Structured preform for thermal drawing

Abstract

To provide a structured preform for thermal drawing.SOLUTION: A device according to the present invention is capable of generating a multi-layer stack of sheets that can be attached to a slab-shaped preform for thermal drawing (heating stretching). The sheet may include a sub-layer. Stacking the sub-layered sheets results in accumulation of layers in the final fabricated preform. The stacking process may use mechanical translation and conveyance system to support placement of the sheets and fabrication of the stack.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to structured preforms for thermal drawing.

[0002] REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 848,243 (Attorney Docket No. 16030-37), filed May 15, 2019, which is incorporated by reference in its entirety. This application also claims priority to U.S. Provisional Patent Application No. 63 / 024,892 (Attorney Docket No. 16030-56), filed May 14, 2020, which is incorporated by reference in its entirety. [Background technology]

[0003] Optical materials (or optical media) have become widespread as a result of rapid advancements driven by strong customer demands in display technology, energy efficiency, and various other optical elements. As an example, millions of square meters of optical filters are required for flat and flexible screen displays throughout the world. Improvements in optical media quality and production speeds will continue to drive demand. Summary of the Invention

[0004] According to one aspect of the present invention, there is provided an apparatus comprising: an extrusion die having an extrusion output, the extrusion output being in the form of a slit to produce the membrane; a preform assembly platform; a translation stage, the movement of which creates relative motion between the extrusion output and the preform assembly platform; An apparatus is provided having controller circuitry communicatively coupled to the translation stage, the controller circuitry sending motion commands to the translation stage to position the preform build platform so that a current film obtained by the extrusion die is layered on top of a previous film obtained by the extrusion die to create a preform stack.

[0005] According to another aspect of the present invention, there is provided an apparatus comprising: a seat reservoir; a preform assembly platform; an assembly robot arm having a seat grip at a distal end thereof; a press having a heated press plate; A conveyor and and controller circuitry communicatively coupled to the robotic arm, the conveyor, and the press, the controller circuitry comprising: issuing pick and place commands to a robotic arm to select sheets from a sheet reservoir and build a vertical stack of sheets on a preform assembly platform; After sending the pick and place command, a transport command is issued to the conveyor to translate the preform assembly to the preform assembly platform leading to the press; and An apparatus is provided that is configured to send a conveying command and then send a press command to a press to apply heat and pressure to the vertical stack of sheets.

[0006] According to yet another aspect of the present invention, there is provided a method, comprising the steps of: extruding the film through an extrusion die to an extrusion output; and translating the preform assembly platform relative to the extrusion output in coordination with the extrusion, wherein the film falls onto the preform stack on the preform assembly platform, the film forming a current layer of the preform stack on top of the previous layer of the preform stack, the previous layer also having been extruded through the extrusion die.

[0007] According to yet another aspect of the present invention there is provided a method comprising the step of using any of the above described devices.

[0008] According to yet another aspect of the present invention, there is provided a manufacturing method implementing any of the above-described apparatus and / or methods for making a preform, comprising the steps of: Optionally, the method is characterized in that the preform is an optical filter preform. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an exemplary apparatus for making a preform. [Figure 2] 2 shows the corresponding logic circuitry for the operation of the preform manufacturing apparatus of FIG. 1; [Figure 3] FIG. 2 is another view of the device of FIG. 1. [Figure 4] FIG. [Figure 5] FIG. 10 is another enlarged view of the top roller arm. [Figure 6] FIG. 10 is yet another enlarged view of the top roller arm. [Figure 7] FIG. 1 illustrates an exemplary apparatus for extrusion. [Figure 8] FIG. 1 illustrates an exemplary technique for extrusion. [Figure 9] 8 illustrates an example corresponding logic circuit for operation of the example extrusion device of FIG. 7. [Figure 10] FIG. 8 is another view of the device of FIG. 7. [Figure 11] FIG. 8 is yet another view of the device of FIG. 7. [Figure 12] FIG. 8 is yet another view of the device of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0010] In various systems for coextrusion to fabricate multilayer optical films, finite friction on the material flow from the internal walls of the coextrusion feed blocks and layer multiplier units within the coextrusion line results in layer distortions that can adversely affect the integrity and consistency of the thin film layers. This can, in some cases, adversely affect the optical performance of the final fabricated optical component. Systems using self-assembling polymers and polymer-stabilized chiral liquid crystals are useful. However, self-assembly can pose challenges in fabricating systems with tens, hundreds, and / or thousands of layers. Various modifications to the above techniques may be implemented to achieve a variety of structured layers, up to tens, hundreds, or even thousands of layers, and high levels of optical quality during fabrication. For example, as described below, coextrusion, stack and draw, and / or other techniques can be used to create first-stage slab-like preforms, which are then heated and stretched to create the final fabricated optical component.

[0011] In various systems, slab-like preforms can be stretched into medium-sized films or sheets in a first stretching stage. These sheets can be stacked into multilayer, second-stage slab-like preforms for stretching into layered nano- or micro-scale sheets. For example, the structured film (after multi-stage stretching) can be a multilayer stack of 100 quarter-wave layers (50 bilayers) of two interleaved materials with different refractive indices. In an example, a thick preform with two layers, total thickness 25 mm, can be first assembled so that the ratio of the two layers is inversely proportional to the ratio of the refractive indices of the two materials. The two-layer preform can be assembled from thermally and chemically compatible materials so that they bond together under heat and pressure (at a temperature slightly above the softening and / or melting points of the materials) or by other adhesive methods. This exemplary two-layer preform can then be stretched 250 times to form a 0.1 mm thick two-sublayer film. Fifty such two-sublayer films of identical thickness can then be stacked on top of each other under heat and pressure to create a 100-layer second-stage preform with a total multilayer thickness of 5 mm. These multilayers can then be embedded in a jacket layer, similar to photonic crystal fiber (PCF) canes that are often embedded in outer tubes. This second-stage preform can then be stretched 500 times so that each internal bilayer is now 200 nm, corresponding to a quarter-wave Bragg reflector in the infrared range of the spectrum (wavelength dependent on the refractive index of the layers). This technique can be extended in various ways beyond the above example. For example, this technique can be used with first-stage films of more than two layers or more than two materials. In one example, this technique can be used to create filters with layer thickness ratios other than those available as quarter-wave stacks, for example, to form long-period gratings, half-wave, full-wave, or subwavelength metamaterials.

