Abstract:
A liquid drop ejector is provided. The ejector includes a liquid chamber and a liquid supply. Portions of the liquid chamber define a nozzle bore. A liquid supply passageway is positioned between the liquid chamber and the liquid supply. The liquid supply passageway is in fluid communication with the liquid chamber and the liquid supply. A plurality of pillars is suspended in the liquid supply passageway. A wall of the liquid chamber can extend to the liquid supply passageway. A center pillar can also be included with a portion of the center pillar being positioned in the liquid chamber and another portion of the center pillar being positioned in the liquid supply passageway.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to liquid ejectors and, more specifically, to liquid ejectors having internal filters.  
       BACKGROUND OF THE INVENTION  
       [0002]     Inkjet printing systems are extensively used throughout the world for the reproduction and generation of text and images. Inkjet printing systems eject liquids in the form of droplets that are deposited upon a suitable receiver in an image-wise fashion. Common uses include the printing of text and the reproduction of images. Liquids that are ejected can be inks or pigments and the applications vary widely but include printers, plotters, facsimile machines and copiers. For purposes of convenience the concepts of this invention are discussed in the terms of a thermal inkjet printer that employ one or more supplies or reservoirs of liquids to be deposited upon a medium such as paper.  
         [0003]     Ink is supplied to a liquid ejector mechanism, also known as a print head, through a supply channel and into a chamber of the liquid ejector that contains thermal resistors as firing mechanisms. Sending an electrical current through the thermal resistors causes the heating of the resistor and forces the formation of a vapor bubble within the chamber. The expanding vapor bubble within the chamber then causes an ink droplet to be forced out of an orifice situated upon the chamber. As ink is expelled from the orifice, energy is removed from the thermal resistor, the bubble collapses and ink refills the chamber to begin another sequence.  
         [0004]     As the need for ejection speed increases, so does the optimization of the operation of the chambers to maximize ink flow. Additionally the throughput requirement also means the need for more chambers and ejection orifices. It is a constant engineering challenge to maintain the proper balance that is required to enhance inkjet system performance.  
         [0005]     In typical inkjet printing systems, a filter element is generally placed at the inlet to the supply port of an inkjet chamber. Reference U.S. Pat. No. 6,582,064 by Cruz-Uribe et al., of Hewlett-Packard Company, Houston Tex., that describes integrated fluid filters constructed from stacks of stacked thin film layers with openings that function as filters. Reference also U.S. Pat. No. 6,502,927 by Nozawa of Canon Kabushiki Kaisha of Tokyo, Japan that describes pillars as filters. These filters have several functions such as that of an ink conduit and function to preclude the delivery of impurities, debris and air bubbles that could enter the chamber of a liquid ejector and cause clogging of the chamber or orifice thus rendering a firing chamber inoperable.  
         [0006]     Chambers and geometries are commonly configured to enhance operational performance. Reference U.S. Pat. No. 6,478,410 by Prasad, et al. of Hewlett-Packard Company, Palo Alto, Calif. that attempts to balance a higher inkjet droplet generator density with structures that attempt to achieve proper control of ink flow. Reference also U.S. Pat. No. 6,601,945 by Kitakami of Canon Kabushiki Kaisha, of Tokyo, Japan that attempts to correct for image quality by using a “windshield liquid droplet” that prevents the displacement upon a recording medium of the ink droplet discharged in a high density “full discharge” mode even when the ink droplet has a fine volume.  
         [0007]     U.S. Pat. No. 5,734,399 by Weber et al. of Hewlett-Packard Company of Palo Alto Calif. discloses shaped barrier geometries that prevent stray particles from reaching ink feed channels. The barriers are configured to have a plurality of inner barrier islands each associated with a chamber and a particular heater resistor. These barrier islands commonly occupy a common area between the ink firing chamber and the ink plenum, commonly known as an ink supply.  
         [0008]     U.S. Pat. No. 6,540,335 by Touge et al. of Canon Kabushiki Kaisha of Tokyo, Japan discloses an ink jet printhead for preventing problems that are caused by air bubbles caught in the printhead. Bubbles are left in the printhead after liquid discharge, and the invention enables the ejection of droplets with high reliability by controlling the residual bubble.  
