System and method for performing optically calibrated large-area microstereolithography

Abstract

Provided herein is a system for producing a product. The system generally includes a large area micro-stereolithography system, an optical imaging system, and a controller in communication with the large area micro-stereolithography system and the optical imaging system. The large area micro-stereolithography system is capable of producing a product by photopolymerizing successive layers of a curable resin at a build surface. The controller is capable of directing the optical imaging system to obtain one or more optical images of a product or a reference component located at the build surface, and adjusting parameters associated with the large area micro-stereolithography system based on the one or more images.

Description

[Technical Field]

[0001] This application is a non-provisional application claiming the benefits of U.S. Provisional Application No. 63 / 179,984, filed on 26 April 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The subject matter described herein relates to an optically calibrated large-area microstereolithography system for manufacturing products, and related apparatus and methods. This microstereolithography system is useful for 3D printing of parts, among other applications. [Background technology]

[0003] The concept of microstereolithography is used in the rapid prototyping and small-scale production of plastic components and other complex 3D objects. An object is produced in a fluid medium by selective curing of the medium by focusing a radiation beam onto the surface of the medium or a nearby build or print surface, or by selective curing of the medium through volumetric exposure, delivering a desired energy dose to different parts of the medium. A 3D model (e.g., generated using CAD software, 3D scanning, or other means) is subdivided into 2D slices, each of which can be subdivided into multiple regions. A projection device can then expose the image of each region onto the corresponding region of the build surface. This allows for extremely high-resolution exposure with voxels as small as tens of microns over areas hundreds of millimeters or larger. The exposed layers are then lowered into the medium using an elevator system, allowing new layers to be exposed within the now empty build surface. Thus, large forms can be constructed quickly, reliably, and reproducibly until the finished 3D object is manufactured. Such a principle is described, for example, in Moran's U.S. Patent Application Publication No. 2016 / 0303797, which we will refer to here as if it were fully described.

[0004] However, such microstereolithography systems have numerous drawbacks that can degrade the system's resolution and / or beam registration, including undesirable variations in beam focus and intensity across the build plane, and others, resulting in lower quality parts. Therefore, there has been a long-standing need for improved microstereolithography systems that address the aforementioned and other concerns.

[0005] The information contained herein, including any references cited herein and their descriptions or discussions, is included solely for technical reference purposes and should not be considered as subject matter that restricts the scope of this disclosure. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Application Publication No. 2016 / 0303797 [Overview of the Initiative]

[0007] An optically calibrated, large-area microstereolithography (OCLAuSL) system is disclosed, comprising an optical system, a spatial light modulator (SLM), a beam delivery system, a curable resin tank, an elevator system within the tank, and an optical imaging system. A 3D model of an object (e.g., a CAD model or 3D image) is subdivided into slices and slice regions. Each slice region is projected onto a corresponding region of the build surface or print surface near the surface of the curable resin tank until the desired voxels across the entire build surface are exposed, thus crosslinking the exposed regions into a solid polymer. The elevator then descends to bring new resin to the build surface so that a new layer can be exposed. New layers are produced until a finished 3D object is created. Because the build surface or print surface is subdivided into multiple regions, the resolution of each exposure can be very high (e.g., voxel size of tens of microns or less), while the build surface can potentially be very large (e.g., hundreds of millimeters or more). An optical imaging system is used to image the build surface and calibrate the optics of the microstereolithography system, thus ensuring consistent registration, exposure, and image resolution across the entire build surface. This process is not limited to top-down printing. The build platform can also be raised for each subsequent layer, and the image can be projected upward into the chamber through a window.

[0008] The optically calibrated microstereolithography system disclosed herein is useful, in part, for 3D printing of medically useful objects (including, but not limited to, vascular systems of artificial human organs).

[0009] This summary is provided to introduce, in a simplified form, some of the concepts that will be further described in the detailed explanation below. This summary is not intended to identify any major or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. A more extensive presentation of the features, details, usefulness, and advantages of the optically calibrated microstereolithography system as defined in the claims is provided in the descriptions of the various embodiments of this disclosure below and is shown in the accompanying drawings. [Brief explanation of the drawing]

[0010] Exemplary embodiments of this disclosure will be described with reference to the accompanying drawings, including the following: [Figure 1] This is a schematic diagram of at least a portion of an example of an optically calibrated large-area microstereolithography (OCLAuSL) system according to at least one embodiment of the present disclosure. [Figure 2] This is a schematic diagram of at least a portion of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 3] A flowchart of an example of the OCLAuSL method according to at least one embodiment of this disclosure is shown. [Figure 4] This is a schematic diagram of at least a portion of the build surface of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 5] This is a schematic diagram of at least a portion of the build surface of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 6] This is a schematic side cross-sectional view of at least a portion of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 7a] This is a perspective view of at least a portion of the build surface of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 7b]This is a perspective view of at least a portion of a curable resin tank in an example of an OCLAuSL system according to at least one embodiment of the present disclosure. [Figure 8] This is a schematic diagram of a processor circuit according to an embodiment of the present disclosure. [Figure 9] This is a schematic diagram illustrating an example of an optical imaging system physically separated from the optical system, SLM system, and beam delivery system of an optically calibrated large-area microstereolithography system according to embodiments of the present disclosure. [Figure 10] This invention presents an example of an optically calibrated large-area microstereolithography system that uses a beam splitter or dichroic to perform large-area microstereolithography and optical imaging through a common optical element. [Figure 11] An exemplary helical scanning pattern according to an embodiment of the present disclosure is shown. [Modes for carrying out the invention]

[0011] According to at least one embodiment of the present disclosure, an optically calibrated large-area microstereolithography system is provided that can be used for the rapid manufacturing of complex macroscopic three-dimensional components having microscopic shapes. The system uses a spatial light modulator (SLM), such as a liquid crystal display (LCD) screen or a digital micromirror display (DMD), in conjunction with a scanning optical projection system to create large, detailed objects through microstereolithography. A 3D computer model is subdivided into multiple slices, each slice is subdivided into multiple regions, each region is communicated to the SLM to form an image. The SLM image is then projected onto a photosensitive liquid (e.g., resin) that is crosslinked or otherwise cured as a result of radiation exposure. This projection is performed using a scanning optical system that can direct the SLM image to different build regions of a build surface or print surface that are much larger than the SLM image itself. The imaging of new model regions on the SLM is coordinated with an optical system so that each image is directed to the appropriate part of the build surface, and the model region being imaged and the projected position on the build surface change either discretely (e.g., flash-and-move imaging) or continuously. Using beam-directing optics, the projection is moved to a new position on the build surface as the SLM pattern is updated, creating a large continuous image in the photosensitive fluid that is much larger than a single SLM image. This makes it possible to manufacture parts or products with very large, yet small, build sizes. Thus, one microstereolithography system covers a considerable area. However, to manufacture even larger items, multiple microstereolithography systems can be combined together so that their build surfaces cover an even larger area. By coordinating the SLM images and scanning optics of two or more microstereolithography systems, a single processor or controller can generate the required pattern across the combined build surfaces, which can be increased to any size by including further microstereolithography systems.

[0012] The OCLAuSL system also includes an optical imaging system (which may be coaxial with the beam delivery system that projects SLM images). The optical imaging system can be used to image the build surface. More specifically, the optical imaging system can image items on the build surface, such as the product being built, or a reference component or test pattern, or a mirror or other reference target with known optical properties. The CPU, processor, or controller can then analyze one or more images of the build surface to make adjustments to parameters of the optical system, such as brightness or focus, or parameters of the SLM, such as the grayscale properties of the SLM image, or parameters of the beam delivery system, such as focus and image positioning. Thus, the microstereolithography system can be calibrated using the optical imaging system either in real time or near real time before or during the manufacturing of a new product.

[0013] As with other stereolithography systems, the volumetric rate of polymerization (the volume that changes from liquid to solid per unit time) can be determined, at least in part, by the critical energy of the resin and the total power of the light used for polymerization. For example, some embodiments of the systems described herein may be capable of polymerizing the resin at a rate of several liters per hour, although faster and slower rates are also intended.

[0014] The OCLAuSL system, apparatus, and method can rapidly manufacture large items (e.g., tens, hundreds, or thousands of millimeters in size, or other sizes both larger and smaller) with consistent high-resolution molding across the area or volume of the product (e.g., voxel size of tens of microns or less, comparable to the scale of human cells). For example, the OCLAuSL system, apparatus, and method can manufacture items with volumes of at least approximately 0.1 liters (L), 0.2 L, 0.3 L, 0.4 L, 0.5 L, 0.6 L, 0.7 L, 0.8 L, 0.9 L, 1 L, and 2 L or more in no more than approximately 24 hours (h), 18 h, 16 h, 14 h, 12 h, 10 h, 8 h, 7 h, 6 h, 5 h, 4 h, 3 h, 2 h, and 1 h. The OCLAuSL system, apparatus, and method can manufacture items with volumes of no more than approximately 2L, 1L, 0.9L, 0.8L, 0.7L, 0.6L, 0.5L, 0.4L, 0.3L, 0.2L, and 0.1L in no more than approximately 24h, 18h, 16h, 14h, 12h, 10h, 8h, 7h, 6h, 5h, 4h, 3h, 2h, and 1h. The OCLAuSL system, apparatus, and method can manufacture items with volumes within the range defined by any two of the aforementioned values ​​in a time range defined by any two of the aforementioned values. In some cases, the manufactured items can be used as finished products. In other cases, the manufactured items can subsequently be used as molds or masters for casting, blow molding, injection molding, thermoforming, and other manufacturing processes for polymer, metal, or ceramic objects.

[0015] Since the manufactured object or product is ultimately constructed of voxels (e.g., 3D pixels), its structure may appear "pixelated" when viewed at a sufficiently fine scale. However, one advantage of this disclosure is that such pixelation can occur at a scale too fine to be perceived by the human eye, and at a scale comparable to the scale of tissue layers composed of human cells (which are also "pixelated" in the sense that they are constructed from indivisible subunits).

[0016] This ability to consistently produce finely detailed items with large volume or cross-sectional area distinguishes the OCLAuSL system, apparatus, and method from other technologies, facilitating not only the rapid production of prototypes but also the rapid production of finished, customized, small-batch products for individual customers. The photocurable medium may also contain particles of metal, ceramic, or other materials (e.g., wood), enabling the production of composite parts and / or the removal of polymers and the sintering of (e.g.) metal or ceramic components, thereby enabling the production of pure metal or ceramic parts.