[0012] Additionally or alternatively, first-stage films (e.g., first-stage films forming sublayers within a film to form a preform stack) can be produced by techniques other than stretching. Illustratively, a few-layer first-stage film can be produced by a coextrusion process. As an example, a coextrusion feed block and die can be used for up to 12 sublayers of up to four different materials (e.g., from four different feedline connection inputs). The die can support thickness control for each individual die slit, allowing for independent customization of each of the multiple sublayers within the film (each sublayer is then stacked to form a preform). In some cases, a ratio of 3 can be achieved between the minimum and maximum sublayer thicknesses. The coextruded films or sheets can then be assembled into second-stage preforms for thermal drawing of multilayer preforms.

[0013] Thereafter, various techniques and architectures are described for providing and fabricating such structured preforms to enable drawing into structured films or sheets.

[0014] In various embodiments, a stack assembly device may be used to assemble the multi-layer preforms prior to thermal drawing.

[0015] In the first stage, various sheets with different thicknesses, different materials, different sublayer configurations, or other characteristics can be stored in a sheet reservoir. The sheets can be of a single length and width (even sheets of non-uniform thickness) so that they can be combined into a coplanar stack with flat sides. In some cases, a flat surface on a robot arm or a sheet sleeve on an assembly platform can be used to press the sheets coplanar. In some cases, the sheet sleeve can be removable from the assembly platform so that it can be removed before the sheets are pressed to achieve adhesion. The sheets can be brought forward by a pick-and-place robot arm equipped with suction lift grips (or other stacking systems, such as multiple parallel conveyor tracks with laterally running collection platforms). The sheets can then be placed by a sheet cleaning system including a dust pickup roller assembly, ionized pressure air cleaning, or other cleaning system. However, the need for cleaning after pick-and-place sequencing can depend on the dust and / or moisture levels in the sheet reservoir. Thus, in some cases, sheet cleaning may not be performed in the system or may be skipped when a measurement condition (eg, air quality condition, atmospheric dust level, or other condition) is met.

[0016] In the second stage, the sheets can be assembled into preforms. A pick-and-place robotic arm (or a second post-cleaning stacking system) can place the sheets selected and ordered in the first stage onto the preform assembly platform. Illustratively, a series of suction arms are aligned vertically or horizontally in a straight line so that they hold and move the first edge of the cleaned sheet as it exits the cleaning segment. The last of the arms can align the sheet in two horizontal directions (e.g., length and width) to a precise position on the preform assembly platform (or the incomplete preform being assembled). In some cases, the preform platform can have a vertical translation stage to bring the top surface of the preform being assembled to a height selected for the pick-and-place system to place the next sheet.

[0017] In this example, two arms (in some cases, separate and / or parallel) may be used. In the example, the top arm has a flexible cleaning roller and the bottom arm has a vacuum suction bar. The two arms then move horizontally along the length of the sheet. This process applies a downward vertical pressure force to the sheet to clean the top surface while removing any trapped air. The vacuum bar further aids in the dust / air removal process. In this example, the pick and place system may move arms or other obstacles out of the way to allow the two arms unimpeded travel across the stack.

[0018] Once the preform stack is assembled, a third pick and place system (e.g., a robotic arm, conveyor system, or other pick and place system) can transfer the preforms into a vacuum chamber that includes heated top and bottom plates that sandwich the preform stack and can apply a controlled pressure under vacuum.

[0019] Referring now to Figure 1, an exemplary apparatus 100 for preform fabrication is shown. The apparatus 100 includes a preform assembly platform 105, a sheet reservoir 110, a pick and place system 120, a cleaning system 130, a conveyor 140, and a press 150. Referring also to Figure 2, corresponding logic circuitry 200 for operation of the preform fabrication apparatus is shown. The logic circuitry 200 may be embodied on controller circuitry.

[0020] For further explanation, reference is also made to FIG. 3, which is another view of the device 100.

[0021] The sheet reservoir 110 may include a carousel 112 with multiple bins 114 of sheets (e.g., as shown in the example apparatus 100 of FIG. 1). In various embodiments, the sheet reservoir may be embodied by various sheet storage and dispensing systems. For example, the sheet reservoir 110 may include multiple bins 114, each containing a different type of sheet. In some cases, the bins may be arranged in an array. For example, the array may have defined locations for specific sheet types. In this way, the pick-and-place system can correlate bin locations with sheet types. In this way, a specific stacking order (e.g., the order in which sheets are placed in a preform stack) may be implemented by sequentially removing sheets from specific locations in the array.

[0022] In some embodiments, the sheet reservoir may have bins containing sheets in a pre-arranged stacking order. For example, sheets may be loaded into the bins of the sheet reservoir in the order (or in reverse order) in which the sheets will be arranged in the preform stack. The stacking order may include a repeating pattern, an alternating pattern, a sequence pattern (e.g., a diffraction grating pattern), a randomized pseudorandomized pattern, or other patterns oriented toward the optical elements.

[0023] In some implementations, the reservoir may have an input conveyor belt onto which the sheets are stacked. In some cases, the sheets may arrive in a stacking order on the conveyor belt.

