Jet control using an imager

Abstract

A printing system includes a substrate support, a printhead assembly positioned facing the substrate support, and an imager. The printhead assembly includes a plurality of dispensing nozzles extending in a jetting direction toward the substrate support, and a plurality of markers. The imager is movable relative to the printhead assembly and is directed in a direction opposite the jetting direction to capture at least one image including the plurality of markers indicative of locations of the plurality of dispensing nozzles in the printhead assembly.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 775,955, filed December 6, 2018, which is incorporated herein in its entirety. TECHNICAL FIELD

[0003] Embodiments of the present application generally relate to inkjet printing systems. In particular, the present application describes methods, systems, and / or apparatuses for jet control in inkjet printing systems. BACKGROUND

[0004] Inkjet printing is common in both office and home printers, as well as in industrial scale printers used to manufacture displays, print large scale writing materials, add materials to finished products (e.g., PCB’s), and construct biological products (e.g., tissue). Most commercial and industrial inkjet printers, as well as some consumer printers, use piezoelectric dispensers to apply printing material to a substrate. A piezoelectric material is disposed near a printing material reservoir. By applying a voltage to the piezoelectric material, it is deformed, which exerts a compressive force on the printing material reservoir, which is configured to eject printing material when subjected to a compressive force.

[0005] Some inkjet printing applications rely on extremely precise positioning of dispensing nozzles and / or printing substrates. From this perspective, the present application proposes methods, systems, and / or apparatuses for controlling printing material ejection in inkjet printers. SUMMARY

[0006] In one embodiment, a printing system includes a substrate support, a printhead assembly facing the substrate support, and an imager. The printhead assembly includes a plurality of dispensing nozzles extending in an ejection direction toward the substrate support and a plurality of markers. The imager is movable relative to the printhead assembly and faces in a direction opposite the ejection direction for capturing at least one image including the plurality of markers indicative of positions of the plurality of dispensing nozzles in the printhead assembly.

[0007] In a printing method according to one embodiment, an imager captures at least one image of a plurality of markers of a printhead assembly. The plurality of markers is detected in the at least one image captured by the imager. Positions of a plurality of dispensing nozzles in the printhead assembly are determined from the detected plurality of markers. Printing material is ejected from the plurality of dispensing nozzles onto a substrate while the substrate is moved relative to the printhead assembly according to the detected positions of the plurality of dispensing nozzles.

[0008] In one embodiment, a printing system includes a substrate support, a printhead assembly positioned toward the substrate support, a first imager, a second imager, and a controller. The printhead assembly includes a plurality of dispensing nozzles extending toward the substrate support in a jetting direction, and a plurality of first indicia. The first imager is movable relative to the printhead assembly and is oriented toward a direction opposite the jetting direction to capture at least one first image including the plurality of first indicia indicative of positions of the plurality of dispensing nozzles in the printhead assembly. The second imager is movable relative to the substrate support and is oriented toward the substrate support to capture at least one second image of a substrate on the substrate support. The controller is configured to control ejection of printing material from the plurality of dispensing nozzles onto the substrate based on the at least one first image and the at least one second image.

[0009] In one embodiment, a flat panel display is manufactured by a printing method in which an imager captures at least one image of a plurality of indicia in a printhead assembly. The plurality of indicia is detected in the at least one image captured by the line-scan imager. Positions of a plurality of dispensing nozzles in the printhead assembly are determined from the detected plurality of indicia. Printing material is ejected from the plurality of dispensing nozzles onto a substrate while the substrate is moved relative to the printhead assembly according to the detected positions of the plurality of dispensing nozzles. BRIEF DESCRIPTION OF DRAWINGS

[0010] Various aspects of the disclosure can be best understood from the following detailed description when read with the accompanying drawings in which: It is noted that the various features are not drawn to scale. In fact, the dimensions of the various features can be arbitrarily expanded or reduced for the sake of discussion.

[0011] Figure 1 is a top isometric view of a printing system according to one embodiment.

[0012] Figures 2A-2B is a side view schematic of a printing system according to one embodiment showing a printhead assembly in different positions. Figure 2C is a top view schematic of a printing system according to another embodiment.

[0013] Figures 3A-3B is a plan view schematic of an imager and a printhead assembly according to various embodiments.

[0014] Figure 4 is a flowchart of a printing method according to one embodiment.

[0015] Figure 5A is a side view schematic of a printing system according to one embodiment.

[0016] Figure 5BThis is a planar schematic diagram of an imager and a substrate according to one embodiment.

[0017] Figure 6 This is a flowchart of a printing method according to one embodiment.

[0018] Figure 7 This is a block diagram of a controller according to one embodiment.

[0019] Detailed description

[0020] The following disclosure provides various embodiments or examples for implementing different features of the given subject matter. To simplify this disclosure, specific examples of components, values, operations, materials, configurations, etc., are described below. Of course, these are merely examples and not intended to be limiting. Other components, values, operations, materials, configurations, etc., may also be considered. For example, reference numerals and / or letters may be repeated in various examples. Repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” “higher,” etc., may be used herein to facilitate the description of the relationship between one element or feature shown in the figures and another element or feature. Spatially relative terms are intended to encompass different orientations of the device in use or operation, other than those shown in the figures. The device may be positioned in other ways (rotated 90 degrees or otherwise oriented), and the spatially related descriptors used herein may be interpreted accordingly.

[0021] To achieve the desired high-quality printed products, some inkjet printing applications rely on the high-precision positioning of the nozzles and / or the printing substrate. Nozzle mapping is performed to precisely position the nozzles, mapping their positions to corresponding locations in the inkjet printing system reference frame. These mapped nozzle positions are then used in high-precision printing. The nozzle positions for nozzle mapping are obtained from image data captured by a line scanning imager, in which image sensors are arranged in a straight line. Compared to other methods that utilize multi-column and multi-row arrays of image sensors to capture image data, using a line scanning imager significantly reduces the time and complexity associated with image data capture, thereby accelerating the printing process.

[0022] Figure 1 This is a top isometric view of a printing system according to one embodiment.

[0023] The printing system 100 has a substrate support 102, a printing assembly 104, and a gantry assembly 106 for manipulating a substrate for printing. The printing system 100 is built on a base 108, which in one embodiment is a massive object to minimize vibrations transmitted to the operational components of the printing system 100. In one example, the base 108 is a block of granite. The substrate support 102 is positioned above the substrate 108 and includes a support surface 110 and means for making the support surface 110 substantially frictionless. In one example, the support surface 110 is an air table that provides an air cushion on which the substrate floats. The support surface 110 has a plurality of holes 112 that allow jets of gas to be ejected to provide an upward force to hold the substrate at a desired height above the support surface 110. Some of the holes are configured to also allow gas to be extracted from the air cushion that is floating the substrate in a controlled manner to provide precise local control of the height of the substrate.

[0024] The printing assembly 104 includes a dispenser assembly 114 that is configured on a printing support 116. The printing support 116 is configured relative to the substrate support 102 to provide access for the dispenser assembly 114 to be positioned constructively relative to a substrate on the substrate support 102 to precisely apply printing material to the substrate. The printing support 116 includes a rail or beam 117 that traverses the substrate support 102 to allow the dispenser assembly 114 to traverse the substrate support 102 and deposit printing material on a substrate at any location from one side of the printing support 116 to the opposite side. In one embodiment, the printing support 116 is attached to and extends from the base 108 to provide a stable support for the dispenser assembly 114. Two gantries 120 extend from the base 108 on opposite sides of the substrate support 102 to the rail 117, which extends through the substrate support 102. In one embodiment, the gantries 120 and the rail 117 are made of the same material as the base 108. In one example, the gantries 120, the rail 117, and the base 108 are integrally formed from a block of granite.

[0025] The dispenser assembly 114 includes at least one printhead assembly 119 and a print assembly controller 118, wherein the print assembly controller 118 includes electronics and / or sensors for controlling functional parameters of the printhead assembly 119, such as the position, time, duration, type of printing material, and dispensing profile of the printhead assembly 119 along the print support 116. The printhead assembly 119 can be moved along the track 117 of the print support 116 by operating a print carriage 122 coupled to the print support 116 to translate the printhead assembly 119 from one end of the track 117 to the opposite end. In one example, the print carriage 122 is driven by an electric motor or a servo motor. Power and signal conduits are not shown for simplicity.

