High speed light valve system

Abstract

An additive manufacturing system includes a high power laser to form a high flux laser beam. A 2D patternable light valve having a structure responsive to electron emission is positioned to receive and pattern light received from the high power laser.

Description

[0001] Related applications

[0002] This disclosure is part of a non-provisional patent application claiming priority to U.S. Patent Application No. 63 / 107,310, filed October 29, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure generally relates to the operation of high-speed optical valve systems. More specifically, it describes the use of electron emission and a novel architecture suitable for high-speed operation.

[0004] background

[0005] High-power laser systems capable of operating at high throughput for extended periods are useful for additive manufacturing and other applications that can benefit from the use of patterned high-energy lasers. Unfortunately, many existing high-power laser systems for additive manufacturing or other applications cannot operate at full speed due to the relatively slow operation of the optical valves. Brief description of the attached diagram

[0007] The following figures illustrate non-limiting and non-exhaustive embodiments of the present disclosure, wherein, unless otherwise stated, similar reference numerals refer to similar parts throughout the various figures.

[0008] Figure 1A An example of a high-speed reflective light valve (RLV) for metal additive manufacturing is shown;

[0009] Figure 1B(i) shows an example of a high-speed electron beam addressed RLV (EBA-RLV);

[0010] Figure 1B(ii) shows an example of an embodiment of an EBA-RLV incorporating an electron beam array;

[0011] Figure 1B(iii) shows an example of an EBA-RLV embodiment incorporating a photoconductivity separation layer;

[0012] Figure 1C An example of high-speed direct-coupled self-emitting display addressing RLV (e-RLV) is shown;

[0013] Figure 1D(i) shows an example of a high-speed dual photoconductor LV;

[0014] Figure 1D(ii) shows an example of a high-speed dual photoconductor LV utilizing edge field switching;

[0015] Figure 1E An example of high-speed LV utilizing in-plane switching is shown;

[0016] Figures 1F(i) and 1F(ii) together illustrate the architecture of the high-speed LV system (HSLV unit) 100F(i) and an example of its timing 100F(ii);

[0017] Figure 1F(iii) shows an example of the use of a multi-point LV switch for the high-speed LV system of Figure 1F(i);

[0018] Figure 1G An example of an array architecture using HSLV cells is shown;

[0019] Figure 2 A block diagram of an additive manufacturing system based on a high-throughput optical valve is shown, which supports beam dumps, high-speed optical valves, and thermal engines.

[0020] Figure 3 An additive manufacturing system based on a high-throughput, high-speed optical valve is shown.

[0021] Figure 4 Another embodiment of an additive manufacturing system based on a high-throughput, high-speed optical valve is shown; and

[0022] Figure 5 Another embodiment of additive manufacturing based on high-throughput, high-speed optical valves is shown, which combines additive manufacturing with a switch station method for recycling and further utilizing waste energy.

[0023] Detailed description

[0024] In the following description, reference is made to the accompanying drawings, which form a part of this specification, and which illustrate specific exemplary embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it should be understood that modifications can be made to the various disclosed embodiments, and other embodiments can be utilized without departing from the scope of this disclosure. Therefore, the following detailed description is not to be considered limiting.

[0025] In the following disclosure, the additive manufacturing system includes a high-power laser to form a high-throughput laser beam. A 2D patternable optical valve with an electron-emission-responsive structure is positioned to receive and pattern the light received from the high-power laser.

[0026] The light valve (LV) technology is limited in its ability to switch pixel speeds. In some of the embodiments described herein:

[0027] Using the described LV in a metal additive manufacturing system (M-AM LV) allows for a significant increase in speed (more than 1,000 times greater than conventional LVs) by changing to materials that can support rapid changeover times (such as LiNbO3, BBO, KDP, or K*DP).

[0028] Using the described LV in the M-AM LV system allows for reduced complexity, while enabling frame rates that are 10 to 1000 times higher than existing LV M-AM systems.

[0029] Using the described LV in an M-AM system allows for increased speed and reduced complexity due to the ability to use edge field switching (FFS) in the LV system. This reduction is due to the reduced thickness of the LEOL when using edge field switching (which has the expected speed increase of 4 to 10 times compared to existing LV M-AM systems);

[0030] Using the described LV in M-AM LV allows for in-plane switching within the LV, with a corresponding increase in speed due to the reduced thickness of its LEOL layer. This speed increase is similar to the speed increase of the edge field (4x-10x), but with reduced complexity compared to that required in FFS.

[0031] Using the described LV in the M-AM LV system allows the use of PI units in a binary tree with slowly patterned LVs and slices the outputs of 2N LVs into a sequence in time, resulting in an overall frame rate increase of N times compared to the conventional M-AM LV system;

[0032] The use of the described LVs in the M-AM LV system allows for the selection of arrays of 1D or 2D slow LVs by using solid-state scanning (SSS) unpatterned LVs (the speed of which depends on the number of setup angles that the SSS can reach), thereby improving speed. Such a system also allows for random access sorting of slow patterned LVs.

[0033] Figure 1AAn example of a velocity-reflective light valve (RLV) 100A for metal additive manufacturing is shown. The RLV (110A) consists of a top transparent conductive oxide (TCO, 120A) deposited on top of a photoconductor (130A). A high-reflectivity mirror (140A) is deposited on the bottom of 130A and has >99.9% reflectivity for light in the 990nm–1070nm range and >75% reflectivity for light in the 265nm–500nm range. An alignment or impedance layer is deposited on the inside of 140A and is used for interfacing with a linear electro-optic device (LEO, 160A). Another alignment or impedance layer (170A) is used for interfacing with 160A and is attached to a bottom TCO (180A) deposited on a support substrate (190A).

[0034] A low-flux patterned write beam (200A) of λ2 passes through 120A and enters 130A, causing 130A to reduce its resistance in a circuit consisting of 120A, 130A, 140A, 150A, 160A, 170A, and terminating at 180A. This circuit is controlled by an external controller (not shown). The change in resistance in 130A reflects the intensity pattern in 200A and allows the unpatterned electric field seen at 120A to become a patterned field at 140A. This patterned field is also applied to 160A, which causes a change in the birefringence of the material, as seen by the high-flux laser beam (HFL, 210A) entering 110A. The high-flux beam (210A) has a wavelength of λ1 and enters 110A from right to left by passing through 190A, 180A, and 170A before interacting with the patterned birefringence of 160A. The patterned birefringence at 160A applies the pattern from 200A to 210A as it passes through 160A. The HFL passes through 160A and 150A before reflecting off 140A, and again through 160A, 170A, 180A, and 190A before the patterned HFL in the form of 220A leaves 110A. The two passes through 160A require 160A to be structured, so that the two passes apply the pattern from 200A to 210A. Because the full effect of 160A is felt in the two-pass method, its physical distance can be reduced by more than 50%, allowing speeds more than four times higher than standard transmission LV. The patterned HFL beam (220A) passes through the beam pattern splitter (230A), allowing the desired pattern 240A to be re-imaged into the printing chamber, while unwanted patterns (not shown for clarity) are sent to the beam dump or switch station system.

[0035] In the absence of 200A, the unpatterned HFL beam (250A) enters 110A and passes through 190A, 180A, 170A, 160A, and 150A, reflects off 140A, and then passes through 150A, 160A, 170A, 180A, and 190A again before exiting 110A as the unpatterned HFL beam 260A. Upon impact with 230A, it is completely rejected (as 270A) from entering the beam dump or switch station system, as will be discussed later. Figure 5 The subject of discussion.

