Abstract:
A printing system includes a high volumetric efficient free-ink container vessel. The vessel includes a reservoir to store a supply of ink. A vent hole in the reservoir links atmospheric air to the reservoir. A mechanical vent system selectively opens and closes the vent hole in the reservoir. The mechanical vent system is equipped with a movable member that moves between a closed position covering the vent hole and an open position uncovering the vent hole. The mechanical vent system moves the movable member to open and close the vent hole. When the vent hole is open, non-atmospheric pressures imparted within the reservoir can be virtually eliminated by the exemplary mechanical vent system.

Description:
BACKGROUND  
         [0001]    The present invention relates to printing systems, and more particularly, to printing systems that make use of ink container vessels for delivery of ink to printing delivery systems.  
           [0002]    Printing systems, such as ink-jet printing systems, typically use ink container vessels. Most ink container vessels used in popular printing systems today deploy some type of sold material within their reservoirs such as porous material or collapsible film. The porous material and/or collapsible films are used in the vessel containers to provide a means of preventing ink from leaking out of vents in the containers and to provide backpressure for the ink delivery system. These solid parts also prevent spillage of ink through vent holes of the container vessels during shipment and handling of them.  
           [0003]    Such ink container vessels are typically purchased pre-filled with ink and are discarded after they run out of available ink. A serious drawback of such vessels, however, is that they often strand between 15% and 50% of their initial total fill of ink after depleting available ink for the printing system. “Strand” means that ink remains in the container vessels when they are discarded, because the ink cannot be accessed by the printing system. In other words, most current ink container vessels permanently leave behind up to half their initial volume of total ink in the vessel when the container needs to be discarded. Ink becomes trapped and lodged in nooks of the container to become permanently stranded and/or becomes trapped in porous materials used inside a vessel to retain the ink.  
           [0004]    Moreover, volumetric efficiency of an ink supply container vessel suffers because of the presence of solid materials throughout the reservoir of a vessel. Such solid parts fill volume that may otherwise be used to store ink. Additionally, printer manufacturers often construct ink container vessels with larger volumetric ink capacities in order to compensate for the stranding of large percentages of ink. Unfortunately, larger vessels also increase the total size of printer products, because printer systems must be able to accommodate these larger vessels. Larger vessels also require higher initial fill volumes of ink, which is costly.  
           [0005]    Furthermore, many current ink container vessels are also environmentally unfriendly; because they often cannot be easily recycled due to the amount of stranded ink left in the vessels once they have to be discarded (i.e., once there is no available ink for printing).  
           [0006]    Still another problem associated with many current ink container vessels is the fluctuation of pressures within the container&#39;s reservoir. It is common for ink container vessels to be exposed to temperature and altitude variations, which causes air volume within the reservoir to expand or contract. Such pressure variations have a negative impact on ink delivery systems, because it skews the consistency of ink flow delivered to printing media. Air expansion in a closed ink container may cause ink to be pushed out of the ink delivery system forcing ink to leak out of the system. Vessels that use solid materials in the reservoir impart flow restrictions on ink (in addition to trapping ink as described above), which also affects the quality of ink delivery systems and limits the types of ink delivery systems that can be used in combination with such vessels.  
         SUMMARY OF THE INVENTION  
         [0007]    Exemplary embodiments of the present invention comprise high volumetric efficient free-ink container vessels. The vessels include a reservoir to store a supply of ink. A vent hole in the reservoir links atmospheric air to the reservoir. A mechanical vent system selectively opens and closes the vent hole in the reservoir. The mechanical vent system is equipped with a movable member that moves between a closed position covering the vent hole and an open position uncovering the vent hole. The mechanical vent system moves the movable member to open and close the vent hole. When the vent hole is open, non-atmospheric pressures imparted within the reservoir can be virtually eliminated by the exemplary mechanical vent system.  
