Photonic fusion printers print objects via additive printing processes. Photonic fusion printers direct energy (e.g., light) output by an energy source (e.g., a lamp) to melt, fuse and solidify together particles of a powder bed to form objects having different shapes. Three-dimensional (3D) objects are formed by additive application of successive layers or volumes of a build material, such as a powder or powder-like material, to an existing solid portion, solid surface or solid previous layer.
When beneficial, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. The figures are not to scale. Instead, for clarity, dimensions may be enlarged in the drawings. Connecting lines or connectors shown in the various figures presented are intended to represent example functional relationships and/or physical or logical couplings between the various elements.
Micro-mirror arrays (e.g., an array of micro-mirrors) have the potential to enable high-speed three-dimensional (3D) photonic fusion printing that has lower consumable costs, greater green strength (e.g., handling strength), fewer solidification cracks, etc. However, some micro-mirror arrays can withstand up to approximately fifty watts per square centimeter (50 W/cm2) of continuous energy exposure. Beyond this level, micro-mirrors can become damaged, e.g., begin melting. An example flash lamp used in photonic fusion provides approximately fifty Joules per square centimeter (50 J/cm2) per each layer. However, a peak intensity of approximately ten kilowatts per square centimeter (10 kW/cm2) at a bed of powder (a.k.a. powder bed) may be desired, which is well beyond the 50 W/cm2 constant intensity (or 1 kW/cm2 pulsed intensity for a certain pulse duty cycles and pulse width) tolerated by micro-mirrors. Thus, in some examples, the energy intensity for photonic fusion would damage some micro-mirrors.
It has been advantageously discovered that typically (e.g., on average) about ten percent (10%) or so of a powder bed (e.g., 10% of the fusing areas of the powder bed) will be fused per layer. The remaining ninety percent (90%) or so are not fused during that time period. In prior systems, there is a one-to-one (1:1) correspondence between micro-mirrors and fusing areas, and a micro-mirror is either reflecting energy towards its respective fusing area, or not (e.g., reflecting energy into an energy sink). Thus, in an example, roughly 90% of the micro-mirrors are unused during any given time period and their associated energy (e.g., light) is wasted. In some examples, the fusing areas to be fused are used to concurrently print multiple objects at the same time. For example, one-half of the fusing areas could be allocated to a first object, and the other half of the fusing areas could be allocated to a second object.
In stark contrast, example apparatus and methods disclosed herein advantageously use the previously unused 90% or so of the micro-mirrors to irradiate the 10% or so of the fusing areas that are being fused, thereby delivering additional energy to the 10% or so of the fusing areas that are being fused. Disclosed example micro-mirror arrays allow dynamic control of micro-mirror orientations. Each micro-mirror can be separately oriented (e.g., angled) to direct energy toward any fusing area at any given time. The micro-mirror orientations can be changed for any time period, layer, etc. More than one micro-mirror can be oriented to the same fusing area for the same or different time period. By dynamically controlling micro-mirror angles, one hundred percent (100%) of the micro-mirrors can be used to irradiate (e.g., direct light onto) the 10% of so of the powder bed being fused. Therefore, the intensity of the light at the fusing areas of the powder bed being fused can be increased by a factor of ten (1:10) compared to the intensity of light at the micro-mirrors. For example, using a 50 W/cm2 continuous intensity (or 1 kW/cm2 pulsed intensity) light source and ten micro-mirrors, a pulsed intensity of light at the powder bed of 10 kW/cm2 can be achieved, without risk of micro-mirror damage. Alternatively, for a given intensity of light needed at the powder bed, the intensity of light that the micro-mirrors need to handle is reduced by a factor of ten (10:1). Thus, the benefits of flooded light photonic fusion can be obtained for micro-mirror based printers without risk of micro-mirror damage. Additionally, and/or alternatively, each layer can be fused with N exposures by fusing 10%/N of the fusing area at each exposure.
Reference will now be made in detail to non-limiting examples, some of which are illustrated in the accompanying drawings.
To direct energy (e.g., visible light, infrared radiation, heat, etc.) emitted by an energy source 106 onto the powder bed 104, the example printer 100 of
In some examples, the micro-mirror array 108 is part of a microelectromechanical system (MEMS) device. In some examples, orientations, angles, positions, states, etc. of the micro-mirrors 110, 112 are controlled through application of voltage(s) between electrode(s) around the micro-mirrors 110, 112. In some examples, the micro-mirrors 110, 112 may have micron-scale sizes, e.g., between around ten microns and around twenty microns. In some examples, micro-mirrors 110, 112 are formed from any of a variety of materials, such as, for example. aluminum with a protective silicon dioxide layer on the aluminum to protect the aluminum from heat.
