WO2021171282A1

WO2021171282A1 - System, method and computer readable medium for three-dimensional (3d) printing

Info

Publication number: WO2021171282A1
Application number: PCT/IL2021/050045
Authority: WO
Inventors: Jon DONNER; Eyal Shelef; Hotam LEYZEROVICH; Gal MILSHTEIN; Tovit NIZER; Tal SELA; Yaniv GERSHONI; Assaf GREEN; Ran Asher Peleg
Original assignee: Nanofabrica Ltd.
Priority date: 2020-02-27
Filing date: 2021-01-14
Publication date: 2021-09-02

Abstract

A method for a three-dimensional (3D) printing includes obtaining a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; dividing each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that a movable projector is capable of projecting in a single projection; determining, by the controller, for a plurality of given regions a stabilization time-period; causing the movable projector to (a) move to a respective position enabling the movable projector to project to the respective given region, if required, (b) wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; after completion of a given layer, moving a movable stage, to enable printing of a subsequent layer of the horizontal layers.

Description

SYSTEM, METHOD AND COMPUTER READABLE MEDIUM FOR THREE-DIMENSIONAL (3D) PRINTING

TECHNICAL FIELD

The invention relates to a system, method and computer readable medium for three-dimensional (3D) printing.

BACKGROUND

3D printing techniques (otherwise known as additive manufacturing, rapid prototyping, or layered manufacturing) enable fabrication of customized/complex objects without the need for molds or machining. The strategy behind the 3D printing techniques (also known as 3D photopolymerization) is based on using monomers/oligomers in a liquid state that can be cured/photopolymerized upon exposure to light source of specific wavelength and form thermosets.

Stereolithography, is one of several technologies used to create 3D-printed objects. These technologies differ mainly by the light source they use. Digital Light Processing (DLP) is one descendant of SLA (Stereolithographic Apparatus) known in the art. The DLP technique utilizes a digital micromirror device (DMD) or a panel of micrometer-sized LED lights.

Typically, DLP printers have four main parts: a liquid receptacle Tillable with photosensitive materials (e.g. photopolymers, radiation-curable resins, and liquid), a building platform, a light source and a computer controlling the latter two. DLP printers can either have a bottom-up or top-down orientation.

There are many ways to print a 3D object, most of them utilize digitalized representations thereof such as computer aided design (CAD) files. Since additive manufacturing works by adding one layer of material on top of the other, CAD models are typically sliced into layers before being printed in 3D, in order to provide the 3D- printer with the required information for each layer to be printed. Once the 3D printer is loaded with the required information, a light source is focused on a photosensitive material which causes a photopolymerization thereof (that is, a light-induced polymerization (i.e. the photosensitive material solidifies)) thereby forming the first layer of the 3D-printed object. Next, the building platform is lowered or elevated, depend on printer's orientation, exposing a new surface layer of liquid polymer. The light source traces the new surface layer which instantly solidifies therefrom. This process is repeated until the desired object has been formed.

In terms of spatial resolution of 3D printing, there are three dimensions to consider: the two planar 2D dimensions (X and Y) and the third vertical Z dimension that makes the 3D printing. Z resolution is defined by the layer thicknesses a 3D printer can produce. In DLP printer, XY resolution is defined by the pixel size (i.e. squared voxels), the smallest feature the light source can reproduce within a single layer. One challenge of stereolithography is to improve its spatial resolution while maintaining or enlarging build volume, as there is a trade-off between the two. Accuracy, precision, and print quality are also parameters to be considered when printing small, detailed pieces like jewelry. When printing larger objects, the forces exerted on the objects increase exponentially as a cured layer separates from the liquid receptacle.

While many 3D-printing techniques attempt to address these issues and provide accurate printed objects, the levels of accuracy require improvement. Thus, there is yet a growing need for a new system, method and computer readable medium for three- dimensional (3D) printing.

References considered to be relevant as background to the presently disclosed subject matter are listed below. Acknowledgement of the references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

US Patent application No. US2018/0029299 published on February 1, 2018 discloses a method of printing a three-dimensional part includes dividing each of a plurality of layers of a model of the three-dimensional part into a plurality of passes, where each of the plurality of passes is separated from one or more adjacent passes by a gap. The gap between passes in a first layer is offset from the gap between passes in an adjacent layer, such that the gap between passes in the first layer does not align with or stack with the gap between passes in the adjacent layer.

