the letters, numbers, or image.

[0110] Image analysis Images from the microscope appear gray, but are captured in color. The images are converted to grayscale using the NTSC protocol. Suitable image analysis software is required to perform this step and several other image processing steps. Analysis functions implemented in MATLAB, available from The Mathworks, Inc. (Natick, MA), are referenced in this description of the method.

[0111] Microscopy and subsequent image analysis may be performed on one or more predetermined patterns, portions of predetermined patterns, or individual images within a predetermined pattern, such as graphics or alphanumeric characters. If image analysis is performed on a portion of a predetermined pattern, that portion (such as individual graphics or alphanumeric characters) must be isolated from any surrounding images, characters, or artwork before analysis. A mask may be drawn around the character or image in the predetermined pattern. The mask isolates the character or image from other partial characters, numbers, barcodes, artwork, smudges, or other defects that may occur in the image.

[0112] Image analysis first relies on identifying the laser 3D print containing the image. Laser 3D prints can be identified by any reasonable means, for example, by repeatedly thresholding a grayscale image from a microscope. The starting threshold is set to capture only a few pixels that fall within some of the 3D print. The threshold then gradually changes to capture an ever-increasing area of ​​the 3D print. Progressive thresholding continues from the starting threshold to the stopping threshold. The stopping threshold can be determined automatically, for example, by using MATLAB's "multithresh" function (i.e., Otsu's binarization method). Progressive thresholding can be advantageous in analysis because areas of the 3D print may overlap and / or merge, and the background may not be perfectly uniform. The direction of threshold progression (i.e., light to dark, or dark to light) can be used to identify dark 3D prints against a relatively light background, or bright 3D prints against a relatively dark background. In the presented embodiment, dark 3D prints against a relatively light background are identified.

[0113] Next, when the area reaches a certain size, the connected components can be used to identify individual 3D prints. The connected component algorithm is run with each new threshold to group contact pixels into blobs. When a blob reaches 50% of the area of ​​a 3D print, it is identified as a 3D print. The center coordinates of the 3D print are found using the centroid method, which is implemented in MATLAB's "regionprops" function. The center is then used to determine the distance between adjacent 3D prints in a column (e.g., X distance) and the distance between adjacent columns of 3D prints (e.g., Y distance) (see below).

[0114] Determine the observed X-distance, Y-distance, and standard deviation. Exemplary means for determining the X and Y distances, and their standard deviations, can also be performed using image analysis, but those skilled in the art will understand that any means for determining these distances and standard deviations can be used. One means for determining these values ​​by image analysis involves the use of “Delaunay triangles.” In the Delaunay triangle method, the center coordinates of the 3D print are passed to MATLAB’s “Delaunay Triangulation” function, which creates a triangulation based on the center point. The edges of the Delaunay triangulation never intersect, and the center points are connected in a nearest-neighbor style.

[0115] The X-distance is taken as the distance between adjacent 3D printed positions along a given column in a grid. Adjacent 3D printed positions along a given column result in horizontal edges in a Delaunay triangulation data structure. These horizontal edges can be separated from other edges in the triangulation by calculating the angle of the edges. Horizontal edges in a column of the grid are within + / - 10 degrees of the horizontal edges of the image. Since the grid consists of periodic intervals of positions along the columns, the X-intervals should be relatively consistent (e.g., have a low standard deviation). In this analysis, horizontal edges with a length greater than twice the programmed distance can be excluded from consideration as indicating non-adjacent positions. The observed X-distance determined when analyzing an image such as alphanumeric characters is then taken as the average length of the horizontal edges between adjacent 3D prints for all 3D prints / columns in a given image or character. The X-distance for multiple characters in a macroscopic image can then be further averaged to provide the average X-distance for a given 3D printing condition and a given image or given pattern. Table 1 depicts the observed X-distances for characters / numbers associated with UPC codes described for a series of 3D printing conditions.

[0116] The Y-distance can be determined as the vertical distance between adjacent columns. In Delaunay triangulation, a horizontal edge can be part of two adjacent triangles. Each base edge gives each triangle two vertices, and the third vertex is the nearest neighbor 3D print in either the adjacent column above or below the base edge.