[0026] substrate ( Figure 1 (Not shown) The support assembly 106 is positioned below the printing assembly 104. The support assembly 106, upon loading, achieves secure contact with the substrate and moves the substrate along the substrate support 102 to position the substrate relative to the printing assembly 104, thereby precisely dispensing printing material onto the substrate. The support assembly 106 is located on one side of the substrate support 102 and extends along the substrate support 102 in a first direction, thereby translating the substrate in the first direction during printing. The first direction is... Figure 1 The first direction 124 is indicated by arrow 124. This first direction 124 is referred to as the "Y direction" or "scanning direction," and the printhead assembly 119, guided by the track 117, moves in a second direction substantially perpendicular to the first direction, wherein the track 117 is substantially perpendicular to the first direction. Figure 1 The second direction, indicated by arrow 126, extends in the middle. This second direction 126 is referred to as the "X-direction" or "cross-scan direction," and the track 117 is referred to as the "X-beam." A third direction substantially bisects the first and second directions. Figure 1 The X, Y, and Z directions are represented by arrow 125. The third direction 125 is referred to as the "Z direction." The X, Y, and Z directions are the coordinate axis directions serving as the reference frame for the printing system 100, as shown by arrows 124, 125, and 126. In at least one embodiment, the origin of the coordinate system is at a fixed point, for example, associated with the base 108.

[0027] The gantry assembly 106 is configured on a gantry assembly support 128, which in one embodiment is a rail that extends along an edge 130 of the substrate support 102 substantially the entire length of the substrate support 102 in the first direction. In one embodiment, the gantry assembly support 128 is attached to the base 108, providing a stable support for the gantry assembly 106. In one embodiment, the gantry assembly support 128 is made of the same material as the base 108. In one example, the gantry assembly support 128, base 108, and print support 116 are integrally formed from a piece of granite. The gantry assembly support 128 is referred to as a "Y-beam." The gantry assembly 106 moves along the gantry assembly support 128 during operation to position a securely held substrate at any position on the substrate support 102, and the print assembly 104 positions the print head assembly 119 to provide a path for dispensing print material into precise locations on the substrate, for example, through operation of the print assembly controller 118.

[0028] A system controller 129 receives signals from various sensors deployed throughout the print system 100 and sends signals to various components of the print system 100 to control printing. For example, the system controller 129 can be operatively coupled to the print assembly controller 118 and a gantry assembly controller 131 that controls operation of the gantry assembly 106 over a network. One or more of the substrate support 102, the print assembly 104, the gantry assembly 106, and other auxiliary systems, such as environmental control systems and material management systems, have sensors operatively coupled to the system controller 129 to send signals related to various component states to the system controller 129 during a print operation. The system controller 129 includes data and instructions to determine control signals to send to various controlled components in the print system 100. In one embodiment, two or more of the system controller 129, the print assembly controller 118, and the gantry assembly controller 131 are integrated into a single controller. In one embodiment, at least one of the system controller 129, the print assembly controller 118, and the gantry assembly controller 131 is implemented as multiple controllers distributed in the print system 100 and connected to each other over a network. Figure 7 An example configuration of a controller according to one embodiment is described. For simplicity, "controller" in the following description refers to any one or more controllers in the print system 100.

[0029] For precision inkjet printing, tiny droplets of printing material are placed accordingly within small areas of the substrate. For example, in some cases, printing material with droplet diameters of 10-30 μm is placed in areas of the substrate with dimensions of 25-200 μm. This is typically done as the substrate moves in the Y direction (scanning direction) to minimize printing time. Many factors complicate this extreme precision, such as minute defects in the dimensions and / or positions of the components of the printing system 100, dimensional variations due to temperature, inaccuracies in the substrate (e.g., misalignment of previously formed structures on the substrate), inaccuracies in the translational speeds of the substrate, the dispenser assembly 114, and the support assembly 106, and inaccuracies in the distance between the substrate and the printhead assembly 119. For example, in the frame of reference of the printing system 100, if the position of the dispensing nozzles in the printhead assembly 119 is not precisely known or controlled, it is difficult to control the droplets of printing material from the dispensing nozzles in the printhead assembly 119 so that the droplets reach the target position when the substrate is in the appropriate position. In this regard, nozzle mapping is performed to determine or control the position of the dispensing nozzles in the reference frame of the printing system 100. In other aspects, features of the substrate are mapped into the reference frame of the printing system 100 to compensate for any misalignment of the substrate.

[0030] Figures 2A-2B This is a side view schematic diagram of a printing system according to one embodiment, showing printhead assemblies located at different positions. In one embodiment, the printing system 200 includes one or more features of the printing system 100 described herein.

[0031] like Figures 2A-2B As shown, the printing system 200 includes the substrate support 102 and an imager 202, wherein the printhead assembly 119 is positioned toward the substrate support 102. Here, the imager 202 is a line scan imager, but other imagers may also be used. The printhead assembly 119 includes a plurality of dispensing nozzles 206 extending toward the substrate support 102 in the ejection direction 225. The printhead assembly 119 includes, as... Figures 3A-3B The displayed markings (also referred to as "shell markings"). The line scanning imager 202 is movable relative to the printhead assembly 119. For example, Figures 2A-2BThe different relative positions between the line scanning imager 202 and the printhead assembly 119 are shown. Here, the printhead assembly 119 is coupled to the track 117 via an air bearing assembly or other low-friction coupling tool (not shown), and a linear actuator coupled between the printhead assembly 119 and one or both supports 120 moves the printhead assembly 119 in the cross-scanning direction. The line scanning imager 202 is oriented in a direction opposite to the ejection direction 225 to capture images of at least one of the plurality of markers, wherein the plurality of markers are used to determine the position of the dispensing nozzle 206 in the printhead assembly. Figures 2A-2B In the example configuration shown, the jet direction 225 is opposite to the Z direction, and the line scanning imager 202 is oriented in the Z direction, which is opposite to the jet direction 225.

[0032] In one embodiment, the line scanning imager 202 is stationary relative to the substrate support 102. For example, the line scanning imager 202 is fixed to bracket 120A of two supports 120A, 120B, wherein these two supports 120A, 120B are similar to the bracket 120 of the printing system 100 and extend from the base 108 to opposite sides of the substrate support 102. The printhead assembly 119 is movable relative to the line scanning imager 202 and the substrate support 102 in the cross-scanning direction (X direction), for example, from... Figure 2A The middle position of the track 117 shown is towards Figure 2B The location shown is adjacent to the support 120A facing the line scanning imager 202. The printhead assembly 119 passes through a location... Figure 2B When the line scanning imager 202 is positioned near the indicated location, the printhead assembly 119 can be positioned within the image field of the line scanning imager 202, wherein the line scanning imager 202 captures at least one image facing the dispensing nozzle 206 of the line scanning imager 202. The captured image is transmitted to the controller 118 or another controller of the printing system 100, wherein the controller is coupled to... Figures 2A-2B The line scanning imager 202 shown.

[0033] The above arrangement of the line scan imager 202 is an example configuration. Other configurations are within the range of various embodiments. In one example, another imager 204, also a line scan imager in this case, is shown as the bracket 120B fixed to the opposite side of the substrate support 102 to image the dispensing nozzle 206 by moving the printhead assembly 119 to either side of the substrate support 102. In one embodiment, the line scan imager 204 is omitted, or more than two line scan imagers are included in the printing system 200. In another example, in at least one embodiment, the line scan imager 202, or the line scan imager 204, can be moved relative to the substrate support 102, for example, by a motor, to position it... Figure 2B The predetermined image capture position is shown, thereby capturing an image of the dispensing nozzle 206. For example... Figure 2B As shown, after capturing an image, the line scanning imager 204 is moved away from the image capture position, for example, retracted as indicated by arrow 251 or swung as indicated by arrow 252, to avoid interfering with the printing process. In yet another example, the line scanning imager is physically moved relative to the fixed printhead assembly 119, rather than moving the printhead assembly 119 above the stationary line scanning imager 202 for image capture, as... Figure 2B As shown, the line scanning imager 202 and the printhead assembly 119 can be physically moved one after the other to capture images. For example, the line scanning imager 202 can be coupled to the track 117 via a linear positioner, thereby allowing the line scanning imager 202 to be moved relative to the printhead assembly 119 to a position facing the printhead assembly 119 to capture images of the dispensing nozzles 206.

