Patent Publication Number: US-2021187957-A1

Title: Fluid ejection assemblies

Description:
BACKGROUND 
     A fluid ejection die, such as a printhead die in an inkjet printing system, may use thermal resistors or piezoelectric material membranes as actuators within fluidic chambers to eject fluid drops (e.g., ink) from nozzles, such that properly sequenced ejection of ink drops from the nozzles causes characters or other images to be printed on a print medium as the printhead die and the print medium move relative to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating an example of a fluid ejection device. 
         FIG. 2  is a block diagram illustrating an example of an inkjet printing system including an example of a fluid ejection device. 
         FIG. 3  is a bottom perspective view illustrating an example of a fluid ejection device. 
         FIG. 4  is a top perspective view illustrating an example of the fluid ejection device of  FIG. 3  including an example of a fluid ejection assembly and an example of a removable fluid supply for the fluid ejection assembly. 
         FIG. 5  is an exploded perspective view illustrating an example of the fluid ejection device of  FIG. 4 . 
         FIG. 6  is an exploded perspective view illustrating an example of the removable fluid supply of  FIGS. 4 and 5 . 
         FIGS. 7 a , 7 b    are cross-sectional views illustrating an example of the fluid ejection device of  FIG. 4  including an example of the removable fluid supply in an uncompressed state and a compressed state, respectively. 
         FIG. 8  is a flow diagram illustrating an example of a method of supplying fluid for a fluid ejection assembly. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. 
     As illustrated in the example of  FIG. 1 , the present disclosure provides a fluid ejection assembly  10 . In one implementation, fluid ejection assembly  10  includes a fluid ejection die  12 , and a body  14  supporting fluid ejection die  12 , with body  14  having a fluid chamber  15  communicated with fluid ejection die  12  and including a receptacle  16  to receive a removable fluid supply  20 , as represented by arrow  21 , with receptacle  16  having a fluid port  17  communicated with fluid chamber  15  through body  14 , as represented by arrow  18 . 
       FIG. 2  illustrates an example of an inkjet printing system  100  including an example of a fluid ejection device, as disclosed herein. Inkjet printing system  100  includes a printhead assembly  102 , as an example of a fluid ejection assembly, a fluid (ink) supply assembly  104 , a mounting assembly  106 , a media transport assembly  108 , an electronic controller  110 , and a service assembly  112 . 
     Printhead assembly  102  includes at least one printhead die  114 , as an example of a fluid ejection die, that ejects drops of fluid (ink) through a plurality of orifices or nozzles  116  toward a print medium  118  so as to print on print media  118 . Nozzles  116  are typically arranged in one or more columns or arrays such that properly sequenced ejection of fluid (ink) from nozzles  116  causes characters, symbols, and/or other graphics or images to be printed on print media  118  as printhead assembly  102  and print media  118  are moved relative to each other. Print media  118  can be any type of suitable sheet or roll material, such as paper, card stock, transparencies, Mylar, and the like, and may include rigid or semi-rigid material, such as cardboard or other panels. 
     Fluid (ink) supply assembly  104  supplies fluid (ink) to printhead assembly  102  such that fluid flows from fluid (ink) supply assembly  104  to printhead assembly  102 . In one example, fluid (ink) supply assembly  104  is supported by printhead assembly  102  and is removable from printhead assembly  102 , as represented, for example, by arrow  124 , such that fluid (ink) supply assembly  104  may be replaced. 
     Mounting assembly  106  positions printhead assembly  102  relative to media transport assembly  108 , and media transport assembly  108  positions print media  118  relative to printhead assembly  102 . Thus, a print zone  120  is defined adjacent to nozzles  116  in an area between printhead assembly  102  and print media  118 . In one example, printhead assembly  102  is a scanning type printhead assembly. As such, mounting assembly  106  includes a carriage for moving printhead assembly  102  relative to media transport assembly  108  to scan print media  118 . In another example, printhead assembly  102  is a non-scanning type printhead assembly. As such, mounting assembly  106  fixes printhead assembly  102  at a prescribed position relative to media transport assembly  108 . 
     Electronic controller  110  typically includes a processor, firmware, software, one or more memory components including volatile and non-volatile memory components, and other printer electronics for communicating with and controlling printhead assembly  102 , mounting assembly  106 , media transport assembly  108 , and service assembly  112 . Electronic controller  110  receives data  122  from a host system, such as a computer, and temporarily stores data  122  in a memory. Data  122  may be received via an electronic, infrared, optical, or other information transfer path. Data  122  represents, for example, a document and/or file to be printed. As such, data  122  forms a print job for inkjet printing system  100  and includes one or more print job commands and/or command parameters. 