Returning to
To control the example micro-mirror array 108, the example printer 100 of
To determine to which fusing area 114 a micro-mirror 110, 112 is to be oriented, if any, the example printer 100 includes the example imaging system controller 118. The example imaging system controller 118 receives from an example printer controller 120 a list of fusing areas 114 to be fused during a time period, for a layer of an object being printed, etc. In some examples, the imaging system controller 118 evenly allocates micro-mirrors 110, 112 among the fusing areas 114 to be fused, and allocates the micro-mirrors 110, 112 closest to each fusing area 114 being fused to that fusing area 114. Other allocations may be used.
The imaging system controller 118 determines the angle(s) between each micro-mirror 110, 112 and the fusing area 114 to which the micro-mirror 110, 112 is assigned. Based on the angle, the imaging system controller 118 determines the needed orientation of the micro-mirror 110, 112. The controls (e.g., voltages) needed to set the micro-mirror 110, 112 to that orientation are determined and sent to the micro-mirror array 108.
In the illustrated example of
Returning to
Dynamically controllable micro-mirror arrays can be used to provide alternative and/or additional advantages for photonic fusion printers, such as the example printer 100 of
Turning to the side view of
While an example manner of implementing the printer 100 is illustrated in
A flowchart representative of example hardware logic, machine-readable instructions, hardware implemented state machines, and/or any combination thereof for implementing the printer 100 of
As mentioned above, the example processes of FIG.7 may be implemented using executable instructions (e.g., computer and/or machine-readable instructions) stored on a non-transitory computer and/or machine-readable medium such as a hard disk drive, a flash memory, a read-only memory, a CD-ROM, a DVD, a cache, a random-access memory and/or any other storage device or storage disk in which information is stored for any duration (e.g., for extended time periods, permanently, for brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term non-transitory computer-readable medium is expressly defined to include any type of computer-readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media.
“Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.
The program of
The imaging system controller 118 determines the angles to be controlled for the micro-mirrors 110, 112 based on the allocations (block 708), and the mirror controller 116 correspondingly controls the orientation of the micro-mirrors 110, 112 (block 710).
The imaging system controller 118 activates the energy source 106 (block 712), and the energy is directed to the micro-mirrors 110, 112 and reflected to the desired fusing area 114 on the powder bed 104 to print the 3D object. Control returns to block 704 to print the next layer. When all layers have been printed (block 714), control exits from the example program of
The processor platform 800 of the illustrated example includes a processor 810. The processor 810 of the illustrated example is hardware. For example, the processor 810 can be implemented by integrated circuit(s), logic circuit(s), microprocessor(s), GPU(s), DSP(s), or controller(s) from any desired family or manufacturer. The hardware processor may be a semiconductor based (e.g., silicon based) device. In this example, the processor 810 implements the example mirror controller 116, the example imaging system controller 118 and the example printer controller 120.
The processor 810 of the illustrated example includes a local memory 812 (e.g., a cache). The processor 810 of the illustrated example is in communication with a main memory including a volatile memory 814 and a non-volatile memory 816 via a bus 818. The volatile memory 814 may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS® Dynamic Random Access Memory (RDRAM®) and/or any other type of random access memory device. The non-volatile memory 816 may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory 814, 816 is controlled by a memory controller.
The processor platform 800 of the illustrated example also includes an interface circuit 820. The interface circuit 820 may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), a Bluetooth® interface, a near field communication (NFC) interface, and/or a PCI express interface.
In the illustrated example, input device(s) 822 are connected to the interface circuit 820. The input device(s) 822 permit(s) a user to enter data and/or commands into the processor 810. The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system.
Output device(s) 824 are also connected to the interface circuit 820 of the illustrated example. The output devices 824 can be implemented, for example, by the micro-mirror arrays 108, 420, 502, 604, 606, display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube display (CRT), an in-place switching (IPS) display, a touchscreen, etc.), a tactile output device, a printer and/or speaker. The interface circuit 820 of the illustrated example, thus, typically includes a graphics driver card, a graphics driver chip and/or a graphics driver processor.
The interface circuit 820 of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem, a residential gateway, a wireless access point, and/or a network interface to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network 826. The communication can be via, for example, an Ethernet connection, a digital subscriber line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a line-of-site wireless system, a cellular telephone system, etc.
The processor platform 800 of the illustrated example also includes mass storage device(s) 828 for storing machine readable instructions such as software and/or data. Examples of such mass storage devices 828 include floppy disk drives, hard drive disks, CD drives, Blu-ray disk drives, redundant array of independent disks (RAID) systems, and DVD drives.