[0034] Figure 2C This is a top view schematic diagram of a printing system according to another embodiment. For simplicity, Figure 2C Some components, such as the substrate support 102 and the base 108, are omitted. Figure 2C In an example configuration, the line scanning imager 202 and / or the line scanning imager 204, for example, may be moved along the Y direction by a motor to scan and capture images of the dispensing nozzle 206. For example, the line scanning imager 202 is moved by an electric carriage ( Figure 2CThe line scan imager 202 is coupled to a track 274 that is located on and supported by the carriage 120A. The track 274 is connected to the carriage 120A by a connecting member 272. The line scan imager 202 is linearly movable along the track 274 between positions 202A and 202B, as indicated by arrow 276. In another example, the line scan imager 204 is coupled to a pivot 284 located on or supported by the carriage 120B by a swivel mount 282. The line scan imager 204 is pivotally movable about the pivot 284 between positions 204A and 204B, as indicated by arrow 286. If multiple cameras are used, each camera can be coupled to the printing system 200 by either of the two ways, and different cameras can use different types of couplings.

[0035] Figure 3A A top plan view of the line scan imager 202 and a bottom plan view of the printhead assembly 119 are shown in accordance with one embodiment. Figure 3A A top plan view of the line scan imager 202 (as Figure 2A shown looking down in the ejection direction 225) is placed in parallel with a bottom plan view of the printhead assembly 119 (as Figure 2A shown looking up in the Z direction) in a combined view. The nozzle surface 321 of the housing or body 330 of the printhead assembly 119 is shown. The dispensing end of each dispensing nozzle 206 is disposed on the nozzle surface 321.

[0036] The line scan imager 202 includes a plurality of image sensors 332. In Figures 3A-3BIn one embodiment, all of the image sensors 332 of the line scan imager 202 are arranged in a single row, such as row 331, along the scan direction (Y direction). In another embodiment (not shown), the image sensors 332 of the line scan imager 202 are arranged in multiple rows. For example, the image sensors 332 in a first row are configured as primary image sensors that capture the image data needed for nozzle mapping, and the image sensors 332 in a second row are configured as redundant or secondary sensors that provide image data in the event of failure of one or more primary image sensors. The image sensors 332 are optoelectronic devices that capture light reflected from the nozzle surface 321 of the printhead assembly 119 to the line scan imager 202 and register an electrical signal based on the captured light. As the printhead assembly 119 moves over and relative to the line scan imager 202 in the cross-scan direction (X direction), the image sensors 332 capture images of the printhead assembly 119. In this regard, the image capture performed by the line scan imager 202 is similar to that performed by a copier or scanner using a similar linear photosensor configuration. To acquire images of features having a size range of a few μm (e.g., 5 to 10 μm), the image sensors 332 are configured to provide high resolution, such as approximately 0.1 μm. Examples of image sensors include, but are not limited to, CMOS (complementary metal-oxide-semiconductor) sensors and CCD (charge-coupled device) sensors.

[0037] In one embodiment, ambient light provides the illumination needed for the line scan imager 202 to perform image capture. However, due to the optical properties of the line scan imager 202 operating environment, at least one light source (not shown) is provided in at least one embodiment to illuminate the nozzle surface 321 of the printhead assembly 119 during image capture. Various parameters of the light emitted by the light source, such as wavelength, intensity, pulsation, and / or angle of incidence, are selected and / or varied based on one or more considerations, including but not limited to, the reflective properties of the nozzle surface 321, the color and / or other optical properties of the marking on the dispensing nozzle 206 and the nozzle surface 321, and the atmosphere surrounding the line scan imager 202, which in one example is an inert environment. In one embodiment, visible light is used, while in other embodiments non-visible light (i.e., electromagnetic radiation outside the visible spectrum) is used to illuminate the nozzle surface 321 of the printhead assembly 119 during image capture. The light source can be integrated with the line scan imager 202, such as by being a white LED light source configured on the sensor surface of the line scan imager 202 that faces the nozzle surface 321 of the printhead assembly 119.

[0038] The dispensing nozzle 206 is visible at the nozzle surface 321 of the printhead assembly 119. Figures 3A-3B In the example configuration, the dispensing nozzles 206 are arranged in one or more rows extending in the X direction. For example, Figures 3A-3B The four rows of nozzles 206 shown correspond to four printheads 320, 322, 324, and 326. Figure 3A The number of rows and / or the number of distributing nozzles 206 in each row of the printhead assembly 119 shown are examples and vary with different printing systems and / or printhead assemblies. Some printhead assemblies do not have the distributing nozzles arranged in a specific pattern. In high-precision printing systems, each printhead assembly may have thousands of distributing nozzles. In one embodiment, such as Figure 3A As shown, the rows 331 of the image sensor 332 of the line scanning imager 202 are long enough to extend completely across each row of dispensing nozzles 206 in the Y direction. Alternatively, without arranging the dispensing nozzles in the printhead assembly in a particular pattern, a single row 331 of the image sensor 202 of the line scanning imager 202 is long enough to extend completely across the entire width (Y direction) of the nozzle surface area where all dispensing nozzles are configured. Therefore, with this configuration, the printhead assembly 119 can be captured in a single scan in the X direction by the line scanning imager 202, thereby capturing an image covering or including all dispensing nozzles 206 of the printhead assembly 119.

[0039] However, if the length of the row 331 is insufficient to cover all the distributing nozzles 206 at once (i.e., the row scanning lens is smaller than the width of the nozzle surface 321, such as...) Figure 2C As shown), multiple passes of the multi-line scanning imager 202 / 204 and / or at least one line scanning imager 202 / 204 can be used to acquire multiple images, each image covering a corresponding portion of the nozzle surface 321. For example, Figure 2C The described configuration can be used to move the line scan imager 202 / 204 to a new position to capture an image of another portion of the nozzle surface 321. Alternatively, along... Figure 2C Two or more cameras 202 can be configured in the y-direction to perform a single scan of the entire nozzle surface 321. For example, multiple images are stitched together by the controller 118 into a larger image that covers all the assigned nozzles 206 of the printhead assembly 119 used for nozzle mapping.

[0040] Generally, the line scan imager 202 (or 204) typically includes multiple image sensors arranged in rows along a first direction, with the line scan imager and nozzle surface 321 moving relative to each other in a second direction perpendicular to the first direction. Thus, the image sensors scan through the nozzle surface 321. If the area to be scanned on the nozzle surface 321 is larger in the first direction than the length of the line scan imager in the first direction, using a single line scan imager would require repositioning the nozzle surface 321 after one scan for a second scan to scan areas not reached in the first scan, thus increasing the time required to complete the scan. In this case, two or more line scan imagers can be used simultaneously to scan an area larger than that accessible by one of the line scan imagers in a single scan. The two or more line scan imagers can be adjacent or non-adjacent, and the images captured by the two or more line scan imagers can be combined into a composite image for processing, or processed individually. For example, if one or more marks on the nozzle surface 321 are to be imaged, and the area occupied by the one or more marks cannot be imaged by a single-line scanning imager in a single scan, then two or more line scanning imagers can be used to scan and image the area where the marks are located, or any part of the area where the marks are located, where the area is larger than the field of view of a single-line scanning imager. The entire area where the marks are located can be imaged by multiple line scanning imagers that image adjacent parts of the area where the marks are located, and the images can be combined into a composite image of the entire marked area. Alternatively, two or more line scanning imagers can be used to image portions of the marked area that are spaced apart, where the distance prevents a single line scanning imager from accessing these portions in a single scan. Furthermore, if the distribution nozzle is to be imaged, and the area to be imaged is larger than the field of view of a single line scanning imager, then two or more line scanning imagers can be used in the manner described above.