         [0009]     U.S. Pat. No. 6,137,510 by Sato et al. of Canon Kabushiki Kaisha of Tokyo, Japan discloses the additions of pluralities of ribs that provide increased mechanical strength to the orifice plate and additionally reduce the detrimental effects of air bubbles. These ribs reduce the effects of these retained bubbles thereby achieving reliable ink droplet discharge.  
         [0010]     Lastly, U.S. Pat. No. 6,158,843 by Murthy et al. of Lexmark International of Lexington, Ky., discloses pillars extending vertically into the firing chamber but not into the common area.  
         [0011]     Filter elements also play an important role in the hydraulic interactions between neighboring nozzles. As the inkjet recording process has matured over the years, so too has the demand for ink jet recording heads to achieve higher recording speeds. Pluralities of nozzles that reside adjacent one another within a given printing system have to be addressed in relationship to one another within a short period of time. As these blocks of nozzles are fired, the stability within adjacent unfired or recently fired nozzles is negatively affected, thereby substantially increasing the interaction between adjacent nozzles. The generation of this adverse hydraulics, coupled with the internal filtering elements, affects the chamber refill time and limits how quickly a particular chamber can be ready to be reused. Since the chamber refill time is directly proportional to how quickly a chamber can be fired, the matching of filter properties is important. Properties that improve the refill efficiencies and additionally satisfy the need to filter impurities such as dust is critical, and most prior art suggests that attempts at doing both well have not been entirely successful.  
       SUMMARY OF THE INVENTION  
       [0012]     According to one feature of the present invention, a liquid drop ejector includes a liquid chamber and a liquid supply. Portions of the liquid chamber define a nozzle bore. A liquid supply passageway is positioned between the liquid chamber and the liquid supply and is in fluid communication with the liquid chamber and the liquid supply. A plurality of pillars is suspended in the liquid supply passageway.  
         [0013]     According to another feature of the present invention, a liquid drop ejector includes a plurality of liquid chambers with portions of each of the plurality of liquid chambers defining a nozzle bore. Other portions of each of the plurality of liquid chambers define a wall having a length located between adjacent liquid chambers. A liquid supply passageway is in fluid communication with each of the plurality of liquid chambers. The length of the wall extends into the liquid supply passageway.  
         [0014]     According to another feature of the present invention, a liquid drop ejector includes a liquid chamber, a liquid supply, and a center pillar. Portions of the liquid chamber define a nozzle bore. A liquid supply passageway is positioned between the liquid chamber and the liquid supply and is in fluid communication with the liquid chamber and the liquid supply. A portion of the center pillar is positioned in the liquid chamber and another portion of the center pillar is positioned in the liquid supply passageway. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:  
         [0016]      FIG. 1A  is a partial planar view of an internal structure of a prior art liquid drop ejector.  
         [0017]      FIG. 1B  is a second partial planar view of an internal structure of a prior art liquid drop ejector.  
         [0018]      FIG. 1C  is a cross-sectional side view of the internal structure of the prior art liquid drop ejector of  FIG. 1B  taken along line  1 C- 1 C.  
         [0019]      FIG. 1D  is a partial planar view of the liquid drop ejector of the present invention showing a cross-section along line  FIG. 2 - FIG. 2 .  
         [0020]      FIG. 1E  is another partial planar view of the liquid drop ejector of the present invention showing a cross-section along line  FIG. 2 - FIG. 2 .  
         [0021]      FIG. 2  is a cross-sectioned side view of the internal structure of the liquid drop ejector detailed in  FIG. 1D .  
         [0022]      FIG. 3  is a side view of the liquid drop ejector of the present invention detailing a plurality of pillars suspended from the wall of the liquid supply passageway.  
         [0023]      FIG. 4  is a side view of the liquid drop ejector of the present invention detailing a second placement of the pillars suspended from the wall of the liquid supply passageway.  
         [0024]      FIG. 5  is a side view of the liquid drop ejector of the present invention detailing another placement of the pillars suspended from the wall of the liquid supply passageway, the drop ejector comprising a nozzle plate.  
         [0025]      FIG. 6  is a partial planar view of the internal structure of the liquid drop ejector of the present invention, showing a center pillar associated with the liquid drop ejector.  
         [0026]      FIG. 7  is an alternate cross-sectional side view of the internal structure of the liquid drop ejector detailed in  FIG. 6 .  
