Flow-through printhead

Abstract

A printhead that ejects printing fluid. In an embodiment, the flow-through printhead includes a plurality of ejection channels arranged in a first row and a second row substantially parallel along a length of the printhead, where each ejection channel includes a diaphragm, a pressure chamber, and a nozzle configured to eject printing fluid. The flow-through printhead also includes a first manifold fluidically coupled to the ejection channels in the first row, and a second manifold fluidically coupled to the ejection channels in the first row. The first manifold and the second manifold are disposed on opposite sides of the first row, with the second manifold disposed in a middle region between the first row and the second row.

Description

Technical Field

[0001] The following disclosure relates to the field of image forming, and in particular to the design of printheads and / or printheads. Background Technology

[0002] Image formation is the process of reconstructing a digital image (e.g., a 2D image, a 3D image, or a model) by propelling droplets of ink or another type of printing fluid onto a medium such as paper, plastic, or a substrate for 3D printing. Image formation is commonly used in devices such as printers (e.g., inkjet printers, 3D printers, etc.), fax machines, copiers, plotters, multifunction peripherals, etc. At the heart of a typical jetting or image forming apparatus is one or more liquid droplet nozzles (often referred to here as "printheads"), which have: nozzles for discharging liquid droplets; mechanisms for moving the printhead and / or the medium relative to each other; and a controller that controls how the liquid is discharged from the individual nozzles of the printhead onto the medium in the form of pixels.

[0003] A typical printhead includes multiple nozzles arranged in one or more rows along the ejection surface of the printhead. Each nozzle is part of an "ejection channel," which includes a nozzle, a pressure chamber, and a diaphragm that vibrates in response to an actuator (e.g., a piezoelectric actuator). The printhead also includes driver circuitry that controls when each individual ejection channel is activated based on image or print data. To eject from the ejection channel, the driver circuitry provides one or more ejection pulses to the actuator, which causes the actuator to deform the walls of the pressure chamber (i.e., the diaphragm). The deformation of the pressure chamber generates a pressure wave within the pressure chamber, which ejects one or more droplets of printing fluid (e.g., ink) from the nozzle.

[0004] Nozzle malfunctions can occur in the printhead due to various factors, such as drying of the print fluid at the nozzle or meniscus, sedimentation of the print fluid, and the presence of air bubbles in the print fluid. These and other nozzle malfunctions can lead to poor print quality. Summary of the Invention

[0005] The embodiments described herein provide a flow-through printhead and related methods of using the printhead. In one embodiment, the flow-through printhead includes jet channels arranged in adjacent rows. The jet channels in the first row are fluidly coupled to a first manifold and a second manifold disposed on opposite sides of the first row. In other words, the second manifold is disposed between multiple rows of jet channels. Thus, the second manifold is disposed in a region between jet channels of previously unused adjacent rows of the printhead and allows printing fluid to circulate through the jet channels. One technical benefit is that the printing fluid can circulate through the jet channels to avoid drying or settling of the printing fluid within the jet channels, which provides improved jet consistency and performance. Another technical benefit is that the printhead can be constructed with less laminating material, which reduces manufacturing costs and allows for higher frequency jetting.

[0006] In one embodiment, the flow-through printhead includes a plurality of jet channels arranged generally parallel to each other along the length of the printhead in a first and second row, wherein each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet printing fluid. The flow-through printhead also includes a first manifold fluidly connected to the jet channels in the first row, and a second manifold fluidly connected to the jet channels in the first row. The first and second manifolds are located on opposite sides of the first row, with the second manifold located in an intermediate region between the first and second rows.

[0007] In one embodiment, the flow-through printhead includes a housing and a stack of plates attached to the housing, the stack forming a plurality of jet channels arranged generally parallel to each other in a first and second row along the length of the printhead. Each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet print fluid. The stack of plates forms a first manifold, longitudinally arranged and fluidly coupled to the jet channels in the first row. It also forms a second manifold, longitudinally arranged and fluidly coupled to the jet channels in the first row. The first and second manifolds are located on opposite sides of the first row, with the second manifold located in an intermediate region between the first and second rows.

[0008] In one embodiment, a method includes operating a flow-through printhead comprising a plurality of jet channels arranged generally parallel to the length of the printhead in a first row and a second row, wherein each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet print fluid. The flow-through printhead further includes a first manifold fluidly coupled to the jet channels in the first row, and a second manifold fluidly coupled to the jet channels in the first row. The first and second manifolds are disposed on opposite sides of the first row, with the second manifold disposed in an intermediate region between the first and second rows. Operating the flow-through printhead includes: for each jet channel in the first row, conveying print fluid from the first manifold on a first side of the first row to the pressure chamber; and for each jet channel in the first row, conveying unjetted print fluid from the pressure chamber to the second manifold on a second side of the first row opposite to the first side.

[0009] The above overview provides a basic understanding of some aspects of the specification. This overview is not an exhaustive summary of this specification. It is not intended to identify any key or critical elements of this specification, nor to depict any specific embodiment within the scope of this specification, or any scope of the claims. Its sole purpose is to present some concepts of the specification in a simplified form as a prelude to the more detailed description that follows. Attached Figure Description

[0010] Some embodiments of this disclosure will now be described by way of example only and with reference to the accompanying drawings. Throughout the drawings, the same reference numerals denote the same elements or elements of the same type.

[0011] Figure 1 This is a schematic diagram of the spraying device in an exemplary embodiment.

[0012] Figure 2 This is a perspective view of the printhead in an exemplary embodiment.

[0013] Figure 3 This is a perspective view of the printhead in an exemplary embodiment.

[0014] Figure 4 This is a cross-sectional view of the printhead in an exemplary embodiment.

[0015] Figures 5A-5D This is a schematic diagram of the printhead in an exemplary embodiment.

[0016] Figures 6A-6B This is a cross-sectional view of a portion of the printhead in an exemplary embodiment.

[0017] Figure 7 This is a perspective view of the injection channel in an exemplary embodiment.

[0018] Figure 8An exploded perspective view of the head component of the printhead in an exemplary embodiment is shown.

[0019] Figure 9 A cavity plate is shown in an illustrative embodiment.

[0020] Figure 10 A cavity plate in an exemplary embodiment is shown.

[0021] Figure 11 This is a cross-sectional view of a portion of the printhead in an exemplary embodiment.

[0022] Figure 12 This is a flowchart illustrating a method of operating the printhead in an illustrative embodiment.

[0023] Figure 13 This is a perspective view of an injection channel having a passive mixer within one or more channels in an illustrative embodiment.

[0024] Figures 14A-14H This is a plan view of the passive mixer within the jet channel in the illustrative embodiment.

[0025] Figure 15 A current limiter board in an exemplary embodiment is shown.

[0026] Figure 16 A cavity plate in an exemplary embodiment is shown.

[0027] Figure 17 This is a flowchart illustrating a method for operating a printhead having one or more passive mixers in an illustrative embodiment.

[0028] Figure 18 This is a perspective view of an injection channel having one or more in-cavity active mixers in an illustrative embodiment.

[0029] Figure 19 This is a perspective view of the intracavity active mixer in an illustrative embodiment.

[0030] Figure 20 This is a perspective view of an intracavity active mixer in another illustrative embodiment.

[0031] Figure 21A-21I This is a plan view of a pressure chamber having one or more in-cavity active mixers in an illustrative embodiment.

[0032] Figure 22 A cavity plate is shown in an illustrative embodiment.

[0033] Figure 23 This is a flowchart illustrating a method of operating a printhead with an in-cavity active mixer in an illustrative embodiment.

[0034] Figure 24 This is a perspective view of a jet channel having an in-channel fluid mixer in an illustrative embodiment.

[0035] Figures 25A-25D An in-channel fluid mixer is shown in an exemplary embodiment.

[0036] Figure 26 A cavity plate in an exemplary embodiment is shown.

[0037] Figure 27 A cavity plate is shown in an illustrative embodiment.

[0038] Figure 28 This is a flowchart illustrating a method for operating a printhead having an in-channel fluid mixer in an illustrative embodiment.

[0039] Figure 29 This is a cross-section of the flow-through printhead in the exemplary embodiment.

[0040] Figure 30 This is a cross-section of a non-flow-through printhead in an illustrative embodiment. Detailed Implementation

[0041] The accompanying drawings and the following description illustrate specific exemplary embodiments. Therefore, it should be understood that those skilled in the art will be able to design various configurations that, while not explicitly described or shown herein, embody the principles of the embodiments and are included within the scope of the embodiments. Furthermore, any examples described herein are intended to aid in understanding the principles of the embodiments and should be construed as not being limited to such specifically enumerated examples and conditions. Therefore, the concept of the invention is not limited to the specific embodiments or examples described below, but is defined by the claims and their equivalents.

[0042] Figure 1 This is a schematic diagram of an ejector device 100 in an exemplary embodiment. The ejector device 100 is a device or system that uses one or more printheads to eject printing fluid or marking material onto a medium. One example of the ejector device 100 is an inkjet printer (e.g., a continuous feed or dicing printer) that performs single-pass printing. Other examples of the ejector device 100 include scan-through inkjet printers (e.g., wide format printers), multifunction printers, desktop printers, industrial printers, 3D printers, etc. Typically, the ejector device 100 includes a mounting mechanism 102 that supports one or more printheads 104 relative to a medium 112. The mounting mechanism 102 may be fixed within the ejector device 100 for single-pass printing. Alternatively, the mounting mechanism 102 may be disposed on a carriage assembly that reciprocates along a scan line or sub-scan direction for multi-pass printing. The printheads 104 are configured to pass through multiple nozzles (in... Figure 1An apparatus, device, or component that ejects droplets 106 of printing fluid (e.g., ink, such as water, solvent, oil, or UV-curable ink) from nozzles of printhead 104. The droplets 106 ejected from nozzles of printhead 104 are directed to medium 112. Medium 112 includes any type of material to which ink or another printing or jetting fluid is applied via the printhead, such as paper, plastic, card blanks, clear sheets, substrates for 3D printing, fabric, etc. Typically, the nozzles of printhead 104 are arranged in one or more rows such that as printhead 104 and / or medium 112 move relative to each other, the ejection of printing fluid from the nozzles results in the formation of characters, symbols, images, object layers, etc., on medium 112. Jetting device 100 may include a media transport mechanism 114 or a media holding bed 116. Media transport mechanism 114 is configured to move medium 112 relative to printhead 104. The media holding bed 116 (e.g., a platform) is configured to support the media 112 in a fixed position while the printhead 104 moves relative to the media 112.

[0043] The jetting device 100 also includes a jetting device controller 122 that controls the overall operation of the jetting device 100. The jetting device controller 122 can be connected to a data source to receive print jobs, print data, image data, etc., and controls each printhead 104 to discharge print fluid onto the media 112. The jetting device 100 also includes one or more reservoirs 124 for print fluid or multiple types of print fluid. Although in Figure 1 It is not shown in the figure, but the reservoir 124 is fluidly connected to the printhead 104, for example, by means of a hose.

[0044] Figure 2 This is a perspective view of a printhead 104 in an exemplary embodiment. In this embodiment, the printhead 104 includes a head member 202 and electronics 204. The head member 202 is an elongated component forming an ejection channel of the printhead 104. A typical ejection channel includes a nozzle, a pressure chamber, and a diaphragm driven by an actuator (e.g., a piezoelectric actuator). The electronics 204 controls how the nozzles of the printhead 104 eject droplets in response to data signals and control signals received from another controller (e.g., ejection device controller 122). The electronics 204 includes an embedded printhead controller 206 or driver circuitry configured to drive individual ejection channels based on the data signals and control signals. Figure 2 The bottom surface of the head component 202 includes the nozzle of the jet channel and represents the discharge surface 220 of the printhead 104. Figure 2The top surface of the head member 202 (referred to as I / O surface 222) represents an input / output (I / O) portion for receiving one or more print fluids into the print head 104 and / or delivering print fluid (e.g., un-ejected fluid) out of the print head 104. I / O surface 222 includes a plurality of I / O ports 211-214. I / O ports 211-214 may include inlet I / O ports, which are openings in the head member 202 that serve as an inlet or entry point for the print fluid. I / O ports 211-214 may include outlet I / O ports, which are openings in the head member 202 that serve as an outlet or exit point for the print fluid. I / O ports 211-214 may include hose connectors, hose hooks, etc., for connection to hoses of reservoirs, cartridges, etc. The number of I / O ports 211-214 is provided as an example, as the print head 104 may include other numbers of I / O ports.