[0036] Figure 1B(i) illustrates an example of a high-speed electron beam addressed RLV (EBA-RLV) 100B(i). The EBA-RLV 100B9(i) consists of a secondary emitter gate (115B(i)) that collects negative charges scattered from the surface of the structured via array (120B(i)), negative charges emitted from 120B(i) from ballistic charges, or negative charges pulled off as a function of the voltage of 120B(i). 115B(i) allows 120B(i) to be directed to charge “pixels” defined by the electron beam to have positive, neutral, or negative charges, and allows pixels to be better defined than in systems without such a screen. The via layer (120B(i)) can be structured using an anisotropic matrix, a silicon or polymer-based array of electrically conductive vias commonly used as fan-out intermediate layers in microelectronics, or a flexible layer with a similar microscopic or nanoscopic arrangement through the conductive path, in which sheet-like conductive particles are dispersed throughout the volume of the anisotropic matrix. Attached to 120B(i) is a high-reflectivity mirror (HRM, 130B(i)) that reflects >99% of light in the 990nm–1070nm range. Attached to 130B(i) is an alignment or impedance layer (140B(i)) that sets the orientation of the linear electro-optic layer (150B(i)). An additional alignment / impedance layer (160B(i)) helps define the orientation of 150B(i). A transparent conductive oxide (TCO, 170B(i)) terminates the circuit of 110B(i), which consists of 115B(i), 120B(i), 130B(i), 140B(i), 150B(i), and 160B(i). A supporting substrate (180B(i)) provides stability for 110B(i).

[0037] The electron source defining the pixel in 110B(i) is generated by an electron gun (or a tunneling electron source, a Spindt-type cold cathode emitter, or a similar electron beam generator) that emits a free electron stream (200B(i)). Deflection and focusing structures allow the beam to sweep across the surface of 115B(i) in the "x" (210B(i)) and "y" (220B(i)) directions, which, in conjunction with 115B(i), defines the charged pixel in 120B(i) and the varying voltage field across 150B(i). Modulating the intensity of 200B(i) along with the waveform applied to 115B(i) allows a grayscale image to be applied to 150B(i). Current and voltage control for 190B(i) is transmitted from the electron beam electronics module (270B(i)) to 190B(i) via control line 230B(i). Similarly, the control of the voltage waveforms for 210B(i) and 220B(i) is transmitted from 260B(i) (XY deflection driver) controlled by 270B(i) via control lines 240B(i) and 250B(i), respectively. Furthermore, 270B(i) controls the voltage and current waveforms of 115B(i) via control line 280B(i). 270B(i) is controlled by the LV electronics module (290B(i)), which also controls the voltage waveform of 170B(i) via control line 300B(i).

[0038] 110B(i) operates as a light valve, requiring an unpatterned high-throughput beam (310B(i)) to enter 110B(i) by passing through 180B(i), 170B(i), 160B(i), 150B(i), and 140B(i) and reflecting off 130B(i) before exiting 180B(i). A charge image deposited on 115B(i) and 120B(i) by grating scanning 200B(i) is transmitted as a voltage image on 150B(i). This voltage image acts on 150B(i), causing a change in its optical response. The optical response of 150B(i) is typically a change in its birefringence, but can also be a phase change, spectral, scattering, absorption, or reflection response, as seen through 310B(i). A voltage image is applied to 150B(i) to create an optical response image, which is then applied to 310B(i) via a dual-channel array from 310B(i) to 150B(i), transforming 310B(i) into a patterned HFL beam (320B(i)). 320B(i) exits from 110B(i) and strikes a beam pattern separator (330B(i)), which separates the desired patterned image (370B(i)) from the unwanted image. The desired image (370B(i)) is relayed to the printing chamber, while the unwanted image (not shown) is sent to the beam storage area or switch station system.

[0039] In the case where an unpatterned HLF beam (340B(i)) enters 100B(i) (where the electron beam system does not present an image), the light is unaffected by and unpatterned by 110B(i), and exits as unpatterned (350B(i)), and upon impact with 330B(i), it is redirected into 360B(i) as it is sent to the beam dump or switching station system. The frame rate of the EBA-RLV system can exceed E6 frames per second and will likely be limited by the switching time of 150B(i) rather than by the capability of the scanning electron beam electronics.

[0040] Figure 1B(ii) illustrates an example of an embodiment of the EBA-RLV 100B(ii) incorporating an electron beam array. The light valve 110B(ii) is activated by a 2D addressable electron emitter (120B(ii)) that includes rows and columns of individual addressable field emitters (125B(ii)) in an active matrix arrangement. Activation of such an emitter (125B(ii)) allows electron emission (127B(ii)) to be locally deposited onto 110B(ii), resulting in the generation of charged pixels (130B(ii)) and influencing modifications to the LEO layer within 110B(ii). Row and column addressing of 120B(ii) is controlled by an electron beam array driver (160B(ii)) and transmitted to 120B(ii) via control lines 140B(ii) (column control lines) and 150B(ii) (row control lines). The LV electronic device control 160B(ii) includes a voltage waveform applied to the internal TCO of 110B(ii) via control line 180B(ii). As described in Figure 1B, the incoming unpatterned HFL (190B(ii)) enters 110B(ii) and exits as a patterned HFL (200B(ii)) wherever the electron beam pixel has been activated. 200B(ii) is split by the beam pattern splitter (210B(ii)) into the desired patterned HFL beam (220B(ii)) (which is imaged onto the printing chamber) and the undesired pattern entering the beam dump or switch station system. If an unpatterned HFL beam (230B(ii)) enters 110B(ii) where no electron beam pixel is activated, it will leave 110B(ii) as an unpatterned HFL beam (240B(ii)) and be completely rejected by 210B(ii), and will be guided to the beam dump or switch station system as 250B(ii). The frame rate of the 2D addressable EBA-RLV is limited by the array driver (typically E2 frames per second).

[0041] Figure 1B(iii) illustrates an example embodiment of an EBA-RLV 100B(iii) that incorporates a photoconductor separation layer between the gate anode and the tip entrance, and makes the base of the cathode emitter array transparent to the write beam. This effectively converts the EBA-RLV into an optically addressed EBA-RLV, as shown in 110B(iii). The EBA-RLV (110B(iii)) components are depicted in Figure 1B. In this embodiment, the scanning electron beam is replaced by an optically addressed cold cathode emitter array (113B(iii)) that includes a photoconductor (120B(iii)) separating the anode from the tip support structure. In this embodiment, the patterned write beam (115B(iii)) of λ2 passes through 113B(iii) and activates the photoconductor 125B(iii), allowing an electron stream (127B(iii)) to be emitted from the tip directly below 125B(iii). This electron stream (127B(iii)) generates a patterned charged region (130B(iii)) within 110B(iii), which reflects the pattern in 115B(iii). The charged pattern transmits voltage from the outside of 110B(iii) to both ends of the LEO layer within 110B(iii). Control lines 140B(iii), 150B(iii), and 153B(iii) control the voltage waveforms applied to the cold cathode array, the photoconductor anode layer, and the secondary emission gate within 110B(iii), respectively. The electron beam array electronics (155B(iii)) controls the waveforms on 140B(iii), 150B(iii) and 153B(iii), and works in conjunction with the LV electronics (157B(iii)), which also controls the waveforms transmitted to the TCO in 110B(iii) via control line 160B(iii).

[0042] The desired pattern is applied to the HFL beam by initially allowing the unpatterned HFL beam (170B(iii)) to enter 110B(iii) and interact with the LEO, which has already been activated by 115B(iii), via 126B(iii), 127B(iii), and 130B(iii). The LEO applies the same pattern as the pattern inherent in 115B(iii) to 170B(iii) and exits 110B(iii) as a patterned HFL beam (180B(iii)) upon reflection from the HRM of 110B(iii). The patterned HFL beam (180B(iii)) strikes the pattern separator (190B(iii)), and the desired beam (200B(iii)) is relayed to the printing chamber, while the unwanted pattern goes to the beam dump or switch station system. As in the previous case, an unpatterned HFL beam (210B(iii)) enters 110B(iii) in an inactive region, reflects off the HRM within 110B(iii), and leaves the EBA-RLV as 220B(iii) while still unpatterned. 220B(iii) is completely rejected by 190B(iii) and becomes 230B(iii) to enter the beam dump or switching station system. The advantage of 100B(iii) is that the frame rate depends on the speed at which 115B(iii) and the LEO material can be switched, and with LiNbO3 as the LEO material and a fast DLP system as the source of 115B(iii), 100B(iii) is limited to the 50kHz-100kHz frame rate limit inherent in DLP systems.

