High-resolution printing system and method for aligning pixelated tiles

Abstract

A three-dimensional (3D) printing apparatus is configured to manufacture 3D articles in layers and in a layered manner. The 3D printing apparatus includes a projector configured to selectively illuminate a photosensitive device along a horizontal construction plane defined along the X and Y axes. The projector is coupled to a lateral movement mechanism configured to scan the projector laterally along movement coordinates in the X' and Y' axes. The movement coordinates in the X' and Y' axes are not precisely aligned in the X and Y axes, respectively. For each layer of the 3D article, the projector is configured to illuminate an array of adjacent pixelated tiles in the construction plane. Before illuminating the array of tiles, the projector is configured to operate a camera to align the leading and trailing edges of the tiles along the X' and Y' axes, respectively.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Application No. 63 / 471,384, filed on June 6, 2023, the entire content of which is incorporated herein by reference.

[0002] This disclosure relates to apparatuses and methods for manufacturing solid three - dimensional (3D) articles layer - by - layer from photosensitive materials such as radiation - curable materials. More particularly, this disclosure relates to an improved high - resolution apparatus that uses an array of pixelated tiles having aligned leading and trailing edges to cure individual layers.

Background Art

[0003] Three - dimensional (3D) printers are rapidly increasing in use for manufacturing customized articles. One class of 3D printers includes stereolithography printers that operate on the general principle of selective curing and hardening of photosensitive fluids such as radiation - curable (i.e., photocurable) liquids. One type of stereolithography system has a containment vessel that holds a photosensitive fluid, such as a photocurable liquid, a movement mechanism coupled to a support tray, and an optical engine. The stereolithography system forms a three - dimensional (3D) manufactured article by selectively curing a layer of a photosensitive fluid, such as a photocurable liquid, along a build plane. There is a desire to manufacture articles having feature sizes of 10 microns or less. One challenge is aligning very high - resolution steps and being able to repeat projected image tiles.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] One aspect of the present disclosure includes a method for manufacturing a three-dimensional (3D) article, comprising operating a 3D printing apparatus. The 3D printing apparatus has a projector configured to selectively irradiate a photosensitive fluid along a horizontal construction plane defined along the X and Y axes. The projector is coupled to a lateral movement mechanism configured to scan the projector laterally along movement coordinates in the X' and Y' axes. The movement coordinates in the X' and Y' axes are not precisely aligned with the X and Y axes, respectively. The projector is configured to irradiate an array of adjacent pixelated tiles within the construction plane, thereby curing each portion of the photosensitive fluid. This method involves (1) providing a camera having a camera field of view (CFV) that is lateral within the construction plane; (2) positioning a projector along X' and Y' axis movement coordinates within the camera field of view to position the front edge of a first pixelated tile within the camera field of view; (3) operating the projector to illuminate the front edge of the first pixelated tile; (4) operating the camera to image the front edge of the first pixelated tile; and (5) aligning the rear edge of a second pixelated tile with the front edge of the first pixelated tile. The method comprises: (6) translating the projector along the Y' axis to position a second pixelated tile adjacent to the tile; (7) operating the projector to illuminate at least the trailing edge of the second pixelated tile; (8) operating the camera to image the trailing edge of the second pixelated tile; (9) calculating the alignment error along the X' and Y' axes of the trailing edge relative to the front edge; and (10) remapping the movement coordinates in the X' and Y' axes to align the front edge of the first pixelated tile with the trailing edge of the second pixelated tile.

[0006] In one embodiment, operating the projector involves projecting a first pixelated tile and a second pixelated tile upward onto the construction plane. The 3D printing apparatus has a support surface that at least partially surrounds the construction plane laterally. Providing a camera involves mounting an image capturing plate on the support surface. The image capturing plate has a camera facing downward.

