Patent Publication Number: US-11642885-B2

Title: Fluid ejection device including fluid output channel

Description:
BACKGROUND 
     Fluid ejection devices are devices that deposit a fluid, such as ink, on a medium, such as paper. A fluid ejection device may be connected to a fluid reservoir. Accordingly, fluid from the reservoir may be conveyed to the fluid ejection device and expelled, dispensed, and/or ejected therefrom. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram that illustrates some components of an example fluid ejection die. 
         FIGS.  2 A-D  are block diagrams that illustrate some components of example fluid ejection dies. 
         FIG.  3    is a block diagram of some components of an example fluid ejection die. 
         FIG.  4    is a block diagram of some components of an example fluid ejection die. 
         FIG.  5    is a block diagram of some components of an example fluid ejection device. 
         FIG.  6    is a block diagram of some components of an example fluid ejection device. 
         FIG.  7    is a flowchart of an example process. 
     
    
    
     Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings. 
     DETAILED DESCRIPTION 
     Examples of fluid ejection devices and fluid ejection dies thereof may comprise an ejection nozzle, an ejection chamber, a fluid input hole, a fluid output hole, a fluid output channel, and a fluid pump. The fluid input hole may be fluidly connected to the ejection chamber such that fluid may be conveyed to the ejection chamber via the fluid input hole. As will be appreciated, the fluid input hole may be fluidly connected to a fluid reservoir, and fluid from the fluid reservoir may be conveyed to the ejection chamber via the fluid input hole. In some examples, a fluid slot may be fluidly connected to the fluid reservoir and the fluid input hole. The ejection nozzle may be fluidly connected to and adjacent to the ejection chamber such that fluid in the ejection chamber may be ejected from the fluid ejection device via the ejection nozzle. Furthermore, the ejection chamber may be fluidly connected to the fluid output hole via the fluid output channel. The fluid pump is disposed in the fluid output channel. In such examples, fluid in the ejection chamber may be pumped from the ejection chamber out of the fluid output hole via the fluid output channel with the fluid pump. 
     Therefore, in such examples, the fluid ejection device may eject fluid in the ejection chamber via the ejection nozzle or the fluid ejection device may pump fluid from the ejection chamber out of the fluid output hole via the fluid output channel with the fluid pump. In some examples, the fluid output hole and fluid input hole may be fluidly connected to a common fluid slot. Accordingly, in these examples, fluid may be conveyed to the ejection chamber from the fluid slot via the fluid input hole, and the fluid in the ejection chamber may be conveyed to the fluid slot via the fluid output channel and fluid output hole. As will be appreciated, these examples may circulate fluid from the fluid slot, through the ejection chamber, and back into the fluid slot. Moreover, in these examples, the circulation of fluid may be performed in a single flow direction. In other words, the fluid input hole may facilitate conveyance of fluid to the ejection chamber from the fluid slot. The fluid output channel and fluid pump disposed therein may facilitate conveyance of fluid from the ejection chamber to the fluid slot via the fluid output hole. 
     Examples described herein may facilitate improved fluidic response of a fluid ejection device. In some examples, a fluid of the fluid ejection device may have a high concentration of particulate such that, without circulation thereof, the particulate may settle. For example, particulate of a fluid may settle in the ejection chamber. Settling of particulate in the ejection chamber may lead to clogging of the ejection nozzle or undesirable fluidic response. Accordingly, examples described herein may facilitate circulation of fluid through ejection chambers thereof such that particulate settling may be reduced. 
     In some examples, the fluid ejection device may comprise a fluid ejector including a heating element. To eject fluid via the ejection nozzle, the heating element may be electrically activated. Activation of the heating element may cause a vapor bubble to form in fluid proximate the fluid ejector, and the vapor bubble may cause ejection of a fluid drop out of the ejection nozzle. In such examples, it will be appreciated that operation of the fluid ejector may increase thermal profiles of fluid, components, and surfaces proximate the fluid ejector. Therefore, in examples including a fluid ejector including a heating element, circulating fluid through the ejection chamber may facilitate thermal cooling of the ejection chamber. It will be appreciated that even if a heating element is not implemented in a fluid ejector, circulation of fluid through the ejection chamber may reduce a temperature of components and surfaces. 
