Transport path correlation techniques and related systems, methods, and devices

Abstract

To provide suitable transport path correlation techniques and related systems, methods, and devices.SOLUTION: A printer deposits material onto a substrate as part of a manufacturing process for an electronic product. At least one mechanical component experiences mechanical error, which is mitigated using transducers that equalize position of a transported thing, e.g., to provide an "ideal" conveyance path. A substrate conveyance system and / or a printhead conveyance system can each use transducers in this manner to improve precise droplet placement. In one embodiment, errors are measured in advance, with corrections being "played back" during production runs to mitigate reproducible transport path error. In a still more detailed embodiment, the transducers can be predicated on voice coils, which cooperate with a floatation table and floating, mechanical pivot assembly to provide frictionless, but mechanically-supported error correction.SELECTED DRAWING: Figure 6A

Description

[Technical field]

[0001]

[0001] This disclosure claims the benefit of U.S. Patent Application No. 15 / 642,037, filed on July 5, 2017 on behalf of first named inventor Digby Pun, U.S. Provisional Application No. 62 / 489,768, filed on April 25, 2017 on behalf of first named inventor Digby Pun, and U.S. Provisional Application No. 62 / 359,969, filed on July 8, 2016 on behalf of first named inventor Digby Pun, each entitled "Transport Path Correction Techniques And Related Systems, Methods And Devices," and U.S. Provisional Application No. 62 / 459,402, filed on February 15, 2017 on behalf of first named inventor David C. Darrow, entitled "Precision Position Alignment, Calibration and Measurement in Printing And Manufacturing Systems," each of which is incorporated herein by reference.This disclosure also relates to the following documents: U.S. Patent No. 9,352,561 (USSN 14 / 340403), filed as application on July 24, 2014 on behalf of first inventor Nahid Harjee for “Techniques for Print Ink Droplet Measurement And Control To Deposit Fluids Within Precise Tolerances,” U.S. Patent Publication No. 20150360462 (USSN 14 / 738785), filed as application on June 12, 2015 on behalf of first inventor Robert B. Lowrance for “Printing System Assemblies and Methods,” and U.S. Patent Publication No. 20150298153 (USSN 14 / 738785), filed as application on June 30, 2015 on behalf of first named Michael Baker for “Techniques for Arrayed Printing of a Permanent Layer with Improved Speed ​​and Accuracy.” No. 14 / 788609, and U.S. Patent No. 8,995,022, filed as application on August 12, 2014 on behalf of first named inventor Eliyahu Vronsky for “Ink-Based Layer Fabrication Using Halftoning To Control Thickness.” [Background technology]

[0002] One type of industrial printer can be applied to precision manufacturing, for example, the fabrication of electronic devices.

[0003] To take one non-limiting example, an inkjet printer can be used to deposit one or more ultra-thin layers of an electronic display device or a solar panel device. The "ink" in this case differs from the traditional concept of ink as a dye of a desired color, and can instead be organic monomers that diffuse and mix together somewhat but are not absorbed, deposited instead as discrete droplets that maintain an intentional layer thickness that serves to impart structural, electromagnetic, or optical properties to the finished device. Inks are also typically intentionally made to be translucent, and the resulting layer is used to generate and / or transmit light. Successive coats of ink deposited by printing are then processed in place (e.g., cured using ultraviolet light or otherwise baked or dried) to form a permanent layer with a very tightly tuned thickness, e.g., 1-10 microns, depending on the application. These types of processes can be used to deposit various conductors, such as hole injection layers ("HIL"), hole transport layers ("HTL"), hole transport layers ("HTL"), emissive or emissive layers ("EML"), electron transport layers ("ETL"), electron injection layers ("EIL"), anode or cathode layers, hole blocking layers, electron blocking layers, polarizers, barrier layers, primers, encapsulation layers, and other types of layers of an OLED pixel. The referenced materials, processes, and layers are merely exemplary. In one application, the ink can be deposited to create layers within each of many individual electronic components or structures within individual microscopic fluid reservoirs (e.g., within "wells") to form individual display pixels or solar cell layers, for example. In another application, the ink can be deposited to form one or more encapsulation layers that have macroscopic dimensions, for example, covering many such structures (e.g., spanning a display screen area with millions of pixels).

[0004] The required precision can be very fine; for example, a manufacturer's specifications for fabricating a thin layer of an organic light-emitting diode ("OLED") pixel may specify a condensed fluid deposition in a pixel well to picoliter resolution (or even to a higher level of precision). Even slight local variations in the volume of deposited fluid from the specifications can create problems. For example, variations in ink volume between structures (e.g., between pixels) can create hue or intensity differences or other performance differences that are noticeable to the human eye. In encapsulation or other "macroscopic" layers, such variations can impair layer function (e.g., a layer may not reliably seal electronic components sensitive to unwanted particulate matter, oxygen, or moisture) or create otherwise observable differences. As devices become smaller and smaller and the associated layers become thinner and thinner, these problems become even more significant. It will be appreciated that a typical application may feature a printer having tens of thousands of nozzles depositing discrete droplets, each having a volume of 1 to 30 picoliters ("pL"), and when it is considered that manufacturing process corners for printheads can lead to inoperable nozzles and individual errors in droplet size, nozzle location, droplet velocity, or droplet landing position, thereby causing localized ink volume delivery variations, there is an enormous challenge in producing thin, homogenous layers that closely follow the desired manufacturing specifications.

[0005] One source of error in achieving fine accuracy relates to the use of mechanical components in the fabrication process relative to the scale of the product being manufactured. As a non-limiting example, most printers have a mechanical transport system that moves one or more printheads, the substrate, or both to perform printing. Some printers may also feature transport systems for rotating or offsetting components (e.g., moving or rotating the printheads to change the effective pitch between the nozzles), each of which may impart fine mechanical or positioning errors and thus lead to non-uniformity. For example, even if these transport systems typically rely on high-precision components (e.g., precision tracks or edge guides), they may still impart jitter or translational or rotational inaccuracies (e.g., deviations on the scale of millimeters, microns, or smaller in the transport path) that make it difficult to achieve the required accuracy and uniformity throughout the transport path length used in production. To provide some context, equipment used to fabricate large HDTV screens may feature "room-sized" printers controlled to deposit ultra-thin layers of material onto meter-wide by meter-long substrates, where individual droplet deliveries are planned to nanometer-scale coordinates. Transport paths in such equipment may be meters in length. It is noted that there are many other mechanical components in such systems that may introduce some form of error, for example, transport path systems used to exchange printheads, camera assemblies that align or inspect the substrate, and other types of moving parts. In such systems, even mechanical parts with very fine precision may generate deviations that affect the nanometer-scale coordinates referenced above. Thus, the layers required become thinner and thinner, and the precision required becomes smaller and smaller relative to the product being fabricated, making it even more imperative to carefully control and / or mitigate potential sources of positional error.

[0006] Generally, there are several conventional techniques for reducing position and translation errors in these types of processing systems. First, the substrate can be roughly aligned with the printer transport and then finely aligned manually (potentially repeatedly during the processing process). Such a process is time-consuming, i.e., generally impeding the goal of having an automated high-speed assembly line type process for producing consumer products. It is also generally extremely difficult to obtain the required micron or nanometer accuracy using such manual processes. There are also some errors that cannot be adequately addressed using such techniques, such as errors caused by differences in the transport path as just introduced above (e.g., errors that appear after the substrate is aligned). As a second example, US Patent Publication No. 20150298153 relates to a process of measuring fine position and / or rotation errors in substrate position and correcting these errors in software, for example, by reallocating the nozzles used to print or by changing the nozzle drive waveforms used to fire the nozzles otherwise. In other words, generally speaking, these techniques attempt to "live with" minute position and rotation errors (thereby preserving printing speed) and then adjust the nozzles used, and when and how those nozzles are electronically controlled, to correct for the errors (e.g., using a pre-planned raster without having to readjust an error-dependent scan path). However, despite the usefulness of compensating for alignment errors in software, measuring and accounting for this error in software and recalculating firing allocations for thousands of nozzles can require significant computational resources and time.

[0007] What is needed are additional techniques for correcting motion, rotation, and position errors in mechanical systems in manufacturing equipment. Still further, what is needed are techniques for correcting errors in moving components of a manufacturing system to simulate an "ideal" edge or transport path. Such techniques, when applied to precision manufacturing processes, and in particular to printing systems of the type described, would reduce the need for significant computational resources and time to re-render raster control data, leading to an overall simpler and / or faster and / or more accurate printing process. The present invention addresses these needs and provides further related advantages. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a substrate 103 as it is transported through an industrial printing system along a transport path 107. To its right, FIG. 1 shows the substrate in two hypothetical positions (103′ and 103”) with respective rotational and translation errors (Δx, Δy, and Δθ). The transport path errors and associated substrate rotation and translation errors are considered to be exaggerated relative to the scale of the drawing to aid in illustration.

[0009] [Figure 2A] Figure 2A is a schematic diagram showing one or more transducers that perform fine mechanical adjustments and correct for the errors referenced in relation to Figure 1 (i.e., as part of the "gripper" that advances the substrate in this example). In one embodiment, repeatable mechanical errors are pre-measured and one or more transducers "T" are driven in response to the transport path position to correct for repeatable substrate rotation and translation errors relative to an ideal (e.g., "perfectly straight" or "jitter-free") transport path.

[0010] [Figure 2B]Figure 2B depicts a transport path 107 with mechanical imperfections similar to Figure 1. However, in this case, a transducer "T" as introduced relative to Figure 2A is used to perform fine adjustments of the substrate position and / or orientation as the gripper advances on the path 107. The result is that the substrate now moves according to an "ideal" motion (e.g., a perfectly straight "ideal" edge and / or a path containing no jitter), as represented by the imaginary straight edge 223.

[0011] [Figure 2C] Figure 2C is similar to Figure 2B in that it illustrates the use of a transducer "T" to correct for transport path errors. However, in this case errors also potentially arise from a second transport path 256, which in this case exhibits non-ideal motion of the print head (or camera or other assembly) as it progresses in the general direction of arrow 254.

[0012] [Figure 2D] FIG. 2D is similar to FIG. 2C in that it depicts the motion of the print head along an edge or track 256, but as shown, the print head assembly now also has its own transducer assembly, providing fine position and rotation corrections that mitigate errors in the edge or track 256, with the result that the print head now also effectively travels a hypothetical "ideal" path 225 (or 269, as will be discussed below).

[0013] [Figure 2E]FIG. 2E depicts an alternative embodiment in which errors in one transport path (e.g., print head transport path) can be mitigated by error correction mechanisms in a different transport path. For example, an error correction mechanism such as a transducer "T" associated with gripper 203 can implement fine adjustments to the substrate position or orientation that compensate for errors in a different transport path (e.g., print head transport path, etc.). Note that the corrections can depend on multiple variables, e.g., they can be made depending on time-dependent motion or position along other transport paths. For example, transducer "T" can be controlled as gripper 203 moves in the "y" dimension in a manner that also depends on the print head assembly position along track 256, such that the substrate follows virtual path 107'" or virtual path 107"" (i.e., depending on both gripper position and print head assembly position).

[0014] [Figure 3A] FIG. 3A is a flow chart associated with correcting position and / or rotational errors as a transported object is advanced along a transport path.

[0015] [Figure 3B] FIG. 3B is an illustrative diagram showing a mechanism for correcting transport path errors, for example, by implementing compensatory counter-motions (or other error mitigation) in up to six different dimensions (e.g., potentially including three translational dimensions, plus yaw, pitch, and / or roll).

[0016] [Figure 4A] 4A provides a plan view of a substrate and illustrates the raster or scanning process. The shaded areas 407 represent a single scan path, while the transparent areas 408 represent alternative paths. As indicated by the dimensional legend in the figure, in this example, the "x" axis corresponds to the cross-scan dimension, while the "y" axis corresponds to the in-scan dimension.

[0017] [Figure 4B]FIG. 4B provides a top schematic view of a processing machine that includes multiple modules, one of which (415) features a printer within a controlled atmosphere.

[0018] [Figure 4C] FIG. 4C is a block diagram illustrating one method 431 for measuring, recording, and then correcting repeatable transport path errors in an industrial printing system.

[0019] [Figure 4D] 4D illustrates how one or more printheads are aligned with the gripper during an initialization process, thereby establishing the coordinate reference system used by the printer (e.g., the coordinate system used by the printer support table). During production, as each new substrate in a series is introduced into the printer, it is also then aligned to this same reference system as part of printing. Aligning each of the printheads and each substrate to a common reference system allows the printheads and substrates to always be properly aligned with one another during printing.

[0020] [Diagram 5] FIG. 5 is an illustrative diagram showing a series of optional layers, products, or services that can each independently embody the techniques introduced herein; for example, these techniques can be implemented in the form of software (by numeral 503), or as printer control data (by numeral 507) used to control a printer to print on a substrate or otherwise correct reproducible errors, or as products made relying on these techniques (e.g., as illustrated by numerals 511, 513, 515, or 517).

[0021] [Figure 6A] FIG. 6A is a detailed perspective view of one embodiment of an industrial printer, such as the printer inside the print module of FIG. 4B.

[0022] [Figure 6B]FIG. 6B is a detailed perspective view of an embodiment of a gripper.

[0023] [Figure 6C] FIG. 6C is a close-up perspective view of the transducer assembly from the gripper of FIG. 6B.

[0024] [Figure 6D] FIG. 6D is a close-up perspective view of the floating mechanical pivot assembly from the gripper of FIG. 6B.

[0025] [Figure 6E] FIG. 6E is a schematic perspective view of the error correction system represented by FIGS. 6B-6D, with emphasis on the design of the floating mechanical pivot assembly.

[0026] [Figure 7A] 7A is a perspective view of a substrate (e.g., for a gripper) and transport system used to measure errors. A laser interferometry system directs light through optics 707 mounted on the displaceable or "second component 705" of the gripper or what is being transported (e.g., substrate 705) and interferometric techniques are used to measure very small (e.g., micron / millaridian scale or smaller) position or angular deviations (including vibrations).

[0027] [Figure 7B] FIG. 7B provides a side view of the printhead (or camera) traveler assembly, i.e., the camera or printhead assembly 745, along with optics 743 mounted on the camera or printhead assembly, moves back and forth along a traveler 747 to measure very slight position or angular deviations that affect the movement and orientation of the assembly 745.

[0028] The subject matter defined by the recited claims may be better understood by reference to the following detailed description, which should be read in conjunction with the accompanying drawings. This description of one or more specific embodiments, which are designed below to enable one to build and use various implementations of the techniques described by the claims, is not intended to limit the recited claims, but to illustrate their applications. Without limiting the foregoing, the present disclosure provides several different examples of techniques for mitigating transport path errors in a manufacturing apparatus or printer, and / or for processing thin films for one or more products of a substrate as part of a reproducible printing process. The various techniques can be embodied in various forms, for example, in the form of a printer or manufacturing apparatus or components thereof, in the form of control data (e.g., pre-calculated correction data or converter control data), or in the form of an electronic or other device that is processed as a result of these techniques (e.g., having one or more layers produced according to the described techniques). Although specific examples are presented, the principles described herein may also be applied to other methods, devices, and systems. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The present disclosure provides improved techniques for correcting transport path errors and / or for processing layers on a substrate with a high degree of positional accuracy. In one embodiment, these techniques are applied to a manufacturing apparatus or system that produces a layer of an electronic display, a solar panel, or another electronic device or product.

[0030] More specifically, in the specific embodiments discussed herein, the printer deposits droplets of liquid on the substrate, which droplets mix to form a continuous coat of liquid, and the liquid will serve as a source of material and be used to form the desired layer. The liquid can be, for example, a monomer that is then cured in situ to form a polymer, or can carry a material that will form the desired layer as the liquid dries or bakes. During deposition of the droplets, the substrate or another component of the printer, such as a camera or print head, is advanced along a transport path. The transport path or conveyance system is characterized by very slight mechanical imperfections that generate at least one of translational or rotational errors that affect the deposition of the material and / or individual droplets on the substrate. These errors can be repeatable, e.g., in an assembly line type process, imperfections in the transport path can affect every new substrate in a predictable manner.

[0031] To correct and / or mitigate the errors, in one embodiment, fine positioning transducers are driven without a fixed pivot point to counter mechanical imperfections. These transducers perform fine adjustments of the substrate position and / or orientation, thereby countering the effects of mechanical imperfections in at least one dimension. In this way, the transport system (e.g., gripper, substrate, print head, camera, or other transport path) continues to be characterized by mechanical imperfections, but the motion of the substrate and / or print head is performed to approximate an ideal progression. In one embodiment, the transport path is linear and transport occurs along a first dimension (e.g., the "y" dimension), while two or more transducers each independently apply a linear offset in an independent dimension (e.g., the "x" dimension). When driven in common mode, these transducers allow for the offset of imperfections associated with the transport system that affect the "x" dimension position of the substrate. For example, the transported object can be made to progress a virtual straight edge in the "y" dimension. When driven in differential mode, the transported entity can also be rotated in the "xy" plane to correct for orientation errors similarly caused by mechanical imperfections in the transport path.

