Printhead Alignment

Abstract

A printhead assembly for an inkjet printer is disclosed. [Solution] The printhead assembly includes a printhead having a plurality of nozzles, a nozzle plate attached to the printhead, and a base plate attached to the nozzle plate by at least three fasteners. The at least three fasteners position the nozzle plate relative to the base plate independently in each of three dimensions of a Cartesian coordinate system. The printhead assembly has a fluid connection between the printhead and a fluid manifold. The fluid manifold has alignment features. The printhead assembly further includes a tiling structure coupled to the base plate. The tiling structure has a first portion and a second portion, the first portion being resiliently coupled to the second portion.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 265,807, filed December 21, 2021, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Industrial inkjet printers are used to apply materials to large substrates to form various devices. The substrates can be hard or soft, thick or thin, and made of a variety of materials. The most typical types of substrates used in this way include substrates made of various types of glass, which are processed to produce electronic displays such as televisions and displays for smartphones.

[0003] Inkjet printers use printheads with nozzles that eject and deposit printing material onto a substrate. Today's industrial inkjet printers deposit tiny droplets of printing material onto a substrate with great precision to create precisely placed, tiny or ultra-fine structures. To increase production speed, it is common to use multiple printheads to perform a single print job. Modern inkjet printing is so precise that it is useful to precisely align the printheads to ensure that the print droplets land where they are desired. As print droplet sizes decrease to as small as 10 μm, the need for printhead alignment increases.

[0004] In industrial-scale inkjet printers, printheads may need to be replaced. Today's printheads are typically packaged in sets, with several printheads per cartridge. A given printer may require multiple printhead cartridges for a given printhead assembly. To minimize printer downtime when replacing printheads and cartridges, it is useful to be able to quickly remove and install the printhead cartridge while maintaining good contact with the ink supply and electrical components. It is also useful for all cartridges to be aligned with each other.

[0005] Additionally, as an inkjet printer operates, the temperature of the printer components typically changes. These temperature changes can cause the alignment and placement of nozzles in the printhead and cartridge to change. When these changes occur, it is often necessary to recalibrate the printer based on the new nozzle positions, which can vary by a few microns depending on the operating temperature range. For example, a printhead may be installed and aligned in a print cartridge, and multiple cartridges may be assembled to create a printhead assembly, all at room temperature. If the printhead assembly heats up during production, the alignment of all the printheads and nozzles may change. Detecting and responding to these changes requires time-consuming calibration procedures, slowing down production. If these changes can be managed and minimized, production speeds can be increased.

[0006] There is a continuing need for methods and apparatus for achieving, maintaining and controlling highly accurate alignment of printheads for industrial scale ink jet printers. Summary of the Invention

[0007] According to embodiments described herein, there is provided a printhead assembly for an inkjet printer comprising: a printhead having a plurality of nozzles; a nozzle plate attached to the printhead; and a base plate attached to the nozzle plate by at least three fasteners, the at least three fasteners positioning the nozzle plate relative to the base plate independently in each of three dimensions.

[0008] According to other embodiments described herein, there is provided a printhead assembly for an inkjet printer comprising: a support plate; a feeder plate including a plurality of alignment features; and a plurality of printing tiles disposed between the support plate and the feeder plate, each of the plurality of printing tiles comprising a plurality of printheads, each printhead having a plurality of nozzles; a nozzle plate attached to each of the plurality of printheads; a base plate attached to the nozzle plate by at least three fasteners that position the nozzle plate relative to the base plate independently in each of three dimensions; and a fluid manifold including at least one alignment feature that coincides with one of the alignment features of the feeder plate. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 2 is a plan view of a printhead group according to one embodiment.

[0010] [Figure 1B] FIG. 1B is an elevational view of a portion of the printhead group of FIG. 1A.

[0011] [Figure 2A] 1 is a schematic side view of a tile component for use in an industrial-scale inkjet printer according to one embodiment; FIG.

[0012] [Figure 2B]FIG. 2B is a schematic top view of the tile part of FIG. 2A.

[0013] [Figure 3A] FIG. 2 is a schematic, partially exploded side view of a printing tile according to one embodiment.

[0014] [Figure 3B] FIG. 3B is a top view of the assembled printing tiles of FIG. 3A.

[0015] [Figure 3C] FIG. 3C is a detailed view of a portion of the printing tile of FIGS. 3A and 3B according to one embodiment.