         [0027]      FIG. 8  is cross-sectional side view of a second internal configuration of the liquid drop ejector detailed in  FIG. 7 .  
         [0028]      FIG. 9  is a partial planar view of the internal structure of the liquid drop ejector of the present invention.  
         [0029]      FIG. 10  is a cross-sectioned side view of the internal structure of the liquid drop ejector detailed in  FIG. 9 .  
         [0030]      FIG. 11  is a partial planar view of the internal structure of the liquid drop ejector of the present invention detailing pillars suspended in the liquid passageway.  
         [0031]      FIG. 12  is a cross-sectioned side view of the internal structure of the liquid drop ejector shown in  FIG. 11  detailing pillars suspended in the liquid passageway.  
         [0032]      FIG. 13  is a side view of the liquid drop ejector of the present invention detailing pillars suspended from the wall of the liquid supply passageway.  
         [0033]      FIG. 14  is a side view of the liquid drop ejector of the present invention detailing a second placement of the pillars suspended from the wall of the liquid supply passageway.  
         [0034]      FIG. 15  is a side view of the liquid drop ejector of the present invention detailing the placement of the pillars upon the nozzle plate of a drop ejector, or upon walls that can be parallel or perpendicular to the nozzle bore.  
         [0035]      FIG. 16  is a partial planar view of the internal structure of the liquid drop ejector of the present invention, showing the suspended pillars along with a center pillar associated with the liquid drop ejector.  
         [0036]      FIG. 17  is an alternate cross-sectional side view of the internal structure of the liquid drop ejector detailed in  FIG. 16 .  
         [0037]      FIG. 18  is cross-sectional side view of a second internal configuration of the liquid drop ejector detailed in  FIG. 17 .  
         [0038]      FIG. 19  is a partial planar view of the internal structure of the liquid drop ejector of the present invention.  
         [0039]      FIG. 20  is a cross-sectioned side view of the internal structure of the liquid drop ejector detailed in  FIG. 19 .  
         [0040]      FIG. 21  is a second cross-sectioned side view of an alternate structure of the liquid drop ejector detailed in  FIG. 20 .  
         [0041]      FIG. 22  is cross-sectional side view of another internal configuration of the liquid drop ejector detailed in  FIG. 21  that adds pillars suspended from the wall of the liquid supply passageway.  
         [0042]      FIG. 23  is cross-sectional side view of another internal configuration of the liquid drop ejector detailed in  FIG. 22  that adds pillars attached to a first wall.  
         [0043]      FIG. 24  is cross-sectional side view of another internal configuration of the liquid drop ejector detailed in  FIG. 22  that adds pillars attached to a second wall.  
         [0044]      FIG. 25  is cross-sectional side view of another internal configuration of the liquid drop ejector wherein the drop ejector is comprised of a nozzle plate.  
         [0045]      FIG. 26  is a cross-sectional view of the liquid drop ejector of the present invention detailing a view where there is a drop forming mechanism associated with the liquid chamber.  
         [0046]      FIG. 27  is a cross-sectional view of the liquid drop ejector of the present invention detailing a view where there is a heater below the nozzle bore.  
         [0047]      FIG. 28  is a cross-sectional view of the liquid drop ejector of the present invention detailing a view where there is a heater adjacent the nozzle bore.  
         [0048]      FIG. 29  is a partial planar view of an internal structure of the liquid drop ejector of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0049]     The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.  
         [0050]     Referring to  FIG. 1A , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  (prior art). A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Chamber block  21 , is a feature that is used for over-damping the meniscus ringing within the liquid drop ejector  10 . Liquid  40  is supplied from the liquid supply  60  through a common area  50 , and flows past pillars  90  that are used to trap particles that could plug liquid chamber and/or nozzle bore  80  thus rendering a portion of the liquid drop ejector useless. It is commonplace for practitioners of the art to use pillars  90  for the purpose of filtering and support.  
         [0051]      FIG. 1B  is a partial planar view of a liquid drop ejector  10  (prior art). Block  30  is designed to prevent problems that are caused by air bubbles that are formed in the printhead. The liquid supply passageway  70  exists between the block  30  and the liquid chamber  20 . It is instructive to note that there is a lack of a common area  50  that is detailed in  FIG. 1A .  