           [0008]    The exemplary high volumetric efficiency ink container described herein, therefore, introduces the broad concept of employing a mechanical vent system that imposes no pressure effects on the ink delivery system. The vent system is able to open the supply of air to the interior of the vessel when the vessel is inserted into the printer and close the supply of air when removed from the printer. Additionally, the vent system is able to open/close the vent hole at prescribed times. The exemplary high volumetric efficiency ink container of the present invention also allows positioning of the fluid interconnect port at substantially the lowest point of fluid reservoir, resulting in only a small residual portion of ink being stranded in ink container vessels when the ink supply is depleted. Furthermore, the vessel may be used with a wide variety of ink delivery systems, since there are no pressurized effects caused by the vessel. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears.  
         [0010]    [0010]FIG. 1 is a simplified block diagram of an exemplary ink-jet printing system that can be utilized to implement.  
         [0011]    [0011]FIG. 2 is an enlarged, cross-sectional view of an exemplary ink container vessel with a vent hole in a closed position.  
         [0012]    [0012]FIG. 3 is another cross sectional view of an exemplary ink container vessel with the vent hole in an open position.  
         [0013]    [0013]FIG. 4 is an external partial view of the exemplary vessel shown in FIGS. 2 and 3.  
         [0014]    [0014]FIG. 5 is identical to FIG. 4, but shows the addition of an exemplary face plate attached to an exterior wall of vessel.  
         [0015]    [0015]FIG. 6 is identical to FIGS. 2 and 3, but shows the addition of a labyrinth sealing member as well as other elements associated with sealing the vent hole from the exterior of the vessel when a rod is inserted in the vent hole. 
     
    
     DETAILED DESCRIPTION  
       [0016]    [0016]FIG. 1 is a simplified block diagram of an exemplary ink-jet printing system  100 . As used herein, “printing system” means any electronic device having data communications, data storage capabilities, and/or functions to render printed characters and images on a print media. A printing system may be a printer, fax machine, copier, plotter, and the like. The term “printing system” includes any type of printing device using a transferred imaging medium, such as ejected ink, to create an image on a print media. Examples of such a printer can include, but are not limited to, inkjet printers, plotters, portable printing devices, as well as multi-function combination devices. Although specific examples may refer to one or more of these printers, such examples are not meant to limit the scope of the claims or the description, but are meant to provide a specific understanding of the described implementations.  
         [0017]    Printing system  100  includes one or more of the following: a processor  102 , an ink container vessel  104 , an ink delivery system  106  and memory  108 . Additionally, although not shown, a system bus as well as mechanical connections, such as fluid interconnects, typically connects the various components within printing system  100 .  
         [0018]    Processor  102  processes various instructions to control the operation of system  100  and to communicate with other electronic and computing devices. Essentially processor  102  manages the overall operation of printing system  100 . Memory  108  is used to store instructions and messages useful for processor  102  to manage operation of system  100 , including communicating with other devices. Memory  108  may include programmable and/or permanent storage of data and instructions. Various types of memory devices, depending on the complexity of system  100 , may be deployed.  
         [0019]    Ink container vessel  104  stores a supply of ink for the printing system  100 . As used herein, vessel  104  may also be referred to as an ink container vessel or a printer cartridge. Vessel  104  shall be described in more detail below, with reference to FIGS.  2 - 6 . Ink delivery system  106  is typically connected to ink container vessel  104  by flexible tubing conduit or hollow needle (tubing and needle not shown but well understood by those skilled in the art). System  106  selectively extracts ink stored in vessel  104  and deposits the ink on media (not shown). Ink delivery system  106  can include an inkjet printing mechanism that selectively causes ink to be applied to a print media in a controlled fashion. It should be noted, however, that the exemplary ink delivery system  106  used with the ink container vessel of the present invention is a Spring-bag regulator system. However, there are many different types of ink delivery systems  106  available, such as Foam or other capillary material. For discussion purposes ink delivery system  106  can include any of these different types of systems.  
         [0020]    [0020]FIG. 2 shows a cross sectional view of an exemplary ink container vessel  104 . Ink container vessel  104  includes: a chassis  202 , a reservoir  204 , a vent hole  206 , a septum  208 , and a mechanical vent system  210 . Ink container vessel  104  may be designed to be releasably installed in a receiving slot (not shown) of printing system  100 . It should be noted that FIG. 2 is enlarged to better aid in illustrating the vessel  104  and is not necessarily drawn to scale.  