     In general, ejection nozzles may eject/dispense fluid from a fluidly connected ejection chamber. Nozzles generally include fluid ejectors to cause fluid to be ejected/dispensed from a nozzle orifice. Some examples of types of fluid ejectors implemented in fluid ejection devices include thermal ejectors, piezoelectric ejectors, and/or other such ejectors that may cause fluid to be ejected/dispensed from a nozzle orifice. 
     Moreover, examples described herein may be described as comprising nozzles, ejection chambers, fluid channels, fluid input holes, and/or fluid output holes. It will be appreciated that examples provided herein may be formed by performing various microfabrication and/or micromachining processes on a substrate to form and/or connect structures and/or components. The substrate may comprise a silicon based wafer or other such similar materials used for microfabricated devices (e.g., glass, gallium arsenide, metals, ceramics, plastics, etc.). Examples may comprise fluid channels, fluid actuators, volumetric chambers, nozzle orifices, or any combination thereof. Fluidic channels, nozzles, holes, and/or chambers may be formed by performing etching, microfabrication (e.g., photolithography), micromachining processes, or any combination thereof in a substrate. Accordingly, fluid channels, nozzle orifices, fluid input/output holes, and/or chambers may be defined by surfaces fabricated in the substrate and/or fabricated layers of a microfabricated device. 
     In some examples, fluid ejection dies may be referred to as slivers. Generally, a sliver may correspond to an ejection die having: a thickness of approximately 650 μm or less; exterior dimensions of approximately 30 mm or less; and/or a length to width ratio of approximately 3 to 1 or larger. In some examples, a length to width ratio of a sliver may be approximately 10 to 1 or larger. In some examples, a length to width ratio of a sliver may be approximately 50 to 1 or larger. In some examples, ejection dies may be a non-rectangular shape. In these examples a first portion of the ejection die may have dimensions/features approximating the examples described above, and a second portion of the ejection die may be greater in width and less in length than the first portion. In some examples, a width of the second portion may be approximately 2 times the size of the width of the first portion. In these examples, an ejection die may have an elongate first portion along which ejection nozzles may be arranged, and the ejection die may have a second portion upon which electrical connection points for the ejection die may be arranged. 
     Example fluid ejection devices and fluid ejection dies thereof, as described herein, may be implemented in printing devices, such as two-dimensional printers and/or three-dimensional printers (3D). As will be appreciated, some example fluid ejection devices may be printheads. In some examples, a fluid ejection device may be implemented into a printing device and may be utilized to print content onto a media, such as paper, a layer of powder-based build material, reactive devices (such as lab-on-a-chip devices), etc. Example fluid ejection devices include ink-based ejection devices, digital titration devices, 3D printing devices, pharmaceutical dispensation devices, lab-on-chip devices, fluidic diagnostic circuits, and/or other such devices in which amounts of fluids may be dispensed/ejected. 
     In some examples, a printing device in which a fluid ejection device may be implemented may print content by deposition of consumable fluids in a layer-wise additive manufacturing process. Consumable fluids and/or consumable materials may include all materials and/or compounds used, including, for example, ink, toner, fluids or powders, or other raw material for printing. Furthermore, printing material, as described herein may comprise consumable fluids as well as other consumable materials. Printing material may comprise ink, toner, fluids, powders, colorants, varnishes, finishes, gloss enhancers, binders, and/or other such materials that may be utilized in a printing process. 
     Turning now to the figures, and particularly to  FIG.  1   , this figure provides a block diagram that illustrates some components of an example fluid ejection die  10 . In this example, the fluid ejection die  10  comprises a substrate  12  having a fluid input hole  14  that is fluidly connected to an ejection chamber  16  formed in a nozzle layer  18 . The ejection chamber  16  is positioned adjacent to and fluidly connected with an ejection nozzle  20  that is formed in the nozzle layer  18 . In this example, the fluid ejection die  10  further comprises a fluid output channel fluidly connected to the ejection chamber  16 , and the fluid output channel is further fluidly connected to a fluid output hole  24  that is formed in the substrate  12 . While not shown in this block diagram, in some examples, the fluid ejection die may comprise a fluid pump disposed in the fluid output channel  22  to pump fluid from the ejection chamber  16  to the fluid output hole  24 . Furthermore, some examples may comprise a fluid ejector disposed in the ejection chamber and proximate the ejection nozzle  20  to eject fluid from the ejection chamber  16  via the ejection nozzle  20 . 