         [0052]     Referring next to  FIG. 1C , shown is a cross-sectional view of the partial planar view detailed in  FIG. 1B . Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the whole length of the liquid drop ejector  10  (prior art). A liquid supply  60  exists for the supply of ink for the liquid drop ejector  10  (prior art).  
         [0053]      FIG. 1D  details a partial planar view of the liquid drop ejector  10  of the present invention. Heater  170  exists to eject a liquid  40  through the nozzle bore  80  of the liquid drop ejector  10 . Liquid chambers  20  exist by virtue of chamber walls  130  that serve to isolate the plurality of liquid chambers  20  physically from each other. In the case of the present invention, the plurality of pillars  90  is suspended within the liquid supply passageways  70 , and adjacent rows of liquid chambers  20  are isolated by the block  30 . In  FIG. 1D , more than one pillar  90  is positioned within the liquid supply passageway  70  so as to be associated with an individual liquid chamber  20 . Two pillars  90  are shown in  FIG. 1D  for illustrative purposes only. It should be understood that more than two pillars  90  can be positioned within the liquid supply passageway  70  and associated with an individual liquid chamber  20 .  
         [0054]     Other pillar  90  and liquid chamber  20  associations can occur depending on the contemplated application of the liquid drop ejector  10 . For example, and referring to  FIG. 1E , the plurality of pillars  90  is positioned within the liquid supply passageway  70  such that each pillar of the plurality of pillars  90  is associated with an individual liquid chamber  20 .  
         [0055]      FIG. 2  details a cross-sectional view of a liquid drop ejector  10  previously detailed in  FIG. 1D , and shows the suspension of the pillars  90  directly within the liquid supply passageway  70 , upon a wall  25  that is substantially perpendicular to the nozzle bore  80 . Note again, that the suspension of the pillars  90  within the fluid supply passageway  70 , allows a shorter liquid chamber  20  by moving the pillars  90  out of the prior art common area  50  ( FIG. 1A ) of the liquid drop ejector  10 . Moving the pillars  90  out of the prior art common area  50  frees up this space and allows for its complete removal. The removal of the prior art common area  50  allows the shortening of the liquid chamber  20 , thus reducing the distance that liquid  40  is required to flow thus reducing refill times while still preserving effective filtering of the liquid  40 .  
         [0056]     Referring now to  FIG. 3 , detailed is a cross-sectional view of a liquid drop ejector  10  of the present invention. The liquid supply passageway  70  is containment for fluid  40 . This being understood, the fluid supply passageway  70  has walls that are both perpendicular and parallel to the nozzle bore  80 . Referring again to  FIG. 3 , a plurality of pillars  90  is shown residing upon a first perpendicular wall of the fluid supply passageway  70 ; upon a wall  35  that is substantially parallel to the nozzle bore  80 . Next referring to  FIG. 4  pillars  90  are shown residing upon a second perpendicular wall of the fluid supply passageway  70 .  FIG. 2  details pillars  90  that reside upon a wall that is substantially parallel to the nozzle  80 .  
         [0057]     Referring now to  FIG. 5 , detailed is a cross-sectional view of a liquid drop ejector  10  of the present invention. In this diagram, a separate nozzle plate  100  is attached along the dashed line to form a roof for the liquid drop ejector  10 . Nozzle plate  100  also contains both the liquid supply chamber  20  and the liquid supply passageway  70 . Pillars  90  are shown suspended from the nozzle plate  100 . It should be understood at this time that pillars  90  can be suspended in the liquid supply passageway  70  both in a plane perpendicular to the nozzle bore  80  as in  FIG. 3 , and a plane parallel to the nozzle bore  80  as shown in  FIG. 2 .  
         [0058]     Referring to  FIG. 6 , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  of the present invention. A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the whole length of the liquid drop ejector  10 .  