         [0021]    Chassis  202  is composed of a non-collapsible rigid (or semi-rigid) material and may be formed of many different shapes not limited to FIG. 2, depending on the application. For purposes of this exemplary illustration, chassis  202  is composed of rigid plastic that can either be injection molded or blow molded to enable various configurations.  
         [0022]    Reservoir  204  is designed to store a supply of ink for delivery system  106 . Reservoir  204  is internal to chassis  202  and may initially store a supply of ink up to the maximum volumetric size of reservoir  204 .  
         [0023]    Septum  208  serves as a fluid outlet for ink stored in reservoir  204 . That is, ink stored in reservoir  204  is fluidly connected to septum  208 . Septum  208  prevents ink from extruding from chassis  202 , i.e., it acts as a sealing mechanism, when ink container  104  is out of the printer. On the other hand, when ink container  104  is installed in the printer, septum  208  allows fluidic connection between ink in reservoir  204  and ink delivery system  106 ; usually via tubing (not shown) or other fluid interconnections, such as a hollow needle (shown in FIG. 3 as  304 ). It should be noted that once vessel  104  is inserted in a printing system  100  and vent hole  206  is opened, as described below, no pressure excursion effects are incurred within reservoir  204  or vessel  104 . One feature of the exemplary printing system  100  is an ink container vessel  204  that employs a vent system that imparts little-to-no flow restrictions on ink delivery systems.  
         [0024]    Vent hole  206  is a cylindrically shaped opening through a wall  218  of chassis  202 . As will be explained in more detail below, vent hole  206 , when open, permits a free flow of air in and out of reservoir  204  through a labyrinth (shown in FIGS. 4 and 5). Typically, vent hole  206  is located on the upper portion of an ink container vessel  104  above the ink level in reservoir  204 , but may be incorporated into any other location on vessel  104  that permits adequate air supply. The quantity of vent holes  206 , their size and shape may vary, depending on the printing system, size of vessel  104  and application needs.  
         [0025]    Mechanical vent system  210  as shown in FIG. 2 includes a sealing member  212  and compression spring  214 . Sealing member  212  is a flat disk having the same cylindrical shape as vent  206 , except with a larger diameter to ensure that sealing member  212  extends over vent hole  206  when sealing member  212  comes in contact with vent hole  206 . Sealing member  212  could also be other shapes depending on the shape of the vent hole  206 . Additionally, instead of fitting over vent hole  206 , sealing member  212  could fit-in vent hole  206  to act as a plug. For instance, sealing member  212 , may have a cork shape and form a seal in vent hole  206  when inserted therein.  
         [0026]    Sealing member  212  resides in a chamber  220 , which is simply an area within chassis  202  that sealing member  212  is able to move, which in this exemplary illustration is in a horizontal direction without interference. Sealing member  212  has an exterior side  222  and interior side  224 . When sealing member  212  is seated against vent hole  206  (i.e., vent hole  206  is closed), exterior side  222  of sealing member  212  is in gas communication with the atmosphere through a labyrinth (to be described) and interior side  224  of sealing member  212  is either in fluid and/or gas communication with ink in reservoir  204 . The exemplary sealing member  212  is constructed from a common rubber, but other elastomer or non-elastomer materials may be substituted for rubber as would be appreciated by those skilled in the relevant art.  
         [0027]    Compression spring  214  is coupled between the interior side  224  of sealing member  212  and a housing seat  216  in chassis  202 . Housing seat  216  provides a back surface for spring  214  to compress against. Compression spring  214  is disposed to resiliently press against the interior side  224  of sealing member  212 . When compression spring  214  is expanded, it forces the exterior side  222  of sealing member  212  to abut against (e.g., come into contact with) vent hole  206 , thereby closing vent hole  206 . Although the exemplary implementation shows a compression spring  214 , other compression members may be used in place of a compression spring such as an elastomer integrated with sealing member  212  and other related devices.  
         [0028]    As shown in FIG. 2, overlapping edges  226 A and  226 B of sealing member  206  come into contact with the interior side of chassis  202  around vent hole  206 . Accordingly, vent hole  206  is closed and sealed by the force of compression spring  214  resiliently pressing sealing member  212  with its overlapping edges  226  against the interior side of chassis  202  and sealing member&#39;s  212  coverage of vent hole  206 .  