     In the example illustrated in  FIG.  1   , it will be noted that the fluid ejection die  10  is illustrated as comprising a substrate  12  and a nozzle layer  18 . It will be appreciated that the substrate  12  and nozzle layer  18  may comprise different materials. For example, the substrate  12  may comprise silicon, and the nozzle layer  18  may comprise a polymer material. Other combinations of materials may be implemented in other examples. Furthermore, in some examples, the nozzle layer  18  and the substrate  12  may be formed of more than two different materials or a single material. 
     As shown in  FIG.  1   , example fluid flow directions  30   a - d  corresponding to the fluid ejection die  10  are provided. In this example, fluid may flow through the fluid input hole  14  to the ejection chamber  16 , as shown with flow direction  30   a . Furthermore, fluid may flow from the ejection chamber  16  through the fluid output channel  22  to the fluid output hole  24 , as shown in flow directions  30   b - c . Alternative to flowing through the fluid output channel  22  and out of the fluid output hole  24 , fluid may be ejected from the ejection chamber  16  through the ejection nozzle  20 , as provided in example fluid flow direction  30   d.    
       FIGS.  2 A-D  provide block diagrams of some example arrangements of components of a fluid ejection device and/or a fluid ejection die thereof. In these examples, a fluid ejection die  50  comprises an ejection chamber  52 . The fluid ejection die  50  further includes a fluid input hole  54  fluidly connected to the ejection chamber  52  with which fluid may be conveyed from a fluid source to the ejection chamber  52 . The fluid ejection die  50  includes an ejection nozzle  56  fluidly connected to the ejection chamber  52 , and the fluid ejection die  50  includes a fluid ejector  58  disposed in the ejection chamber  52 . Furthermore, the ejection chamber  52  is fluidly connected to a fluid output channel  60 , which is also fluidly connected to a fluid output hole  62 . 
     In the examples of  FIGS.  2 A-D  at least one fluid pump  64  is disposed in each fluid output channel  60 . As discussed previously, the fluid ejector  58  may be actuated to cause ejection of a fluid drop from the ejection chamber  52  via the nozzle  56 . The fluid pump  64  may be actuated to cause pumping of fluid from the ejection chamber  52  through the fluid output channel  60  and out of the fluid output hole  62 . In some examples, the fluid pump  64  is positioned closer to the ejection chamber  52  as compared to the fluid outlet hole  62  to facilitate asymmetric pumping of fluid in the fluid output channel  60 . 
     In the example of  FIG.  2 B , the example fluid ejection die  50  includes at least one pillar  66  disposed in the fluid output channel  60  and positioned between the ejection chamber  52  and the fluid pump  64 . In  FIG.  2 C , the example fluid ejection die  50  includes at least two pillars  66 ,  68  disposed in the fluid output channel  60  and positioned between the ejection chamber  52  and the fluid pump  64 . In the examples of  FIGS.  2 B-C , the pillars  668 ,  68  may reduce fluid cross-talk during actuation of the fluid pump  64  and/or fluid ejector  58 . 
     In the example of  FIG.  2 D , the fluid ejection die  50  comprises at least two fluid input holes  54 , at least two ejection chambers  52 , at least two ejection nozzles  56 , at least two fluid ejectors  58 , at least two fluid output channels  60 , and at least two fluid pumps  64 . As will be noted with regard to  FIG.  2 D , the fluid ejection die  50  comprises a single fluid output hole  62  that is fluidly connected to the two fluid ejection chambers  52  and the two fluid output channels  60 . Therefore, in this example, fluid may be pumped from each ejection chamber  52  to the fluid output hole  62 .  FIG.  2 D  further illustrates a fluid circulation rib  70  (illustrated in phantom). As shown, the fluid circulation rib is positioned between the fluid input holes  54  and the fluid output hole  62 . It will be appreciated that, in examples similar to the example of  FIG.  2 D , the fluid recirculation rib  70  may extend along a plane that is approximately orthogonal to a plane along which the fluid output channels  60 , fluid input holes  54 , and fluid output hole  62  may be formed. In such examples, fluid pumped through the fluid output hole  62  may be circulated in a direction approximately parallel to the plane along which the fluid circulation rib  70  extends until passing a point of termination of the fluid circulation rib  70 . Accordingly, it may be appreciated that the fluid circulation rib  70  may inhibit drawing of fluid through a fluid input hole  54  that was output from the fluid output hole  62  until such output fluid has passed the point of termination of the fluid circulation rib  70 . 
