Abstract:
A solid printer includes a solid ink container that expels solid ink units in predetermined amounts for delivery to a melting device within the printer. The solid ink container includes a housing in which solid ink pellets are stored, an opening in the housing through which solid ink units are expelled, a first moveable member located within the housing proximate to the opening, the first moveable member being configured to move solid ink units through the opening, and a second moveable member located within the housing, the second moveable member being configured to move solid ink pellets to the first moveable member to enable the first moveable member to expel solid ink pellets through the opening in the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Cross reference is made to the following application: U.S. Ser. No. 12/016,675 (1776-0150) entitled “Transport System Having Multiple Moving Forces For Solid Ink Delivery In A Printer,” which was filed on Jan. 18, 2008, and which is owned by the assignee of the subject matter described below and is expressly incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The transport system disclosed below generally relates to solid ink printers, and, more particularly, to solid ink printers that uses solid ink pellets. 
       BACKGROUND 
       [0003]    Solid ink or phase change ink imaging devices, hereinafter called solid ink printers, encompass various imaging devices, such as printers and multi-function devices. These printers offer many advantages over other types of image generating devices, such as laser and aqueous inkjet imaging devices. Solid ink or phase change ink printers conventionally receive ink in a solid form, which is typically a block form known as ink sticks. A color printer typically uses four colors of ink (yellow, cyan, magenta, and black). 
         [0004]    The solid ink sticks, hereafter referred to as ink, sticks, or ink sticks, are delivered to a melting device, which is typically coupled to an ink delivery system, commonly referred to as a loader for conversion of the solid ink to a liquid. A typical ink loader includes multiple feed channels, one for each color of ink used in the imaging device. The ink for a particular color is placed in an insertion opening in the feed channel and then either gravity fed or urged by a conveyor or spring loaded pusher along the feed channel toward the melting device. The melting device heats the solid ink impinging on it and melts it into a liquid for delivery to a print head for jetting onto a recording medium or intermediate transfer surface. 
         [0005]    The operational speed of solid ink printers has increased in order to produce higher output rates for printed copies. As the output rates have increased so has the demand for melted ink within the printer. In an effort to reduce the melting time for solid ink sticks or pellets, the surface area of an ink stick or pellet that contacts a melting device has been increased. One way of increasing the surface area of solid ink sticks or pellets has been to make the pellets smaller. These smaller pellets, however, are not as easily handled by users as solid ink sticks that are typically the size of a wooden building block or larger. As the pellets approach the size of a small marble, BB, large grain, or the like, they are better stored in containers that can be opened and their contents emptied into a hopper within the machine, for example. Pellets would be stored in a cartridge, which may also be a component of an ink delivery system. One advantage of a cartridge is that ink particulates and smears that can affect ink feed reliability can be mitigated with replacement of the cartridge multiple times over the life of the product. 
         [0006]    Solid ink printers significantly differ from ink cartridge or toner printers because they need not be exhausted before additional solid ink is added to the feed channel. Specifically, ink cartridges and toner cartridges should be exhausted before another cartridge is installed so as not to waste ink or toner in a partially emptied cartridge. These cartridges may be typically returned to the manufacturer or other source to be refilled. Solid ink, on the other hand, may be stored on the premises and installed a stick at a time or as a group of pellets. Because the entire solid ink unit is consumed in the printing process, no housing or other component survives for disposal or return to the manufacturer. 
         [0007]    The requirement that solid ink remains solid until impinging upon the melting assembly does present some challenges not present in ink cartridge and toner cartridge printers. Because the ink loader is above the ambient room temperature, the ink softens. The softened ink requires more force to be applied to the ink to overcome the increased friction. Additionally, a limit exists for the temperature level in an ink loader in order to prevent the ink from becoming too soft and losing its shape in the loader. 
         [0008]    Containers for holding and dispensing solid ink from the ink loader, particularly pelletized solid ink, face some challenges. Traditional containers for pelletized material have been sealed at the time of manufacture such that they are only useful until the material has been dispensed. Once these containers are used, they become environmental waste with which an end-user must contend. Utilizing pelletized solid ink in larger products, such as a tabloid sized printer, is facilitated by employing very large containers and potentially multiple containers for some or all of the colors. These containers would be consistent with the space available in larger imaging products and the generally greater print volume they produce. These large machines are often placed under a lease agreement that includes a process for ink replacement and/or cartridge exchange. Smaller solid ink desk top printers and multi-function printers (MFPs) present a greater challenge in using pelletized ink supplied in cartridges Ink cartridges must not be so large that the purchase price presents an obstacle to users with lower volume demands. The cartridges may have to be replaced prior to being fully depleted to continue printing, as is common to toner cartridges, so some small remaining ink volume may remain in the cartridge when the cartridge is removed from the product for replacement. This ink could easily escape the cartridge through the exit port that enables the ink pellets to enter the ink delivery system. The warm printer environment encourages solid ink to become sticky such that force is usually required for the feeding of the ink. Small cartridges can be designed to be refilled but the present objective of cartridge mechanisms is to ensure reliable, consistent feed and not be prone to disagreeable leakage when removed from the printer. These issues present challenges that previous solutions have not addressed. 