[0032] For example, in a split-axis system used to fabricate electronic devices on a substrate, a "gripper" can be used to move the substrate along a first dimension (e.g., the "y" dimension). The gripper has a first component that rides along an edge or track and a second component (typically a vacuum device) that engages and locks onto the substrate. A transducer can be operatively positioned between the first and second components to provide selective offsets between the first and second components at two or more discrete points of interaction, providing both common mode and differential mode displacements as referenced above. When the first component experiences translational and rotational deflections caused by mechanical imperfections in the transport system (e.g., in the second dimension), the transducer is driven to precisely equalize these deflections in that dimension, essentially providing the second component with a "virtual edge" or "virtual transport path" that is not characterized by mechanical errors. Note that the errors can be linear and nonlinear, and the corrections can be correspondingly linear and nonlinear. In optional embodiments, this type of system can be embodied in a printer or printing system, where, for example, the y dimension is one of the substrate transport dimension and / or the "in-scan" or "cross-scan" dimension, and the x dimension is the other of the print head transport dimension and / or the "in-scan" or "cross-scan" dimension. Note that the described techniques are not limited to print head / substrate transport even in such systems, but can also be applied, for example, but not limited to, to correct for the motion of cameras, measurement devices, or other components. Note also that the various described dimensions, axes, and associated reference frames are arbitrary and can be inverted or exchanged for other reference frames or other degrees of freedom.

[0033] In one embodiment, mechanical defects can be measured in advance, and corrections can then be stored, calculated, "reproduced," and / or "read" during each new deposition (e.g., for each subsequent substrate in the series) to counter reproducible mechanical errors in at least one dimension. These corrections can be indexed according to any desired variables, such as transport path position, temperature, specific printing recipe, and / or other variables. In such an embodiment, mechanical defects can be optionally remeasured occasionally or periodically to account for changing conditions (e.g., mechanical part degradation). For example, in an assembly line type fabrication process, such techniques can be applied to "reproduce" stored error corrections depending on the position (e.g., of the first component) of the transport system, to counter reproducible or predictable motion or position errors.

[0034] There may be multiple transport paths in a manufacturing system, and these techniques may be applied to any one or combination of these transport paths, and may be applied to correct for positional errors (or rotational errors) in one dimension or errors in multiple dimensions. A few examples will help highlight this point.

[0035] First, in one contemplated implementation, these techniques are used to correct cross-scan dimension errors in substrate position as a function of gripper position along the transport path. The gripper has a first and second component as referenced above and a linear transducer operatively coupling these components at at least two interaction points, the transducer structured to provide a "floating" pivot point. As the first component progresses along the transport path, the transducer is controlled to provide a "common mode" and a "differential mode" offset that repeatedly provides translation offsets in the cross-scan dimension and rotational adjustments of the substrate. The substrate is thus advanced in a linear path despite mechanical imperfections in the transport system. Various embodiments of the described transducers will be provided below, but briefly, in one embodiment, a "voice coil" can be used for these transducers to provide very precise microscopic throws. A floating mechanical pivot assembly compatible with common and differential drive modes can also be optionally used to help provide structural support and interconnection between the first and second components.

[0036] Second, in an optional extension to this first example, the gripper position (and / or the position of a second component of the gripper) can also be corrected in the in-scan dimension. For example, in one embodiment, the electronic drive signals (used to advance the gripper or otherwise trigger printer nozzle firings) are adjusted to correct for substrate position errors in the in-scan dimension. It is also possible to use another transducer (e.g., another voice coil or other transducer) to offset the first component relative to the second component in the in-scan dimension. In the first technique, the in-scan position errors are measured and used to offset individual nozzle firings (i.e., precisely corrected intentionally). In a second technique, a common or shared nozzle trigger signal can be generated as a function of the gripper position (and / or the position of the first component of the gripper) and can be corrected for errors such that the trigger signal is generated to simulate error-free movement of the gripper.

[0037] In yet another contemplated implementation, the basic technique can be applied to correct errors in yet other ways. For example, a printhead assembly traveling in the cross-scan dimension has a first component that follows a path or edge and a second component that carries one or more printheads. Transducers are used to couple the first component to the second component at at least two interaction points, as referenced above with respect to the gripper, and the transducers are similarly structured to provide a "floating" pivot point. As the first component travels the transport path, the transducers are controlled to provide "common mode" and "differential mode" offsets that repeatedly provide translational and rotational adjustments to the in-scan dimension. Errors in printhead position are thus mitigated, and such droplets are precisely ejected at the correct location relative to the printer's frame of reference. Again, various embodiments of the described transducers will be provided below, but briefly, in one embodiment, these transducers can also be voice coils that provide a microscopic throw.

[0038] In an optional extension, the first and second components and converters in this second embodiment can be structured to provide cross-scan dimension correction instead, or both in-scan and cross-scan dimension correction. As already suggested, the converters in the first embodiment referenced above can also be structured to provide in-scan dimension correction (i.e., of the substrate position), or both in-scan and cross-scan dimension correction instead. These various techniques can be mixed and matched in any desired combination or permutation. Also, as already suggested, in one possible application, a converter associated with one transport system (e.g., a gripper) can be used to correct errors in another transport system (e.g., depending on the printhead position along the independent transport path). As will be discussed further below, such techniques can also be applied to correct for differences in coordinate system non-orthogonality.

[0039] Considering the principles discussed thus far, at least one transducer can be used to correct for transport path errors by displacing what is being transported in a dimension orthogonal to the direction of transport using both common mode and differential mode control. In still further detailed embodiments, this type of control can be applied to the "y" axis motion of a first transport system and to the "x" axis motion of a second transport system, for example, to correct for transport path errors in two different transport paths using separate sets of transducers. In this manner, correcting two different transport paths, and in one implementation, forcing each transported object to follow a virtual linear edge, facilitates precise correction across deposition and / or processing parameters. For example, in the context of the split-axis printing system introduced above, correction of both the gripper / substrate path and the printhead path effectively normalizes the printing grid, providing a system in which the system's understanding of the printing grid coordinates is precisely correct and not undermined by errors in the mechanical system associated with the transport. These techniques and their various combinations and permutations, optionally with others of the techniques described herein and / or in the various documents incorporated by reference, serve to provide precise positional control for the deposited droplets. For example, these techniques can be further applied to "z-axis" (e.g., elevation) or other dimensional motion control. Alternatively, the techniques described herein can be combined with the use of droplet and / or nozzle parameters per nozzle, as described, for example, in U.S. Pat. No. 9,352,561 and U.S. Publication No. 20150298153.

[0040] This disclosure will be broadly organized as follows: (1) Figures 1-2F will be used to provide an introduction regarding depositing material on a substrate, causes of micro alignment errors, and associated remedies; (2) Figures 3A-4D will be used to introduce more specific techniques, i.e., regarding online and offline processes for measuring / detecting and combating errors in the considered printing environment; (3) Figures 5-6E will be used to explain specific mechanical structures in one or more detailed embodiments; (4) Figures 7A-B will be used to discuss systems used to measure and / or pre-record transport path measurement errors.

[0041] Before proceeding with the introduction, it may be useful to first introduce certain terminology that will be used herein.

[0042] A specifically contemplated implementation may include an apparatus comprising instructions stored on a non-transitory machine-readable medium. Such instruction logic may be written or designed in a manner having a certain structure (architectural features) to cause one or more general-purpose machines (e.g., processors, computers, or other machines) to behave as special-purpose machines, each having a structure that necessarily performs a task described on input operands depending on the instructions, which when ultimately executed, take a specific action or otherwise produce a specific output. As used herein, a "non-transitory" machine-readable or processor-accessible "medium" or "storage device" refers to any tangible (i.e., physical) storage medium from which instructions may subsequently be read by a machine, including, for example, but not limited to, random access memory, hard disk memory, optical memory, floppy disks, CDs, solid-state drives (SSDs), server storage devices, volatile memory, non-volatile memory, and other tangible mechanisms, regardless of the technology used to store data on the medium. The medium or storage device can be in a stand-alone form (e.g., a program disk or solid-state device) or can be embodied as part of a larger organization, such as a laptop computer, a handheld device, a server, a network, a printer, or other set of one or more devices. The instructions can be implemented in different forms, such as as metadata that is effective to invoke an action when invoked, as Java code or script, as code written in a specific programming language (e.g., as C++ code), as a processor-specific instruction set, or in some other form. The instructions can also be executed by the same processor or different processors or processor cores, depending on the embodiment. Throughout this disclosure, various processes will be described, any of which may be implemented as instructions stored on a generally non-transitory machine-readable medium, any of which may be used to fabricate a product.Depending on the product design, such products may be processed to be in a sealable form or as a preliminary step for other printing, curing, manufacturing, or other processing steps that will ultimately create a finished product for sale, distribution, export, or import, in which these products incorporate the engineered layers. Also, depending on the implementation, the instructions may be executed by a single computer, or in other cases may be stored and / or executed on a distributed basis, for example, using one or more servers, web clients, or application specific devices. Each of the functions described with reference to the various figures herein may be part of a composite program or as stand-alone modules, both stored on either a single media representation (e.g., a single floppy disk) or on multiple separate storage devices. The same applies to the error correction information generated according to the process described herein, i.e., templates representing position errors as a function of transport path position, can be stored on a non-transitory machine-readable medium for temporary or permanent use, either on the same machine or for use on one or more other machines. For example, such data can be generated using a first machine and then stored for transfer to a printer or manufacturing device, e.g., for downloading via the Internet (or another network), or for manual transport (e.g., via a transport medium such as a DVD or SSD) for use on another machine. A "raster" or "scan path" as used herein refers to the progression of the print head or camera motion relative to the substrate, i.e., this need not be linear or continuous in all embodiments. The terms "hardening," "solidifying," "treating," and / or "rendering" of a layer refer to a process applied to deposited ink to transform it from a fluid form into a permanent structure of what is being made. These terms are relative terms, e.g., the term "hardened" does not necessarily require that the finished layer be objectively "hard", so long as the finished form is "harder" than the liquid ink deposited by the printer. The term "permanent", as in "permanent layer", refers to something that is intended for indefinite use (e.g., as opposed to a manufacturing mask layer that is typically removed as part of the manufacturing process). Throughout this disclosure, various processes are described, any of which may be implemented as instruction logic (e.g., as instructions stored on a non-transitory machine-readable medium or other software logic), as hardware logic, or as a combination of these, depending on the embodiment or specific design. A "module" as used herein refers to a structure dedicated to a specific function, e.g., a "first module" that performs a first specific function and a "second module" that performs a second specific function refer to mutually exclusive sets of code when used in the context of instructions (e.g., computer code).When used in the context of a mechanical or electromechanical structure (e.g., an "encryption module"), the term "module" refers to a dedicated set of components, which may include hardware and / or software. In all cases, the term "module" is used to refer to a specific structure for performing a function or operation that would be understood by one of ordinary skill in the art to which the subject matter pertains, as a conventional structure used in the specific technical field (e.g., a software module or a hardware module), rather than as a general placeholder or "means" or "any structure whatsoever" to perform a described function (e.g., a "team of bulls"). "Electronic", when used to refer to a method of communication, can also include audible, optical, or other communication functions, e.g., in one embodiment, electronic transmission can encompass optical transmission of information (e.g., via an imaged 2D barcode) that is digitized by a camera or sensor array, converted to an electronic digital signal, and then exchanged electronically.

[0043] Also referred to herein are detection mechanisms and alignment marks or fiducials recognized on each substrate, or as part of the printer platen or transport path, or as part of the printhead. In many embodiments, the detection mechanism is an optical detection mechanism that uses a sensor array (e.g., a camera) to detect a recognizable shape or pattern on the substrate (and / or on a physical structure within the printer). Other embodiments do not assume a sensor array, for example, a line sensor can be used to sense the fiducials as the substrate is loaded into or advanced through the printer. Note that while some embodiments rely on dedicated patterns (e.g., special alignment marks), others rely on recognizable optical features (including the geometry of any pre-deposited layers on the substrate or physical features in the printer or printhead), each of which is a "fiducial." In addition to using visible light, other embodiments rely on ultraviolet or other non-visible light, magnetic, radio frequency, or other forms of detection of substrate details relative to the expected print location. It should also be noted that while various embodiments herein will be discussed with reference to a printhead, multiple printheads, or printhead assemblies, it should be understood that the printing systems described herein may generally be used with one or more printheads. In one contemplated application, for example, an industrial printer features three printhead assemblies, each assembly having three separate printheads with a mechanical mounting system that allows positional and / or rotational adjustments such that the constituent printheads and / or printhead assemblies (e.g., of the printhead assemblies) can be individually precisely aligned to a desired grid system. Various other terms will be defined below or used in a manner clear from the context.

[0044] I. Introduction 1 and 2A-2F are used to introduce some of the techniques discussed in this disclosure and some of the problems that these techniques address.

[0045] More specifically, FIG. 1 depicts a prior art process 101 associated with a certain type of transport mechanism. In this specific example, it is assumed that there is a substrate 103 that is to be printed with droplets deposited at selected nodes of a printing grid 105. The printing grid 105 is illustrated as being centered within the substrate to represent where it is intended that droplets of ink from the printhead will land at precise locations with a predictability that translates to layer uniformity. However, it should be noted that while illustrated in this manner, the printing grid is defined relative to the printer (but not necessarily the substrate) and extends to anywhere where printing may occur (e.g., the printable area may be larger than the substrate). Also, the spacing of the vertical and horizontal lines is generally believed to be predictably spaced, however, this is typically based on the assumption that advancement along the x and y transport paths is precise (and / or linear). Finally, and while a printer, substrate, and printed grid are illustrated herein, it should be noted that these problems are not specific to printers, and the techniques described herein may be applied to a wide variety of situations in which something is mechanically transported, rotated, or moved. The context of printing processes, substrates, and printed grids is used as a non-limiting illustrative example to introduce the problems and techniques described in this disclosure.

[0046] Printing occurs as the substrate is transported, generally as represented by arrow 104, and a transport mechanism is assumed to guide the substrate along a path 107. This transport path is illustrated in FIG. 1 as being slightly curved, which in this example represents mechanical imperfections in the transport mechanism (e.g., some type of edge guide, track or traveler, or other conveying system used to steer the substrate 103). Note that in a typical industrial printing process, such as for making OLED display panels as described above, the substrate may be approximately 2 meters by 3 meters in size, while the nonlinearity of the path 107 may be a few microns or even smaller. The curvature (or other errors) of the path 107 as depicted in FIG. 1 is therefore exaggerated for purposes of discussion and illustration. While errors of this magnitude are not significant in many applications, in some manufacturing processes (e.g., the manufacture of OLED displays and / or some other electronic devices on large substrates), errors of this type may limit the achievable product size, lifetime, or quality. That is, the droplets generally need to be deposited at precise locations so that they mix together and produce a homogenous layer without leaving gaps or pinholes. Upon landing, the droplets spread only to a limited extent, and surface irregularities in the finished layer can limit the achievable layer thinness and otherwise create quality issues. Even slight mislocation of the droplet landing site can affect product quality and / or manufacturing reliability.

[0047] FIG. 1 as a diagram is conceptually divided into two halves, including a left half and a right half. The left half of the diagram shows a substrate 103 and a slightly curved transport path 107. The substrate 103 is generally advanced back and forth along this path 107 in what is designated the "y" dimension, as referenced by arrow 104. The numeral 103 represents that the substrate is at some point in proper alignment with a printing grid 105. The printing grid as depicted in this diagram is an abstraction in which the vertical lines represent the apparent paths of the individual nozzles of the printhead as the printhead and substrate are moved relative to one another, while the horizontal lines represent digital firing signals or other capabilities of the nozzles to refill and fire repeated drops of ink (i.e., the spacing of these horizontal lines typically represents the "speed" at which the nozzles can fire). Alternatively, described differently, the printing grid 105 has nodes, each of which represents an opportunity to fire a drop of ink. As already indicated, it is desirable to deposit the ink in a manner that is precisely controlled in terms of position and leaves no pinholes, which is achieved in part by having precise knowledge of where each droplet will land on the substrate. It is further noted that the droplets are deposited at discrete locations, but are viscous and therefore typically spread out to form a continuous liquid coat that has no gaps or irregularities. The volume per unit area is generally pre-correlated with the desired thickness or other properties of the final layer, and thus the droplet density and relative position can in theory be selected (taking into account the expected droplet size) in a manner that promotes a uniform layer of the desired thickness after droplet spreading and mixing to produce the desired effect (this is discussed in U.S. Pat. No. 8,995,022, which is incorporated by reference).