US Patent application No. US2015/0355553 published on December 10, 2015 discloses a method for producing a volume object by lithography, comprising a projection of the projection image onto a plane to be illuminated of the layer of material, which involves: moving the mask in a movement having a component along an oblique axis forming an angle with the plane to be illuminated, and transforming a movement of the mask having a component along the oblique axis forming the angle with the plane to be illuminated into a displacement of the projection image on the plane to be illuminated along the first direction of the displacement contained in the plane to be illuminated by means of a mirror that reflects the projection image coming from the mask towards the plane to be illuminated.

US Patent application No. US2019/0022941 published on January 24, 2019 discloses a digital light processing (DLP) three-dimensional (3D) printing system includes a container containing a solidifiable material; a platform contacting a portion of the solidifiable material; a projector projecting an electromagnetic radiation on the solidifiable material to form a solidified layer; and an optical component between the projector and the platform; wherein the optical component is rotated to shift the electromagnetic radiation during the formation the solidified layer, thus forming a rounded edge and an enlarged area of the solidified layer. A digital light processing (DLP) three-dimensional (3D) printing method is also disclosed.

CN Patent No. CN104669625 granted on June 9, 2017 discloses a kind of photocuring 3 D-printing method and printing equipment based on projection, and Method of printing is referred specifically to Optical projection system successively scanning and printing solidification under control of the control system, when printing every layer, every layer of whole pattern to be printed is completed using the projection breadth obtained by rectilinear movement optical projection system in the horizontal plane, and projection breadth is carried out horizontal linear movement by preset path. When mobile, control system obtains the coordinate position of the projection breadth institute projected area in real time, and controls the projection system projects to go out local pattern corresponding with the coordinate position, completes the printing solidification of the local pattern. Using the projection breadth obtained by rectilinear movement optical projection system in the horizontal plane, i.e., portable to project, it can realize the photocuring 3 D-printing of large format to the present invention, and ensure that the printing precision and high efficiency of projecting apparatus itself, improve the printing precision of whole product.

GENERAL DESCRIPTION

In accordance with a first aspect of the presently disclosed subject matter, there is provided a three-dimensional (3D) printing system, comprising: a movable projector capable of moving on a two-dimensional (2D) plane; a liquid receptacle tillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector; a movable stage capable of moving perpendicularly to the 2D plane within the liquid receptacle; and a controller configured to: obtain a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; divide each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that the movable projector is capable of projecting in a single projection; for each layer, perform the following: determine, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, cause the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) proj ect the respective proj ection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, move the movable stage to enable printing of a subsequent layer of the horizontal layers, if any.

In some cases, the stabilization time-period is determined based on the projection pattern defined by the corresponding region.

In some cases, upon the projection pattern defined by the corresponding region being a full projection pattern so that the entire corresponding region is projected by the movable projector, the stabilization time period is zero.

In some cases, at least part of the regions having empty projection pattern, that does not require projection by the movable projector, are skipped.

In some cases, the division of the layers to the regions is performed so that each given layer of the layers is divided (a) differently than a preceding layer of the layers, preceding the given layer, if any, and (b) differently than a subsequent layer of the layers, subsequent to the given layer, if any.

In some cases, at least one pair of adjacent regions of the regions have an overlapping portion, and wherein the projection patterns defined by the at least one pair of adjacent regions include an interlocking portion within the overlapping portion.

In some cases, the controller is further configured to wait a second stabilization time-period after moving the movable stage for the movable stage to stabilize, before starting to print the subsequent layer. In some cases, the movable projector is a Digital Light Processing (DLP) projector.

In accordance with a second aspect of the presently disclosed subject matter, there is provided a method for a three-dimensional (3D) printing, the method comprising: obtaining, by a controller, a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; dividing, by the controller, each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that a movable projector is capable of projecting in a single projection, wherein the movable projector is capable of moving on a two-dimensional (2D) plane; for each layer, the method further comprises: determining, by the controller, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, causing, by the controller, the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, moving, by the controller, a movable stage, capable of moving perpendicularly to the 2D plane within a liquid receptacle, to enable printing of a subsequent layer of the horizontal layers, if any, wherein the liquid receptacle is tillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector.