[0016] [Figure 4] FIG. 2 is a schematic elevation view showing the printhead assembly partially assembled with printing tiles partially inserted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1A is a plan view of a printhead group 100 according to one embodiment. The printhead group 100 includes a plurality of printheads 102 (in this example, three printheads 102), each having a plurality of print nozzles for ejecting printing material. For simplicity, the nozzles are not shown. Each printhead 102 is attached to a nozzle plate 104. Each nozzle plate 104 is attached to a base plate 106. The base plate 106 serves to bundle the plurality of nozzle plates 104 and the plurality of printheads 102 together to form the printhead group 100.

[0018] Each nozzle plate 104 is attached to the base plate by three fasteners. These fasteners position the nozzle plate relative to the base plate independently in each of the three dimensions. Each nozzle plate 104 has a longitudinal dimension 110, a transverse dimension 112, a first end 114, and a second end 116 located opposite the first end 114 along the longitudinal dimension 110. A first fastener 118 is located at the first end 114 on a central axis of the nozzle plate in the direction of the longitudinal dimension 110. The first fastener 118 is operable to position the nozzle plate 104 along its longitudinal dimension 110. The first end 114 is formed with a notch 120 that is symmetrical with respect to the longitudinal dimension 110. In this example, two straight sides of the notch 120 meet at a point located on the central axis of the nozzle plate 104 extending along the longitudinal dimension 110. The first fastener 118 exerts a positioning force at the first end 114 by exerting equal force on both sides of the notch 120. The forces cancel each other in the short direction and add in the long direction. This allows the nozzle plate 104 to be positioned in the long dimension 110 by manipulation of the first fastener 118. The base plate has a low coefficient of thermal expansion to ensure dimensional stability in order to maintain the relative positions of the printheads and other components of the printhead cluster 100. In one example, the base plate has a coefficient of thermal expansion of approximately 20×10 -6 / K.

[0019] 1B is a schematic elevational view of a portion of the printhead group 100. In this figure, an example of a fastener 150 that can be used to position the nozzle plate 104 as described above is shown along with a portion of the nozzle plate 104. The fastener 150 is a conical screw having a conical head 152 with a beveled edge 154. The fastener 150 is positioned so that the conical head 152 abuts against the nozzle plate 104. When the conical screw 150 is operated, the abutment point between the nozzle plate 104 and the conical head 152 changes. When the conical screw 150 advances, the abutment point moves to a position on the larger diameter side of the conical head 152, resulting in a force that urges the nozzle plate 104 in a direction away from the conical screw 150. When the conical screw 150 retracts, the abutment point between the conical head 152 and the nozzle plate 104 moves to a position on the smaller diameter side, resulting in a decrease in the force applied by the conical screw 150 to the nozzle plate 104. As the balance of forces on the nozzle plate 104 changes, the reaction force on the nozzle plate 104 urges the nozzle plate 104 towards the conical screw 150. In this manner, the conical screw can be used as a fastener that can position the nozzle plate in the longitudinal dimension 110.

[0020] 1A, the notch 120 can have any shape that is symmetrical about the longitudinal dimension 110. The shape can also be polygonal, circular, or irregular.

[0021] The second fastener 122 is located at the second end 116 and is operable to position the nozzle plate 104 in the direction of its short dimension 112. The second fastener 122 is disposed near the second end 116 along a side 124 of the nozzle plate 104. In this example, because the second fastener 122 is disposed near the second end 116 along the side 124 of the nozzle plate 104, the nozzle plate 104 can be rotated about its vertical axis by manipulating the second fastener 122. That is, the nozzle plate 104 can be rotated about an axis perpendicular to a plane defined by its long dimension 110 and short dimension 112 (a plane substantially parallel to the base plate 106) by manipulating the second fastener 122.

[0022] When the second fastener 122 is actuated, the second end 116 moves in the direction of the short dimension 112 while the first end 114 rotates about the first fastener 118. If the first fastener 118 is not actuated at the same time, the first fastener 118 maintains the position of the nozzle plate 104 in the long dimension 110 and maintains the position of the first end 114. Meanwhile, the second fastener 122 changes the position of the second end 116. As a result, the nozzle plate 104 rotates about the fixed position of the first fastener 118. Because the second fastener 122 moves the nozzle plate 104 a short distance, the second fastener 122 effectively moves the nozzle plate 104 quasi-linearly (i.e., differentially non-parallel) approximately parallel to the short dimension 112. Also, the second fastener 122 can be actuated to align the nozzle plate 104 with any desired feature or orientation. In particular, the nozzle plates 104 can be aligned relative to one another by manipulating the second fasteners 122 of each nozzle plate 104, and therefore all of the nozzle plates 104 of the printhead group 100 can be aligned. The first fasteners 118 of each nozzle plate 104 can be aligned in each of two dimensions that define a plane generally parallel to the plane of the base plate 106.