     In one example, electronic controller  110  controls printhead assembly  102  for ejection of fluid (ink) drops from nozzles  116 . Thus, electronic controller  110  defines a pattern of ejected fluid (ink) drops which form characters, symbols, and/or other graphics or images on print media  118 . The pattern of ejected fluid (ink) drops is determined by the print job commands and/or command parameters. 
     Service assembly  112  provides for wiping, capping, spitting, and/or priming of printhead assembly  102  in order to maintain a functionality of printhead assembly  102 , including, more specifically, nozzles  116  of printhead die  114 . For example, service assembly  112  may include a rubber blade or wiper which periodically contacts and passes over printhead assembly  102  to wipe and clean nozzles  116  of excess ink. In addition, service assembly  112  may include a cap which covers printhead assembly  102  to protect nozzles  116  from drying out during periods of non-use. In addition, service assembly  112  may include a spittoon or absorbent material into which printhead assembly  102  ejects (i.e., spits or purges) ink to insure that fluid (ink) supply assembly  104  maintains an appropriate level of pressure and fluidity, and insure that nozzles  116  do not clog or weep. Functions of service assembly  112  may include relative motion between service assembly  112  and printhead assembly  102 . 
     Printhead assembly  102  includes one (i.e., a single) printhead die  114  or more than one (i.e., multiple) printhead die  114 . In one example, printhead assembly  102  is a wide-array or multi-head printhead assembly. In one implementation of a wide-array assembly, printhead assembly  102  includes a carrier that carries a plurality of printhead dies  114 , provides electrical communication between printhead dies  114  and electronic controller  110 , and provides fluidic communication between printhead dies  114  and fluid (ink) supply assembly  104 . 
     In one example, inkjet printing system  100  is a drop-on-demand thermal inkjet printing system wherein printhead assembly  102  includes a thermal inkjet (TIJ) printhead that implements a thermal resistor as a drop ejecting element to vaporize fluid (ink) in a fluid chamber and create bubbles that force fluid (ink) drops out of nozzles  116 . In another example, inkjet printing system  100  is a drop-on-demand piezoelectric inkjet printing system wherein printhead assembly  102  includes a piezoelectric inkjet (PIJ) printhead that implements a piezoelectric actuator as a drop ejecting element to generate pressure pulses that force fluid (ink) drops out of nozzles  116 . 
       FIGS. 3 and 4  are bottom and top perspective views, respectively, illustrating an example of a fluid ejection device  200  in accordance with the present disclosure. In the illustrated example, fluid ejection device  200  includes a fluid ejection assembly  210 , as an example of printhead assembly  102  ( FIG. 2 ), and a fluid supply  250 , as an example of fluid (ink) supply assembly  104  ( FIG. 2 ). As disclosed herein, fluid supply  250  is support by and removable from fluid ejection assembly  210 . 
     In one example, fluid ejection assembly  210  includes a housing or body  220 , a fluid ejection die  230 , and an electrical circuit  240  such that fluid ejection die  230  is supported by body  220  and electrically coupled with electrical circuit  240 . In one implementation, fluid ejection die  230 , as an example of printhead die  114  ( FIG. 2 ), includes a drop-on-demand thermal inkjet (TIJ) printhead, as described above. In another implementation, fluid ejection die  230 , as an example of printhead die  114  ( FIG. 2 ), includes a drop-on-demand piezoelectric inkjet (PIJ) printhead, as described above. In either example, fluid ejection die  230  includes orifices or nozzles, such as orifices or nozzles  116  ( FIG. 2 ), through which drops of fluid (ink) are ejected, as described above. In one example, fluid ejection die  230  includes a thin-film structure formed on a substrate with the substrate formed, for example, of silicon, glass, or a stable polymer, and the thin-film structure including conductive, passivation or insulation layers. 
     In one example, body  220  supports fluid ejection die  230  and electrical circuit  240  such that electrical circuit  240  facilitates communication of electrical signals between an electronic controller, such as electronic controller  110  ( FIG. 2 ), and fluid ejection die  230  for controlling and/or monitoring operation of fluid ejection die  230 . 