[0117] For each base edge, the vertical distance to the nearest 3D print above and below the base edge is determined. Only the minimum of these two distances (i.e., the closest) is recorded. Using only the minimum distance helps ensure that columns are adjacent and prevents double counting of columns. The mean and standard deviation of these vertical distances across a given image are then taken as the mean Y distance and standard deviation of the image. The top and bottom columns of letters / numbers are not used as the base of the measured triangle because they have only one adjacent column. The Y distances of multiple images in a given pattern or portion thereof can then be further averaged to provide the mean Y distance and standard deviation of a given pattern or portion thereof (e.g., a given alphanumeric string).

[0118] As shown in Figure 4B, high-speed vector laser 3D printing processes can result in substantial displacement or overhang of 3D prints or voids within a row, leading to blurry images (such as alphanumeric characters) with jagged contours. The laser 3D printing process and the parts 3D printed by this invention do not produce such substantial displacement and blurring. Displacement within a row can be represented using any of a number of means, including simple visual inspection. For example, such means may include simply observing a character (or other element of a given pattern) and evaluating whether it is legible given prior knowledge of the intended 3D printed pattern (e.g., alphanumeric characters). Displacement can also be quantified. Importantly, human and machine-readable patterns generally include a "smooth" contour (as opposed to the jagged contour shown in Figure 6B). In other words, for user-readable and machine-readable patterns, the leftmost and rightmost 3D-printed positions within a given column or 3D-printed portion of a column generally do not substantially displace (in the X direction) with respect to the X distance from the leftmost and rightmost 3D-printed positions (each) within the adjacent columns (above and below). This displacement of 3D-printed positions results in blurry and indistinct patterns, producing larger patterns / characters than intended, and reducing both user and machine readability.

[0119] In quantifying displacement, the starting point of each 3D printed portion within a given column of letter or pattern elements is considered the leftmost 3D print, and the ending point of each 3D printed portion within the column is considered the rightmost 3D print. The starting and ending points for each 3D printed portion within a column are determined relative to the corresponding starting and ending points (each) of the adjacent columns above and below it. A column under consideration is determined to be "displaced" to the left of the letter / pattern element if the starting points of both the column above and below it are to the left of the starting point of the measured column, and a column under consideration is determined to be "displaced" to the right if the ending points of both the column above and below it are to the right of the ending point of the measured column. The horizontal distance from the starting (and ending) point of the column to the starting (and ending) points of the columns above and below is determined, and the displacement is taken as the shorter of these two distances. Leftward displacement is the displacement determined by the starting point, and rightward displacement is the displacement determined by the ending point. The 3D printed portion within each column may contain no displacement, or may contain left-side or right-side displacement, or both left-side and right-side displacement. The top and bottom columns containing the images being analyzed (i.e., alphanumeric characters) are omitted from the analysis because they do not have two adjacent columns. One means of identifying the start and end points of each column is to use the Delaunay triangulation analysis discussed earlier to determine the X-distance, Y-distance, and standard deviation.

[0120] The "% displacement" for a given image, such as alphanumeric characters, is the sum of the displacements for the columns containing the characters, divided by the number of columns that make up the characters. % displacement = (total displacement within the character) / (number of columns within the character) * 100

[0121] For a given pattern containing multiple alphanumeric characters as text, the "A%D" or average % displacement is simply the sum of the % displacements for each character in the sample set divided by the number of characters in the sample, "n".

[0122] Another way to quantify the precision of the high-speed laser 3D printing of the present invention is by the percentage of misprinted locations, i.e., "mismarked %". Referring here to Figure 7, which shows the alphanumeric character "2" 3D printed with a grid pattern according to the present invention. There are approximately 130 3D printed locations 54. In Figure 7, there are 8 voids 101 that should be 3D printed locations. Furthermore, there are 4 3D printed locations 100 that should be voids. As should be obvious, both the voids that should be 3D printed locations and the 3D printed locations that should be voids are misprinted 3D prints, and therefore they are added together and compared to the number of 3D printed locations. In the example of Figure 7, there are 12 (8+4) mistakes out of a total of 130 desired 3D printed locations. Mismarked % = number of mistakes divided by the number of desired 3D printed locations and multiplied by 100, ((12 / 130) * 100) = 9.23%. Figure 4B shows a significantly misprinted alphanumeric character ("2") where the mismarked percentage exceeds 20%.

[0123] The "average % mismarked" for a given pattern containing multiple alphanumeric characters as text is simply calculated by dividing the sum of the mismarked percentages for each alphanumeric character by the number of alphanumeric characters. To achieve the desired readability of the alphanumeric text, the average % mismarked for alphanumeric characters is less than about 20%, preferably less than about 15%, more preferably less than about 10%, and even more preferably less than about 5%. The following criteria are used to calculate the average for both the calculation of the % precision and the provision of the standard deviation.