In some cases, at least part of the regions having empty projection pattern, that does not require projection by the movable projector, are skipped. In some cases, the division of the layers to the regions is performed so that each given layer of the layers is divided (a) differently than a preceding layer of the layers, preceding the given layer, if any, and (b) differently than a subsequent layer of the layers, subsequent to the given layer, if any.

In some cases, the method further comprising waiting a second stabilization time-period after moving the movable stage for the movable stage to stabilize, before starting to print the subsequent layer.

In some cases, the movable projector is a Digital Light Processing (DLP) projector.

In accordance with a third aspect of the presently disclosed subject matter, there is provided a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, executable by a controller to perform a method for three-dimensional (3D) printing, the method comprising: obtaining, by a controller, a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; dividing, by the controller, each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that a movable projector is capable of projecting in a single projection, wherein the movable projector is capable of moving on a two-dimensional (2D) plane; for each layer, the method further comprises: determining, by the controller, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, causing, by the controller, the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, moving, by the controller, a movable stage, capable of moving perpendicularly to the 2D plane within a liquid receptacle, to enable printing of a subsequent layer of the horizontal layers, if any, wherein the liquid receptacle is tillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the presently disclosed subject matter and to see how it may be carried out in practice, the subject matter will now be described, by way of non limiting examples only, with reference to the accompanying drawings, in which:

Fig. l is a block diagram schematically illustrating one example of a system for three-dimensional (3D) printing, in accordance with the presently disclosed subject matter;

Fig. 2 is a flowchart illustrating one example of a sequence of operations carried out for three-dimensional (3D) printing, in accordance with the presently disclosed subject matter; and

Figs. 3A and 3B are schematic illustrations of exemplary projection patterns.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the presently disclosed subject matter. However, it will be understood by those skilled in the art that the presently disclosed subject matter may be practiced without these specific details. In other instances, well- known methods, procedures, and components have not been described in detail so as not to obscure the presently disclosed subject matter.

In the drawings and descriptions set forth, identical reference numerals indicate those components that are common to different embodiments or configurations.

Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “providing”, “obtaining”, "moving", "comparing", " stabilizing", "dividing", "determining", "causing", "projecting" or the like, include action and/or processes of a computer that manipulate and/or transform data into other data, said data represented as physical quantities, e.g. such as electronic quantities, and/or said data representing the physical objects. The terms “computer”, “processor”, “processing resource”, “processing circuitry” and “controller” should be expansively construed to cover any kind of electronic device with data processing capabilities, including, by way of non-limiting example, a personal desktop/laptop computer, a server, a computing system, a communication device, a smartphone, a tablet computer, a smart television, a processor (e.g. digital signal processor (DSP), a microcontroller, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc.), a group of multiple physical machines sharing performance of various tasks, virtual servers co- residing on a single physical machine, any other electronic computing device, and/or any combination thereof.

The operations in accordance with the teachings herein may be performed by a computer specially constructed for the desired purposes or by a general-purpose computer specially configured for the desired purpose by a computer program stored in a non-transitory computer readable storage medium. The term "non-transitory" is used herein to exclude transitory, propagating signals, but to otherwise include any volatile or non-volatile computer memory technology suitable to the application.

As used herein, the phrase "for example," "such as", "for instance" and variants thereof describe non-limiting embodiments of the presently disclosed subject matter. Reference in the specification to "one case", "some cases", "other cases" or variants thereof means that a particular feature, structure or characteristic described in connection with the embodiment(s) is included in at least one embodiment of the presently disclosed subject matter. Thus, the appearance of the phrase "one case", "some cases", "other cases" or variants thereof does not necessarily refer to the same embodiment(s).