[0017] For the purpose of facilitating understanding of the principles of this disclosure, embodiments shown in the drawings will be referenced and described here using specific language. However, no limitation on the scope of this disclosure is intended to be understood. Any modifications and further changes to the described devices, systems, and methods, as well as any further applications of the principles of this disclosure, as commonly conceived by those skilled in the art, are entirely contemplated and included within this disclosure. In particular, it is entirely contemplated that features, components, and / or steps described in relation to one embodiment may be combined with features, components, and / or steps described in relation to other embodiments of this disclosure. However, for the sake of brevity, numerous iterations of such combinations will not be described separately.

[0018] These descriptions are provided for illustrative purposes only and should not be considered to limit the scope of optically calibrated large-area microstereolithography systems. Certain features may be added, removed, or modified without departing from the subject matter of the claims.

[0019] Figure 1 is a schematic diagram of at least a portion of an example of an optically calibrated large-area microstereolithography (OCLAuSL) system 100 according to at least one embodiment of the present disclosure. The OCLAuSL system 100 includes an OCLAuSL beam unit 110 that projects an image beam 185 onto a build surface 190.

[0020] The OCLAuSL beam unit 110 includes an optical system 112 that generates a light beam 113, which is projected through or onto a spatial light modulation (SLM) system 114 that generates an image. The SLM system may be, for example, a liquid crystal display (LCD) screen through which the beam 113 passes, or a digital micromirror display (DMD) that the beam 113 reflects, or one or more rotating disks having apertures (such as in a rotating disk confocal microscopy), or other types of spatial light modulators 114 that serve the purpose of generating modulated image light 115 from the light beam 113. The SLM system may have resolutions of, for example, 640 × 480 pixels, 1024 × 768 pixels, 1920 × 1080 pixels, 2716 × 1528 pixels, or other resolutions, both larger and smaller. In some embodiments, the optical system 112 and the SLM system 114 may be combined into a single system. For example, the modulated image light 115 may be generated by directly imaging an array of light sources, such as a micro-LED array. Regardless of how it is generated, the modulated image light 115 is then passed through a beam delivery system 116 that projects the image beam 185 onto the build surface 190.

[0021] The OCLAuSL system 100 also includes a controller, central processing unit (CPU), or processor 170 capable of controlling or sending commands to the optical system 112, the SLM system 114, and the beam delivery system 116. In some embodiments, one or more of the optical system 112, the SLM system 114, or the beam delivery system 116 may include its own controller 170, and in some of those embodiments, these controllers 170 communicate with each other and / or with separate controllers 170.

[0022] The controller 170 contains, or receives, a 3D model 120 of the desired product. The controller then divides the 3D model 120 into multiple 2D slices 130, or receives multiple 2D slices 130 from another source. For example, the 3D model may contain at least approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9 It can be divided into 000, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 200000, 300000, 400000, 500000, 600000, 700000, 800000, 900000, and over 1 million slices. 3D models typically have a maximum of approximately 1 million, 900,000, 800,000, 700,000, 600,000, 500,000, 400,000, 300,000, 200,000, 100,000, 90,000, 80,000, 70,000, 60,000, 50,000, 40,000, 30,000, 20,000, 10,000, 9 It can be divided into 000, 8000, 7000, 6000, 5000, 4000, 3000, 2000, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1. The 3D model can be divided into a number of slices within the range determined by any two of the aforementioned values. Each slice defines a planar cross-section through the object or product being constructed and can be stored individually (for example, as a series of BMP, JPEG, or other image files). Then, for each individual slice 140, the controller subdivides the 2D slice 140 into multiple regions 150, or receives multiple regions 150 from another source. In one example, some slices may have only one region, but if the regions do not overlap, there may be hundreds of regions, and if the regions do overlap, there may be millions of regions within each slice. Other configurations are also possible and are within the scope of this disclosure.

[0023] These regions can also be stored as individual image files in any desired format. The controller then selects the current region 160 from a plurality of regions 150 and sends information about the current region 160 to the SLM system 114, which generates a modulated image light 115 from the beam 113, which may be an image of the currently selected region 160 of the current 2D slice 140 of the 3D model 120 of the desired object or product. The modulated image light 115 is then passed through the beam delivery system 116, which may, for example, magnify and focus the modulated image light 115 into a projected image beam 185 containing images of the corresponding parts of the 3D model 120 and therefore the corresponding parts of the desired product. The projected image beam 185 intersects the build plane 190 so that the image generated by the SLM 114 is focused onto the build plane 190. The projected image beam 185 may contain a monochrome (e.g., black and white) image, a grayscale image, or a combination thereof. Color images may also be used, but the color does not need to affect the curing of the photosensitive resin. This modulation of the projected image beam 185 is sometimes called "dynamic masking".

[0024] The build surface 190 is subdivided into multiple build regions 195, each corresponding to one of several regions 150 of the currently selected 2D slice 140, specifically region 160. The currently illuminated build region 197 is exposed by the projection image beam 185, allowing the photocurable resin within that portion of the build surface to be exposed and solidified by the bright portion of the projection image beam 185, while the dark portion remains liquid, as will be described later. The selection of the image region 160 and the build region 197 may be discrete (e.g., flash-and-move exposure) or continuous. In some examples, the exposure rate can be at least 10 Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, 100 Hz, 110 Hz, 120 Hz or higher. In some embodiments, the exposure rate can be no more than approximately 120Hz, 110Hz, 100Hz, 90Hz, 80Hz, 70Hz, 60Hz, 50Hz, 40Hz, 30Hz, 20Hz, or 10Hz. In some embodiments, the exposure rate is within the range defined by any two of the aforementioned values. In some examples, exposure may be at a spatial light modulator modulation rate such as 10-20kHz, or at a video frame rate of 60Hz, but other rates, both higher and lower, may be used instead or in addition.

[0025] In some embodiments, the system generates each region within a time of at least approximately 10 microseconds (μs), 20 μs, 30 μs, 40 μs, 50 μs, 60 μs, 70 μs, 80 μs, 90 μs, 100 μs, 200 μs, 300 μs, 400 μs, 500 μs, 600 μs, 700 μs, 800 μs, 900 μs, 1 millisecond (ms), 2 ms, 3 ms, 4 ms, 5 ms, 6 ms, 7 ms, 8 ms, 9 ms, 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms, 100 ms, 200 ms, 300 ms, 400 ms, 500 ms, 600 ms, 700 ms, 800 ms, 900 ms, or 1,000 ms or more. In some embodiments, the system generates each region within a time of no more than approximately 1,000 ms, 900 ms, 800 ms, 700 ms, 600 ms, 500 ms, 400 ms, 300 ms, 200 ms, 100 ms, 90 ms, 80 ms, 70 ms, 60 ms, 50 ms, 40 ms, 30 ms, 20 ms, 10 ms, 9 ms, 8 ms, 7 ms, 6 ms, 5 ms, 4 ms, 3 ms, 2 ms, 1 ms, 900 μs, 800 μs, 700 μs, 600 μs, 500 μs, 400 μs, 300 μs, 200 μs, 100 μs, 90 μs, 80 μs, 70 μs, 60 μs, 50 μs, 40 μs, 30 μs, 20 μs, and 10 μs. In some embodiments, the system generates each region for a time period defined by any two of the aforementioned values.

[0026] While sequentially selecting different regions 160 from multiple regions 150 of the current 2D slice, the controller 170 generates corresponding images using the SLM 114 and instructs the beam delivery system 116 to expose them onto different selected build regions 197 from multiple build regions 195 of the build surface 190. Thus, a complete 2D slice of the desired product can be created within the build surface 190. The completed 3D product can be manufactured by lowering the product into a photocurable resin tank using an elevator system, as described later, and sequentially exposing each of the multiple 2D slices 130 140.

[0027] The OCLAuSL beam unit 110 of the OCLAuSL system 100 also includes an optical imaging system 118 under the control of a controller 170. The optical imaging system is capable of imaging at least a portion of the build surface 190. In some embodiments, the optical imaging system 118 is capable of imaging the entire build surface 190 in either a single image or sequential images, whether discrete or continuous scanning. In particular, the optical imaging system 118 can be used to image items on the build surface, such as the product being built, or a reference component or test pattern, or a mirror or other reference target with known optical properties. The controller 170 can then analyze one or more images of the build surface to make adjustments to the parameters of the optical system 112 (e.g., brightness, focus, collimation, alignment), or the parameters of the SLM system 114 (e.g., image contrast, brightness, grayscale characteristics), or the parameters of the beam delivery system 116 (e.g., focus, alignment, image positioning). Thus, the OCLAuSL system 100 can be calibrated using an optical imaging system either in real time or near real time before or during the manufacturing of a new product.

[0028] In some embodiments, the controller 170 can process one or more optical images of the product to determine one or more characteristics associated with the product. These characteristics can then be compared to desired characteristics of the product, and various parameters related to the large-area microstereolithography system can be adjusted based on the difference between the characteristics determined from the one or more optical images and the desired characteristics. For example, the controller 170 may process one or more optical images to determine areas of the product where the resin has cured, and to what extent the resin has cured. The controller may process one or more optical images to determine areas of the product where the resin has not cured. These areas can then be analyzed to determine whether the areas where the resin has cured correspond to areas where the resin was intended to cure, and whether the degree of curing corresponds to the intended degree of curing. The areas may also be analyzed to determine whether the areas where the resin has not cured correspond to areas where the resin was not intended to cure. If there is a difference between the measured curing level and the intended curing level, parameters related to the large-area microstereolithography system can be adjusted to reduce this difference. The parameters may be the intensity of the illumination light (e.g., light beam 113) emitted by the large-area microstereolithography system, the focal point of the illumination light (e.g., modulated image light 115 or projection image beam 185), or the frequency of the illumination light. The parameters may be adjusted for the large-area microstereolithography system or product as a whole. Alternatively, or in combination, the parameters may be adjusted on a pixel-by-pixel basis by adjusting the transmittance of the corresponding pixels of the SLM system 114.

[0029] As another example, the controller 170 may process one or more optical images to determine the physical or chemical properties of the product. The physical or chemical properties may be the stiffness or modulus of the product. The controller may process one or more optical images to determine the physical or chemical properties of any given region of the product. The controller may then analyze the physical or chemical properties to determine whether they match the intended physical or chemical properties. If there is a difference between the measured physical or chemical properties and the intended physical or chemical properties, the parameters may be adjusted to reduce this difference, as described above.