[0023] By providing the opposing member 130, it is possible to provide a restoring force in the direction of the longitudinal dimension 110. The opposing member 130 is located at the second end 116 of the nozzle plate 104 and abuts against the second end 116. The opposing member 130 is an elastic member configured to apply a force to the nozzle plate in a direction substantially opposite to the direction of the force applied by the first fastener 118. When the first fastener 118 is operated to press the nozzle plate 104 toward the opposing member 130 (in a direction away from the first fastener 118), the opposing member 130 is depressed, and the nozzle plate 104 moves in a direction away from the first fastener 118. When the nozzle plate 104 moves in a direction away from the first fastener 118, the opposing member 130 accumulates potential energy due to the restoring force. When the first fastener 118 is operated to move the nozzle plate 104 toward the first fastener 118, the potential energy due to the restoring force stored in the opposing member 130 is released, and the nozzle plate 104 moves toward the first fastener 118.

[0024] In some cases, the print head group 100 may be provided with a second opposing member 132 located on the opposite side of the second fastener 122, with the opposing member 130 as the first opposing member. The second opposing member 132 provides a restoring force similar to that described above. That is, when the second fastener 122 is operated to rotate the nozzle plate 104 toward the second fastener 122, the restoring force moves the nozzle plate 104 toward the second fastener 122. The first opposing member 130 and the second opposing member 132 may be spring members such as leaf springs or coil springs, or other elastic members (e.g., homogeneous compressible members such as rubber stops).

[0025] It should be noted that the opposing members 130, 132 help manage the effects of thermal expansion during temperature cycling. As the temperature of the printhead cluster 100 changes, the thermal expansion of the printhead cluster 100 components changes the dimensions and relative positions of the components. Because the components are nearly identical in composition and close in relative positions, the thermal response of similar components (e.g., all of the nozzle plates 104) is nearly identical. For example, the dimensions of the nozzle plate 104 increase as the temperature increases. Because the positions of the various fasteners that abut the nozzle plate 104 do not change, the thermal expansion increases the forces on the opposing members 130, 132, causing them to dent. Then, as the temperature decreases during cycling, the opposing members 130, 132 relax as the nozzle plate 104 shrinks in dimensions. This allows substantially all of the nozzle plates 104 to remain aligned throughout the temperature cycle.

[0026] The provision of the third fasteners 140 allows the nozzle plates 104 to be adjusted in a third direction different from the directions of the long dimension 110 and the short dimension 112. In this example, one or more spacers 142 are used in conjunction with the third fasteners 140 of the nozzle plates 104 to adjust the position of each nozzle plate 104 in the third direction. In this example, two fasteners 140 are used to position the nozzle plate 104 in the third direction, one at the first end 114 and the other at the second end 116. The two fasteners 140 are independently operable with their respective spacers 142. This allows for further height adjustment of the nozzle plate 104 and the attached print head 102. The spacers 142 are located between the nozzle plate 104 and the base plate 106 and are located substantially below the area where the force of the third fasteners 140 is applied. This allows the nozzle plate 104 to be positioned in a desired position in the third direction in the vicinity of the third fasteners 140. The thickness of the spacers 142 can be set to any desired thickness that allows the nozzle plate 104 to be parametrically positioned in the third direction. In one example, the thickness of each spacer 142 is 25 μm, but is not limited thereto. The spacers 142 protrude substantially outward between the nozzle plate 104 and the base plate 106. This allows the spacers 142 to be easily operated. Note that, depending on the need for adjusting the position and angle of the nozzle plate 104 in the third direction, two or more spacers 142 may be provided at one location, or there may be a location where no spacer 142 is provided.