[0124] Samples and data Table 1 shows data obtained by laser 3D printing the same pattern onto four different parts and then analyzing them using the method described above. In this case, the 3D printing was of the industry standard UPC code. Those skilled in the art will understand that, in order for a UPC scanner to read the code quickly and accurately, the UPC, which must be displayed on all goods purchased by a consumer, must have black bars and alphanumeric characters that are clearly defined against a brighter, preferably white, background. In other words, the UPC code must be printed or 3D printed with precision so that it can be accurately read by a scanner or a person. As an example, Figure 7 shows a UPC code 70 laser 3D printed according to the process of the present invention. The UPC code 70 is a mixture of bars 72 of varying widths and alphanumeric characters 74.

[0125] Prior to this invention, vector laser 3D printing was the fastest laser 3D printing system available, but Table 1 clearly shows that as the speed of vector 3D printing increases, the precision of the 3D printing substantially decreases. More specifically, vector 3D printing was tested at maximum Garbo angular velocities of 15.6, 350, and 1000 radians / second and compared to the CV bitmap 3D printing of this invention at a maximum surface velocity of 1000 radians / second. The target Y distance is provided in the first column, where the actual Y distance for each of the n samples was measured (in mm) and then averaged. More importantly, the sigma σ, standard deviation, was calculated for the n samples using the standard formula. The standard deviation is a measure of how far each individual sample deviated from the target Y distance. For example, if only two samples were run at a target Y distance of 0.150, and one sample was 0.200 and the other was 0.100, their average would be exactly 0.150, the target value. However, precision is unavoidable. The standard deviation in this example is a large number indicating a lack of precision for these two hypothetical samples, whose mean appears to be as intended.

[0126] Comparing vector 3D printing at a Garbo angular velocity of 15.6 radians / second (first entry in Table 1) with CV bitmap 3D printing at 1000 radians / second (last entry in Table 1), the average X-distance, average Y-distance, and corresponding standard deviations are similar across the four target X-distances and Y-distances tested. As the Garbo angular velocity of vector 3D printing increases to 1000 radians / second, the average X-distance and corresponding standard deviation remain reasonable, but the Y-distance standard deviation becomes unacceptable, and the UPC code becomes ultimately unreadable for both barcode readers and humans reading the underlying digits. For UPC codes 3D printed by the process of the present invention, both the average X-distance and standard deviation, and the average Y-distance and standard deviation are very good, even at the maximum Garbo angular velocity of 1000 radians / second. Thus, the CV bitmap laser 3D printing of the present invention offers a clear advantage in speed and precision over prior vector 3D printing systems.

[0127]

number

[0128] When determining the average percentage displacement or mismarked average percentage across a series of alphanumeric characters such as text, the sample size must contain at least six distinct alphanumeric characters selected from the group consisting of S, s, R, r, T, t, N, n, A, a, E, e, O, o, U, u, 1, 2, 3, 4, 5, 6, 7, 8, and 9, and the sample size should be no more than 10 alphanumeric characters. Furthermore, the alphanumeric characters should be within the font size range of 6pt to 16pt (height approximately 2.1mm to 5.64mm).

[0129]

Table 1

[0130] Table 2 is another set of comparison data laser 3D printed with the precision at which the UPC code is legible. That is, at each speed and each target Y distance and X distance, the time required to produce a machine-readable UPC was measured. As clearly shown, as Velocity Max continuously increases, the time required to laser 3D print the UPC code in an accurate / readable manner was actually longer for the vector 3D printing process.

[0131]

Table 2

[0132] Table 3 includes data obtained from the laser 3D printed sample shown in Figure 5. The top column of Table 3 shows which of the five samples the data corresponds to in Figure 5 (81 - 85), how each sample was laser 3D printed, and how it compares to the other samples. Figure 5 shows a 5 mm square 88, sample text 87 (alphanumeric "Abg123"), and a series of 1 mm x 5 mm rectangles 86 spaced 1 mm apart. The repetition rate is 700,000 rad / s 2The normal acceleration used is 500 kHz. The second row of Table 3 shows how each sample was 3D printed, the third row is the maximum Garbo angular velocity of the laser 3D print, and the fourth and fifth rows are a qualitative description of the results. Actual data for 3D printing 5 mm squares 88, text 87, and a standardized rectangle of 1 mm × 5 mm 86 are shown in the remaining rows of Table 3. In this case as well, it is very clear that the speed and precision of laser 3D printing with CV bitmaps of the present invention are far superior to conventional vector 3D printing systems. An f-theta lens with a focal length of 250 mm was used.