[0045] Typically, the head assembly 202 includes a housing 230 and a plate stack 232. The housing 230 is a rigid member made of stainless steel or other types of material. The housing 230 includes an inlet port 234 that provides a passage for the electronics 204 to pass through the housing 230, allowing the actuator to engage (i.e., contact) the diaphragm of the injection channel. The plate stack 232 is attached to an engagement surface (not visible) of the housing 230. The plate stack 232 (also called a laminate stack) is a series of plates fixed or joined together to form a laminate stack. The plate stack 232 may include one or more nozzle plates, one or more cavity plates, one or more flow restrictor plates, support (or bracing) plates, and diaphragm plates. The nozzle plates include a plurality of nozzles arranged in one or more rows. The cavity plates include a plurality of openings forming a pressure chamber of the injection channel. The flow restrictor plates include a plurality of openings that form a flow restrictor to fluidly connect the pressure chamber of the injection channel to the manifold. A diaphragm is a sheet of semi-flexible material that vibrates in response to actuation by an actuator (e.g., a piezoelectric actuator).

[0046] Figure 2 A specific structure of printhead 104 is shown, and it should be understood that other printhead structures with multiple jet channels are considered here.

[0047] Figure 3This is a perspective view of the printhead 104 in an exemplary embodiment. In the embodiment, the head member 202 is an assembly including a housing 230 and a plate stack 232 fixed or attached to the housing 230. The plate stack 232 is an elongated stack having a length 350 (i.e., along the x-axis) and a width 352 (i.e., along the y-axis). For the purposes of this description, the x-axis is along the length 350 of the printhead 104 and may be referred to as the x-direction, length direction, longitudinal direction, etc. The y-axis is along the width 352 of the printhead 104 and may be referred to as the y-direction, width direction, transverse direction, etc. The z-axis is along the height of the printhead 104 and may be referred to as the z-direction, height direction, etc. The plate stack 232 includes one or more nozzle plates 304 having orifices of nozzles 306 forming jet channels. Thus, the bottom surface of the nozzle plate 304 defines the discharge surface 220 of the printhead 104. The nozzles 306 in Figure 3 The diagram shows two rows of nozzles arranged longitudinally along the length 350 of the plate stack 232 and generally parallel to the longitudinal sides 312-313 of the printhead 104 / plate stack 232. The longitudinal centerline 310 of the printhead 104 / plate stack 232 is shown as the x-axis between the jet channels of adjacent rows (shown by their respective nozzles) and represents the axis of symmetry between the rows. Although in Figure 3 The image shows two rows of nozzles 306, but in other embodiments, the injection channel and its corresponding nozzles 306 may be arranged in a single row or more than two rows.

[0048] Figure 4 This is a cross-sectional view of the printhead 104 in an exemplary embodiment. Figure 4 It shows along Figure 3 The cross-section of a portion of a row of jet channels 402 in the cut plane 4-4 of the printhead 104. The jet channels 402 are structural elements within the printhead 104 configured to jet or eject printing fluid. Each jet channel 402 includes a diaphragm 410, a pressure chamber 412 (also referred to as a Helmholtz chamber), and a nozzle 306. An actuator 416 contacts the diaphragm 410 to control the ejection from the jet channel 402. The jet channels 402 may be formed in rows along the length 350 of the printhead 104 (i.e., plate stack 232), and each jet channel 402 may have, for example, […]. Figure 4 A similar structure as shown.

[0049] Figures 5A-5D This is a schematic diagram of the printhead 104 in an exemplary embodiment. Figure 5A In this context, printhead 104 can be a flow-through printhead 504, where printing fluid can circulate through jet channels 402 and their corresponding nozzles 306. Therefore, jet channels 402 themselves can be referred to as flow-through jet channels 540. Rows 501-502 of jet channels 402 in printhead 104... Figure 5A The rows are schematically shown as nozzles 306. Typically, the plurality of jet channels 402 for the printhead 104 are arranged in rows 501-502 along the longitudinal direction (i.e., along the x-axis) of the length 350 of the printhead 104 and are generally parallel to each other. The printhead 104 includes manifolds 510-511 and 514-515. A manifold is a common conduit or channel within the printhead 104 (i.e., within the housing 230 and / or the plate stack 232) that provides a common fluid path for the plurality of jet channels 402. For example, in row 501, each jet channel 402 may be fluidly coupled to manifolds 510-511. In one embodiment, manifold 510 may be referred to as a supply manifold when configured or operated to supply printing fluid to a set of jet channels 402 in row 501. For example, manifold 510 may be fluidly connected between I / O ports 211-212 to receive print fluid from an external source and may serve as a common supply conduit with the ability to supply print fluid to multiple jet channels 402. When configured or operated to receive print fluid from jet channels 402 in row 501, manifold 511 may be referred to as a return manifold. Print fluid not ejected from the nozzles 306 of jet channels 402 may be referred to herein as “unejected print fluid.” Therefore, a manifold that receives print fluid from jet channels 402 may be referred to herein as receiving unejected print fluid. Manifold 511 may serve as a common return conduit with the ability to receive unejected print fluid from multiple jet channels 402 in row 501. Manifold 511 is fluidly connected to manifold 510 via jet channels 402 in row 501 and may also be fluidly connected to manifold 510 via one or more inter-manifold fluid passages 512.

[0050] For example, in row 502, each jet channel 402 may be fluidly coupled to manifolds 514-515. In one embodiment, manifold 514 may be referred to as a supply manifold when configured or operated to supply print fluid to a set of jet channels 402 in row 502. For example, manifold 514 may be fluidly coupled between I / O ports 213-214 to receive print fluid from an external source and may serve as a common supply conduit with the capability to supply print fluid to multiple jet channels 402. When configured or operated to receive print fluid from jet channels 402 in row 502, manifold 515 may be referred to as a return manifold. Manifold 515 may serve as a common return conduit with the capability to receive un-jetted print fluid from multiple jet channels 402 in row 502. Manifold 515 is fluidly coupled to manifold 514 via jet channels 402 in row 502 and may also be fluidly coupled to manifold 514 via one or more inter-manifold fluid passages 516.

[0051] Although manifolds 510 and 514 may be referred to herein as supply manifolds, and manifolds 511 and 515 as return manifolds, the flow of printing fluid can be reversed within printhead 104. Therefore, manifolds 510 and 514 may include return manifolds, and when the flow is reversed (i.e., with...) Figure 5A When the flow is reversed (as shown in the diagram), manifolds 511 and 515 may include a supply manifold.

[0052] exist Figure 5A In this flow-through type of injection channel 540, each injection channel 402 has an independent fluid path into and out of the pressure chamber 412, which are not shared or co-located with another injection channel 402. For example, each injection channel 402 in row 501 includes the pressure chamber 412 of the manifold 510 and the injection channel 402 (see also...). Figure 4 The system includes a channel fluid passage 520 (also called a channel fluid conduit) between the injection channel 402 and the manifold 511, and also includes a channel fluid passage 521 between the pressure chamber 412 and the manifold 511. Channel fluid passages 520-521 represent different paths for printing fluid, for example, to flow into the pressure chamber 412 from the manifold 510, and different paths for (un-ejected) printing fluid to flow out of the pressure chamber 412 to the manifold 511 (or in the opposite direction).

[0053] Similarly, each injection passage 402 in row 502 includes a pressure chamber 412 in the manifold 514 and the injection passage 402 (see also...). Figure 4 The system includes a fluid passage 520 between the injection channel 402 and the manifold 515, and also includes a fluid passage 521 between the pressure chamber 412 and the manifold 515. Fluid passages 520-521 represent different paths for printing fluid, for example, to flow into the pressure chamber 412 from the manifold 514, and different paths for (un-ejected) printing fluid to flow out of the pressure chamber 412 to the manifold 515 (or in the opposite direction).

[0054] In one embodiment, the main portions or segments of manifolds 510-511 and 514-515 are arranged longitudinally (i.e., along the x-axis) within the printhead 104 to be fluidly connected to the jet channels 402 disposed in rows 501-502. In some flow-through printheads, the return manifold and the supply manifold are arranged longitudinally on the same side of a row of jet channels. In the embodiment described here, manifolds 510-511 are disposed on opposite sides of row 501 of jet channels 402. Similarly, manifolds 514-515 are disposed on opposite sides of row 502 of jet channels 402. To illustrate this configuration, longitudinal sides 312-313 of the printhead 104 are shown. Manifold 510 is disposed on one side 570 (i.e., the first side) of row 501 of the injection passage 402 between longitudinal side 312 and row 501, and manifold 511 is disposed on the other side 572 (i.e., the second side) of row 501 of the injection passage 402 between adjacent rows 501-502 (i.e., between row 501 and longitudinal centerline 310). A "side" of a row of injection passages 402 includes the longitudinal side along the length of the row. Manifold 511 is disposed in the intermediate region 550 between rows 501-502 of the injection passage 402, as a channel fluid passage 521 of each injection passage 402 in the same row 501. Similarly, manifold 514 is disposed on one side 574 (i.e., the first side) of the injection passage 402 between the longitudinal side 313 and the row 502, and manifold 515 is disposed on the other side 576 (i.e., the second side) of the injection passage 402 between adjacent rows 501-502 (i.e., between row 502 and the longitudinal centerline 310). Manifold 515 is disposed in the intermediate region 550 between rows 501-502, as in the channel fluid passage 521 of each injection passage 402 in the same row 502. Therefore, manifold 511 is disposed between row 501 and manifold 515, and manifold 515 is disposed between row 502 and manifold 511.

[0055] exist Figure 5B For example, manifold 510 may be fluidly connected to I / O port 211 to receive printing fluid from an external source, and manifold 511 may be fluidly connected to I / O port 212 to provide an outlet path for the printing fluid from printhead 104 to an external container. Similarly, for example, manifold 514 may be fluidly connected to I / O port 213 to receive printing fluid from an external source, and manifold 515 may be fluidly connected to I / O port 214 to provide an outlet path for the printing fluid from printhead 104 to an external container. For simplicity, it should be understood that the above refers to... Figure 5A The concepts described are applicable Figure 5B The configuration in [the system / system].

[0056] exist Figure 5CIn this configuration, printhead 104 may include additional I / O ports 591-594. For example, manifold 510 may be fluidly connected to I / O ports 211-212, manifold 511 may be fluidly connected to I / O ports 591-592, manifold 514 may be fluidly connected to I / O ports 213-214, and manifold 515 may be fluidly connected to I / O ports 593-594. For the sake of brevity, it should be understood that the above refers to... Figure 5A The concepts described are applicable Figure 5C The configuration in [the system / system].

[0057] exist Figures 5A-5C In the configuration shown, printhead 104 can be operated to eject a single type of printing fluid (e.g., a single color) or two different types of printing fluid (e.g., two colors). However, printhead 104 can be configured to eject more types of printing fluid. Figure 5D This is a schematic diagram of a printhead 104 in an exemplary embodiment. In this embodiment, the printhead 104 includes manifolds 510-511, 514-515, 530-531, and 534-535. In row 501, a sub-manifold of the jet channel 402 is fluidly connected to manifolds 510-511, and a sub-manifold of the jet channel 402 is fluidly connected to manifolds 530-531. In row 502, a sub-manifold of the jet channel 402 is fluidly connected to manifolds 514-515, and a sub-manifold of the jet channel 402 is fluidly connected to manifolds 534-535. For simplicity, it should be understood that the above refers to... Figure 5A The concepts described are applicable Figure 5D The configuration in [the system / configuration]. Figure 5D In the configuration shown, the printhead 104 can be operated to eject a single type of printing fluid (e.g., a single color), two different types of printing fluid (e.g., two colors), or four different types of printing fluid (e.g., four colors).

[0058] One or more methods can be used to circulate the printing fluid through the jet channels 402 of the printhead 104. For example, the pressure in manifolds 510 and / or 511 can be adjusted to create a pressure differential between manifolds 510 and 511. This pressure differential causes the printing fluid to flow through the jet channels 402 in row 501. Similarly, the pressure in manifolds 514 and / or 515 can be adjusted to create a pressure differential between manifolds 514 and 515. This pressure differential causes the printing fluid to flow through the jet channels 402 in row 502.

[0059] Figures 6A-6B This is a cross-sectional view of a portion of the printhead 104 in an exemplary embodiment. Figures 6A-6B The printhead 104 is shown along Figure 3 The cross-section of the cutting plane 6-6 in the diagram. Figure 6AIn the image, two injection channels 402 are shown in adjacent rows 501-502. (As shown...) Figure 4 As shown, the jet channel 402 includes a diaphragm 410, a pressure chamber 412, and a nozzle 306 (note that the nozzle 306 of the jet channel 402 in row 502 is not visible in this cross-section). A manifold 510 of the printhead 104 is fluidly coupled to the jet channel 402 of row 501. More specifically, the pressure chamber 412 of the jet channel 402 is fluidly coupled to the manifold 510 via a channel fluid passage 520. In one embodiment, the channel fluid passage 520 may include / contain a flow restrictor that controls or regulates the flow of print fluid between the manifold 510 and the pressure chamber 412 along the channel fluid passage 520. The pressure chamber 412 of the jet channel 402 is also fluidly coupled to the manifold 511 via a channel fluid passage 521.