[0043] Figure 1CAn example of a high-speed, directly coupled self-emitting display (RLV) 100C is shown. The RLV (110C) is directly coupled to a self-emitting display (130C) operating at λ2. Optical coupling between 130C and 110C is performed via a small lens array (120C), an aperture array, or similar proximity focusing (directly mating the surface of 130C to a thin photoconductor layer within 110C). The self-emitting display can be an OLED, an LED (as a display driver) array, a microLED display, or any kind of surface-emitting display that can emit at λ2 (in the 265nm to 500nm wavelength range). Light emitted by a set of pixels forms a patterned beam (140C) within 130C, causing the photoconductor elements to directly contact or couple via 120C to transfer voltages outside 110C to both ends of the LEO layer within 110C and apply variations to the optical properties of the LEO, as described above. The self-emission display is controlled by a high-speed display driver (160C) via control line 150C, while 110C is controlled by LV electronics (170C), as previously described. An unpatterned HFL beam (189C) enters 110C, passes through the LEO layer in the area affected by 150C, addressed by 140C. The image applied by 140C is transmitted to 180C via the action of 150C on the LEO layer, and exits as a patterned HFL beam 190C as 180C is reflected from the HRM layer within 110C and passes through the LEO layer and intermediate layer. The desired pattern (200C) in 190C is separated by the action of a beam pattern splitter (190C), and then the desired pattern is imaged onto the printing chamber. The undesired pattern (not shown) is reflected off 195C and imaged onto the beam dump or switch station system. In the absence of a pattern or light emitted from 130C, the unpatterned HFL beam 210C travels through 110C and does not leave in a patterned manner under the action of LEO, because there is no activation from 130C; it leaves 130C as an unpatterned HFL beam (220C) and is completely rejected by 195C, and is imaged into the beam dump field or switching station system as waste light (230C). The frame rate achievable at 100C depends on the LEO layer inside 110C and the switching speed of 130C, both typically >1000 frames per second.

[0044] Figure 1D(i) shows an example of a high-speed dual photoconductor LV (DPCLV) 100D(i). The DPCLV includes a top transparent conductive oxide (TCO, 120D(i)), a top photoconductor layer (PC, 130D(i)), a top impedance / alignment layer (IML, 150D(i)), a top linear electro-optic layer (TLEOL, 160D(i)), an intermediate layer group (170D(i), shown in more detail in 340D(i)), a bottom LEOL (B-LEOL, 180D(i)), a bottom IML (190D(i)), a bottom PC layer (210D(i)), and a bottom TCO (220D(i)).

[0045] The DPCLV system (110D(i)) operates through the dual action of two counter-propagating patterned write beams, both entering 110D(i) from the right (230D(i)) and the left (240D(i)) respectively. The patterned write beam entering 110D(i) from the right (230D(i)) activates 130D(i) to form a patterned voltage image within 130D(i), which is transmitted to 160D(i) via the T-LEOL's response to this patterned voltage change (270D(i)). Similarly, the patterned write beam entering 110D(i) from the left (240D(i)) performs the same transmission to the B-LEOL via 260D(i) and 280D(i). An unpatterned HFL beam (300D(i)) of λ1 enters 110D(i), passes through 270D(i) and 260D(i), and interacts with the patterned responses of 270D(i) and 260D(i). Through its interaction with these two LEOLs, it exits 110D(i) as a patterned HFL beam 310D(i). Similarly, in the region of 110D(i) not patterned by 230D(i) and 240D(i), an unpatterned HFL beam (320D(i)) passes through 110D(i) unaffected by LEOLs, becoming 330D(i)—still an unpatterned HFL beam. The patterned 310D(i) is imaged onto a print bed after passing through a beam pattern splitter (not shown), where the desired image enters, while the undesired pattern, along with 330D(i), is rejected and imaged onto a beam dump or switch station system, for example, regarding Figure 5 The subject of discussion.

[0046] The intermediate layer group (170D(i)) within 110D(i) is shown in detail as 340D(i). This structure acts as an intermediate support for 160D(i) and 180D(i), and consists of an intermediate top IML (350D(i)), an intermediate top TCO (260D(i)), an intermediate support layer (370D(i)), an intermediate bottom TCO layer (380D(i)), and an intermediate bottom IML (390D(i)).

[0047] Because the LEOL is reduced to half or less of that of a standard high-speed transmission LV, the switching speed can be more than four times faster than that of a standard high-speed transmission LV.

[0048] Figure 1D(ii) illustrates an example of a high-speed dual photoconductor LV100D(ii) utilizing edge field switching. Edge field switched LEOL systems use different types of linear electro-optic materials, where the optical properties of the material (especially its birefringence) are activated by electric field gradients. These gradients are caused by the edge field between two adjacent activated regions. The edge field is typically higher in terms of local field strength and has a greater impact on the LEOL; therefore, the LEOL thickness can be significantly reduced compared to a normally operating LV, and the increase in frame rate is proportional to the square of the thickness reduction. In this embodiment, the edge field is generated by using the dual photoconductor concept introduced in Figure 1D. An example of an edge field DPCLV is depicted in 110D(ii) and consists of a top TCO (120D(ii)), a top photoconductor (130D(ii)), a top IML (140D(ii)), a LEOL (150D(ii)), a bottom IML (160D(ii)), a bottom photoconductor (170D(ii)), and a bottom TCO (175D(ii)).

[0049] A patterned write beam 180D(ii) of (λ2) enters 110D(ii) from the left and applies a voltage pattern (200D(ii)) within 130D(ii). A second patterned write beam (carrying the same pattern, 190D(ii)) enters from the right and enters 110D-I, collinear (slightly offset) with 180D(ii) and propagates in the opposite direction, applying a voltage pattern (210D(ii)) within 170D(ii). The edge field within 150D(ii) generated by the offset between the two voltage patterns (200D(ii) and 210D(ii)) drives the LEO within 150D(ii) to produce a patterned optical response within 150D-I, depicted as 250D(ii) (details of the voltage edge fields within 130D(ii) and 170D(ii) are omitted for clarity). An unpatterned HFL beam (240D(ii)) enters 110D(ii), and the optical response pattern in 250D(ii) is applied to 240D(ii) such that, upon exiting 110D(ii), the HFL beam becomes patterned (260D(ii)), containing the same spatial image in both 180D(ii) and 190D(ii). The desired pattern within 260D(ii) is imaged into the printing chamber, while its undesired pattern is imaged into the beam dump or switch station system, for example, regarding... Figure 5 The subject of discussion.

[0050] The two write beams (180D(ii) and 190D(ii)) do not need to carry the same image; the edge field will be set regardless of the image presented on each channel. The response on 240D(ii) will be as described above, but the final pattern applied on 260D(ii) will be a convolution of the two images contained in 180D(ii) and 190D(ii). Furthermore, the response of 150D(ii) to the edge field generated by 200D(ii) and 210D(ii) depends on the presence of the two fields within the same time interval. The temporal overlap of 180D(ii) and 190D(ii) provides additional speed improvement and depends on the relaxation time of 150D(ii) and the two photoconductors (130D(ii) and 170D(ii)) (providing fast LV).