[0048] The printing grid 105 is depicted diagrammatically in the left half of the figure in a "squared up" fashion with the substrate 103, representing where printing will generally occur at the desired drop landing locations.

[0049] Unfortunately, errors (i.e. curvature) in the transport path 107 can effectively distort the printing grid 105, meaning that droplets do not always land where they are supposed to be relative to the substrate, as they are subject to minute positional and rotational errors as the substrate is advanced. The right hand side of FIG. 1 illustrates the translation and / or orientation errors of the substrate as it is advanced from a first position d0 along the transport path 107, with the substrate position and yaw represented by 103′ relative to a (virtual) ideal “reference edge” 109, to a second position d1 along the transport path, with the substrate position and yaw represented by 103″ relative to the reference edge 109. As can be seen, the substrate is subject to offset and rotational errors in multiple dimensions due to errors (e.g. curvature) of the transport path 107. The errors can be seen in this example to be horizontal and vertical offsets Δx0 and Δy0, and angular offset Δθ0 when the substrate is moved to the first position d0, and different horizontal and vertical offsets Δx1 and Δy1, and angular offset Δθ1 when the substrate is advanced to the second transport path position d1. As the nature of these errors changes as the substrate is advanced, these errors , distorts the printing grid, meaning that the planned printing process (in theory) produces the desired layer properties, but in practice the droplet deposition may be distorted, resulting in potential quality issues. If left uncorrected, these various errors may produce pinholes, thin zones, and other defects, which limit the precision and / or quality achievable with the printing system. Again, this may limit device size (e.g., it may be difficult or impossible to produce products with better quality or resolution, such as high quality miniaturized products or very thin large area display screens). The effect of the described type of error is to distort the printing grid. For example, the system and printing plan may effectively assume a straight printing grid (105 in FIG. 1), while "y" errors and / or jitter (i.e., parallel to the transport path) effectively distort the separation between the horizontal lines of that printing grid.Similarly, "x" dimension errors and / or jitter will effectively distort the separation between the vertical lines of that printing grid, and the effect of these errors is an error in the system's understanding of where individual drops are to be deposited. These types of errors can result in too little or too much fluid deposition in various pixel wells, or other non-uniformities, potentially leading to brightness and / or hue variations or other errors in the finished display.

[0050] Also, in this example, it should be noted that the errors depicted may, in some cases, simply be a repeatable function of the transport path 107, i.e., there is a nonlinear displacement in the x dimension, a nonlinear displacement in the y dimension, and a nonlinear tilt, since the transport path is considered as curved in this example. Other types of errors, such as z-dimension errors, pitch, and roll, may also potentially occur on a repeatable basis, but are not depicted in this particular figure. Thus, in applications such as industrial printers used to create fine (e.g., micron or smaller scale) electronic, optical, or other structures that rely on uniformity of the type described, the same errors may potentially occur from substrate to substrate if a series of substrates are to be printed as part of an "assembly line" type fabrication process.

[0051] Although errors in the substrate path are illustrated, there are other sources of similar errors that can potentially affect device quality and / or process reliability. For example, split-axis printers typically move not only the substrate, but also printheads or cameras, or other mechanical components. Briefly, in systems that move one or more printheads (generally in the "x" dimension relative to FIG. 1), similar path errors can result in "x", "y" rotations or other errors in the printheads (relative to the dimensions of FIG. 1). For example, if the printheads have errors in different positions, such also typically have the effect of distorting the vertical lines of the printing grid 105 (i.e., spacing them unevenly). Similar similarities can be drawn with respect to other transport path similarities in industrial printing systems of the referenced type. In general, it is desirable to reduce the effects of these layers and improve predictability and reliability in layer processing, and generally have the ability to process thinner, more homogenous layers.

[0052] FIG. 2A shows one embodiment 201 to reduce or eliminate some of these problems. More specifically, FIG. 2A shows the substrate 103 from FIG. 1 where it is again assumed that the substrate is advanced back and forth along a path represented by arrow 104. In this example, the substrate will be advanced using a gripper 203 that grips a corner or edge of the substrate 103. A first component 204 of the gripper will generally travel along a path 107 (from FIG. 1) in the "y" dimension. The gripper also has two transducers (T) 205 and 206 that operably connect the first component 204 with a second component 207 that engages the edge of the substrate. In one exemplary case, the substrate is supported on air bearings above a floating table and the corners of the substrate are gripped using a vacuum mechanism to provide a nearly frictionless support, in other examples other mechanisms can be used for support and transport. Each of the two transducers is controlled to displace the second component relative to the first component along a common direction (e.g., in the "x" dimension as illustrated in the figure), as represented by arrow 210. Each transducer can be controlled independently, leading to a situation where "common mode" control linearly offsets the second component away from the first component 204 in the x dimension at a respective engagement point, while "differential mode" control pivots the second component relative to the first component about a pivot point "Xpvt". It can be seen that the pivot point "Xpvt" is a floating pivot point because the transducers can be electronically driven in a manner that has both common and differential drive components. In some embodiments, this floating pivot point can be an abstract concept, while in other embodiments, a mechanical structure provides this pivot point while also providing a structural coupling between the two components of the gripper. The first component 204 follows the error-obstructed path 107 from FIG. 1 , while the second component locks onto what is being transported (e.g., in this case, substrate 103, e.g., using a vacuum lock).It can be seen that transducers 205 and 206 are independently controllable to move the substrate, as indicated by arrows 208 and 209, in a manner to precisely nullify x-dimension and θ-rotation-induced errors within path 107, with the result that the substrate is moved in a manner that corresponds to an ideal “reference edge” (see line 109 from FIG. 1). Note that in an alternative design, instead of having linear throws that are parallel to one another, transducer 205 may effect rotation while transducer 206 may effect a linear throw, or the transducers may be made to generate an offset in the “y” dimension or any other desired dimension, with the corresponding effect of mitigating substrate position or rotation errors. In FIG. 2A, the first component 204 of the gripper moves along the “y” dimension, while transducers 205 and 206 each push and pull the substrate along a linear range of motion along the “x” dimension via contact at respective contact points “c”. Note that each transducer, in this example, can be a linear motor, a piezoelectric transducer, a voice coil, or another type of transducer.

[0053] It should be noted that in the split-axis printing system in this example, the substrate is advanced in the "y" dimension relative to the printhead for a particular "scan" or raster movement. The "y" dimension in this example therefore also forms the "in-scan" dimension. The printhead is then moved in the "x" dimension (i.e., in the "cross-scan" dimension) to reposition the printhead for the subsequent scan, and the substrate is then advanced in the opposite direction for the subsequent scan, with successive scans continuing until the entire liquid coat has been created. The substrate can then be advanced (typically out of the printer to another chamber) which is cured, dried, or otherwise processed to convert the successive liquid coats into permanent structures having the desired electrical, optical, and / or mechanical properties. The printing system is then ready to receive another substrate and perform similar printing on the subsequent substrates, for example according to a general pre-defined "recipe".

[0054] It has already been described that errors along the transport path 107 (from FIG. 1) can lead to errors in multiple dimensions (i.e. not only offsets in the x dimension). For example, the motion along the path 107 can be controlled for a constant velocity, but variations in the angle of that path can also lead to nonlinearities in the y position of the substrate. With respect to the embodiment of FIG. 2A, the y dimension errors can be optionally corrected using a means 211 for correcting the substrate motion in the "in-scan" dimension, for example using a third transducer 214 that achieves a throw of the first and / or second components of the gripper in the in-scan dimension and normalizes the y dimension advancement of the substrate. In other embodiments, feedback can instead be used to adjust the electronic control signal 215 (for example as a feedback signal, delta signal, or electronic drive signal) for the advancement of the gripper, imparting a slight velocity increase or decrease (Δv) to counter the y dimension errors, or the motion of the gripper can be triggered to match the position markers (see further below). In yet another optional embodiment, individual y-position dependent nozzle firing delays (as represented by box 217) can also be calculated and programmed, i.e., the nozzles of the print head can be "commanded" to print slightly earlier or later as the substrate and print head are moved relative to one another in the "y" dimension in a manner that, in some embodiments, exactly accounts for "y" dimension position errors of the substrate relative to the printer. Also, per numeral 219, in another embodiment, the "trigger" signal used to time the nozzle firing can be adjusted to have the effect of shifting the horizontal lines of the printing grid (see numeral 105 from FIG. 1) to account for position errors of the substrate relative to the printer. Note that gripper "in-scan" or "y-axis" compensation is not required for all embodiments.

[0055] Considering the subject matter of FIG. 2A, by using two or more transducers in a mechanical transport system, it is possible to correct errors in the transport path (e.g., with respect to a nonlinear guide or track or edge). It should be observed that the above-introduced techniques and structures can correct for this repeatable error in the transport path (e.g., the first component 204 of the gripper continues to travel a path disturbed by this error), while the transducer achieves a throw or other correction to nullify this path error in at least one dimension, so that what is being moved (the substrate in this example) travels an idealized path (or at least is made to simulate an ideal edge, as represented by the numeral 109 in FIG. 1). In one embodiment, these corrections are achieved by two or more transducers (e.g., transducers 205 and 206, each independently controllable in a direction (e.g., 210) substantially orthogonal to the direction of the arrow 104), each having a linear throw that is parallel to each other and substantially orthogonal to the direction of the transport.

[0056] These techniques can be applied to virtually any mechanical transport system, but one area that may benefit from these techniques has already been described as being related to industrial printers, where ink droplets need to be deposited at very precise locations. For example, one considered embodiment is as a printer used to fabricate light-emitting devices, such as organic LED display devices (e.g., cell phone screens, HDTV screens, and other types of displays), and "panel" devices, such as solar panels. In this regard, in the applications discussed above (e.g., on which meter-wide and long substrates are printed), some conventional systems rely on air-floating tables to advance the substrate during printing. The ingress and egress of gas in such systems can be carefully controlled to avoid imparting effects to the substrate (e.g., temperature, static electricity buildup, or other effects that may affect the ink behavior) that could potentially cause defects in the finished layer. In other words, gas flow is used to generate a fluid bearing under the substrate, creating a substantially frictionless surface along which the substrate is moved during printing. 2A in such applications can be a single vacuum chuck (as part of second component 207) that effectively engages one contact point on the substrate, or a vacuum gripper featuring multiple vacuum locks that engage individual contact points along the substrate. In such applications, to achieve the "micron-scale" (or smaller) throw used to neutralize nonlinearities and provide precise path advancement, transducers 205 and 206 can advantageously be formed as voice coils that use compression and expansion (i.e., in a direction normal to the direction of the force supported by the floating table's gas bearings) to achieve the microscopic throw used to achieve precise printhead and nozzle alignment with the substrate.That is, with respect to electronic flat panel processing specifically, and with respect to OLED display device processing specifically, the use of a (friction-free) floating support and vacuum grippers is important to minimize defects and maximize device life, and the use of a voice coil as a transducer has been found to provide an effective component for providing the required throw in such systems. However, other types of transducers can also be used to achieve the throw for a particular type of application, for example, through the use of piezoelectric transducers, linear motors, or other types of transducers. In such systems, a floating mechanical pivot mechanism can be used to assist the voice coil in providing the structural linkage and mechanical support for error correction.

[0057] FIG. 2B provides a diagram 221 similar to that of FIG. 1, but further illustrates the goal that can be reached using the mechanism of FIG. 2A. More specifically, FIG. 2B shows the substrate 103 and gripper 203 from FIG. 2A as they advance along the path 107. As in FIG. 1, the path 107 is again assumed to have errors that exhibit some form of curvature or variation, which again may be errors in edge guides, tracks, or other mechanisms, which impart position and / or rotational errors to the gripper 203. However, in this case, the gripper is considered to have a transducer "T" that is controlled to counteract this error, for example in the form of a voice coil displacement that compensates for or equalizes the variation of the path 107. Again, it should be noted that the scale of the errors is greatly exaggerated relative to the scale of FIG. 2B, for example, in practice the path may be meters long (e.g., a 3 meter long substrate is transported through a room-sized printer), while the curvature may be micron or sub-micron in scale.

[0058] It will be recalled from FIG. 1 that at the gripper's position d0 along the path, the original transport path errors were equal to Δx0, Δy0, and Δθ0. However, with respect to the system of FIG. 2B, the transducer is actuated to displace and / or rotate the substrate as seen on the lower right side of FIG. 2B and designated by numeral 103′. That is, the transducer “T” displaces the gripper's second component and the substrate relative to the gripper's first component and track or edge guide 107 to have absolute positions x3, y3, and θ3. In the context of FIG. 2B, the quantity x3 represents an absolute x position that effectively defines a virtual edge 223 offset from the error-disturbed transport path 107, the quantity y3 corresponds to an optional positioning offset of the substrate that offsets it to an arbitrary “smoothed” or normalized advancement relative to the in-scan (or transport) direction, and the quantity θ3 corresponds to a desired angular orientation of the substrate. With respect to the example of FIG. 2B, for the moment it can be assumed that y3 and θ3 are "zero", e.g. the substrate is oriented to be exactly vertical (i.e. squared off relative to the floating support table with no "y" dimension correction, although this need not be the case in all embodiments). In FIG. 2B the printing grating is depicted in numeral 105' to have a consistent x and θ relationship to the substrate 103'. As the substrate is advanced from position d0 to position d1 the transducers are controlled to maintain this consistent positional relationship between the substrate and the normal of the printing grating, i.e. the substrate is aligned to have an absolute position x3 and θ3 (notwithstanding errors along path 107) and is therefore depicted in 103" as having exactly this relationship to the printing grating in 105". It should be noted that in these examples the printing grid is illustrated as maintaining a predetermined relationship to the substrate, however the printing grid is defined by the printhead positioning and substrate and printhead transport system, and what is truly desired is for the printhead and substrate transport mechanisms to maintain a consistent, predetermined relationship to each other, and for the coordinate system established by this linkage to be precisely aligned for each product being processed.In some embodiments, the substrate (or the product being processed thereon) is thus specifically aligned to the printing grid (i.e., to the printer) via a product-by-product or substrate-by-substrate alignment process. This will be further illustrated below. For the moment, it will be assumed that the substrate (e.g., its reference edge, or the juxtaposition of fiducials on the substrate) is maintained in a pre-determined relationship to the printing grid.

[0059] Equations are depicted at various positions in the figure to show how constant positional relationships are maintained. More specifically, it will be recalled that the inherent repeatable errors of the transport path 107 at position d0 were equal to the position and rotation offsets of Δx0, Δy0, and Δθ0. The transducer "T" is therefore controlled to add additional offsets of Δx2, Δy2, and Δθ2, whose values ​​are a function of the pre-measured errors at position d0 along the transport path and at the corresponding transport path position (position d0 along the path 107). That is, in one embodiment, these values ​​are pre-determined (measured) and depend on the negative of the errors Δx0, Δy0, and Δθ0, i.e., they exactly cancel the errors and, optionally, offset the substrate to some pre-determined x / y / θ value. These values ​​can be stored and then used in combination with a pre-determined "recipe" representing the processing of similar products from many substrates to precisely print on each substrate in a series or series of substrates in an assembly line type process. In one embodiment, the depicted transducer "T" only corrects for the substrate position in x and θ (e.g., for any "y" (Dimensional correction is optionally accomplished using one or more other transducers or mechanisms not depicted in the figure.) Note how at position d1, the transducers are controlled to add different offsets depending on the position on the transport path 107, i.e., to add offsets of Δx4, Δy4, and Δθ4. As depicted in FIG. 2B, the values ​​x5 and θ5 can be exactly equal to the values ​​x3 and θ3, but again, this need not be the case in all embodiments.

[0060] It should be noted that in one contemplated embodiment, the printer's support platen (i.e., the floating table in the example discussed above) has predetermined optical markings that provide a positional reference system for the printer, i.e., the printing grid is linked to and defined relative to this system. The optical markings can be, for example, physically formed on the support table or added, for example, via adhesive tape.

[0061] Micron-scale or better position control is in many ways not as intuitive as it may seem; for example, in one embodiment, the gripper transport system and the printhead transport system each carry a camera that is used to find a common registration mark and thereby establish the origin of a coordinate system that matches the two transport paths. This process, and the transport systems for each printhead and substrate in such a system, effectively define the printer's coordinate reference system (and in large part determine the configuration of the printing grid according to which droplets can be deposited). U.S. Provisional Patent Application No. 62 / 459,402, already incorporated by reference, provides information regarding the use of these cameras, position detection, and associated calibration. Essentially, in addition to finding a common coordinate point (or "origin") in one disclosed system, each transport system uses optical tape and optical sensors to provide precise (e.g., micron-scale) position detection and feedback, so that the transport system (e.g., the first component of the gripper) "knows" exactly where it is relative to the printer's coordinate system, and these various components work together to effectively define the complete printer coordinate system. In fact, use of such a system can eliminate the need for y-dimension gripper path corrections, e.g., the gripper is simply driven to a specific position value along the y dimension.