[0030] The controller 170 can process one or more optical images in a variety of ways. For example, the controller 170 can apply one or more computer vision techniques such as centroid detection, edge detection, thresholding, blob detection, or blob area determination.

[0031] In some embodiments, the controller may process one or more optical images of reference components located on the build surface instead of processing one or more optical images of the product itself. For example, the optical imaging system 118 may be able to acquire one or more optical images of a substantially uniform light-emitting surface located substantially close to the build surface. A substantially uniform light-emitting surface may emit light such that the relative emission of substantially all points on its surface is known (e.g., substantially all points may emit the same amount of light). The controller 170 may be able to direct illumination light from the large-area microstereolithography system to illuminate the substantially uniform light-emitting surface and instruct the optical imaging system 118 to acquire one or more images of the substantially uniform light-emitting surface. The controller 170 may also be able to direct illumination light from an illumination source not associated with the large-area microstereolithography system to illuminate the substantially uniform light-emitting surface and instruct the optical imaging system 118 to acquire one or more images of the substantially uniform light-emitting surface. The controller may then analyze one or more images and calibrate the large-area microstereolithography system based on one or more images. One or more images may be analyzed to determine the response of each pixel in the optical imaging system 118. If one or more pixels in the optical imaging system 118 produce a response substantially different from the uniform signal expected across substantially all pixels, the parameters of the large-area microstereolithography system may be modified to obtain a uniform response across substantially all pixels. For example, the parameters of the optical imaging system may be modified to obtain a uniform response across substantially all pixels. This procedure may be performed before, during, or after production of the product using the large-area microstereolithography system.

[0032] In some embodiments, the system 100 further includes a test substrate (not shown in Figure 1). In some embodiments, the test substrate is positioned substantially close to the printed surface 190. For example, in some embodiments, the test substrate is positioned at least about 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm or more from the printed surface 190. In some embodiments, the test substrate is positioned at least about 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm or less from the printed surface 190. In some embodiments, the test substrate is positioned at a distance from the printed surface 190 within a range determined by any two of the aforementioned values. In some embodiments, the controller 170 can further direct illumination light from the large-area microstereolithography system to illuminate the test substrate. In some embodiments, the controller 170 can further instruct the optical imaging system to acquire one or more test images of the test substrate. Thus, the contrast from the test substrate can be imaged. The controller can then analyze one or more test images and calibrate the large-area microstereolithography system based on the test images.

[0033] Such a test substrate may have optical features placed in precisely known positions. When one of these optical features enters the field of view (FOV) of the optical imaging system 118, such information can be used to accurately determine the optical alignment of the optical system 112, the SLM system 114, or the beam delivery system 116, or to accurately determine the mechanical alignment of the constructed product. Thus, misalignment can be compensated for.

[0034] In some embodiments, the optical imaging system 118 and the beam delivery system 116 may share at least one common lens or aperture 180, but as can be understood by those skilled in the art, in other embodiments, each may include its own separate lens and aperture. In some cases, the optical imaging system 118 may be physically separated from the optical system 112, SLM 114, and beam delivery system 116, as shown in Figure 9. For example, the optical imaging system 118 may be housed in a separate housing and / or positioned in close proximity to the build surface 190.

[0035] In some embodiments, the optical imaging system 118 is positioned substantially close to the build surface 190. For example, the optical imaging system 118 may be positioned at least about 1 centimeter (cm), 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, or 100 cm or more from the build surface 190. The optical imaging system 118 may be positioned at least about 100 cm, 90 cm, 80 cm, 70 cm, 60 cm, 50 cm, 40 cm, 30 cm, 20 cm, 10 cm, 9 cm, 8 cm, 7 cm, 6 cm, 5 cm, 4 cm, 3 cm, 2 cm, or 1 cm or less from the build surface 190. The optical imaging system 118 may be positioned at a distance from the build surface 190 within a range determined by any two of the aforementioned values.

[0036] Before continuing, it should be noted that the examples above are provided for illustrative purposes only and are not intended to be limiting. Other devices and / or device configurations may be used to perform the operations described herein.

[0037] Figure 2 is a schematic diagram of at least a portion of an example of an OCLAuSL system 100 according to at least one embodiment of the present disclosure. The OCLAuSL system 100 includes an optical system 112, a spatial light modulation (SLM) system 114, a beam delivery system 116, and an optical imaging system 118. In some embodiments, the beam delivery system 116 and the optical imaging system 118 may share a common lens or aperture 180, in other embodiments not. In some embodiments, the common lens or aperture is or includes a beam splitter.

[0038] The beam delivery system 116 projects an image beam 185 onto a selected build area 197. In one example, the projected image beam 185 includes all wavelengths of light generated by the optical system 112. In another example, the projected image beam includes only selected wavelengths of light generated by the optical system 112 (e.g., chemical wavelengths best suited for curing the photosensitive resin in the build surface).

[0039] The optical imaging system is capable of imaging a selected build region. In some embodiments, the optical imaging system images the selected build region 197 using reflected light from a projected image beam. In other embodiments, the optical imaging system illuminates the selected build region 197 with a different portion of the light generated by the optical system (for example, a non-chemical wavelength that is less suitable for curing the photosensitive resin or is best suited for imaging selected features within the build surface).

[0040] The optical system 112 may include, for example, a beam generator 210 and a tuning optical system 220. The beam generator 210 may be, or include, other photogenerating components known in the art, including, for example, light-emitting diodes (LEDs), superluminescent diodes (SLDs), lasers, halogen bulbs or other incandescent light sources, xenon lamps or other electric arc sources, limelights or other candoluminescent sources, or combinations thereof. In some embodiments, the light may be conditioned to include Kohler illumination. The beam generator 210 may generate light of a single wavelength, a narrow range of wavelengths, or a wide range of wavelengths. The emitted wavelengths may include infrared, visible, and ultraviolet wavelengths. The optical system 112 may also include a tuning optical system 220. The adjustment optical system 220 may include, for example, a collimating lens or other collimating optical system (e.g., for focusing the beam), a beam homogenizer, a beam expander (for matching the beam size to the size of the SLM 114), one or more filters (for transmitting light of a specific wavelength, such as a chemical ray wavelength capable of initiating a photochemical reaction, while reflecting or absorbing other wavelengths, such as a non-chemical ray wavelength), one or more mirrors, one or more lenses, one or more beam splitters, one or more pupils, one or more shutters, one or more beam expanders or beam reducers, and / or other optical systems known in the art required to direct the generated light towards the SLM system 114 and / or to illuminate a selected build area 197 for an optical imaging system. The adjustment optical system 220 may also include one or more sensors capable of monitoring the state of the beam (e.g., brightness, alignment, etc.).

[0041] The beam delivery system 116 may include, for example, a beam steering system 230 and a beam delivery optical system 240. The beam steering system 230 may be, or include, a steerable mirror such as a galvanometer mirror or a rotating polygon mirror. In one example, the beam steering system is a micro-actuated mirror with an accuracy of 10 microns or better, configured to deliver SLM images to the appropriate location in the resin tank under the control of a controller 170 (see Figure 1). In some embodiments, the beam steering system has one or more galvanometer mirrors that are steerable discretely or continuously in two dimensions and may be operated by one or more stepper motors or servo motors. In some embodiments, the beam steering system has one or more rotating polygon mirrors that are steerable discretely in one dimension and may be operated by one or more motors. A beam steering system having one or more rotating polygon mirrors can increase the rate at which different build areas on the build surface are illuminated. The rotational speed of such a rotating polygon mirror may be proportional to the rate at which different build areas on the build surface are illuminated. Compared to a galvanometer, which may need to change its direction of travel during beam steering, a rotating polygon mirror can avoid having to change its direction of travel and therefore can rotate very quickly, resulting in a substantial increase in the speed at which different build areas on the build surface are illuminated.

[0042] The beam delivery system 116 may also include a beam delivery optical system 240. The beam delivery optical system 240 may include, for example, one or more mirrors, one or more beam expanders or beam reducers (e.g., to match the size of the projected image beam 185 to the size of the selected build region 197), one or more focusing lenses (e.g., to ensure that the focal plane of the projected image beam 185 is coplanar with the selected build region 197), one or more collimating lenses or other collimating optical systems, one or more apertures, one or more scanning lenses (e.g., flat-field scanning lenses), and / or other optical systems known in the art required to deliver the projected image beam 185 from the beam steering system 230 to the selected build region 197. As described later, the build surface is formed on the top layer of the bath of photocurable material, exposing or curing a desired pattern within the material.

[0043] Köhler illumination may be particularly useful because it can prevent images of the optical system 112, beam generator 210, adjustment optics 220, SLM system 114, beam delivery system 116, beam steering system 230, beam delivery optics 240, or lenses or apertures 180 from appearing within the build plane 190. Köhler illumination can be generated by defocusing the light emitted by the beam generator 210.

[0044] The optical imaging system 118 may include, for example, an image sensor 250 such as a charge-coupled device (CCD) array or a complementary metal-oxide-semiconductor (CMOS) camera, and an imaging optical system 260. The imaging optical system 260 may include lenses, mirrors, beam splitters, shutters, pupils, and other optical components as understood by those skilled in the art, which perform the function of delivering an accurate image of the build surface 190 or the current build region 197 to the image sensor 250 so that the accurate image can be captured by the image sensor 250 and analyzed (for example by the controller 170 in Figure 1). Depending on the implementation, the optical imaging system 118 may be a bright-field imaging system, a fluorescence imaging system, a reflectance imaging system, a scattering imaging system, a refractive index difference imaging system, a luminescence imaging system, a polarization analysis imaging system, a differential interference contrast imaging system, a phase-contrast microscopy imaging system, a Raman scattering imaging system, a spectral imaging system, an optical coherence tomography (OCT) imaging system, an interference imaging system, or other types of imaging systems known in the art. In some embodiments, the optical imaging system 118 may be replaced by, or include, a non-optical imaging system 118, such as an ultrasonic imaging system or a photoacoustic imaging system. In these cases, as technically understood, the image sensor 250 may be or include a suitable image sensor for the selected imaging modality (e.g., an ultrasonic or photoacoustic transducer array), and the imaging optical system 260 may include or be replaced by a suitable beam adjustment system 260 for the selected imaging modality (e.g., a microbeam former, an A / D converter, etc.).