         [0029]    It is desirable, in certain circumstances, for vent hole  206  to be closed when printing system  100  and/or ink delivery system  106  is not active. For instance, during transportation of vessel  104  itself, it is preferable that vent hole  206  is closed to prevent the ink supply in reservoir  204  from evaporating or leaking out vent hole  206 . Additionally, once vessel  104  is installed into printing system  100 , it may take many months to fully deplete reservoir  204  of its supply of ink. Mechanical vent system  210  through the use of compression spring  214  and sealing member  212 , ensure that vent hole  206  automatically remains closed (e.g., sealing member  212  seals hole  206  from the expansion force of spring  214 ), when print system  100  and/or ink delivery system  106  is inactive, or vessel  104  is transported. The closure of vent hole  206  during printer inactivity or vessel transportation prevents ink from evaporating from reservoir  204  via hole  206  or leaking out during environmental fluxuations. Opening of vent hole  206  by mechanical vent system  210  shall now be described.  
         [0030]    [0030]FIG. 3 shows another cross-sectional view of an exemplary ink container vessel  104 , with vent hole  206  opened (i.e., sealing member  212  has shifted away from vent hole  206  releasing its seal). In this exemplary Figure, mechanical vent system  210  further includes a rod (also referred to as printer pin)  302 , which is shown inserted and extending through the cylindrical housing of vent  206  and chamber  220 . The right end  304  of rod  302  applies a load against the exterior side  222  of sealing member  212  with a greater force than exerted by compression spring  214 , forcing spring  214  to compress against the inside of chassis  202  around base  216 . Accordingly, sealing member  212  moves away (i.e. shifts away) from vent hole  206 , thereby opening vent hole  206 .  
         [0031]    The opening of vent hole  206  can occur at different times by different means. For example, the other end  306  of rod  302  may be in a fixed position attached (attachment not shown) to printing system  100 . Accordingly, a user activates the opening of vent hole  206 , by lining-up vent hole  206  with rod  302 . Then a user pushes the vessel  104  against the rod  302  while simultaneously seating the vessel  104  into its receiving slot (not shown) within a printing system  100 . A fixed pin enables automatic opening of vent hole  206 , when the vessel is seated in a printing system  100  and automatic closing of vent hole  206  when the vessel is removed from printing system  100 .  
         [0032]    On the other hand, rod  302  may engage sealing member  212  after vessel is installed in the printer system  100  by a mechanical actuator (not shown). In this implementation, rod  302  moves in an exemplary horizontal direction to engage and push back sealing member  212 . Such a dynamic rod  302  could open and close vent hole  206 , when printing system  100  is active or inactive, respectively. A moveable rod  302  may be implemented as a piston. A dynamically moveable rod  302 , however, would be more costly than a stationary rod of the previous implementation, because it would require additional mechanisms such as a hydraulic system. Nevertheless, for reduced costs and simplified printing system  100 , a fixed stationary pin  302  is preferred.  
         [0033]    Rod  302  is a composed of Stainless Steel, but other material including plastics could be employed. Also shown in FIG. 3, is a hollow needle  304  inserted in septum  208  to represent that vessel  104  has been inserted into printing system  100 .  
         [0034]    [0034]FIG. 4 is an external partial view of the exemplary vessel  104  shown in FIGS. 2 and 3. In this exemplary illustration, a labyrinth  402  includes a channel  404  that is molded directly into an external surface of wall  406 . The exemplary channel  404  employs a laborious tortuous path linking vent hole  206  to an air flow receptacle  408 . Receptacle  408  serves as a chief port for air to enter the tortuous path of channel  404 , as shall become more apparent from the description below. Of course other shaped tortuous paths and channels may be employed including cylindrical paths as is well known in the art. As shown in FIG. 4, rod  302  is inserted through vent hole  206 . The operation and further description of labyrinth  404  in conjunction with mechanical venting system  210  shall be described with reference to FIGS. 5 and 6 below.  