It is appreciated that, unless specifically stated otherwise, certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

In embodiments of the presently disclosed subject matter, fewer, more and/or different stages than those shown in Fig. 2 may be executed. In embodiments of the presently disclosed subject matter one or more stages illustrated in Fig. 2 may be executed in a different order and/or one or more groups of stages may be executed simultaneously. Figs. 1 illustrate a general schematic of the system architecture in accordance with an embodiment of the presently disclosed subject matter. Each module in Figs. 1 can be made up of any combination of software, hardware and/or firmware that performs the functions as defined and explained herein. The modules in Figs. 1 may be centralized in one location or dispersed over more than one location. In other embodiments of the presently disclosed subject matter, the system may comprise fewer, more, and/or different modules than those shown in Figs. 1.

Any reference in the specification to a method should be applied mutatis mutandis to a system capable of executing the method and should be applied mutatis mutandis to a non-transitory computer readable medium that stores instructions that once executed by a computer result in the execution of the method.

Any reference in the specification to a system should be applied mutatis mutandis to a method that may be executed by the system and should be applied mutatis mutandis to a non-transitory computer readable medium that stores instructions that may be executed by the system.

Any reference in the specification to a non-transitory computer readable medium should be applied mutatis mutandis to a system capable of executing the instructions stored in the non-transitory computer readable medium and should be applied mutatis mutandis to method that may be executed by a computer that reads the instructions stored in the non-transitory computer readable medium.

Bearing this in mind, attention is drawn to Fig. 1, showing a block diagram schematically illustrating one example of a system 100 for three-dimensional (3D) printing, according to one example of the presently disclosed subject matter.

The system for or three-dimensional (3D) printing 100 (also referred to herein as “system”) includes a movable projector 102, a liquid receptacle 104, a photosensitive material 106, a movable stage 108, a linear motor 110 and at least one controller 112.

Controller 112 can be one or more processing units (e.g. central processing units), microprocessors, microcontrollers or any other computing devices or modules, including multiple and/or parallel and/or distributed processing units, which are adapted to independently or cooperatively process data for controlling relevant resources of the system for three-dimensional (3D) printing 100 and for enabling operations related to resources thereof. In order to perform a 3D-printing of a desired object, a digital representation thereof should be loaded/provided to the controller 112. The digital representation may be created using a Computer-aided design (CAD) or Computer-aided manufacturing (CAM) software or the like.

The controller 112 comprises a printing control module 114 configured to perform a process for three-dimensional (3D) printing, as further detailed herein with respect to Fig 2. The printing control module 114 is configured to control, inter alia, vertical movement of the linear motor 110 along a Z-axis and horizontal movement of the movable projector 102 in X-Y plane. The linear motor 110 is configured for sequential and/or controlled shift of the movable stage 108 along Z-axis.

As depicted in Fig. 1, the system for three-dimensional (3D) printing 100 has a bottom-up orientation (while noting that this is non-limiting and it can also have any other orientation, mutatis mutandis). Hence, when the printing process starts, the movable stage 108 is immersed within the photosensitive material 106 from above, accommodated by the liquid receptacle 104, leaving a gap therebetween (i.e. between the movable stage 108 and the bottom surface of the liquid receptacle 104). This way a layer of a desired thickness of the photosensitive material 106 is exposed to the movable projector 102 located underneath the liquid receptacle 104. The movable projector 102 is configured to project (i.e. irradiate) a beam of electromagnetic radiation (e.g. in visible or ultraviolet spectrum) on the exposed layer of the photosensitive material 106 thereby causing photopolymerization thereof (i.e. the layer solidifies). After the first layer, the linear motor 110 is configured to elevate the movable stage 108 according to the layer thickness (as layer thickness may vary throughout printing, e.g. in a range of about 1-10 micron or more) thereby allowing additional photosensitive material 106 to flow underneath the solidified layer adhered thereto. This process is repeated until the desired object is complete.

According to certain examples of the presently disclosed subject matter, the movable projector 102 may be a Digital Light Processing (DLP) projector.

It is to be noted that in other cases, the system for three-dimensional (3D) printing 100 may have a top-down orientation or any other orientation capable of performing sequence of operations of the presently disclosed subject matter, mutatis mutandis.