[0045] In some embodiments, the ultrasonic imaging system or photoacoustic imaging system may be capable of detecting pressure waves. In some embodiments, the ultrasonic imaging system or photoacoustic imaging system is positioned substantially close to the build surface 190. For example, in some embodiments, the ultrasonic imaging system or photoacoustic imaging system is positioned within at least about 0.1 cm, 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, and 10 cm or more of the build surface 190. In some embodiments, the ultrasonic imaging system or photoacoustic imaging system is positioned at least about 10 cm, 9 cm, 8 cm, 7 cm, 6 cm, 5 cm, 4 cm, 3 cm, 2 cm, 1 cm, 0.9 cm, 0.8 cm, 0.7 cm, 0.6 cm, 0.5 cm, 0.4 cm, 0.3 cm, 0.2 cm, and 0.1 cm or less of the build surface 190. In some embodiments, the ultrasonic imaging system or photoacoustic imaging system is positioned at a distance from the build surface 190 within a range determined by any two of the aforementioned values. The ultrasonic imaging system or photoacoustic imaging system may be capable of detecting changes in the propagation of pressure waves transmitted through the product constructed on the build surface 190. Such changes may depend on the mechanical properties of the product, such as the elastic modulus of the product. Thus, the ultrasonic imaging system or photoacoustic imaging system may be capable of providing information about the elastic modulus of the product. Using such information, as described herein, one or more parameters related to the large-area microstereolithography system can be adjusted.

[0046] In some embodiments, the optical imaging system 118 may be capable of directing optical imaging light onto the build surface 190. In some embodiments, the optical imaging light may have a light intensity or irradiance that is high enough to produce an image of the build surface 190, but low enough to avoid polymerizing the resin located on the build surface 190. For example, in some embodiments, the optical imaging light may have at least about 1 microwatt / cm². 2(μW / cm 2 ), 2 μW / cm 2 , 3 μW / cm 2 , 4 μW / cm 2 , 5 μW / cm 2 , 6 μW / cm 2 , 7 μW / cm 2 , 8 μW / cm 2 , 9 μW / cm 2 , 10 μW / cm 2 , 60 μW / cm 2 , 70 μW / cm 2 , 80 μW / cm 2 , 90 μW / cm 2 , 100 μW / cm 2 , 200 μW / cm 2 , 300 μW / cm 2 , 400 μW / cm 2 , 500 μW / cm 2 , 600 μW / cm 2 , 700 μW / cm 2 , 800 μW / cm 2 , 900 μW / cm 2 , 1000 μW / cm 2 has the above irradiance. In some embodiments, the optical imaging light has an intensity of at most about 1000 μW / cm 2 , 900 μW / cm 2 , 800 μW / cm 2 , 700 μW / cm 2 , 600 μW / cm 2 , 500 μW / cm 2 , 400 μW / cm 2 , 300 μW / cm 2 , 200 μW / cm 2 , 100 μW / cm 2 , 90 μW / cm 2 , 80 μW / cm 2 , 70 μW / cm 2 , 60 μW / cm 2 , 50 μW / cm 2 , 40 μW / cm 2 , 30 μW / cm 2 , 20 μW / cm 2 , 10 μW / cm 2 , 9 μW / cm 2 , 8 μW / cm 2 , 7 μW / cm2 , 6 μW / cm 2 5 μW / cm² 2 , 4 μW / cm 2 , 3 μW / cm 2 , 2 μW / cm 2 , 1 μW / cm 2 The following irradiances are observed. In some embodiments, the optical imaging light has an irradiance within a range determined by any two of the aforementioned values.

[0047] In some embodiments, the optical imaging light has sufficient irradiance to polymerize the resin. In such cases, the optical imaging light may be directed to the build surface for a time short enough to avoid substantially polymerizing the resin. Therefore, it may be useful to limit the total light energy directed to the build surface 190. For example, in some embodiments, the optical imaging light is at least about 1 microjoule / cm². 2 (μJ / cm 2 ), 2 μJ / cm 2 , 3 μJ / cm 2 , 4 μJ / cm 2 , 5 μJ / cm 2 , 6 μJ / cm 2 7 μJ / cm 2 , 8 μJ / cm 2 9 μJ / cm 2 , 10 μJ / cm 2 , 20 μJ / cm 2 , 30 μJ / cm 2 , 40 μJ / cm 2 , 50 μJ / cm 2 , 60 μJ / cm 2 70 μJ / cm 2 , 80 μJ / cm 2 90 μJ / cm 2 , 100 μJ / cm 2 , 200 μJ / cm 2 , 300 μJ / cm 2 , 400 μJ / cm 2 500 μJ / cm 2 , 600 μJ / cm 2 700 μJ / cm 2 , 800 μJ / cm 2 900 μJ / cm²2 , 1000 μJ / cm 2 or more of total light energy. In some embodiments, the optical imaging light has at most about 1000 μJ / cm 2 , 900 μJ / cm 2 , 800 μJ / cm 2 , 700 μJ / cm 2 , 600 μJ / cm 2 , 500 μJ / cm 2 , 400 μJ / cm 2 , 300 μJ / cm 2 , 200 μJ / cm 2 , 100 μJ / cm 2 , 90 μJ / cm 2 , 80 μJ / cm 2 , 70 μJ / cm 2 , 60 μJ / cm 2 , 50 μJ / cm 2 , 40 μJ / cm 2 , 30 μJ / cm 2 , 20 μJ / cm 2 , 10 μJ / cm 2 , 9 μJ / cm 2 , 8 μJ / cm 2 , 7 μJ / cm 2 , 6 μJ / cm 2 , 5 μJ / cm 2 , 4 μJ / cm 2 , 3 μJ / cm 2 , 2 μJ / cm 2 , 1 μJ / cm 2 or less of total light energy. In some embodiments, the optical imaging light has a total light energy within a range defined by any two of the aforementioned values. In some embodiments, the optical imaging light has an exposure time of at least about 0.1 seconds (s), 0.2 s, 0.3 s, 0.4 s, 0.5 s, 0.6 s, 0.7 s, 0.8 s, 0.9 s, 1 s or more. In some embodiments, the optical imaging light has an exposure time of at most about 1 s, 0.9 s, 0.8 s, 0.7 s, 0.6 s, 0.5 s, 0.4 s, 0.3 s, 0.2 s, 0.1 s or less. In some embodiments, the optical imaging light has an exposure time within a range defined by any two of the aforementioned values.

[0048] In some embodiments, the optical imaging light is filtered to remove wavelengths of light that could polymerize the resin at the build surface 190. For example, in some embodiments, the system 100 further includes one or more filters (not shown in Figure 1 or 2) capable of filtering out one or more wavelengths of light from the illumination light or modulated illumination light. In some embodiments, one or more filters are interference filters. In some embodiments, one or more filters are absorption filters. In some embodiments, one or more filters are low-pass filters. In some embodiments, the low-pass filter is capable of transmitting light with wavelengths of up to approximately 325 nanometers (nm), 330 nm, 335 nm, 340 nm, 345 nm, 350 nm, 355 nm, 360 nm, 365 nm, 370 nm, 375 nm, 380 nm, 385 nm, 390 nm, 395 nm, 400 nm, 405 nm, 410 nm, 415 nm, 420 nm, 425 nm, 430 nm, 435 nm, 440 nm, 445 nm, and 450 nm or longer. In some embodiments, one or more filters are band-pass filters. In some embodiments, the bandpass filter is capable of transmitting light with wavelengths in the following ranges: approximately 325 nm to approximately 375 nm, approximately 335 nm to approximately 385 nm, approximately 340 nm to approximately 385 nm, approximately 340 nm to approximately 390 nm, approximately 345 nm to approximately 395 nm, approximately 350 nm to approximately 400 nm, approximately 355 nm to approximately 405 nm, approximately 360 nm to approximately 410 nm, approximately 365 nm to approximately 415 nm, approximately 370 nm to approximately 420 nm, approximately 375 nm to approximately 425 nm, approximately 380 nm to approximately 430 nm, approximately 385 nm to approximately 435 nm, approximately 390 nm to approximately 440 nm, approximately 395 nm to approximately 445 nm, or approximately 400 nm to approximately 450 nm.

[0049] In some embodiments, optical imaging light is directed onto the build surface 190 by the SLM system 114. In some embodiments, the optical imaging light has a color that does not polymerize the resin on the build surface 190. Projecting the optical imaging light through the SLM system 114 eliminates the need for additional optical components within the system 100, making the system 100 more compact. In addition, the SLM system 114 may be used to modulate the optical imaging light to enable the use of structured illumination imaging techniques.

[0050] The controller 170 may be capable of estimating the flat-field response of the large-area microstereolithography system or optical imaging system 118 using multiple images of the product at different locations. For example, a single point of illumination can be directed towards the build plane 190 by allowing only one pixel of the SLM system 114 to transmit illumination light. This can illuminate one pixel of the image sensor 250 in the optical imaging system 118. The illumination can then be moved so that different pixels are illuminated. This procedure can be repeated for substantially all pixels of the image sensor 250 in the optical imaging system 118. Alternatively, the illumination light may be directed towards multiple pixels and then moved. By obtaining a sufficient number of these images, the flat-field response of the image sensor 250 in the optical imaging system 118 can be obtained, for example, using a deconvolution operation.

[0051] The controller 170 may be capable of calibrating one or more pixels of the SLM system 114. For example, in some embodiments, the controller 170 may grayscale a slice 140, multiple regions 150, or the current region 160 before directing illumination light onto the SLM system 114. If some pixels of the SLM system 114 are brighter than others, the average light power across the entire SLM system 114 can be equalized by applying an appropriate grayscale mask. This may allow the SLM system 114 to achieve more uniform illumination power across the build surface 190.