     In one example, electrical circuit  240  includes a plurality of electrical contacts  242  and a plurality of conductive paths which extend between and provide electrical connection between electrical contacts  242  and fluid ejection die  230 . Electrical contacts  242  provide points for electrical connection to fluid ejection assembly  210  and, more specifically, fluid ejection die  230 . As such, electrical contacts  242  facilitate communication of power, ground, and/or data signals with fluid ejection die  230 . In one implementation, electrical circuit  240  is supported by body  220  such that electrical contacts  242  are provided at end of body  220 . 
     In one example, electrical circuit  240  is a flexible electrical circuit with conductive paths formed in or on a flexible base material. The flexible base material may include, for example, a polyimide or other flexible polymer material (e.g., polyester, poly-methyl-methacrylate), and the conductive paths may be formed of copper, gold, or other conductive material. 
     In one implementation, fluid ejection assembly  210  includes multiple fluid ejection die  230  supported by body  220  such that fluid ejection assembly  210  provides a wide-array (e.g., page-wide array) printhead assembly. As a wide-array or multi-head printhead assembly, the multiple fluid ejection die  230  of fluid ejection assembly  210  are arranged and aligned in one or more staggered or overlapping rows such that a fluid ejection die  230  in one row overlaps at least one fluid ejection die  230  in another row. As such, fluid ejection assembly  210  may span a nominal page width or a width shorter or longer than a nominal page width. 
     In one example, body  220  supports fluid supply  250  such that fluid supply  250  communicates with and supplies fluid (ink) to fluid ejection die  230 . More specifically, in one example, body  220  of fluid ejection assembly  210  includes a tub or receptacle  222  for receiving and supporting fluid supply  250 . In one implementation, body  220  includes a lid or cover  224  with tub or receptacle  222  being formed or provided in cover  224 . In one example, cover  224  is provided on a side of body  220  opposite of fluid ejection die  230  and receptacle  222  is open in a direction opposite a direction of ejection of drops of fluid from fluid ejection die  230  (see, for example,  FIGS. 1, 7   b ). As such, fluid supply  250  is inserted into receptacle  222  in a direction substantially perpendicular to cover  224 , as represented by arrow  251 . Accordingly, fluid supply  250  is inserted into receptacle  222  in a direction the same as a direction of ejection of drops of fluid from fluid ejection die  230  (see, for example,  FIG. 7 b   ). 
     In one implementation, as illustrated in the example of  FIG. 4 , fluid supply  250  includes a plurality of fluid supply pods or blisters  252  and fluid ejection assembly  210  includes a plurality of receptacles  222  for separately receiving and supporting individual fluid supply pods or blisters  252 . 
     In one example, fluid supply pods or blisters  252  of fluid supply  250  may include different types or colors of fluid. As such, fluid ejection die  230  may be supplied with more than one type or color of fluid (e.g., fluids of different dyes, pigments, constituents, substances, agents, reactants, reagents, or colors) and may include a column (or columns) of orifices or nozzles for each type or color of fluid. In some examples, fluid supply pods or blisters  252  of fluid supply  250  may include different colors of fluid such that fluid ejection die  230  may eject different colors of fluid (e.g., cyan, magenta, yellow, and black ink). In other examples, fluid supply pods or blisters  252  of fluid supply  250  may include different types of fluid such that fluid ejection die  230  may eject at least two types of fluid. For example, fluid ejection die  230  may correspond to a lab-on-a-chip device, where a first fluid may be a reagent, and a second fluid may be a solution including test material therein. 
     Although illustrated as including three fluid supply pods or blisters  252 , fluid supply  250  may include any number of fluid supply pods or blisters  252  (for example one, two, three, or more). 
       FIG. 5  is an exploded perspective view illustrating an example of fluid ejection device  200 . In the illustrated example, body  220  of fluid ejection assembly  210  includes a fluid cavity or fluid chamber  226  fluidically communicated with fluid ejection die  230  (see, for example,  FIGS. 7 a , 7 b   ) such that cover  224  of body  220  fits over and seals fluid chamber  226 . In one implementation, fluid chamber  226  includes a plurality of fluid chambers  226  with tubs or receptacles  222  of cover  224  extending into and fitting within a respective fluid chamber  226 . 