[0027] The nozzle plates 104 can be aligned in any order in the three directions with the printheads 102 attached. In one example process, the nozzle plates 104 are loosely attached to the base plate 106. A first nozzle plate 104 of the printhead group 100 is mounted in a fixed position with respect to the longitudinal dimension 110 using fixed position fasteners 144 in the notches 120. The other nozzle plates 104 with the printheads 102 attached are aligned with the first nozzle plate 104 using first fasteners 118 at their corresponding first ends 114. The second fasteners 122 of all the nozzle plates 104 are manipulated to align all the nozzle plates 104. For example, the second fasteners 122 of all the nozzle plates 104 may be used to align all the nozzle plates 104 to a reference position (e.g., an edge of the base plate 106). Next, the third fastener 140 is operated together with the spacer 142 to align and adjust the height of the nozzle plate 104 in the third direction. The base plate 106 is provided with four recesses 146 for receiving the supports of a tile structure, which will be described later. The recesses 146 allow the printhead group 100 to be integrated with the printing tiles. The printing tiles supply printing fluid to the printhead group 100 and control the operation of the printhead group 100.

[0028] The printhead cluster 100 is fitted with printing fluid conduits for supplying printing fluid to the printheads 102. FIG. 2A is a schematic side view of a tile component 200 for use in an industrial-scale inkjet printer according to one embodiment. In this side view, the printhead cluster 100 that the tile component 200 comprises is shown with one printhead 102, one nozzle plate 104, and a set of first fasteners 118, second fasteners 122, and third fasteners 140. A supply conduit 202 is fitted to the nozzle plate 104 adjacent a first side 204 of the printhead 102. A return conduit 206 is fitted to the nozzle plate 104 adjacent a second side 208 of the printhead 102. The supply conduit 202 delivers printing fluid to the printhead 102. The return conduit 206 returns printing fluid from the printhead 102. Thus, the tile component 200 is a fluid component that may be used as part of a printing tile (not shown in FIG. 2A) for an inkjet printer. The supply conduit 202 and the return conduit 206 may be swapped from the example shown in FIG. 2A. That is, the supply conduit 202 may be mounted adjacent the second side 208 and the return conduit 206 may be mounted adjacent the first side 204.

[0029] The supply conduits 202 and return conduits 206 are also attached to a fluid manifold 210, which is used to fluidly connect the tile component 200 to a printing supply system (not shown). FIG. 2B is a schematic top view of the tile component 200. The fluid manifold 210 has a fluid supply port 212 and a fluid return port 214 at positions that engage the supply conduits 202 and return conduits 206 (FIG. 2A). The fluid supply port 212 and the fluid return port 214 each have a sealing surface 215 that seals when a respective fluid nozzle of the printing supply system is inserted therein. Each fluid nozzle of the printing supply system has a shoulder that contacts the sealing surface 215 with a sealing pressure when a fluid connection is made with the fluid supply port 212 and the fluid return port 214. This seals the connection between the fluid ports 212, 214 and the printing supply system.

[0030] The fluid manifold 210 has two alignment features 216 that aid in the mounting of a printing tile that includes the tile part 200 as a component. Printing tiles are described in more detail below. The alignment features 216 are located between the fluid supply port 212 and the fluid return port 214, and in this example are slightly offset from a line connecting the centers of the fluid supply port 212 and the fluid return port 214. The alignment features 216 can be provided at any suitable location on the fluid manifold 210. The alignment features 216 can be protruding or recessed. In this example, the alignment features 216 are recessed to receive alignment protruding portions for aligning the fluid manifold 210 with a fluid supply component (not shown in FIG. 2B) of a printing supply system. Each alignment feature 216 has an inlet 217 that is angled. When a printing tile including a tile part 200 with alignment features 216 is inserted and engaged into a print delivery system, alignment protrusions for alignment of the print delivery system fit into the alignment features 216. This allows the printing tile to be easily aligned while it is being installed, as described in more detail below.

[0031] The fluid manifold 210 has an engagement feature 218 for fixing the printing tile including the tile part 200 to the printing supply system. In this example, the engagement feature 218 is a screw recess for receiving a screw. By manipulating the screw, the printing tile and the printing supply system can be securely engaged. The outer wall 220 of the fluid manifold 210 defines an inner surface 222 of the fluid manifold 210. The outer wall 220 is higher than the inner surface 222. This allows for the retention of fluid when the tile part 200 is disengaged from the printing supply system, for example, when the fluid contained in the printing supply system or the supply conduit 202 and the return conduit 206 leaks during removal of the printing tile. The engagement feature 218 is provided on a plateau 224. The height of the plateau 224 is approximately equal to the height of the outer wall 220 to prevent the ingress of fluid into the engagement feature 218. In this example, the ingress of fluid into the engagement feature 218 is undesirable. This is because the fluid manifold 210 is provided with sensors that detect engagement of the threads with the engagement features 218 to ensure a secure fit of the printing tile. The pedestals 224 may be higher than the outer wall 220, or in some cases may be slightly lower than the outer wall 220. If the pedestals 224 are too low, printing fluid may get into the engagement features 218 when the printing tile is disengaged from the print delivery system.