[0052] The controller 170 may be able to instruct the SLM system 114 to adjust the focus of the illumination light or modulated illumination light. In some embodiments, the focus of the illumination light or modulated illumination light is adjusted by translating a lens (not shown in Figure 1 or 2) that collimates the light from the SLM system 114. In some embodiments, the controller 170 commands the lens to make such a change of position. In some embodiments, the focus of the illumination light or modulated illumination light is adjusted by translating the SLM system 114. In some embodiments, the controller 170 commands the SLM system 114 to make such a change of position. In some embodiments, the focus of the illumination light or modulated illumination light is adjusted using one or more mirrors (not shown in Figure 1 or 2) that can be translated to change the optical path length of the illumination light or modulated illumination light. In some embodiments, the controller 170 commands one or more mirrors to make such a change of position. In some embodiments, the focus of the illumination light or modulated illumination light is adjusted by moving the entire system 100. In some embodiments, the controller 170 commands the entire system 100 to perform such a repositioning. In some embodiments, the focus of the illumination light or modulated illumination light is adjusted by moving the build surface 190. In some embodiments, the controller 170 commands the build surface 190 to perform such a repositioning.

[0053] In some embodiments, the controller 170 can perform closed-loop control of illumination light or modulated illumination light. For example, in some embodiments, the controller 170 can instruct the beam unit 110 to adjust the intensity or exposure time of the light beam 113 based on the measured total light power emitted by the beam unit 110. In some embodiments, the controller 170 can instruct the beam unit 110 to adjust the intensity or exposure time of the light beam 113 based on the measured fluorescence signal, scattering signal, or reflection signal on the build surface 190. In some embodiments, the controller 170 can instruct the SLM system 114 to adjust the exposure time or the modulation of one or more pixels of the SLM system 114 based on the measured total light power emitted by the SLM system 114. In some embodiments, the controller 170 can instruct the SLM system 114 to adjust the exposure time or the modulation of one or more pixels of the SLM system 114 based on the measured fluorescence signal on the build surface 190.

[0054] The OCLAuSL system 100 may also include other optical components necessary for directing and aligning the beam, or as conceivable by those skilled in the art, at other locations (e.g., between the SLM 114 and the beam steering system 230, a common lens, or downstream of the aperture 180). For example, the adjustment optics 220, beam delivery optics 240, and / or imaging optics 260 may be, or include, beam splitters capable of (i) receiving modulated illumination light from the SLM system 114 and directing the modulated illumination light to a selected build area 197 of the build surface 190, and (ii) receiving imaging light from an object or product being manufactured by the system and directing the imaging light to the optical imaging system 118, as shown in Figure 10. Such configurations and others are within the scope of this disclosure.

[0055] Figure 3 shows a flowchart of an example of an optically calibrated large-area microstereolithography (OCLAuSL) method 300 according to at least one embodiment of the present disclosure. The operation of the elevator, the on / off of the beam, and the imaging display are controlled and synchronized by a computer, controller, or processor.

[0056] In step 310, method 300 includes creating a 3D model of the desired object or product. This can be done, for example, by 3D scanning an example of the desired object or product using computer-aided design (CAD), or by other means known in the art. For example, the vascular structure of a living human organ can be mapped in three dimensions using a computer-aided tomography (CAT) scanner and contrast agent injection into the blood.

[0057] In step 320, method 300 includes dividing the 3D model into multiple slices. The number of slices may determine, for example, the Z resolution or Z voxel size that the desired object or product will be generated by the OCLAuSL system. For example, if the desired object or product is 100 centimeters tall, subdividing it into 10,000 slices will result in a minimum feature size of 100 microns along the Z axis.

[0058] In step 330, method 300 includes subdividing the currently selected slice into multiple slice regions. The slice may be subdivided into, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 1000, 10000, or more slice regions. These slice regions may be the same or similar in size, or they may be different in size. The slice regions may be adjacent, overlap, or have gaps between adjacent slice regions.

[0059] In step 340, method 300 includes sending the selected slice region to a spatial light modulator (SLM) so that the SLM generates an image of the selected slice region within the light beam produced by the optical system. In some examples, the brightness of each pixel in the SLM image may have only two possible values: on or off. In other examples, the brightness of each pixel in the SLM image may be on a grayscale with possible values ​​of, for example, 128, 256, 512, 1024, or more, where larger values ​​represent brighter pixels and smaller values ​​represent darker pixels.

[0060] In step 350, method 300 includes sending the SLM image to an adjustable beam delivery system.

[0061] In step 360, method 300 includes instructing a beam delivery system adjustable to direct an SLM image onto a selected build region of the build plane, the location of the selected build region within the build plane corresponding to the location of the selected slice region within a selected 2D slice. The projected image is focused on the build plane containing a photocurable resin or liquid, so that chemical light forms a specific shape or pattern within the material. This exposes the photosensitive liquid resin at this location to the SLM image, causing the resin portions where the SLM image is bright to solidify, while leaving the liquid resin portions where the SLM image is dark unchanged. Brighter pixels or longer exposure times result in a greater energy dose being delivered to the resin, and consequently, more crosslinking in that particular voxel within the build plane. More crosslinking may be associated with higher density and / or stiffer voxels in the solidified resin, while fewer crosslinking may be associated with lower density and / or softer voxels in the solidified resin. Once crosslinking is complete, or at least sufficient to maintain the integrity of the pattern within the exposed area, the process proceeds to step 370.

[0062] In step 370, method 300 includes selecting the next slice region within the selected slice. Then execution returns to step 340. However, if all slice regions of the current slice have been imaged onto the build plane, there is no next slice region, and execution proceeds to step 380.

[0063] In step 380, method 300 includes lowering an elevator platform within a resin tank. The elevator platform and resin tank are shown, for example, in Figure 6. Lowering the elevator platform also lowers the current slice to a deeper level in the resin tank, allowing new resin to flow into the build surface. In some cases, the elevator platform is lowered by a Z distance equal to the thickness of the current slice. In other cases, sometimes called “dunking,” the elevator platform is lowered by a larger amount and then raised to a Z distance equal to the thickness of the current slice. Dunking allows new resin, uncontaminated by crosslinking byproducts, or new resin containing amounts of inhibitors and initiators to balance locally depleted resin, to flow into the build surface.

[0064] In step 390, method 300 involves selecting the next slice in the 3D model. Then execution returns to step 330. However, if all slices in the 3D model have already been selected, there is no next slice, and execution proceeds to step 395.

[0065] In step 395, the manufacturing of the desired object or product is completed. In other words, the layer-by-layer process defined above continues until the finished 3D object is produced.

[0066] It should be understood that in other embodiments, the steps of Method 300 may be performed in a different order than that shown in Figure 3, additional steps may be provided before, between, and after the steps, and / or some of the steps described may be replaced or eliminated. One or more of the steps of Method 300 may be performed by one or more devices and / or systems described herein, such as components of the controller 170 (see Figure 1) and / or the processor circuit 850 (see Figure 8).

[0067] Figure 4 is a schematic diagram of at least a portion of the build surface 190 of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. In the example shown in Figure 4, the build surface 190 is subdivided into eight build regions 195a-195g. Product slices 410 of product 420 being manufactured by the OCLAuSL system span all eight build regions. The product slices 410 may, for example, have multiple exposed, crosslinked, and solidified resins, and multiple stacked product slices 410 constitute the finished product.

[0068] In the example shown in Figure 4, the build surface 190 also includes four reference components, targets, test substrates, or test patterns 430 that can be imaged by an optical imaging system 118 (see Figure 1) to facilitate calibration of the OCLAuSL system by the controller 170 (see Figure 1). In some embodiments, the reference components, targets, or test patterns 430 can be constructed within the build surface together with the product slice 410 by projecting them onto the build surface using light of a chemical wavelength that can expose or crosslink the resin. In other embodiments, the reference components, targets, or test patterns 430 may be placed within the build surface or projected onto the build surface using light of a wavelength that cannot expose or crosslink the resin. The reference targets or test patterns may have, for example, radial symmetry (e.g., dots), have a changing spatial frequency pattern (e.g., pairs of lines of different widths), have a plurality of changing spatial frequency patterns with different orientations (e.g., spoke targets), or include other patterns known in the art, including recognizable text, symbols, or combinations thereof. The number, size, shape, location, orientation, and other characteristics of the reference components, targets, or test patterns 430 may differ from those illustrated or described herein without departing from the spirit of this disclosure.

[0069] In one example, if region 195, as shown in Figure 4, is exposed in alphabetical order as 195a, 195b, 195c, 195d, 195e, 195f, 195g, and finally 195h, beam movement is minimized. It may be apparent that other sequences, such as adehgfcb or some other possible order, are more efficient. Other continuous or discrete exposure patterns, including circles or spirals, may also be desirable, minimizing the beam movement and / or total exposure time required to complete a layer. More generally, exposure patterns may be chosen to minimize the time required to move the optical element that refocuses the projection between subsequent exposures. A spiral pattern is one example because the refocusing element does not need to move much. Alternatively, exposure patterns may be chosen to minimize the average or maximum time between the exposure of a given tile and the exposure of adjacent or overlapping neighbors. Raster scanning does this well. In some cases, this can reduce the appearance of seams between adjacent or overlapping tiles. Other configurations and optimizations, including combinations of these, may be used as alternatives or additional measures. Exposure patterns in the form of circles or spirals may enable the generation of more uniform layers or reduce artifacts at boundaries between regions in a given layer. Such patterns can place greater emphasis on generating structures near the center of a given layer where finer structures may be required. An example of a spiral pattern is shown in Figure 11. In some embodiments, the scanning pattern may be a spiral pattern extending inward from the periphery of the build surface, a raster scanning pattern, a scanning pattern with multiple concentric circles, or an S-curve pattern.

[0070] The resolution and voxel size of the finished object or product 420 depend on the resolution of the SLM 114 (see Figures 1 and 2) and the size of each build area 195 within the build surface 190. Similarly, the maximum size of the finished object or product 420 depends on the number and arrangement of the build areas, as well as their sizes. For example, if each of the eight build areas 195 shown in Figure 4 is 1024 mm × 768 mm in size, and the resolution of the SLM 114 is 1024 × 768 pixels, then the voxel size on the build surface will be 1 × 1 mm, and the total area of ​​the build surface will be 2048 mm × 3072 mm, which can be increased by adding new build areas.

[0071] Figure 5 is a schematic diagram of at least a portion of the build surface 190 of an example of an OCLAuSL system according to at least one embodiment of the present disclosure. Build regions 195a, 195b, 195c, and 195d are visible. In the example shown in Figure 5, these build regions overlap, resulting in overlapping regions 510a including both build region 195a and build region 195b, overlapping region 510b including build region 195b and build region 195c, overlapping region 510c including build region 195c and build region 195d, overlapping region 510d including build region 195d and build region 195a, and overlapping region 510e including build region 195a, 195b, 195c, and 195d. When build regions meet or when there is a gap between two build regions, a seam can be created in the finished product (whether unintentionally or intentionally). Conversely, when build regions overlap, assuming proper registration between the build regions, the seam can be minimized or eliminated, and therefore the overall quality of the product may (or may be perceived as) be higher than when a seam is present.