[0024] In some implementations, a carousel may be used. In some cases, the carousel may be vertical or horizontal. In some cases, multiple parallel carousels may be used (e.g., in a laterally traveling pick-and-place system that travels between carousels to collect various sheets in stacking order).

[0025] In some cases, multiple conveyor tracks may be used, for example, with different types of sheets on different tracks, and a side-traveling pick-and-place system may be used to collect the sheets from the different tracks in stacking order.

[0026] The example pick-and-place system 120 may include a robotic arm 122 having a sheet gripper 124 at its distal end that can receive commands from a logic circuit 200 to stack sheets from the sheet reservoir 110 onto the preform assembly platform 105 in stacking order (202). In various systems, the sheet gripper may include a suction cup system, a clamp, a static cling system, or other system for gripping the sheets. At the time of assembly of the preform stack 101, the cleaning system 130 may be co-located with the preform assembly platform 105. In some cases, the preform assembly platform 105 may be located at the output of the cleaning system 130. In some cases, the preform assembly platform 105 may include a tray that can be conveyed by a belt and / or picked up by a robotic arm that can transport the stack as a unit before the sheets stick to each other. In some cases, the pick and place system may include a movable plane to press the sides of the sheet stack flat to ensure the sheets are properly aligned.

[0027] An example cleaning system 130 may include, for example, the two-arm system described above. For additional explanation, please also refer to Figures 4-6, which show enlarged views of the top roller arm 132. In some cases, the cleaning system may include ionized air pressure cleaning, a washing system (using a cleaning fluid, such as alcohol or other fluids), or other cleaning systems.

[0028] After assembling the preform stack, the conveyor system 140 may receive commands sent by the logic circuit 200 to transport the preform stack to the press 150 (204). The conveyor system may include a conveyor belt. Additionally or alternatively, the conveyor system 140 may include a robotic arm or another pick-and-place system.

[0029] When the preform stack is positioned within the press 150, the logic circuit 200 can send press commands to the stack to apply pressure (e.g., with the top and / or bottom press plates) to the preform stack (206). In some cases, the press commands can further include commands to apply heat (e.g., to heat the preform stack to a layer bonding temperature). The layer bonding temperature can include a temperature at which adjacent sheets adhere and / or fuse to one another. In some cases, the bonding temperature can be selected to be just above the softening temperature (for the sheet material) at which adjacent sheets can deform and adhere to one another. In some cases, the bonding temperature can be above the melting point (for the sheet material and / or a subset of the sheet material) at which adjacent sheets can adhere to one another by melting (or partial melting) and re-solidifying (e.g., freezing). In some embodiments, the press commands can further include commands to evacuate the press chamber to allow pressurization to occur under vacuum (or under heat and vacuum).

[0030] As mentioned above, the coextruded first stage films may be extruded directly on top of each other on a preform assembly platform.

[0031] Co-extruders are capable of producing high quality membranes containing multiple layers, each tens of micrometers thick. The technology described herein uses a co-extrusion process to produce first-stage membranes that are laid directly on top of each other to produce a multi-layer preform, which is then stretched into a thin film filter.

[0032] The coextrusion apparatus may have multiple extrusion lines for producing a multi-material first-stage film with one or more extruder feed lines for each of the materials. The multiple materials are combined and then forced into a slit die designed to force the streams of materials together into a stream containing at least one layer of each material. The coextrusion die may feed the multiple input materials into up to 12 different layers. In some embodiments, the size of the opening of each slit is adjustable by moving a lip between the slits to adjust the relative flow rates of the materials and, therefore, their relative thicknesses.

[0033] In this configuration for assembling multi-layer preforms, the slit adjustments may be motorized so that the slit openings and their relative dimensions can be adjusted based on commands from control circuitry. In some cases, the relative dimensions may comprise part of the preform specifications, which may further include layer sequence and / or other characteristics.

[0034] In a coextrusion apparatus, once the multi-sublayer film exits the die, it may pass through multiple rollers, including cooling rollers, to roll the film.

[0035] The extruded multi-sublayer film may be laid on top of a preform assembly platform or over an incomplete preform during assembly.

[0036] In various systems, the preform assembly platform may move along one or more axes, e.g., one longitudinal horizontal and one vertical axis, to support horizontal layer placement and vertical stacking. The vertical position may be adjusted so that the die exit is located a short distance from the top surface of the incomplete preform being assembled (or for the first layer, assembly platform). For each layer added to the preform, the preform platform may be shifted vertically to maintain the same extrusion output-to-top layer distance for each additional layer. The die temperature may be adjusted so that the extruded material is rigid enough at the exit not to deform or change thickness, yet still soft enough to adhere to the top surface of the preform during assembly. The preform assembly may also be located in an enclosure that provides a warm background temperature to facilitate bonding. This enclosure may additionally or alternatively provide a vacuum so that the layers tend to settle without interlayer air bubbles.

[0037] A roller can be fixed against the extrusion die to apply normal pressure to the film (slight, e.g., enough pressure to remove air bubbles or other deformations in the softened material). A vacuum bar can be (additionally or alternatively) utilized to remove gas and / or dust particles, thereby aiding in adhesion of the layers without deformation and debris. In some cases, adjusting the distance from the top roller to the die output, the roller temperature, and the normal pressure applied by the roller can minimize deformation of the film as it is attached to the top of the preform.

[0038] As mentioned above, multilayer extrusion dies allow for thickness control of the die slit and thus the membrane's inner sublayers. The extrusion rate can be used to control the thickness of the extruded sheet without changing the inner thickness ratio within the sheet. Thus, the sheet thickness and / or the inner sublayer thickness ratio can be dynamically adjusted layer by layer as the preform is being assembled.