[0051] In the presence of one write beam or the absence of two write beams (180D(ii) and 190D(ii)) and the entry of an unpatterned HFL beam (270D(ii)) into 110D-I, no patterned optical response is contained in 150D(ii), and 270D(ii) exits 110D(ii) as an unpatterned HFL beam (280D(ii)). This unpatterned HFL beam (280D(ii)) will be imaged onto the beam dump or switch station system, for example, regarding... Figure 5 The subject of discussion.

[0052] Figure 1E An example of a high-speed LV 100E utilizing in-plane switching is shown. The LV 110E consists of a top TCO (120E), a photoconductor (130E), a top IML (140E), a LEO layer (150E), a bottom IML (160E), and a supporting substrate (170E). The 150E is composed of a material responsive to edge fields and is typically an electrically controlled birefringent liquid crystal (ECB-LC) that has been vertically aligned (VA). In-plane LC systems can be very thin, but this requires the LC in such devices to have very high birefringence to allow sufficient contrast to be feasible. Since the frame rate of an LC-based LV varies with the square of the reduction in thickness compared to the nominal LV, the frame rate can be one to two orders of magnitude larger than the nominal frame rate.

[0053] Activation of 110E originates from two patterned write beams (180E and 190E), both operating at λ² and entering 110E from the left, proceeding to 130E, where they generate two voltage patterns (200E and 210E) within 130E. The field interference pattern between 200E and 210E generates an in-plane edge field (denoted by 220E) between the two patterns just passing through 140E and entering 150E. The in-plane edge field modifies the LEO material within 150E (230E) according to the interference field 220E and imposes an optical response within 230E that reflects the images contained within 180E and 190E.

[0054] The HFL beam (240E) enters 110E from the left and interacts with the patterned portion of 150E (depicted as 250E) caused by the in-plane switching between two similar interferences as described above; details of its presentation to 150E are omitted for clarity. The patterned optical response in 150E (250E) applies a pattern to 240E, and it exits as the patterned HFL beam (260E), where the desired patterned portion continues into the printing chamber, while the undesired portion enters the beam dump or switch station system. In the absence of one or both write beams, the unpatterned HFL beam (270E) interacts with the unpatterned volume of 150E, leaving 110E still unpatterned as 280E, and is imaged into the beam dump or switch station system, e.g., regarding Figure 5 The subject of discussion.

[0055] Figures 1F(i) and 1F(ii) together illustrate the architecture of a high-speed LV system (HSLV unit) 100F(i) and an example of its timing 100F(ii). In this schematic layout, there are high-speed region LV (aka PI unit) switches and low-speed patterned LVs, as well as supporting optics for implementing the architecture, which are omitted for clarity. An unpatterned HFL beam (110F(i)) enters 100F(i) and is switched by PI unit 120F(i) into one of two possible paths / channels (130F(i) or 240F(i)). Assuming 120F(i) switches the incoming 110F(i) into channel 130F(i), the unpatterned HF(i)L beam enters the second layer of the unpatterned PI unit (140F(i)), which can place 130F(i) into one of two paths / channels (150F(i) or 160F(i)). Assume 140F(i) is activated, causing the unpatterned HFL beam on 130F(i) to be switched to channel 150F(i). The unpatterned HFL beam 150F(i) enters the patterned LV 170F(i) and is patterned during time slot t1. The patterned HF(i)L beam leaves 170F(i) and travels along path 190F(i), where it is switched to 220F(i) by the unpatterned third-layer PI unit (210F(i)). The patterned HFL beam travels along 220F(i) and enters the fourth-layer unpatterned PI unit (230F(i)), which converges various signals onto channel 340F(i), where the patterned HFL beam is imaged into the printing chamber during time slot t1.

[0056] Similarly, the path of the unpatterned HFL from 110F(i) through 120F(i) and into 130F(i), through 140F(i) and into 160F(i) allows the unpatterned HFL beam to be patterned by the patterned LV 180F(i) at time t2. The output of 180F(i) travels along 200F(i) into 210F(i), where 210F(i) places the patterned HFL beam 200F(i) onto 220F(i), which again allows 230F(i) to converge the image onto 340F(i) in time slot t2 for transmission to the printing chamber.

[0057] Similarly, the initial unpatterned HFL beam can be sent to the patterned LV 280F(i) via PI unit 250F(i) (at time t3) along paths 240F(i) and 260F(i). The patterned HFL result from 280F(i) travels along 300F(i) and is converged into 340F(i) via PI units 320F(i) and 230F(i) (at time slot t3) along paths 300F(i) and 330F(i). Similarly, the unpatterned HFL beam can be patterned by the patterned LV 290F(i) in time slot t4 by passing through PI unit 250F(i) through 240F(i) and 270F(i). In time slot t4, the convergence of the patterned HFLs output from 290F(i)(310F(i)) to 340F(i) is accomplished by traversing paths 310F(i) and 330F(i), then 320F(i), and finally 230F(i). The sequence emerges from the HFL beam patterned at 230F(i), which originates from the patterns placed on that beam by 170F(i), 180F(i), 280F(i), and 290F(i) in time slots t1, t2, t3, and t4, respectively, thus producing a 4x improvement in frame rate compared to what could be achieved using only a single patterned LV.

[0058] The timing sequence is demonstrated at 350F(i), where 360F(i) is the timing sequence of 120F(i) (the first layer of the PI cell). The second layer of the PI cell (140F(i) and 250F(i)) has timing diagrams depicted in 370F(i) and 420F(i), respectively. The slowly patterned LVs (170F(i), 180F(i), 280F(i), and 290F(i)) have timing diagrams depicted in 400F(i), 410F(i), 430F(i), and 440F(i), respectively. The third layer of the PI cell (210F(i) and 320F(i)) has timing diagrams depicted in 380F(i) and 450F(i), respectively. The fourth layer of the PI cell (230F(i)) has a timing diagram depicted in 390F(i). The timing diagram of the output of the high-speed LV system (channel 340F(i)) is depicted in 460F(i). Comparing the frame rate of a single patterned LV (480F(i)) (see the dashed box around the timing diagram of 400F(i)) with the frame rate of the LV system (dashed box 490F(i)), it can be seen that the frame rate of the LV system is 4 times that of the 2-layer up / down system. This architecture allows for a speed improvement of 2N times relative to a single LV system, where N is the number of PI cells in the system before / after patterned LVs. This architecture requires the PI cell switching speed to be more than 4 times that of the slowly patterned LVs. The arrangement depicted in 100F(i) is the cell of a high-speed binary switching LV system.

[0059] Figure 1F(iii) illustrates an example of the use of the multi-point LV switch 100F(ii) of the high-speed LV system of Figure 1F(i). A single high-speed multi-point unpatterned LV switch is used for both the input and output gates, feeding into / out of a 1D or 2D array of slowly patterned LVs. An unpatterned HFL beam (110F(i)) enters a multi-point scanning / gazing LV (120F(i)) and is scanned to any one of the slowly patterned LV arrays depicted as 160F(i). On either side of 160F-I is a prism array that takes an angled unpatterned HFL (130F(i)) and straightens it to optimize the spatial resolution of any of the patterned LVs in 160F(i). Since each patterned LV is located at a precise position relative to 120F-I, 150F(i) can be a static array of prism components. Before passing through another prism array (170F(i)), the HFL beam is patterned in time slot ti by any of the patterned LVs within 160F(i). The second prism array (170F(i)) deflects the patterned HFL beam (180F(i)) into a second unpatterned high-speed multi-point LV, which is configured to redirect 180F(i) to the output channel of 100F(i) to form part of the patterned pulse sequence imaged into the printing chamber. While 130F(i) and 180F(i) (respectively) denote the first channels entering and exiting the patterned LV array, the last channels entering and exiting the array (respectively) are denoteed by 140F(i) and 190F(i).