[0062] Once the "origin" is established by the referenced camera alignment process, the two transport systems are articulated to determine the relative coordinates between each transport system camera and a transport system reference point (e.g., corresponding to a printhead nozzle position), which then allows for precise identification of any point relative to the printer's coordinate system. As previously mentioned, in such a system, the printer's "understanding" of the drop landing location depends on the printing grid, which in turn is defined by this coordinate system. Transport path motion errors in such a system can potentially lead to a situation where a particular printing grid location (e.g., associated with an understanding of a specific combined gripper / printhead position) deviates from the actual positions of these components. By correcting the transport path errors in the manner described herein using the various devices described herein, this allows the system to correct its path errors such that the substrate and printhead are each positioned in a manner corresponding to the printing grid assumption. In fact, even errors such as minor non-orthogonality between the transport paths can be corrected using optional rotation offsets (e.g., non-zero values ​​of θ3 and θ5), as described above for the pre-recorded error measurements.

[0063] 2B, then each substrate introduced into the system has one or more fiducials identified and used to precisely understand the position of the substrate (or the panel product thereon) during printing. As each substrate is introduced, its fiducials can be detected (e.g., using one or more of the cameras) and a mechanical system can be used to properly orient / align the substrate to correspond to the expected position (note that this process is not necessary for all embodiments, e.g., it is also possible to adjust the printer control information to accommodate known substrate misalignments or angular misorientations).

[0064] During the calibration process, the test substrate can be advanced through the printer in a manner corresponding to the desired recipe. An optical inspection device (e.g., a camera) can be used along with image processing techniques to precisely measure position and rotation errors in each dimension of interest. Movement and / or printing then occurs according to the desired recipe, and optical inspection is performed continuously or intermittently to measure position and orientation errors as the substrate is advanced, e.g., to detect repeatable errors that deviate from the expected position / orientation as determined for each advance of the transport system (along their respective paths). These errors and / or corresponding corrections are then stored in the system's digital memory (e.g., in an SSD, RAM, or other non-transitory medium) in a manner indexed according to the transport path position (e.g., the position of the first component of the gripper along the path 107), according to time, or in another manner. As implied, the measured errors are used to generate repeatable error correction values ​​of the transducer.

[0065] During "live printing" of substrates in an assembly line type process, the fiducials on each substrate are then used again to determine each substrate's precise position relative to the printer and / or to realign / reorient the substrate as was done with the test substrate. The stored transducer corrections are then read from the memory according to the gripper / printhead assembly measured positions and used to drive the transducers of the error correction mechanism (printhead and / or gripper) to provide compensatory motions that precisely position the substrate relative to the printhead. During printing, the printhead and gripper positions are continually used along with the stored pre-determined error measurements / corrections to drive the substrate to its correct "cross-scan" position (and / or other position or orientation) relative to the floating table and printhead.

[0066] The bottom portion of FIG. 2B illustrates how two linear transducers (e.g., voice coils) on the gripper can correct for rotational errors and positionally offset the substrate in a manner that corresponds to an idealized edge (e.g., via displacement in the “x” dimension). More specifically, a local portion of the transport path is designated by numeral 227 as having a significant amount of curvature that deviates from the idealized straight edge 109 of the transport path. At two effective contact points between the substrate and the transport path (designated “c1” and “c2”, respectively), the errors are assumed to be “xi” (depicted as an offset relative to the idealized straight edge in the negative direction) and “xj” (depicted as an offset relative to the idealized straight edge in the positive direction), respectively. Here, it is assumed that it is desired to precisely position the left edge of the substrate (or printable area of ​​the substrate) at an absolute position “xk” from the idealized transport path (e.g., corresponding to the depicted virtual edge 223). The numerals 105' represent a slight offset of the printing grid to accommodate the entire range of "x" position errors imposed by the system, and optionally provide some slight buffer. To achieve this correction, the positive errors (i.e., xi) at position "c1" are further offset by an amount "xk-|xi|", while the negative errors (i.e., xj) at position "c2" are further offset by an amount "xk+|xj|". The two depicted transducers "T" are controlled for this purpose, thus straightening the substrate to an idealized straight edge. Similar corrections are performed at all other times during the movement of the gripper along the transport path 107, depending on the errors at the relevant positions, i.e. so that the substrate follows a virtual path associated with the absolute position "xk".

[0067] Several points should be noted with respect to this discussion. First, the gripper 203 Although depicted in this figure as a single unit, in reality it may consist of many parts (e.g., the first and second components discussed above, or a distributed series of two, three, five, or another number of grippers or gripper components that engage the substrate at different locations). Second, while in this embodiment two transducers are depicted as parallel linear actuators (e.g., voice coil or piezoelectric transducers, respectively), this is not required for all embodiments. That is, depending on the embodiment, the transducer "T" may be coupled in series and may be a rotary, linear, or other type of actuator. In still other embodiments, more or less than two transducers may be used. Third, it should be noted that in various other embodiments or implementations, the correction imparted by the transducer as a function of the transport path position may be derived and / or applied in a number of ways. In a first embodiment, a test device (e.g., a test substrate) having a position sensor (e.g., optical, high frequency, or other detector) is advanced along the transport path in an offline process and continuously measured for position and / or rotational errors that are recorded as a function of advancement along the transport path. A series of time-based or position-based corrections can then be developed and formatted as control signals for the transducers. Then, during manufacturing (or other run-time use of the transport path), inputs corresponding to positions along the transport path are received (e.g., time measurements, position measurements, analog or digital signals, or some other values) and used to look up or index the appropriate transducer control signals, which are effectively "reproduced" or otherwise applied depending on the transport path position (and potentially multiple transport path positions). Finally, as noted above, various mechanisms exist for identifying positions along the transport path, for example, signals (e.g., drive signals, timing signals, etc.) can be used for this purpose, as represented by numeral 228, or position sensors 229 can be used.In one specifically contemplated embodiment, as referenced above and discussed in U.S. Provisional Patent Application No. 62 / 459402, a position marking system and a position detector are used for each transport path to measure associated positions (e.g., for print head transport and substrate transport). Obviously, many alternatives are possible.

[0068] As already referenced, a processing device or system can have multiple transport paths. In the context of a split-axis printer, in one embodiment, as already referenced, the printer coordinate reference system can be defined depending on separate print head and substrate transport paths. FIG. 2C is used to discuss position errors resulting from inaccuracies in a second transport path, such as the print head transport path. Such a situation is generally depicted by numeral 251 in FIG. 2C. The substrate is advanced by the gripper in a first dimension (represented by arrow 104), and the print head is advanced along a second transport path 256 in a second dimension (represented by arrow 254). At a first position 253 of the print head along the second transport path, the print head is subject to errors Δi0, Δj0, and Δφ0. Note that the variables i, j, and φ represent the x and y offsets (and angular rotation in the xy plane), but i, j, and φ are used instead of x, y, and θ to distinguish this embodiment from that of the gripper transport system. As the print head is advanced to position 253', as represented by phantom lines on the right side of the figure, the errors are Δi1, Δj1, and Δφ1. Again, this error is a function of position along the transport path 256, and the change in error is potentially linear or non-linear. If left uncorrected, this error can also distort the print and cause manufacturing accuracy problems as already referenced. In this embodiment, any motion of the substrate 103 relative to the gripper transport path is assumed to be corrected using the depicted gripper 203 (and its transducer "T"), but the problem is that the print head traveler can also generate errors, resulting in x, y, or θ errors of the print head, changing the expected landing position of the droplets ejected from the print head nozzles. The effects of these errors are illustrated relative to the intended printed grid 257, as indicated by arrow 255; i.e., the effect of unintended printhead rotation (and / or unintended "x" dimension displacement) is seen via a distorted printed grid 257' (in a similar manner, unintended printhead rotation displacement in the "y" dimension would effectively result in "squeezing together" the vertical printed grid lines).

[0069] In relation to the figure, it is also desired that the print head undergo ideal motion, i.e. motion that is not characterized by unintended mechanical errors. That is, in this embodiment, it is also desired that the print head follow a virtual ideal (e.g., linear) transport path 225 that would effectively correspond to an unperturbed printing grid (e.g., represented by numeral 257). This is accomplished in one embodiment by inducing both a virtual "ideal" gripper motion, represented by vertical line 109, and a virtual "ideal" print head motion, represented by horizontal line 225.

[0070] In much the same manner as the gripper path correction, the transport system for the printhead transport path can also optionally use a set of transducers to facilitate idealized printhead positioning. To this effect, the transducers advantageously provide a displacement to an arbitrary "absolute" position that accommodates the entire range of printhead "y" position errors, optionally providing some slight buffer, so that the printhead motion corresponds to a virtual path 269, which also provides a fixed, known position that corresponds to the "offset" printing grid (105' from FIG. 2B).

[0071] FIG. 2D provides an illustration of a system 261 intended to correct for this type of error. That is, FIG. 2D shows a second transport path 256 used to support lateral movement of one or more printheads in the general direction indicated by arrow 254. The printhead assembly includes a first component 263 that rides (e.g., along a track or guide) along the transport path 256 and a second component 264 that carries the printheads. These first and second components are operatively coupled by one or more transducers 265. The transducers are linear actuators, in this embodiment, each supporting a micro-throw that offsets the second component in the "y" dimension, and common mode and differential mode drive are again used to selectively achieve linear displacement and / or xy plane rotation (θ). As represented by both numerals 267 and 267' (representing the printhead at distinct positions along the "cross-scan" or "x" dimension, respectively), the corrections allow the printhead to follow a hypothetical ideal path 269 that is not characterized by mechanical errors (i.e., even though the first component 263 continues to travel the error-impeded second transport path 256). Similar to the gripper embodiment, the transducers of FIG. 2D can be controlled to offset the printhead to an absolute y position (i.e., corresponding to line 269) such that when the printhead is at position 267, the aforementioned errors of Δi0, Δj0, and Δφ0 are further offset by Δi2, Δj2, and Δφ2, and when the printhead is at position 267', the transducers are controlled to offset the printhead and add offsets Δi4, Δj4, and Δφ4. i and φ typically have constant values ​​at positions 267 and 267', and are also typically both zero, although again, this is not required for all embodiments. As with the previous gripper example, the depicted transducer configuration is merely exemplary and different transducers (e.g., rotary transducers) can be used and can be adapted to different conveying systems and / or dimensions.Additionally, as with the previous examples, the depicted converter offsets the printhead, in this embodiment using both common and differential mode control to achieve a floating pivot point. The result is that the desired "error-free" transport path 225 is offset to an arbitrary position 269 that is sufficient to encompass any "y" or in-scan dimension jitter resulting from imperfections in the second transport path 256. The result of these corrections (and optional use of gripper corrections as already referenced), as indicated by numeral 255', effectively normalizes the print grid, as indicated by numeral 257". Note that it is also possible to use another converter 273, as referenced by function box 271, to offset the position of part or all of the printhead assembly and correct for cross-scan position errors, as well as drive signal correction techniques 275.

[0072] Considering the principles discussed thus far, correcting each of the substrate paths to a "virtual" linear edge, and the printhead paths to a "virtual" linear edge, allows both the substrate and the printhead to be positioned in a manner that conforms to the printing grid assumptions (e.g., the printer's coordinate reference system) despite the minute errors imparted by the mechanical system. These techniques may optionally be combined with drive control techniques (or other described techniques for correcting each transport along that transport dimension) to further improve system accuracy. Again, these techniques can also be extended to other motion dimensions and processing and / or mechanical systems.

[0073] FIG. 2E presents another example 281, i.e., an alternative embodiment in which errors in one transport path can be corrected using one or more transducers “T” associated with a second transport path. In this case, the gripper assembly 203 can be assumed to include two linear transducers, again controlled in common and differential drive modes to achieve cross-scan offset and rotation correction without a fixed pivot point. Note that in this case, the errors are again on the scale of microns or nanometers. The depicted angles and offsets are therefore greatly exaggerated in the figure to aid in explanation. In this case, the figure shows “two grippers” 203, which in fact represent the exact same gripper and the position of the gripper along the “in-scan” dimension for two different scans. However, in this case, one of the transport paths (i.e., path 256 with respect to the printhead assembly) does not have its own error correction system. The gripper error correction system is therefore also controlled to correct the printhead transport path errors, in this case by linearly superimposing offsets correcting the printhead transport system on those corrections used to correct the scan-dependent gripper path errors. That is, in this embodiment, it should be assumed that the two grippers represent two alternative sets of transducer control signals that respectively correct the printhead system errors {Δi0, Δj0, and Δφ0} at printhead position 273' and the printhead system errors {Δi1, Δj1, and Δφ1} at printhead position 273" (i.e., corresponding to the individual scans). That is, even though it is assumed that the gripper transport in the "y" dimension is corrected to an ideal edge (with respect to the gripper transport path) through the use of mitigation offsets and angles provided by the transducers of the gripper system in relation to FIG. 2B, in one embodiment, these same transducers may also be used to correct errors in the printhead path (or another individual transport path).As depicted, further offsets and / or rotations are added to effectively reposition the substrate so that it has its intended position and orientation relative to the print head (e.g., to produce motion in a manner that matches print head errors, as represented by alternate transformed edges 107'" and 107"").

[0074] As the discussion above implies, while the previous example shows the correction of errors in two transport paths, the principles described with reference to FIG. 2E can be applied to correct fine errors in any number of transport paths, e.g., one, two, three, four, five, etc., with corrections for multiple transport paths being applied to a single drive path (e.g., to a transducer used for substrate transport) or to a second, fewer drive paths. The discussion also applies to non-orthogonality, e.g., where the gripper and printhead transport paths are not exactly 90 degrees apart. This can be treated as equivalent to the case of measured printhead x-position dependent errors. Also, while the term "transport path" is illustrated in the figures as a position change along a curved path, the principles and fine error correction procedures discussed above can also be applied to correct fine errors in any transport dimension (i.e., including rotation and precise angular orientation), e.g., in embodiments where the mechanism is rotated, it is possible to measure the angular rate of change or "jitter" of the orientation and use transducer and / or drive signal corrections as illustrated above to correct such fine errors.

[0075] II. Measuring and / or detecting errors in processing equipment and combating them FIG. 3A is a flow chart depicting a method step 301 that implements some of the techniques introduced above. As represented by numeral 303, the method can be embodied in a system having a transport path where it is desired to correct fine motion, position, or orientation errors of the motion system. For example, the system can perform high-precision product "assembly line" manufacturing using printers for material deposition, as introduced above. Errors are measured by numeral 305, optionally in more than one dimension or for more than one transport path, as indicated by numeral 307. Either the errors or associated corrections applied to one or more transducers are then stored in a digital memory by numeral 309 as a function of the path position (or as a function of another similar reference, e.g., elapsed time, drive signal, temperature, etc.). As indicated by numeral 311, in one embodiment, the path position is optically detected using a camera or other optical sensor. For example, as already referenced, in a split-axis precision printing system, such a sensor can be used to measure marks on an adhesive tape adjacent to the transport path, for example with a registration mark every 1 micron of progression along the transport path. During transport (e.g., during product manufacturing), the stored errors and / or corrections are read from the memory depending on this position and / or other factors and used to drive one or more transducers to achieve position and / or orientation corrections, as per numeral 313. As represented by numerals 315 and 317, in one embodiment, there can be multiple transducers, each configured to achieve parallel micro throws, optionally without fixed pivot points, as introduced in FIG. 2A. The result is that what is being transported follows a virtual ideal path, as already referenced and identified by numeral 319.