[0039] Referring now to FIG. 7 , an exemplary apparatus 700 for extrusion is shown. The apparatus includes an extrusion die 710 with an extrusion output 712 and an extrusion input 714 connected to a material feed line 720. A roller 760 is attached to the extrusion output 712. The apparatus 700 further includes a preform assembly platform 730 and a translation stage 740. An enclosure 750 encloses portions of the apparatus 700, including the preform assembly platform 730 and the extrusion output 712. With continued reference to FIG. 7 , the following description also refers to FIG. 8 , which illustrates an exemplary complementary technique 800 for making preforms using extrusion, and the following description also further refers to FIG. 9 , which illustrates an exemplary corresponding logic circuit 900 for operation of the exemplary extrusion apparatus 700.

[0040] For further explanation, reference is now made to Figures 10-12, which show different views of device 700.

[0041] The extrusion die 710 may extrude material through an extrusion output 712 to produce a film (804). In various embodiments, the extrusion output 712 may be in the form of a slit. Material may be fed to the extrusion output 712 via an extrusion input 714. In some cases, the extrusion input may be located inside the extrusion die 710. In some cases, multiple extrusion inputs (whether internal or external) may be connected to a single feed line providing the same material or multiple feed lines providing similar materials. In some cases, different inputs may be connected to different feed lines providing different materials. In some cases, the extrusion die may have up to 12 inputs to support 12 sublayers in the extruded film, where the films become the layers of the produced preform. In some embodiments, logic circuitry 900 may send extrusion commands (902) that control the flow rate and / or extrusion speed. In some cases, the extrusion commands may include commands to adjust extrusion system parameters, such as apertures, to control relative sublayer thickness. In various embodiments, the extruded film may range in thickness from less than 10 microns to over 1000 microns. In some cases, the extruded film may be 300-400 microns thick.

[0042] In various embodiments, the material in the delivery line includes a polymer, such as a liquid crystal polymer or other polymer material, glass, metal, or other material for fabricating optical filters and / or other optical elements.

[0043] To extrude a film, the extrusion die can extrude material from one or more extrusion inputs and through channels to an extrusion output. In some cases, where multiple inputs are provided, the channels can push materials from different streams into a single stream for the output. Thus, where the inputs have heterogeneous materials, the combined stream can be composed of multiple materials.

[0044] In various embodiments, the multiple materials may be arranged in a pattern, such as an alternating pattern (where odd-numbered layers have one material and even-numbered layers have a different second material). Repeating, sequential, or other patterns are possible. In some cases, the layers may be in a selected order (e.g., by an operator) or a random / pseudo-random order. In the case of several bi-materials, a subset of the underlayers may be selected to have the first material, and a complementary subset (e.g., the remaining underlayers in the film are not part of the subset) may be selected to have the second material.

[0045] The translation stage 740 can position the preform platform 730 so that a film is laid down on top of the preform stack forming the current layer 713 of the preform stack (806). The top of the preform stack is formed by the previous layer 715. The current layer 713 is the layer currently being extruded (as a film), and the previous layer 715 includes layers previously extruded and laid down on the preform stack. The translation stage moves the preform stack so that the current layer covers the preform stack (e.g., end to end). The logic circuit 900 sends translation commands to the translation stage 740 to cause the translation stage movements described herein (904).

[0046] For example, the translation stage may run horizontally (eg, in one horizontal direction) from a layer start point to a layer end point.

[0047] When a layer endpoint is reached, extrusion may terminate / halt to form an end of the current layer. In some cases (e.g., provided in extrusion die 710), the current layer 713 is cut to separate it from the extrusion output 712. The cutter may include a cutting edge or blade that can shear the film, a cutting laser that ablates, melts, and / or burns to cause separation, a heater, or another cutting device to separate the film from the current layer at the extrusion output. The cutter may be controlled by a cutting command (906).

[0048] After reaching the layer endpoint and separating the film at the extrusion output from the current layer, the translation stage 740 can step vertically downward (e.g., by the thickness of the just-completed current layer 713) and return to the laser start point. The example apparatus 700 can then resume extrusion to produce a new current layer.

[0049] In various embodiments, the apparatus 700 can include a roller 760 that can exert vertical downward pressure on the current layer 713 while it is being laid to remove any deformities / air bubbles and help adhere the current layer 713 to the previous layer 715 on top. In some cases, the vertical distance between the bottom of the roller 760 and the extrusion output can be adjusted (manually and / or dynamically (908), e.g., by roller command) to control the level of pressure exerted. Additionally or alternatively, the horizontal distance can likewise be adjustable to control where the vertical pressure on the extrusion output is exerted relative to the extrusion output. In some cases, the vertical / horizontal positioning can be selected to eliminate / minimize / reduce deformities or incomplete interlayer adhesion. In some cases, the roller 760 can be heated to a layer adhesion temperature that aids in interlayer adhesion. In some cases, the heating for the interlayer bonding can be adjusted by the extrusion die 710, for example, so that the film is at the temperature used for the interlayer bonding when it exits at the extrusion output.

[0050] In various embodiments, the extrusion output and preform platform may be enclosed (802) within an enclosure 750 or covered by a dust shield. In some cases, the enclosure 750 may be moisture-proof, dust-proof, and / or airtight. In some cases, the enclosure may be sealed to support a low, medium, and / or high vacuum. A vacuum pump 752 may be used to evacuate the enclosure. The enclosure 750 may (alternatively or additionally) include a heater or heaters to heat the enclosure to a layer bonding temperature. The logic circuit 900 may send enclosure commands to control temperature and / or vacuum conditions within the enclosure (910).

[0051] The above description relates to optical materials, devices, and systems. The term "optical" refers to visible light, infrared light, ultraviolet light, and x-rays, as well as terahertz radiation and other radiation bands used in imaging, detection, or other optical applications.