[0072] Figure 6 is a schematic side cross-sectional view of at least a portion of an example of an OCLAuSL system 100 according to at least one embodiment of the present disclosure. The OCLAuSL beam unit 110, the projected image beam 185, the elevator system 620, and the photocurable resin tank 640 located within the tank enclosure 630 are visible. Inside the resin tank 640 are a build platform 650 connected to the elevator system 620, a substrate 660 placed on the build platform, and a finished layer 670 of the desired object or product 420. Other configurations are possible and are within the scope of the present disclosure.

[0073] The OCLAuSL system 100 can be improved by collectively combining multiple OCLAuSL beam units 110 to create a super-large-area projection microstereolithography system. Such collective integration allows for a virtually unlimited increase in the size of objects that can be manufactured by the system. Images exposed within the build plane by two or more beam units 110 work together to utilize their larger overall area. In the case of two beam units 110, the covered area is twice that of the beam unit minus the overlap area. Similarly, when three beam units 110 are combined, they can cover three times that of the beam unit minus the overlap area, and so on. Thus, increasingly larger products can be manufactured.

[0074] In the non-limiting embodiment shown in Figure 6, four OCLAuSL beam units 110 are grouped together such that their projected image beams 185 slightly overlap within the build plane 190. In some embodiments, these OCLAuSL beam units 110 may be controlled by a single controller 170 (see Figure 1) so that their operations coordinate to form a 2D slice 410 of the desired product 420 within the build plane 190. In other embodiments, each OCLAuSL beam unit 110 may be controlled by its own controller 170, with the controllers 170 coordinating their operations to achieve an equivalent level of coordination. Other configurations are also possible and are within the scope of this disclosure.

[0075] As can be seen in Figure 6, the build surface 190 is located at the top of the photocurable resin tank 640. The photocurable resin tank can be several tens or several hundreds of centimeters in length, width, or depth, or it may be any other size, both larger and smaller.

[0076] In some embodiments, the resin has a relatively soft, hydrophilic polymer material. In non-limiting examples, the main resin component may include a monomer or polymer such as polyethylene glycol diacrylate (PEGDA, molecular weight greater than 575, specifically 575-6000) and / or gelatin methacrylate (GelMA), a photoinitiator such as lithium phenyl-2,4,6-trimethylbenzoyl phosphinate (LAP), Irgacure 2959, and / or ruthenium, an absorbent such as tartrazine, and a diluent such as PBS and / or water. A typical formulation may contain 10-50% by weight of PEGDA (a mixture of any single PEGDA with a molecular weight of 700-6000) or 10-25% by weight of GelMA, 2-68 mmol (mM) of LAP, 2-20 mM of tartrazine, with the remaining weight % being water. One example of a formulation that has been shown to function well is 40 wt% PEGDA 6000, 34 mM LAP, 9 mM tartrazine, 15 wt% GelMA, 17 mM LAP, and 2.255 mM tartrazine. The term “resin” should be interpreted broadly to include liquids, gels, solutions, suspensions, and colloids of plastics, monomer-based photocurable materials, and / or softer hydrophilic polymer-based materials, or combinations thereof.

[0077] The disclosed apparatus and method also provide an optically calibrated large-area microstereolithography system for producing ceramic and / or metal parts. In one example, a beam delivery system projects and scans a layer image onto a curable resin containing metal or ceramic, whether suspended as particles, chemically bonded as special molecules, or otherwise. The system then produces a desired object or product using a base polymer containing metal or ceramic dispersed throughout the object. In some cases, this can result in a material with mixed properties, such as a conductive polymer or a polymer with higher-than-usual tensile or compressive strength. In other cases, the base polymer is subsequently removed by thermal decomposition, leaving a product composed of colloidal metal or ceramic particles. In some cases, these colloidal particles can be sintered to form a solid material.

[0078] In one example, the thickness of the build surface is equal to the thickness of slice 140 of the 3D model 120 (see Figure 1) (within reasonable mechanical tolerances expected by those skilled in the art). At the start of product manufacturing, the build surface 190 can be located between the substrate 660 and the top surface of the photocurable resin tank 640 and may have a layer of liquid photocurable resin with a thickness equal to the desired product slice 140.

[0079] Each time a new layer 670 is completed (for example, fully cured, or at least partially cured enough to maintain the integrity of any newly created structure within the layer), the elevator system 620 moves the build platform 650 and substrate 660 downward in the resin tank by a distance equal to the thickness of the next slice 140. In some embodiments, all slices 140 are of equal thickness, while in other embodiments, the slices 140 may be of varying thickness. In some embodiments, the elevator system 620 “dunks” the build platform 650, substrate 660, and completed layer 670 by lowering them by a distance greater than the desired slice thickness in the z-direction (for example, 10, 100, 1,000, or 10,000 times the slice thickness, or other values ​​both greater and less than the slice thickness) before raising them to the height of the desired slice thickness. In some cases, the photocuring of product layer 670 generates chemical by-products or impurities (including, but not limited to, oxidizing agents, radicals, fine particles of partially crosslinked resin, and by-reaction products) that may interfere with the photocuring of subsequent layers. This dunking process can help disperse such by-products or impurities within the resin tank, ensuring that the build surface 190 is occupied by a clean layer of unreacted resin. The above describes a top-down system. It should be understood that this disclosure also includes bottom-up and lateral embodiments having appropriately oriented elevator systems.

[0080] In some embodiments, the lifting mechanism may be connected to the build platform by arms suspended over the rim of the bat or by a set of posts or shafts passing through the bottom of the bat. In some embodiments, these shafts may pass through O-rings or other seals to prevent resin leakage around them. In some embodiments, the lifting system includes a stage movable on the Z-axis using a servo motor or stepper motor under the control of a processor, such as controller 170 in Figure 1.

[0081] Figure 7a is a perspective view of at least a portion of the build surface 190 of an example of the OCLAuSL system 100 according to at least one embodiment of the present disclosure. A slice 410 of a desired object or product 420 is visible within the build surface 190. The structure of the product slice 410 closely resembles the structure of a particular model slice 140 of the 3D model 120 (see Figure 1). The product slice 410 may be a continuous solid piece, or it may consist of discrete solidified voxels or other structures that are not necessarily connected within the build surface. Thus, three-dimensional grids, networks, foams, and other complex 3D shapes, including macroscopic shapes with microscopic structural forms, can be formed layer by layer as new patterns are exposed.

[0082] Figure 7b is a perspective view of at least a portion of a curable resin vat 640 of an example of an OCLAuSL system 100 according to at least one embodiment of the present disclosure. The completed layer 670 of the desired object or product 420 is visible together with the currently manufactured layer or slice 410 located above the completed layer 670. Figure 7b also shows the planned layer 770 of the desired object or product 420. These planned layers may represent the contents of several slices 130 of a 3D model 120, for example, as shown in Figure 1. The 3D model 120 of the desired object or product 420 may include a mixture of macroscopic and microscopic forms, whether similar or dissimilar to each other.

[0083] In some cases, photocurable resins, upon curing, produce flexible materials similar in stiffness to human collagen or other human tissue components. In such cases, the desired object or product may be a 3D representation of a vascular system, cartilage, or other part of a synthetic human organ, into which human cells can be introduced to produce a completed synthetic organ. Partial organs, animal organs, organoids, grafts, and other tissues can be produced similarly. In some cases, the polymer material can then be removed from the finished product. For example, the polymer material can be removed mechanically, by dissolution, by chemical decomposition, by a change in pH, or by catalytic action (e.g., enzymatic catalysis).

[0084] Figure 8 is a schematic diagram of a processor circuit 850 according to an embodiment of the present disclosure. The processor circuit 850 may be implemented, for example, in the controller 170 of the OCLAuSL beam unit 110 (see Figure 1), or in other devices or workstations (e.g., third-party workstations, network routers, etc.), or in a cloud processor or other remote processing unit, as necessary for implementing the method. As shown, the processor circuit 850 may include a processor 860, a memory 864, and a communication module 868. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0085] The processor 860 may include any combination of general-purpose computing devices, reduced instruction set computing (RISC) devices, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other related logic devices, including a central processing unit (CPU), digital signal processor (DSP), ASIC, controller, or mechanical and quantum computers. The processor 860 may also have other hardware devices, firmware devices, or any combination thereof configured to perform the operations described herein. The processor 860 may also be implemented as a combination of multiple computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working in conjunction with a DSP core, or any other such configuration.

[0086] Memory 864 may include cache memory (e.g., the cache memory of processor 860), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or combinations of different types of memory. In one embodiment, memory 864 includes a non-temporary computer-readable medium. Memory 864 may store instructions 866. Instructions 866 may include instructions that, when executed by processor 860, cause processor 860 to perform the operations described herein. Instructions 866 may also be referred to as code. The terms “instruction” and “code” should be broadly interpreted to include any type of (one or more) computer-readable statements. For example, the terms “instruction” and “code” may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "codes" may consist of one computer-readable statement or multiple computer-readable statements.

[0087] The communication module 868 may include any electronic and / or logic circuits to facilitate direct or indirect communication of data between the processor circuit 850 and other processors or devices. In this regard, the communication module 868 may be an input / output (I / O) device. In some examples, the communication module 868 facilitates direct or indirect communication between various elements of the processor circuit 850 and / or controller 170 (see Figure 1). The communication module 868 may communicate within the processor circuit 850 through a number of methods or protocols. Serial communication protocols include, but are not limited to, US SPI, I. 2This may include C, RS-232, RS-485, CAN, Ethernet®, ARINC 429, MODBUS, MIL-STD-1553, or any other suitable method or protocol. Parallel protocols include, but are not limited to, ISA, ATA, SCSI, PCI, IEEE-488, IEEE-1284, and other suitable protocols. Where appropriate, serial and parallel communications may be bridged by a UART, USART, or other suitable subsystem.