         [0059]     Liquid  40  is supplied via a liquid supply passageways  70 , and flows past pillars  90  that are used to trap particles that could plug liquid chamber  20  and/or nozzle bore  80  thus rendering a portion of the liquid drop ejector useless. It is commonplace for practitioners of the art to use pillars  90  for the purpose of filtering and support. These pillars  90  exist in a prior art common area  50  ( FIG. 1A ) that exists between the liquid chamber  20  and the liquid supply passageway  70 . The placement of pillars  90  within the liquid supply passageway  70 , instead of the prior art common area  50  ( FIG. 1A ) produces significantly enhanced refill, while still preserving effective filtering. This suspension of pillars  90  directly within the liquid supply passageway  70 , as opposed to the prior art placement of these pillars  90  within the prior art common area  50  ( FIG. 1A ), allows for a shorter distance that the liquid  40  is required to flow to refill the liquid chamber  20 . Thus, the refilling time of the liquid chamber  20  of the liquid drop ejector  10  is substantially improved. Referring also to  FIG. 6 , there exists a center pillar  90   a  wherein a first portion of the center pillar  90   a  is positioned within the liquid chamber and wherein a second portion of the center pillar  90   a  is positioned within the liquid supply passageway  70 .  
         [0060]      FIG. 7  details a cross-sectional view of a liquid drop ejector  10  previously detailed in  FIG. 6 , and shows the suspension of the pillars  90  directly within the liquid supply passageway  70 . Note again that the suspension of the pillars  90  within the liquid supply passageway  70  allows a shorter liquid chamber  20  by moving the pillars  90  out of the prior art common area  50  ( FIG. 1A ) of the liquid drop ejector  10 . Referring also to  FIG. 7 , there exists a center pillar  90   a  wherein a first portion of the center pillar  90   a  is positioned within the liquid chamber  20  and wherein a second portion of the center pillar  90   a  is positioned within the liquid supply passageway  70 .  
         [0061]     Referring to  FIG. 8 , detailed is a center pillar  90   b  positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . Pillar  90   b  has a top and a bottom (two ends). The top end of the pillar  90   b  is attached to a first wall (or roof  110 ) of the liquid supply passageway  70 , and the bottom end is attached to a second wall (or floor  120 ) of the liquid supply passageway  70 . A first portion of the second end (bottom) of pillar  90   b  is positioned within the liquid chamber  20 , and a second portion of the second end (bottom) of pillar  90   b  is positioned within the liquid supply passageway  70 .  
         [0062]     Referring to  FIG. 9 , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  of the present invention. A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the whole length of the liquid drop ejector  10 .  
         [0063]     Liquid  40  is supplied via a liquid supply passageway  70  and is ultimately ejected through nozzle  80 . A chamber wall  130  exists as a separation between adjacent liquid chambers  20 . The length of the chamber wall  130  has been found to have a positive effect on crosstalk between adjacent liquid chambers  20 . The extension of this chamber wall  130  into and over the liquid supply passageway  70  minimizes cross communication, (also known as crosstalk) of fluids between the adjacent chambers  20 .  
         [0064]     It should be understood at this point that the main physical cause for crosstalk is the impulsive motion of the liquid due to the acceleration of the fluid interface with a vapor bubble during its generation and growth. Previous approaches to minimize this inter-nozzle coupling and subsequent interaction vary widely. One example is inertial decoupling where feed channels are made long and slender. Another example is capacitive decoupling, where an extra hole is placed within a nozzle plate to damp pressure surges by allowing the meniscus within this dummy nozzle to oscillate rather than the meniscus at an ejection nozzle. Others use elaborate constrictions and expansions within the fluid chamber to help achieve this goal. Given the high nozzle density and the high frequency of operation requirements of current liquid ejectors, all the above-mentioned solutions are marginal at best.  
         [0065]     The present invention provides a solution that allows high packing density while significantly decoupling adjacent nozzles. The extension of the chamber walls  130  of the liquid chambers  20  slightly into the liquid supply passageway  70  along with the removal of the problematic prior art common area  50  ( FIG. 1A ) that was discussed in  FIG. 2 . It needs to be understood at this point that filtering through the prior art common area  50  ( FIG. 1A ), using a variety of shaped filter elements as is practiced in the art, is extremely detrimental for crosstalk because it maintains a commonality of high-pressure regions between adjacent nozzles. The elimination of the prior art common area  50  ( FIG. 1A ), and the extension of the chamber walls  130  of the liquid chambers  20  slightly into the liquid supply passageway  70 , brings success in drastically eliminating crosstalk. This occurs because we direct the impulsive motion of the liquid  40  to face the inherently much larger low-pressure area of the liquid supply passageway  70  rather than the inherently higher-pressure area of the prior art common area  50  ( FIG. 1A ) as discussed in  FIG. 2 . This fact causes the liquid  40  to have a significantly harder time to push its way into an adjacent liquid chamber  20  with its higher chamber pressure.  
