Abstract:
A printing system includes a high volumetric efficient free-ink container vessel. The vessel includes an autonomous venting system, which supplies air to, and/or seals, the interior of the ink container in concert with an ink delivery system without reliance on external mechanical devices, feedback or control systems. The autonomous vent system includes a flexible diaphragm with a hole. The autonomous vent system is configured to autonomously open the diaphragm hole to permit atmospheric air to enter the vessel when ink is extracted from the vessel by the ink delivery system, and autonomously close the diaphragm hole when the ink delivery system is inactive. Closing and opening of the hole is actuated by pressure differentials between the interior of the ink container and atmospheric ambient pressure.

Description:
BACKGROUND 
     1. Field of the Invention 
     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. 
     2. Related Art 
     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 solid 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. For instance, it is common for reservoir pressure to build-up in vessels due to upsurges in temperature or changes in altitude which can result in ink leakage. These solid parts also prevent spillage of ink through vent holes of the container vessels during shipment and handling of them. 
     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 and 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. 
     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. 
     Furthermore, current ink container vessels are also environmentally unfriendly; because they often cannot be 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). 
     To date, attempts to create ink container vessels that do not strand ink and are volumetric efficient are too costly or are ill-suited with the conveniences of current print system designs. 
     SUMMARY 
     The present invention is directed to a printing system that includes a high volumetric, free-ink container vessel for supplying ink to the printing system. In one embodiment, the ink container vessel includes a vent hole and an autonomous vent system. An ink delivery system is coupled to the vessel for the purpose of extracting ink stored in the vessel for the printing system. The autonomous vent system uses a flexible diaphragm to cover the vent hole. The autonomous vent system also has a diaphragm hole that is smaller than the vent hole. The autonomous vent system is configured to autonomously open the diaphragm hole to permit atmospheric air to enter the vessel when ink is extracted from the vessel by the delivery system, and autonomously close the diaphragm hole when the delivery system is inactive. 
     The exemplary printing system, therefore, introduces the broad concept of employing an autonomous vent supply for an ink container vessel. The vent is able to control the supply of air to the interior of the vessel in concert with the ink delivery system, without manipulation of other devices and control systems. As a result of innovative concepts herein, only a residual portion of ink is stranded in ink container vessels after the available ink supply is fully depleted. 
     In another implementation, the exemplary description is directed to an ink container that has a vent hole located through the exterior shell of the container. The container also contains an autonomous vent system, which comprises a flexible diaphragm fitted over the vent hole. The diaphragm has a diaphragm hole that is smaller than the vent hole. The diaphragm hole is also positioned over the vent hole. Accordingly, an interior side of the flexible diaphragm faces the interior side of the container and the exterior side of the flexible diaphragm faces atmospheric air. A sealing member is configured to press against the exterior side of the diaphragm and seal the diaphragm hole when the pressure in the container, (which is exerted against the interior side of the diaphragm) is greater than atmospheric pressure exerted against the exterior side of the diaphragm. On the other hand, when atmospheric air pressure exerted against the exterior side of the diaphragm exceeds the pressure inside the vessel, the flexible diaphragm is configured to flex away from sealing member and toward the interior side of the vessel. 
     One feature of the exemplary printing system is that the autonomous venting system does not add cost or complexity to a printer system, because the vent system relies on pressure differences between the reservoir of the ink container and the atmosphere exerted against the diaphragm, to control the flow of air to the ink container and/or seal the reservoir of a vessel from ink excursions or drying external air flow. 
     Another feature of the exemplary printing system is the ability to employ “free-ink” (that is, without the use of porous, absorbent, or solid materials in the reservoir, such as foam mentioned in the Background Section above) container vessels, 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 are also friendlier to the environment than conventional ink vessels, which are not recyclable and often leak ink into the environment once discarded. 
     Still another feature of the exemplary printing system is a tremendous reduction of stranded ink. Ink containers employing the inventive concepts described herein 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. 
     Further features and advantages, as well as the structure and operation of various embodiments are described in detail below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
         FIG. 1  is a simplified block diagram of an exemplary ink-jet printing system  100  that can be utilized to implement the inventive techniques of the present invention. 
         FIG. 2  is a view of an exemplary ink container vessel. 
         FIG. 3  is a cross sectional view of an exemplary autonomous venting system. 
         FIG. 4  is a more detailed cross sectional view of the exemplary autonomous venting system illustrated in FIG.  3 . 
         FIG. 5  illustrates a topical view of an exemplary autonomous venting system shown from the exterior of an ink containment vessel. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a simplified block diagram of an exemplary ink-jet printing system  100  that can be utilized to implement the inventive techniques of the present invention. 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. System  100  will now be described in more detail. 
     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 . Furthermore, although well appreciated by those skilled in the relevant art, additional components of standard commercial printing systems are not described herein, as they are superfluous to understanding and describing the exemplary embodiments of the present invention. 
     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 . Whereas 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 as is appreciated by those skilled in the art. 