[0052] The methods, techniques, processes, and logic described above can be embodied in a wide variety of ways and in a wide variety of combinations of hardware and software. For example, all or part of an embodiment may be circuitry including an instruction processor, such as a central processing unit (CPU), microcontroller, or microprocessor; an application-specific integrated circuit; a programmable logic device (PLD) or field-programmable gate array (FPGA); or circuitry including discrete logic or other circuit components, including analog circuit components, digital circuit components, or both, or any combination thereof. The circuitry may include discrete interconnected hardware components and / or may be combined on a single integrated circuit die, distributed among multiple integrated circuit dies, or may be embodied in a multiple chip module (MCM) of multiple integrated circuit dies within a common package, for example.

[0053] The circuitry may further include or have access to instructions executable by the circuitry. The instructions may be embodied as a signal and / or data stream and / or may be storable in a tangible storage medium other than a transient signal, such as flash memory, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or on a magnetic or optical disk, such as a compact disk read-only memory (CD-ROM), hard disk drive (HDD), or other magnetic or optical disk, or in or on another machine-readable medium. An article of manufacture, such as a computer program product, may include, among other things, a storage medium and instructions stored in or on the storage medium, which, when executed by circuitry in the device, enable the device to perform any of the processes described above or shown in the figures.

[0054] An implementation may be distributed as circuitry, e.g., hardware and / or a combination of hardware and software among multiple processors and memories, optionally including a polydistributed processing system, among multiple system components. Parameters, databases, and other data structures may be stored and managed separately, incorporated into a single memory or database, or may be locally and physically organized in a variety of ways, including embodied in a variety of ways, such as data structures like linked lists, hash tables, arrays, records, objects, or implicit storage. Programs may be a single program, portions of separate programs (e.g., subroutines), distributed across several memories and processors, or embodied in a variety of ways, such as libraries, shared libraries (e.g., dynamic link libraries (DLLs)). For example, a DLL may store instructions that, when executed by the circuitry, perform any of the processes described above or illustrated in the figures.

[0055] Various embodiments are described herein. Other embodiments are possible. Various embodiment terms are explicitly described below.

[0056] [Embodiment Item E1] In one embodiment, an apparatus includes an extrusion die with an extrusion output, the extrusion output being in the form of a slit to produce a film, the apparatus further includes a preform build platform and a translation stage, movement of the translation stage causes relative movement between the extrusion output and the preform build platform, and the apparatus further includes controller circuitry communicatively coupled to the translation stage, the controller circuitry sending movement commands to the translation stage to position the preform build platform so that a current film produced by the extrusion die is layered on top of a previous film produced by the extrusion die to create a preform stack.

[0057] [Embodiment Item E2] The apparatus of embodiment E1, wherein the extrusion die further has multiple extrusion inputs coupled to the extrusion output, optionally the extrusion die having up to 12 inputs.

[0058] [Embodiment Item E3] The apparatus of embodiment E1 or E2, wherein the extrusion die output is connected to the multiple extrusion inputs by channels that force material from the multiple extrusion inputs into a single stream for the extrusion output to produce a multi-layer film at the extrusion output.

[0059] [Embodiment Item E4] An apparatus as described in any one of embodiments E1 to E3, wherein each of the multiple subsets of extrusion inputs is coupled to a single material supply line to produce multiple sublayers of the same material within the film.

[0060] [Embodiment Item E5] The device of any one of embodiments E1-E4, wherein the subset includes extrusion input portions of odd-numbered membrane sublayers.

[0061] [Embodiment Item E6] An apparatus described in any one of embodiment items E1 to E5, wherein each of the complementary extrusion inputs is coupled to a separate single material supply line, the complementary sets including complements of the subsets, and optionally the complementary sets including extrusion inputs of even-numbered film underlayers.

[0062] [Embodiment Item E7] The apparatus of any one of embodiments E1 to E6 further comprises a roller fixed at a position relative to the extrusion output, the position being selected so that the roller exerts normal pressure on the membrane after it leaves the output.

[0063] [Embodiment Item E8] The apparatus of any one of embodiments E1-E7, further comprising a cutter fixed at a position relative to the extrusion output, the cutter communicatively coupled to the controller circuitry, and optionally the controller circuitry further configured to: determine when the translation stage has reached a layer end travel point for the preform stack; issue a cutting command to cause the cutter to apply a cutting action to the film when the translation stage is located at the layer end travel point; optionally define a layer start point for the translation stage; and optionally, after execution of the cutting command, issue a movement command to cause the translation stage to move to the layer start point.

[0064] [Embodiment Item E9] The apparatus of any one of embodiments E1 to E8, wherein the cutter includes an edge cutter, a laser cutter, and / or a heater.

[0065] [Embodiment item E10] The apparatus of any one of embodiments E1-E9, further comprising a dust shield disposed around the preform assembly platform and the extrusion output.

[0066] [Embodiment item E11] The apparatus of any one of embodiments E1-E10, further comprising an enclosure disposed around the preform assembly platform and the extrusion output, optionally the enclosure being dust-proof and / or moisture-resistant, optionally the enclosure housing a heater communicatively coupled to the controller circuitry, the controller circuitry configured to issue an enclosure command to cause the heater to maintain the enclosure temperature at a layer bonding temperature for the preform stack, and optionally the enclosure comprising a vacuum-sealed enclosure maintained at at least a low vacuum.

[0067] [Embodiment item E12] The apparatus of any one of embodiments E1 to E11, wherein the extrusion output has a thickness of 10 microns to 1,000 microns.

[0068] [Embodiment item E13] The apparatus of any one of embodiments E1 to E12, wherein the preform stack comprises an optical filter preform stack.

[0069] [Embodiment item E14] The apparatus of any one of embodiments E1-E13, wherein the extrusion die includes an extrusion die for a polymeric material, a glass material, or both.