         [0066]      FIG. 10  details a cross-sectional view of a liquid drop ejector  10  previously detailed in  FIG. 9 , and shows the extension of the chamber walls  130  into and over the liquid supply passageway  70 . Note again that the elimination of the prior art common area  50  ( FIG. 1A ), and the extension of the chamber walls  130  of the liquid chambers  20  slightly into the liquid supply passageway  70 , brings success in eliminating crosstalk for the reasons described in the previous paragraph.  
         [0067]     Referring to  FIG. 11 , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  of the present invention. A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the whole length of the liquid drop ejector  10 .  
         [0068]     Liquid  40  is supplied via a liquid supply passageway  70  and is ultimately ejected through nozzle  80 . A chamber wall  130  exists as a separation between adjacent liquid chambers  20 . The length of the chamber wall  130  has been found to have a positive effect on crosstalk between adjacent liquid chambers  20 . The extension of this chamber wall  130  into and over the liquid supply passageway  70  minimizes cross-communication between adjacent liquid chambers  20  (also known as crosstalk). In addition to this reduction of crosstalk, it is also advantageous to add the capability of filtering. It is commonplace for practitioners of the art to use pillars  90  for the purpose of filtering and support. These pillars  90  exist in a prior art common area  50  that exists between the liquid chamber  20  and the liquid supply passageway  70 . The placement of pillars  90  within the liquid supply passageway  70 , instead of the prior art common area  50  ( FIG. 1A ), produces significantly enhanced refill, while still preserving effective filtering. The suspension of pillars  90  directly within the liquid supply passageway  70 , as opposed to the prior art placement of these pillars  90  within a prior art common area  50  ( FIG. 1A ), allows for a shorter distance that the liquid  40  is required to flow to refill the liquid chamber  20 . Thus, the refilling time of the liquid chamber  20  of the liquid drop ejector  10  is substantially improved, along with the aforementioned reduction of crosstalk.  
         [0069]      FIG. 12  details a cross-sectional view of the liquid drop ejector  10  previously detailed in  FIG. 11 , and shows the extension of the chamber walls  130  into and over the liquid supply passageway  70 . Note again that the elimination of the prior art common area  50  ( FIG. 1A ) and the extension of the chamber walls  130  of the liquid chambers  20  slightly into the liquid supply passageway  70  bring success in drastically eliminating crosstalk. Additionally, the placement of pillars  90  within the liquid supply passageway  70 , instead of the prior art common area  50  ( FIG. 1A ) produces significantly enhanced refill, while still preserving effective filtering.  
         [0070]     Referring now to  FIG. 13 , detailed is a cross-sectional view of a liquid drop ejector  10  of the present invention. The liquid supply passageway  70  is containment for fluid  40 . This being understood, the fluid supply passageway  70  has walls that are both perpendicular and parallel to the nozzle bore  80 . Referring again to  FIG. 13 , pillars  90  are shown residing upon a first perpendicular wall of the fluid supply passageway  70 . Next referring to  FIG. 14  pillars  90  are shown residing upon a second perpendicular wall of the fluid supply passageway  70 .  FIG. 12  details pillars  90  that reside upon a wall that is substantially parallel to the nozzle  80 .  
         [0071]     Referring next to  FIG. 15 , detailed is a cross-sectional view of a liquid drop ejector  10  of the present invention. In this diagram, a separate nozzle plate  100  is attached along the dashed line to form a roof for the liquid drop ejector  10 . Nozzle plate  100  also contains both the liquid chamber  20  and the liquid supply passageway  70 . Pillars  90  are shown suspended from the nozzle plate  100 . It should be understood at this time that pillars  90  can be suspended in the liquid supply passageway  70  both upon a wall  25  that is perpendicular to the nozzle bore  80  and upon a wall  35  that is parallel to the nozzle bore  80 .  