     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 a printer cartridge. Vessel  104  shall be described in more detail below, with reference to  FIGS. 2 and 3 . 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 is a Spring-bag pressure regulator system. Those skilled in the art will recognize, however, that there are many different types of ink delivery systems  106  available such as foam or other capillary material and that for the purposes of this description, ink delivery system  106  can include any of these different types of systems. 
     Referring to  FIG. 2  is a view of an ink container vessel  104  according to an exemplary embodiment of the present invention. Ink container vessel  104  includes: a chassis  202 , a reservoir  204 , an autonomous vent system  206  and a septum  208 . 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 inventive features of the embodiment and is not necessarily drawn to scale. 
     Chassis  202  is preferably 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. 
     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 . 
     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 (also not shown). Those killed in the art understand and appreciate the mechanics of septums. 
     Autonomous venting system  206  autonomously permits the supply of air to flow into reservoir  204 , typically, when ink is extracted from ink reservoir  204  via septum  208 . Autonomous venting system  206  also autonomously seals ink from extruding (and/or evaporating) out of reservoir  204  through venting system  206 . Venting system  206  is able to seal-off the reservoir as well as permit air to enter reservoir  204 , autonomously, as shall be described in more detail below with reference to  FIGS. 3 and 4 . Additionally, venting system  206  is able to operate when ink is in fluidic contact with it or not, e.g., when reservoir is only half full and the ink level is below venting system  206 . It should also be noted that venting system  206  is able to act in concert with ink delivery system  106 , i.e., allow air to enter chassis  202  when ink delivery system  106  is active and seal-off air/seal-in ink when system  106  is inactive. 
     In other words, autonomous venting system  206  allows air to enter vessel  104  when ink is being consumed by printing system  100 . When the printing system  100  is not consuming ink, generally autonomous venting system  206  prevents ink from drooling out during environmental excursions, such as created by thermal excusions and altitude changes. Typically, venting system  206  is located toward the top of vessel  104  as shown in  FIG. 2 , but may be incorporated into any other location on vessel  104  that permits adequate air supply. 
     Referring now to  FIG. 3 , is a cross sectional view of an exemplary autonomous venting system  206 . Venting system  206  includes: a vent hole  302 , a flexible diaphragm  304 , a diaphragm hole  306 , a sealing member  308 , and a valve encasement member  310 . Venting system  206  will now be described in more detail. 
     Extending through chassis  202  is vent hole  302 , which is located on the reservoir  204  side (or ink side) of chassis  202 . Vent hole  302  has a diameter equal to X, where X may be a multitude of sizes, dependent upon the size and type of vessel  104 . In the exemplary embodiment X=6.0 mm. Vent hole  302  in the exemplary illustration is round, but may be any shape. Although only one vent hole is shown in the exemplary illustration, more than one vent hole may be used in a vessel  104 , depending on the size and application of the container vessel. 
     A flexible diaphragm  304  is inserted to fit and extend over vent hole  302 , such that vent hole  302  is preferably fully covered. Accordingly, an interior side  316  of diaphragm  304  is either in fluid communication with ink stored in reservoir  204  and/or air, as ink is extracted from reservoir  204 . Whereas, an exterior side  318  of diaphragm  304  is in gas communication with atmospheric pressures caused by air. Diaphragm  304  should be constructed of a flexible non-porous material. In a preferred embodiment, diaphragm is composed of EPDM elastomer material, but other elastomer, or non-elastomer materials may also be substituted for EPDM, as would be appreciated by those skilled in the relevant art. It should also be noted that diaphragm  304  could be attached to the interior side of reservoir  204  and the vent hole could be on the exterior side of  318  of diaphragm  304 . 
     Located in the center of diaphragm  304 , is at least a single diaphragm hole  306  that is preferably smaller than the diameter of vent hole  302 . As shown in  FIG. 3 , the diameter of diaphragm hole  306  is X−L, where L is greater than 0. In the exemplary embodiment the diameter of diaphragm hole  306  is 1.2 mm. Also hole  306  is round, but may be non-circular as should be appreciated by those skilled in the art. It is also possible that more than one hole  306  of various sizes could be embedded into diaphragm  304 , without departing from the scope of the claimed invention. 
     A sealing member  308  is positioned to press against diaphragm  304 . In the exemplary embodiment sealing member  308  is positioned at the center of hole  306  and is a protruding domed shape piece of plastic, although other shapes are possible so long as the sealing member  308  provides a sealing fit when in full contact with diaphragm hole  306 . A domed surface sealing member  308  allows for loser tolerances of plastic molded parts. Sealing member  308  should preferably be rigid or semi-rigid and can be in a fixed stationary position. Of course, more than one sealing member  308  could be employed, depending on the size and quantity of diaphragm holes. Sealing member  308  should preferably have a shape similar to the diaphragm hole  306  to ensure a compatible fit. Although not shown due to the perspective of  FIG. 3 , sealing member  308  is actually connected as a fully integrated part with encasement member  310 . 