[0007] In another implementation, operating the projector involves projecting a first pixelated tile and a second pixelated tile upward onto the construction plane. The 3D printing apparatus has a support surface that at least partially surrounds the construction plane laterally. The method comprises loading a construction container onto the support surface and filling the construction container with a photosensitive fluid before or after loading the construction container onto the support surface. The 3D printing apparatus has an elevator connected to a vertical movement mechanism. The method further comprises loading a construction platform onto the elevator. The construction platform has a construction plate. The construction container has a transparent member that provides a lower limit for the photosensitive fluid. The method further comprises operating the vertical movement mechanism, the lateral movement mechanism and the projector to produce a 3D article having an array of selectively cured layers formed on the construction plane above the transparent member. This method further comprises operating a vertical movement mechanism to position the underside of the construction plate or a previous layer of the 3D object on the construction plane, and operating a lateral movement mechanism and a projector to illuminate an array of pixelated tiles across the construction plane so as to selectively illuminate (cure) layers of an array of selectively cured layers, which are continuous tiles aligned along the leading and trailing edges. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an isometric view of a three-dimensional (3D) printing apparatus according to one embodiment. [Figure 2] Figure 2 is a top view of a part of a three-dimensional (3D) printing apparatus according to one embodiment. [Figure 3] Figure 3 is a simplified electrical block diagram of a three-dimensional (3D) printing apparatus according to one embodiment. [Figure 4] Figure 4 is a schematic diagram of a construction plane in which an array of tiles is image-formed to create layers or slices of a 3D object. The tiles are displayed overlapping with a slight offset in position. [Figure 5]Figure 5 is a schematic diagram depicting the camera field of view (CFW) within the construction plane. Within the camera's field of view, two consecutive and misaligned tiles are displayed. [Figure 6] Figure 6 is a schematic diagram showing two misaligned tiles from Figure 5. [Figure 7] Figure 7 is a schematic diagram showing the situation after the tiles from Figure 6 are aligned along the axial movement coordinates X’ and Y’. [Figure 8] Figure 8 is a flowchart of a method for manufacturing a 3D article according to an embodiment. [Figure 9] Figure 9 is a flowchart of a method for aligning pixelated image-forming tiles according to an embodiment. [Figure 10] Figure 10 is a flowchart of a method for fabricating a 3D article according to an embodiment.

Embodiments for Carrying Out the Invention

[0009] Related Applications The following patent documents can each be used to refer to the whole of this application by reference to assist in understanding this application. That is, Patent Document 1 (U.S. Patent Application Publication No. 2022 / 0370188), Patent Document 2 (U.S. Patent Application Publication No. 2022 / 0389374), Patent Document 3 (U.S. Patent Application Publication No. 2022 / 0356433), Patent Document 4 (U.S. Patent Application Publication No. 2022 / 0371268), Patent Document 5 (U.S. Patent Application Publication No. 2022 / 0354954), Patent Document 6 (U.S. Patent Application Publication No. 2022 / 0355541), Patent Document 7 (U.S. Patent Application Publication No. 2022 / 0055289), Patent Document 8 (International Publication No. 2022 / 23603030), Patent Document 9 (International Publication No. 2022 / 236061), Patent Document 10 (International Publication No. 2022 / 236119), Patent Document 11 (International Publication No. 2022 / 236125), Patent Document 12 (International Publication No. 2022 / 236103), and Patent Document 13 (International Publication No. 2022 / 046719).

[0010] Unless otherwise specified, the articles "a" or "an" mean "one or more".

[0011] FIG. 1 is an isometric view showing a three-dimensional (3D) printing apparatus 2 of one embodiment. When describing the 3D apparatus 2, axes X, Y, and Z that are perpendicular to each other will be used. Axes X and Y are generally horizontal lateral axes. Axis Z is generally a vertical axis aligned with a gravity reference. When using the term "generally", the limitation that it is "generally" true is by design and is implied to be within manufacturing tolerances. Additionally, angular axes θ-X, θ-Y, and θ-Z are rotations with respect to the X, Y, and Z axes, respectively. The 3D printing apparatus 2 has a chassis or housing 4 that supports various components having a support surface 6.

[0012] In the illustrated embodiment, a build container 8 is placed on the support surface 6. The build container 8 is configured to contain a photosensitive fluid 10, for example, a defined volume or column of a photocurable liquid. The build container 8 has a transparent sheet and / or plate 12 that defines a lower limit of the photocurable liquid 10. Also, the build container 8 has lateral walls 14 for containing the photocurable liquid 10 laterally.