[0060] The manifold 514 of printhead 104 is fluidly connected to the jet passage 402 of row 502. More specifically, the pressure chamber 412 of jet passage 402 is fluidly connected to manifold 514 via channel fluid passage 520. In one embodiment, channel fluid passage 520 may include / contain a flow restrictor that controls the flow of printing fluid between manifold 514 and pressure chamber 412 along channel fluid passage 520. The pressure chamber 412 of jet passage 402 is also fluidly connected to manifold 515 via channel fluid passage 521.

[0061] like Figure 6A As shown, rows 501 and 502 of the jet channels 402 are adjacent to each other within the printhead 104 and separated by a longitudinal centerline 310. Manifolds 511 and 515 are disposed in the intermediate region 550 of the printhead 104 / plate stack 232 located between rows 501-502 of the jet channels 402. More specifically, manifolds 511 and 515 are disposed between pressure chambers 412 of the jet channels 402 in adjacent rows 501-502. For the jet channels 402 in row 501, manifold 510 is disposed on one side (along the y-axis) of the pressure chamber 412 in the outer region 652 of the printhead 104 / plate stack 232 between row 501 of the jet channels 402 and the longitudinal side 312. Manifold 510 is fluidly connected to the pressure chamber 412 via a channel fluid passage 520 also disposed in the outer region 652. Manifold 511 is positioned on the other side of pressure chamber 412 (relative to manifold 510) along the y-axis in intermediate region 550. Manifold 511 is positioned between pressure chamber 412 and longitudinal centerline 310 and can be fluidly isolated from injection passage 402 in manifold 515 and / or row 502.

[0062] For the jet passage 402 in row 502, a manifold 514 is disposed on one side (along the y-axis) of the pressure chamber 412 in the outer region 654 of the printhead 104 / plate stack 232 between row 502 and longitudinal side 313 of the jet passage 402. The manifold 514 is fluidly connected to the pressure chamber 412 via a channel fluid passage 520 also disposed in the outer region 654. A manifold 515 is disposed on the other side of the pressure chamber 412 (relative to the manifold 514) along the y-axis in the intermediate region 550. The manifold 515 is disposed between the pressure chamber 412 and the longitudinal centerline 310 and can be fluidly isolated from the manifold 511 and / or the jet passage 402 in row 501.

[0063] Figure 6B A cross-section of the injection channel 402 in row 501 is shown. Figure 6B The arrows in the diagram illustrate the flow of printing fluid from manifold 510 to jet channel 402 and from jet channel 402 to manifold 511. Printing fluid 680 flows from manifold 510 into pressure chamber 412 through channel fluid passage 520. One wall of pressure chamber 412 is formed with a diaphragm 410 physically engaged with actuator 416. Diaphragm 410 may comprise a semi-flexible sheet of material that vibrates in response to actuation of actuator 416. To eject from jet channel 402, one or more jet pulses are sent to actuator 416, which actuates or “activates” in response to the jet pulses. Activation of actuator 416 generates a pressure wave in pressure chamber 412, which causes one or more droplets to be ejected from nozzle 306. Unejected printing fluid 682 that is not ejected from nozzle 306 flows from pressure chamber 412 into manifold 511 through channel fluid passage 521.

[0064] Figure 7This is a perspective view of the jet channel 402 in an exemplary embodiment. As described above, the jet channel 402 includes a pressure chamber 412, a diaphragm 410, and a nozzle 306. The pressure chamber 412 has a length 702 (i.e., along the y-axis), a width 703 (i.e., along the x-axis), and a height 704 (i.e., along the z-axis). The jet channel 402 also includes channel fluid passages 520-521. Typically, the main flow of printing fluid flows longitudinally or along the length direction of the y-axis through the jet channel 402. In embodiments where the flow is in the flow direction 714, the printing fluid flows into one side 710 (i.e., the first side) of the pressure chamber 412 through the channel fluid passages 520. The printing fluid (i.e., unjet printing fluid) flows out of the opposite side 711 (i.e., the second side) of the pressure chamber 412 through the channel fluid passages 520 and 521. Thus, the printing fluid flows into and out of the pressure chamber 412 along the same length direction (i.e., along the y-axis) of the jet channel 402 via the channel fluid passages 520 and 521. Furthermore, the first side 710 of the pressure chamber 412 is positioned closer to the longitudinal sides 312-313 of the printhead 104 than the second side 711, while the second side 711 is positioned closer to the central region 550 of the printhead 104 than the first side 710 (see...). Figure 6A In this configuration, fluid passages 520 and 521 are arranged along the length of the pressure chamber 412 on opposite sides 710-711. For example, fluid passages 520 and 521 are arranged relative to nozzle 306 on opposite sides 710-711 of the pressure chamber 412. Note again that in other embodiments, the flow direction 714 may be reversed.

[0065] like Figure 4 The injection channel 402 shown in Figures 6A-6B and 7 is an example illustrating the basic structure of an injection channel, such as a diaphragm, pressure chamber, nozzle, and channel fluid passage. Other types of injection channels are also considered herein. For example, some injection channels may have... Figure 4 Pressure chambers with different shapes are shown in 6A-6B and 7; some injection channels can have the same shape as... Figures 6A-6B Channel fluid passages 521 and others with different shapes as shown in Figure 7.

[0066] Figure 8An exploded perspective view of the head member 202 of the printhead 104 in an exemplary embodiment is shown. In this embodiment, the head member 202 is an assembly including a housing 230 and a plate stack 232. The plate stack 232 is secured or attached to an engagement surface 880 of the housing 230 and forms multiple rows of jet channels 402. The housing 230 is an elongated member made of a rigid material, such as stainless steel. The housing 230 has a length, width, and height, and the dimensions of the housing 230 are such that the length is greater than the width. The orientation of a row of jet channels 402 corresponds to the length of the housing 230. The housing 230 includes an inlet hole 234 at or near its center, which extends from an I / O surface (not visible) to the opposing engagement surface 880. The inlet hole 234 provides passage for actuator assemblies (not shown), such as multiple piezoelectric actuators, to pass through and contact the diaphragm 410 of the jet channels 402. The engagement surface 880 is the surface of the housing 230 facing the plate stack 232 and engaging with the plates of the plate stack 232. The housing 230 also includes manifold conduits 882-883 extending longitudinally along the length of the mating surface 880. The manifold conduits 882-883 include elongated cuts or grooves along the mating surface 880, configured to deliver printing fluid and form at least a portion of the manifold for the printhead 104.

[0067] The board stack 232 includes a series of boards 801-805 and 304, which are fixed or joined together to form a laminate structure. Figure 8 The plate stack 232 shown is an example of a basic printhead structure. It can have... Figure 8 Additional plates, not shown in the diagram, are stacked on top of each other in plate 232, and the construction of each plate can be varied as needed. Furthermore, Figure 8 It was not drawn to scale.

[0068] In one embodiment, the plate stack 232 includes the following plates: a diaphragm plate 801, a support plate 802, a flow restrictor plate 803, cavity plates 804-805, and a nozzle plate 304. The diaphragm plate 801 is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is generally rectangular in shape and substantially flat or planar. The diaphragm plate 801 includes a diaphragm 811, which comprises a semi-flexible sheet of material forming a diaphragm 410 for a row of injection channels 402. The diaphragm plate 801 also includes manifold openings 812-813. A manifold opening is a aperture or hole forming at least a portion of a manifold for a row of injection channels 402. The manifold opening 812 extends longitudinally along the diaphragm plate 801 between a longitudinal side 890 of the diaphragm plate 801 and the diaphragm 811 for a row of injection channels 402, and is fluidly connected to a manifold conduit 882 of the housing 230. The manifold opening 813 extends longitudinally along the diaphragm plate 801 between another longitudinal side 891 of the diaphragm plate 801 and the diaphragm 811 for another row of injection channels 402, and is fluidly connected to the manifold conduit 883 of the housing 230.

[0069] The support plate 802 (also called a spacer) is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is generally rectangular in shape and substantially flat or planar. The support plate 802 includes manifold openings 822-823, cavity openings 824-825, and manifold openings 826-827. The cavity openings 824 include orifices or holes generally arranged longitudinally in linear rows 828 and configured to form at least a portion of the pressure chamber 412 in the injection passage 402 of the first row 501. The manifold openings 822 are elongated openings that extend longitudinally along the support plate 802 between the longitudinal side 892 of the support plate 802 and the cavity openings 824 in the linear rows 828, and are generally parallel to the linear rows 828 of the cavity openings 824. Manifold opening 826 is an elongated opening that extends longitudinally along the support plate 802 between the linear row 828 of cavity opening 824 and the longitudinal centerline 821 of support plate 802, and is generally parallel to the linear row 828 of cavity opening 824. Cavity opening 825 includes orifices or holes generally arranged longitudinally in linear rows 829 and is configured to form at least a portion of a pressure chamber 412 for the injection passage 402 of the second (adjacent) row 502. Manifold opening 823 is an elongated opening that extends longitudinally along the support plate 802 between the cavity opening 825 in the linear row 829 and on another longitudinal side 893 of support plate 802, and is generally parallel to the linear row 829 of cavity opening 825. Manifold opening 827 is an elongated opening that extends longitudinally along the support plate 802 between the linear row 829 of cavity opening 825 and the longitudinal centerline 821 of support plate 802, and is generally parallel to the linear row 829 of cavity opening 825.

[0070] The flow restrictor plate 803 is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is generally rectangular and substantially flat or planar. The flow restrictor plate 803 includes flow restrictor openings 834-835 and channel connector openings 836-837. The flow restrictor openings 834 are elongated apertures or holes, each laterally oriented and generally arranged longitudinally in a linear row 832. The flow restrictor openings 834 are configured to fluidly connect the pressure chambers 412 of the injection channels 402 of the first row 501 to a manifold (i.e., formed by manifold openings 822, manifold openings 812, etc.). The flow restrictor openings 834 at least partially define a flow restrictor (or channel fluid passage 520) for each injection channel 402 in the first row 501. Thus, each flow restrictor opening 834 is configured to fluidly connect a single pressure chamber 412 of the injection channel 402 in the first row 501 to a manifold (e.g., manifold 510). The channel connector opening 836 includes orifices or holes generally arranged in linear rows 870, parallel to linear rows 832 of the restrictor opening 834. The channel connector opening 836 is disposed between the restrictor opening 834 and the longitudinal centerline 831 of the restrictor plate 803. The channel connector opening 836 is configured to fluidly connect the pressure chamber 412 of the injection passage 402 in the first row 501 to a manifold (i.e., formed by manifold opening 826). The restrictor opening 835 is an elongated orifice or hole, each orifice or hole laterally oriented and generally arranged longitudinally in linear rows 833. The restrictor opening 835 is configured to fluidly connect the pressure chamber 412 of the injection passage 402 in the second row 502 to a manifold (i.e., formed by manifold opening 823, manifold opening 813, etc.). The restrictor opening 835 at least partially defines a restrictor for the individual injection passage 402 in the second row 502. Therefore, each of the flow restrictor openings 835 is configured to fluidly connect a single pressure chamber 412 of the injection passage 402 in the second row 502 to a manifold (e.g., manifold 514). The channel connector opening 837 includes orifices or holes generally arranged in a linear row 871 parallel to the linear row 833 of the flow restrictor openings 835. The channel connector opening 837 is disposed between the flow restrictor openings 835 and the longitudinal centerline 831 of the flow restrictor plate 803. The channel connector opening 837 is configured to fluidly connect the pressure chamber 412 of the injection passage 402 in the second row 502 to a manifold (i.e., formed by the manifold opening 827). The flow restrictor plate 803 also includes inter-manifold openings 838-839. The inter-manifold opening 838 is an elongated orifice or hole, each orifice or hole laterally oriented, and at least partially forms an inter-manifold fluid passage 512 configured to fluidly connect two manifolds. The manifold opening 839 is an elongated pore or hole, each pore or hole being laterally oriented and at least partially forming an inter-manifold fluid passage 516 configured to fluidly connect the two manifolds.