[0070] [Embodiment paragraph E15] In one embodiment, an apparatus includes a sheet reservoir, a preform assembly platform, an assembly robot arm having a sheet gripper at a distal end thereof, a press having a heated press plate, a conveyor, and controller circuitry communicatively coupled to the robot arm, the conveyor, and the press, the controller circuitry being configured to: issue pick and place commands to the robot arm to select sheets from the sheet reservoir to build a vertical stack of sheets on the preform assembly platform; issue transport commands after the pick and place commands to the conveyor to translate the preform assemblies to the preform assembly platform leading to the press; and issue press commands after the transport commands to the press to apply heat and pressure to the vertical stack of sheets.

[0071] [Embodiment item E16] The apparatus of embodiment E15, wherein the sheet reservoir comprises a number of bins arranged in an array, each optionally containing a different type of sheet, a bin containing sheets stacked in stacking order, a conveyor belt onto which sheets are stacked in stacking order, a carousel containing a number of cartridges of sheets, a number of tracks each containing a different type of sheet, or any combination thereof.

[0072] [Embodiment item E17] The apparatus of embodiment E15 or E16, wherein the preform assembly platform includes a tray that holds a vertical stack of the sheets.

[0073] [Embodiment item E18] The device of any one of embodiments E15-E17, wherein the sheet grip comprises a clamp, a suction cup, or both.

[0074] [Embodiment paragraph E19] The apparatus of any one of embodiments E15 to E17, wherein the pick and place instructions include instructions for stacking the sheets in a repeating pattern.

[0075] [Embodiment item E20] The device of any one of embodiments E15 to E19, wherein the repeating pattern includes an alternating arrangement pattern of two types of sheets.

[0076] [Embodiment item E21] An apparatus as described in any one of embodiments E15 to E20, wherein the robot arm has a flat surface, and optionally the pick and place instructions include instructions to apply horizontal pressure using the flat surface to strengthen the stack of sheets.

[0077] [Embodiment item E22] An apparatus as described in any one of embodiment items E15 to E21, wherein the preform assembly platform has a sheet alignment sleeve, and optionally the sheet alignment sleeve is removable, and optionally the transport command, the pick and place command, or both commands include commands to remove the sheet alignment sleeve after the sheet stacking is completed.

[0078] [Embodiment item E23] The apparatus of any one of embodiments E15 to E22, wherein the press has a top press plate, a bottom press plate, a vacuum chamber, or any combination thereof, and optionally the press instructions include instructions to sandwich and press the vertical stack under vacuum, heat, or both.

[0079] [Embodiment item E24] The apparatus of any one of embodiments E15 to E23, wherein the press instructions include instructions for the heated press plate to heat to a layer bonding temperature for the vertical stack of sheets, and optionally, the layer bonding temperature is selected based on the composition of the materials in the vertical stack of sheets.

[0080] [Embodiment item E25] The apparatus of any one of embodiments E15-E24, wherein the conveyor comprises a conveyor belt, a robotic arm, or both.

[0081] [Embodiment item E26] An apparatus as described in any one of embodiments E15 to E25, further comprising a first roller arm, and optionally the controller circuitry is configured to send roller commands to cause the first roller arm to roll horizontally across the vertical stack of sheets after the sheets have been placed in accordance with the pick and place commands, and optionally the apparatus has a second roller arm, and optionally the roller commands further include commands to cause the second roller arm to roll parallel to the first roller arm on the opposite side of the vertical stack of sheets.

[0082] [Embodiment item E27] An apparatus as described in any one of embodiments E15 to E26, further comprising a cleaning station, and optionally the pick and place instructions include instructions for the robot arm to place the sheet in the cleaning station for cleaning prior to placing the sheet on the vertical stack, and optionally the cleaning station includes a dust pickup roll, an ionized air gun, or both.

[0083] [Embodiment item E28] In one embodiment, a method includes the steps of extruding a film through an extrusion die to an extrusion output, and translating a preform assembly platform relative to the extrusion output in coordination with the extrusion, wherein the film falls onto a preform stack on the preform assembly platform, the film forming a current layer of the preform stack on top of a previous layer of the preform stack, the previous layer also having been extruded through the extrusion die.

[0084] [Embodiment item E29] The method of embodiment E28 further includes the step of feeding the extrusion die through multiple extrusion inputs, optionally wherein the step of feeding the extrusion die includes feeding the extrusion die through up to 12 inputs.

[0085] [Embodiment item E30] The method of embodiment E28 or E29, wherein the step of feeding the extrusion die includes feeding the extrusion die through a channel that forces material from the multiple extrusion inputs into a single stream for the extrusion output to produce a multi-layer film at the extrusion output.

[0086] [Embodiment item E31] The method of embodiment E28, E29, or E30, wherein the step of feeding the extrusion die includes feeding the subset of multiple extrusion inputs from a single material feed line to produce multiple sublayers of the same material within the film.

[0087] [Embodiment item E32] The method of any one of embodiments E28 to E31, wherein the subset includes extrusion inputs of odd-numbered membrane sublayers.

[0088] [Embodiment item E33] A method according to any one of embodiment items E28 to E32, wherein the step of feeding the extrusion die includes feeding a complementary set of extrusion inputs from another single material supply line, the complementary sets including the complements of the subsets, and optionally the complementary sets including the extrusion inputs of even-numbered film underlayers.

[0089] [Embodiment item E34] The method of any one of embodiment paragraphs E28-E33, further comprising applying a roller on top of the current layer to apply normal pressure to the preform stack.

[0090] [Embodiment item E35] The method of any one of embodiment items E28 to E34, further comprising the step of cutting the current layer after covering the previous layer, and optionally the method further comprising the steps of confirming that the previous layer has been covered in response to the preform assembly platform reaching a layer end travel point, causing a cutter to perform the cutting when the translation stage is located at the layer end travel point, optionally determining a layer start point for the preform assembly platform, and optionally moving the preform assembly platform to the layer start point after the cutting.