[0013] In some embodiments, the photosensitive fluid, such as a photocurable liquid or ink, may be one or more of the photosensitive fluids disclosed in Patent Document 1 (U.S. Patent Application Publication No. 2022 / 0370188), Patent Document 3 (U.S. Patent Application Publication No. 2022 / 0356433), Patent Document 6 (U.S. Patent Application Publication No. 2022 / 0355541), Patent Document 2 (U.S. Patent Application Publication No. 2022 / 0389374), Patent Document 4 (U.S. Patent Application Publication No. 2022 / 0371268), and Patent Document 5 (U.S. Patent Application Publication No. 2022 / 0354954), each of which is incorporated herein by reference in whole. In some embodiments, the photosensitive fluid, such as a photocurable liquid or ink, may be a biocompatible bioink. In some embodiments, a photosensitive fluid, such as a photocurable liquid or ink, can be used to print a 3D model that can be a bioscaffold, as disclosed in one or more of the following: Patent Document 1 (U.S. Patent Application Publication No. 2022 / 0370188), Patent Document 3 (U.S. Patent Application Publication No. 2022 / 0356433), Patent Document 6 (U.S. Patent Application Publication No. 2022 / 0355541), Patent Document 2 (U.S. Patent Application Publication No. 2022 / 0389374), Patent Document 4 (U.S. Patent Application Publication No. 2022 / 0371268), and Patent Document 5 (U.S. Patent Application Publication No. 2022 / 0354954). In some embodiments, the 3D model can also be an artificial organ (e.g., lung, liver, kidney, heart, or part of heart) that can be used as a scaffold for tissue engineering.

[0014] The elevator 16 is connected to a vertical movement mechanism 18. The elevator 16 supports the construction platform 20. The construction platform 20 has a construction plate 22 having a lower surface, or bottom surface 24. The bottom surface 24 supports a 3D article (not shown), which also has a bottom surface 24 when it is being formed. This element 24 is defined as the bottom surface 24 of either the construction plate 22 or the 3D article during the fabrication of the 3D article. The vertical movement mechanism 18 is configured to position the construction plate 22, and therefore the bottom surface 24, vertically.

[0015] One embodiment of the vertical movement mechanism 18 has what is called an electrically operated ball bearing screw mechanism, or ball screw mechanism. The ball screw mechanism comprises a vertical screw shaft passing through a ball nut. The ball nut houses recirculating steel balls that move in parallel in the vertical direction. The vertical screw shaft has a helical passage that engages with the recirculating balls. The elevator 16 has a ball nut. A motor is connected to the vertical screw shaft and is configured to selectively rotate the vertical screw shaft. As the vertical screw shaft rotates, the action of the vertical screw shaft on the ball nut causes the elevator to move in parallel upward or downward depending on the direction of rotation. The above-described parallel movement mechanism is known as a technique for high-precision positioning along vertical, horizontal, and oblique axes. Other embodiments such as lead screw and nut systems, rack and pinion mechanisms, or electrically operated belt / pulley systems are also possible, all of which are known in techniques for linearly moving parts along various axes. All references to the movement mechanisms described herein can utilize one or more of these known methods.

[0016] Figure 2 shows a partial top view of a 3D printing apparatus 2 having some of the elements previously referenced. The projector 26 is connected to a lateral movement mechanism 28. The lateral movement mechanism 28 is configured to position, scan, and translate the projector 26 along axial movement coordinates or axes X' and Y'. The axial movement coordinates X' and Y' correspond to the lateral axes X and Y, but X' and Y' may not be precisely aligned with X and Y respectively, and may not be precisely orthogonal.

[0017] In the illustrated embodiment, the lateral movement mechanism 28 has a pair of linear motors that drive a screw or gear mechanism that provides parallel movement of the projector 26 along the X' and Y' axes. In a particular embodiment, the linear motors rotate the lead screws individually. The lead screws are screwed into nuts on the X and Y stages that support the projector 26. Thus, the rotation of the motors is converted into linear motion along the axial movement coordinates X' and Y'.