     In one implementation, an absorbent material  270  (e.g., foam material) is positioned within each fluid chamber  226  to provide back pressure to fluid ejection die  230  during ejection of fluid therefrom. In addition, in one implementation, a vent  225  corresponding to each fluid chamber  226  is provided in cover  224 . As such, vent  225  allows air to pass into and out of fluid chamber  226 . In one example, a permeable seal  272  (e.g., permeable tape) is provided over vents  225  such that air is allowed to pass through permeable seal  272  while fluid is prevented from passing through permeable seal  272 . In one example, vents  225  include a labyrinth or serpentine structure or channel to increase the length of and thereby slow the rate of evaporation through vents  225 . In one implementation, the labyrinth or serpentine structure or channel is formed in a top surface of cover  224  such that an end of the labyrinth or serpentine structure or channel extends past an edge of permeable seal  272 . 
     In one example, a fluid interconnect seal  274  (e.g., O-ring) is provided to provide a fluid-tight seal between fluid supply pods or blisters  252  of fluid supply  250  and tubs or receptacles  222  of cover  224  of body  220 . 
       FIG. 6  is an exploded perspective view illustrating an example of fluid supply  250 . In the illustrated example, each fluid supply pod or blister  252  includes a container or housing  254  forming a fluid reservoir  255 , a compressible member  256  (e.g., foam material) disposed within fluid reservoir  255  in housing  254 , and a rigid member or press plate  258  disposed within fluid reservoir  255  in housing  254 . In one implementation, press plate  258  is in contact with compressible member  256  and is moved or pressed against compressible member  256  to compress compressible member  256  and force fluid from fluid reservoir  255  of fluid supply pod or blister  252 , as described below. 
     In one example, fluid supply  250  includes a cap or lid  260 . In one implementation, lid  260  is common to multiple fluid supply pods or blisters  252 . In other implementations, each fluid supply pod or blister  252  includes an individual lid  260 . In one example, lid  260  includes a port  262  corresponding to each fluid supply pod or blister  252 . 
     In one example, each fluid supply pod or blister  252  includes a plunger seal  264  slidingly fit in a respective port  262 . As such, plunger seal  264  seals a respective port  262  and is depressed or pressed inward to press against and move press plate  258  to compress compressible member  256 , as described below. 
       FIGS. 7 a , 7 b    are cross-sectional views illustrating an example of fluid ejection device  200  including an example of fluid ejection assembly  210  and an example of fluid supply  250  with fluid supply  250  in an uncompressed state and a compressed state, respectively. As illustrated in the example of  FIGS. 7 a , 7 b   , absorbent material  270  is positioned within fluid chamber  226  of body  220 , and cover  224  is secured to body  220 . As such, vent  225  communicates with fluid chamber  226  and permeable seal  272  covers vent  225  such that air is allowed to pass through vent  225  to and from fluid chamber  226 . 
     As described below, fluid chamber  226  is supplied with fluid from fluid supply  250  such that fluid within fluid chamber  226  is communicated with fluid ejection die  230  as supported by body  220 . In one example, body  220  has one or multiple fluid passages  221  formed therein which communicate with fluid chamber  226  and fluid ejection die  230  such that fluid from fluid chamber  226  is communicated with fluid ejection die  230  through body  220 . In one example, each fluid passage  221  communicates with a different fluid chamber  226  such that fluid from a respective fluid chamber  226  is communicated with fluid ejection die  230 . In one implementation, a filter  276  is provided within a fluid path between fluid chamber  226  and fluid passage or passages  221  to filter fluid supplied to fluid ejection die  230  through fluid passage or passages  221 . 
     As illustrated in the example of  FIG. 7 a   , fluid supply  250  including, more specifically, fluid supply pod or blister  252  (with fluid therein) is inserted into or positioned within tub or receptacle  222  of body  220 . In one example, when fluid supply pod or blister  252  is inserted into or positioned within tub or receptacle  222 , a fluid port  253  of housing  254  communicates with a fluid port  223  of tub or receptacle  222  to form a fluid interconnect between fluid supply  250 , namely, fluid reservoir  255  of fluid supply  250 , and body  220 , namely, tub or receptacle  222  of body  220 . In one implementation, fluid interconnect seal  274  is positioned between fluid supply pod or blister  252  and tub or receptacle  222  to provide a fluid-tight seal between fluid supply pod or blister  252  and tub or receptacle  222 . 