[0032] Referring again to FIG. 2A, an optical sensor 226 is attached to the underside 228 of the fluid manifold 210 to detect engagement of the screw with the engagement feature 218. The sensor 226 may be attached directly to the fluid manifold 210 or via an intermediate member such as a metal plate (not shown). When fully engaged, the screw extends to the optical sensor 226 and covers the light path of the light source in the optical sensor. A photodetector in the optical sensor detects the presence or absence of light from the light source and outputs a signal accordingly. If there is light, the photodetector signals that the screw is not fully engaged. If there is no light, the photodetector signals that the screw is fully engaged. In this manner, a user can easily verify that the print tile is fully engaged in the print delivery system.

[0033] Other types of sensors can be used to detect engagement, for example, an optical sensor can be located within the fluid manifold 210 rather than attached to the underside 228. Also, a conductivity sensor can be used to detect contact between the threads and the engagement features if both the threads and the engagement features include conductive elements.

[0034] The tile parts 200 are assembled with electrical components to form a printing tile. Figure 3A is a schematic side view, partially exploded, of a printing tile 300 according to one embodiment. The tile part 200 is shown on the right side of the figure. The supply conduits 202 are shown in this view, but the return conduits 206 are hidden. The supply conduits 202 are fluidly coupled to the printheads 102 via supply tubes 350 for each printhead 102. The supply tubes 350 are coupled to the supply conduits 202 via a supply tube manifold 352. On the opposite side of each printhead 102, the return conduits are coupled to the printheads 102 by similar return tubes and return tube manifolds.

[0035] An electrical component 302, shown on the left side of the figure, is assembled with the tile component 200 to form the printing tile 300. The electrical component 302 comprises a tile structure 304 that supports a control box 306 and an interface circuit 308. The interface circuit 308 is implemented as a circuit board in this example. The interface circuit 308 is electrically connected to the control box 306 by wiring. The control box 306 contains circuitry that controls the operation of the printhead 102. When the electrical component 302 is assembled with the tile component 200, the control box 306 is connected to the printhead 102 by wiring.

[0036] The tile structure 304 has a first portion 310 that supports the interface circuit 308. The first portion 310 aligns and supports the interface circuit 308 and the fluid manifold 210. This allows the printing tile 300 to be quickly and easily connected to a print delivery system, as described in more detail below. The first portion 310 has a first plate 312 and a second plate 314 connected by four upper support posts 316 (two are shown in FIG. 3A). The first plate 312 and the second plate 314 are generally parallel. The four upper support posts 316 are generally parallel to each other and generally perpendicular to the first plate 312 and the second plate 314. The interface circuit 308 is supported by an interface support plate 318. The interface support plate 318 extends from the first plate 312 into the first portion 310 in a direction generally perpendicular to the first plate 312. The interface circuit 308 is attached to the interface support plate 318 using mounting spacers 320. The mounting spacers 320 precisely position the interface circuit 308 relative to the interface support plate 318, facilitating electrical connection with the print delivery system.

[0037] The second plate 314 of the first portion 310 is attached to a second portion 322 of the tile structure 304. The second portion 322 includes a mounting plate 324 to which the second plate 314 is attached. The second plate 314 and the mounting plate 324 are fastened together using resilient fasteners 326. The resilient fasteners 326 are resilient and allow the first portion 310 and the second portion 322 to move out of alignment with each other. The resilience of the resilient fasteners 326 allows the first portion 310 and the second portion 322 to move out of alignment slightly with each other, facilitating connection to a print delivery system, while still firmly fastening the first portion 310 and the second portion 322 together. In one embodiment, the resilient fasteners 326 are spring loaded shoulder screws, although any resilient fastener may be used.

[0038] FIG. 3C is a detailed view of a portion of the electrical component 302 according to one embodiment, illustrating how the first portion 310 is attached to the second portion 322. The resilient fastener 326 is a spring-loaded shoulder screw with a spring 325. The spring 325 is disposed between the mounting plate 324 and the second plate 314 and is compressed by a screw 327. In this manner, the first portion 310 can be resiliently lifted up via the spring 325 when the first portion 310 is attached to the second portion 322. In other embodiments, the spring 325 can be in tension by holding the plate 314 and the plate 324 apart from each other with the screw 327. Other resilient fasteners can be used.