[0018] In the illustrated embodiment, the projector 26 is a projection-based light engine. The projector comprises a light source, a spatial light modulator, and a projection optical system. The light source illuminates the spatial light modulator with electromagnetic radiation having a wavelength capable of photocuring a photocurable liquid. In some embodiments, the wavelength may be in the blue to ultraviolet range. In some embodiments, the wavelength may be from 200 nm to 500 nm, or from 250 nm to 495 nm, or from 300 nm to 460 nm, or any value or partial range within these ranges. The spatial light modulator may have an array of micromirrors, each having two states: an ON state in which a small beam of light is transmitted to the projection optical system, and an OFF state in which light reaching the micromirrors is "dumped" into a light trap and does not reach the projection optical system. The projection optical system projects and focuses the small beam of received light onto a rectangular construction plane above a transparent sheet and / or plate (also called a "transparent member"). The term "transparent member" refers to an optically transparent plate or sheet, which may mean having at least 80%, at least 90%, at least 95%, at least 98%, or at least 99% absolute transmission of electromagnetic radiation from a light source at different wavelengths. In some embodiments, the transparent member may be optically transparent in the range of blue to ultraviolet wavelengths of radiation. In some embodiments, the transparent optical member may be transparent to wavelengths of 200 nm to 500 nm, 250 nm to 495 nm, or 300 nm to 460 nm. In some embodiments, the transparent member may be one or more of a flexible polymer sheet, a rigid glass plate, a rigid polymer plate, a rigid quartz plate, and other known materials. The projector 26 can form rectangular pixelated tiles of light on the construction plane.

[0019] Figure 3 is a simplified electrical block diagram of the 3D printing apparatus 2. The control unit 30 is connected to various parts of the 3D printing apparatus 2, particularly the elevator 16, the vertical movement mechanism 18, the projector 26, and the lateral movement mechanism 28. The control unit 30 has a processor 32 connected to an information storage subsystem 34 having one or more non-temporary or non-volatile storage devices. The information storage device 34 stores software instructions, when executed by the processor 32, which, among other things, operate the parts of the 3D printing system 2 having the various systems and subsystems shown in Figure 3. The control unit 30 can be a single module located in the same location as the housing or chassis 4, and / or may have modules, computers, and / or servers spaced apart or separate from the housing or chassis 4. Control units having processors and storage subsystems are well known in the art of controlling electromechanical systems.

[0020] Furthermore, the control unit 30 is connected to a camera or image acquisition device 36. The camera 36 can be mounted on an image acquisition plate 37 placed on a support surface 6, which has a downward-facing camera 36 that receives light from an upward-facing projector 26. The camera 36 is configured to provide the control unit 30 with information regarding radiation from the projector 26, which will be discussed below. The apparatus 2 is configured to manufacture or produce a 3D article 35.

[0021] Figure 4 is a schematic diagram showing the construction plane 38, which is the geometric region on which the optical engine or projector 26 operates. The projection optics typically focus on the construction plane 38. Although shown as a rectangle, the construction plane 38 can be any practical shape, including, among others, polygons, circles, ellipses, asymmetrical, or irregular shapes. In one embodiment, the construction plane 38 is a cut-out circular region. However, for illustrative purposes, the construction plane 38 is shown as a rectangle. The construction plane may be less than 0.5 millimeters (mm) above the transparent member 12.

[0022] As described above, the projector 26 can be translated along each of the two dimensions X' and Y' by the lateral movement mechanism 28. The axes X' and Y' have been described as axial movement coordinates X' and Y', which may not be exactly perpendicular to each other. The projector 26 can also define non-rectangular regions or tiles 40. The pixelated tile 40 is the region that the projector 26 selectively illuminates the construction plane 38.

[0023] An array of tiles 40 is selectively irradiated to selectively irradiate a certain area of ​​the construction plane 38. In the figure, the tiles 40 overlap to some extent due to errors in size, shape, and alignment. This is undesirable because the overlapping areas are overexposed to radiation. Alternatively, there are gaps between the tiles 40, creating a photosensitive fluid, such as a photocurable liquid, underneath before curing, which is also undesirable.

[0024] Figure 5 shows a construction plane 38 having a camera field of view (CFV) 42. The camera 36 is configured to focus on the construction plane 38 across the lateral camera field of view 42. The camera field of view 42 is a lateral region defined along axes X and Y. Figure 5 also shows two tiles 40 having a first tile 40-1 and a second tile 40-2 that are sequentially illuminated on the construction plane 38 within the camera field of view 42.