[0071] The cavity plate 804 is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is generally rectangular in shape and substantially flat or planar. The cavity plate 804 includes cavity openings 844-845 and channel connector openings 846-847. The cavity openings 844 are orifices or holes generally arranged longitudinally in linear rows 842 and forming at least a portion of the pressure chambers 412 of the injection channels 402 in the first row 501. The channel connector openings 846 include orifices or holes generally arranged in linear rows 872, parallel to the linear rows 842 of the cavity openings 844. The channel connector openings 846 are disposed between the cavity openings 844 and the longitudinal centerline 841 of the cavity plate 804. Each of the channel connector openings 846 is configured to fluidly connect the respective pressure chambers 412 of the injection channels 402 in the first row 501 to a manifold (i.e., formed by manifold opening 826), and thus at least partially form a channel fluid passage 521. The cavity opening 845 is a series of orifices or holes arranged longitudinally in a linear row 843, forming at least a portion of the pressure chamber 412 of the injection passage 402 in the second row 502. The channel connector opening 847 includes orifices or holes arranged in a linear row 873 parallel to the linear row 843 of the cavity opening 845. The channel connector opening 847 is disposed between the cavity opening 845 and the longitudinal centerline 841 of the cavity plate 804. Each of the channel connector openings 847 is configured to fluidly connect a single pressure chamber 412 of the injection passage 402 in the second row 502 to a manifold (i.e., formed by a manifold opening 827), and thus at least partially forms a channel fluid passage 521. The cavity plate 804 also includes inter-manifold openings 848-849. The inter-manifold opening 848 is an elongated orifice or hole, each orifice or hole oriented laterally, and at least partially forms an inter-manifold fluid passage 512 configured to fluidly connect two manifolds. The manifold opening 849 is an elongated pore or hole, each pore or hole being laterally oriented and at least partially forming a manifold fluid passage 516 configured to fluidly connect the two manifolds.

[0072] Cavity plate 805 is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is generally rectangular in shape and substantially flat or planar. Cavity plate 805 includes cavity openings 854-855 and channel connector features 856-857. Cavity opening 854 is a aperture or hole that is generally arranged longitudinally in a linear row 852 and forms at least a portion of the pressure chamber 412 of the injection channel 402 in the first row 501. Channel connector features 856 may include apertures, holes, etchings, etc., which are generally arranged in a linear row 874 parallel to the linear row 852 of cavity openings 854. Channel connector features 856 are disposed between cavity openings 854 and the longitudinal centerline 851 of cavity plate 805. Each channel connector feature 856 is configured to fluidly connect a single pressure chamber 412 of the injection channel 402 in the first row 501 to a manifold (i.e., formed by manifold opening 826) and thus at least partially form a channel fluid passage 521. Cavity opening 855 is a aperture or hole typically arranged longitudinally in a linear row 853 and forms at least a portion of the pressure chamber 412 of the injection channel 402 in the second row 502. Channel connector features 857 include apertures, holes, etchings, etc., typically arranged in a linear row 875 parallel to the linear row 853 of the cavity opening 855. Channel connector features 857 are disposed between the cavity opening 855 and the longitudinal centerline 851 of the cavity plate 805. Each channel connector feature 857 is configured to fluidly connect a single pressure chamber 412 of the injection channel 402 in the second row 502 to a manifold (i.e., formed by manifold opening 827), and thus at least partially form a channel fluid passage 521. Channel connector features 856-857 are generally referred to as "features" because they may include apertures, localized etchings, etc.

[0073] Nozzle plate 304 is a sheet material (e.g., metal (i.e., stainless steel), plastic, etc.) that is typically rectangular in shape and substantially flat or planar. Nozzle plate 304 includes orifices or nozzle holes 860 that form nozzles 306 in the spray channel 402. For example, nozzle holes 860 may be arranged generally longitudinally in linear rows 862 to form nozzles 306 in the spray channel 402 in a first row 501, and may be arranged longitudinally in linear rows 863 to form nozzles 306 in the spray channel 402 in a second row 502. One technical advantage of plate stack 232 is that a flow-through spray channel can be formed with a reduced number of plates.

[0074] In one embodiment, one or both of the cavity plates 804-805 may be etched or otherwise patterned to form a channel fluid passage 521. Figure 9A cavity plate 804 in an exemplary embodiment is shown. As described above, the cavity plate 804 is a substantially flat or planar sheet of material, and therefore has relatively flat surfaces 910-911. Flat surface 910 faces the discharge surface 220 of the printhead 104, while flat surface 911 faces the housing 230. Zoom window 900 shows an enlarged view of the cavity opening 844 and the channel connector opening 846 of the cavity plate 804. The cavity opening 844 is an elongated opening etched or cut into the cavity plate 804, while the channel connector opening 846 is an opening etched or cut into the cavity plate 804 between the cavity opening 844 and the longitudinal centerline 841 of the cavity plate 804. In one embodiment, the cavity plate 804 also includes a partially etched segment 902 that extends partially from the cavity opening 844 to the channel connector opening 846. To form the partially etched segment 902, the cavity plate 804 is partially etched from the flat surface 910 to an etch depth less than the thickness of the cavity plate 804. For example, the partially etched segment 902 may include a “half-etch” where the etch depth is approximately half the thickness of the cavity plate 804. Therefore, the partially etched segment 902 does not form a hole through the cavity plate 804. The partially etched segment 902 begins at the cavity opening 844 and extends along a length 920 (i.e., along the y-axis) toward the channel connector opening 846. In one embodiment, the length 920 of the partially etched segment 902 is less than the distance 930 between the cavity opening 844 and the channel connector opening 846. The width 922 (i.e., along the x-axis) of the partially etched segment 902 may correspond to the width 932 of the cavity opening 844. The partially etched segments 902 can be etched in a similar manner between each cavity opening 844-845 and channel connector opening 846-847 of the cavity plate 804. One technical advantage is that the channel fluid passage 521 can be patterned using existing photolithography processes.

[0075] Figure 10A cavity plate 805 in an exemplary embodiment is shown. As described above, the cavity plate 805 is a substantially flat or flat sheet of material, and therefore has relatively flat surfaces 1010-1011. Flat surface 1010 faces the discharge surface 220 of the printhead 104, while flat surface 1011 faces the housing 230. Zoom window 1000 shows an enlarged view of the cavity opening 854 and the channel connector feature 856 of the cavity plate 805. The cavity opening 854 is an opening etched or cut into the cavity plate 805. In one embodiment, the channel connector feature 856 includes a partially etched segment 1002 in the cavity plate 805. To form the partially etched segment 1002, the cavity plate 805 is partially etched from the flat surface 1011 to an etch depth less than the thickness of the cavity plate 805. For example, the partially etched segment 1002 may include a “half-etch” where the etch depth is approximately half the thickness of the cavity plate 805. Therefore, the partially etched segment 1002 does not form a hole through the cavity plate 805. A partial etched segment 1002 extends along a length 1020 (i.e., along the y-axis) between the longitudinal centerline 851 of the cavity plate 805 and the cavity opening 854. Each channel connector feature 856 of the cavity plate 805 may include the partial etched segment 1002 as described above. In other embodiments, the channel connector feature 856 may include holes, apertures, and partial etched segments, etc. One technical advantage is that the channel fluid passage 521 can be patterned using existing photolithography processes.

[0076] Figure 8-10 The configuration of board stack 232 in the example is provided, and other configurations are considered here.

[0077] Figure 11 It has such Figure 8-10 A cross-sectional view of a portion of the printhead 104 in an illustrative embodiment of the plate stack 232 shown. Figure 11 The printhead 104 is shown along Figure 3 The cross-section of section 6-6 in the figure is shown to illustrate the jet channel 402 in row 501. The printhead 104 includes a housing 230 and a plate stack 232 fixed or connected to the housing 230 to form the jet channel 402. As described above, the plate stack 232 includes a diaphragm plate 801, a support plate 802, a flow restrictor plate 803, cavity plates 804-805, and a nozzle plate 304. The nozzle orifice 860 of the nozzle plate 304 defines the nozzle 306 of the jet channel 402 (see also...). Figure 8The cavity opening 854 of cavity plate 805, the cavity opening 844 of cavity plate 804, the flow restrictor opening 834 of flow restrictor plate 803, and the cavity opening 824 of support plate 802 form or define the pressure chamber 412 of injection passage 402. The flow restrictor opening 834, combined with cavity plate 804 and support plate 802, forms or defines a flow restrictor 1110, which includes a channel fluid passage 520 configured to control or regulate the flow of printing fluid between manifold 510 and pressure chamber 412. The manifold openings 812 and 822 of diaphragm plate 801 and support plate 802, combined with manifold conduit 882 of housing 230, form or define manifold 510. Although in Figure 11 (Not shown in the diagram) The manifold openings 813 and 823 of the diaphragm plate 801 and the support plate 802 combine with the manifold conduit 883 of the housing 230 to form or define the manifold 514, as shown in the diagram. Figure 6A and 8 As shown. The manifold opening 826 of the support plate 802 defines the manifold 511. The channel connector opening 836 of the flow restrictor plate 803, the channel connector opening 846 of the cavity plate 804, and the channel connector feature 856 of the cavity plate 805 form or define a channel fluid passage 521 between the pressure chamber 412 and the manifold 511. Although in Figure 11 Not shown in the diagram, but the manifold opening 827 of the support plate 802 defines, as Figure 6A and 8 The manifold 515 is shown. The channel connector opening 837 of the flow restrictor plate 803, the channel connector opening 847 of the cavity plate 804, and the channel connector feature 857 of the cavity plate 805 form or define a channel fluid passage 521 between the pressure chamber 412 and the manifold 515, as shown. Figure 6A and 8 As shown. In one embodiment, manifolds 511 and 515 are formed by a support plate 802. In one embodiment, manifolds 510 and 514 are formed by at least a support plate 802.

[0078] One technical advantage of the aforementioned printhead 104 structure is that by directing unsprayed printing fluid to the center of the printhead 104, the printing fluid can circulate through the jet channel 402, preventing the printing fluid from drying or settling within the jet channel 402. Another advantage is that the channel fluid passage 521, positioned towards the center of the printhead 104, is a shorter conduit than in other designs, resulting in lower fluid resistance and faster discharge of unsprayed printing fluid from the jet channel 402 (i.e., faster circulation time). This design also allows for fewer boards stacked 232, reducing manufacturing costs and allowing for higher frequency jetting.

[0079] Figure 12 This is a flowchart illustrating a method 1200 for operating printhead 104 in an illustrative embodiment. The steps of method 1200 will be referred to... Figure 5A The method 1200 is described using printhead 104, but those skilled in the art will understand that it can be performed by other printheads. Furthermore, the steps in the flowchart described herein are not exhaustive and may include other steps not shown, and these steps may be performed in an alternative order.

[0080] For method 1200, assume that printhead 104 includes jet channels 402 in a row 501 fluidly connected to manifolds 510-511, which are located on opposite sides of the row 501. For each jet channel 402 in the row 501 (or a subset of jet channels 402 in the row 501), printing fluid is delivered from manifold 510 (i.e., the first manifold) to pressure chamber 412, for example, through a separate channel fluid passage 520 for that jet channel 402 (step 1202). Unjetted printing fluid is delivered from pressure chamber 412 to manifold 511 (i.e., the second manifold), for example, through a separate channel fluid passage 521 for that jet channel 402 (step 1204).

[0081] In step 1204, the unsprayed printing fluid can flow out of the pressure chamber 412 into the manifold 511 in the same direction as the printing fluid flowing from the manifold 510 into the pressure chamber 412 (i.e., along the y-axis). Figure 7 For example, printing fluid flows into pressure chamber 412 in the direction indicated by the arrow (i.e., from left to right), and un-ejected printing fluid flows out of pressure chamber 412 in the same direction. Therefore, printing fluid can flow into and out of pressure chamber 412 along the same length of the ejection channel 402 (i.e., along the y-axis) via channel fluid passages 520 and 521. Similarly, for step 1204, printing fluid can flow into one side 710 (i.e., the first side) of pressure chamber 412 via channel fluid passage 520 and out of the opposite side 711 (i.e., the second side) of pressure chamber 412 via channel fluid passage 521, as shown in the arrow. Figure 7 As shown. One technical benefit of conveying the printing fluid from the opposite side of row 501 into and out of pressure chamber 412 is that un-ejected printing fluid does not need to be redirected in the opposite direction (i.e., along the y-axis), which results in less fluid resistance and faster discharge of un-ejected printing fluid from ejection channel 402 (i.e., faster cycle time).

[0082] In a printhead, such as the printhead 104 disclosed above, nozzle malfunctions can occur due to various factors, such as drying of the printing fluid at the nozzle or meniscus, sedimentation of the printing fluid, and the presence of air bubbles in the printing fluid. These and other nozzle malfunctions can lead to poor print quality. Therefore, it may be beneficial to mix or agitate the printing fluid in a separate jet channel 402. In-channel passive mixer

[0083] In one embodiment, one or more in-channel passive mixers may be implemented in the injection channel 402. Figure 13 This is a perspective view of an injection channel 402 having one or more passive mixers 1302 within a channel, as described in the illustrative embodiment. Figure 13 The diaphragm 410 is removed. Typically, the printing fluid flows along the longitudinal or length direction (i.e., along the y-axis) of the jet channel 402. Each jet channel 402 has a length 1350 along the y-axis, and the printing fluid flows along the length 1350 of the jet channel 402, commonly referred to as longitudinal flow. In embodiments along the flow direction 714, for example, the printing fluid flows through the channel fluid passage 520 (e.g., from the manifold 510) into the pressure chamber 412. The printing fluid also flows along the pressure chamber 412, in which the printing fluid is either ejected from the nozzle 306 or circulated through the channel fluid passage 521. Therefore, the channel fluid passage 520 and the pressure chamber 412 may each include a longitudinal flow path 1310 of the printing fluid along the length 1350 of the jet channel 402.