[0060] Several different methods exist for utilizing this arrangement to perform channel selection, sequentially from the first channel (130F(i) / 180F(i)) to the last channel (140F(i) / 190F(i)) or any variation thereof, including not starting with 130F(i) / 180F(i) or ending with 140F(i) / 190F(i). Compared to the frame rate of a standard (single) LV system, this method offers a frame rate improvement equal to the number (M times) of unique and controllable pointing directions that 120F(i) / 200F(i) can execute. Furthermore, this method requires 120F(i) / 200F(i) to be M times faster than any of the slowly patterned LVs in 160F(i), where M equals the number of unique addressable directions that 120F(i) / 200F(i) can reach. The 100F(i) arrangement is the cell of a high-speed multi-point switching LV system.

[0061] Figure 1GAn example of an architecture 100G using an HSLV cell array is shown. Note that while a schematic diagram using a binary high-speed architecture (110G) is shown, multi-point embodiments are also possible. The binary-switched LV system comprises unpatterned high-speed area LV switches (120G as an example) and slowly patterned LVs (130G as an example). A 3D representation of 110G is depicted in 140G, where 150G and 160G are equivalent to 120G and 130G, respectively. An end view of 140G is depicted in 170G, where 180G and 190G are equivalent to 120G and 130G, respectively. This cell of the high-speed LV system can be arranged (200G), where 210G represents one such cell. Arranging 170G into 200G allows the concept of a high-speed LV system to be extended in space to realize alternative architectures for high-speed area printing engines, switch stations (e.g., regarding...). Figure 5 (The system under discussion) or solid-state scanning system.

[0062] A wide range of lasers with various wavelengths can be used in conjunction with the described phase-change optical valve system. In some embodiments, possible laser types include, but are not limited to: gas lasers, chemical lasers, dye lasers, metal vapor lasers, solid-state lasers (e.g., fiber lasers), semiconductor lasers (e.g., diode lasers), free-electron lasers, gas dynamic lasers, "nickel-like" samarium lasers, Raman lasers, or nuclear-pumped lasers.

[0063] Gas lasers can include lasers such as helium-neon lasers, argon lasers, krypton lasers, xenon ion lasers, nitrogen lasers, carbon dioxide lasers, carbon monoxide lasers, or excimer lasers.

[0064] Chemical lasers can include lasers such as hydrogen fluoride lasers, deuterium fluoride lasers, COIL (chemical oxygen-iodine lasers), or Agil (all-gas phase iodine lasers).

[0065] Metal vapor lasers can include lasers such as: helium-cadmium (HeCd) metal vapor lasers, helium-mercury (HeHg) metal vapor lasers, helium-selenium (HeSe) metal vapor lasers, helium-silver (HeAg) metal vapor lasers, strontium vapor lasers, neon-copper (NeCu) metal vapor lasers, copper vapor lasers, gold vapor lasers, or manganese (Mn / MnCl2) vapor lasers. Rubidium or other alkali metal vapor lasers can also be used. Solid-state lasers can include lasers such as: ruby ​​lasers, Nd:YAG lasers, NdCrYAG lasers, Er:YAG lasers, neodymium YLF (Nd:YLF) solid-state lasers, neodymium-doped yttrium vanadate (Nd:YVO4) lasers, and neodymium-doped calcium yttrium oxyborate Nd:YCa4O(BO3). 3Or simply referred to as Nd:YCOB, neodymium glass (Nd: glass) laser, titanium sapphire (Ti: sapphire) laser, thulium YAG (Tm:YAG) laser, ytterbium YAG (Yb:YAG) laser, ytterbium:2O3 (glass or ceramic) laser, ytterbium-doped glass laser (rod, plate / sheet and fiber), holmium YAG (Ho:YAG) laser, chromium ZnSe (Cr:ZnSe) laser, cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), promethium-doped 147 phosphate glass (147Pm) +3 Solid-state lasers include glass-based lasers, chromium-doped gold-green sapphire (emerald green) lasers, erbium-doped and erbium-ytterbium co-doped glass lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, divalent samarium-doped calcium fluoride (Sm:CaF2) lasers, or F-centered lasers.

[0066] Semiconductor lasers may include laser medium types such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, GaInP, InGaAs, InGaAsO, GaInAsSb, lead salt, vertical cavity surface emission laser (VCSEL), quantum cascade laser, hybrid silicon laser, or combinations thereof.

[0067] Figure 2 The use of a high-speed optical valve, such as those disclosed herein, in an additive manufacturing system 200 is illustrated. A laser source 202 guides a laser beam through a laser preamplifier and / or amplifier 204 into a high-speed optical valve 206. After patterning, the light can be directed into a print bed 210. In some embodiments, thermal or laser energy from the laser source 202, the laser preamplifier and / or amplifier 204, or the high-speed optical valve 206 can be actively or passively transferred to a heat transfer device, a heat engine, a cooling system, and a beam storage field 208. The overall operation of the optical valve-based additive manufacturing system 200 can be controlled by one or more controllers 220, which can modify laser power and timing.

[0068] In some embodiments, various preamplifiers or amplifiers 204 may optionally be used to provide high gain to the laser signal, while optical modulators and isolators may be distributed throughout the system to reduce or avoid optical damage, improve signal contrast, and prevent damage to the lower energy portions of system 200. Optical modulators and isolators may include, but are not limited to, Pockels cells, Faraday rotators, Faraday isolators, acousto-optic reflectors, or volume Bragg gratings. Preamplifiers or amplifiers 204 may be diode-pumped or flash-lamp-pumped amplifiers and are configured in single-pass and / or multi-pass or cavity-type architectures. As will be understood, the term preamplifier is used herein to refer to amplifiers that are not thermally limited relative to the (larger) laser amplifier (i.e., they are smaller). Amplifiers will typically be positioned as the final unit in the laser system and will be the first module susceptible to thermal damage (including, but not limited to, thermal breakage or excessive thermal lensing).

[0069] Laser preamplifiers can include single-pass preamplifiers available in systems where energy efficiency is not a primary concern. For systems with higher energy efficiency, multi-pass preamplifiers can be configured to extract a significant amount of energy from each preamplifier 204 before moving to the next stage. The number of preamplifiers 204 required for a particular system is limited by system requirements and the available stored energy / gain in each amplifier module. Multi-pass preamplifiers can be implemented using angle multiplexing or polarization switching (e.g., using waveplates or Faraday rotators).

[0070] Alternatively, the preamplifier may include a cavity structure with a regenerative amplifier-type configuration. While such a cavity structure can limit the maximum pulse length due to typical mechanical considerations (cavity length), in some embodiments, a "white cell" cavity can be used. A "white cell" is a multi-pass cavity architecture in which a small angular deviation is added with each pass. By providing inlet and outlet paths, such a cavity can be designed to have a very large number of passes between the inlet and outlet, allowing for high gain and efficient use of the amplifier. An example of a white cell is a confocal cavity with a slightly off-axis injection beam and tilted mirrors, thus producing a ring pattern on the mirrors after multiple passes. The number of passes can be varied by adjusting the injection angle and the mirror angle.

[0071] The amplifiers also provide sufficient stored energy to meet the system's energy requirements, while supporting adequate thermal management so that they can operate at the system's required repetition rate, regardless of whether they are diode-pumped or flash-lamp-pumped. Both the thermal energy and laser energy generated during operation can be directed to the heat transfer device, heat engine, cooling system, and beam dump 208.

[0072] Amplifiers can be configured as single-pass and / or multi-pass or cavity architectures. Amplifiers can include single-pass amplifiers available in systems where energy efficiency is not a primary concern. For more energy-efficient systems, multi-pass amplifiers can be configured to extract a significant amount of energy from each amplifier before moving to the next stage. The number of amplifiers required for a particular system is limited by system requirements and the available stored energy / gain in each amplifier module. Multi-pass pre-amplification can be achieved through angle multiplexing, polarization switching (waveplates, Faraday rotators). Alternatively, amplifiers can include cavity structures with a regenerative amplifier-type configuration. As discussed with respect to preamplifiers, amplifiers can be used for power amplification.