[0025] Figure 6 shows the first tile 40-1 and the second tile 40-2 in an unaligned state. The unaligned state can be caused by a lateral movement mechanism 28 having a motor and axial drive mechanism that are not precisely vertical. The unaligned state can also be caused by the tile 42 not being perfectly rectangular. As a result, a gap or overlapping zone 44 is created between the two tiles.

[0026] Arrow 45 indicates the direction 45 of the arrangement of the illustrated tiles 42. The first tile 40-1 has a leading edge 46 or 46-1 with respect to the sequential direction 45. The second tile 40-2 has a trailing edge 48 or 48-2 with respect to the sequential direction. To avoid uncured or overexposed zones 44, it is desirable to have a precise alignment between the leading edge 46-1 of the first tile 40-1 and the trailing edge 48-2 of the second tile 40-2.

[0027] Figure 7 shows the first tile 40-1 and the second tile 40-2 after remapping the coordinates X' and Y' and aligning them. In the aligned state, the front edge 46-1 of the first tile 40-1 is aligned with the rear edge 48-2 of the second tile 40-2.

[0028] Figure 8 is a flowchart of a method 50 for manufacturing a 3D article according to one embodiment. According to step 52, the camera 36 is mounted on the 3D printing apparatus 2 by stacking the image capturing plate 37 on the support surface 6. According to step 54, the control unit 30 operates the projector 26, the lateral movement mechanism 28, and the camera 26 to align the pixelated image forming tiles 40. Step 54 of the method 50 according to one embodiment is refined similarly to the method 70 in Figure 9.

[0029] According to step 56, the camera 36 is removed from the support surface 6. According to step 58, the construction container 8 is placed on the support surface 6. According to step 60, the construction container 8 is at least partially filled with a photosensitive fluid 10, such as a photocurable liquid. According to step 62, the construction platform 20 is loaded onto the elevator 16. According to step 64, the control unit 30 operates the vertical movement mechanism 18, the projector 26, and the lateral movement mechanism 28 to fabricate a 3D object. Step 64 of one embodiment is described similarly to method 90 in Figure 10.

[0030] Figure 9 is a flowchart of a method 70 for aligning pixelated image forming tiles 40 according to one embodiment. Method 70 corresponds to step 54 of method 50.

[0031] According to step 72, the control unit 30 operates the lateral movement mechanism 28 to position the projector 26 along the X' and Y' axes and position the first tile 40-1 within the camera field of view (CFV) 42 of the camera 36. According to step 74, the control unit 30 operates the projector 26 to illuminate part or all of the first pixelated tile 40-1 having at least a leading edge 46-1 within the camera field of view 42. According to step 76, the control unit 30 operates the camera 36 to image the position coordinates defined by the leading edge 46-1 of the first tile 40-1.

[0032] According to step 78, the control unit operates the lateral movement mechanism 28 to position the projector along the X' and Y' axes and position the second tile 40-2 within the camera field of view (CVF) 42 of the camera 36. According to step 80, the control unit 30 operates the projector 26 to illuminate part or all of the second pixelated tile 40-2 having at least a trailing edge 48-2 within the camera field of view 42. According to step 82, the control unit operates the camera 36 to image the position coordinates defined by the trailing edge 48-2 of the second tile 40-2.

[0033] If there are no errors, the front edge 46-1 of the first tile 40-1 should be perfectly aligned with the rear edge 48-2 of the second tile 40-2. However, in reality, as shown in Figure 6, there is a positional misalignment in both X' and Y' between the rear edge 48-2 and the front edge 46-1. The control unit 30 calculates the X' and Y' errors of the rear edge 48-2 relative to the front edge 46-1. Using this error, the control unit 30 remaps the movement coordinates of the X' and Y' axes, effectively shifting the rear edge 48-2 of the second tile 40-2 so that it aligns with the front edge 46-1 of the first tile 40-1 in terms of the X' and Y' axes, as shown in Figure 7.