         [0035]    [0035]FIG. 5 is identical to FIG. 4, but shows the addition of an exemplary face plate  502  attached to wall  406  with a large portion of labyrinth  402  covered by face plate  502 . A portion of channel  404  is left uncovered, which in this Figure is air receptacle  408 . This permits air to travel from receptacle  408  to vent  206 . Face plate  502  is made of Polypropylene film and can be attached to wall  406  by an adhesive bonding material such as pressure sensitive adhesive. Face plate  502  may be composed of other barrier materials such as reinforced aluminum foil.  
         [0036]    To further ensure that the only path to vent hole  206  is through air receptacle  408 , a seal may also be placed around vent hole  206  and rod  302 , when vent  206  is open. To better illustrate one such exemplary seal, reference is made to FIG. 6, which is identical to FIGS. 2 and 3, but shows the addition of a labyrinth sealing member  602  and other exemplary elements. Any gaps between rod  302  and face plate  502  through vent hole  206  is completely covered and sealed by a labyrinth seal  602 . A labyrinth compression spring  606  provides a load against labyrinth seal  602  forcing the seal  602  against wall  406 . Two identical plates  604 A,  604 B provide a means for labyrinth compression spring  606  to press firmly against labyrinth seal  602 . Plates  604  distribute the force of labyrinth compression spring  606  to labyrinth seal  602 . Labyrinth compression spring  606  is attached to a printer chassis (not shown) on the opposite end of rod  302 . The printer chassis provides a back surface for the labyrinth compression spring  606  to compress against.  
         [0037]    Additionally, labyrinth seal  602  is fixed around the circumference of rod  302  in a hermetic fashion. The exemplary labyrinth seal  602  is disk shaped with added thickness around the rod  302 . Accordingly, when labyrinth seal  602  is in place, the only air communication with vent  206  is through air receptacle  408  shown in FIGS. 4 and 5. Labyrinth seal  206  is preferably made of a common rubber material, but other elastomer or non-elastomer materials may be substituted for rubber as would be appreciated by those skilled in the relevant art. The size, thickness and shape may of labyrinth seal vary, depending on the size of rod  302 , vent hole  206  and labyrinth  402 . All such considerations, however, are well within the purview of a person skilled in the relevant art.  
         [0038]    When vessel  104  is inserted in a printing system  100  and vent hole  206  is open as shown in FIG. 6, air flow communication is actuated between reservoir  204  and the atmosphere, via labyrinth  402 . Additionally, labyrinth  402  aids in preventing ink evaporation once vent  206  is opened by mechanical vent system  210 .  
         [0039]    Another feature of the exemplary printing system  100  described above is an exemplary ink container vessel  104 , in which environmental pressures imparted within the reservoir of the vessel, can be virtually eliminated by the exemplary mechanical vent system  210  in conjunction with vent hole  206 .  
         [0040]    Still another feature of the exemplary printing system  100  is the ability to employ “free-ink” (that is, without the use of porous, absorbent, or solid materials in the reservoir  204 , such as foam mentioned in the Background Section above) container vessels  104 , which enables the highest volumetric efficiency for ink storage, while simultaneously providing for a greater variety of container shapes than non-“free-ink” vessels. Free-ink vessels  104  are also friendlier to the environment than conventional ink vessels, which are not recyclable and often leak ink into the environment once discarded.  
         [0041]    Yet another feature of the exemplary printing system  100  is a tremendous reduction of stranded ink. Ink containers employing the inventive concepts described above typically strand less than three percent of the total initial fill volume of the ink container, which is between 5-to-16 times better than current porous media and film containers. The placement of the fluid port at substantially the lowest point of the fluid reservoir further serves to reduce stranded ink. A free ink container fills the available space, thus having nearly 100% volumetric efficiency and it can have very low stranded ink, therefore providing the end user with the maximum value in printing consumables. Another significant advantage of the present invention is that during ink fill there need be no concern of leaving air in the container and therefore the ink fill can occur through one or both of the interconnects. This allows for a much faster ink fill, which is a significant manufacturing advantage.  
         [0042]    A further feature of the present invention is the placement of the fluid interconnect port and the vent port on the same face of the container, with both both interconnections occurring during the installation of the ink container into the printer. This arrangement enables manufacturing technology such as blow molding, which is very low cost and very flexible in the shapes that can be generated.  
         [0043]    Thus, although some preferred implementations of the various methods and arrangements of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the exemplary aspects disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.