[0076] FIG. 3B shows that the techniques presented above can be embodied in many different forms to correct transport path errors, generally as represented by numeral 351. In the context of a printer for manufacturing applications, a print recipe can be pre-stored or cached in a manner that will be used to reproducibly print on many substrates on a continuous basis as part of an assembly line type process, for example, as indicated by numeral 352. As a non-limiting example, the techniques described herein can then be applied to correct repeatable fine motion errors along paths corresponding to the motion of the substrate, the motion of one or more printheads or printhead assemblies, the motion of a camera assembly or inspection tool, and the like. Other factors such as temperature, printhead position, and the like can also be used. These techniques enable automatic correction of motion along these transport paths for fine errors such that the motion of the substrate (or optionally any of these systems) is made to correspond to an ideal path, even though the actual transport drive mechanisms (e.g., motion of grippers, edge guides, travelers, and the like) are still disturbed by path errors that impart unintended offsets, nonlinearities, and other errors. Generally speaking, corrections are made by a subsystem independent of the print recipe, in a manner that allows for print planning and assumes the substrate is ideally placed. For example, the structures described herein provide, in one embodiment, a means for countering an error or unintended offset "Δx" in a first dimension relative to the transport path, where the first dimension is independent of the transport path (meaning it includes at least one component orthogonal to it). Such a means may be implemented by adjusting the transport path position in response to the transport path position to reduce or eliminate "Δx", as represented by numeral 353 in FIG. 3B. Such means generally comprise at least one transducer, electronically controlled to effect positional displacements depending on the position along the transport path and / or other factors. As represented by numeral 354, these structures (or different, potentially overlapping sets of structures) can provide means for defining a virtual edge at a specific, arbitrary location in a first dimension (e.g., at "x3" in the embodiment from FIG. 2B) and offsetting the gripper component to such location relative to the transport path (or the structure being transported). As before, such means also generally comprise a transducer and associated hardware and / or instruction logic that causes the transducer to nullify or equalize errors. By numeral 355, in another embodiment, the structures described herein provide means for countering errors "Δy" in a second dimension relative to the transport path. This second dimension is optionally independent of the transport path, but can (alternatively) represent a common dimension to the transport path, or may otherwise be generally synonymous with the transport path. Such means may comprise at least one transducer controlled in response to the transport path position (and / or other factors) to reduce or eliminate "Δy", such as by correcting the position of the "thing" being transported or to otherwise adjust the speed or motion along the transport path, for example, with respect to the embodiment depicted above. In yet another variation, the same structure that may be applied to counter "Δy" by numeral 356 may provide a means to define a virtual edge at a specific (absolute or relative) position in the second dimension (e.g., at a non-zero "y3" for the embodiment above) and offset the transport path (or the structure being transported) to such position. Such means also generally comprise a transducer and logic that causes the transducer to achieve a positional displacement in response to a position along the transport path. In one embodiment, the means may encompass another transport path or associated error correction system, such as an error correction system associated with printhead transport (e.g., to compensate for nozzle firing time, substrate, printhead or other position errors, or other sources of error).In yet another embodiment (357), a transducer similar to that discussed above can be applied to counter rotational errors (Δθ). In one embodiment, the means can comprise a single transducer that converts electrical energy into structural rotation, while in other embodiments, two or more position transducers can be applied in the same vein. For example, as discussed above, one implementation can use two voice coils, each a linear transducer that, when operated independently, provides rotational adjustment of what is being transported, with a floating mechanical pivot mechanism used to support the voice coils and provide structural rigidity. These structures (or different, potentially overlapping sets of structures) can also provide means for defining (358) virtual edges in specific (absolute or relative) angular relationships to the first and second dimensions discussed above (e.g., in “θ3” in the above embodiment), and for offsetting the transport path (or the structure being transported) in a manner corresponding to such orientation. In yet another embodiment (359), the structure described herein provides a means for accommodating an offset "Δz" in a third dimension relative to the transport path, the third dimension being optionally independent of the transport path and the first and second dimensions referenced above. Such means may again comprise at least one transducer controlled by hardware and / or software logic in response to the transport path position to reduce or eliminate errors. The transducer and supporting logic may also be used to define a virtual edge in Z3 (360). Per numeral 361 and associated set of ellipses, these techniques may be applied to multiple degrees of freedom, including corrections and / or offsets in any of the three positional dimensions and any of the three rotational dimensions (i.e., yaw, pitch, and / or roll). In some embodiments, as represented by numeral 363, a means for correcting misalignment may be applied to align the substrate to the printer's reference system. Such means may include position sensors such as cameras, handlers or other transport devices, processors, and associated supporting instructions and / or hardware logic.The means for correcting errors in and / or aligning the print head (PH), per numeral 365, may include a converter with a floating pivot point and / or support for common and differential correction modes, as referenced above. The means for recording errors (or correction controls for the converter), per numeral 366, may comprise hardware and / or instruction logic and memory. The system may also include means (367) for combining error and / or correction signals to correct multiple sources of error (e.g., for multiple transport paths).

[0077] It should be noted that each reference to a dimension, e.g., "x", "y", "θ", or other dimension, is arbitrary, i.e., they may refer to any dimension and are not limited to Cartesian or rectangular or rectilinear coordinates. In one embodiment, the "x" and "y" dimensions correspond to the "cross-scan" and "in-scan" dimensions, respectively, of the processing system, although this need not be true in all embodiments.

[0078] By correcting for motion errors in such a manner, the described processes provide a "virtual" and / or ideal and / or straight transport path even though the mechanical motion system may still be disturbed and continue to follow existing repeatable imperfections. When applied in the context of manufacturing systems such as the aforementioned industrial printers, these techniques provide a powerful tool to enable precision positioning and manufacturing.

[0079] FIG. 4A depicts a substrate 401 along with several dashed boxes representing individual panel products. One such product, seen at the bottom left of the figure, is designated using reference numeral 402. Each substrate (in a series of substrates) has, in one embodiment, several registration marks as represented by numeral 403. In one embodiment, two such marks 403 are used on the substrate as a whole, allowing measurement of substrate position offset relative to mechanical components of the printer (e.g., grippers), while in another embodiment, three or more such marks 403 are used to facilitate additional adjustments (e.g., rotational adjustments). In yet another embodiment, each panel (such as any of the four depicted panels) is accompanied by a per-panel registration mark such as mark 405, this latter approach allowing gripper adjustments so that each panel being printed is precisely aligned to the printer's coordinate reference system. Whatever approach is used, one or more cameras 406 are used to image the registration marks to identify the substrate position relative to the printer's coordinate reference system. In one contemplated embodiment, a single stationary camera is used, and the printer's transport mechanism (e.g., a handler and / or air float mechanism) moves the substrate to sequentially position each registration mark within the field of view of the single camera. In different embodiments, the camera is mounted on a motion system for transport relative to the substrate (e.g., the printhead assembly as discussed above). The camera can be mounted on a common assembly of printheads or a second assembly, on a common traveler used for printhead transport, or on a completely independent traveler, depending on the embodiment. In yet other embodiments, low and high magnification images are taken, the low magnification image roughly locating a fiducial for the high resolution magnification, and the high magnification image identifying a precise fiducial position according to the printer coordinate system. Line or CCD scanners can also be used. Considering the previous discussion, in one embodiment, the printer's transport mechanism (and associated feedback / position detection mechanism) controls the motion to within about 1 micron of the intended position, and an imaging system is used for each substrate to align (and optionally mechanically reposition) the substrate to the printer's coordinate reference system.A pre-recorded error or transducer correction signal can then be applied to correct the repeatable motion error in the manner described.

[0080] In a typical implementation, printing will be performed to deposit a given layer of material over an entire substrate at once (i.e., with a single printing process providing layers for multiple products). Such deposition can be performed within individual pixel wells (not shown in FIG. 4A; i.e., there would typically be millions of such wells for a television screen), such as depositing an emissive layer within such wells, or on a "blanket" basis, such as depositing a barrier or protective layer such as an encapsulation layer. Regardless of which deposition process is in question, FIG. 4A shows two illustrative scans 407 and 408 along the long axis of the substrate. In a split-axis printer, the substrate is typically moved back and forth (i.e., in the direction of the depicted arrows) with the printer advancing the printhead positionally (i.e., perpendicular to the page of the drawing) between scans. Note that while the scan path is depicted as linear, this is not required in any embodiment. Also, while the scan paths (e.g., 407 and 408) are illustrated as being adjacent and mutually exclusive in terms of area covered, this is also not required in every embodiment (e.g., the print head can be applied on a portion-by-portion basis to swaths of printing as needed or desired). Finally, note also that any given scan path will typically pass across the entire printable length of the substrate, printing layers for multiple products in a single pass. Each pass uses nozzle firing decisions according to a printing recipe, and control over the transducers (not shown in FIG. 4A ) is used to ensure that each drop in each scan is deposited precisely where it should be deposited relative to the substrate and / or panel boundaries.

[0081] FIG. 4B illustrates one contemplated multi-chamber processing apparatus 411 that can be used to apply the techniques disclosed herein. Generally speaking, the depicted apparatus 411 includes several general modules or subsystems, including a transfer module 413, a printing module 415, and a processing module 417. Each module maintains a controlled environment so that printing can be performed, for example, by the printing module 415 in a first controlled atmosphere and other processing can be performed, for example, another deposition process, such as an inorganic encapsulation layer deposition (for the printed material, for example) or a curing process, in a second controlled atmosphere. These atmospheres can be the same, if desired. The apparatus 411 uses one or more mechanical handlers to move substrates between modules without exposing the substrates to an uncontrolled atmosphere. It is possible to use other substrate handling systems and / or specific devices and control systems within any given module that are adapted to the processing performed for that module. Within the printing module 415, as discussed, mechanical handling can include the use of floating tables, grippers, and alignment / micro-error correction mechanisms (in a controlled atmosphere), as discussed above.

[0082] Various embodiments of the transfer module 413 can include an input load lock 419 (i.e., a chamber that provides buffering between different environments while maintaining a controlled atmosphere), a transfer chamber 421 (also having a handler for transporting the substrate), and an atmospheric buffer chamber 423. Other substrate handling mechanisms, such as a floating table, can be used within the print module 415 for stable support of the substrate during the printing process. In addition, an xyz motion system (such as a split axis or gantry motion system) can be used to reposition and / or realign the substrate to the printer, to provide precise positioning of at least one print head relative to the substrate, and to provide a y-axis transport system for transport of the substrate through the print module 415. It is also possible within the print chamber to use multiple inks for printing, e.g., using separate print head assemblies, so that, e.g., two different types of deposition processes can be performed within the print module in a controlled atmosphere. The printing module 415 includes a gas enclosure 425 that houses the inkjet printing system along with means for introducing a non-reactive atmosphere (e.g., nitrogen or a noble gas) and otherwise controlling the atmosphere for environmental conditioning (e.g., temperature and pressure, gas composition and the presence of particulate matter). It is possible.

[0083] Various embodiments of the processing module 417 can include, for example, a transfer chamber 426, which also includes a handler for transporting the substrate. In addition, the processing module can also include an output load lock 427, a nitrogen stack buffer 428, and a curing chamber 429. In some applications, the curing chamber can be used to cure, bake, or dry the monomer film into a uniform polymer film. For example, two specifically contemplated processes include a heating process and an ultraviolet radiation curing process.

[0084] In one application, the apparatus 411 is adapted for mass production of liquid crystal display screens or OLED display screens, for example, fabricating an array of (for example) eight screens at a time on a single large substrate. The apparatus 411 can support an assembly line type process such that a series of substrates are processed in succession, one substrate being printed on and then advanced for curing while a second substrate in the series is simultaneously introduced into the printing module 415. The screens produced in one embodiment can be used in televisions and as display screens for other forms of electronic devices. In a second application, the apparatus can be used in the mass production of solar panels in much the same manner.

[0085] The printing module 415 can be advantageously used in such applications to deposit organic light-emitting layers or encapsulation layers that help protect sensitive elements of an OLED display device. For example, the depicted apparatus 411 can be loaded with a substrate and controlled to move the substrate between various chambers in a manner uninterrupted by exposure to uncontrolled atmosphere during the encapsulation process. The substrate can be loaded via an input load lock 419. A handler located in the transfer module 413 can move the substrate from the input load lock 419 to the printing module 415, and after completion of the printing process, the substrate can be moved to a processing module 417 for curing. By repeated deposition of subsequent layers, each of controlled thickness, a cohesive encapsulation can be built up to suit any desired application. Again, it is noted that the techniques described above are not limited to encapsulation processes, and many different types of tools can be used. For example, the configuration of the apparatus 411 can be varied to place the various modules 413, 415, and 417 in a different juxtaposition, and additional fewer or different modules can also be used. In one embodiment, the depicted apparatus 411 can be coupled with other modules and / or systems to potentially produce other layers of a desired product (e.g., via different processes). When the first substrate in the series is completed (e.g., processed to deposit materials that will form the layer at issue), another substrate in the series is then introduced and processed in the same manner, e.g., according to the same recipe.

[0086] Figure 4B provides one example of a set of linked chambers or processing components, but clearly other possibilities exist. The techniques introduced above can be used to control processing processes performed with the device depicted in Figure 4B, or indeed by any other type of deposition equipment.

[0087] Once printing is completed, the substrate and wet ink (i.e., deposition liquid) can then be transported for curing or processing of the deposition liquid into a permanent layer. For example, briefly returning to the discussion of FIG. 4B, the substrate can have the "ink" applied in the print module 415 and then transported to the curing chamber 429, all without disrupting the controlled atmosphere (i.e., advantageously used to prevent moisture, oxygen, or particulate contamination). In a different embodiment, an ultraviolet scanner or other processing mechanism can be used in situ, for example on a split axis traveler in much the same manner as the print head / camera assembly described above.

[0088] FIG. 4C specifically illustrates process flow 431, this time rooted in the context of a split-axis printer 433. Various process options are illustrated in option blocks 434-437, such as the use of liquid monomers as "inks", the use of a printer enclosure that allows printing to occur in the presence of a controlled atmosphere (for the purpose of minimizing the presence of unwanted particulate matter and / or moisture along with the deposited ink), the use of multiple printheads, cameras, UV light, or other assemblies, and the use of an "assembly line" type process, through which multiple substrates would be passed in succession and subjected to the same manufacturing process. Process blocks 439-456 refer to offline calibration processes that are used to pre-measure repeatable errors within the environment of such a printer. For example, with respect to the transport path in which the errors are measured, the transported object is introduced and, optionally, suitable sensors are mounted thereon to measure position and / or rotation errors, as per numeral 439. This is not required for all implementations; for example, in one system, a calibration process advances the gripper in incremental amounts and then uses an optical detection system (e.g., assuming a high resolution camera) to measure the exact position of the substrate fiducials, and interpolation 447 is applied to derive the error corresponding to any intermediate positions. In another contemplated embodiment, the gripper (e.g., the "second component" of the gripper) is equipped with an optical device (e.g., a set of mirrors) that redirects a laser beam, and one or more targets are used to continuously detect the magnitude of the "x error" "on the fly" as the gripper is advanced. Clearly, many options will occur to those skilled in the art.

[0089] Whatever error detection system is used, a particular transport path is then driven in accordance with the desired printing process 441 and the position of what is being transported is measured 443 (e.g., to register the advancement along the transport path and correlate that advancement with minute errors with each advancement of the test substrate). As indicated by the optional blocks on the right side of the diagram, exemplary processes include the use of a position signal 444 (e.g., an analog or digital signal representative of the drive of what is being transported), the use of a position sensor 445, and / or the use of another mechanism for deriving a position 446. Per numeral 449, for each position along the transport path in question, errors and / or corrections are calculated and used to generate transducer control signals that are recorded 451 in non-transient storage device 452 in a manner ideally indexed 453 to the transport path position or advancement and / or other factors (or to positions for multiple transport paths, e.g., depending on the current gripper position and printhead assembly position). In keeping with the previous example, where the gripper is advanced according to a digital position signal, the error correcting transducer control signals can be stored in a manner indexed by the digital value of the digital position signal associated with the gripper, with similar values ​​optionally registered as a function of each other transport path position and / or other factors of interest. For embodiments having multiple transducers, each independently driven according to path position, the control signals for each transducer can optionally be stored as parallel tracks 454. As further indicated by numeral 455, the transducer control signals can also optionally be calculated in a second or additional iteration for each independent translation mechanism (i.e., such that control signals are generated for each set of transducers, e.g., a set of corrections for the gripper's error mitigation system and a set of corrections for the printhead assembly's error mitigation system). In situations where one error correction system is to correct multiple transport paths, an array of correction signals can then be stored as a function of position along all associated transport paths.In an embodiment as described above where error mitigation is performed by the correction system for one transport path to cover errors in multiple transport paths, the correction signal may be superimposed (or otherwise generated according to a formula or equation) according to each associated transport path position, e.g., error(i,j)=fn{gripper:pos(i),printhead assembly:pos(j)}. Other examples will occur to those skilled in the art. When the correction is a function of multiple transport path positions, as represented by numeral 456, pre-computation of the correction signal may optionally include iterations of motion / error measurements for each transport path position or for each individual transport path position combination, treating each transport path position as an independent degree of freedom.

[0090] A dashed line 457 is used to separate the offline calibration tasks (above the line) from the run-time tasks (below the line).