[0034] Figure 10 is a flowchart of a method 90 for producing a 3D article using an apparatus 2 calibrated according to method 70, according to one embodiment. According to step 92, the 3D printing apparatus 2 is provided with a construction container 8 containing a photosensitive fluid 10, such as a photocurable liquid or ink, and a construction platform 20 placed on an elevator 16.

[0035] According to step 94, the control unit 30 operates the vertical movement mechanism 18 to position the lower surface 24 (or later the 3D object 35) of the construction plate 22 on the construction plane 38. According to step 96, the control unit 30 operates the lateral movement mechanism 28 to position the projector 26 for illuminating the first tile 40 (n=1). According to step 98, the control unit 30 operates the projector 26 to selectively illuminate the first tile 40 (n=1). Steps 96 and 98 are repeated a total of N times to selectively illuminate all the tiles required for the first slice m=1.

[0036] Subsequently, for the second slice m=2, the process loops back to step 94. This sequence repeats itself to complete the fabrication of the 3D object. Depending on the geometric shape of the 3D object, the number N of tiles 40 required for a given slice m can vary. Thus, N can be a function of m or N(m).

[0037] This method and apparatus can be used to produce articles having one or more high-resolution features. For example, this method and apparatus can be used to manufacture articles having one or more features with one or more dimensions such as 10 microns or less, 8 microns or less, 6 microns or less, 5 microns or less, 4 microns or less, 3 microns or less, 2 microns or less, 1 micron or less, 0.8 microns or less, or 0.6 microns or less.

[0038] In some embodiments, the present method and apparatus can be used to manufacture articles having one or more features with each of the following transverse dimensions: 10 microns or less, 8 microns or less, 6 microns or less, 5 microns or less, 4 microns or less, 3 microns or less, 2 microns or less, 1 micron or less, 0.8 microns or less, or 0.6 microns or less.

[0039] The specific embodiments and uses described above are for illustrative purposes only and do not preclude modifications and variations that are covered by the technical scope of the following claims.

[0040] While the foregoing refers to certain preferred embodiments, it will be understood that the present invention is not limited thereto. Various modifications can be made to the disclosed embodiments, and it will be apparent to those skilled in the art that such modifications are intended to fall within the technical scope of the present invention.

[0041] All publications, patent applications, and patents referenced herein are incorporated herein by reference in their entirety.

Claims

1. In a method for manufacturing three-dimensional (3D) articles, The aforementioned method, A method comprising operating a 3D printing apparatus, the 3D printing apparatus having a projector configured to selectively irradiate a photosensitive fluid along a horizontal construction plane defined along the X and Y axes, the projector being connected to a lateral movement mechanism configured to scan the projector laterally along each of the X' and Y' axis movement coordinates which are not precisely aligned with the X and Y axes, respectively, and the projector being configured to selectively irradiate an array of adjacent pixelated tiles within the horizontal construction plane, The aforementioned method, To provide a camera having a camera field of view (CFV) in the lateral direction within the aforementioned horizontal construction plane, In order to position the leading edge of the first pixel tile within the camera's field of view, the projector is positioned along the movement coordinates in the X' and Y' axes, Operate the projector to illuminate at least the leading edge of the first pixelated tile, Operating the camera to image the leading edge of the first pixelated tile, The projector is moved parallel along the Y' axis so that the second pixel tile is positioned adjacent to the first pixel tile so that the trailing edge of the second pixel tile is aligned with the leading edge of the first pixel tile, Operate the projector to illuminate at least the trailing edge of the second pixelated tile, Operating the camera to image the trailing edge of the second pixelated tile, To calculate the alignment error of the trailing edge relative to the leading edge along the X' and Y' axes, A method comprising remapping the X'-axis and Y'-axis movement coordinates so that the front edge of the first pixel tile is aligned with the rear edge of the second pixel tile.

2. The method according to claim 1, wherein operating the projector comprises projecting the first pixel tile and the second pixel tile upward onto the horizontal construction plane.

3. The 3D printing apparatus has a support surface that at least partially surrounds the horizontal construction plane in the lateral direction, The method according to claim 1 or 2, wherein providing the camera involves stacking an image capturing plate having the camera facing downward on the support surface.