It is to be noted that in some cases, system 100 may further include a network interface device (NID). System 100 may also include a video display unit (e.g. flat panel display, such as OLED, or liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g. a keyboard), a cursor control device (e.g. a mouse), and a signal generation device (e.g. a speaker). System 100 may further include a memory. The memory may include a machine-accessible storage medium (or more specifically a computer-readable storage medium) on which stored one or more sets of instructions (e.g. software) embodying any one or more of the methodologies or functions described herein. The software may also reside, completely or at least partially, within the memory and/or within the controller 112 during execution thereof by the system 100, the memory and the controller 112 also constituting machine- readable storage media. The software may further be transmitted or received over a network via the network interface device.

It is to be further noted that the term “machine -readable storage medium” should be taken to include a single medium or multiple media (e.g. centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present presently disclosed subject matter the term “machine- readable storage medium” shall accordingly be taken to include, but not limited to, solid-state memories, and optical and magnetic media.

Turning to Fig. 2, there is shown a flowchart illustrating one example of a sequence of operations carried out for three-dimensional (3D) printing, in accordance with the presently disclosed subject matter.

According to certain examples of the presently disclosed subject matter, system for three-dimensional (3D) printing 100 can be configured to perform a three- dimensional (3D) printing process 200, e.g. utilizing a printing control module 114.

For this purpose, the system for three-dimensional (3D) printing can be configured to obtain a 3D model for printing, the 3D model comprised of a plurality of horizontal layers (block 210).

The plurality of horizontal layers represents cross-sections of the 3D model to be printed, i.e. each horizontal layer represents a cross-section (e.g. surface geometry), of the 3D model, to be printed by system 100. The system 100 can be further configured to divide each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that the movable projector is capable of projecting in a single projection (block 220).

The plurality of regions of each horizontal layer define projection pattern that corresponds to the cross-section (e.g. surface geometry) of the 3D model, to be printed by system 100. The movable projector 102 can be configured to project a whole region in a single projection, or portion thereof, in accordance with the respective projection pattern of the projected region. Additionally, or alternatively, the movable projector can be configured not to project a specific region, in accordance with the respective projection pattern of the specific region.

In some cases, the division of the layers to the regions can be performed so that each given layer of the layers is divided (a) differently than a preceding layer of the layers, preceding the given layer, if any, and (b) differently than a subsequent layer of the layers, subsequent to the given layer, if any. When printing one layer of the 3D model, divided into regions, gaps of uncured or under-cured (e.g. green state) photosensitive material 106 located between adjacent regions may occur. According to the presently disclosed subject matter, the controller 112 can be configured to divide each given layer of the layers in a different manner. That is, adjacent layers can have different division into regions so that gaps of uncured or under-cured photosensitive material 106 located between adjacent regions in one layer can be shifted to other locations in the preceding and/or subsequent layer to said layer. This way, gaps of uncured or under-cured photosensitive material 106 do not accumulate to form one continuous gap along the vertical Z-axis resulting in weak and fragile 3D model (e.g. unable to withstand shear force along Z-axis, pressure, etc.). In fact, such partial exposure of said gaps to electromagnetic radiation enables to build strong and stable 3D model. In addition, such manner of operation may yield a partial exposure to electromagnetic radiation of the gaps of uncured or under-cured photosensitive material 106 located between adjacent regions in one layer during the printing process of the subsequent layer to said layer, thereby optionally curing said gaps.

It is to be noted that in some cases it is advantageous to have an overlapping portion between at least one pair of adjacent regions of the regions, and to have the projection patterns defined for the adjacent regions include an interlocking portion within the overlapping portion. For this purpose, the controller 112 can be configured to divide each layer of the horizontal layers to a plurality of regions so that at least one pair of adjacent regions of the regions can have an overlapping portion. That is, one portion of one region can be co-located with a corresponding portion of a second region of the pair of adjacent regions. Additionally, projection patterns defined by said adjacent regions can include an interlocking portion within the overlapping portion. That is, the overlapping portion of the at least one pair of adjacent regions may have a form of projections and recesses (e.g. having parts that overlap or fit together). Exemplary interlocking portions within the overlapping portions of the at least one pair of adjacent regions are depicted in Figs 3A and 3B. Fig. 3A illustrates projection patterns of one pair of adjacent regions 32 and 34 having an overlapping portion 36 wherein projections 38 of region 34 interlock (i.e. fit together) with recesses 40 of region 32 (and vice versa) during the printing process of system 100. Fig. 3B illustrates another example, with accordance to the presently disclosed subject matter, of projection patterns having overlapping portions in a form of projections 42 and recesses 44.