         [0072]     Referring back to  FIG. 13  and  FIG. 12  respectively, detailed is a side view of the liquid drop ejector  10  of the present invention.  FIG. 13  details pillars  90  are suspended in the liquid supply passageway  70  in a plane that is perpendicular to the nozzle bore  80  of liquid chamber  20 .  FIG. 12  details that pillars  90  are suspended in the liquid supply passageway  70  in a plane that is parallel to the nozzle bore  80  of liquid chamber  20   
         [0073]     Referring to  FIG. 16 , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  of the present invention. A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the entire length of the liquid drop ejector  10 . Liquid  40  is supplied via a liquid supply passageway  70 , and flows past pillars  90  that are used to trap particles that could plug liquid chamber  20  and/or nozzle bore  80  thus rendering a portion of the liquid drop ejector useless. It is commonplace for practitioners of the art to use pillars  90  for the purpose of filtering and support. The placement of pillars  90  within the liquid supply passageway  70  produces significantly enhanced refill, while still preserving effective filtering. This suspension of pillars  90  directly within the liquid supply passageway  70  allows for a shorter distance that the liquid  40  is required to flow to refill the liquid chamber  20 . Thus, the refilling time of the liquid chamber  20  of the liquid drop ejector  10  is substantially improved. Referring also to  FIG. 16 , there exists a center pillar  90   a  wherein a first portion of the center pillar  90   a  is positioned within the liquid chamber  20  and wherein a second portion of the center pillar  90   a  is positioned within the liquid supply passageway  70 .  
         [0074]      FIG. 17  details a cross-sectional view of a liquid drop ejector  10  previously detailed in  FIG. 16 , and shows the suspension of the pillars  90  directly within the liquid supply passageway  70 . Note again that the suspension of the pillars  90  within the liquid supply passageway  70  allows a shorter liquid chamber  20 . Referring also to  FIG. 16 , there exists a center pillar  90   a  wherein a first portion of the center pillar  90   a  is positioned within the liquid chamber and wherein a second portion of the center pillar  90   a  is positioned within the liquid supply passageway  70 .  
         [0075]     Referring to  FIG. 18 , detailed is a center pillar  90   b  positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . Pillar  90   b  has a top and a bottom (two ends). The top end of the pillar  90   b  is attached to a first wall (or roof  110 ) of the liquid supply passageway  70 , and the bottom end is attached to a second wall (or floor  120 ) of the liquid supply passageway  70 . A first portion of the second end (bottom) of pillar  90   b  is positioned within the liquid chamber  20 , and a second portion of the second end (bottom) of pillar  90   b  is positioned within the liquid supply passageway  70 .  
         [0076]     Referring to  FIG. 19 , detailed is a greatly magnified partial planar view of a liquid drop ejector  10  of the present invention. A liquid chamber  20  exists to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the entire length of the liquid drop ejector  10 . Liquid  40  is supplied via a liquid supply passageway  70 , and flows past center pillars  90   a  that are used to trap particles that could plug liquid chamber  20  and/or nozzle bore  80  thus rendering a portion of the liquid drop ejector useless. Referring also to  FIG. 19 , note that center pillars  90   a  have a first portion positioned within the liquid chamber  20  and a second portion positioned within the liquid supply passageway  70 .  
         [0077]      FIG. 20  details a cross-sectional view of a liquid drop ejector  10  previously detailed in  FIG. 19 , and shows the suspension of the pillars  90   a  partially within the liquid supply passageway  70 . Note again, that the pillars  90   a  have a first portion positioned within the liquid chamber  20  and a second portion positioned within the liquid supply passageway  70 .  
         [0078]     Referring now to  FIG. 21 , detailed are pillars  90   b  positioned with a first portion positioned within the liquid chamber  20  and a second portion positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . Pillars  90   b  have a top and a bottom (two ends). The top end of the pillars  90   b  is attached to a first wall (or roof  110 ) of the liquid supply passageway  70 , and the bottom end is attached to a second wall (or floor  120 ) of the liquid supply passageway  70 . A first portion of the second end (bottom) of pillars  90   b  is positioned within the liquid chamber  20 , and a second portion of the second end (bottom) of pillars  90   b  is positioned within the liquid supply passageway  70 .  
         [0079]     Referring to  FIG. 22 , detailed is the addition of suspended pillars  90  that are positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . Note that one end of the pillars  90   b  is attached the wall (or roof  110 ) of the liquid supply passageway  70 , and the second or bottom end is hanging freely into the liquid supply passageway  70 . The placement of pillars  90  within the liquid supply passageway  70  produces significantly enhanced refill, while still preserving effective filtering.  