     It will be appreciated that the number of respective components illustrated in the examples of  FIGS.  2 A-D  are merely for illustrative purposes. In other examples, the fluid ejection die may comprise more or less of each respective component (e.g., more or less ejection chambers, ejection nozzles, fluid pumps, fluid output channels, etc.). Furthermore, example fluid ejection dies may include other arrangements of such components with regard to number and relative arrangement therebetween. 
       FIG.  3    provides a block diagram that illustrates some components of an example fluid ejection device and/or a fluid ejection die thereof. Similar to the examples of  FIGS.  2 A-D , the example fluid ejection die  100  includes ejection chambers  52 , fluid input holes  54 , ejection nozzles  56 , fluid ejectors  58 , fluid output channels  60 , fluid output channels  60 , fluid output holes  62 , and fluid pumps  64 . Furthermore, in the example of  FIG.  3   , the fluid ejection die includes pillars  102  positioned proximate the fluid input holes  54  and the fluid output holes  62 . As will be appreciated, the pillars  102  may inhibit undesired particulate from entering the ejection chamber  52 . Furthermore, in the example fluid ejection die  100 , the fluid output channels  60  correspond to an S-shape. As used herein, an S-shape may indicate that the fluid output channel  60  includes two curves arranged between sections such that the fluid output channel  60  resembles the shape of the letter ‘S’. In this example, the S-shaped fluid output channels  60  comprise straight sections connected by U-shaped curved sections. It will be appreciated that each respective fluid pump  64  may be positioned in the respective fluid output channel  60  at a position closer in distance to the respective ejection chamber  52  as compared to the distance of the fluid pump  64  to the fluid output hole  62 . The positioning of each respective fluid pump  64  may be described as being asymmetrically arranged in the fluid output channel  60 . 
       FIG.  4    provides a block diagram that illustrates some components of an example fluid ejection device and/or a fluid ejection die thereof. Similar to the examples of  FIGS.  2 A-D  and  3 , the example fluid ejection die  150  includes ejection chambers  52 , fluid input holes  54 , ejection nozzles  56 , fluid ejectors  58 , fluid output channels  60 , fluid output holes  62 , fluid pumps  64 , and pillars  102 . In the example of  FIG.  4   , each respective fluid output channel  60  may be fluidly connected to the respective ejection chamber  52  at a first end and the respective fluid output hole  62  at a second end. As shown, a channel width of each fluid output channel  60  (which corresponds to a channel radius, channel diameter, and/or cross-sectional area of the channel) at the first end is less than a channel width of each fluid output channel  60  at the second end. Therefore, it may be appreciated that each respective fluid output channel  60  may be described as being tapered from the second end to the first end. 
       FIG.  5    provides a block diagram that illustrates some components of an example fluid ejection device  200 . In this example, the fluid ejection device  200  comprises a fluid ejection die  201  that includes a substrate  202  and a nozzle layer  203 . Furthermore, the fluid ejection device  200  comprises a molded panel  204  that may enclose portions of the fluid ejection die  201  and support the fluid ejection die  201 . In some examples, the nozzle layer  203 , substrate  202 , and molded panel may be composed of different materials. For example, the nozzle layer  203  may be formed of a polymer material; the substrate  202  may be formed of silicon; and the molded panel may be formed of an epoxy material. In some examples a top surface of the fluid ejection device  200  may be composed of a top surface of the nozzle layer  203  and a top surface of the molded panel  204 , where the top surface of the fluid ejection device  200  may be approximately planar. 
     The example die  201  includes fluid input holes  206  and fluid output holes  208  formed through the substrate layer  202 . Furthermore, the example die  201  comprises ejection nozzles  210  formed through the nozzle layer  203  As described with regard to other examples, the fluid ejection die  201  further includes a respective ejection chamber  212  formed in the substrate  202  and/or nozzle layer  203  adjacent to and fluidly connected with each respective nozzle  210 . A respective fluid output channel  214  fluidly connects each respective ejection chamber  212  to a fluid output hole  208 . While not shown in this example, it will be appreciated that the ejection die  200  may comprise a fluid ejector disposed in each respective ejection chamber  212  to eject fluid drops out of the ejection chamber  212  via the respective ejection nozzle  210 . Furthermore, the example fluid ejection die  200  may comprise a fluid pump disposed in each fluid output channel  214  to pump fluid from the respective ejection chamber  212  to the respective fluid output hole  208 . 