       SUMMARY 
       [0009]    The limitations on storing and delivering pelletized solid ink to a melting device for a solid ink printer have been addressed by a container that uses a motive force to deliver solid ink pellets to a gate that controls the release of the solid ink pellets to an external ink delivery or melting device of a solid ink printer. The pellet container includes a housing having an opening through which multiple solid ink pellets are expelled, a first moveable member located within the housing proximate to the opening, the first moveable member being configured to move solid ink units through the opening, and a second moveable member located within the housing, the second moveable member being configured to move solid ink pellets within the housing to the first moveable member for expulsion from the housing through the opening in the housing by the first moveable member. 
         [0010]    A solid ink printer incorporates a solid ink container that enables replacement of the container without loss of solid ink pellets from the container. The printer includes a melting device configured to melt solid ink pellets and produce liquid ink for printing, and a solid ink container, the solid ink container being configured to mount selectively to the solid ink printer and further including a housing having a volume in which solid ink pellets are stored, an opening in the housing through which solid ink pellets are expelled for delivery of the solid ink pellets to the melting device, a first moveable member located within the housing proximate to the first opening, the first moveable member being configured to move solid ink pellets through the opening in the housing, and a second moveable member configured to move solid ink pellets within the housing to the first moveable member for expulsion from the housing through the opening in the housing by the first moveable member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Features for transporting solid ink in a solid ink printer are discussed with reference to the drawings, in which: 
           [0012]      FIG. 1  is a perspective view of a solid ink printer incorporating the solid ink container shown in  FIG. 2 ; 
           [0013]      FIG. 2  is a cross-sectional view of a solid ink container that may be used with the printer shown in  FIG. 1 ; 
           [0014]      FIG. 3  is a cross-sectional view of another embodiment of a solid ink container that may be used with the printer shown in  FIG. 1 , in this configuration an optional refill opening is included; and 
           [0015]      FIG. 4 . is a front cross-sectional view of the printer shown in  FIG. 1  front cross-sectional view of the printer shown in  FIG. 1  incorporating the solid ink container of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    The term “printer” refers, for example, to reproduction devices in general, such as printers, facsimile machines, copiers, and related multi-function products. While the specification focuses on a system that transports solid ink through a solid ink printer, the transport system may be used with any solid ink image generating device. The cartridge of the present device is described as containing and feeding solid ink in the form of pellets. As used in this context, the term pellet or pellets refers to small chunks, rounds, pastilles, or granular ink where the material could flow out of a common liter size container rather having to be picked up and placed individually by a user. 
         [0017]    An exemplary solid ink printer having a solid ink transport system described in this document is shown in  FIG. 1 . The printer  10  includes a housing  32  having four vertically standing side walls  12 A,  12 B,  12 C, and  12 D, a bottom surface  14 , and a top surface  18 . Although the printer  10  is depicted in a shape that may be described as a rectangular solid, other shapes are possible. Additionally, the surfaces of the housing need not be planar and may include depressions and/or protrusions to accommodate internal components or enhance the visibility of external features. The housing may also include a control panel  26  having a display  24  and one or more function keys  22  or other control actuators or indicators. 
         [0018]    The upper surface  18  of the housing  32  may include, for example, an output tray  16 . Recording media, such as a paper sheet  20 , exit the housing  32  and rest in the output tray  16  until retrieved by a user or operator. The housing  32  may include a media supply tray (not shown) from which recording media may be removed and processed by the printer  10 . While the output tray  16  is shown as being in the upper surface  18  of the housing  32 , other positions are possible, such as extending from rear wall  12 D or one of the other side walls. 