Coded instructions 832 including the coded instructions of
Example methods, apparatus and articles of manufacture have been disclosed that improve the performance of printers, such as photonic fusion printers. The disclosed example methods, apparatus and articles of manufacture enhance the operations of a printer by improving the light handling of the printer. That is, through the use of these processes and structures, printers can operate more efficiently by providing more light to fuse powder without requiring a light source with higher light intensity, or risking exposure of printer components to high light intensities. The disclosed methods, apparatus and articles of manufacture are accordingly directed to advancements in the functioning of a printer.
Example methods, apparatus, and articles of manufacture to improve the light usage efficiency of photonic fusion printers are disclosed herein. Further examples and combinations thereof include at least the following.
An example printer includes a first micro-mirror, a second micro-mirror, a third micro-mirror, an energy source; and a controller. The controller is to, during a first time period, orient the first micro-mirror toward a first area of a powder bed, orient the second micro-mirror toward the first area of the powder bed, orient the third micro-mirror toward a second area of the powder bed, and activate the energy source, wherein powder in the first area of the powder bed fuses to form a portion of an object in response to energy directed by the first micro-mirror toward the first area and in response to concurrent direction of energy by the second micro-mirror toward the first area.
In some examples, the controller is to determine an angle between the first micro-mirror and the first area, and control an orientation of the first micro-mirror based on the angle.
In some examples, powder in the second area of the powder bed fuses to form another portion of at least one of the object or another object in response to concurrent direction of energy by the third micro-mirror toward the second area.
In some examples, the controller is to, during a second time period, orient the first micro-mirror toward a third area of the powder bed, orient the second micro-mirror toward the third area of the powder bed, and activate the energy source, wherein powder in the third area of the powder bed fuses to form another portion of the object in response to energy directed by the first micro-mirror toward the third area and in response to concurrent direction of energy by the second micro-mirror toward the third area.
In some examples, the controller is to, during a second time period, orient the first micro-mirror toward a third area of the powder bed, orient the third micro-mirror toward the third area of the powder bed, and activate the energy source, wherein powder in the third area of the powder bed fuses to form another portion of the object in response to energy directed by the first micro-mirror toward the third area and in response to concurrent direction of energy by the third micro-mirror toward the third area.
Some examples include a micro-mirror array including the first micro-mirror, the second micro-mirror, and the third micro-mirror.
In some examples, the energy source includes at least one of a source of pulsed visible light, a source of pulse infrared energy, a source of pulsed heat, a source of continuous visible light, a source of continuous infrared energy, or a source of continuous heat.
An example printer includes an energy source, an array of micro-mirrors, and a controller to control first micro-mirrors of the array of micro-mirrors to concurrently direct energy from the energy source toward a first fusing area in a powder bed to add first material to a solid portion of an item.
In some examples, the controller is to control second micro-mirrors of the array of micro-mirrors to concurrently direct energy from the energy source toward a second fusing area in the powder bed to add second material to the solid portion of the item.
In some examples, the first micro-mirrors include the second micro-mirrors, and the second fusing area is different from the first fusing area.
In some examples, the number of micro-mirrors in the array of micro-mirrors is less than a number of fusing areas in the powder bed.
In some examples, the controller is to, determine angles between the first micro-mirrors and the first fusing area, and control orientations of the first micro-mirrors based on respective ones of the angles.
In some examples, at least one of a first distance from the energy source to the array of micro-mirrors, or a second distance from the array of micro-mirrors to the powder bed is selected to control a resolution of fusing areas in the powder bed.
An example printer includes a light source to emit uncollimated light, a first array of micro-mirrors positioned to direct the uncollimated light toward a first portion of a powder bed, wherein at least one of a first distance from the light source to the first array of micro-mirrors, or a second distance from the first array of micro-mirrors to the powder bed is selected to control a first resolution of fusing areas in the first portion of the powder bed, and a second array of micro-mirrors positioned to direct the uncollimated light toward a second portion of the powder bed, wherein at least one of a third distance from the light source to the second array of micro-mirrors, or a fourth distance from the second array of micro-mirrors to the powder bed is selected to control a second resolution of fusing areas in the second portion of the powder bed.
In some examples, the second distance is selected to be different from first distance, and the second resolution is controlled to be the first resolution.
Any references, including publications, patent applications, and patents cited herein are hereby incorporated in their entirety by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.
Filing Document | Filing Date | Country | Kind |
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PCT/US2018/057326 | 10/24/2018 | WO | 00 |