[0091] [Embodiment item E36] The method of any one of embodiments E28 to E35, wherein the cutter includes an edge cutter, a laser cutter, and / or a heater.

[0092] [Embodiment item E37] The method of any one of embodiment paragraphs E28-E36, further comprising shielding the preform stack from dust while positioned on the preform assembly stack.

[0093] [Embodiment item E38] The method of any one of embodiments E28 to E37, further comprising the step of closing an enclosure around the preform stack during preform fabrication, optionally comprising a dust-proof and / or moisture-resistant enclosure, and optionally comprising a vacuum-sealed enclosure maintained at at least a low vacuum.

[0094] [Embodiment item E39] The method of any one of embodiment paragraphs E28-E38, further comprising heating the preform assembly platform to a layer bonding temperature.

[0095] [Embodiment item E40] The method of any one of embodiments E28 to E39, wherein said extruding said membrane comprises extruding a membrane having a thickness between 10 microns and 1,000 microns.

[0096] [Embodiment item E41] The method of any one of embodiments E28 to E40, wherein the preform stack comprises an optical filter preform stack.

[0097] [Embodiment item E42] The method of any one of embodiments E28-E41, wherein extruding the membrane includes extruding a polymeric material, a glass material, or both.

[0098] [Embodiment item E43] A method comprising using any of the above devices according to any one of embodiment paragraphs E1 to E27.

[0099] [Embodiment item E44] A manufacturing method that implements any of the apparatuses described in embodiments E1 to E27 and / or the methods described in embodiments E28 to E43 for producing a preform, optionally wherein the preform is an optical filter preform.

[0100] The headings and / or subheadings used herein or in the above-referenced US provisional patent application are intended solely to aid the reader in understanding the described embodiments.

Claims

1. 1. An apparatus comprising: an extrusion die having an extrusion output, the extrusion output being in the form of a slit to produce a membrane; a preform assembly platform; a translation stage, wherein movement of the translation stage causes relative movement between the extrusion output and the preform assembly platform; the apparatus having controller circuitry communicatively coupled to the translation stage, the controller circuitry sending motion commands to the translation stage to position the preform build platform so that a current film obtained by the extrusion die is layered on top of a previous film obtained by the extrusion die to create a preform stack.

2. the extrusion die further includes multiple extrusion inputs coupled to the extrusion outputs; 10. The apparatus of claim 1, wherein the extrusion die optionally has up to 12 inputs.

3. 3. The apparatus of claim 1, wherein the extrusion die output is coupled to the multiple extrusion inputs by channels that force material from the multiple extrusion inputs into a single stream for the extrusion output to produce a multi-sublayer film at the extrusion output.

4. 4. The apparatus of claim 1, wherein each of the multiple subsets of extrusion inputs is coupled to a single material supply line to produce multiple sub-layers of the same material within the membrane.

5. The apparatus of any one of claims 1 to 4, wherein the subset includes extrusion inputs of odd-numbered membrane sublayers.

6. each of the complementary extrusion inputs is coupled to a separate single material supply line, the complementary sets comprising the complements of the subsets; 6. Apparatus according to any one of claims 1 to 5, wherein optionally the complement comprises extrusion inputs of even-numbered membrane sublayers.

7. 7. The apparatus of claim 1, further comprising a roller fixed in a position relative to the extrusion output, the position being selected such that the roller exerts a normal pressure on the membrane after it leaves the output.

8. and a cutter fixed in position relative to the extrusion output, the cutter communicatively coupled to the controller circuitry, optionally the controller circuitry further comprising: determining that the translation stage has reached an end-of-layer travel point for the preform stack; When the translation stage is located at the layer end travel point, a cutting command is issued to cause the cutter to perform a cutting action on the film; Optionally, defining a layer starting point for the translation stage; and 8. Apparatus according to any one of claims 1 to 7, optionally configured to issue a movement command to move the translation stage to the layer start point after execution of the cutting command.

9. The apparatus according to any one of claims 1 to 8, wherein the cutter comprises an edge cutter, a laser cutter, and / or a heater.

10. The apparatus of any one of claims 1 to 9, further comprising a dust shield disposed around the preform assembly platform and the extrusion output.

11. an enclosure disposed around the preform assembly platform and the extrusion output; Optionally, the enclosure is dust-proof and / or moisture-resistant; Optionally, the enclosure houses a heater communicatively coupled to the controller circuitry, the controller circuitry configured to issue an enclosure command to cause the heater to maintain the enclosure temperature at a layer bonding temperature for the preform stack; Optionally, the enclosure comprises a vacuum-sealed enclosure held at least at a rough vacuum.

12. 12. The apparatus of any one of claims 1 to 11, wherein the extrusion output has a thickness of between 10 microns and 1,000 microns.

13. An apparatus according to any preceding claim, wherein the preform stack comprises an optical filter preform stack.

14. The apparatus of any one of claims 1 to 13, wherein the extrusion die comprises an extrusion die for a polymer material, a glass material, or both.

15. 1. An apparatus comprising: a seat reservoir; a preform assembly platform; an assembly robot arm having a seat grip at a distal end thereof; a press having a heated press plate; A conveyor and and controller circuitry communicatively coupled to the robotic arm, the conveyor, and the press, the controller circuitry comprising: issuing pick and place commands to the robotic arm to select sheets from the sheet reservoir and build a vertical stack of sheets on the preform assembly platform; After sending the pick and place command, issuing a transport command to the conveyor to translate the preform assembly to the preform assembly platform leading to the press; and an apparatus configured, after sending the conveying command, to send a press command to the press to apply heat and pressure to the vertical stack of sheets.

16. the sheet reservoir comprises a number of bins, each bin containing a different type of sheet, the bins optionally being arranged in an array; bins for holding sheets stacked in stacking order; a conveyor belt on which the stacked sheets are deposited in stacking order; A carousel containing multiple cartridges of sheets; Multiple tracks, each containing a different type of sheet, or 16. The device of claim 15, comprising any combination thereof.