4. The 3D printing apparatus has a support surface that at least partially surrounds the horizontal construction plane in the lateral direction, The method according to claim 1 or 2, further comprising loading a construction container onto the support surface, and loading the photosensitive fluid into the construction container either before or after loading the construction container onto the support surface.

5. The 3D printing apparatus has an elevator connected to a vertical movement mechanism, The method according to claim 4, further comprising loading a construction platform having a construction plate onto the elevator.

6. The construction container has a transparent member that provides a lower limit for the photosensitive fluid, The method according to claim 4 or 5, further comprising operating the vertical movement mechanism, the lateral movement mechanism, and the projector to produce the 3D article with an array of selectively cured layers formed on the horizontal construction plane above the transparent member.

7. For each layer of the array of selectively cured layers, the method is as follows: The vertical movement mechanism is operated to position the lower surface of the horizontal construction plane or a previous layer of the 3D object on the horizontal construction plane. The method according to any one of claims 1 to 6, further comprising operating the lateral movement mechanism and the projector to illuminate the array of pixelated tiles on the horizontal construction plane in order to selectively harden the continuous tiles aligned along the layers, the leading edge and the trailing edge of the array of selectively hardened layers.

8. In a 3D printing device, The 3D printing apparatus comprises a projector, a photosensitive fluid, a camera, a lateral movement mechanism, and a processor. The projector is configured to selectively irradiate a photosensitive fluid along a horizontal construction plane defined along the X and Y axes. The projector is connected to a lateral movement mechanism configured to scan the projector laterally along the respective X' and Y' axis movement coordinates, which are not precisely aligned. The projector is configured to selectively illuminate an array of adjacent pixelated tiles within the horizontal construction plane. The camera has a camera field of view that is located laterally within the horizontal construction plane. The processor is configured to control the projector, the camera, and the lateral movement mechanism, respectively. The 3D printing apparatus is The projector is positioned along the X' and Y' axis movement coordinates so that the leading edge of the first pixel tile is placed within the camera's field of view. The projector is operated to illuminate at least the leading edge of the first pixelated tile, The camera is operated to image the leading edge of the first pixelated tile, The projector is moved parallel along the Y' axis so that the front edge of the first pixel tile and the rear edge of the second pixel tile are aligned, and the second pixel tile is positioned adjacent to the first pixel tile. The projector is operated to illuminate at least the trailing edge of the second pixelated tile, The camera is operated to image the trailing edge of the second pixelated tile, The alignment error of the trailing edge relative to the leading edge along the X' and Y' axes is calculated. A 3D printing apparatus configured to remap the movement coordinates in the X' and Y' axes so that the front edge of the first pixel tile is aligned with the rear edge of the second pixel tile.

9. The 3D printing apparatus according to claim 8, further configured to project the first pixelated tile and the second pixelated tile upward onto the horizontal construction plane.

10. The 3D printing apparatus according to claim 8 or 9, further comprising a support surface that at least partially surrounds the horizontal construction plane in a lateral direction, and an image capturing plate on the support surface, wherein the image capturing plate has the camera facing downward.

11. The 3D printing apparatus according to claim 8 or 9, further comprising a support surface that at least partially surrounds the horizontal construction plane in a lateral direction, and a construction container located on the support surface, wherein the construction container contains the photosensitive fluid.

12. The 3D printing apparatus according to claim 11, further comprising an elevator connected to a vertical movement mechanism and a construction platform on the elevator, wherein the construction platform comprises a construction plate.

13. The 3D printing apparatus according to claim 11 or 12, wherein the construction container has a transparent member that provides a lower limit for the photosensitive fluid, and the 3D printing apparatus is further configured to operate the vertical movement mechanism, the lateral movement mechanism and the projector to produce the 3D article having an array of selectively cured layers formed on the horizontal construction plane above the transparent member.

14. The 3D printing apparatus according to any one of claims 8 to 13, wherein for each layer of the array of selectively cured layers, the 3D printing apparatus is further configured to operate the lateral movement mechanism and the projector to illuminate the array of pixelated tiles on the horizontal construction plane in order to selectively cure the layers of the array of selectively cured layers, which are continuous tiles aligned along the leading and trailing edges, by operating the vertical movement mechanism to position the lower surface of the construction plate or a previous layer of the 3D article on the horizontal construction plane.

Images