[0133] [Table 3]

[0134] Standardized rectangle method The standardized rectangle method is a standardized test for measuring both the speed and accuracy of any raising device. Simply put, it can test any raising device that can be programmed to print 20 identical rectangles (similar to a simplified UPC code). While the test details are provided below, those skilled in the art will understand that the time required to print the standardized rectangles is crucial to demonstrating the advantages of the present invention. The last two rows of Table 3 show examples of the time required to print standardized rectangles using four raising devices / processes available today and one raising device / process according to the present invention. Prior raising devices / processes required 1.5–1.0 seconds to print standardized rectangles. The raising device / process according to the present invention required only 0.185 seconds, which was 500–800% faster than the prior devices.

[0135] As shown in Figure 5, the standardized rectangle 86 is a series of 20 identical rectangles 91 in Figure 9, which are approximately 1 mm wide 95 × approximately 5 mm high 93 and spaced about 1 mm apart. The width 95 of the rectangles must be in the range of 0.94 mm to 1.22 mm. The height 93 of the rectangles must be in the range of 4.8 mm to 5.00 mm. Each rectangle contains 80 to 84 parallel columns 97. Each column extends in the X direction 92, i.e., 1 mm wide 98. Thus, the Y distance 96, which is the distance between columns, is in the range of 0.24 mm to 0.26 mm. Each column 97 contains 20 to 24 3D prints 99. For clarity, it is obvious that not all 3D prints 99 are shown.

[0136] Unless otherwise specified, all percentages are weight percentages based on the weight of the composition. Unless otherwise specifically stated, all ratios are weight ratios. All numerical ranges include narrower ranges, and the upper and lower range limits are interchangeable in creating further ranges that are not explicitly defined. The number of significant figures does not limit the quantity indicated, nor does it limit the precision of the measurement. All measurements are understood to be taken at approximately 25°C and under ambient conditions, where “ambient conditions” means conditions at approximately 1 atmosphere and approximately 50% relative humidity.

[0137] The dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​listed. Instead, unless otherwise specified, each such dimension is intended to mean both the listed value and the functionally equivalent range encompassing that value. For example, a dimension disclosed as "40 mm" is intended to mean "approximately 40 mm."

[0138] All documents referenced herein, including any patents or patent applications that are cross-referenced or related, and any patent applications or patents for which this application claims priority or benefit thereof, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. No reference to any document shall be deemed prior art to any invention disclosed or claimed herein, nor shall any such invention be taught, suggested, or disclosed, either alone or in combination with any one or more other references. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to that term in this document shall prevail.

[0139] While specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications within the scope of the invention be covered in the appended claims.

Claims

1. A 3D part printed by a pulse-raising device, Each layer consists of a series of overlapping layers, including multiple 3D prints. The pulses from the pulse-raising device form the 3D print, and the absence of pulses forms voids. A 3D component wherein the pulse-raising device is controlled by a computing device that transmits instruction packets to the pulse-raising device, and the instruction packets include at least two individual instructions, each of which indicates whether to pulse-drive or not pulse-drive the laser.

2. The overlapping layers include a 3D printed grid pattern and voids, the grid pattern includes a plurality of positions arranged along a series of substantially parallel columns, each position including either one 3D printed or one void. The pulses from the pulse-raising device form the 3D print, and the absence of pulses forms the void. The 3D component according to claim 1, wherein each individual instruction notifies the laser whether to pulse-drive or not, and each of these instructions generates a 3D print or void at each position on the grid pattern.

3. The component according to claim 2, wherein the position between adjacent parallel rows is offset.

4. The component according to claim 2 or 3, wherein the position in the two-dimensional layer is offset in the Z direction.

5. A method for 3D printing parts using a pulse-raising device, A step of defining a series of overlapping layers including multiple 3D prints and voids of a grid pattern, wherein the grid pattern includes a plurality of positions arranged along a series of substantially parallel columns, each position including either one 3D print or one void; The steps include forming the 3D print by pulse-driving the pulse-raising device and generating voids by not pulse-driving the pulse-raising device, A method comprising the steps of controlling a pulse-raising device by a computing device that transmits a packet of instructions to the pulse-raising device, wherein the packet of instructions comprises at least two individual instructions, and each individual instruction notifies the pulse-raising device whether to pulse-drive or not, thereby generating 3D prints or voids at each position on the grid pattern, respectively.