[0088] External communication (including, but not limited to, software updates, firmware updates, pre-configured sharing between the processor and a central server, or reading from the system) can be achieved using any suitable wireless or wired communication technology, such as cable interfaces like USB, micro USB, Lightning, or FireWire interfaces, Bluetooth®, Wi-Fi, ZigBee, Li-Fi, or cellular data connections such as 2G / GSM, 3G / UMTS, 4G / LTE / WiMax, or 5G. For example, a connection to a cloud service can be established using Bluetooth Low Energy (BLE) wireless for data transmission and software patch reception. The controller may be configured to communicate with a remote server or a local device such as a laptop, tablet, or handheld device, and may include a display capable of showing state variables and other information. Information may also be transmitted over a physical medium such as a USB flash drive or memory stick.

[0089] Figure 9 shows an example of an optical imaging system physically separated from the optical system, SLM system, and beam delivery system of an optically calibrated large-area microstereolithography system according to an embodiment of the present disclosure. As shown in Figure 9, the optical system 112, SLM system 114, and beam delivery system 116 may be located at a certain distance from the optical imaging system 118. For example, the optical system 112, SLM system 114, and beam delivery system 116 may be located at least about 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 70 cm, 80 cm, 90 cm, and 100 cm or more from the optical imaging system 118. The optical system 112, SLM system 114, and beam delivery system 116 may be located at least about 100 cm, 90 cm, 80 cm, 70 cm, 60 cm, 50 cm, 40 cm, 30 cm, 20 cm, and 10 cm or less from the optical imaging system 118. The optical system 112, the SLM system 114, and the beam delivery system 116 may each be placed at a distance from the optical imaging system 118 within a range determined by any two of the aforementioned values. Placing the optical system 112, the SLM system 114, and the beam delivery system 116 at a certain distance from the optical imaging system 118 may allow the use of an imaging optical system 260 that is not constrained by the lens or aperture 180 used to project the projected image beam onto the build surface 190. For example, the lens or aperture 180 may be configured to efficiently transmit blue light to the build surface 190. It may be desirable to image light of other wavelengths, such as the green, yellow, red, or infrared components of the electromagnetic spectrum. Projecting blue light and imaging light of these other regimes may be difficult because there may be few materials that transmit both blue light and light of these other regimes.

[0090] In some embodiments, it may be desirable to image through the same part of the optical system used to project illumination light. For example, Figure 10 shows an example of an optically calibrated large-area microstereolithography system that uses a beam splitter or dichroic to perform large-area microstereolithography and optical imaging through a common optical element. As shown in Figure 10, the optically calibrated large-area microstereolithography system may have an optical system 112, an SLM system 114, a beam delivery system 116, and an optical imaging system 118, as described herein. The system may further have an illumination source 1010 capable of emitting imaging illumination light (for example, for fluorescence imaging). The illumination source may direct the imaging illumination light through a first beam splitter or dichroic 1020 to a second beam splitter or dichroic 1030. The imaging illumination light may then be directed towards the build plane 190 through the beam delivery system 116 and some calibration optical system. The optical system 112 and the SLM system 114 can direct the modulated illumination light to the second beam splitter 1030, which can then deliver the modulated illumination light to the beam delivery system 116 and the build surface 190. When the imaging illumination light interacts with the product at the build surface, imaging light (e.g., fluorescence) may be emitted by the product. This imaging light can then travel through an optical element, such as the first beam splitter 1020. Since this imaging light may have a different wavelength from the imaging illumination light, it can be directed to the imaging optical system 260 and detected by the image sensor 250. Thus, the first and second beam splitters 1020 and 1030 can each enable imaging through a portion of the same optical system used to project the illumination light.

[0091] Figure 11 shows an exemplary spiral scanning pattern. As shown in Figure 11, the scan begins in the first region 1101, located near the center of the product. The scan then moves outward in a spiral pattern to the second region 1102, the third region 1103, the fourth region 1104, the fifth region 1105, and so on, as indicated by the arrows. This process can be continued for any number of regions, as indicated.

[0092] As will be readily apparent to those skilled in the art after familiarizing themselves with the teachings herein, the optically calibrated large-area microstereolithography system is advantageous in that it enables the rapid, reliable, and reproducible manufacturing of large objects (e.g., hundreds of millimeters or larger) with microscopic shapes (e.g., sizes of tens of microns or less) at a pixelation scale too minute to be perceived by the human eye, with little to no detectable seams. Thus, the optically calibrated large-area microstereolithography system is found to satisfy the needs in the art by providing means for calibrating the projected image and the optical system for generating it, in order to ensure consistent voxel size and hardening level (regardless of size) across the entire build surface.

[0093] Numerous modifications are possible to the examples and embodiments described herein. For example, the build surface and / or resin chamber may be larger or smaller than those shown herein. The resolution may be higher (or the voxel size may be smaller) than that described herein, limited only by the classical diffraction limit. Conversely, the techniques described herein can be equally applied to systems with extremely large build volumes and / or voxel sizes for the production of industrial-scale components. The composition of the resin chamber and the corresponding chemical wavelengths capable of crosslinking the resin may differ from those disclosed herein. The cured resin may be transparent to infrared, visible, or ultraviolet light, or it may be translucent, opaque, or a combination thereof. The resin may be or contain dye molecules or dye particles (including fluorescent molecules or particles) to impart any desired color or combination of colors to the finished part, including colors imperceptible to the human eye. The technologies described herein can be used to produce prototypes or finished products (e.g., tools, enclosures, models, or components) for virtually any industry, including but not limited to medical, arts, science, manufacturing, agriculture, automotive, aerospace, and consumer electronics. Non-limiting examples include dental crowns and implants, biological skeletons, transplantable tissues and organs, supercapacitors, and food.

[0094] The logical operations constituting the embodiments of the technology described herein may be referred to in various ways as operations, steps, objects, elements, components, or modules. It should also be understood that these may occur or be executed in any order unless otherwise explicitly stated, or unless a particular order is inherently required by the stated wording.

[0095] For example, all references to directions, such as upper, lower, inner, outer, upward, downward, left, right, side, front, back, top, bottom, up, down, vertical, horizontal, clockwise, counterclockwise, proximal, and distal, are used solely for identification purposes to aid the reader's understanding of the claimed subject matter and do not impose any limitation with respect to the position, orientation, or use of the optically calibrated microstereolithography system. References to connections, such as mounted, joined, connected, and linked, should be interpreted broadly and, unless otherwise specified, may include intermediate members between sets of elements and relative movement between elements. Thus, a reference to a connection does not necessarily mean that two elements are directly connected and fixed to each other. The term “or” shall be interpreted as meaning “and / or” rather than “exclusively or.” The term “having” does not exclude other elements or steps, and the indefinite articles “a” or “an” do not exclude the plural. Unless otherwise stated in the claims, the values ​​stated are to be interpreted merely as examples and should not be construed as limiting.

[0096] The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of the optically calibrated microstereolithography system as defined in the claims. While various embodiments of the claimed subject matter have been described above with a certain degree of detail or by reference to one or more individual embodiments, those skilled in the art can make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the claimed subject matter.

[0097] Further other embodiments are contemplated. In intent, all matters included in the above description and shown in the accompanying drawings are to be construed as merely illustrative examples of specific embodiments, and not as limiting. Modifications in detail or structure may be made without departing from the fundamental elements of the subject matter as defined in the following claims.

[0098] List of various embodiments of this disclosure Embodiment 1: A system for producing a product, comprising: a large-area microstereolithography system capable of producing the product by photopolymerizing sequential layers of a curable resin on a build surface; an optical imaging system; and a controller that communicates with the large-area microstereolithography system and the optical imaging system, the controller capable of instructing the optical imaging system to acquire one or more optical images of the product or reference components located on the build surface, and adjusting parameters related to the large-area microstereolithography system based on the one or more images.

[0099] Embodiment 2: The system of Embodiment 1, wherein the optical imaging system is positioned substantially close to the build surface.

[0100] Embodiment 3: The optical imaging system is the system of Embodiment 1 or 2, comprising a bright-field imaging system, a fluorescence imaging system, a reflectance imaging system, a scattering imaging system, a refractive index difference imaging system, a luminescence imaging system, a polarization analysis imaging system, a differential interference contrast imaging system, a phase-contrast microscopy imaging system, a Raman scattering imaging system, a spectral imaging system, an optical coherence tomography (OCT) imaging system, or an interference imaging system.

[0101] Embodiment 4: The system of any one of Embodiments 1 to 3, wherein the controller is further capable of processing one or more optical images of the product to identify a first region of the product having cured resin and a second region of the product having uncured resin, and adjusting the parameters based on the one or more images comprises (i) comparing the first region of the product with an intended first region of the product, (ii) comparing the second region of the product with an intended second region of the product, and (iii) adjusting the parameters to reduce a first difference between the first region of the product and the intended first region of the product, and a second difference between the second region of the product and the intended second region of the product.

[0102] Embodiment 5: The system of any of Embodiments 1 to 4, wherein the controller is further capable of processing one or more optical images of the product to determine the physical or chemical properties of the product, and adjusting the parameters based on the one or more images comprises (i) comparing the physical or chemical properties of the product with the intended physical or chemical properties of the product, and (ii) adjusting the parameters to reduce the difference between the physical or chemical properties of the product and the intended physical or chemical properties of the product.

[0103] Embodiment 6: A system according to any one of Embodiments 1 to 5, wherein the parameters are the intensity of illumination light emitted by the large-area microstereolithography system, the focal point of the illumination light, the exposure time of the illumination light, or the frequency of the illumination light.

[0104] Embodiment 7: Any system of Embodiments 1 to 6, wherein the system further comprises a non-optical imaging system, and the controller can further instruct the non-optical imaging system to acquire one or more non-optical images of the product.

[0105] Embodiment 8: The system of Embodiment 7, wherein the non-optical imaging system includes an ultrasonic imaging system or a photoacoustic imaging system.

[0106] Embodiment 9: The system of any one of Embodiments 1 to 8, wherein the system further has a substantially uniform light-emitting surface substantially near the build surface, and the controller is capable of (i) directing illumination light from the large-area microstereolithography system to illuminate the substantially uniform light-emitting surface, (ii) instructing the optical imaging system to acquire one or more images of the substantially uniform light-emitting surface, and (iii) calibrating the large-area microstereolithography system based on the one or more images.

[0107] Embodiment 10: The system of Embodiment 9, wherein the illumination light is Köhler illumination light.

[0108] Embodiment 11: A system according to any of Embodiments 1 to 10, wherein the controller is further capable of estimating the flat-field response of the optical imaging system based on one or more optical images.