[0084] Each jet channel 402 includes a vertical sidewall along the z-axis. The vertical sidewall of the jet channel 402 is typically perpendicular to or transverse to the plane 1354 of the discharge surface 220 of the printhead 104. Printing fluid is typically jetted from the nozzle 306 of the jet channel 402 along the z-axis, and the vertical sidewall of the jet channel 402 is parallel to the jetting direction of the jet channel 402. For example, the channel fluid passage 520 of the jet channel 402 includes opposing vertical sidewalls 1322-1323, and the pressure chamber 412 includes opposing vertical sidewalls 1324-1325. In one embodiment, one or more in-channel passive mixers 1302 may be disposed in the jet channel 402. The in-channel passive mixer 1302 includes protrusions, projections, ribs, or other structural elements within the jet channel that protrude or project from the vertical sidewall of the jet channel (e.g., horizontally along the x-axis) into the longitudinal flow path 1310 of the printing fluid along the length 1350 of the jet channel. Therefore, the passive mixer 1302 protrudes over the width 1352 of the injection channel 402.

[0085] In one embodiment, one or more in-channel passive mixers 1302 may be disposed at the channel fluid passage 520 (e.g., at the flow restrictor 1110). Therefore, one or more in-channel passive mixers 1302 may protrude from the vertical sidewalls 1322-1323 of the channel fluid passage 520. A technical advantage of implementing the in-channel passive mixer 1302 in the channel fluid passage 520 is that the printing fluid is mixed before entering the pressure chamber 412. In one embodiment, one or more in-channel passive mixers 1302 may be disposed at the pressure chamber 412. Therefore, one or more in-channel passive mixers 1302 may protrude from the vertical sidewalls 1324-1325 of the pressure chamber 412. A technical advantage of implementing the in-channel passive mixer 1302 in the pressure chamber 412 is that the printing fluid is mixed within the pressure chamber 412. In one embodiment, the in-channel passive mixer 1302 may be disposed at both the channel fluid passage 520 and the pressure chamber 412, as... Figure 13 As shown. Although the injection channel 402 may include multiple vertical sidewalls, the passive mixer 1302 within the channel may protrude from the vertical sidewalls, which are generally parallel to the length 1350 of the injection channel 402 (i.e., along the y-axis) and generally perpendicular to or transverse to the width 1352 of the injection channel 402 (i.e., along the x-axis), as shown. Figure 13 As shown. Other injection channels 402 can have a similar structure to the passive mixer 1302 within the channel, such as... Figure 13 As shown.

[0086] Figures 14A-14H This is a plan view of the passive mixer 1302 within the jet channel 402 in the illustrative embodiment. Figure 14A This is a plan view of a channel fluid passage 520 having multiple in-channel passive mixers 1302. The channel fluid passage 520 has a width 1410 along the x-axis, and each in-channel passive mixer 1302 extends or protrudes inward from the sidewalls 1322-1323 of the channel fluid passage 520 by a distance 1412. The distance 1412 by which the in-channel passive mixer 1302 protrudes inward from the sidewalls 1322-1323 along the x-direction can be in the range of approximately 30-70 micrometers, approximately 10-60% of the width 1410 of the channel fluid passage 520, etc. The length of the in-channel passive mixer 1302 in the y-direction can be approximately 10-50 micrometers. Each in-channel passive mixer 1302 can protrude by approximately the same distance 1412, or the distance 1412 of different in-channel passive mixers 1302 can be different. Figure 14BThis is a plan view of the channel fluid passage 520, showing the longitudinal flow 1418 of the printing fluid (indicated by arrows). In a typical printhead, the flow of printing fluid along the jet channel is laminar (or streamlined). Laminar flow is a fluid flow in which the fluid flows smoothly or along a regular path. When the printing fluid flows along the channel fluid passage 520 (i.e., in...), Figure 14B (From left to right) When the print fluid encounters the in-channel passive mixer 1302, the in-channel passive mixer 1302 generates turbulence 1420 in the print fluid (i.e., localized turbulence near the in-channel passive mixer 1302). The in-channel passive mixer 1302 represents an obstacle in the channel fluid passage 520 that generates turbulence 1420, where the print fluid experiences irregular fluctuations and mixing. One technical benefit is that the print fluid is mixed within the channel fluid passage 520 by the in-channel passive mixer 1302 to restore the uniformity of the print fluid.

[0087] In one embodiment, such as Figure 14A As shown, a pair of passive mixers 1302 within a 1440-channel configuration may be disposed on opposite sidewalls 1322-1323 of the channel fluid passage 520, generally aligned along the width 1410 of the channel fluid passage 520. In one embodiment, the pair of passive mixers 1302 within a 1440-channel configuration may be disposed on opposite sidewalls 1322-1323 and offset or staggered relative to each other along the width 1410 of the channel fluid passage 520, as shown. Figure 14C As shown. Figures 14A-14C The in-channel passive mixer 1302 is shown as typically having a square or rectangular shape 1430. However, in other embodiments, the in-channel passive mixer 1302 may have other shapes. For example, the in-channel passive mixer 1302 may have a shape such as... Figure 14D-14E The approximate triangular shape 1431 is shown. The passive mixer 1302 within the channel may have, as shown... Figure 14F The approximate shape of a shark fin is shown in Figure 1432. Figure 14G As shown, the passive mixer 1302 within the channel may have a generally trapezoidal shape 1433. For example... Figure 14H As shown, the passive mixer 1302 within the channel can have a generally hemispherical shape 1434. Any combination of different shapes can be achieved. Moreover, although in Figures 14A-14H Four in-channel passive mixers 1302 are shown, but the number of in-channel passive mixers 1302 can vary as needed. For example, the number of in-channel passive mixers 1302 and their positions can depend on the turbulence length scale. For low-viscosity printing fluids, fewer in-channel passive mixers 1302 may be required. For higher-viscosity printing fluids, more in-channel passive mixers 1302 may be required. Furthermore, although in Figures 14A-14HThe passive mixer 1302 within the channel fluid passage 520 is shown, but a similar concept applies when the passive mixer 1302 within the channel is positioned within the pressure chamber 412 of the jet channel 402, which is not shown for simplicity. Each shape or combination of shapes used for the passive mixer 1302 provides the technical benefit of generating turbulence in the printing fluid flow to induce mixing of the printing fluid. Moreover, different shapes can be matched to different ink types. For example, inks with heavy-duty pigments, combined with ink viscosity and surface tension, may be more appropriately matched to the shark fin shape 1432 than to the square or rectangular shape 1430, avoiding pigment buildup at dead spots.

[0088] To realize the passive mixer 1302 within the channel fluid passage 520, the flow limiter plate 803 as described above (see Figure 8 The passive mixer 1302 can be etched or patterned with one or more channels. Figure 15 A flow restrictor plate 803 in an exemplary embodiment is shown. Zoom window 1500 shows an enlarged view of a flow restrictor opening 834 on the flow restrictor plate 803. The flow restrictor opening 834 is an elongated opening etched or cut into the flow restrictor plate 803 and has opposing vertical sidewalls 1506-1507. In one embodiment, the flow restrictor opening 834 is etched or patterned with one or more in-channel passive mixers 1302 that protrude inward from the flow restrictor plate 803 into the flow restrictor opening 834. For example, the flow restrictor opening 834 is etched such that the in-channel passive mixers 1302 protrude from the sidewalls 1506-1507 toward the central region of the flow restrictor opening 834. The flow restrictor region 1510 of the flow restrictor opening 834 indicates the location of the flow restrictor 1110 of the jet channel 402. Therefore, the in-channel passive mixer 1302 can be etched or patterned at the flow limiter region 1510, such that the in-channel passive mixer 1302 is positioned at the flow limiter 1110 (e.g., channel fluid passage 520) of the jet channel 402. Each flow limiter opening 834-835 on the flow limiter plate 803 can be patterned in a similar manner. One technical advantage is that the in-channel passive mixer 1302 can be patterned using existing photolithography processes.

[0089] In order to realize the passive mixer 1302 in the channel within the pressure chamber 412, the chamber plate 804 as described above (see Figure 8 The passive mixer 1302 can be etched or patterned within one or more channels. Figure 16A cavity plate 804 in an exemplary embodiment is shown. Zoom window 1600 shows an enlarged view of a cavity opening 844 of the cavity plate 804. The cavity opening 844 is an elongated opening etched or cut into the cavity plate 804 and has opposing sidewalls 1606-1607. In one embodiment, the cavity opening 844 is etched or patterned to protrude inward from the cavity plate 804 into one or more in-channel passive mixers 1302 within the cavity opening 844. For example, the cavity opening 844 is etched such that the in-channel passive mixers 1302 protrude from the sidewalls 1606-1607 toward the central region of the cavity opening 844. Each cavity opening 844-845 on the cavity plate 804 can be patterned in a similar manner. Furthermore, the cavity plate 805 of the board stack 232 can be etched in a similar manner, or as an alternative to etching the cavity plate 804. One technical advantage is that the in-channel passive mixers 1302 can be patterned using existing photolithography processes.

[0090] Figure 17 This is a flowchart illustrating a method 1700 of operating a printhead 104 using one or more passive mixers 1302 within one or more channels in an illustrative embodiment. The steps of method 1700 will be referred to as having... Figure 13 The printhead 104 of the shown jet channel 402 is described, but those skilled in the art will understand that method 1700 can be performed by other printheads. For each jet channel 402, the print fluid flow is delivered along the longitudinal flow path 1310 of the jet channel 402 (step 1702). One or more passive mixers 1302 within the channel disrupt the print fluid flow along the longitudinal flow path 1310 (step 1704). For example, when the print fluid flows through the channel fluid passage 520 into the pressure chamber 412 (see... Figure 13 When the print fluid flows through the pressure chamber 412, one or more passive mixers 1302 within the channel can interfere with the flow of print fluid through the channel fluid passage 520. One technical benefit is that the print fluid is mixed within the jet channel 402 to restore the uniformity of the print fluid. Intracavitary active mixer

[0091] In one embodiment, one or more intracavity active mixers may be implemented in injection channel 402. Figure 18 This is a perspective view of an injection channel 402 having one or more in-cavity active mixers 1802 in an illustrative embodiment. Figure 18The diaphragm 410 has been removed. As described above, each pressure chamber 412 includes a vertical sidewall along the z-axis. In one embodiment, one or more in-chamber active mixers 1802 may be disposed at the pressure chamber 412. The in-chamber active mixer 1802 includes structural elements within the pressure chamber 412 of the injection channel 402, which are configured to oscillate, vibrate, or otherwise move in response to fluid vibrations within the pressure chamber 412. Other injection channels 402 may have similar characteristics to... Figure 18 The intracavity active mixer 1802 shown has a similar structure. One technical benefit of implementing the intracavity active mixer 1802 is that the printing fluid is mixed within the pressure chamber 412 to restore the uniformity of the printing fluid.

[0092] Figure 19 This is a perspective view of an intracavity active mixer 1802 in an illustrative embodiment. The intracavity active mixer 1802 includes a cantilever 1902, which comprises a structural member projecting or protruding from a vertical sidewall of a pressure chamber 412. One end 1904 (i.e., the connecting end) of the cantilever 1902 is rigidly connected to or attached to the vertical sidewall 1822, while the other end 1906 (i.e., the free end) is not attached to the pressure chamber 412 and is freely movable. The cantilever 1902 has a length 1950, a width 1952, and a thickness 1954 or height. Although the dimensions of the cantilever 1902 can vary as needed, the length 1950 of the cantilever 1902 can be in the range of approximately 200-260 micrometers, the width 1952 of the cantilever 1902 can be in the range of approximately 25-35 micrometers, and the thickness 1954 of the cantilever 1902 can be in the range of approximately 15-60 micrometers.

[0093] Figure 20 This is a perspective view of the intracavity active mixer 1802 in another illustrative embodiment. (See also...) Figure 19 As shown, the intracavity active mixer 1802 includes a cantilever 1902, which includes a structural member protruding or projecting from the vertical sidewall of the pressure chamber 412. One end 1904 (i.e., the connecting end) of the cantilever 1902 is rigidly connected to or attached to the vertical sidewall 1822, while the other end 1906 (i.e., the free end) of the cantilever 1902 is not attached to the pressure chamber 412 and is freely movable. In this embodiment, the intracavity active mixer 1802 also includes an end block 2008 at the free end 1906 of the cantilever 1902.