[0041] exist Figure 3AIn the example configuration of FIG. 1, there are four rows of dispensing nozzles 206 in the plurality of printheads, with each row belonging to a respective printhead 320, 322, 324, 326. Each printhead 320, 322, 324, 326 is implemented in the form of a cartridge or card that is removably configured within a respective slot or area in the middle region 327 of the nozzle surface 321 of the printhead assembly 119. Once installed within the respective slot or area in the middle region 327, the printhead 320, 322, 324, 326 is coupled for print material and control signals such that the dispensing nozzles of the printhead 320, 322, 324, 326 eject print material onto a substrate supported by the substrate support 102. In one embodiment, the printhead 320, 322, 324, 326 has a piezoelectric material or sensor (not shown) corresponding to the dispensing nozzles 206. Upon receiving a control signal, the piezoelectric material or sensor deforms and causes the print material to be ejected from the corresponding dispensing nozzles 206 on the substrate. Other configurations can also be used, such as other types of sensors and / or dispensing nozzle configurations. The printheads 320, 322, 324, 326 can be removed from the printhead assembly 119 for servicing, maintenance, and / or replacement, and then installed back into the printhead assembly 119. The repeated removal and installation of the printheads 320, 322, 324, 326 and related handling and / or installation errors can change the position or orientation of the dispensing nozzles 206 in the printhead assembly, which in turn can cause misalignment between the dispensing nozzles and the intended print area on the substrate, and can result in defective print products. To address this issue, the methods and apparatus described herein can be used to map the positions of the nozzles.

[0042] To perform nozzle mapping on or in the housing or subject 330, the printhead assembly 119 has a plurality of housing markers, here four housing markers 310, 312, 314, 316, for determining the positions of the dispensing nozzles 206 in the printhead assembly 119. In the example configuration of FIG. 1, the housing markers 310, 312, 314, 316 are located on the printhead assembly 119. In other embodiments, the housing markers 310, 312, 314, 316 can be located on the substrate support 102 or other component of the printing system 100. Figure 3A In the example configuration of FIG. 1, the housing markers 310, 312, 314, 316 are located on the printhead assembly 119. In other embodiments, the housing markers 310, 312, 314, 316 can be located on the substrate support 102 or other component of the printing system 100. Figure 3AIn the example configuration shown, the housing marks 310, 312, 314, 316 are arranged about the middle region 327, with the dispensing nozzle 206 located in the middle region. However, other configurations of housing marks 310, 312, 314, 316 on the nozzle surface 321 and / or with respect to the dispensing nozzle 206 can be used. In one embodiment, the housing marks 310, 312, 314, 316 are referred to as "fiducial marks" and have one or more known attributes, such as a pattern, orientation, size, and location on the nozzle surface 321 of the printhead assembly 119. The housing marks 310, 312, 314, 316 are affixed (e.g., by adhesive), etched, machined, printed, or sprayed on the nozzle surface 321 of the printhead assembly 119. Other ways of providing fiducial marks for a printhead assembly are also possible. In Figure 3A In the example configuration shown, the number and / or shape of the housing marks 310, 312, 314, 316 is exemplary. Any number and / or shape and / or material and / or orientation of the housing marks 310, 312, 314, 316 can be used. In one example, any of the housing marks 310, 312, 314, 316 can include text, a bar code, a company name, and / or a logo. The location of the dispensing nozzle 206 determined with the housing marks 310, 312, 314, 316 is more accurate with more fiducial marks and / or more complex mark shapes.

[0043] To determine the position of the dispensing nozzles 206 in the printhead assembly 119 using the housing marks 310, 312, 314, 316, the line-scan imager 202 is controlled by the controller 118 to capture images of the nozzle surface 321 of the printhead assembly 119 as the printhead assembly 119 passes the line-scan imager 202. Additionally, to determine the position of the dispensing nozzles 206 in the printhead assembly 119 using the housing marks 310, 312, 314, 316, the line-scan imager 202 is controlled by the controller 118 to capture images of the nozzle surface 321 of the printhead assembly 119 as the printhead assembly 119 passes the line-scan imager 202 is performed while the line-scan imager 202 moves the printhead assembly 119 in a cross-scan direction. The captured images are transmitted from the line-scan imager 202 to the controller 118, where the controller 118 detects the housing marks 310, 312, 314, 316 and at least one dispensing nozzle 206 from the captured images. Image processing algorithms and / or software and / or programs to identify objects by known attributes such as pattern, position, size, and / or orientation are known image processing techniques and are not described in detail herein. In one embodiment, the controller 118 relies on these known algorithms and / or software and / or programs to identify the housing marks 310, 312, 314, 316 and at least one dispensing nozzle 206 from the captured images.

[0044] In at least one embodiment, the known attributes of the housing indicia 310, 312, 314, 316, such as one or more patterns, positioning, dimensions, location, and the known shape (e.g., circular) and size of each of the dispensing nozzles 206 and their expected position relative to the housing indicia 310, 312, 314, 316 are used by the controller 118. For example, the known attributes of the housing indicia 310, 312, 314, 316 are included in printhead assembly configuration data stored in and / or accessible by the controller 118. The printhead assembly configuration data can also include other data related to the dispensing nozzles 206, including but not limited to one of the following: number of rows of dispensing nozzles, number of dispensing nozzles per row, spacing between adjacent dispensing nozzles in a row or column, spacing between adjacent rows and / or columns, spatial relationship between each row of dispensing nozzles and the housing indicia, etc. In one aspect, the printhead assembly configuration data is a coordinate map representing the housing indicia and the dispensing nozzles, e.g., a series of x-y locations on or within the housing indicia and the dispensing nozzles. From the printhead assembly configuration data, the controller 118 is able to determine the expected position of each of the dispensing nozzles 206 relative to the housing indicia 310, 312, 314, 316. Once the housing indicia 310, 312, 314, 316 and at least one of the dispensing nozzles 206 are identified by the controller 118 from the captured image, the position thereof as identified from the captured image is compared to the position thereof known / expected from the printhead assembly configuration data. From the comparison, the controller 118 derives a transformation relationship between the position as identified from the captured image and the known / expected position from the printhead assembly configuration data. The controller 118 uses the derived relationship and the expected positions of all other dispensing nozzles 206 to interpolate the positions of all other dispensing nozzles 206 in the printhead assembly 119, e.g., using bilinear interpolation, which includes one or more interpolation operations such as translation, rotation, skew, scaling, etc. This determines the positions of all of the dispensing nozzles 206 in the printhead assembly 119.

[0045] The controller 118 then maps the determined positions of all of the dispensing nozzles 206 in the printhead assembly 119 to corresponding positions in the frame of reference of the printing system, e.g., a coordinate system having coordinate axes in the X, Y, and Z directions as discussed herein. This is possible because the printhead assembly 119 has at least one known position in the frame of reference of the printing system controlled by the controller 118. In one embodiment, the operation of mapping the determined positions of all of the dispensing nozzles 206 to corresponding positions in the frame of reference of the printing system involves bilinear interpolation, which includes one or more interpolation operations such as translation, rotation, skew, scaling, etc.

[0046] Based on the mapped position of the dispensing nozzles 206 in the printing system frame of reference, the controller 118 controls ejection of printing material from the dispensing nozzles 206 onto a substrate supported by the substrate support 102. Since the mapped position of the dispensing nozzles 206 accurately reflects the actual detected position of the dispensing nozzles 206, printing accuracy is improved.

[0047] Figure 3B A plan view of the line scan imager 202 and print head assembly 319 according to one embodiment. In one embodiment, the print head assembly 319 includes one or more features of the printhead assembly 119 described herein. Figure 3B A top plan view of the line scan imager 202 (looking down the ejection direction 225) and a bottom plan view of the print head assembly 319 (looking up the Z direction 225) are shown. Figure 2A A top plan view of the line scan imager 202 (looking down the ejection direction 225) and a bottom plan view of the print head assembly 319 (looking up the Z direction 225) are shown. Figure 2A A top plan view of the line scan imager 202 (looking down the ejection direction 225) and a bottom plan view of the print head assembly 319 (looking up the Z direction 225) are shown.

[0048] In contrast to the printhead assembly 119, the print head assembly 319 also includes a plurality of print head marks having predetermined (or known) positions relative to the dispensing nozzles 206. As with the housing marks 310, 312, 314, 316, any number and / or shape and / or material and / or positioning of the print head marks is suitable. For example, print head 320 includes print head marks 340, 342 having predetermined positions relative to the dispensing nozzles 206 of the print head 320. Each of the other print heads 322, 324, 326 includes similar print head marks having predetermined positions relative to the dispensing nozzles 206 of the respective print heads 322, 324, 326. The following description is directed to the print head 320, but is also applicable to the other print heads 322, 324, 326.