[0091] During run time, each new production substrate is introduced and aligned 459, e.g., to have a normalized relationship in each of the x, y, and θ dimensions. Each transport path (e.g., substrate, print head, etc.) is then driven according to preprogrammed printing instructions, i.e., recipe dependent, per numeral 460. The position (and each other associated variable, as appropriate) of each transport path's (e.g., substrate, print head, etc.) per numeral 461 is then used to directly index memory 462 to retrieve errors, position values, transducer drive values, or any other values ​​from which a correction and / or desired position can be identified or calculated. Any type of memory suitable for these purposes and for rapid access can be used, e.g., hard drives, solid state storage devices, random access memory, flash memory, content addressable memory, etc., as per the particular design. In another embodiment, the formulas can be stored and provided to a processor or other circuitry for calculation of errors / offsets at run time, as described. Transducer corrections are then output as a function of the transport path position to provide a virtual complete transport path or edge, per numeral 463. If a particular embodiment is to correct multiple transport mechanisms or transport dimensions as part of this process, then each associated correction and / or transducer control value can be optionally superimposed and / or otherwise combined at this point to produce a correction of the aggregate error 465 of the multiple transport paths. Per numerals 466 and 467, in one optional design, the system corrects yaw and translation errors (e.g., "x", "y", and "θ") in each transport path, while in another embodiment, the transport drive signals for one or more of the transport paths can be modified (e.g., to correct imperfections that cause translation errors in the primary transport dimension). The transducers are then driven appropriately 468 to even out mechanical imperfections in one or more of the transport paths. As previously mentioned, in one embodiment, the transducers can include linear transducers that each offset the substrate normal to the gripper path transport, per numeral 469.In another embodiment, the offset can create a "virtual edge" 471, and in yet another embodiment 472, the converter can be used to offset auxiliary paths (e.g., print head path, gripper drive, etc.). Printing is performed on the realigned substrate and the process ends, that is, until the next substrate is introduced 473. As should be apparent, these processes provide a repeatable process that can be used to process each substrate in a series.

[0092] FIG. 4D provides another flow chart for system operation, this time for system alignment, where a series of steps are generally designated using numeral 475. The method begins with system initialization, by numeral 476. For example, this initialization can be performed at each power-up, or on an ad-hoc (e.g., operator command) or periodic basis. An alignment / detection operation 477 is then performed, for example, for the various transport paths to identify an origin or common reference frame, as already indicated. As shown on the left side of the figure, this operation (or system initialization) can be performed when desired, for example, after a maintenance operation, resulting in a change of printhead or other system components. Note that numeral 478 represents a typical printhead assembly configuration, i.e., an assembly carrying nine printheads (this may be one large assembly or several subassemblies, e.g., three "ink sticks", each carrying three printheads in an interleaved configuration). In one embodiment, there may be 256 to 1,024 nozzles per printhead. Optionally, once each printhead has been filled, calibration then continues at 479, with the gripper system's "up facing" camera being used to image the underside of the printhead and measure the exact x,y location of each nozzle according to the printer's coordinate reference system at 481. That is, each printhead can feature one or more fiducials that are detected and then used to identify each nozzle using search algorithms and image processing techniques. If necessary, the printhead position can be adjusted (e.g., the spacing between printheads is adjusted) through the use of stepper motors or mechanical adjustments. As referenced by provisional patent application Ser. No. 62 / 459402, already incorporated by reference at 483, a camera system carried by the printhead assembly can likewise be used to identify the location of the gripper's "up facing" camera to facilitate these various position detection functions.

[0093] As each substrate is introduced 485, the substrate's position is precisely identified and used to align the substrate (and any product being processed thereon) to the printer's coordinate reference system. The new substrate is loaded 487 and roughly aligned with the printer's transport system (e.g., edge aligned or otherwise using an initial transport process). A "downward looking" camera system carried by the printhead assembly is then employed 489, using a search algorithm and suitable image processing, to precisely locate one or more substrate fiducials. For example, this detection can be performed using a spiral search pattern or similar search pattern that searches for a fiducial expected position until a precise fiducial position and / or orientation is found. A series of optional and / or alternative correction processes can then be employed to precisely position the substrate. For example, as variously indicated by process box 491, in one embodiment, the aforementioned transducers can be driven to provide precise substrate positioning (e.g., the vacuum lock of the gripper's "second component" is not adjusted, but the transducers are ganged in common drive mode and / or differential drive mode until the substrate datum has exactly the correct starting position and orientation). The transducer position corresponding to this substrate position / orientation can then be used as a zero level or position, and error corrections (during production) are then superimposed on top of it. Alternatively, or in addition, a mechanical handler can be used to reposition the substrate as needed. As yet another alternative, the recipe can be adjusted in software as disclosed in US Patent Publication No. 20150298153 to correct alignment errors (e.g., with correction of remaining reproducible errors with respect to the transducers associated with the gripper and / or printhead transport system, as already referenced). Printing then occurs, per numeral 493. After printing, the freshly printed substrate is unloaded for curing while the system prepares to receive a new substrate under robotic or human direction.

[0094] FIG. 5 depicts several different implementation layers, collectively designated by reference number 501. Each one of these layers represents a possible separate implementation of the techniques introduced herein. First, the techniques as introduced in this disclosure can take the form of instructions (e.g., executable instructions or software for controlling a computer or printer) stored on a non-transitory machine-readable medium, as represented by graphic 503. Second, by computer icon 505, these techniques can also optionally be implemented as part of a computer or network within a company that designs or manufactures components for sale or use in other products. Third, as illustrated using storage medium graphic 507, the techniques already introduced ... The data may take the form of stored printer control instructions that, when processed, will cause the printer to process one or more layers of the component, depending on the use of different ink volumes or locations that, per the above discussion, mitigate alignment errors. It is noted that the printer instructions may be transmitted directly to the printer, for example, via a LAN. In this regard, the storage medium graphic may represent (without being limited to) a RAM inside or accessible to a computer or printer, or a portable medium such as a flash drive. Fourth, as represented by the processing device icon 509, the techniques introduced above may be implemented as part of a processing apparatus or machine, or in the form of a printer within such an apparatus or machine. It is noted that the particular depiction of the processing device 509 represents one exemplary printer device, for example, as discussed in connection with FIG. 4B. The techniques introduced above may also be embodied as an assembly of manufactured components. For example, in FIG. 5, several such components are depicted in the form of an array 511 of semi-finished flat panel devices that will be separated and sold for incorporation into final consumer products. The depicted devices may have one or more emissive or encapsulating layers or other layers, for example, processed depending on the methods introduced above. The techniques introduced above can also be embodied in the form of end consumer products as referenced, for example in the form of a display screen for a portable digital device 513 (e.g., an electronic pad or a smartphone, etc.), a television display screen 515 (e.g., an OLED TV), a solar panel 517, or other types of devices.

[0095] Having thus discussed in detail the sources of positional error and associated remedies, the present disclosure will now turn to a discussion of more detailed embodiments of specific processing apparatus.

[0096] III. Specific Implementation Figures 6A-6E are used to discuss a specific printer implementation as applied to the manufacture of an OLED display or a solar panel. Depending on the product design, the printers seen in these figures can be used to deposit layers for many products on a substrate at once (e.g., many smartphone or other portable device displays, perhaps hundreds at a time, as conceptually represented by the individual arrayed products on substrate 411 from Figure 4A) or layers for a single product per substrate, such as the display screen of HDTV 415 or solar panel 417 from Figure 4A. Many other exemplary applications will be apparent to those skilled in the art.

[0097] More specifically, Figure 6A shows the printer 601 as having several components that operate to enable reliable placement of ink drops on specific locations on the substrate. Printing in the illustrated system requires relative motion between each printhead assembly and the substrate. This can be accomplished with a motion system, typically a gantry or split-axis system. Either the printhead assembly can move over a stationary substrate (gantry type) or both the printhead assembly and the substrate can move in the case of a split-axis configuration. In another embodiment, the printhead assembly can be substantially stationary while the substrate is moved along both the x and y axes relative to the printhead.

[0098] The printer comprises a printer support table 603 and a bridge 605. The printer support table 603 is used to transport substrates (such as substrate 609) using a planar floating support surface mounted by a frame 604, while the bridge 605 is used to transport several printheads and various support tools, e.g., optical inspection tools, curing devices, etc. As mentioned above, the bridge allows one or more printhead assemblies 611A and 611B to move back and forth along the bridge 605 along the "slow axis", while a gripper (e.g., a vacuum gripper, not seen in this figure) provides a "fast axis" for transporting the substrate (e.g., in what is referred to elsewhere herein as the "y" dimension (e.g., see dimension legend 602)). To accomplish printing, a printhead assembly (e.g., primary assembly 611A) would be positioned at a suitable position along the bridge, while the vacuum gripper moves the substrate in a generally linear fashion along the "y" dimension to provide a first scan or raster. The printhead assembly 611A or 611B is then typically moved along bridge 605 to a different position and stopped, and the vacuum gripper then moves the substrate 609 back in the opposite direction under the new printhead assembly position to provide the subsequent scan or raster, etc.

[0099] The printer support table 603 can have a porous medium that provides a planar floating support surface. The planar floating support surface includes an input zone, a print zone, and an output zone, designated using numerals 606-608, respectively. A substrate 609 is depicted in the input zone 606, ready to be printed. A combination of gas positive pressure and vacuum can be applied through an array of ports or using a distributed porous medium provided by the support table. Such a zone, having both pressure and vacuum control, can be effectively used to provide a fluid spring between the floating table surface and each substrate 609. A combination of positive pressure and vacuum control can provide a fluid spring with bidirectional stiffness. The gap that exists between the substrate 609 and the surface of the floating table can be referred to as the "fly height", and this height is adjusted by controlling the positive pressure and vacuum port conditions. In this manner, the z-axis height of the substrate can be carefully controlled in various portions of the printer support table, including, but not limited to, in the print zone 607. In some embodiments, mechanical retention techniques such as pins or frames can be used to limit the lateral translation of the substrate while it is supported by the gas cushion. Such retention techniques can include using spring-loaded structures, such as to reduce momentary forces incident on the side of the substrate while it is being retained. This can be beneficial because high force impacts between a laterally translating substrate and the retention means can potentially cause chipping or catastrophic failure of the substrate. In other areas of the printer support table, the fly height does not need to be controlled as precisely, for example, in the input or output zones 606 and 608. "Transition zones" between areas such as where the pressure-to-vacuum nozzle ratio gradually increases or decreases can be provided. In an illustrative example, there can be an essentially uniform height between the pressure-vacuum zone, the transition zone, and the pressure-only zone, such that within tolerances the three zones can essentially lie in one plane.The fly height of the substrate over the pressure-only zone elsewhere may be greater than the fly height of the substrate over the pressure-vacuum zone, such as to allow sufficient height so that the substrate does not collide with the printer support table in the pressure-only zone. In an illustrative example, the OLED panel substrate may have a fly height of about 150 microns (μ) to about 300μ above the pressure-only zone, and then about 30μ to about 50μ above the pressure-vacuum zone. In an illustrative example, one or more portions of the printer support table 603 or other processing equipment may include an air bearing assembly provided by NewWay Air Bearings (Aston, Pennsylvania, United States of America). Porous media, such as those having physical dimensions defined to occupy the entirety of the substrate 609, or a defined area of ​​the substrate, such as the display area or an area outside the display area, may be obtained from Nano TEM Co., Ltd. (Niigata, Japan), and the like. Such porous media may include pore sizes defined to provide a desired pressurized gas flow over a defined area while reducing or eliminating mura or other visible defect formation.

[0100] In the embodiment of FIG. 6A, a handler or other transport system (not shown) transports each substrate 609 to the input area 606 of the printer support table 603. The vacuum gripper engages the substrate 609 and transports it from the input zone 606 into the print zone 607, then moves the substrate back and forth for printing, achieving a separate "near frictionless", low particle generating high speed scan along the fast axis of the printer according to a specific recipe. When printing is finished, the vacuum gripper then transports the substrate to the output zone 608, where a mechanical handler takes over and transports the substrate to the next processing device. During this time, a new substrate can be received in the input zone 606, and the vacuum gripper is then transported back to that zone to engage the new substrate. In one embodiment, the deposited droplets of ink are allowed to mix together in the output zone, e.g., via a short rest or fixing cycle in which the substrate is allowed to remain in the output zone, and the printing and fixing and subsequent curing are performed in a controlled environment (e.g., generally in a nitrogen or noble gas atmosphere or other non-reactive environment).

[0101] The depicted printer 601 may also include one or more maintenance or administration bays 612A and 612B, each of which may store tools 615-620, e.g., printheads, cameras, "ink sticks," for modular engagement with one or both printhead assemblies. Similarly, in one embodiment, these bays are configured for interaction with other components, such as a drop measurement module, a purge basin module, a blotter module, and the like, optionally within the same enclosure volume or a second volume. In one embodiment, the printhead assembly can simultaneously load three "ink sticks," as represented by numeral 622, with each "ink stick" supporting three printheads and supporting fluid and circuit contacts in a manner adapted for modular engagement with the printhead assembly. The ink delivery system (not shown separately in FIG. 6A) includes one or more ink reservoirs, ink supply tubing which carries ink between the reservoirs and one or more of the printhead assemblies, and suitable control circuitry, while the motion system (also not shown separately in FIG. 6A) includes electronic control elements such as a subsystem master processor and control system, actuation elements for the gripper and printhead assemblies, and suitable control code.

[0102] Each printhead assembly 611A / 611B includes a traveler 623A / 623B that rides along the bridge (i.e., on a track or guide) and an engagement mechanism 624A / 624B mounted adjacent a front face 625A / 625B of the bridge for robotically engaging and disengaging ink sticks or other tools, as desired, on a modular basis, with respective support bays 612A / 612B. Each printhead assembly (611A / 611B) is supported by a linear air bearing motion system (essentially low particle generation) or other linear motion system to enable it to move along the bridge 605. Each printhead assembly is accompanied by fluidic and electronic connections to at least one printhead, each printhead having hundreds to thousands of nozzles capable of ejecting ink at a controlled rate, velocity, and size. Providing one illustrative example, the printhead assembly can include about 1 to about 60 printhead devices, each of which can have about 1 to 90 printheads, each of which can have 16 to about 2,048 nozzles, each of which can emit droplets having a volume of about 1 to 20 picoliters (pL), depending on the design. Each of the front faces 625A / 625B provides a separate z-axis movement plate that controls the elevation of the engagement mechanism (and thus the printhead or other tool) above the surface of the substrate. The traveler and engagement mechanism can serve as the "first" and "second" components already referenced with respect to the printhead assembly, for example, these components are coupled by an electromechanical interface (not seen in FIG. 6A) that allows for robotic adjustment of the transported tool in each of the x, y, and z dimensions, in one embodiment. In this regard, the already referenced U.S. Provisional Patent Application No. 62 / 459,402 generally provides details regarding the z-axis calibration of the printhead and various other elements of the printer's coordinate reference system.The electromechanical interface may advantageously include stepper motors, fine adjustment screws, and other mechanisms for adjusting (a) the x, y, and / or z mounting of each tool relative to an associated engagement feature, and (b) the pitch between individual tools (e.g., pitch between ink sticks). In addition, each tool may also include various fine adjustment mechanisms, for example, for pitch adjustment between multiple printheads carried by each ink stick. The electromechanical interface may optionally include kinematic or similar mounts for repeatably and reliably engaging each tool to within 1 micron of its intended position in each dimension, along with robotic adjustment mechanisms configured to provide feedback for precise position adjustment of each tool relative to the engagement features.

[0103] The electromechanical interface also advantageously includes a set of transducers as already referenced, e.g., to offset the engagement features 624A / 624B linearly in the "y" dimension relative to the associated traveler 623A / 623B. As should be apparent from the discussion thus far, the provision of a transducer correction feature that provides a "virtual straight edge" for the printhead and another "virtual straight edge" for the gripper (not seen in FIG. 6A ) promotes a printing grid that is more "regular", e.g., helps to ensure uniform drop placement at the precise regular intervals associated with the printing grid, thereby promoting layer uniformity.

[0104] As should be apparent, the depicted structural elements allow control over substrate x-axis position using common mode displacement of the substrate by a separate voice coil assembly, and control over substrate orientation about the θ dimension (i.e., rotation about the z-axis). Various embodiments of the depicted gripper system can maintain substrate orientation parallel to the y-axis of travel within + / - 4,300 microradians or less, depending on implementation. As previously mentioned, when it is also desired to adjust the substrate position to more closely match deviations in the printhead (printhead assembly) position and orientation, this control over orientation along with common mode x-axis displacement, and the effective implementation of a floating pivot point for the substrate, allows precise repositioning of the substrate, simulating a perfect virtual edge (or guide) for each substrate and traveler motion (e.g., printhead, camera, etc.). As previously mentioned, the vacuum gripper and printhead assembly / traveler each also include an optical system (not seen in the figures) for detecting registration marks, i.e., providing electronic position signals precisely indicating the location of the gripper or printhead assembly along the associated transport path.