     Encasement member  310  is inserted in chassis  202  and is also positioned to fasten and seal the ends of diaphragm  304 , which in the exemplary embodiment is shown sandwiched between chassis  202  and encasement member  310 . At various locations in encasement member  310  are air holes  314  that provide a means for atmospheric pressure to be exerted against the exterior side  318  of diaphragm  304 . Additionally, air holes  314  provide a path for air to flow into vent hole  302  when the seal between sealing member  308  and diaphragm hole  306  is open. In the exemplary illustration there are four air holes  314  (see also FIG.  4 ). Generally, it is desirable to have enough air holes  314  to provide atmospheric pressure evenly at locations across diaphragm  304 , but the number of air holes chosen is a design choice of the skilled artisan. 
     The operation of autonomous air vent  206  will now be described in more detail. As mentioned above, diaphragm  304  is a flexible elastomer. When ink delivery system  106  is inactive sealing member  308  is pre-tuned to press against diaphragm  304  and therefore provide a seal of diaphragm hole  306 . Accordingly, when ink delivery system is inactive, air does not flow into or out of diaphragm hole  306 . Likewise, ink pressing on the interior side  316  of diaphragm  304  is prevented from escaping from reservoir  204  by venting system  206 . It is desirable to select a diaphragm thickness and tune the tension of diaphragm  304  so that temperature and altitude changes do not cause ink to weep out of diaphragm hole  306 , when ink delivery is inactive. 
     As ink delivery system  106  extracts ink from reservoir  204 , air will eventually crack the seal between sealing member  308  and diaphragm hole  306 . That is, hole  306  will stay sealed until the balance of pressure in vessel  104  reservoir  204  is negative enough to cause atmospheric air to enter diaphragm  304  via hole  306 . At this point, diaphragm  304  actually flexes away from sealing member  308  and toward the inside of reservoir  204 . This is caused by the greater atmospheric pressure exerted against an internal ink reservoir  204  pressure (e.g., negative reservoir pressure). Once there is a balance of pressures between (i) reservoir  204  exerted against the interior side  316  of diaphragm  304  and (ii) atmospheric pressure exerted on the exterior side of diaphragm  304 , due to air entering reservoir  204  via hole  306 , then the diaphragm should flex back to its pre-tuned tension position, resting against sealing member  308 . It is desirable to tune the tension on the diaphragm so that air flow is only able to bubble-in. 
     In other words, sealing member  308  is configured to press against and seal diaphragm hole  306  on the exterior side  318  of diaphragm  304  when the ink delivery system is inactive. On the other hand, diaphragm  304  flexes away from the sealing member  308  as negative pressure builds in reservoir  204  when delivery system  106  extracts ink from vessel  104 . Actually, atmospheric air pressure pushes against the exterior side  318  of diaphragm  306  and causes the diaphragm  304  to move away (i.e., flex) from sealing member  308 . This movement thereby actuates atmospheric air to flow into diaphragm hole  306  and through vent hole  302  and into vessel  104 . Valve encasement member  310  in conjunction with sealing member  308 , should provide enough atmospheric pressure via holes  314  (also referred to as an air chamber  314 ) so that there is enough air flow and/or pressure exerted around the sealing member  308  and the flexible diaphragm  304 . 
     Thus, autonomous venting system  206  opens and closes hole  306  based on differential pressures between those present on the exterior and interior sides  318 ,  316 , respectively, of diaphragm  304 . The venting system  206  is autonomous in that it regulates itself purely based on pressure differentials. No mechanically powered parts or control mechanism are needed to open or close the vessel&#39;s  104  vent  206 . The system  206  is low cost and brings many advantages to the designs of printing systems  100 , such as, but not limited to: free ink vessels (ink can reside in vessels without immersion venting systems such as porous material), minimized stranded residual ink (3% or less), environmentally safer containers, all plastic/rubber recyclable containers, higher volumetric capacities for containers and many other related advances. 
       FIGS. 4-5  collectively illustrate autonomous venting system  206  in greater detail.  FIG. 4  illustrates an exemplary cross-sectional view of autonomous venting system  206 .  FIG. 5  illustrates an exemplary topical view  400  of autonomous venting system  206  from the exterior of ink containment vessel  104 . As shown valve encasement member  310  is a large fitted plastic member that covers diaphragm  304 . Further, sealing member  308  is an integrated part of encasement member  310 , except it is molded inward (away from view in FIG.  5 ), to form the dome shape shown in  FIGS. 3-4 . Holes  314  provide the basis for air to enter the encasement member to provide the passageways for proper air flow and atmospheric pressure in the air chamber of  312  (shown in FIG.  4 ). Manufacturers of ink vessel  104  only need to purchase two parts in addition to chassis  202 : encasement member  310  and an elastomer disk for diaphragm  304 . Once tolerances are determined, assembly of vessel  104  can be performed with less expense than current printer cartridges used in most printing systems, such as ink-jet printers. 
     While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It may be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention as defined in the claim(s).