[0039] 3A, the second portion 322 has four lower support posts 329. The lower support posts 329 extend from the mounting plate 324 and define an outer perimeter of the second portion 322 that is generally equal to the outer perimeter of the first portion 310 defined by the upper support posts 316 in this example. The lower support posts 329 fit into recesses 146 (FIG. 1A) in the base plate 106 of the printhead group 100, thereby integrating the electrical component 302 with the tile component 200. This results in a printing tile 300 that can be handled as a unit.

[0040] The second section 322 further includes a control box 306 that is attached to four lower posts 329. The mounting plate 324 also supports the control box 306 and provides rigidity to the second section 322 and to the printing tile 300 when the electrical components 302 are assembled to the tile component 200.

[0041] 3B is a top view of an assembled printing tile 300. In this view, the first plate 312 is shown with the connecting edges 328 of the fluid manifold 210 and interface circuit 308 positioned to connect with a print delivery system. The first plate 312 is attached with a window 330 by fasteners 332. The window 330 allows for lateral support and positioning of the fluid manifold 210 when the tile 300 is assembled. The first plate 312 is also provided with an opening 334 for receiving or, optionally, allowing the connecting edge 328 to pass through, thereby allowing connection with the print delivery system. The opening 334 has a clearance around the connecting edge 328 to allow the connecting edge 328 to engage with a connection portion of the print delivery system.

[0042] The first plate 312 has an orientation feature 336 to ensure that the printing tile 300 is properly oriented and mounted. The printing tile 300 is mounted within a printhead assembly (not shown). The printhead assembly supports the printing tile 300 and, in operation, positions the printing tile 300 for printing. The printhead assembly also includes a print feed system with which the printing tile 300 engages. The printhead assembly includes a corresponding orientation feature to ensure that the printing tile 300 is properly mounted. Here, the orientation feature 336 is a protrusion that protrudes laterally from an edge of the first plate 312. In this example, the orientation feature 336 protrudes from a long edge of the first plate 312, which is generally rectangular. It is noted that the first plate 312 may have any suitable shape and the orientation feature 336 may be located at any suitable position on the first plate 312. Here, the orientation feature 336 is semicircular, but the orientation feature 336 may have any suitable shape. Alternatively, the orientation features may be recessed instead of protruding. Any number of orientation features may be used. In the illustrated example, there is one orientation feature 336.

[0043] 4 is a schematic elevational view of a printhead assembly 400 with a printing tile partially inserted and partially assembled. The printhead assembly 400 includes a support plate 402 and a feed plate 404. A print feed system 406 is provided on a first side of the feed plate 404 and is connected to the printing tiles 300 via the feed plate 404. The support plate 402 supports the inserted and connected printing tiles 300. A number of printing tiles 300 are inserted to form the printhead assembly 400.

[0044] The printing tile 300 is inserted from the support plate 402 and advances toward the supply plate 404 until it is connected to the print supply system 406. A guide portion is provided to guide the printing tile 300 so that it is inserted from the support plate 402 to the supply plate 404. A first guide portion 408 is attached to the surface of the support plate 402 facing the supply plate 404 so as to extend toward the supply plate 404. Here, the first guide portion 408 is a plate-like structure, but in another example, the first guide portion 408 may be a pair of rails. In that case, the corresponding rails guide both side surfaces of the printing tile 300, respectively. Typically, at least two first guide portions 408 are provided on both side surfaces of the printing tile 300 (only one first guide portion 408 is shown in this figure). In some cases, a total of four first guide portions 408 may be provided, one on each side surface of the rectangular parallelepiped printing tile 300. The first guide portion 408 is formed to roughly match the shape of the printing tile 300. Here, since the print tile 300 is a rectangular parallelepiped, the first guide portion 408 is formed in a plate shape that fits along the side of the rectangular parallelepiped print tile 300. In another example, the print tile 300 may have another shape. When the print tile 300 is substantially polyhedral in shape, the first guide portion 408 may be a plate shape that can be guided along the side of the print tile 300, or a rail shape that can be guided along the edge of the print tile 300. When the print tile 300 has a curved side, the first guide portion 408 may be curved accordingly. The first guide portion 408 may be composed of a plurality of separate plates, or may be a single box-shaped structure that surrounds the insertion path of the print tile 300. The first guide portion 408 may also be a partially discontinuous plate-shaped structure. For example, it may be a structure in which two guide rails are connected by one or more bars or rods. The first guide portion 408 may also be a partially discontinuous box-shaped structure. For example, it may be a structure in which four guide rails extending from the support plate 402 toward the supply plate 404 are connected in a rectangular shape by a bar or rod. The first guide portion 408 maintains the printing tile 300 in a substantially straight orientation when the printing tile 300 is inserted from the support plate 402 toward the supply plate 404.