[0094] The free end 1906 of the cantilever 1902 can freely oscillate, vibrate, or otherwise move in response to fluid vibrations within the pressure chamber 412. For example, when the actuator 416 is activated in response to a jet pulse, a pressure wave is generated in the pressure chamber 412, causing droplets to be ejected from their respective nozzles 306. The pressure wave in the printing fluid drives the free end 1906 of the cantilever 1902 to oscillate or vibrate. In other words, the in-cavity active mixer 1802 is driven (e.g., independently) by the energy of the pressure wave, which has the technical advantage of not requiring a separate actuator or drive mechanism to cause the oscillation of the free end 1906 of the cantilever 1902. The oscillation of the cantilever 1902 generates localized eddies and / or turbulence within the pressure chamber 412, which mixes the printing fluid within the pressure chamber 412. Thus, the cantilever 1902 forms a micro-stirrer within the pressure chamber 412. One technical benefit of implementing an intracavity active mixer 1802 with a cantilever 1902 or an end block 2008 is that the print fluid is mixed within the pressure chamber 412 to restore the uniformity of the print fluid. This helps prevent the print fluid from drying or settling within the pressure chamber 412, which can lead to partial or complete blockage of the nozzle 306. Another technical benefit is that the jet channel 402 can self-recover from missing jets caused by air bubbles.

[0095] The pressure wave in pressure chamber 412 will resonate or be absorbed at a characteristic frequency. This characteristic frequency is determined by the geometry of pressure chamber 412 (and other structures of injection channel 402) and its associated fluid properties, and is referred to as the resonant frequency or Helmholtz frequency of injection channel 402. The intracavity active mixer 1802 also has a resonant frequency. For example, the resonant frequency of intracavity active mixer 1802 depends on the elastic modulus (i.e., the stress-to-strain ratio within the elastic deformation range) of the material used to form cantilever 1902 (e.g., stainless steel), the moment of inertia of cantilever 1902 (e.g., a rectangular region), the length 1950 and width 1952 of cantilever 1902, the mass of end block 2008 (if implemented), etc. In one embodiment, the characteristics of intracavity active mixer 1802 can be selected such that the resonant frequency of intracavity active mixer 1802 differs from the Helmholtz frequency of injection channel 402 by a threshold amount. Therefore, the length 1950 and width 1952 of the cantilever 1902, the mass of the end block 2008 (if implemented), the shape of the cantilever 1902, etc., can be selected such that the resonant frequency of the intracavity active mixer 1802 differs from the Helmholtz frequency of the injection channel 402 by a threshold amount. For example, the typical Helmholtz frequency of the injection channel 402 can be in the range of approximately 80-120 kHz, and the resonant frequency of the intracavity active mixer 1802 can be selected or set to be much lower than the Helmholtz frequency, for example, in the range of approximately 0.1-5 kHz. In one embodiment, the resonant frequency of the intracavity active mixer 1802 is selected such that the vibration of the cantilever 1902 is far removed from the Helmholtz frequency of the injection channel 402. One technical advantage is that, due to the wide gap between the Helmholtz frequency of the injection channel 402 and the resonant frequency of the intracavity active mixer 1802, the oscillation of the intracavity active mixer 1802 will not interfere with the injection of the injection channel 402.

[0096] Figure 21A-21I This is a plan view of a pressure chamber 412 having one or more in-cavity active mixers 1802 in an illustrative embodiment. Figure 21A In this configuration, the intracavity active mixer 1802 is connected to the vertical sidewall 1822 of the pressure chamber 412. In one embodiment, the vertical sidewall 1822 is generally perpendicular or transverse to the length 1350 of the injection channel 402 (i.e., along the y-axis) and generally parallel to the width 1352 of the injection channel 402 (i.e., along the x-axis), as shown below. Figure 18 As shown. Figure 21A As shown, the intracavity active mixer 1802 can be located approximately above or aligned with the center of the nozzle 306 in the jet channel 402, which provides the technical benefit of uniformly mixing the printing fluid within the pressure chamber 412. The length of the cantilever 1902 is 1950 (see...). Figure 19The distance 2160 between the vertical sidewall 1822 and the nozzle 306 can be at least as long as the distance between them, such that the intracavity active mixer 1802 overlaps perpendicularly with the nozzle 306 (i.e., along the z-axis), as shown. Figure 21A As shown. In one embodiment, the length of cantilever 1902 is 1950 (see...). Figure 19 The distance 2160 between the vertical sidewall 1822 and the nozzle 306 can be shorter than that between the vertical sidewall 1822 and the nozzle 306, so that the intracavity active mixer 1802 does not overlap perpendicularly with the nozzle 306 (i.e., along the z-axis), as shown below. Figure 21B As shown. In Figure 21C In this process, the in-cavity active mixer 1802 can typically be offset from the nozzle 306 of the injection channel 402, which provides manufacturing flexibility and technical benefits for mixing variations that sometimes need to avoid interference with nozzle function.

[0097] In some embodiments, the intracavity active mixer 1802 may be disposed on different vertical sidewalls of the pressure chamber 412. For example, in Figure 21D In this configuration, the intracavity active mixer 1802 can be connected to another vertical sidewall 2123 of the pressure chamber 412, which is generally perpendicular or transverse to the length 1350 (i.e., along the y-axis) of the injection channel 402 and generally parallel to the width 1352 (i.e., along the x-axis) of the injection channel 402. Figure 21E In this configuration, the intracavity active mixer 1802 can be connected to another vertical sidewall 2124 of the pressure chamber 412, the vertical sidewall 2124 being generally parallel to the length 1350 of the injection channel 402 (i.e., along the y-axis) and generally perpendicular to or transverse to the width 1352 of the injection channel 402 (i.e., along the x-axis). Figure 21F In this configuration, the intracavity active mixer 1802 may be connected to another vertical sidewall 2125 of the pressure chamber 412, which is generally parallel to the length 1350 of the injection channel 402 (i.e., along the y-axis) and generally perpendicular to or transverse to the width 1352 of the injection channel 402 (i.e., along the x-axis). In some embodiments, more than one intracavity active mixer 1802 may be used in the pressure chamber 412. Figure 21G In this configuration, a pair of 2130 intracavity active mixers 1802 can be connected to opposing vertical sidewalls 1822 / 2123. Figure 21H In this configuration, a pair of 2130 intracavity active mixers 1802 can be connected to opposing vertical sidewalls 2124-2125. Figure 21I In the middle, four intracavity active mixers 1802 can be connected to the vertical sidewalls 1822 and 2123-2125. Figure 21A-21IThe technical benefit of each configuration is that the printing fluid is mixed within the pressure chamber 412 to restore the uniformity of the printing fluid. Multiple in-chamber active mixers 1802 can be implemented for different ink types (e.g., higher viscosity inks or heavy-duty inks).

[0098] In order to implement the intracavity active mixer 1802 in the pressure chamber 412, the chamber plate 805 as described above (see Figure 8 One or more intracavity active mixers 1802 can be etched or patterned. Figure 22 A cavity plate 805 in an illustrative embodiment is shown. Zoom window 2200 shows an enlarged view of a cavity opening 854 on the cavity plate 805. The cavity opening 854 is an etched or cut-in opening into the cavity plate 805 and has sidewalls 2206-2209. In one embodiment, the cavity opening 854 is etched or patterned with one or more cantilever 1902 protruding inward from the cavity plate 805 into the cavity active mixer 1802. This etching controls or defines the length 1950 and width 1952 of the cantilever 1902. In one embodiment, the cantilever 1902 may be partially etched on the cavity plate 805 to control or define the thickness 1954 of the cantilever 1902 (shown by hash). Each cavity opening 854-855 on the cavity plate 805 may be patterned in a similar manner. Although in Figure 22 The image shows a cantilever 1902 protruding from the sidewall 2206, but the cavity plate 805 can be etched or patterned in a similar manner to form a shape such as... Figure 21A-21I One or more intracavity active mixers 1802 are shown. One technical advantage is that the intracavity active mixer 1802 can be patterned using existing photolithography processes, and the dimensions of the cantilever 1902 can be precisely controlled using etching and / or partial etching processes.

[0099] Figure 23 This is a flowchart illustrating a method 2300 for operating a printhead 104 with an in-cavity active mixer 1802 in an illustrative embodiment. The steps of method 2300 will be referred to as having... Figure 18The printhead 104 of the shown jet channel 402 is described, but those skilled in the art will understand that method 2300 can be performed by other printheads. For each jet channel 402, printing fluid is received in the pressure chamber 412 of the jet channel 402 (step 2302). The free end 1906 of the cantilever 1902 oscillates to mix the printing fluid in the pressure chamber 412 (step 2304). For example, when the actuator 416 is activated in response to a jet pulse, a pressure wave is generated in the pressure chamber 412, which causes droplets to be ejected from its corresponding nozzle 306. The pressure wave in the printing fluid drives the free end 1906 of the cantilever 1902 to oscillate or vibrate. This acts as a micro-stirrer, which locally agitates the printing fluid within the pressure chamber 412. One technical benefit is that the printing fluid is mixed within the pressure chamber 412 to restore the uniformity of the printing fluid. In-channel fluid mixer

[0100] In one embodiment, one or more in-channel fluid mixers may be implemented in jet channel 402. Figure 24 This is a perspective view of an injection channel 402 having an in-channel fluid mixer 2402 in an illustrative embodiment. Figure 24 The diaphragm 410 is removed. In one embodiment, an in-channel fluid mixer 2402 is disposed at a channel fluid passage 521 that fluidly connects the pressure chamber 412 to the manifold 511. The in-channel fluid mixer 2402 includes structural elements within the jet channel 402 configured to cause cyclic rotation or motion of the printing fluid flowing between the pressure chamber 412 and the manifold 511. The cyclic rotation or motion of the printing fluid generates vortices that mix the printing fluid. Figure 24 As shown, the jet channel 402 (and other jet channels 402 of the printhead 104) may include a flow-through jet channel 540. Therefore, the in-channel fluid mixer 2402 may be configured to cause a circulating rotation or movement of unjetted printing fluid flowing from the pressure chamber 412 through the channel fluid passage 521 to the manifold. However, the in-channel fluid mixer 2402 may be located at different positions within the jet channel 402, or may be used in conjunction with a non-flow-through type jet channel 402. One technical advantage of implementing the in-channel fluid mixer 2402 is that the printing fluid is mixed within the jet channel 402 to restore the uniformity of the printing fluid. Other jet channels 402 may have similar characteristics to... Figure 24 The structure is similar to that of the in-channel fluid mixer 2402 shown.

[0101] Figures 25A-25D An in-channel fluid mixer 2402 is shown in an illustrative embodiment. Figure 25AThis is a perspective view of the fluid mixer 2402 within the channel, which includes an inlet / outlet section 2510 (i.e., a first inlet / outlet section), a cylindrical mixing chamber 2512, and another inlet / outlet section 2514 (i.e., a second inlet / outlet section). In one embodiment, the inlet / outlet section 2510 is located at one side 2516 of the mixing chamber 2512, and the inlet / outlet section 2514 is generally located at the opposite side 2517 of the mixing chamber 2512 (i.e., along the y-axis). Sections 2510 and 2514 are referred to as “inlet / outlet” or “I / O” sections because, depending on the direction of the printing fluid flow through the jet channel 402, the printing fluid can flow into or out of the mixing chamber 2512 through either section 2510 or 2514. If the flow is only in one direction, section 2510 may be referred to as the inlet section, and section 2514 may be referred to as the outlet section. The mixing chamber 2512 is a cavity having a generally cylindrical shape 2519, and the dimensions of the mixing chamber 2512 may be in the range of a diameter 2546 of about 70-90 micrometers and a height 2548 of about 60-120 micrometers. Figure 25B This is a plan view of the fluid mixer 2402 within the channel, showing the flow of printing fluid in one direction. The inlet / outlet section 2510 is configured to receive the printing fluid flow (e.g., un-ejected printing fluid from the pressure chamber 412 of the jet channel 402). Printing fluid flows from the inlet / outlet section 2510 into the mixing chamber 2512. Due to the structure of the mixing chamber 2512, turbulence is generated within it. For example, the volume 2540 of the mixing chamber 2512 may be larger than the volume 2542 of the inlet / outlet section 2510 or the inlet / outlet section 2514 (see [reference]). Figure 25A Furthermore, the cylindrical shape 2519 of the mixing chamber 2512 causes the printing fluid within the mixing chamber 2512 to circulate or move. As the printing fluid rotates around the axis 2520, the circulating or moving of the printing fluid generates eddies 2518. Figure 25C This is a perspective view of the fluid mixer 2402 within the channel, further illustrating the vortex 2518 generated within the mixing chamber 2512 as the printing fluid rotates about axis 2520. Figure 25B-25C In this process, the printing fluid circulating within the mixing chamber 2512 is discharged through the inlet / outlet section 2514 (e.g., toward a manifold). The printing fluid leaving the mixing chamber 2512 is mixed by the turbulence generated within the mixing chamber 2512, which has the technical benefit of restoring the uniformity of the printing fluid. When such... Figure 24 When the in-channel fluid mixer 2402 is implemented in the channel fluid passage 521, the printing fluid can be mixed when / before the printing fluid leaves the jet channel 402 (for flow in one direction), or when the printing fluid enters the jet channel 402 (for flow in the opposite direction).