[0073] In some embodiments, the thermal and laser energy generated during operation of system 200 can be directed to a heat transfer device, a thermal engine, a cooling system, and a beam dump 208. Alternatively or additionally, in some embodiments, the beam dump 208 may be part of a heat transfer system to provide useful heat to other industrial processes. In other embodiments, the heat may be used to power a thermal engine suitable for generating mechanical, thermoelectric, or electrical power. In some embodiments, waste heat may be used to raise the temperature of connecting components. It will be understood that laser flux and energy can be scaled in this architecture by adding more preamplifiers and amplifiers with appropriate thermal management and optical isolation. Performance can be tuned by increasing the pump rate or changing the cooling efficiency, thus allowing for the adjustment of the heat dissipation characteristics of the cooling system.

[0074] Figure 3 An additive manufacturing system 300 is shown that can accommodate a high-speed optical valve as described in this disclosure. Figure 3 As seen, the laser source and amplifier 312 may include a resonant-based optical valve and laser amplifier, as well as other components such as those previously described. Figure 3As shown, the additive manufacturing system 300 uses a laser capable of providing one-dimensional or two-dimensional guided energy as part of a laser patterning system 310. In some embodiments, one-dimensional patterning can be guided as linear or curved stripes, grating lines, spirals, or any other suitable form. Two-dimensional patterning can include separate or overlapping tiles, or images with varying laser intensity. Two-dimensional image patterns with non-square boundaries can be used, overlapping or interpenetrating images can be used, and the images can be provided by two or more energy patterning systems. The laser patterning system 310 uses a laser source and amplifier 312 to guide one or more continuous or intermittent energy beams toward a beam-shaping optics 314. After forming, if necessary, the beams are patterned by a laser patterning unit 316, which includes a transmission or reflection light valve, where typically some energy is guided to a waste energy processing unit 318. The waste energy processing unit can utilize heat provided by active cooling of the light valves.

[0075] Patterning energy is relayed from image repeater 320 to article processing unit 340, in one embodiment as a two-dimensional image 322 focused near bed 346. Bed 346 (with optional walls 348) may form a chamber to accommodate material 344 (e.g., metal powder) dispensed by material dispenser 342. Patterning energy directed by image repeater 320 may melt, smelt, sinter, merge, alter crystal structure, influence stress patterning, or otherwise chemically or physically alter the dispensed material 344 to form a structure with desired properties. Control processor 350 may be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate the operation of laser source and amplifier 312, beam shaping optics 314, laser patterning unit 316, and image repeater 320, as well as any other components of system 300. As will be understood, the connection can be wired or wireless, continuous or intermittent, and includes the ability to provide feedback (e.g., thermal heating can be adjusted in response to a sensed temperature).

[0076] In some embodiments, beam-shaping optics 314 may include various imaging optics to shape and guide one or more laser beams received from the laser source and amplifier 312 toward the laser patterning unit 316, in a manner that combines, focuses, diverges, reflects, refracts, homogenizes, modulates intensity, modulates frequency, or otherwise. In one embodiment, multiple beams, each with a different wavelength, may be combined using wavelength-selective mirrors (e.g., dichroic) or diffractive elements. In other embodiments, faceted mirrors, microlenses, and refractive or diffractive optics may be used to homogenize or combine multiple beams.

[0077] The laser patterning unit 316 may include static or dynamic energy patterning elements. For example, a laser beam may be blocked by a mask with fixed or movable elements. To increase the flexibility and ease of image patterning, pixel-addressable masking, image generation, or transmission may be used. In some embodiments, the laser patterning unit includes an addressable optical valve, which may be used alone or in combination with other patterning mechanisms to provide patterning. The optical valve may be transmissive, reflective, or use a combination of transmissive and reflective elements. The pattern may be dynamically changed using electrical addressing or optical addressing. In one embodiment, a transmissive optical addressable optical valve is used to rotate the polarization of light passing through the valve, wherein optically addressed pixels form a pattern defined by a light projection source. In another embodiment, a reflective optical addressable optical valve includes a write beam for changing the polarization of a read beam. In some embodiments, non-optically addressable optical valves may be used. These may include, but are not limited to, electrically addressable pixel elements, movable mirror or micromirror systems, piezoelectric or micro-actuated optical systems, fixed or movable masks, or shielding, or any other conventional system capable of providing high-intensity light patterning.

[0078] Waste energy processing unit 318 is used to dissipate, redirect, or utilize unpatterned energy passing through image repeater 320. In one embodiment, waste energy processing unit 318 may include passive or active cooling elements that remove heat from both the laser source, light valve and amplifier 312, and laser patterning unit 316. In other embodiments, waste energy processing unit may include a "beam dump field" to absorb any beam energy unused in defining the laser pattern and convert it into heat. In still other embodiments, beam shaping optics 314 may be used to recover waste laser beam energy. Alternatively or additionally, waste beam energy may be directed to article processing unit 340 for heating or additional patterning. In some embodiments, waste beam energy may be directed to an additional energy patterning system or article processing unit.

[0079] In one embodiment, a "switch station" optical system can be used. Switch station systems are suitable for reducing light waste in additive manufacturing systems caused by discarding unwanted light due to the pattern to be printed. A switch station involves the redirection of a complex pattern from its generation (in this case, a spatial pattern is given to the plane of a structured or unstructured beam) to its delivery through a series of switching points. Each switching point can optionally alter the spatial profile of the incident beam. Switch station optical systems can be used, for example, but not limited to, laser-based additive manufacturing techniques, where a mask is applied to the light. Advantageously, in various embodiments according to this disclosure, the discarded energy can be recovered either as homogenized light or as patterned light to maintain high power efficiency or high throughput. Furthermore, the discarded energy can be recovered and reused to increase the intensity for printing more difficult materials.

[0080] Image repeater 320 can receive patterned images (one-dimensional or two-dimensional) directly or via a switching station from laser patterning unit 316 and guide them toward article processing unit 340. Similar to beam-shaping optics 314, image repeater 320 can include optics for combining, focusing, diverging, reflecting, refracting, adjusting intensity, adjusting frequency, or otherwise shaping and guiding patterned light. Movable mirrors, prisms, diffractive optics, or solid-state optical systems that do not require substantial physical movement can be used to guide the patterned light. One of a plurality of lens assemblies can be configured to provide incident light with a magnification ratio, wherein the lens assembly has both a first set of optical lenses and a second set of optical lenses, and the second set of optical lenses is interchangeable from the lens assembly. Rotation of one or more sets of mirrors mounted on a compensation stage and a final mirror mounted on a construction platform stage can be used to guide incident light from the precursor mirror to a desired location. The translational movement of the compensation stage and the construction platform stage also ensures that the distance between the incident light from the forebody mirror and the article handling unit 340 is essentially equal to the image distance. In effect, this allows the beam delivery size and intensity for different materials to be rapidly varied between locations within the construction area, while ensuring high system availability.

[0081] Article handling unit 340 may include a walled chamber 348 and a bed 344 (collectively defining a construction chamber), and a material dispenser 342 for dispensing materials. The material dispenser 342 may dispense, remove, mix, provide gradations or variations in material type or particle size, or adjust the layer thickness of materials. Materials may include metals, ceramics, glass, polymer powders, other fusible materials capable of undergoing a thermally induced phase transition from solid to liquid and back to solid, or combinations thereof. The material may also include composites of fusible and non-fusible materials, where one or both components may be selectively targeted by an imaging relay system to melt the fusible component while the non-fusible material is left or subjected to evaporation / destruction / burning or other destructive processes. In some embodiments, a slurry, spray, coating, thread, strip, or sheet of material may be used. Unwanted material may be removed for single-use processing or recycling by using a blower, vacuum system, sweeping, vibration, shaking, tilting, or inverting the bed 346.