[0109] Embodiment 12: The system further comprises a test substrate positioned substantially close to the build surface, and the controller is capable of (i) directing illumination light from the large-area microstereolithography system or another illumination source to illuminate the test substrate, (ii) instructing the optical imaging system to acquire one or more test images of the test substrate, and (iii) calibrating the large-area microstereolithography system based on the one or more test images, according to any of Embodiments 1 to 11.

[0110] Embodiment 13: The large-area microstereolithography system comprises an optical system, a spatial light modulator (SLM) system, a tank having the curable resin, the tank in which the build surface is located, a lifting system, and a large-area microstereolithography controller, wherein the large-area microstereolithography controller receives a plurality of two-dimensional slices of the product, the plurality of two-dimensional slices correspond to a three-dimensional model of the product, and for each of the plurality of two-dimensional slices, the two-dimensional slice is divided into a plurality of regions, and for each of the plurality of regions, the S A system according to any of embodiments 1 to 12, which is capable of instructing the optical system to provide illumination light to the LM system, instructing the SLM system to modulate the illumination light based on the region to form modulated illumination light, instructing the beam delivery system to deliver the modulated illumination light to the build surface, thereby generating a portion of the product layer within the curable resin, the portion corresponding to the region, the layer corresponding to the two-dimensional slice, and instructing the elevator system to raise or lower the build surface based on the three-dimensional model, thereby changing the position of the build surface within the tank.

[0111] Embodiment 14: The beam delivery system is the system of Embodiment 13, wherein the beam delivery system has a rotating polygon mirror.

[0112] Embodiment 15: The system of Embodiment 13 or 14, wherein the optical system, the SLM system, and the beam delivery system are physically separated from the optical imaging system.

[0113] Embodiment 16: Any system of any of Embodiments 13 to 15, further comprising: (i) a beam splitter capable of receiving the modulated illumination light from the SLM system and directing the modulated illumination light to the build surface; and (ii) a beam splitter capable of receiving imaging light from the product and directing the imaging light to the optical imaging system.

[0114] Embodiment 17: A system according to any of embodiments 13 to 16, wherein the controller is further capable of calibrating one or more pixels of the SLM system.

[0115] Embodiment 18: Any system of Embodiments 13 to 17, further comprising a lens capable of collimating the illumination light or the modulated illumination light.

[0116] Embodiment 19: A system of any of Embodiments 13 to 18, wherein the large-area microstereolithography controller can further instruct the SLM system to adjust the focus of the illumination light or the modulated illumination light.

[0117] Embodiment 20: A system according to any of embodiments 13 to 19, further comprising one or more mirrors capable of changing the optical path length of the illumination light or the modulated illumination light.

[0118] Embodiment 21: The large-area microstereolithography controller is further capable of moving the tank of curable resin relative to the optical system, the SLM system, the beam delivery system, or the optical imaging system, according to any system of Embodiments 13 to 20.

[0119] Embodiment 22: A system according to any of Embodiments 13 to 21, wherein the large-area microstereolithography controller is further capable of directing the illumination light through the SLM system.

[0120] Embodiment 23: A system according to any of embodiments 13 to 22, further comprising one or more filters capable of filtering out one or more wavelengths of the illumination light or the modulated illumination light.

[0121] Embodiment 24: The beam delivery system is a system of any of Embodiments 13 to 23, which is capable of delivering the modulated illumination light in a spiral pattern outward from the center of the build surface, a spiral pattern inward from the periphery of the build surface, a raster scanning pattern, a scanning pattern having multiple concentric circles, or an S-curve pattern.

[0122] Embodiment 25: A method for producing a product, comprising: generating the product by photopolymerizing sequential layers of a curable resin on a print surface using a large-area microstereolithography system; acquiring one or more optical images of the product using an optical imaging system; and adjusting parameters related to the large-area microstereolithography system based on the one or more images.

Claims

1. It is a system for producing products. A large-area microstereolithography system capable of producing the aforementioned product by photopolymerizing sequential layers of curable resin on the build surface, Optical imaging system, A controller that communicates with the large-area microstereolithography system and the optical imaging system, The optical imaging system is instructed to acquire one or more optical images of the product or reference component located on the build surface. Based on one or more of the aforementioned optical images, the parameters related to the large-area microstereolithography system are adjusted. A controller that can do this, It has, The system further has a substantially uniform light-emitting surface substantially near the build surface, and the controller can further (i) direct illumination light from the large-area microstereolithography system to illuminate the substantially uniform light-emitting surface, (ii) instruct the optical imaging system to acquire one or more images of the substantially uniform light-emitting surface, and (iii) calibrate the large-area microstereolithography system based on the one or more images of the substantially uniform light-emitting surface. system.

2. The system according to claim 1, wherein the optical imaging system is positioned substantially close to the build surface.

3. The optical imaging system according to claim 1, wherein the optical imaging system comprises a brightfield imaging system, a fluorescence imaging system, a reflectance imaging system, a scattering imaging system, a refractive index difference imaging system, a luminescence imaging system, a polarization analysis imaging system, a differential interference contrast imaging system, a phase difference microscopy imaging system, a Raman scattering imaging system, a spectral imaging system, an optical coherence tomography (OCT) imaging system, or an interference imaging system.

4. The system according to claim 1, wherein the controller is further capable of processing one or more optical images of the product to identify a first region of the product having cured resin and a second region of the product having uncured resin, and adjusting the parameters based on the one or more optical images comprises (i) comparing the first region of the product with an intended first region of the product, (ii) comparing the second region of the product with an intended second region of the product, and (iii) adjusting the parameters to reduce a first difference between the first region of the product and the intended first region of the product, and a second difference between the second region of the product and the intended second region of the product.

5. The system according to claim 1, wherein the controller is further capable of processing one or more optical images of the product to determine the physical or chemical properties of the product, and adjusting the parameters based on the one or more optical images comprises (i) comparing the physical or chemical properties of the product with the intended physical or chemical properties of the product, and (ii) adjusting the parameters to reduce the difference between the physical or chemical properties of the product and the intended physical or chemical properties of the product.

6. The system according to claim 1, wherein the parameters include the intensity of illumination light emitted by the large-area microstereolithography system, the focal point of the illumination light, the exposure time of the illumination light, or the frequency of the illumination light.

7. The system according to claim 1, further comprising a non-optical imaging system, wherein the controller can further instruct the non-optical imaging system to acquire one or more non-optical images of the product.

8. The system according to claim 7, wherein the non-optical imaging system comprises an ultrasonic imaging system or a photoacoustic imaging system.

9. The system according to claim 1, wherein the illumination light comprises Köhler illumination light.

10. The system according to claim 1, wherein the controller is further capable of estimating the flat-field response of the optical imaging system based on one or more optical images.

11. The system according to claim 1, further comprising a test substrate positioned substantially close to the build surface, wherein the controller is capable of (i) directing illumination light from the large-area microstereolithography system or another illumination source to illuminate the test substrate, (ii) instructing the optical imaging system to acquire one or more test images of the test substrate, and (iii) calibrating the large-area microstereolithography system based on the one or more test images.

12. The aforementioned large-area microstereolithography system is Optical systems and, Spatial Light Modulator (SLM) system, A tank having the curable resin, wherein the build surface is located inside the tank, Elevator system and A large-area microstereolithography controller, It has, The aforementioned large-area microstereolithography controller is The system receives multiple two-dimensional slices of the product, and these multiple two-dimensional slices correspond to a three-dimensional model of the product. For each of the aforementioned two-dimensional slices, The two-dimensional slice is divided into multiple regions, For each of the aforementioned multiple regions, The optical system is instructed to provide illumination light to the SLM system, The SLM system is instructed to modulate the illumination light based on the region to form modulated illumination light. The beam delivery system is instructed to deliver the modulated illumination light to the build surface, thereby generating a portion of the product layer within the curable resin, the portion corresponding to the region, and the layer corresponding to the two-dimensional slice. The elevator system is instructed to raise or lower the build surface based on the three-dimensional model, thereby changing the position of the build surface within the tank. It is possible. The system according to claim 1.

13. The beam delivery system has a rotating polygon mirror, according to claim 12.

14. The system according to claim 12, wherein the optical system, the SLM system, and the beam delivery system are physically separated from the optical imaging system.

15. The system according to claim 12, further comprising: (i) a beam splitter capable of receiving the modulated illumination light from the SLM system and directing the modulated illumination light toward the build surface; and (ii) a beam splitter capable of receiving imaging light from the product and directing the imaging light toward the optical imaging system.

16. The system according to claim 12, wherein the controller is further capable of calibrating one or more pixels of the SLM system.

17. The system according to claim 12, further comprising a lens capable of collimating the illumination light or the modulated illumination light.

18. The system according to claim 12, wherein the large-area microstereolithography controller can further instruct the SLM system to adjust the focus of the illumination light or the modulated illumination light.

19. The system according to claim 12, further comprising one or more mirrors capable of changing the optical path length of the illumination light or the modulated illumination light.

20. The system according to claim 12, wherein the large-area microstereolithography controller is further capable of moving the tank of curable resin relative to the optical system, the SLM system, the beam delivery system, or the optical imaging system.

21. The system according to claim 12, wherein the large-area microstereolithography controller is further capable of directing the illumination light through the SLM system.

22. The system according to claim 12, further comprising one or more filters capable of filtering out one or more wavelengths of the illumination light or the modulated illumination light.

23. The beam delivery system is capable of delivering the modulated illumination light in the form of an outward spiral pattern from the center of the build surface, an inward spiral pattern from the periphery of the build surface, a raster scanning pattern, a scanning pattern having a plurality of concentric circles, or an S-shaped curve pattern, according to claim 12.

24. The method of producing a product, The product is produced by photopolymerizing sequential layers of curable resin on the printed surface using a large-area microstereolithography system. Using an optical imaging system, acquire one or more optical images of the product. Based on one or more of the aforementioned optical images, the parameters related to the large-area microstereolithography system are adjusted. Having, This method further, The illumination light from the large-area microstereolithography system is directed to illuminate a substantially uniform light-emitting surface substantially near the printed surface. Using the optical imaging system, one or more images of the substantially uniform light-emitting surface are acquired. The large-area microstereolithography system is calibrated based on one or more images of the substantially uniform light-emitting surface. Having, method.

Images