[0049] In at least one embodiment, the print head marks 340, 342 are formed on or in the bottom surface of the print head 320 so as to have a fixed positional relationship with the dispensing nozzles 206 in the print head 320. Similar to the housing marks 310, 312, 314, 316, the print head marks 340, 342 can be formed by any suitable technique, such as etching, stamping, molding, etc. Figure 3AThe line-scan imager 202 is controlled by the controller 118 to capture images of the nozzle surface 321 of the printhead assembly 319 as the printhead assembly 319 passes the line-scan imager 202, as described above. The captured images are transmitted from the line-scan imager 202 to the controller 118, where the controller 118 detects the housing marks 310, 312, 314, 316 and the printhead marks 340, 342 from the captured images. From the printhead assembly configuration data, the controller 118 is able to determine the expected positions of the printhead marks 340, 342 relative to the housing marks 310, 312, 314, 316. Once the housing marks 310, 312, 314, 316 and the printhead marks 340, 342 are identified by the controller 118, the controller 118 derives a transformation relationship between the positions and orientations identified from the captured images and the known / expected positions and orientations from the printhead assembly configuration data. The controller 118 uses the derived relationship and the expected positions and orientations of the printhead marks 340, 342 to interpolate their positions and orientations in the printhead assembly 319, which in turn are used by the controller 118 to interpolate the positions of the dispensing nozzles 206 of the printhead 320 in the printhead assembly 319. The described process is applied to the other printheads 322, 324, 326. Thus, the positions of all the dispensing nozzles 206 in the printhead assembly 319 can be accurately determined. The controller 118 then performs nozzle mapping and print material ejection control based on the determined positions of the dispensing nozzles 206, as described above. Figure 3A

[0050] In at least one embodiment, since the printhead marks 340, 342 are fixed to the printhead 320, the detachment / attachment of the printhead 320 from / to the printhead assembly 319 does not affect the positional relationship between the printhead marks 340, 342 and the dispensing nozzles 206 in the printhead 320. Thus, the positions of the dispensing nozzles 206 of the printhead 320 can be determined by detecting the printhead marks 340, 342, rather than having to detect the dispensing nozzles 206 themselves, as in the prior art. Figure 3A ​The print head assembly 119 is shown as having at least one of the plurality of dispensing nozzles 206 directly detected. In one embodiment, the print head indicia 340, 342 are larger in size and more unique in shape (i.e., more easily identifiable) than the small (diameter in μm) circular dispensing nozzles 206 that are densely packed. Thus, detection of the print head indicia 340, 342 by the controller 118 is simpler than detection of the dispensing nozzles 206, which in turn improves at least one of speed or accuracy in the nozzle mapping process. This effect is particularly pronounced in inkjet printing applications, where there can be thousands of small dispensing nozzles 206 packed closely together in a print head assembly 119, and where it can be difficult to identify one or more dispensing nozzles from a captured image, particularly when the dispensing nozzles are obscured by printing material from a previous printing operation. Although one embodiment provides a cleaning mechanism (not shown) for cleaning the dispensing nozzles 206 prior to image capture, it is still beneficial to provide the print head indicia 340, 342 in a fixed positional relationship to the dispensing nozzles 206 for nozzle mapping.

[0051] Figure 4 FIG. 4 is a flowchart of a print method 400 according to one embodiment. The print method 400 can be performed by at least one controller described herein, or under the control of the controller. In the following description, the print method 400 is performed by or under the control of the controller 118.

[0052] In operation 405, the controller causes an imager to capture at least one image of a plurality of indicia of a print head assembly. For example, the controller 118 causes the line scan imager 202 to capture at least one image of the plurality of indicia 310, 312, 314, 316 of the print head assembly 119. Figure 2B The line scan imager 202 is moved about the image capture position. The controller 118 further causes the line scan imager 202 to capture an image of a nozzle surface 321 of the print head assembly 119 as the line scan imager 202 passes over the print head assembly 119. The captured image includes at least the plurality of indicia 310, 312, 314, 316 of the print head assembly 119.

[0053] In operation 415, the controller detects the plurality of indicia in the at least one image captured by the imager. For example, the controller 118 detects or identifies the plurality of indicia 310, 312, 314, 316 in the image captured by the line scan imager 202, by using one or more known image processing algorithms and / or software and / or programs described herein.

[0054] In operation 425, the controller detects the positions of the plurality of dispensing nozzles in the printhead assembly from the detected plurality of markers. In one example, the controller 118 detects or identifies at least one dispensing nozzle 206 and uses the detected position of the at least one dispensing nozzle 206 and the detected positions of the housing markers 310, 312, 314, 316 to determine the positions of all other dispensing nozzles 206 in the printhead assembly 119, as described in Figure 3A In another example, the controller 118 detects or identifies printhead markers 340, 342, which have predetermined positions relative to the dispensing nozzles 206 of the printhead 320, and uses the detected positions of the housing markers 310, 312, 314, 316 and the detected printhead markers 340, 342 to determine the positions of all dispensing nozzles 206 in the printhead assembly 319, as described in Figure 3B Thus, while it can not be possible or practical to directly image and identify all dispensing nozzles of a printhead assembly, by imaging and identifying housing markers of the printhead assembly and nozzle or printhead markers associated with dispensing nozzles, the positions of all dispensing nozzles in the printhead assembly can be determined.

[0055] In operation 435, the controller controls the ejection of print material from the plurality of dispensing nozzles on the substrate based on the detected positions of the plurality of dispensing nozzles. For example, based on the known position of the printhead assembly in the print system frame of reference described herein, the controller 118 maps the determined positions of the dispensing nozzles 206 of the printhead assembly 119 or 319 to corresponding positions in the print system frame of reference. The controller 118 then uses the mapped positions of the dispensing nozzles 206 in the print system frame of reference to control when and / or which dispensing nozzles are to eject print material according to a recipe, where the recipe includes print data or coordinates in the print system frame of reference. This results in a high precision printed product. For example, if a printing nozzle is found at a position that is a distance d from an intended position, then a drop ejected according to an existing print plan will land at a position that is a distance d from a target position t. If the x-component of the distance d is d x , then the printhead assembly can be adjusted -d x to compensate. If the average distance that a printing nozzle is offset from its intended position in the x-direction is d , then the printhead assembly can be adjusted -d to compensate. If the distance d has a y-component d y , then the print plan can be adjusted with a global firing delay d y / v, where v is the translational speed of the substrate in the y-direction, and for an average distance of the y-component as well.

[0056] In one embodiment, the printed products produced by the printing method include, but are not limited to, solar panels and flat panel displays such as organic light emitting diode (OLED) displays.

[0057] In one embodiment, the nozzle mapping described herein is performed at the beginning of a print system initialization and / or between print operations. In at least one embodiment, the nozzle mapping described herein is performed during a print operation, for example, by moving the printhead assembly 119 from a print position Figure 2A to an image capture position Figure 2B as shown, to perform image capture and nozzle mapping, and then returning the printhead assembly 119 to the print position to continue the print operation according to the nozzle mapping results.

[0058] In one embodiment, a line scan imager is used having a line of photosensors that is at least as wide as the range of the dispensing nozzles in the printhead assembly. Thus, a high resolution image covering all of the dispensing nozzles can be obtained by the line scan imager in one pass over the printhead assembly, thereby saving printer initialization time and / or reducing print interruptions.

[0059] Other methods utilize image sensor arrays arranged in multiple columns and rows to capture image data, in contrast to which one embodiment using a line scan imager significantly reduces the time and complexity associated with image data capture, which in turn can speed up nozzle mapping, printer initialization, and / or the printing process. In some cases, a common camera with an array of photosensors can take 15-20 minutes to capture a high quality image sufficient for nozzle mapping, whereas a line scan imager according to one embodiment can take only a few minutes to capture a high resolution image suitable for nozzle mapping under the same circumstances. The reason is that a common camera has to capture an acceptable image of thousands of densely arranged dispensing nozzles, so the common camera should be properly aligned with the printhead assembly. Such camera alignment takes time. Although such an imager can be used with the methods and apparatus described herein, in most cases using a line scan imager for image capture eliminates the need for camera alignment; instead, a simple single pass of the line scan imager over the printhead assembly is sufficient to achieve high quality, high resolution image capture. Even if several passes of imaging are required for the entire nozzle surface as discussed herein, the imaging speed is still improved over other methods using a conventional camera. Thus, in addition to higher throughput, the imaging is faster and the time interval between measurements is shorter. As a result, more frequent measurements and / or corrections can be made during a print operation, thereby improving print accuracy.