         [0080]     Referring to  FIG. 23 , detailed is the addition of alternate pillars  90  that are positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . One end of the pillar  90   b  is attached to a first vertical wall of the liquid supply passageway  70 , and the second or bottom end is hanging freely into the liquid supply passageway  70 . The placement of pillars  90  within the liquid supply passageway  70  produces significantly enhanced refill, while still preserving effective filtering.  
         [0081]     Referring to  FIG. 24 , detailed is the addition of yet another alternate pillars  90  that are positioned within the liquid supply passageway  70  of the liquid drop ejector  10 . One end of the pillar  90   b  is attached to a second vertical wall of the liquid supply passageway  70 , and the second or bottom end is hanging freely into the liquid supply passageway  70 . The placement of pillars  90  within the liquid supply passageway  70  produces significantly enhanced refill, while still preserving effective filtering.  
         [0082]     It should be noted that  FIG. 2  and  FIG. 3  are both side views of the liquid drop ejector  10  of the present invention. Referring to the area of the liquid supply passageway  70 , there exists a plurality of walls.  FIG. 2  details a wall perpendicular to the nozzle bore  25  upon which pillars  90  are attached.  FIG. 3  details a wall parallel to the nozzle bore to which pillars  90  are attached.  
         [0083]     Referring now to  FIG. 25  detailed is a side view of the liquid drop ejector  10  of the present invention. Referring to the area of the liquid supply passageway  70 , there exists a plurality of walls. In this configuration a nozzle plate  100  covers the liquid chambers  20 .  FIG. 25  details a nozzle plate  100  that extends between the liquid chambers  20  and the liquid supply passageways  70 , to which pillars  90  and center pillars  90   b  are attached.  
         [0084]     Referring back to  FIG. 23  and  FIG. 22  respectively, detailed is a side view of the liquid drop ejector  10  of the present invention.  FIG. 23  details pillars  90  are suspended in the liquid supply passageway  70  in a plane that is perpendicular to the nozzle bore  80  as viewed from a plane perpendicular to a cross sectional view of the nozzle bore  80 .  FIG. 22  details that pillars  90  are suspended in the liquid supply passageway  70  in a plane that is parallel to the nozzle bore  80  as viewed from a plane perpendicular to a cross sectional view of the nozzle bore  80 .  
         [0085]     Referring next to  FIG. 26 , detailed is a side view of the liquid drop ejector  10  of the present invention, wherein the liquid chambers  20  exist to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the entire length of the liquid drop ejector  10 . This defines liquid supply passageways  70 , one existing on each side of block  30 , and where there is associated with the liquid drop ejector  10 . A drop forming mechanism  140  exists within the liquid chamber  20 .  
         [0086]     Referring now to  FIG. 27  and  FIG. 28  detailed is a side view of the liquid drop ejector  10  of the present invention. Liquid chambers  20  exist to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the entire length of the liquid drop ejector  10 .  FIG. 27  details an embodiment wherein there exists a heater below  150  the nozzle bore  80  of the liquid chamber  20 .  FIG. 28  details an embodiment wherein there exists a heater adjacent  160  the nozzle bore  80  positioned within the liquid chamber  20 .  
         [0087]     Referring lastly to  FIG. 29 , detailed is a side view of the liquid drop ejector  10  of the present invention. Liquid chambers  20  exist to forcibly eject a liquid  40  from liquid chamber  20  through nozzle bore  80  for a wide variety of purposes such as image reproduction. Note that by virtue of block  30  there exists a pair of well-defined liquid supply passageways  70 . These liquid supply passageways  70  run along the entire length of the liquid drop ejector  10 . It should be understood that the pillars  90  that exist within the liquid drop ejector  10  could embody a variety of shapes and configurations including shapes that are circular and shapes that the perimeter of its cross section forms a variety of closed curves.  
         [0088]     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.  
       PARTS LIST  
       [0000]    
       
           10  liquid drop ejector  
           20  liquid chamber  
           21  center block  
           25  wall perpendicular to nozzle bore  
           30  block  
           35  wall parallel to nozzle bore  
           40  liquid  
           50  common area  
           60  liquid supply  
           70  liquid supply passageway  
           80  nozzle bore  
           90  pillar  
           100  nozzle plate  
           110  roof  
           120  floor  
           130  chamber wall  
           140  drop forming mechanism  
           150  heater below  
           160  heater adjacent