         [0019]    As shown in  FIG. 1 , an enclosed ink loader  28  includes an access door  30  in the housing  32 . Although the door  30  is depicted as being in the side wall  12 A, it may be located in one of the other side walls or in the upper surface  18 . Door  30  may be opened by the user of printer  10  to insert or remove a solid ink container such as depicted in  FIG. 2  and  FIG. 3  below. The example embodiment depicts door  30  opening on hinges  34 , with a handle  36  allowing the user to engage the door  30 . Many alternative embodiments of the ink loader  28  are envisioned. Some include a door that is slidably opened and closed or pivoted from an upper or lower hinge. Additionally, a locking mechanism may be included in embodiments where access to the solid ink container is restricted. In other embodiments, the ink loader may be positioned on the exterior of the housing  32  or otherwise mounted outside of the housing. 
         [0020]    An example embodiment of an ink container that may be used with the printer  10  of  FIG. 1  is depicted in  FIG. 2 . The ink container  200  includes an auger  204  that has a central axle  222  rotationally mounted to a housing  202 . The rotating auger  204  acts as a conveyor, moving solid ink pellets  208  towards a vaned rotor  212 . In the embodiment of  FIG. 2 , vaned rotor  212  is coaxially mounted to the central axle  222 , and rotates in the same direction as the auger  204 . When vaned rotor  212  rotates, ink pellets  208  are deposited in the chambers between each vane, and as vaned rotor  212  rotates past ink exhaust opening  214 , the solid ink pellets  208  exit the ink container  200 . In order to regulate the number of ink pellets  208  being conveyed to each chamber in vaned rotor  212 , a restrictor ledge  216  is placed over vaned rotor  212 . The restrictor ledge  216  relieves pressure on the solid ink pellets  208  and helps prevent the ink pellets from jamming vaned rotor  212 . The auger  204  is tapered as shown at  217  at the portion of auger  204  proximate the restrictor ledge  216  and the vaned rotor  212 . This structure helps reduce the number of pellets presented to the chambers of the rotor  212  and also reduces pressure on the pellets being carried by the auger to minimize the opportunity for jamming. When the central axis is not rotating, the vanes of rotor  212  act as a closed gate. The closed gate prevents solid ink pellets  208  from leaking out of ink exhaust opening  214  when the container is removed. In operation, the central axle  222 , auger  204 , and vaned rotor  212  are rotated by an external actuator (shown in  FIG. 4 ) that engages with a drive coupler  220  to selectively dispense solid ink pellets  208  from the container  200 . The auger and vaned rotor may be driven as a unit or independently at equivalent or different speeds or for equivalent or different time periods. 
         [0021]    An alternative embodiment of an ink container that may be used with the printer  10  of  FIG. 1  is depicted in  FIG. 3 . The ink container  300  includes a conveyor assembly  304  that includes an endless conveyor belt  306  rotated by cogs  305 . While the conveyor belt  306  depicted in  FIG. 3  is smooth, alternative belts could have textured corrugated surfaces that aid in conveying the ink pellets. The conveyor assembly  304  conveys solid ink pellets  308  towards a vaned rotor  312 . In the embodiment of  FIG. 3 , the rotation axis of the vaned rotor  312  is oriented transversely to the direction of pellet movement along the conveyor belt  306 . When the vaned rotor  312  rotates, ink pellets  308  are deposited in the chambers between each vane, and as vaned rotor  312  rotates past ink exhaust opening  314 , the solid ink pellets  308  exit the ink container  300 . In order to regulate the number of ink pellets  308  being conveyed to each chamber in vaned rotor  312 , a restrictor wheel  316  is positioned above the opening leading to the vaned rotor  312 . The restrictor wheel limits the amount of space available to the solid ink pellets  308  as they enter a chamber of the vaned rotor  312 . The restrictor wheel  316  relieves pressure on the ink pellets being directed to the vane and so reduces the packing force on the pellets. This reduction mitigates the possibility of the pellets clogging the ink exhaust opening  314 . In one embodiment, the restrictor wheel  316  is compliant and may be discontinuous, with vanes, for example. The wheel  316  may also be formed from a flexible material, such as foam, in order to accommodate the solid ink pellets  308 . When the vaned rotor  312  is not rotating, the vanes of vaned rotor  312  act as a closed gate, preventing solid ink pellets  308  from leaking out of ink exhaust opening  314 . In operation, the central axle  311  of the vaned rotor, and the central axle  303  of at least one of the cogs  305  engages with an external actuator that selectively rotates the vaned rotor  312  and cogs  305 , causing ink pellets  308  to be dispensed from ink exhaust port  314 . The conveyer and vaned rotor may be driven as a unit or driven independently at equivalent or different speeds or for equivalent or different time periods. 