6. The method according to claim 5, wherein at least one of the rows is 3D printed by two different packets.

7. The method according to claim 5, wherein the instruction packet further comprises two or fewer, preferably only one, individual instructions relating to the position of a location within the grid pattern.

8. A part 3D printed by a pulsed laser containing a predetermined grid pattern The grid pattern includes a plurality of positions positioned in two or more columns, the two or more columns being substantially parallel, each adjacent pair of positions along any one of the two or more columns being separated by an X distance, and each adjacent pair in the two or more columns being separated by a Y distance. The pulsed laser beam moves across the row at a constant surface velocity of about 8 m / s, preferably 14 m / s, more preferably 18 m / s, and even more preferably 22 m / s, when a continuous 3D print is formed. A component in which the Y-distance standard deviation is less than about 0.040, preferably less than about 0.034, preferably less than about 0.028, more preferably less than about 0.010, and even more preferably less than about 0.

005.

9. The component according to claim 8, wherein the beam of the pulsed laser moves in a bidirectional profile such that the laser beam moves along a first column in a first direction and a second column in a second direction.

10. The component according to claim 8, wherein the pulsed laser beam is directed by two garbosets, each comprising a mirror and a galvanometer, and the angular velocity of rotation of at least one garboset is greater than about 40 rad / second, preferably 56 rad / second, more preferably 72 rad / second, and even more preferably 90 rad / second.

11. The component according to claim 8, wherein the beam of the pulsed laser has a repetition rate exceeding approximately 100 kHz.

12. A pulsed laser-printed part comprising a series of superimposed 3D printed layers, each having a predetermined grid pattern, The grid pattern includes a plurality of positions positioned in two or more columns, the two or more columns being substantially parallel, each adjacent pair of positions along any one of the two or more columns being separated by an X distance, and each adjacent pair in the two or more columns being separated by a Y distance. The pulsed laser beam moves across the row at a constant surface velocity of about 8 m / s, preferably 14 m / s, more preferably 18 m / s, and even more preferably 22 m / s, when a continuous mark is formed. A component having a grid pattern with an average percentage displacement of less than about 150%, preferably less than about 120%, preferably less than about 100%, more preferably less than about 70%, and even more preferably less than about 50%.

13. The component according to claim 12, wherein the pulsed laser beam is directed by two garbosets, each comprising a mirror and a galvanometer, and the angular velocity of rotation of at least one garboset is greater than about 40 rad / second, preferably 56 rad / second, more preferably 72 rad / second, and even more preferably 90 rad / second.

14. A pulsed laser-printed part comprising a series of superimposed 3D printed layers, each containing a predetermined pattern at a location including a 3D printed grid pattern or voids, The grid pattern includes a plurality of positions positioned in two or more columns, the two or more columns being substantially parallel, each adjacent pair of positions along any one of the two or more columns being separated by an X distance, and each adjacent pair in the two or more columns being separated by a Y distance. The pulsed laser beam moves across the row at a constant surface velocity during pulse driving, exceeding approximately 8 m / s, preferably 14 m / s, more preferably 18 m / s, and even more preferably 22 m / s, when a continuous 3D print is formed. A component in which the average percentage of mismarked parts is less than about 20%, preferably less than about 15%, more preferably less than about 10%, and even more preferably less than about 5%.

15. A part having a surface 3D printed by a pulsed laser, comprising a first predetermined pattern at each position containing a 3D printed grid pattern or voids, and a second predetermined pattern at each position containing a 3D printed grid pattern or voids, The first grid pattern and the second grid pattern include a plurality of positions positioned in two or more columns, the two or more columns being substantially parallel, each adjacent pair of positions in the plurality of positions along any one of the two or more columns being separated by an X distance, and each adjacent pair in the two or more columns being separated by a Y distance. The first grid pattern and the second grid pattern differ in at least one of the X distance and the Y distance. A component having a pulsed laser beam that moves across the row at a constant surface velocity during pulse driving of about 8 m / s, preferably 14 m / s, more preferably 18 m / s, and even more preferably 22 m / s, when a continuous 3D print is formed.

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