It is to be noted that interlocking portions within the overlapping portions depicted in Figs 3 A and 3B were chosen merely for readily understanding the true spirit of the subject matter yet other forms (e.g. shapes) of interlocking portions within the overlapping portions may be used between adjacent regions.

In some cases, the system 100 can be further configured to perform the following blocks 230, 240 and 250 for each layer of the 3D model (block 225):

In block 230, the system 100 determines, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region.

According to certain examples of the presently disclosed subject matter, 3D- printing of a 3D model can be performed by movement of the movable projector 102 in the X-Y plane. Said movement of the movable projector 102 can be controlled, via wired or wireless communication, by the controller 112 in accordance with the projection patterns of the plurality of regions in the horizontal layer that is being projected.

System 100 can be configured to determine a stabilization time-period that is required for stabilizing the movable projector 102 after its movement to a position wherein the respective given region is to be projected. That is, each given region of the plurality of given regions of the corresponding layer can have a corresponding stabilization time-period, wherein the stabilization time-period can be determined based on the projection pattern defined by the corresponding region. It is to be noted that said stabilization time-periods may differ between the given regions. Each stabilization time-period may be milliseconds, microseconds or less, while noting that in case the stabilization time-period is larger than zero, during such stabilization time-period, movable projector 102 is not actively moved by the moving mechanism responsible for its movement (i.e. the moving mechanism stops moving the movable projector 102). In some cases, stabilization time-period may be zero or nearly zero. For example, in cases wherein upon the projection pattern defined by the corresponding region being a full projection pattern so that the entire corresponding region is projected by the movable projector 102, the stabilization time period is zero. In these cases, the movable projector 102 can be configured to perform continuous movement and projection across the region associated with the full projection pattern, i.e. without stopping upon arrival of the movable projector 102 to a position enabling the movable projector 102 to project the respective given region and waiting stabilization time-period.

In some cases, it is not enough that the projection pattern defined by the corresponding region being a full projection pattern in order to eliminate the need of a stabilization time period (i.e. setting it to zero). For example, in cases where a certain portion, adjacent to said respective given region within one or more regions adjacent to said respective given region is not to be printed on (i.e. the projection pattern is empty in such portion) - if the stabilization time period is set to zero - such portions, that are supposed not to be printed on according to the respective projection pattern, may be printed on, due to vibrations of the movable projector 102 that does not arrive at a full stop before projecting the full projection pattern. In such cases, the stabilization time period is determined to be higher than zero, in order to eliminate erroneous printing on adjacent portions (adjacent to the respective given region) of adjacent regions (adjacent to the respective given region).

It is to be noted that the size of the adjacent portions (adjacent to the respective given region) of the adjacent regions (adjacent to the respective given region) can be determined so that any potential vibration of the movable projector 102 will not result in printing outside such portion. In some cases, the size of the portion can depend on the movement speed of the movable projector 102, so that the higher the speed - the larger the portion, and vice versa. Additionally, or alternatively, in cases where at least some of the regions having empty projection pattern, that does not require projection by the movable projector 102, such regions can be skipped. In these cases, the movable projector 102 can be configured to perform a continuous movement across the region associated with the empty projection pattern, i.e. without stopping upon arrival of the movable projector 102 to a position enabling the movable projector 102 to project the respective given region and waiting stabilization time-period.

Such framework (of waiting a stabilization time-period where required on one hand and continuously moving without waiting stabilization time-period where it is not required on the other hand) combines the capabilities of reducing system distortions in each of the horizontal layers and increasing raw print speed of the three-dimensional (3D) printing system 100, in comparison to other solutions known in the art.

In block 240, the system 100, for each of the given regions, causes the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify.

After completion of a given layer of the horizontal layers, the system 100 moves the movable stage 108 to enable printing of a subsequent layer of the horizontal layers, if any (block 250).