[0045] A second guide unit 410 is attached to the surface of the supply plate 404 facing the support plate 402 so as to extend toward the support plate 402. The second guide unit 410 has a number of plate-like structures 411, each having an inclined cross section. The plate-like structures 411 guide the printing tiles 300 so that the printing tiles 300 are aligned with various connection features of the supply plate 404 and the printing supply system 406. In this example, the second guide unit 410 is a single member attached to the surface of the supply plate 404 facing the support plate 402, and the plate-like structures 411 extend toward the support plate 402. Three of the plate-like structures 411 of the second guide unit 410 are shown in FIG. 4. The second guide unit 410 has four plate-like structures 411, but in FIG. 4, the frontmost plate-like structure 411 is omitted in order to show in detail the relationship between the printing tiles 300, the supply plate 404, and the printing supply system 406.

[0046] Each of the plate-like structures 411 has an inner surface 412 facing inward toward the printing tile 300. As the inner surface 412 of each plate-like structure 411 moves away from the supply plate 404, the inner surface 412 slopes away from the printing tile 300. In other words, each plate-like structure 411 has a wide end 413 on the supply plate 404 side and a narrow end 415 opposite the wide end 413. As the printing tile 300 advances toward the supply plate 404, the positional freedom of the printing tile 300 narrows toward the wide end 413 of the plate-like structure 411 due to the inclination of the inner surface 412 of the plate-like structure 411. This allows the printing tile 300 to be guided to a position where the connecting edge 328 (FIG. 3B) of the fluid manifold 210 and the interface circuit 308 connects with the fluidic and electrical features of the printing supply system 406.

[0047] The supply plate 404 has two alignment protrusions 414 that engage with the alignment features 216 (FIG. 2B). The alignment protrusions 414 (in this example, convex) have sharp tips. This allows the alignment protrusions 414 to engage the alignment features 216 (FIG. 2B) of the fluid manifold 210 reliably as the printing tile 300 advances to engage with the printing supply system 406. As mentioned above, other types of alignment features can be used. The presence of the second guide 410, the engagement of the alignment protrusions 414 with the alignment features 216, and the resiliently attached first portion 310 to the second portion 322 passively close the tolerances to guide the printing tile 300 toward the fluid and electrical connections of the printing supply system 406. This allows the engagement features 218 (FIG. 2B) to contact the engagement screws 416 that pass through the supply plate 404. Additionally, the fluid ports 212, 214 (FIG. 2B) of the fluid manifold 210 and the connecting edge 328 of the interface circuit 308 generally interface with corresponding features in the print delivery system 406. The engagement screw 416 is captured within the feed plate 406 such that manipulation of the engagement screw 416 biases the printing tile 300 into reliable fluid and electrical contact with the print delivery system 406. The various alignment features in the fluid manifold 210, the precise positioning of the interface circuit 308 on the printing tile 300, and the first and second guides 408, 410 allow the printing tile 300 to be quickly and easily inserted into the printhead assembly 400 and connected to the print delivery system 406. The above-described shape, size, and tolerances of the second guide portion 410, the alignment protrusion 414, and the alignment feature 216, as well as the resiliently connected first portion 310 and second portion 322 of the tile structure 304, ensure that the printing tile 300 is aligned when inserted into the print head assembly 400.

[0048] When the printing supply system 406 is connected, the fluid nozzles (not shown) of the printing supply system 406 are fluidly connected and sealed to the fluid ports 212, 214 of the fluid manifold 210. This fluidly connects the fluid ports 212, 214 to a fluid supply return conduit 420 in the printing supply system 406, which is located on the opposite side of the supply plate 404 from the fluid manifold 210. Fluid valves 422 are provided to control the flow of fluid from the printing supply system 406 to the fluid manifold 210 and the printing tiles 300 and vice versa. As described above, the printhead assembly 400 includes a plurality of printing tiles 300, each of which is connected to the printing supply system 406 in the same manner. A pair of fluid valves 422 are provided for each printing tile 300 and are operated by a control system. This controls the flow of fluid between each printing tile 300 and a fluid reservoir of the printhead assembly 400. It is also possible to use more than one type of printing fluid in such a printhead assembly, with each type of fluid being delivered to a separate group of printing tiles 300 using dedicated fluid supply and return conduits.