[0082] In addition to material handling components, the article handling unit 340 may include components for holding and supporting the 3D structure, mechanisms for heating or cooling the chamber, auxiliary or supporting optics, and sensors and control mechanisms for monitoring or regulating material or environmental conditions. The article handling unit may be wholly or partially supported by a vacuum or inert gas atmosphere to reduce unwanted chemical interactions and mitigate the risk of fire or explosion (especially with reactive metals). In some embodiments, various pure other atmospheres or mixtures of other atmospheres may be used, including those containing: Ar, He, Ne, Kr, Xe, CO2, N2, O2, SF6, CH4, CO, N2O, C2H2, C2H4, C2H6, C3H6, C3H8, i-C4H 10 C4H 10 ,1-C4H8, cic-2, C4H7, 1,3-C4H6, 1,2-C4H6, C5H 12 n-C5H 12 i-C5H 12 n-C6H 14 C2H3Cl, C7H 16 C8H 18 C 10 H 22 C 11 H 24 C 12 H 26 C 13 H 28 C 14 H 30 C 15 H 32 C 16 H 34 C6H6, C6H5-CH3, C8H 10 C2H5OH, CH3OH, iC4H8. In some embodiments, refrigerants or large inert molecules (including, but not limited to, sulfur hexafluoride) may be used. A closed atmosphere composition having at least about 1% He by volume (or density number) and a selected percentage of inert / non-reactive gases may be used.

[0083] In some embodiments, multiple article handling units or build chambers (each with a build platform for holding a powder bed) can be used in conjunction with multiple optomechanical components arranged to receive and guide one or more incident energy beams into the build chambers. Multiple chambers allow for the simultaneous printing of one or more print jobs within one or more build chambers. In other embodiments, removable chamber sidewalls can simplify the removal of printed objects from the build chambers, allowing for rapid exchange of powder material. The chamber may also be equipped with an adjustable process temperature controller. In still other embodiments, the build chamber can be configured as a removable printer cartridge positioned near laser optics. In some embodiments, the removable printer cartridge may include powder or support for a detachable connection to a powder supply. After a manufacturing process, the removable printer cartridge can be removed and replaced with a new printer cartridge.

[0084] In another embodiment, one or more article handling units or build chambers may have build chambers maintained at a fixed height, while the optics are vertically movable. The distance between the final optics of the lens assembly and the top surface of the powder bed can be managed to be substantially constant by rotating the final optics upward by a distance equivalent to the powder layer thickness, while maintaining the build platform at a fixed height. Advantageously, large and heavy objects can be manufactured more easily compared to a vertically moving build platform because precise micron-level movement of the constantly changing mass of the build platform is not required. Typically, build chambers intended for metal powders with volumes greater than about 0.1–0.2 cubic meters (i.e., greater than 100–200 liters or greater than 500–1,000 kg) will benefit most from maintaining the build platform at a fixed height.

[0085] In one embodiment, a portion of the powder bed layer may be selectively melted or fused to form one or more temporary walls outside the fused portion of the powder bed layer, thereby incorporating another portion of the powder bed layer on the build platform. In selected embodiments, fluid channels may be formed within one or more first walls to achieve improved thermal management.

[0086] In some embodiments, the additive manufacturing system may include an article handling unit or a build chamber with a build platform supporting a powder bed that can be tilted, inverted, and rocked to substantially separate the powder bed from the build platform in a hopper. The powder material forming the powder bed can be collected in the hopper for reuse in subsequent printing jobs. The powder collection process can be automated, and vacuum or gas jet systems are also used to assist in powder expulsion and removal.

[0087] In some embodiments, the additive manufacturing system can be configured to easily handle parts longer than the available build chambers. A continuous (long) part can sequentially advance from a first zone to a second zone in the longitudinal direction. In the first zone, selected particles of granular material can be combined. In the second zone, uncombined particles of granular material can be removed. A first portion of the continuous part can advance from the second zone to a third zone, while the last portion of the continuous part is formed within the first zone, and the first portion remains in the same position in the lateral and transverse directions as it occupied in the first and second zones. In practice, additive manufacturing and cleaning (e.g., separation and / or recycling of unused or uncombined granular material) can be performed in parallel (i.e., simultaneously) at different locations or zones on the part conveyor without requiring a stop for the removal of granular material and / or parts.

[0088] In another embodiment, additive manufacturing capabilities can be enhanced by using a closed enclosure that restricts the exchange of gaseous substances between the interior and exterior of the enclosure. An airlock provides the interface between the interior and exterior; the interior has multiple additive manufacturing chambers, including those supporting powered bed melting. A gas management system maintains gaseous oxygen within the enclosure at or below the limiting oxygen concentration, increasing the types of powders that can be used in the system and the flexibility of processing.

[0089] In another manufacturing embodiment, capability can be increased by including an article handling unit or build chamber within the enclosure, the build chamber being capable of manufacturing parts weighing 2000 kg or more. A gas management system can maintain gaseous oxygen within the enclosure at a concentration below atmospheric levels. In some embodiments, a wheeled vehicle can transport parts from inside the enclosure through an airlock (because the airlock acts as a buffer between the gaseous environments inside and outside the enclosure) and transport the parts to a location outside both the enclosure and the airlock.

[0090] Other manufacturing embodiments involve collecting powder samples from a powder bed in real time. An intake system is used for the in-process collection and characterization of the powder samples. Collection can be performed periodically, and the results of characterization lead to adjustments in the powder bed melting process. The intake system can optionally be used for one or more of the following: evaluation, process regulation, or actions, such as changing printer parameters or verifying the correct use of licensed powder materials.

[0091] Another improvement to the additive manufacturing process is described, which can be provided by using a manipulator device, such as a crane, lifting platform, robotic arm, or similar device that allows manipulation of parts that are difficult or impossible for humans to move. The manipulator device can grasp various permanent or temporary additional manufacturing manipulation points on the part, enabling the part to be repositioned or manipulated.

[0092] The control processor 350 can be connected to control any component of the additive manufacturing system 300 described herein, including lasers, laser amplifiers, optics, thermal control, build chambers, and manipulator devices. The control processor 350 can be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operation. Various sensors, including imagers, light intensity monitors, and heat, pressure, or gas sensors, can be used to provide information used in control or monitoring. The control processor can be a single central controller, or alternatively, it can include one or more independent control systems. The controller processor 350 is provided with an interface that allows input of manufacturing instructions. The use of various sensors allows for various feedback control mechanisms to improve quality, manufacturing throughput, and energy efficiency.

[0093] Figure 4 An embodiment of a manufacturing system supporting the use of high-speed optical valves suitable for additive or subtractive manufacturing is illustrated. In this embodiment, flowchart 400 illustrates an example of a manufacturing process supported by the described optics and mechanical components. In step 402, material is positioned in a bed, chamber, or other suitable support. The material may be a sheet of metal laser-cut using subtractive manufacturing techniques, or a powder that can be melted, fused, sintered, induced to alter its crystal structure, influence its stress mode, or otherwise chemically or physically modified by additive manufacturing techniques to form a structure with desired properties.

[0094] In step 404, the unpatterned laser energy is emitted by one or more energy emitters, including but not limited to solid-state or semiconductor lasers, and then amplified by one or more laser amplifiers. In step 406, the unpatterned laser energy is shaped and modified (e.g., intensity modulation or focusing). In step 408, the unpatterned laser energy is patterned by a high-speed optical valve, wherein the energy that does not form a pattern is processed in step 410 (this may include using, for example, regarding...). Figure 2 and Figure 3 The disclosed beam dump provides a conversion to waste heat (as a recycling of patterned or unpatterned energy, or waste heat generated in step 404 by cooling the laser amplifier). In step 412, patterned energy, now forming a one-dimensional or two-dimensional image, is redirected to the material. In step 414, the image is applied to the material, either subtractively or additively, to build part of a 3D structure. For additive manufacturing, these steps (ring 416) can be repeated until the image (or different and subsequent images) has been applied to all necessary areas of the top layer of the material. When the energy application to the top layer of the material ends, a new layer (ring 418) can be applied to continue building the 3D structure. These processes cycle until the 3D structure is complete, at which point excess material can be removed or recycled.