     In addition, the example fluid ejection die  200  comprises a fluid circulation rib  220 . As shown, the fluid circulation rib  220  extends in a plane that is generally orthogonal to a plane in which the fluid output channels  214  are arranged. The molded panel  204  and the substrate  202  may have a fluid slot  224  formed therethrough and fluidly connected to the fluid input holes  206  and the fluid output holes  208 . As shown in the example, each fluid circulation rib  220  extends into the fluid slot  224  a distance that may be described as a fluid circulation rib height  226 . In some examples, the fluid circulation rib height  226  may correspond to a fluid slot depth  230 . For example, the fluid circulation rib height  226  may be approximately 50% the fluid slot depth  230 . In other examples, the fluid circulation rib height  226  may be approximately 25% the fluid slot depth  230 . In some examples, the fluid circulation rib height  226  may be in a range of approximately 5% of the fluid slot depth  230  to approximately 90% of the fluid slot depth  230 . 
     In  FIG.  5   , a general fluid flow direction  240  is illustrated with dashed arrows. Notably, fluid may flow into the ejection chambers  212  from the fluid slot  224  via the fluid input holes  206 . As discussed previously, fluid may be ejected from the ejection chambers  212  via the respective nozzles  210 , or fluid may be pumped from the ejection chambers  212  out of the fluid output holes  208  via the fluid output channels  214 . In this example, fluid may be pumped out of the fluid output holes  208  back into the fluid slot  224 , where the respective fluid circulation rib  220  may inhibit flow of output fluid back into the fluid input holes  206  by providing a barrier therebetween. 
       FIG.  6    illustrates an example fluid ejection device  300  comprising a fluid ejection die  302 , a molded panel  304  and a carrier  306 . In this example, the fluid ejection die  302  is at least partially embedded in and at least partially enclosed by the molded panel  304 . The molded panel may be coupled to the carrier  306  with an adhesive  308 . As shown in this example, a fluid slot  310  may be formed through the carrier  306 , adhesive  308 , and molded panel  304 . The fluid slot is fluidly connected to a fluid input hole  312  and a fluid output hole  314  of the fluid ejection die  302 . The fluid input hole  312  of the fluid ejection die  302  is fluidly connected to an ejection chamber  314 . The ejection chamber  314  is fluidly connected to a nozzle  316  through which drops of fluid may be ejected. In addition, the ejection chamber  314  is fluidly connected to a fluid output channel  318 . In turn, the fluid output channel  318  is fluidly connected to the fluid output hole  314 . As described in previous examples, fluid of the ejection chamber may be pumped from the ejection chamber  314  back into the fluid slot  310  through the fluid output channel  318  and the fluid output hole  314 . 
     Turning to  FIG.  7   , a flowchart  400  is provided that illustrates an example sequence of operations that may be performed by an example fluid ejection device and/or a fluid ejection die thereof. As discussed with regard to previous examples, fluid may be ejected from an ejection chamber via an ejection nozzle with a fluid ejector (block  402 ). Asynchronous with ejection of fluid with the fluid ejector, fluid may be pumped from the ejection chamber out of a fluid outlet hole via a fluid output channel with a fluid pump (block  404 ). Therefore, it will be appreciated that in examples similar to the example of  FIG.  7   , operation of the fluid ejector and the fluid pump may be asynchronous—i.e. not concurrent. 
     Accordingly, examples provided herein may provide a fluid ejection die including a fluid input hole fluidly connected to an ejection chamber. The ejection chamber may be adjacent to and fluidly connected to an ejection nozzle such that fluid may be ejected out of the ejection chamber via the ejection nozzle. In addition, the ejection chamber may be fluidly connected to a fluid output channel, and the fluid output channel may be fluidly connected to a fluid output hole. Fluid may be pumped from the ejection chamber out of the fluid output hole via the fluid output channel to thereby facilitate circulation of fluid. As will be appreciated, circulation of fluid therewith may reduce particulate settling in the ejection chamber. In addition, circulation of fluid therewith may facilitate thermal cooling of components and surfaces proximate the ejection chamber. 
     The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the description. Therefore, the foregoing examples provided in the figures and described herein should not be construed as limiting of the scope of the disclosure, which is defined in the Claims.