[0105] As should be observed, the use of the voice coil in combination with the air (gas) bearing support of the substrate and the vacuum-based engagement between the gripper and the substrate provides an efficient mechanism for frictionless and effective mechanism for both substrate transport and fine position adjustment. The present structure helps to maintain minimal contact interaction with the substrate during electronic component processing (e.g., during layer deposition and / or curing), which helps to avoid distortions and defects that may otherwise occur as a result of substrate deformation, contact-induced local substrate temperature variations, or other effects such as electrostatic energy accumulation. At the same time, the nearly frictionless support and transducer system, in combination, helps to provide a micron-scale or better throw used to perform fine adjustments of the substrate position. These structures help to perform the precise substrate corrections necessary to obtain one or more "virtual transport paths" despite mechanical imperfections as already referenced, and despite the fact that the substrates serving as deposition targets may be meters long and meters wide. The voice coil can also be configured to provide a relatively large maximum throw, for example 7 microns or more, which may be significant depending on the implementation (e.g., when the system in question is subject to jitter of this magnitude, given its manufacturing tolerances).

[0106] 6B shows the vacuum gripper 631 in additional detail. The vacuum gripper 631 again comprises a first component 633 (riding on a y-axis carriage, not seen in the figure), a second component 635 that engages the substrate, and two linear transducers 637 and 639. As depicted, it should be noted that the second component is positioned vertically above the first component as both are advanced along the gripper's transport direction (e.g., along the "y dimension" depicted by legend 632), and the second component supports a vacuum chuck 643 that is used to selectively engage the substrate. Unlike the previous example, which assumes the use of a virtual pivot point, this example further includes a floating mechanical pivot assembly or mechanism 641 that provides a mechanical linkage between the first and second components 633 / 635 as the gripper is advanced along the y dimension, and helps provide structural support for embodiments in which the linear transducers are embodied as voice coils. The floating pivot mechanism includes a pivot shaft 651, an assembly top plate 653 (mounted to the gripper second component 635), and an x-axis sliding bottom plate 655 that moves on rails relative to a support frame 644 provided by the gripper first component 633. The assembly top plate is preferably made of a relatively thin material to provide flexure and allow, for example, leveling of the gripper second component relative to the substrate and floating table, and is rigidly fixed to the second gripper second component using a mounting bracket 656. Briefly, as component 633 is advanced along the y dimension, the floating mechanical pivot mechanism 641 constrains component 635 to similarly advance along the y dimension while allowing x-axis sliding interaction between these components 633 / 635 and rotation about the floating pivot axis 649.

[0107] The floating pivot point allows for differential or common mode drive of the transducers 637 and 639 as discussed above. These various motions are further represented by a set of motion arrows 645 / 647. Generally speaking, each transducer couples a mounting block 657 (e.g., mounted to a frame 644 of the first component of the gripper) and a mounting plate 661 (mounted to the second component of the gripper), and a linear actuator 659 couples the mounting block and mounting plate to provide precision displacement along the x-axis. Number 662 identifies a linear encoder that generates a signal for each nanometer displacement of the associated transducer, i.e., provides feedback to drive the precision displacement value. As represented by dashed outlines 663 and 665, the design of the transducers 637 / 639 and the floating mechanical pivot mechanism 641 will be shown and discussed in further detail in connection with Figures 6C and 6D.

[0108] Of note, FIG. 6B also shows mechanical banker 658, which provides a “stop” for coarse mechanical alignment of each introduced substrate, and an “up-looking” camera 667, which is used to image fiducials via optical path 669 (represented in the figure as a focal cone) and to identify the relative distances and positions of various printhead assembly components (e.g., fine printhead nozzle positions and printhead assembly camera, not shown, in terms of the printer's coordinate reference system) for purposes of aligning the vacuum gripper and printhead assembly (not shown) to define the printer's coordinate reference system.

[0109] Figure 6C shows a close-up view of the linear transducer 637 from Figure 6B. Again, the other transducer (designated by numeral 639 in Figure 6B) is substantially identical or symmetrical in design to transducer 637.

[0110] More specifically, the linear transducer assumes a voice coil design in this embodiment with the gripper first and second components 633 / 635 supported on air bearings. The voice coil is contained within a cylindrical housing 659 to allow displacement of the first component (e.g., vacuum chuck bar and substrate) relative to the second component along the general direction of double arrow 645. Adjustment plate 670 advantageously allows fine adjustment of the transducer xyz orientation as between these two components to linearly move the second component along the x-dimension axis (see dimension legend 632 in FIG. 6B). Again, this can be provided with a manually adjustable screw arrangement that is adjusted and / or calibrated at low frequency. The voice coil again has a magnet-based design that provides a fast, precise microscopic throw and displaces mounting plate 661 in response to an electronic control signal, i.e., toward and away from mounting block 657, again in the direction of double arrow 645.

[0111] FIG. 6D shows the floating mechanical pivot mechanism 641 from FIG. 6B. As previously described, the assembly top plate 653 carries a bushing that allows pivoting of the assembly top plate (and gripper second component and vacuum chuck) about the pivot axis 649. This axis is defined by a pivot shaft 651 that extends vertically downward parallel to the z dimension and couples to an x-axis sliding lower plate 655. Although not seen in the figure, the x-axis sliding lower plate 655 is generally coupled to the gripper first component by rails (via the support frame 644) to allow relatively frictionless x-axis displacement of the assembly top plate 653, pivot shaft 651, vacuum chuck 643, and gripper second component 635 relative to the component 633 (and support frame 644), while simultaneously constraining these two components 633 / 635 to move together in the y dimension. This structure provides mechanical support for the floating pivot point, and common and differential mode voice coil displacements are used to provide error mitigation offsets of the second component along the directions of arrow 673 and rotational arrow 675, respectively. Note that the floating pivot point is not required for all embodiments, for example, in embodiments where the transducers provide sufficient output impedance, the mechanical pivot mechanism could potentially be omitted. Regardless of whether a mechanical support structure is used, the floating pivot point advantageously enables common and differential mode control for multiple transducers to reposition the substrate in the x and θ dimensions, thus approximating the ideal transport path of a "straight edge". Various modifications and equivalents will no doubt occur to those skilled in the art.

[0112] FIG. 6E provides a schematic diagram 681 illustrating elements of the pivot mechanism represented by FIGS. 6B-6D. More specifically, this figure now illustrates linear x-axis rails 683 that effectively provide bearings 685 on either side of the x-axis sliding lower plate 655, allowing the structure (and all that is supported above it) to ride in and out of the drawing page. At the same time, the assembly top plate 653 mounts a bushing 686 to allow free rotation of that plate relative to the x-axis sliding lower plate 655 about the pivot axis 649. More specifically, the bushing 686 supports the bearings 689 and enables this rotation. FIG. 6E also illustrates the flexure provided by the assembly top plate 653 relative to the gripper second component 635 and transducers 637 / 639.

[0113] Although the transducer correction mechanism depicted in Figures 6A-6D is illustrated in the context of a gripper assembly, the same basic structure can also be used for the printhead assembly (or for each printhead assembly or other tool carrier). Specifically, a first component rides on a track (or x-axis carriage assembly) on gas bearings, while a second component carrying the printhead (or other tool) is displaced in the "y" and / or "z" dimensions depending on the position error in that dimension depending on the x-axis position (and / or other factors, e.g., temperature). For correction in a given dimension, two transducers are again used in conjunction with a virtual or floating pivot point to achieve both y and θ corrections (or z and xz plane angle corrections) in the relative position of the printhead to the substrate, and in doing so, force the printhead to follow a virtual straight edge path. Optionally, the two transducers Such correction mechanisms can be used together to provide straight edge paths for each gripper and printhead transport system, respectively, to effectively provide a very precise regular print grid that provides further accuracy over droplet placement. The Z-axis adjustment of the printhead can also be controlled using a similarly designed transducer-based motion correction system to provide altitude correction of the printhead orifice plate relative to the substrate surface, thereby managing altitude differences and also with improved accuracy. Other degrees of freedom can also be corrected in this manner. In precision motion systems, particularly printer-based processing systems where the coordinate reference system used for printing / manufacturing is effectively related to multiple transport paths, the use of multiple correction systems of this type improves accuracy over droplet landing locations, thus promoting further uniformity in the processed layers. This in turn makes it easier to produce thinner layers, for example, having a thickness of 5 microns or less. Again, it should be noted that while the designs discussed above emphasize the use of "virtual straight edges" for the purposes of improving the regularity of the printing grid, not all embodiments are so limited, and nearly any desired "ideal" path may be approximated using the teachings provided herein.

[0114] IV. Error measurement It should be noted that in systems that correct for repeatable motion errors, it is generally desirable to measure the errors precisely to ensure reliable operation. This can be performed for the gripper transport system, the print head transport system, and / or another transport system, as appropriate, using manual and automated error measurement processes. The manual process is described first below, followed by the less cumbersome automated measurement process.

[0115] In a first technique, a high resolution camera can be used to precisely identify the position and / or orientation of what is being transported in relation to progress along the transport path, optionally at each forward movement point along the transport path, optionally using a subset of these forward movement points and interpolation to identify an error model for the transport path.

[0116] For example, as alluded to above, in one embodiment, this calibration / error measurement can be performed with respect to the gripper transport system by introducing a test substrate, aligning it to the gripper (e.g., using the high-resolution imaging process and substrate fiducials as described above), and advancing the substrate according to a desired printing recipe. However, instead of printing according to the corresponding printing recipe, a high-resolution camera is transported in both x and y (incrementally between transport path advances) and used to find the specific position of one or more of the substrate's fiducials in terms of the printer's coordinate reference system. Search algorithms and image processing can be used to find the precise position, which then allows processor derivation of the deviation from the expected coordinates. This error calculation (and calculation of the mitigated transducer drive signal) can be performed by a calibration subsystem (i.e., separate from the gripper servo control subsystem, with the error / transducer mitigation then forwarded to the gripper servo control subsystem), or the calibration process can be directly built into the gripper servo control system. In another possible implementation, it is also possible to print over the entire substrate and then use forensics (e.g., latent image processing) to identify jitter / corrections, relying on analyzing the printer drop deposition pattern. Image processing is used to identify drop landing locations and / or parameters of the deposited wet or cured film, and infer jitter and mitigation corrections from the identified locations / parameters. In yet another possible process, a CCD or line scanner can be used to continuously analyze recognizable features on the substrate during deposition, and to infer jitter from translational and angular deviations in x and θ as the substrate is dynamically advanced. In an almost identical manner, the transported printhead can also be used to measure the jitter and mitigation corrections of the printhead. The printheads may also be analyzed, for example, using an "up-looking" camera to periodically identify fiducials on the printhead assembly (possibly including individual nozzle positions) and to identify y and / or z positional deviations of the printheads and changes in the levelness of each printhead orifice plate. For example, a separate camera system can be used to image the printheads at different positions along the printhead transport dimension to identify minor positional and / or angular deviations.

[0117] 7A shows the automated error measurement process, again applied to a gripper transport system. Again, it is noted that the same process can also be used to measure the printhead position (e.g., by mounting interference optics on the printhead assembly as it is transported and detecting minute position and angular deviations of the printhead assembly along its path of advancement).

[0118] 7A provides an illustrative diagram used to depict how substrate (or gripper) position errors are measured. The measurement system is generally represented by the numeral 701 and relies on the use of laser interferometry to measure positional deviations (in this example) in each of the x and y dimensions and substrate rotation (yaw, represented elsewhere herein by the variable θ). More specifically, a test substrate 703 is held by a vacuum chuck 705 (e.g., carried by the "second component" of the gripper as already referenced), which has interferometry optics 707 mounted thereon. The substrate has alignment marks, as introduced above, and the gripper also has one or more alignment marks that are located and imaged by a camera or other imaging system during initial substrate introduction, in order to precisely position the substrate relative to the vacuum chuck. In one embodiment, a mechanical handler or motorized bunker is used to reposition the substrate until the proper relative position is achieved, while in a second embodiment, the error compensation system introduced above (e.g., two or more transducers and a floating pivot point) is used to reposition the substrate and have the proper orientation, and the corresponding transducer position is taken as the "zeroed" or initialized position of the error correction system. The substrate and vacuum chuck are then moved along the gripper transport path, as represented by numeral 727, as would ideally be implemented as part of the desired printing recipe. During this time, a laser 709 emits light of a specific wavelength that travels through the gripper-mounted optics 707, is directed along one or more paths 727 to a mirror / target 713, and then bounces back through the optics assembly to a detector 711 via path 729. The nature of the target is such that if the substrate undergoes jitter or deviation along the dimension being measured (e.g. translation or orientation variation), this creates a diffraction pattern which is sensed by detector 711, fed to computer 719 and used to generate values ​​which are used to calculate a precise error / position value depending on the gripper position or advancement.It should be noted that the laser interferometry system (laser source 709, detector 711, and target 713) is mounted in a fixed manner to the printer chassis 717, while movement of the optics 707 relative to the laser 709 and target 713 generates an interference pattern that is measured for error. Through suitable configuration of the optics, any of the x, y, theta, or other dimensional errors can be dynamically measured as the substrate is advanced. It should be noted that other errors (e.g., z-axis or other angular deviations) can also be measured depending on how the optics are configured and the number of detectors and / or light sources used. It should be noted that laser interferometry measurement systems are currently used in certain machine tools, and it would be within the level of one skilled in the art to configure the laser source and / or target using known techniques to measure each dimension of interest. For example, a suitable interferometry system is the "XL-80" laser system available from Renishaw, PLC, which also publishes training materials on optical positioning and fine position measurement. It would be within the level of one skilled in the art to adapt these materials to measurements of substrate and / or gripper position. After measurement, error calculation / compensation is then performed by a computer (i.e., by one or more processors acting under the control of suitable software 721). As mentioned above, the errors and / or corrections 731 can be stored in a non-transient memory device 723 (e.g., a look-up table) for subsequent retrieval during a production run in a manner indexed by gripper position and / or other factors (e.g., temperature, specific recipe, specific panel, etc.).

[0119] FIG. 7B is similar to FIG. 7A, but shows a configuration 741 for measuring minute mechanical defects that produce errors in printhead position or camera position in a printing system. As before, a computer 719, software 721, and non-transient storage 723 are used to measure the errors. In FIG. 7B, a printhead assembly (or other transported object) is represented by numeral 745, and interferometry optics are mounted to this assembly as represented by numeral 743. The assembly moves back and forth along a traveler 747 as indicated by numeral 755, and a laser source 749, target 751, and detector 753 are again used to measure position deviations along the dimension being measured. As before, the laser source 749, target 751, and detector 753 are all precisely mounted to the chassis 717 and do not move during measurement. As FIG. 7B illustrates, any mechanical transport path can be measured in this manner, and such paths may be independent of the substrate or other transport path (on which the correction transducer is mounted). Again, the stored error and / or correction values ​​757 can then be retrieved from non-transient storage (e.g., a look-up table) as needed during the processing run, indexed as needed by print head / camera position and / or other factors (e.g., temperature, specific recipe, specific panel, etc.).

[0120] As already referenced, it may be necessary to identify where the camera and / or print head are relative to the gripper (not seen in FIG. 7B). As mentioned above, each transport system has one or more registration marks, so that the assembly 745 can be moved to a specific location (e.g., "position zero" to the left of the traveler 747) simultaneously with the advancement of the gripper to its "position zero", and a search process and camera imaging is used to identify the coordinate system "origin", as already referenced. Similarly, a test substrate with registration marks (and known geometry) can then be introduced to measure and correlate the coordinate systems with respect to the gripper (and floating table) so that their positional relationships are precisely known. This type of processing is also advantageously performed by a computer and / or processor 719 acting under the control of suitable software 721.

[0121] The automated error measurement process offers many advantages, including that testing steps can be performed during the calibration process, and errors and / or corrections are dynamically recorded during continuous operation of each transport system. The recorded errors and / or corrections can then be played back as described. If desired, the error measurement process can be re-performed, for example, at system start-up, upon milestone events (e.g., printhead changes, when pre-determined error thresholds are met, or at periodic intervals), or upon request (or operator command) to update or replace previously identified error and / or correction values.