[0095] Figure 5 This is one embodiment of an additive manufacturing system, which includes a high-speed optical valve and switching station system that enables the reuse of patterned two-dimensional energy. The additive manufacturing system 520 has an energy patterning system with a laser and amplifier source 512 that guides one or more continuous or intermittent laser beams toward a beamforming optics 514. Excess heat can be transferred to a waste energy processing unit 522, which may include, as described above... Figure 2 , Figure 3 and Figure 4 The disclosed active light valve cooling system. After forming, the beam is two-dimensionally patterned by an energy patterning unit 530 based on resonant material, where some energy is typically directed to a waste energy processing unit 522. The patterning energy is relayed by one of a plurality of image repeaters 532 toward one or more article processing units 534A, 534B, 534C, or 534D, typically as a two-dimensional image focused near a movable or fixed-height bed. This bed may be located within a cylinder including a powder hopper or similar material dispenser. The patterned laser beam guided by the image repeater 532 can melt, ablate, sinter, merge, alter crystal structure, influence stress patterns, or otherwise chemically or physically alter the dispensed material to form a structure with desired properties.

[0096] In this embodiment, the waste energy processing unit has multiple components to allow for the reuse of waste patterned energy. Coolant fluid from the laser amplifier and source 512 can be directed to one or more of the generator 524, the heating / cooling thermal management system 525, or the energy storage field 526. Furthermore, repeaters 528A, 528B, and 528C can respectively transfer energy to the generator 524, the heating / cooling thermal management system 525, or the energy storage field 526. Optionally, repeater 528C can direct patterned energy to image repeater 532 for further processing. In other embodiments, patterned energy can be directed by repeater 528C to repeaters 528B and 528A for insertion into a laser beam provided by the laser and amplifier source 512. Reuse of patterned images can also be achieved using image repeater 532. Images can be redirected, inverted, mirrored, sub-patterned, or otherwise transformed for distribution to one or more article processing units 534A-534D. Advantageously, the reusability of patterned light can improve the energy efficiency of additive manufacturing processes and, in some cases, increase the energy intensity of the pointing bed or reduce manufacturing time.

[0097] Many modifications and other embodiments of the invention will arise for those skilled in the art upon which the teachings presented in the foregoing description and the associated drawings will come to mind. Therefore, it should be understood that this disclosure is not limited to the specific embodiments disclosed, and that modifications and other embodiments are considered to be included within the scope of the appended claims. It should also be understood that other embodiments of the invention may be practiced without the elements / steps specifically disclosed herein.

Claims

1. An additive manufacturing system, comprising: A first light source generates a first laser writing beam with a first flux; A second light source generates a second laser readout beam with a second flux, the second flux being greater than the flux of the first laser write beam; as well as A 2D patternable light valve with a reflective structure, the reflective structure being patterned by a first laser writing beam to reflect light from a second laser reading beam, thereby generating a patterned laser beam. The reflective structure includes a mirror, a photoconductor layer, a first alignment layer and a second alignment layer, and a linear electro-optic layer. The first alignment layer and the second alignment layer are deposited on opposite sides of the linear electro-optic layer to set the orientation of the linear electro-optic layer. The first alignment layer interfaces with a first side of the reflector, and the photoconductor layer interfaces with a second side of the reflector. The linear electro-optic layer is configured to pattern light from the second laser readout beam that enters and exits the reflective structure through the first alignment layer and the second alignment layer, based on the intensity pattern of the first laser writing beam.

2. The additive manufacturing system according to claim 1, wherein, The 2D patternable light valve also includes a transparent conductive oxide layer deposited on the photoconductor layer.

3. The additive manufacturing system according to claim 1, wherein, The photoconductor layer is deposited on the second side of the mirror.

4. The additive manufacturing system according to claim 1, wherein, The 2D patternable light valve guides unpatterned light into at least one of the beam storage field or switch station system.

5. An additive manufacturing system, comprising: Electron writing beam; Laser reading beam; as well as A 2D patternable light valve with a reflective structure, the reflective structure being patterned by the electronically written beam to reflect light from the laser readout beam, thereby generating a patterned laser beam. The reflective structure includes a mirror, a structured via layer, a first alignment layer and a second alignment layer, and a linear electro-optic layer. The first alignment layer and the second alignment layer are deposited on opposite sides of the linear electro-optic layer to set the orientation of the linear electro-optic layer. The first alignment layer interfaces with a first side of the reflector, and the structured via layer interfaces with a second side of the reflector. The linear electro-optic layer is configured to pattern light from the laser readout beam that enters and exits the reflective structure through the first alignment layer and the second alignment layer, based on charged pixels defined by the electronic writing beam in the structured via layer.

6. The additive manufacturing system according to claim 5, wherein, The 2D patternable light valve also includes a secondary emission gate.

7. The additive manufacturing system according to claim 5, wherein, The 2D patternable light valve guides unpatterned light into at least one of the beam storage field or switch station system.

8. An additive manufacturing system, comprising: Electron beam array; Laser reading beam; as well as A 2D patternable light valve with a reflective structure, the reflective structure being patterned by the electron beam array to reflect light from the laser readout beam, thereby generating a patterned laser beam. The reflective structure includes a mirror, a structured via layer, a first alignment layer and a second alignment layer, and a linear electro-optic layer. The first alignment layer and the second alignment layer are deposited on opposite sides of the linear electro-optic layer to set the orientation of the linear electro-optic layer. The first alignment layer interfaces with a first side of the reflector, and the structured via layer interfaces with a second side of the reflector. The linear electro-optic layer is configured to pattern light from the laser readout beam that enters and exits the reflective structure through the first alignment layer and the second alignment layer, based on charged pixels defined by the electron beam array in the structured via layer.

9. The additive manufacturing system according to claim 8, wherein, The 2D patternable light valve also includes multi-row and multi-column addressable electronic transmitters.

10. The additive manufacturing system according to claim 8, wherein, The electron beam array also includes a plurality of electron beam array drivers, which are positioned to receive electrons from an electron emitter.

11. The additive manufacturing system according to claim 8, wherein, The 2D patternable light valve guides unpatterned light into at least one of the beam storage field or switch station system.

12. An additive manufacturing system, comprising: Self-emitting display; Laser reading beam; as well as A 2D patternable light valve with a reflective structure, patterned by the self-emitting display to reflect light from the laser readout beam, thereby generating a patterned laser beam. The reflective structure includes a mirror, a photoconductor layer, a first alignment layer and a second alignment layer, and a linear electro-optic layer. The first alignment layer and the second alignment layer are deposited on opposite sides of the linear electro-optic layer to set the orientation of the linear electro-optic layer. The first alignment layer interfaces with a first side of the reflector, and the photoconductor layer interfaces with a second side of the reflector. The linear electro-optic layer is configured to pattern the light from the laser readout beam that enters and exits the reflective structure through the first alignment layer and the second alignment layer, based on the intensity pattern of the light from the self-emitting display.

13. The additive manufacturing system according to claim 12, wherein, The 2D patternable light valve also includes a microlens array positioned to guide light from the self-emitting display toward the reflective structure.

14. The additive manufacturing system according to claim 12, wherein, The self-emitting display includes at least one of an OLED array, an LED array, or a micro-LED display.

15. The additive manufacturing system according to claim 12, wherein, The 2D patternable light valve guides unpatterned light into at least one of the beam storage field or switch station system.

Images