[0060] Figure 5Ais a side view schematic of a printing system 500 according to an embodiment. In one embodiment, the printing system 500 includes one or more features of the printing system 100 and / or the printing system 200 described herein.

[0061] In comparison to the printing system 200, the printing system 500 further includes a second imager 502 that is movable relative to the substrate support 102 and in a direction towards the substrate support 102 to capture at least one second image of the substrate 508 on the substrate support 102. In one example, the substrate 508 is a glass substrate. Other substrate materials are within the scope of various embodiments. In Figure 5A In the example configuration shown, the imager 502 is attached to the print carriage 122 to be movable relative to the substrate 508 together with the print head assembly 119. In another example configuration (not shown), the imager 502 is movable and independent of the print head assembly 119, e.g., by a drive shaft or motor. For example, the imager 502 can have its own actuation coupling with the track 117, which can be actuated independently.

[0062] Figure 5B is a plan view schematic of the imager 502 and the substrate 508 according to an embodiment. Figure 5B shows a top plan view of the substrate 508 (from Figure 5A shown looking down the ejection direction 225), and a bottom plan view of the imager 502 (from Figure 5A shown looking up the Z direction).

[0063] The substrate 508 includes at least one print region in which print material droplets ejected from the dispensing nozzles land and are later processed to form a permanent portion of a print product. In Figure 5B In the example configuration shown, the substrate 508 includes 7 print regions sp1-sp7, each of which corresponds to, e.g., a display panel to be manufactured. To identify the location of the print regions, the substrate 508 includes a plurality of substrate marks for each print region. In Figure 5B In the example configuration shown, each print region includes four substrate marks on its corners. In Figure 5BFor simplicity, only substrate markings 510, 512, 514, and 516 are used to identify the sp1 printing area, and substrate markings 520, 522, 524, and 526 are used to identify the sp3 printing area. In one embodiment, the substrate markings are referred to as "reference markings" and have one or more known properties, such as patterns, orientations, dimensions, and positions on the substrate 508. The substrate markings are attached (e.g., by adhesive), etched, machined, printed, or sprayed onto the substrate 508. Other methods of providing substrate markings to the substrate may also be used. Figure 5B The number and / or shape of the substrate markings in the example configuration shown are for illustrative purposes. Any of the following can be used: the number and / or shape of the substrate and / or the material and / or the orientation of the substrate markings. Any substrate marking can include text, barcodes, company names, and / or logos. With more substrate markings and / or more complex marking shapes, the location of the printed area defined by the substrate markings is more precise.

[0064] To determine the location of the printed area sp1 using the substrate markings 510, 512, 514, and 516, the controller 118 controls the imager 502 to capture at least one image of the substrate 508 as the substrate 508, for example, passes under the imager 502 in the Y direction. The captured image is transmitted from the imager 502 to the controller 118, wherein the imager may be a line scan imager, and the controller 118 detects at least the substrate markings 510, 512, 514, and 516 from the captured image. In one example, all substrate markings 510, 512, 514, and 516 are captured in a single image. In a further example, substrate markings 510 and 512 are captured in one image, while other substrate markings 514 and 516 are captured in another image. In yet another example, each of the substrate markings 510, 512, 514, and 516 is captured in a separate image. Image processing algorithms and / or software and / or programs for identifying objects based on known attributes of the objects are known image processing techniques, such as pattern, position, size, and / or orientation, which will not be described in detail herein. In one embodiment, the controller 118 relies on these known algorithms and / or software and / or programs to identify more markers 510, 512, 514, 516 from the captured image in a manner similar to that used to identify the shell markers 310, 312, 314, 316, as... Figures 3A-3B As shown.

[0065] Then, in a manner similar to mapping the defined position of the dispensing nozzle 206 to a corresponding position in the printing system reference system, the controller 118 maps the position of the printing area sp1 indicated by the detected substrate markings 510, 512, 514, 516 to a corresponding position in the printing system reference system, such as... Figures 3A-3B As shown. It should be noted that different mapping algorithms can be used to map different marks or different sets of marks. For example, the first algorithm can be used to map the shell marks 310, 312, 314 and 316, while the second algorithm, which is different from the first algorithm, can be used to map the substrate marks 510, 512, 514 and 516.

[0066] based on Figures 3A-3B The mapping position of the dispensing nozzle 206 in the printing system reference frame shown, and Figure 5B The mapping position of the printing area sp1 in the printing system reference frame is shown. The controller 118 controls the ejection of printing material from the dispensing nozzle 206 to the printing area sp1 of the substrate 508. In one embodiment, the ejection control of the printing material includes physical adjustments to the substrate 508 and / or the printhead assembly 119, and / or logical modifications to printing data, which will be used to generate control signals for the dispensing nozzle 206. Because the mapping position of the dispensing nozzle 206 and the printing area sp1 accurately reflects the actual positions of the dispensing nozzle 206 and the printing area sp1, printing accuracy is improved.

[0067] In at least one embodiment, when one printing area of ​​the substrate is printed, substrate marks used to identify another printing area on the same substrate are imaged and identified. For example, when printing area sp1 of substrate 508 is printed by the back-and-forth movement of substrate 508 in the Y direction, the substrate marks 520, 522, 524, and 526 used to identify another printing area sp3 are imaged during the same back-and-forth movement of substrate 508 in the Y direction. Therefore, when the printing operation in printing area sp1 is completed, the substrate marks 520, 522, 524, and 526 have been detected, and the position of the corresponding printing area sp3 has been mapped to the reference frame of the printing system, so that printing area sp3 is immediately ready for its printing operation. Therefore, the entire printing process of substrate 508 can be accelerated in at least one embodiment.

[0068] Figure 6is a flowchart of a printing method 600 according to an embodiment. The printing method 600 can be performed by at least one controller described herein, or under the control of the controller, in the printing system 500. In the following description, the printing method 600 is performed by or under the control of the controller 118.

[0069] In operation 605, the controller causes a first imager to capture at least one first image including a plurality of first markers for determining positions of a plurality of dispensing nozzles in a printhead assembly. For example, the controller 118 causes the printhead assembly 119 to move the row scan imager 202 near the image capture position. The controller 118 further causes the row scan imager 202 to capture an image of a nozzle surface 321 of the printhead assembly 119 as the row scan imager 202 passes by the printhead assembly 119. The captured image includes at least a plurality of markers 310, 312, 314, 316 of the printhead assembly 119. Figure 2B The displayed image moves the row scan imager 202 near the image capture position. The controller 118 further causes the row scan imager 202 to capture an image of a nozzle surface 321 of the printhead assembly 119 as the row scan imager 202 passes by the printhead assembly 119. The captured image includes at least a plurality of markers 310, 312, 314, 316 of the printhead assembly 119.

[0070] In operation 615, the controller causes a second imager to capture at least one second image including a plurality of second markers for determining a position of a print area on a substrate. For example, the controller 118 causes the imager 502 to capture at least one second image of the substrate 508 as it passes under the imager in the Y direction, with the substrate markers 510, 512, 514, 516 (or the substrate markers 520, 522, 524, 526) identifying the print area sp1 (or sp3) expected. The substrate 508 passes under the imager 502 in the Y direction before (e.g., for identifying the print area sp1) or during (e.g., for identifying the print area sp3 while the print area sp1 is being printed) a printing operation of the substrate 508.