[0122] V. Conclusion Considering the various techniques and considerations introduced above, manufacturing processes can be implemented to mass-produce products quickly at low per-unit costs. When applied to display device or solar panel manufacturing, e.g., flat panel displays, these techniques optionally enable high speed panel-by-panel printing processes, where multiple panels are produced from a common substrate. By providing high speed, repeatable printing techniques (e.g., using common inks and printheads per panel), printing is substantially improved. It is believed that the present invention can be applied to a wide variety of applications, for example reducing the printing time per layer to a small fraction of the time that would be required without the above techniques, while ensuring consistent precision deposition of ink all within the desired target area of ​​each substrate. Returning again to the example of a large HD television display, it is believed that each color component layer can be accurately and reliably printed for large substrates (e.g., 8.5 generation substrates that are approximately 220 cm x 250 cm) in 180 seconds or less, or even 90 seconds or less, which represents a substantial process improvement. By improving the efficiency and quality of printing, it paves the way for a significant reduction in the cost of producing large HD television displays, and thus lower end consumer costs. As previously mentioned, display manufacturing (specifically, OLED manufacturing) is one application of the techniques introduced herein, but these techniques can be applied to a wide variety of processes, computers, printers, software, manufacturing equipment, and end devices, and are not limited to display panels. In particular, it is anticipated that the disclosed techniques can be applied to any process where a printer is used to deposit multiple product layers as part of a common printing operation, including, but not limited to, many microelectronic applications.

[0123] It is noted that the described technique offers a number of options. In one embodiment, panel (or product-by-product) misalignment or skew can be adjusted on a product-by-product basis within a single array or on a single substrate. The printer scan path can be planned so that misorientation of the substrate (or other transported item such as a print head) is automatically compensated for via transducers coupling the substrate and the transport system (e.g., grippers) without the need for adjustment / adaptation based on one or more alignment errors. In one embodiment, transducer corrections can be used to mitigate errors in different transport paths (e.g., print head transport paths). Optionally, such corrections can be based on pre-measured errors that are expected to repeat from substrate to substrate (or panel to panel).

[0124] Also, while various embodiments illustrate the use of a gripper (or mechanism coupling the substrate to a transport mechanism) and the use of two transducers to achieve fine adjustment, other embodiments may use a different number of these elements. For example, in one embodiment, two or more grippers, each with their own dedicated transducer, may be used. Alternatively, it is possible to use more than two transducers and / or transducers for more than two correction axes. In addition, while the techniques described above are illustrated as applied to a printer using a vacuum gripper system, many other applications may benefit from the techniques described, including applications using a different type of transport mechanism, a different type of printer, a different type of deposition mechanism, or another type of transport path or mechanism. Clearly, many variations exist without departing from the inventive principles described herein.

[0125] In the foregoing description and accompanying drawings, specific terms and drawing symbols have been set forth to provide a thorough understanding of the disclosed embodiments. In some cases, the terms and symbols may imply specific details that are not required to practice these embodiments. The terms "exemplary" and "embodiment" are used to express examples rather than preferences or requirements.

[0126] As shown, various modifications and changes may be made to the embodiments presented herein without departing from the broader spirit and scope of the present disclosure. For example, a feature or aspect of any of the embodiments may be applied in combination with any other of the embodiments, or in place of its corresponding feature or aspect, at least where practical. Thus, for example, not all features are shown in each and every drawing, and it is assumed that, for example, a feature or technique shown according to an embodiment of one drawing can be adopted as an element of or in combination with a feature of any other drawing or embodiment, even if not specifically declared in this specification. Thus, the present specification and drawings are to be regarded in an illustrative sense, not a restrictive sense. (Item 1) 1. An apparatus for processing a layer of an electronic product, comprising: a printer for depositing material onto a substrate, said material forming said layer; and a transport system for transporting the substrate during deposition of the material; at least one of the printer or the transport system having a component advanced along a transport path, the advancement of the component being characterized by mechanical imperfections that generate at least one of a translation error and a rotation error that affects deposition of the material on the substrate; at least one transducer operatively coupling the transport path and the substrate, the at least one transducer being actuated in response to the at least one error to offset the substrate relative to an advancement of the component to compensate for the mechanical imperfection; An apparatus comprising: (Item 2) 2. The apparatus of claim 1, wherein the component comprises a gripper for the substrate, and the mechanical defect comprises a defect in at least one of the transport system or the substrate. (Item 3) 2. The apparatus of claim 1, wherein the transport system comprises a floating table that supports the substrate on gas bearings, and a gripper that operatively engages the substrate and transports the substrate along the transport path relative to the floating table. (Item 4) 4. The apparatus of claim 3, wherein each transducer of the at least one transducer comprises one of a voice coil, a linear motor, or a piezoelectric transducer. (Item 5) the conveying system is a first conveying system and the component is a first component; the printer includes a second transport system for transporting the printhead along the printhead path; At least one of the printer or the second transport system further comprises a second component advanced along the print head path, the advancement of the second component being characterized by mechanical imperfections that generate at least one of a translation error and a rotation error that affects deposition of the material on the substrate; 2. The apparatus of claim 1, comprising at least one transducer operatively coupling the print head path and the print head, the transducer being driven in response to the at least one error characterizing the advancement of the second component. (Item 6) 6. The apparatus of claim 5, wherein the print head is constrained by the transport system to move along the print head path in a direction perpendicular to a direction of transport of the substrate, and the print head is repositioned along the print head path between successive scans of relative motion actuated by the first transport system. (Item 7) 7. The apparatus of claim 6, wherein the first transport system comprises a gas bearing and a vacuum gripper that operably engages the substrate, the second transport system comprises a gas bearing, and each transducer comprises a voice coil. (Item 8) The conveying system is a first conveying system, and the component is a first component. can be, the printer includes a second transport system for transporting the camera along a camera path; At least one of the printer or the second transport system further comprises a second component advanced along the camera path, the advancement of the second component being characterized by mechanical imperfections that generate at least one of a translation error and a rotation error; 2. The apparatus of claim 1, further comprising at least one transducer operatively coupling the camera path and the camera, the transducer being driven in response to the at least one error characterizing the advancement of the second component. (Item 9) The apparatus comprises an enclosure that contains a controlled atmosphere; the printer being an inkjet printer within the enclosure; the transport system comprising a floating table supporting the substrate on gas bearings, and a gripper operatively engaging the substrate and transporting the substrate along the transport path while supported by the gas bearings; 2. The apparatus of claim 1, wherein the mechanical defect comprises a defect in at least one of the conveying system and the substrate. (Item 10) 10. The apparatus of claim 9, wherein each transducer of the at least one transducer linearly displaces the substrate in a dimension orthogonal to the transport path. (Item 11) Item 1, the at least one transducer comprises at least two transducers, the apparatus further controls the at least two transducers according to each of a common mode control, in which the at least two transducers are driven to linearly displace the substrate relative to the transport path in a direction perpendicular to the transport path, and a differential mode control, in which the at least two transducers are driven to rotate the substrate relative to the transport path, the apparatus further comprises a mechanical assembly coupling the transport path and the substrate, the mechanical assembly providing a floating pivot for the component to pivot relative to the transport path. (Item 12) Item 12. The apparatus of item 11, comprising means for recording at least one of the error or transducer drive information indexed as a function of substrate advancement along the transport path. (Item 13) 1. An apparatus for processing a layer of an electronic product, comprising: an enclosure for a controlled atmosphere; an inkjet printer within said enclosure for depositing a material onto a substrate, said material forming said layer; a transport system for transporting the substrate during deposition of the material; at least one of the printer or the transport system having a component advanced along a transport path within the enclosure, the advancement of the component being characterized by mechanical imperfections that generate at least one of translational and rotational errors that affect deposition of the material on the substrate; two or more transducers operatively coupled to the transport path and the substrate, the two or more transducers being driven in response to the at least one error to offset the substrate relative to an advancement of the component to compensate for the mechanical imperfections, the two or more transducers each achieving a respective throw to displace the substrate in a direction perpendicular to the transport path; An apparatus comprising: (Item 14) Item 14. The apparatus of item 13, wherein the transport system comprises a floating table that supports the substrate on gas bearings, and a gripper that operatively engages the substrate and transports the substrate along the first transport path relative to the floating table, and each transducer of the two or more transducers comprises a voice coil. (Item 15) Item 15. The apparatus of item 14, comprising means for recording at least one of the error or transducer drive information indexed as a function of substrate advancement along the transport path. (Item 16) The inkjet printer includes a traveler and a printhead that travels along a second transport path; the second transportation path is characterized by mechanical imperfections that generate a second error, the second error comprising at least one of a translation error and a rotation error; Item 14. The apparatus of item 13, further comprising two or more second transducers, the two or more second transducers being driven in response to the second error so as to compensate for the mechanical imperfections characterizing the second transport path, and the two or more second transducers each achieving a throw that displaces the print head in a direction perpendicular to the second transport path. (Item 17) Item 14. The apparatus according to item 13, further comprising: a common mode control, in which the two or more transducers are driven to linearly displace the substrate relative to the transport path in a direction perpendicular to the transport path; and a differential mode control, in which the two or more transducers are driven to rotate the substrate relative to the transport path; and further comprising a mechanical assembly coupling the transport path and the substrate, the mechanical assembly providing a floating pivot for the component to pivot relative to the transport path. (Item 18) 1. A method for processing a layer of an electronic product, comprising: depositing a material onto a substrate using a printer, said material forming said layer; transporting the substrate during deposition of the material using a transport system, where at least one of the printer or the transport system has a component that is advanced along a transport path, the advancement of the component being characterized by mechanical imperfections that generate at least one of a translational error and a rotational error that affects deposition of the material on the substrate; driving at least one transducer operatively coupling the transport path and the substrate in response to the at least one error to offset the substrate relative to advancement of the component to compensate for the mechanical imperfection; A method comprising: (Item 19) 20. The method of claim 18, wherein the transport system comprises a floating table that supports the substrate on gas bearings, and a gripper that operatively engages the substrate and transports the substrate along the transport path relative to the floating table. (Item 20) 20. The method of claim 18, wherein each transducer of the at least one transducer comprises one of a voice coil, a linear motor, or a piezoelectric transducer. (Item 21) the conveying system is a first conveying system and the component is a first component; The method further includes transporting the print head along the print head path using a second transport system; At least one of the printer or the second transport system further comprises a second component advanced along the print head path, the advancement of the second component being characterized by mechanical imperfections that generate at least one of a translation error and a rotation error that affects deposition of the material on the substrate; 20. The method of claim 18, further comprising driving at least one transducer operatively coupling the print head path and the print head in response to the at least one error characterizing advancement of the second component. (Item 22) 22. The method of claim 21, wherein the print head is constrained by the transport system to move along the print head path in a direction perpendicular to a direction of transport of the substrate, and the print head is repositioned along the print head path between successive scans of relative motion actuated by the first transport system. (Item 23) 23. The method of claim 22, wherein the first transport system comprises a gas bearing and a vacuum gripper that operably engages the substrate, the second transport system comprises a gas bearing, and each transducer comprises a voice coil. (Item 24) the conveying system is a first conveying system and the component is a first component; The method further includes transporting the camera along a camera path using a second transportation system; At least one of the printer or the second transport system further comprises a second component advanced along the camera path, the advancement of the second component being characterized by mechanical imperfections that generate at least one of a translation error and a rotation error; 20. The method of claim 18, further comprising driving at least one transducer operatively coupling the camera path and the camera in response to the at least one error characterizing an advancement of the second component. (Item 25) The printer is an inkjet printer, depositing the material includes operating the inkjet printer and the material in the controlled atmosphere; the transport system comprises a floating table supporting the substrate on gas bearings, the method further comprising engaging the substrate with a gripper and transporting the substrate along the transport path while supported by the gas bearings; 20. The method of claim 18, wherein the mechanical defect comprises a defect in at least one of the transportation system and the substrate. (Item 26) 26. The method of claim 25, wherein each transducer of the at least one transducer linearly displaces the substrate in a dimension orthogonal to the transport path. (Item 27) 19. The method of claim 18, wherein the at least one converter comprises at least two converters, the method further comprising controlling the at least two converters according to each of a common mode control, in which the at least two converters are driven to linearly displace the substrate relative to the transport path in a direction perpendicular to the transport path, and a differential mode control, in which the at least two converters are driven to rotate the substrate relative to the transport path, and the method further comprises providing a floating pivot for pivoting the component relative to the transport path. (Item 28) 28. The method of claim 27, further comprising recording at least one of the error or transducer drive information indexed as a function of substrate advancement along the transport path.

Claims

1. A printing device, comprising: a printhead assembly having a track, a first member movably disposed on the track, a second member coupled to the first member via a linear transducer, and a printhead coupled to the second member; The linear transducer moves the second member and the printhead relative to the first member in a direction perpendicular to the track by a distance that corresponds to a position or rotation error of the printhead.

2. A printing device as described in claim 1, wherein the linear converter is a first linear converter and further comprises a second linear converter connecting the first member to the second member, and the second linear converter also moves the second member and the print head relative to the first member in a direction perpendicular to the track by a distance corresponding to an error in the position or rotation of the print head.

3. A printing device as described in claim 2, wherein the first and second linear converters move the print head in a direction perpendicular to the track in a common mode and rotate the print head in a differential mode.

4. A printing device as described in claim 2, wherein each of the first and second linear converters includes either a voice coil, a linear motor, or a piezoelectric converter.

5. The printing apparatus of claim 1, wherein the linear converter is a first linear converter, and further comprising a conveying system for transporting the substrate during deposition of material from the print head onto the substrate; A printing apparatus, wherein the conveying system comprises: a first member coupled to a transport path; and a second member coupled to the first member via a second linear transducer, the second member moving the substrate and the second member relative to the first member in a direction perpendicular to the transport path by a distance corresponding to a position or rotation error of the substrate.

6. A printing device as described in claim 1, wherein the first member is supported on the track by a gas bearing.

7. A printing apparatus as described in any one of claims 1 to 6, further comprising a floating table that supports the substrate while material is deposited from the print head onto the substrate.

8. A printing device as described in claim 1, further comprising a pivot mechanism connecting the first member and the second member.

9. A printing device as described in claim 5, further comprising a pivot mechanism connecting the first member and the second member, the pivot mechanism being positioned between the first and second linear converters.

10. A printing device as described in claim 1, further comprising means for recording at least one of the position or rotation error of the print head or the information of the linear converter according to the position of the print head along the track.

11. A printing device, comprising: an enclosure for a controlled atmosphere; an inkjet printer disposed within the enclosure; The inkjet printer comprises a printhead assembly including a track, a first member movably disposed on the track, a second member coupled to the first member via a linear converter, and a printhead coupled to the second member; The linear transducer moves the second member and the printhead relative to the first member in a direction perpendicular to the track by a distance that corresponds to a position or rotation error of the printhead.

12. A printing apparatus as described in claim 11, wherein the inkjet printer further comprises a floating table that supports the substrate while depositing material from the print head onto the substrate.

13. A printing apparatus as described in claim 11, further comprising means for recording at least one of a position or rotation error of the print head or information from the linear converter as a function of the position of the print head along the track.

14. A printing device as described in claim 11, wherein the linear converter comprises one of a voice coil, a linear motor, or a piezoelectric converter.

15. The printing apparatus of claim 11, wherein the linear converter is a first linear converter, and further comprising a conveying system for transporting the substrate during deposition of material from the print head onto the substrate; a second member coupled to the first member via a second linear transducer, the second member moving the substrate and the second member relative to the first member in a direction perpendicular to the transport path by a distance corresponding to a position or rotation error of the substrate; 16. A printing apparatus as described in claim 15, wherein the inkjet printer further comprises a floating table that supports the substrate while depositing material from the print head onto the substrate.

17. A printing device as described in claim 15, further comprising a pivot mechanism connecting the first member and the second member, the pivot mechanism being positioned between the first and second linear converters.

18. A printing device, comprising: an enclosure for a controlled atmosphere; a floating table for supporting the substrate; an inkjet printer disposed within the enclosure; The inkjet printer includes a printhead assembly including a track, a first member movably disposed on the track, a second member coupled to the first member via a linear converter, and a printhead coupled to the second member, wherein the track positions the printhead to deposit material onto a substrate, and the linear converter moves the printhead and the second member relative to the first member in a direction perpendicular to the track by a distance corresponding to a position or rotation error of the printhead.

19. The printing apparatus of claim 18, wherein the linear converter is a first linear converter, and further comprising a transport system for transporting a substrate supported by the floating table during deposition of material; A printing apparatus, wherein the conveying system comprises: a first member coupled to a transport path; and a second member coupled to the first member via a second linear transducer, the second member moving the substrate and the second member relative to the first member in a direction perpendicular to the transport path by a distance corresponding to a positional or rotational error of the substrate.

20. A printing apparatus as described in claim 19, further comprising a third linear converter connecting the first member of the print head assembly to a second member, the third linear converter moving the second member of the print head assembly and the print head relative to the first member in a direction perpendicular to the track by a distance corresponding to a position or rotation error of the print head.

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