[0102] In one embodiment, the inlet / outlet segment 2510 may be offset (e.g., horizontally offset) from the mixing chamber 2512 to cause rotation of the printing fluid within the mixing chamber 2512, such as... Figure 25B As shown. For example, the center 2530 of the inlet / outlet segment 2510 (i.e., along the x-axis) may be offset from the center 2532 of the mixing cavity 2512. Meanwhile, the inlet / outlet segment 2514 may be approximately centered relative to the mixing cavity 2512. For example, the center 2534 of the inlet / outlet segment 2514 (i.e., along the x-axis) may be approximately aligned with the center 2532 of the mixing cavity 2512. In one embodiment, the inlet / outlet segment 2514 may be offset (e.g., horizontally offset) from the mixing cavity 2512. Figure 25D This is a plan view of the fluid mixer 2402 within the channel. For example, the center 2534 of the inlet / outlet section 2514 (i.e., along the x-axis) may be offset from the center 2532 of the mixing chamber 2512. In one embodiment, as... Figure 25C As shown, the inlet / outlet section 2510 may be vertically offset from the inlet / outlet section 2514. For example, the center 2530 of the inlet / outlet section 2510 (i.e., along the y-axis) may be offset from the center 2534 of the inlet / outlet section 2514. Each of these configurations has the technical benefit of causing the printing fluid within the mixing chamber 2512 to circulate, rotate, or move.

[0103] The in-channel fluid mixer 2402 described above can be referred to as a passive fluid mixer, and it does not contain any elements or features that actively move to agitate the printing fluid in the mixing chamber 2512. Mixing is achieved by the circulating rotation or movement of the printing fluid within the mixing chamber 2512. Although in Figures 25A-25D An example of an in-channel fluid mixer 2402 is shown, but other structures or designs may also be considered here.

[0104] In one embodiment, such as Figure 8 The cavity plates 804-805 shown can be etched or otherwise patterned to form the in-channel fluid mixer 2402. Figure 26A cavity plate 804 in an exemplary embodiment is shown. As described above, the cavity plate 804 is a substantially flat or planar sheet of material, and therefore has relatively flat surfaces 910-911. Flat surface 910 faces the discharge surface 220 of the printhead 104, while flat surface 911 faces the housing 230. Zoom window 2600 shows an enlarged view of the cavity opening 844 and the channel connector opening 846 of the cavity plate 804. The cavity opening 844 is an elongated opening etched or cut into the cavity plate 804, while the channel connector opening 846 is an opening etched or cut into the cavity plate 804 located between the cavity opening 844 and the longitudinal centerline 841 of the cavity plate 804. In one embodiment, the cavity plate 804 also includes a partially etched segment 2602 that extends partially from the cavity opening 844 to the channel connector opening 846. To form the partially etched segment 2602, the cavity plate 804 is partially etched from the flat surface 910 to an etch depth less than the thickness of the cavity plate 804. For example, the partially etched segment 2602 may include a “half-etch” where the etch depth is approximately half the thickness of the cavity plate 804. Therefore, the partially etched segment 2602 does not form a hole through the cavity plate 804. The partially etched segment 2602 includes a rectangular segment 2604 that begins at the cavity opening 844 and extends along a length 2620 (i.e., along the y-axis) toward the channel connector opening 846. The width 2632 (i.e., along the x-axis) of the rectangular segment 2604 may correspond to the width 932 of the cavity opening 844. The partially etched segment 2602 also includes a disc-shaped or circular segment 2606 that begins at the rectangular segment 2604 and extends along a length 2622 (i.e., along the y-axis) toward the channel connector opening 846. The diameter 2626 (i.e., along the x-axis) of the circular segment 2606 is greater than the width 2632 of the rectangular segment 2604 and may be in the range of approximately 70-90 micrometers. The rectangular segment 2604 of the partially etched segment 2602 forms the inlet / outlet segment 2510 of the in-channel fluid mixer 2402, and the circular segment 2606 forms at least a portion of the mixing chamber 2512 of the in-channel fluid mixer 2402. The partially etched segment 2602 can be etched in a similar manner between each cavity opening 844-845 and each channel connector opening 846-847 of the cavity plate 804. One technical advantage is that the in-channel fluid mixer 2402 can be patterned using existing photolithography processes.

[0105] Figure 27A cavity plate 805 in an illustrative embodiment is shown. As described above, the cavity plate 805 is a substantially flat or flat sheet of material, and therefore has relatively flat surfaces 1010-1011. Flat surface 1010 faces the discharge surface 220 of the printhead 104, while flat surface 1011 faces the housing 230. Zoom window 2700 shows an enlarged view of the cavity opening 854 and the channel connector feature 856 of the cavity plate 805. The cavity opening 854 is an opening etched or cut into the cavity plate 805, and the channel connector feature 856 includes a partially etched segment 2702 etched into the cavity plate 805 between the cavity opening 854 and the longitudinal centerline 851 of the cavity plate 805. To form the partially etched segment 2702, the cavity plate 805 is partially etched from the flat surface 1011 to an etch depth less than the thickness of the cavity plate 805. For example, the partially etched segment 2702 may include a “half-etch” where the etch depth is approximately half the thickness of the cavity plate 805. Therefore, the partially etched segment 2702 does not form a hole through the cavity plate 805. The partially etched segment 2702 includes a rectangular segment 2704 extending along a length 2720 (i.e., along the y-axis) between the longitudinal centerline 851 of the cavity plate 805 and the cavity opening 854. The partially etched segment 2702 also includes a disc-shaped or circular segment 2706 that begins at the rectangular segment 2704 and extends along a length 2722 (i.e., along the y-axis) toward the cavity opening 854. The diameter 2726 (i.e., along the x-axis) of the circular segment 2706 is greater than the width 2732 of the rectangular segment 2704 and can be in the range of approximately 70-90 micrometers. The rectangular segment 2704 of the partially etched segment 2702 forms the inlet-outlet segment 2514 of the in-channel fluid mixer 2402, while the circular segment 2706 forms at least a portion of the mixing cavity 2512 of the in-channel fluid mixer 2402. Partial etched segments 2702 can be etched between each cavity opening 854-855 and each channel connector feature 856-857 of the cavity plate 805 in a similar manner. One technical advantage is that the in-channel fluid mixer 2402 can be patterned using existing photolithography processes.

[0106] Figure 26-27 The construction of the board stack 232 in the document is provided as an example, and other constructions are considered in this document.

[0107] Figure 28 This is a flowchart illustrating a method 2800 for operating a printhead 104 having an in-channel fluid mixer 2402 in an illustrative embodiment. The steps of method 2800 will be referred to as having... Figure 24 The printhead 104 of the jet channel 402 shown is described, but those skilled in the art will understand that method 2800 can be performed by other printheads.

[0108] For method 2800, the in-channel fluid mixer 2402 receives printing fluid (e.g., unsprayed printing fluid) flowing between the pressure chamber 412 and the manifold through the channel fluid passage 521 (step 2802). For example, inlet / outlet section 2510 (see...) Figure 25A The printing fluid can be received from the pressure chamber 412 of the jet channel 402. The fluid mixer 2402 within the channel causes the printing fluid to circulate (step 2804). For example, the printing fluid can flow into the mixing chamber 2512 from the inlet / outlet section 2510, such as... Figure 25B-25C As shown. The mixing chamber 2512 causes the printing fluid to circulate or move, and generates vortices 2518 as the printing fluid rotates about axis 2520 (optional step 2810). The printing fluid is then conveyed from the in-channel fluid mixer 2402 along the channel fluid passage 521 (step 2806). For example, as Figure 25B-25C As shown, the printing fluid circulating within the mixing chamber 2512 is discharged through the inlet / outlet section 2514 (e.g., toward a manifold). One technical benefit is that the printing fluid is mixed within the jet channel 402 to restore the uniformity of the printing fluid.

[0109] The above embodiments of the in-channel passive mixer 1302, the in-cavity active mixer 1802, and the in-channel fluid mixer 2402 refer to, for example, Figure 5A and 6A The flow-through printhead 504 shown in -6B is described. However, one or more of the in-channel passive mixer 1302, the in-cavity active mixer 1802, and the in-channel fluid mixer 2402 can be implemented in different flow-through printheads while maintaining the aforementioned technical benefits. Furthermore, one or more of the in-channel passive mixer 1302, the in-cavity active mixer 1802, and the in-channel fluid mixer 2402 can be implemented in non-flow-through printheads while maintaining the aforementioned technical benefits. Figure 29 This is a cross-section of the flow-through printhead 2904 in an exemplary embodiment. The printhead 2904 has a structure similar to that described above, wherein the jet channels are arranged in one or more rows. However, the flow-through jet channel 2902 has a different structure. For example, the jet channel 2902 includes a first channel fluid passage 2920 and a second channel fluid passage 2921, the first channel fluid passage 2920 fluidly connecting the pressure chamber 412 to the manifold 2910, and the second channel fluid passage 2921 fluidly connecting the pressure chamber 412 to another manifold 2911. In this configuration, printing fluid can flow into and out of the pressure chamber 412 via the channel fluid passages 2920 and 2921 in different length directions (i.e., along the y-axis) of the jet channel 402, rather than in the same direction. Figure 6BAlong the same length direction. For example, printing fluid can flow from manifold 2910 into pressure chamber 412 through channel fluid passage 2920 (i.e., from left to right), and unsprayed printing fluid can flow out of pressure chamber 412 and into manifold 2911 in the opposite direction (i.e., from right to left) through channel fluid passage 2921. Such a flow-through printhead 2904 can implement the in-channel passive mixer 1302, in-cavity active mixer 1802, and / or in-channel fluid mixer 2402 as described above.

[0110] Figure 30 This is a cross-section of a non-flow-through printhead 3004 in an illustrative embodiment. Printhead 3004 has a similar structure to that described above, wherein the jet channels are arranged in one or more rows. However, the jet channels are non-flow-through jet channels 3002. For example, jet channel 3002 includes a single-channel fluid passage 3020 that fluidly connects pressure chamber 412 to manifold 3010. However, there is no return path for un-jetted print fluid to flow out of pressure chamber 412. A non-flow-through printhead 3004 like this can implement the in-channel passive mixer 1302 and / or in-cavity active mixer 1802 as described above, while retaining the aforementioned technical benefits.

[0111] The following terms and / or examples relate to other embodiments or examples. Details of the embodiments may be used anywhere in one or more embodiments. Various features of different embodiments or examples may be combined differently with some included features and others excluded features to suit a variety of different applications. Examples may include, for example, a method, means for performing the actions of the method, the subject matter of at least one machine-readable medium including instructions that, when executed by a machine, cause the machine to perform the actions of the method, or the actions of a device or system according to the embodiments and examples described herein.

[0112] Some embodiments relating to Example 1 include a flow-through printhead comprising a plurality of jet channels arranged generally parallel to each other along the length of the printhead in a first row and a second row, wherein each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet print fluid, a first manifold fluidly connected to the jet channel in the first row; and a second manifold fluidly connected to the jet channel in the first row; wherein the first manifold and the second manifold are disposed on opposite sides of the first row, and the second manifold is disposed in an intermediate region between the first row and the second row.

[0113] Example 2 includes the subject matter of Example 1, wherein each of the injection channels in the first row includes a first channel fluid passage and a second channel fluid passage, the first channel fluid passage fluidly connecting the pressure chamber to the first manifold, and the second channel fluid passage fluidly connecting the pressure chamber to the second manifold. The first channel fluid passage and the second channel fluid passage are located on opposite sides of the pressure chamber.

[0114] Example 3 includes the subject matter of Examples 1 and 2, wherein the printing fluid flows into and out of the pressure chamber via the first channel fluid passage and the second channel fluid passage in the same length direction of the jet channel.

[0115] Example 4 includes the subject of Examples 1-3, where the second channel fluid passage for each jet channel in the first row is set in the middle area.

[0116] Example 5 includes the subject of Examples 1-4, wherein a first manifold is disposed in the outer region between the longitudinal side of the flow-through printhead and the first row, and a first channel fluid passage for each jet channel in the first row is disposed in the outer region.

[0117] Example 6 includes the subject matter of Examples 1-5, and further includes one or more inter-manifold fluid passages that fluidly connect the first manifold and the second manifold.

[0118] Example 7 includes the subject matter of Examples 1-6, and further includes a third manifold fluidly connected to the injection passage in the second row, and a fourth manifold fluidly connected to the injection passage in the second row. The third and fourth manifolds are located on opposite sides of the second row, with the fourth manifold located in the middle region. The second manifold is located between the first and fourth manifolds, and the fourth manifold is located between the second row and the second manifold.