[0071] In operation 625, based on the at least one first image and the at least one second image, the controller controls ejection of print material from the plurality of dispensing nozzles to a print region of the substrate. For example, the controller 118 detects or identifies the plurality of marks 310, 312, 314, 316 obtained from the first image captured from the print head assembly 119 to determine the locations of the dispensing nozzles 206, and detects or identifies the plurality of substrate marks 510, 512, 514, 516 obtained from the second image captured from the substrate 508 to determine the location of the print region sp1. The controller 118 then maps the determined locations of the dispensing nozzles 206 and the print region sp1 to respective locations in the print system frame of reference. The controller 118 then uses the mapped locations of the dispensing nozzles 206 and the print region sp1 in the print system frame of reference to control when and / or which dispensing nozzles to eject print material in accordance with a recipe, which includes print data or coordinates in the print system frame of reference. As a result, a print product with high print accuracy can be obtained.

[0072] The described methods include example operations, but the example operations need not be performed in the order shown. Operations can be appropriately added, replaced, changed order, and / or eliminated, as appropriate, in accordance with the spirit and scope of the embodiments in this disclosure. Embodiments that combine different features and / or different embodiments are within the scope of this disclosure and will be apparent to those of ordinary skill in the art after review of this disclosure.

[0073] Figure 7 A block diagram of a controller according to one embodiment. According to Figures 1-6 the one or more units and / or systems and / or operations are implemented, in one embodiment, by Figure 7 one or more controllers 700.

[0074] The controller 700 includes a hardware processor 702 and a storage 704, which includes at least one non-transitory computer-readable storage medium, a bus 708, an I / O (input / output) interface 710, and a network interface 712. The processor 702 is connected with the storage 704, the I / O interface 710, and the network interface 712 through the bus 708. The network interface 712 can be connected to a network 714, so that the processor 702 and the storage 704 can communicate with other devices through the network 714. The processor 702 is configured to execute computer program instructions encoded by the storage 704 and / or access data stored in the storage 704, so as to cause the controller 700 to perform Figures 1-6 the one or more functions and / or operations.

[0075] The processor 702 includes one or more Central Processing Units (CPU), a plurality of processing units, a distributed processing system, an application-specific integrated circuit (ASIC), and / or a suitable hardware processing unit.

[0076] The storage device 704 includes one or more electronic, magnetic, optical, electromagnetic, infrared, and / or semiconductor system (or devices or apparatus) for the non-transitory storage of instructions and / or data. For example, the storage device 704 includes semiconductor or solid state memory, magnetic tape, a removable computer disk, Random Access Memory (RAM), Read Only Memory (ROM), a rigid magnetic disc, and / or an optical disc. By way of example, an optical disc includes a Compact Disc Read Only Memory (CD-ROM), a

[0077] The I / O interface 710 is circuitry that can be connected to external circuitry. For example, the I / O interface 710 includes one or more of a keyboard, a keypad, a mouse, a trackball, a trackpad, a cursor direction key, a card reader, a communication port, a display, a signal lamp, a printer, and / or an audio device for communicating information with the processor 702. In the present example, the I / O interface 710 is omitted.

[0078] The network interface 712 is circuitry that allows the controller 700 to communicate with the network 714, which is connected to one or more other controllers and / or image capture / processing devices. For example, the network interface 712 includes one or more wireless network interfaces such as Bluetooth, WIFI, WIMAX, GPRS, or WCDMA; or wired network interfaces such as ETHERNET, USB, or IEEE- 1394. In one example, the network interface 712 is omitted.

[0079] The controller 700 is configured to perform Figures 1-6 the described part or all of the functions and / or operations, and can achieve Figures 1-6 one or more advantages and / or effects described.

[0080] The above summarizes the features of several embodiments, so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art should recognize that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purpose and / or achieve the same advantages as the embodiments described herein. Those skilled in the art should also realize that such equivalent structures do not deviate from the spirit and scope of the present disclosure, and various changes, substitutions and modifications can be made without deviating from the spirit and scope of the present disclosure.

Claims

1. A printing system, characterized in that... include: A substrate support that supports the substrate and moves the substrate in the scanning direction; A printhead assembly positioned facing the substrate support, the printhead assembly comprising: Multiple dispensing nozzles extending toward the substrate support in the spraying direction; as well as Multiple benchmarks; and An imager, wherein the printhead assembly and the imager are movable relative to each other, and the imager is oriented in a direction opposite to the jet direction, for capturing an image including multiple reference marks indicating the positions of multiple dispensing nozzles in the printhead assembly, wherein The printhead assembly is movable relative to the imager and the substrate support in the cross-scanning direction and is positioned to place the dispensing nozzle and the reference mark in the imager's image field, so that the imager can capture the image as the printhead assembly passes through the imager. The imager is a line scanning imager, which has multiple image sensors arranged in rows along a scanning direction perpendicular to the cross scanning direction. The printhead assembly also includes a plurality of printheads, each printhead having a plurality of printhead markings at predetermined positions relative to the plurality of dispensing nozzles, and The printing system further includes a controller, the controller being configured to... Detect from the image captured by the imager The plurality of reference markers, and The multiple printhead markings, and Determine the positions of multiple distribution nozzles in the printhead assembly, based on The detected multiple reference markers, The detected multiple printhead marks, and The plurality of printhead markings are positioned relative to the plurality of dispensing nozzles at predetermined locations.

2. The printing system according to claim 1, characterized in that... Further includes: Controller, the controller is configured Mapping the positions of the multiple distribution nozzles in the printhead assembly to the corresponding positions in the reference system of the printing system, and Based on the mapped positions of the plurality of dispensing nozzles in the reference system of the printing system, the ejection of printing material from the plurality of dispensing nozzles is controlled.

3. The printing system according to claim 2, characterized in that... The controller is set to Detect from the image captured by the imager The plurality of reference markers, and The distribution nozzle among the plurality of distribution nozzles, and Determine the positions of the multiple dispensing nozzles in the printhead assembly, based on The detected reference marks, and the detected dispensing nozzles.

4. The printing system according to claim 1, characterized in that... The imager is fixed to the substrate support.

5. The printing system according to claim 4, characterized in that... The plurality of dispensing nozzles are arranged in at least one row along the cross-scanning direction.

6. The printing system according to claim 5, characterized in that... Further includes: A controller configured to control the line scanning imager to capture images including all of the plurality of assigned nozzles in a single pass of the printhead assembly along the cross-scanning direction by the line scanning imager.

7. The printing system according to claim 1, characterized in that... The imager can move relative to the substrate support in a swinging motion.

8. The printing system according to claim 1, characterized in that... The scanning direction is the Y direction, and the cross-scanning direction is the X direction.

9. A printing method, characterized in that... include: The imager captures images of multiple reference markers within the printhead assembly; Detect the plurality of reference markers in the image captured by the imager; The positions of multiple dispensing nozzles in the printhead assembly are determined based on the detected multiple reference marks; as well as Based on the detected positions of the plurality of dispensing nozzles, printing material is ejected from the plurality of dispensing nozzles onto the substrate, while simultaneously moving the substrate relative to the printhead assembly. in The printhead assembly includes: The casing has multiple reference marks, and Multiple printheads, which are detachably attached to the housing. Each of the multiple printheads includes: The corresponding dispensing nozzle group among the multiple dispensing nozzles in the printhead assembly, and Printhead markings, which have predetermined positions relative to the corresponding assigned nozzle groups. The method further includes detecting printhead marks of multiple printheads from images captured by the imager, and The determination of the positions of the multiple distribution nozzles in the printhead assembly is based on Multiple reference marks were detected on the casing. Printhead markings of multiple detected printheads, and Each printhead is marked with a predetermined position relative to the corresponding assigned nozzle group.

10. The printing method according to claim 9, characterized in that... Also includes: The defined positions of the multiple distribution nozzles in the printhead assembly are mapped to corresponding positions in the reference system of the printing system. Specifically, printing material is ejected from the plurality of dispensing nozzles based on their mapped positions in the reference system of the printing system.

11. The printing method according to claim 9, characterized in that... Also includes: Detecting the dispensing nozzles from the plurality of dispensing nozzles in the image captured by the imager. Among them, based on The detected multiple reference markers, and Detected dispensing nozzles, Determine the positions of the plurality of distribution nozzles in the printhead assembly.

12. The printing method according to claim 9, characterized in that: The image is captured while the imager moves the printhead assembly in the cross-scanning direction.

13. The printing method according to claim 12, characterized in that: The imager is a line scanning imager with multiple image sensors, and the image sensors are configured in a single row in the scanning direction perpendicular to the cross scanning direction. The plurality of dispensing nozzles are arranged in at least one row along the cross-scanning direction, and The line scanning imager captures the image during a single pass through the printhead assembly.