[0049] While embodiments in accordance with one or more aspects of the present invention have been described above, other embodiments not specifically described in this disclosure may be devised without departing from the basic scope of the disclosure, which scope is defined by the following claims.

Claims

1. 1. A printhead assembly for an inkjet printer, comprising: a print head having a plurality of nozzles; a nozzle plate attached to the printhead; and a base plate attached to the nozzle plate by at least three fasteners, the at least three fasteners positioning the nozzle plate relative to the base plate independently in each of an X-axis direction, a Y-axis direction, and a Z-axis direction.

2. The printhead assembly of claim 1 , wherein at least one of the fasteners includes a shim.

3. The printhead assembly of claim 1 , wherein at least one of the fasteners is a conical screw.

4. The printhead assembly of claim 3 , wherein the at least one conical screw is positioned to allow for adjustable rotation of the nozzle plate relative to the base plate.

5. 5. The printhead assembly of claim 4, wherein the at least one conical screw includes a first conical screw arranged to allow rotation of the nozzle plate relative to the base plate, and a second conical screw arranged to allow linear movement of the nozzle plate relative to the base plate.

6. the nozzle plate has a longitudinal dimension, a transverse dimension, a first end, and a second end opposite the first end along the longitudinal dimension; the first conical thread is located at the first end; The printhead assembly of claim 5 , wherein the second conical thread is located at the second end along a side of the nozzle plate.

7. The thermal expansion coefficient of the base plate is about 20×10 －６ 2. The printhead assembly of claim 1, wherein the .lambda. / K is less than .lambda. / K.

8. the print head is a first print head; the nozzle plate is a first nozzle plate, The printhead assembly further includes a second printhead attached to a second nozzle plate; 2. The printhead assembly of claim 1, wherein the second nozzle plate is attached to a base plate by at least three fasteners that provide independent positioning of the second nozzle plate relative to the base plate in an X-axis direction and a Y-axis direction and fix a position of the second nozzle plate relative to the base plate in a Z-axis direction.

9. a tile structure having a first end attached to the base plate; a fluid manifold attached to a second end of the tile structure opposite the first end, The printhead assembly of claim 1 , wherein the fluid manifold comprises at least two fluid connections and at least two manifold alignment features.

10. further comprising an electrical component attached to the tile structure; 10. The printhead assembly of claim 9, wherein the electrical component has a connecting member disposed within a notch in the fluid manifold.

11. The printhead assembly of claim 9 , wherein the fluid manifold has a wall surrounding the fluid connection.

12. The printhead assembly of claim 9 , wherein the fluid manifold has recesses that receive manifold fasteners.

13. The printhead assembly of claim 12 , wherein the fluid manifold further comprises a sensor that detects the presence or absence of the manifold fastener.

14. The printhead assembly of claim 13 , wherein the sensor is mounted to a major surface of the fluid manifold.

15. the tile structure includes a first member attached to the base plate and a second member attached to the fluid manifold; The printhead assembly of claim 9 , wherein the first member is attached to the second member by a resilient connection.

16. The printhead assembly of claim 9 , wherein the tile structure includes an orientation feature.

17. 1. A printhead assembly for an inkjet printer, comprising: A support plate; a feed plate including a plurality of alignment protrusions; a plurality of printing tiles disposed between the support plate and the supply plate; Equipped with Each of the plurality of print tiles comprises: a plurality of printheads, each printhead having a plurality of nozzles; a nozzle plate attached to each of the plurality of printheads; a base plate attached to the nozzle plate by at least three fasteners, the at least three fasteners positioning the nozzle plate relative to the base plate independently in each of an X-axis direction, a Y-axis direction, and a Z-axis direction; a fluid manifold including at least one alignment feature that mates with one of the alignment features of the feed plate; A print head assembly comprising:

18. The printhead assembly of claim 17 , wherein the feeder plate further comprises a printing tile guide.

19. The printhead assembly of claim 17 , wherein the support plate further comprises a printing tile guide.

20. The support plate further includes a printing tile guide portion, The supply plate further includes a print tile guide.

20. The printhead assembly of claim 17, wherein the printing tile comprises a tile structure including a first portion and a second portion, the first portion resiliently coupled to the second portion, and the second portion coupled to the base plate.

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