[0119] Example 8 includes the subject matter of Examples 1-7, and also includes a spraying device.

[0120] Some embodiments related to Example 9 include a flow-through printhead comprising a housing and a stack of plates attached to the housing, the stack forming a plurality of jet channels arranged generally parallel to each other along the length of the printhead in a first and second row, wherein each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet printing fluid. The stack of plates forms a first manifold longitudinally disposed and fluidly coupled to the jet channels in the first row, and a second manifold longitudinally disposed and fluidly coupled to the jet channels in the first row. The first and second manifolds are disposed on opposite sides of the first row, with the second manifold disposed in an intermediate region between the first and second rows.

[0121] Example 10 includes the subject matter of Example 9, wherein each of the injection channels in the first row includes a first channel fluid passage and a second channel fluid passage, the first channel fluid passage fluidly connecting the pressure chamber to a first manifold, and the second channel fluid passage fluidly connecting the pressure chamber to a second manifold. The first channel fluid passage and the second channel fluid passage are located on opposite sides of the pressure chamber.

[0122] Example 11 includes the subject matter of Examples 9 and 10, wherein printing fluid flows into and out of the pressure chamber via a first channel fluid passage and a second channel fluid passage in the same length direction of the jet channel.

[0123] Example 12 includes the subject of Examples 9-11, where a second channel fluid passage for each jet channel in the first row is set in the middle region.

[0124] Example 13 includes the subject of Examples 9-12, wherein a first manifold is disposed in the outer region between the longitudinal side of the flow-through printhead and the first row, and a first channel fluid passage for each jet channel in the first row is disposed in the outer region.

[0125] Example 14 includes the subject matter of Examples 9-13, wherein the plate stack comprises: a diaphragm plate forming a diaphragm of an injection channel, a support plate, a flow restrictor plate, a first chamber plate and a second chamber plate forming a pressure chamber of the injection channel, and a nozzle plate having a nozzle orifice defining the injection channel. The support plate forms a first manifold and a second manifold.

[0126] Example 15 includes the subject matter of Examples 9-14, wherein the support plate includes: a cavity opening arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection passage in the first row; a first manifold opening extending longitudinally between a longitudinal side of the support plate and the cavity openings to form at least a portion of the first manifold; and a second manifold opening extending longitudinally between the linear row of the cavity openings and the longitudinal centerline of the support plate to form the second manifold.

[0127] Example 16 includes the subject matter of Examples 9-15, wherein a flow restrictor plate includes: flow restrictor openings arranged generally longitudinally in a linear row, wherein each of the flow restrictor openings is configured to fluidly connect a single pressure chamber of the injection passage in the first row to a first manifold; and channel connector openings arranged generally in a linear row parallel to the linear row of the flow restrictor openings and disposed between the flow restrictor openings and a longitudinal centerline of the flow restrictor plate. Each of the channel connector openings is configured to fluidly connect a single pressure chamber of the injection passage in the first row to a second manifold.

[0128] Example 17 includes the subject matter of Examples 9-16, wherein a first chamber plate includes: a cavity opening arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection passage in the first row; and a channel connector opening arranged generally in a linear row parallel to the linear row of the cavity openings and disposed between the cavity openings and a longitudinal centerline of the first chamber plate. Each of the channel connector openings is configured to fluidly connect a single pressure chamber of the injection passage in the first row to a second manifold.

[0129] Example 18 includes the subject matter of Examples 9-17, wherein the first cavity plate further includes a partially etched segment that extends partially from the cavity opening toward the channel connector opening.

[0130] Example 19 includes the subject matter of Examples 9-18, wherein the second chamber plate includes: a cavity opening arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection passage in the first row; and channel connector features arranged generally in a linear row parallel to the linear row of the cavity openings and disposed between the cavity openings and a longitudinal centerline of the second chamber plate. Each of the channel connector features is configured to fluidly connect a single pressure chamber of the injection passage in the first row to the second manifold.

[0131] Example 20 includes the subject of Examples 9-19, where the channel connector features include partially etched segments.

[0132] Example 21 includes the subject matter of Examples 9-20, and also includes a jetting device.

[0133] Some embodiments relating to Example 22 include a method comprising operating a flow-through printhead comprising a plurality of jet channels arranged generally parallel to the length of the printhead in a first row and a second row, wherein each jet channel includes a diaphragm, a pressure chamber, and a nozzle configured to jet print fluid, a first manifold fluidly coupled to the jet channel in the first row; and a second manifold fluidly coupled to the jet channel in the first row. The first manifold and the second manifold are disposed on opposite sides of the first row, the second manifold being disposed in an intermediate region between the first row and the second row. Operating the printhead includes: for each jet channel in the first row, conveying print fluid from the first manifold on a first side of the first row to the pressure chamber; and for each jet channel in the first row, conveying unjetted print fluid from the pressure chamber to the second manifold, the second manifold being on a second side of the first row opposite to the first side.

[0134] Although specific embodiments have been described herein, the scope of the invention is not limited to these specific embodiments. The scope of the invention is defined by the appended claims and any equivalents thereof.

Claims

1. A flow-through printhead, characterized in that, include: A stack of plates forming multiple jet channels, the multiple jet channels being arranged in a first row and a second row in a generally parallel manner along the length of the printhead, wherein each jet channel includes a diaphragm, a pressure chamber and a nozzle configured to jet printing fluid; A first manifold fluidly connected to the injection channel in the first row; as well as A second manifold fluidly connected to the injection channel in the first row; The first manifold and the second manifold are located on opposite sides of the first row, and the second manifold is located in the middle region between the first row and the second row. The plate stack includes a support plate, wherein the support plate forms the first manifold and the second manifold. The support plate includes: The cavity openings are arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection channel in the first row; A first manifold opening extends longitudinally between the longitudinal side of the support plate and the cavity opening to form at least a portion of the first manifold; and The second manifold opening extends longitudinally between the linear row of the cavity opening and the longitudinal centerline of the support plate to form the second manifold.

2. The flow-through printhead according to claim 1, characterized in that, Each of the injection channels in the first row includes a first channel fluid passage and a second channel fluid passage. The first channel fluid passage fluidly connects the pressure chamber to the first manifold, and the second channel fluid passage fluidly connects the pressure chamber to the second manifold. The first fluid passage and the second fluid passage are located on opposite sides of the pressure chamber.

3. The flow-through printhead according to claim 2, characterized in that, The printing fluid flows into and out of the pressure chamber via the first and second channel fluid passages along the same length of the injection channel.

4. The flow-through printhead according to claim 2, characterized in that, The second channel fluid passage of each of the injection channels in the first row is disposed in the intermediate region.

5. The flow-through printhead according to claim 4, characterized in that, The first manifold is located in the outer region between the longitudinal side of the flow-through printhead and the first row; as well as The first channel fluid passage of each of the injection channels in the first row is disposed in the outer region.

6. The flow-through printhead according to claim 1, characterized in that, Also includes: One or more manifold fluid passages fluidly connect the first manifold and the second manifold.

7. The flow-through printhead according to claim 1, characterized in that, Also includes: A third manifold fluidly connected to the injection channel in the second row; and A fourth manifold fluidly connected to the injection channel in the second row; The third manifold and the fourth manifold are located on opposite sides of the second row, and the fourth manifold is located in the middle area. The second manifold is disposed between the first row and the fourth manifold; The fourth manifold is located between the second row and the second manifold.

8. A spraying device, characterized in that, include: The flow-through printhead as described in claim 1.

9. A flow-through printhead, characterized in that, include: case; and A stack of plates attached to the housing forms a plurality of jet channels, which are arranged in a first and second row in a generally parallel manner along the length of the printhead, wherein each jet channel includes a diaphragm, a pressure chamber and a nozzle configured to jet printing fluid; The plates are stacked to form a first manifold that is longitudinally arranged and fluidly connected to the injection channel in the first row; The plates are stacked to form a second manifold that is longitudinally arranged and fluidly connected to the injection channel in the first row; The first manifold and the second manifold are located on opposite sides of the first row, and the second manifold is located in the middle region between the first row and the second row. The plate stack includes a support plate, wherein the support plate forms the first manifold and the second manifold. The support plate includes: The cavity openings are arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection channel in the first row; A first manifold opening extends longitudinally between the longitudinal side of the support plate and the cavity opening to form at least a portion of the first manifold; and The second manifold opening extends longitudinally between the linear row of the cavity opening and the longitudinal centerline of the support plate to form the second manifold.

10. The flow-through printhead according to claim 9, characterized in that, Each of the injection channels in the first row includes a first channel fluid passage and a second channel fluid passage. The first channel fluid passage fluidly connects the pressure chamber to the first manifold, and the second channel fluid passage fluidly connects the pressure chamber to the second manifold. The first fluid passage and the second fluid passage are located on opposite sides of the pressure chamber.

11. The flow-through printhead according to claim 10, characterized in that, The printing fluid flows into and out of the pressure chamber via the first and second channel fluid passages along the same length of the injection channel.

12. The flow-through printhead according to claim 10, characterized in that, The second channel fluid passage of each of the injection channels in the first row is disposed in the intermediate region.

13. The flow-through printhead according to claim 12, characterized in that, The first manifold is located in the outer region between the longitudinal side of the flow-through printhead and the first row; and The first channel fluid passage of each of the injection channels in the first row is disposed in the outer region.

14. The flow-through printhead according to claim 10, characterized in that, The plate stack further includes: A diaphragm plate that forms the diaphragm of the injection channel; Current limiter board; The first cavity plate and the second cavity plate that form the pressure chamber of the injection channel; and A nozzle plate having a nozzle orifice defining the spray channel.

15. The flow-through printhead according to claim 14, characterized in that, The current limiter plate includes: Flow restrictor openings, the flow restrictor openings being arranged generally longitudinally in a linear row, wherein each of the flow restrictor openings is configured to fluidly connect a single pressure chamber of the injection passage in the first row to the first manifold; and The channel connector openings are arranged in a linear row that is generally parallel to the linear row of the current limiter openings, and are located between the current limiter openings and the longitudinal centerline of the current limiter plate. Each of the channel connector openings is configured to fluidly connect a single pressure chamber of the injection channel in the first row to the second manifold.

16. The flow-through printhead according to claim 14, characterized in that, The first cavity plate includes: Cavity openings, the cavity openings being arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection channel in the first row; and Channel connector openings are arranged in a linear row that is generally parallel to the linear row of the cavity openings and are disposed between the cavity openings and the longitudinal centerline of the first cavity plate. Each of the channel connector openings is configured to fluidly connect a single pressure chamber of the injection channel in the first row to the second manifold.

17. The flow-through printhead according to claim 16, characterized in that, The first cavity plate further includes: A partial etched section extends from the cavity opening toward the channel connector opening.

18. The flow-through printhead according to claim 14, characterized in that, The second cavity plate includes: Cavity openings, the cavity openings being arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection channel in the first row; and The channel connector features are generally arranged in a linear row parallel to the linear row of the cavity opening, and are disposed between the longitudinal centerline of the cavity opening and the second cavity plate. Each of the channel connector features is configured to fluidly connect a single pressure chamber of the injection channel in the first row to the second manifold.

19. The flow-through printhead according to claim 18, characterized in that, The channel connector features include partially etched sections.

20. A spraying device, characterized in that, include: The flow-through printhead as described in claim 9.

21. A method for using a flow-through printhead, characterized in that, include: Operating a flow-through printhead, the flow-through printhead comprising: A stack of plates forming multiple jet channels, the multiple jet channels being arranged in a first row and a second row in a generally parallel manner along the length of the printhead, wherein each of the jet channels includes a diaphragm, a pressure chamber and a nozzle configured to jet printing fluid; A first manifold fluidly connected to the injection channel in the first row; and A second manifold fluidly connected to the injection channel in the first row; The first manifold and the second manifold are disposed on opposite sides of the first row, and the second manifold is disposed in the middle region between the first row and the second row. The plate stack includes a support plate, wherein the support plate forms the first manifold and the second manifold. The support plate includes: The cavity openings are arranged generally longitudinally in a linear row to form at least a portion of the pressure chamber of the injection channel in the first row; A first manifold opening extends longitudinally between the longitudinal side of the support plate and the cavity opening to form at least a portion of the first manifold; and The second manifold opening extends longitudinally between the linear row of the cavity opening and the longitudinal centerline of the support plate to form the second manifold. The operation includes: For each injection channel in the first row, the printing fluid is delivered from the first manifold on the first side of the first row to the pressure chamber; and For each injection channel in the first row, un-ejected printing fluid is delivered from the pressure chamber to the second manifold, which is located on the second side of the first row opposite to the first side.

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