     In one example, cover  224  of body  220  includes a fluid path  228  communicated between fluid port  223  and fluid chamber  226  such that fluid from fluid supply  250  is supplied to fluid chamber  226  through fluid port  253 , fluid port  223 , and fluid path  228 . In one implementation, fluid path  228  is formed by a groove or fluid channel  229  in cover  224 , namely, in a portion of cover  224  forming tub or receptacle  222 , and a fluid routing film  278  (see also  FIG. 5 ) secured to cover  224  over fluid channel  229  such that one end of fluid channel  229  is communicated with fluid port  223  and an opposite end of fluid channel  229  is open to fluid chamber  226 . 
     As illustrated in the example of  FIG. 7 a   , fluid supply  250  is in an uncompressed state, with compressible member  256  positioned within fluid reservoir  255  of housing  254 , press plate  258  in contact with compressible member  256 , and plunger seal  264  fit within port  262  of lid  260 . In the uncompressed state, plunger seal  264  is positioned within port  262  of lid  260  such that compressible member  256  pushes press plate  258  toward or against plunger seal  264  and a lip  263  of port  262 . 
     As illustrated in the example of  FIG. 7 b   , fluid supply  250  is in a compressed state. In the compressed state, plunger seal  264  is depressed or pressed into housing  254  relative to lid  260  such that press plate  258  is moved and pressed against compressible member  256  whereby compressible member  256  is compressed. In one example, when plunger seal  264  is depressed, a vent  261  within port  262  is opened such that air may pass into and out of fluid supply  250 . In one example, plunger seal  264  is depressed or pressed into housing  254  by a pin or projection provided, for example, on a latch or case closure (not shown) for fluid ejection assembly  210 . 
     As illustrated in the example of  FIG. 7 b   , when compressible member  256  is compressed, fluid from fluid supply  250 , namely, fluid from fluid reservoir  255  of fluid supply  250 , is forced through fluid port  253 , fluid port  223 , and fluid path  228  to fluid chamber  226 , as represented by arrow  280 . As such, fluid within fluid chamber  226  is supplied to fluid ejection die  230  (e.g., through filter  276  and fluid passage  221 ) for ejection from fluid ejection die  230 . 
     In one example, as illustrated in  FIG. 7 b   , to compress compressible member  256  and force fluid to fluid chamber  226 , plunger seal  264  is depressed in a direction indicated by arrow  282 . In addition, during operation of fluid ejection device  200 , drops of fluid are ejected from fluid ejection die  230  in a direction indicated by arrow  284 . As such, plunger seal  264  is depressed in a direction the same as a direction of ejection of drops of fluid from fluid ejection die  230  (e.g., downward in the illustrated example). 
       FIG. 8  is a flow diagram illustrating an example of a method  400  of supplying fluid for a fluid ejection assembly, such as fluid ejection assembly  210  of fluid ejection device  200  as illustrated, for example, in  FIGS. 3, 4, 5 . At  402 , method  400  includes supporting a removable fluid supply with the fluid ejection assembly, such as supporting removable fluid supply  250  with fluid ejection assembly  210 , as illustrated, for example, in  FIGS. 4, 5, 7   a ,  7   b . And, at  404 , method  400  includes compressing a compressible member within the removable fluid supply to force fluid from the removable fluid supply to a fluid chamber communicated with a fluid ejection die of the fluid ejection assembly, such as compressing compressible member  256  within removable fluid supply  250  to force fluid from removable fluid supply  250  to fluid chamber  226  communicated with fluid ejection die  230  of fluid ejection assembly  210 , as illustrated, for example, in  FIG. 7   b.    
     In one example, supporting the removable fluid supply, at  402 , includes removably supporting removable fluid supply  250  within receptacle  222  of fluid ejection assembly  210  and fluidically communicating removable fluid supply  250  with fluid port  223  of receptacle  222 , as illustrated, for example, in  FIG. 7   a.    
     In one example, compressing the compressible member, at  404 , includes pressing plunger seal  264  of removable fluid supply  250  against press plate  258  within removable fluid supply  250  and pressing press plate  258  against compressible member  256 , as illustrated, for example, in  FIG. 7   b.    
     By removably supporting fluid supply  250  on fluid ejection assembly  210 , as disclosed herein, an integrated fluid ejection device  200  with a replaceable fluid supply and compact or reduced form factor may be achieved. As such, fluid ejection device  200 , as disclosed herein, may be implemented, for example, in a pocket-sized printer. 
     Example fluid ejection devices, 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. 
     Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.