14. The printing method according to claim 13, characterized in that: The scanning direction is the Y direction, and the cross-scanning direction is the X direction.

15. A printing system, characterized in that... include: Substrate support; A printhead assembly positioned facing the substrate support, the printhead assembly comprising: A printhead having a plurality of dispensing nozzles extending toward the substrate support in the jetting direction; The outer shell; and Multiple reference marks on the casing; A first imager, movable relative to the printhead assembly and oriented in a direction opposite to the jetting direction, captures an image including the plurality of reference marks indicating the positions of a plurality of dispensing nozzles in the printhead assembly; and The controller, based on the image, controls the ejection of printing material from the plurality of dispensing nozzles onto the substrate. in The printhead assembly is movable relative to the first imager and the substrate support in the cross-scanning direction, and is positionable within the image field of the first imager. The first imager has multiple image sensors arranged along a scanning direction perpendicular to the cross-scanning direction, so that the printhead assembly passes through the image field of the first imager in a single pass along the cross-scanning direction. The first imager is capable of imaging all of the multiple dispensing nozzles. The reference mark is the first reference mark. The printhead assembly also includes a plurality of printheads, each printhead having a plurality of third reference marks at predetermined positions relative to the plurality of dispensing nozzles, and The controller is set to Detect from the image captured by the first imager Multiple first reference markers, and The plurality of third reference markers, and Determine the positions of multiple distribution nozzles in the printhead assembly, based on The detected plurality of first reference markers, The detected plurality of third reference markers, and The plurality of third reference marks are positioned relative to the predetermined positions of the plurality of dispensing nozzles.

16. The printing system according to claim 15, characterized in that: The image is a first image, and the printing system further includes: A second imager, movable relative to the substrate support and oriented toward the substrate support, captures a second image of the substrate on the substrate support. The controller is configured as follows: The second image captured by the second imager detects multiple second reference marks indicating the printed area on the substrate. The positions of the printed areas indicated by the detected plurality of second reference marks are mapped to the corresponding positions in the reference system of the printing system. Mapping the positions of the plurality of distributing nozzles in the printhead assembly to the corresponding positions in the reference system of the printing system, and Based on the mapping positions of the multiple dispensing nozzles and the printing area in the reference system of the printing system, the spraying of printing material from the multiple dispensing nozzles to the substrate is controlled.

17. The printing system according to claim 15, characterized in that: The controller is set to Detect from the image captured by the first imager The plurality of reference markers, and The distribution nozzle among the plurality of distribution nozzles, and Determine the positions of the plurality of distributing nozzles in the printhead assembly, based on The detected multiple reference markers, and Detected dispensing nozzles.

18. The printing system according to claim 15, characterized in that: The first imager is fixed to the substrate support.

19. The printing system according to claim 16, characterized in that: The first imager has multiple image sensors arranged along the scanning direction over the entire width of the area where all the multiple distributing nozzles are arranged, and The substrate support is configured to move the substrate under the second imager in a scanning direction perpendicular to the cross-scanning direction, such that the second imager can capture the second image as the substrate passes under the second imager.

20. The printing system according to claim 15, characterized in that... The first imager can move relative to the substrate support in a swinging motion.

21. The printing system according to claim 15, characterized in that... The first imager is movable relative to the substrate support to be positioned at a predetermined image capture location.

22. The printing system according to claim 16, characterized in that, The controller is used to control the printhead assembly to pass through the first imager, and to control the first imager to capture an image of the distributed nozzles of the printhead assembly as the printhead assembly passes through the first imager.

23. The printing system according to claim 17, characterized in that, The first imager is a line scanning imager.

24. The printing system according to claim 15, characterized in that, The scanning direction is the Y direction, and the cross-scanning direction is the X direction.

25. A printing system, characterized in that, include: A substrate support that supports the substrate and moves the substrate in the scanning direction; A printhead assembly positioned facing the substrate support, the printhead assembly comprising: A plurality of dispensing nozzles extending toward the substrate support in the spraying direction; and Multiple benchmarks; and The imager is oriented to capture an image that includes multiple reference markers. in The printhead assembly is movable relative to the imager and substrate support in the cross-scanning direction, so that the imager can capture the image as the printhead assembly passes the imager. The imager is movable to be positioned at a predetermined image capture location, and The imager is a line scanning imager, which has multiple image sensors arranged in rows along a scanning direction perpendicular to the cross scanning direction. The printhead assembly also includes a plurality of printheads, each printhead having a plurality of printhead markings at predetermined positions relative to the plurality of dispensing nozzles, and The printing system further includes a controller, the controller being configured to... Detect from the image captured by the imager The plurality of reference markers, and The multiple printhead markings, and Determine the positions of multiple distribution nozzles in the printhead assembly, based on The detected multiple reference markers, The detected multiple printhead marks, and The plurality of printhead markings are positioned relative to the plurality of dispensing nozzles at predetermined locations.

26. The printing system according to claim 25, characterized in that, Further includes: Controller, the controller is configured Controlling the movement of the printhead assembly and imager, Map the positions of the multiple dispensing nozzles in the printhead assembly to the corresponding positions in the reference system of the printing system, and Based on the mapped positions of the plurality of dispensing nozzles in the reference system of the printing system, the ejection of printing material from the plurality of dispensing nozzles is controlled.

27. The printing system according to claim 26, characterized in that, The controller is configured to detect the plurality of reference marks and the plurality of distribution nozzles in the image captured by the imager, and to determine the positions of the plurality of distribution nozzles in the printhead assembly based on the detected reference marks and the detected distribution nozzles.

28. The printing system according to claim 25, characterized in that, The scanning direction is the Y direction, and the cross-scanning direction is the X direction.

29. A printing system, characterized in that, include: Substrate support; A printhead assembly positioned facing the substrate support, the printhead assembly comprising: Multiple dispensing nozzles extending toward the substrate support in the spraying direction; as well as Multiple tags; and An imager, oriented in a direction opposite to the direction of the jet, is used to capture an image comprising multiple markers, wherein The printhead assembly is movable relative to the imager and the substrate support in the cross-scanning direction and is positioned to place the dispensing nozzle and the marker within the imager's image field, enabling the imager to capture the image as the printhead assembly passes through the imager. The imager is a line scanning imager, which has multiple image sensors arranged in rows along a scanning direction perpendicular to the cross scanning direction. The printhead assembly also includes a plurality of printheads, each printhead having a plurality of printhead markings at predetermined positions relative to the plurality of dispensing nozzles, and The printing system further includes a controller, the controller being configured to... Detect from the image captured by the imager The plurality of markers, and The multiple printhead markings, and Determine the positions of multiple distribution nozzles in the printhead assembly, based on The detected multiple markers, The detected multiple printhead marks, and The plurality of printhead markings are positioned relative to the plurality of dispensing nozzles at predetermined locations.

30. The printing system according to claim 29, characterized in that, Further including Controller, the controller is configured Mapping the positions of the multiple distribution nozzles in the printhead assembly to the corresponding positions in the reference system of the printing system, and Based on the mapped positions of the plurality of dispensing nozzles in the reference system of the printing system, the ejection of printing material from the plurality of dispensing nozzles is controlled.

31. The printing system according to claim 29, characterized in that... The controller is set to Detect from the image captured by the imager The plurality of markers, and The distribution nozzle among the plurality of distribution nozzles, and Determine the positions of the multiple dispensing nozzles in the printhead assembly, based on The detected multiple markers, and Detected dispensing nozzles.

32. The printing system according to claim 29, characterized in that... The imager is fixed to the substrate support.

33. The printing system according to claim 32, characterized in that... The plurality of dispensing nozzles are arranged in at least one row along the cross-scanning direction.

34. The printing system according to claim 33, characterized in that, Further includes: A controller configured to control the line scanning imager to capture images including all of the plurality of assigned nozzles in a single pass of the printhead assembly along the cross-scanning direction by the line scanning imager.

35. The printing system according to claim 29, characterized in that... The imager can move relative to the substrate support in a swinging motion.

36. The printing system according to claim 29, characterized in that... The scanning direction is the Y direction, and the cross-scanning direction is the X direction.

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