As detailed hereinabove, with respect to Fig.1, the movable stage 108 is configured to be elevated according to the horizontal layer thickness to allow additional photosensitive material 106 to flow underneath the solidified layer adhered thereto. Said movement of the movable stage 108 can be controlled, via wired or wireless communication, by the controller 112 in accordance with the presently disclosed subject matter.

In some cases, the controller 112 can be further configured to wait a second stabilization time-period after moving the movable stage 108 for the movable stage 108 to stabilize, before starting to print the subsequent layer. Movement of the movable stage 108 may cause vibrations thereof and optionally of system 100. Therefore, in order to avoid distortions in the horizontal layer(s) while printing the 3D model, the controller 112 can be configured to wait a second stabilization time-period after moving the movable stage 108 in order to allow the movable stage 108 to stabilize.

The second stabilization time-period may be milliseconds, microseconds or less, while noting that in case the stabilization time-period is larger than zero, during such stabilization time-period, movable stage 108 is not actively moved by the linear motor 110.

In some cases, second stabilization time-period may be zero or nearly zero.

According to certain examples of the presently disclosed subject matter, an object printed based on the 3D model can have dimensions of up to five centimeters in length, five centimeters in depth and ten centimeter in height, while having an accuracy less than one micron. Nevertheless, it is to be noted that according to other examples of the presently disclosed subject matter, bigger and/or smaller dimensions of the 3D model can be printed by system 100 with the accuracy of less than one micron. For example, large volume 3D model can be printed with dimensions of up to 700X700X700mm, or even more, with the accuracy of less than one micron.

It is to be noted that, with reference to Fig. 2, some of the blocks can be integrated into a consolidated block or can be broken down to a few blocks and/or other blocks may be added. It is to be further noted that some of the blocks are optional. It should be also noted that whilst the flow diagram is described also with reference to the system elements that realizes them, this is by no means binding, and the blocks can be performed by elements other than those described herein.

It is to be understood that the presently disclosed subject matter is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The presently disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present presently disclosed subject matter.

It will also be understood that the system according to the presently disclosed subject matter can be implemented, at least partly, as a suitably programmed computer. Likewise, the presently disclosed subject matter contemplates a computer program being readable by a computer for executing the disclosed method. The presently disclosed subject matter further contemplates a machine-readable memory tangibly embodying a program of instructions executable by the machine for executing the disclosed method.

Examples of the presently disclosed subject matter may be provided as a computer program product, or software, that may include a machine-readable medium having stored thereon instructions, which may be used to program a computer system (or other electronic devices) to perform a process according to the presently disclosed subject matter. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g. a computer). For example, a machine-readable (e.g. computer readable) medium includes a machine (e.g. a computer) readable storage medium (e.g. read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g. computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

Fig. 1 illustrates a diagrammatic representation of a system in the exemplary form of a machine including hardware and software such as e.g. set of instructions, causing the system to perform any one or more of the above techniques. In alternative examples, the machine may be connected (e.g. networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines (e.g. computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.

In the foregoing specification, the presently disclosed subject matter has been described with reference to specific examples of embodiments of the presently disclosed subject matter. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the presently disclosed subject matter as set forth in the appended claims.

Also, the presently disclosed subject matter is not limited to physical devices or units implemented in nonprogrammable hardware but can also be applied in programmable devices or units able to perform the desired device functions by operating in accordance with suitable program code, such as mainframes, minicomputers, servers, workstations, personal computers, notepads, personal digital assistants, electronic games, and other embedded systems, cell phones and various other wireless devices, commonly denoted in this application as ‘computer systems’.

However, other modifications, variations and alternatives are also possible. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.

While certain features of the presently disclosed subject matter have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the presently disclosed subject matter.

Claims

CLAIMS:

1. A three-dimensional (3D) printing system, comprising: a movable projector capable of moving on a two-dimensional (2D) plane; a liquid receptacle fillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector; a movable stage capable of moving perpendicularly to the 2D plane within the liquid receptacle; and a controller configured to: obtain a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; divide each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that the movable projector is capable of projecting in a single projection; for each layer, perform the following: determine, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, cause the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, move the movable stage to enable printing of a subsequent layer of the horizontal layers, if any.

2. The 3D printing system of claim 1, wherein the stabilization time-period is determined based on the projection pattern defined by the corresponding region.