17. 17. The apparatus of claim 15 or 16, wherein the preform build platform comprises a tray for holding a vertical stack of the sheets.

18. 18. The apparatus of any one of claims 15 to 17, wherein the sheet grip comprises a clamp, a suction cup, or both.

19. An apparatus according to any one of claims 15 to 17, wherein the pick and place instructions include instructions for stacking sheets in a repeating pattern.

20. 20. The apparatus of any one of claims 15 to 19, wherein the repeating pattern comprises an alternating pattern of two types of sheets.

21. the robot arm has a planar surface; 21. Apparatus according to any one of claims 15 to 20, wherein optionally the pick and place instructions include instructions for applying horizontal pressure using the flat surface to stiffen the stack of sheets.

22. the preform assembly platform has a seat alignment sleeve; Optionally, the seat alignment sleeve is removable; 22. The apparatus of claim 15, wherein optionally the transport command, the pick and place command, or both commands include a command to remove the sheet alignment sleeve after the sheet stacking is completed.

23. The press Top press plate, Bottom press plate, a vacuum chamber, or Any combination of these 23. Apparatus according to any one of claims 15 to 22, wherein optionally the pressing instructions include instructions to sandwich and press the vertical stack together under vacuum, heat, or both.

24. the press instructions include instructions to cause the heated press plate to heat up to a ply bonding temperature for the vertical stack of sheets; 24. Apparatus according to any one of claims 15 to 23, wherein optionally the layer bonding temperature is selected based on the composition of the materials in the vertical stack of sheets.

25. The apparatus of any one of claims 15 to 24, wherein the conveyor comprises a conveyor belt, a robotic arm, or both.

26. a first roller arm; Optionally, the controller circuitry is configured to send roller commands to cause the first roller arm to roll horizontally across the vertical stack of sheets after the sheets have been placed according to the pick and place commands; Optionally, the apparatus comprises a second roller arm; 26. Apparatus according to any one of claims 15 to 25, wherein optionally the roller instructions further comprise instructions for the second roller arm to roll parallel to the first roller arm on the opposite side of the vertical stack of sheets.

27. a cleaning station; Optionally, the pick and place instructions include instructions for the robotic arm to place the sheet in the cleaning station for cleaning prior to placing the sheet on the vertical stack; 27. Apparatus according to any one of claims 15 to 26, wherein the cleaning station optionally includes a dust pick-up roll, an ionised air gun, or both.

28. 1. A method comprising: extruding the film through an extrusion die to an extrusion output; and translating a preform assembly platform relative to the extrusion output in coordination with the extrusion, wherein the film falls onto a preform stack on the preform assembly platform, the film forming a current layer of the preform stack on top of a previous layer of the preform stack, the previous layer also being extruded through the extrusion die.

29. further comprising feeding the extrusion die through multiple extrusion inputs; 30. The method of claim 28, wherein optionally, the step of feeding the extrusion die includes feeding the extrusion die through up to 12 inputs.

30. 30. The method of claim 28 or 29, wherein the step of feeding the extrusion die includes feeding the extrusion die through a channel that forces material from the multiple extrusion inputs into a single stream for the extrusion output to produce a multi-sublayer film at the extrusion output.

31. 31. The method of claim 28, 29, or 30, wherein the step of feeding the extrusion die includes feeding the subset of multiple extrusion inputs from a single material feed line to produce multiple sub-layers of the same material within the film.

32. The method of any one of claims 28 to 31, wherein the subset comprises extrusion inputs of odd-numbered membrane underlayers.

33. the step of feeding the extrusion die includes feeding a complement of extrusion inputs from another single material supply line, the complement including a complement of the subset; 33. A method according to any one of claims 28 to 32, wherein optionally the complement comprises extrusion inputs of even-numbered membrane underlayers.

34. The method of any one of claims 28 to 33, further comprising applying a roller on top of the current layer to apply normal pressure to the preform stack.

35. further comprising the step of cutting the current layer after covering the previous layer; Optionally, the method further comprises: verifying that the previous layer has been coated in response to the preform assembly platform reaching a layer end run point; causing a cutter to perform the cutting when the translation stage is positioned at the layer end travel point; optionally defining a layer start point for said preform build platform; 35. The method of any one of claims 28 to 34, further comprising optionally, after said cutting, causing said preform assembly platform to move to said layer start point.

36. The method of any one of claims 28 to 35, wherein the cutter comprises an edge cutter, a laser cutter, and / or a heater.

37. The method of any one of claims 28 to 36, further comprising the step of shielding the preform stack from dust while it is positioned on the preform assembly stack.

38. further comprising the step of closing an enclosure disposed around the preform stack during preform fabrication; Optionally, the enclosure comprises a dust-proof and / or moisture-resistant enclosure; 38. A method according to any one of claims 28 to 37, optionally wherein the enclosure comprises a vacuum sealed enclosure held at least at a rough vacuum.

39. The method of any one of claims 28 to 38, further comprising heating the preform assembly platform to a layer bonding temperature.

40. 40. The method of any one of claims 28 to 39, wherein the step of extruding the film comprises extruding a film having a thickness between 10 microns and 1,000 microns.

41. The method of any one of claims 28 to 40, wherein the preform stack comprises an optical filter preform stack.

42. The method of any one of claims 28 to 41, wherein the step of extruding the film comprises extruding a polymer material, a glass material, or both.

43. A method comprising the step of using any of the devices according to any one of claims 1 to 27.

44. A manufacturing method implementing any of the apparatuses according to claims 1 to 27 and / or the methods according to claims 28 to 43 for making a preform, comprising: Optionally, the preform is an optical filter preform.

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