3. The 3D printing system of claim 2, wherein upon the projection pattern defined by the corresponding region being a full projection pattern so that the entire corresponding region is projected by the movable projector, the stabilization time period is zero.

4. The 3D printing system of claim 1, wherein at least part of the regions having empty projection pattern, that does not require projection by the movable projector, are skipped.

5. The 3D printing system of claim 1, wherein the division of the layers to the regions is performed so that each given layer of the layers is divided (a) differently than a preceding layer of the layers, preceding the given layer, if any, and (b) differently than a subsequent layer of the layers, subsequent to the given layer, if any.

6. The 3D printing system of claim 1, wherein at least one pair of adjacent regions of the regions have an overlapping portion, and wherein the projection patterns defined by the at least one pair of adjacent regions include an interlocking portion within the overlapping portion.

7. The 3D printing system of claim 1, wherein the controller is further configured to wait a second stabilization time-period after moving the movable stage for the movable stage to stabilize, before starting to print the subsequent layer.

8. The 3D printing system of claim 1, wherein the movable projector is a Digital Light Processing (DLP) projector.

9. A method for a three-dimensional (3D) printing, the method comprising: obtaining, by a controller, a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; dividing, by the controller, each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that a movable projector is capable of projecting in a single projection, wherein the movable projector is capable of moving on a two-dimensional (2D) plane; for each layer, the method further comprises: determining, by the controller, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, causing, by the controller, the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, moving, by the controller, a movable stage, capable of moving perpendicularly to the 2D plane within a liquid receptacle, to enable printing of a subsequent layer of the horizontal layers, if any, wherein the liquid receptacle is tillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector.

10. The method of claim 10, wherein the stabilization time-period is determined based on the projection pattern defined by the corresponding region.

11. The method of claim 10, wherein upon the projection pattern defined by the corresponding region being a full projection pattern so that the entire corresponding region is projected by the movable projector, the stabilization time period is zero.

12. The method of claim 10, wherein at least part of the regions having empty projection pattern, that does not require projection by the movable projector, are skipped.

13. The method of claim 10, wherein the division of the layers to the regions is performed so that each given layer of the layers is divided (a) differently than a preceding layer of the layers, preceding the given layer, if any, and (b) differently than a subsequent layer of the layers, subsequent to the given layer, if any.

14. The method of claim 10, wherein at least one pair of adjacent regions of the regions have an overlapping portion, and wherein the projection patterns defined by the at least one pair of adjacent regions include an interlocking portion within the overlapping portion.

15. The method of claim 10, wherein the method further comprising waiting a second stabilization time-period after moving the movable stage for the movable stage to stabilize, before starting to print the subsequent layer.

16. The method of claim 10, wherein the movable projector is a Digital Light Processing (DLP) projector.

17. A non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, executable by a controller to perform a method for three-dimensional (3D) printing, the method comprising: obtaining, by a controller, a 3D model for printing, the 3D model comprised of a plurality of horizontal layers; dividing, by the controller, each layer of the horizontal layers to a plurality of regions, each region defining a respective projection pattern that a movable projector is capable of projecting in a single projection, wherein the movable projector is capable of moving on a two-dimensional (2D) plane; for each layer, the method further comprises: determining, by the controller, for a plurality of given regions of the regions of the corresponding layer, a stabilization time-period for stabilizing the movable projector after movement of the movable projector to a position enabling the movable projector to project to the respective given region; for each of the given regions, causing, by the controller, the movable projector to (a) move to a respective position on the 2D plane to the position enabling the movable projector to project to the respective given region, if required, (b) upon the stabilization time-period associated with the corresponding given region being more than zero, wait the stabilization time-period associated with the corresponding given region, and (c) project the respective projection pattern, thereby causing part of the photosensitive material defined by the projection pattern of the corresponding given region to solidify; and after completion of a given layer of the horizontal layers, moving, by the controller, a movable stage, capable of moving perpendicularly to the 2D plane within a liquid receptacle, to enable printing of a subsequent layer of the horizontal layers, if any, wherein the liquid receptacle is tillable with photosensitive material designed to solidify under the influence of radiation generated by the movable projector.