         [0022]    Continuing to refer to  FIG. 3 , the ink pellets  308  are stored in a storage space  336 . While the depiction of the example embodiment of  FIG. 3  does not show a full ink container  300 , the ink pellets may fill the storage space  336  up to the top ink loading opening  332 . The cartridge shown in  FIG. 3  includes an ink loading opening  332  that enables the ink container  300  to be refilled with solid ink pellets  308 . A door  324  is slidably disposed across the ink loading opening  332  to allow an end user to open or close the ink container  300  for loading. When closed, the door  324  engages with a back stop  328 , sealing the storage space  336 . The arrangement of  FIG. 3  allows for the ink container  300  to be refilled by the user at any time, including when the ink container  300  is partially full. Thus, an end user is able to remove the ink container  300  from the printer, “top off” the pellet supply stored in the container, and re-install the ink container  300  in the printer without losing pellets from the exit of the container. The loading door and refill function are optional and may or may not be an aspect of any configuration of an ink pellet cartridge. 
         [0023]    The ink containers depicted in  FIG. 2  and  FIG. 3  are merely illustrative of possible embodiments for solid ink containers, and other variations are envisioned. For example, the covering the ink loading opening could use a hinged mechanism instead of a sliding mechanism. The opening could also include a threaded screw attachment designed to accept a cap or be configured to open only with specialized factory equipment to prevent unauthorized access. The refill door or opening may be associated with one or more structural features that enable access to the internal volume of the container only by damaging some portion of the cartridge assembly. Thus, replacement of one or more container components with new parts would be required after a refill with pellets. For example, some frangible component may be associated with the door that fractures upon the opening of the refill door. Various considerations including selections of materials used, operating temperatures, size and shapes of the solid ink pellets, friction between the ink pellets and container, desired ink pellet output rate, and the size and shape of the ink container may all affect the selection and configuration of the components used. Additionally, the cartridge may have aesthetic treatments if mounted so as to be visible in a normal printer operation state. The housing or any other cartridge element may be transparent, translucent or opaque and may be colored to indicate the general color of the ink. 
         [0024]    An internal view of the example printer  10  of  FIG. 1  is depicted in  FIG. 4 . The print engine  40  includes the imaging system with print head  56 , and other various subsystems, such as the internal media transport and imaging surface maintenance systems (not shown). The ink cartridge outlet path  58  is coupled at one end to the ink container  200  and at the other end to an ink melting assembly  38 . The ink outlet path  58  may be configured as a tube, which can be of any functional cross sectional shape, or a trough, for example, to contain the solid ink pellets  78  as they move along the ink outlet path  58 . As shown in  FIG. 2 , the ink outlet path is oriented so it uses a gravity feed employing a vertical drop. This vertical drop may be at an angle with respect to the bottom surface  14  or it may be essentially a straight drop towards the bottom surface. The vertical drop helps ensure that gravity is the primary or most significant influencing force that moves the solid ink from the ink container  200  to the melt device  60 . Gravity feed as used herein refers to a force that moves solid ink with gravity alone or that uses gravity to augment another motive force acting on the solid ink or that enables another motive force to move solid ink along a path. 
         [0025]    Continuing to refer to  FIG. 4 , solid ink pellets  78  arrive at ink melting assembly  38  that includes a melt device  60 . Typical melt devices are metallic or ceramic plates that are heated by passing electrical current through a pattern of electrical conductive traces on the plate&#39;s surface. This type of heater may be an assembly of resistive traces and laminated insulating layers and may be affixed to a plate with adhesive. The melt device  60  is electrically connected to a controller  68  that selectively couples electrical current to the melt plate with reference to various factors that may include, for example, the printer&#39;s operational mode and the temperature of ink in the ink melting assembly  38 . The melted ink is stored in a reservoir that may be integrated into the print head  56 . 
         [0026]    In the example of  FIG. 4 , the ink container  200  emits solid ink pellets  78  in response to having its auger and vaned rotor rotated by electromechanical actuator  64 . A drive shaft of electromechanical actuator  64  engages the drive coupler  220  of the ink container  200 . The coupler causes both the vaned rotor and auger in the in container  200  to rotate in response to the rotation of electromechanical actuator  64 . This actuator is electrically connected to a controller  68  that controls when the actuator rotates in order to effectively supply ink to print head  56 . When the actuator  64  activates, the ink container  200  releases solid ink pellets  78 . When the ink container is removed, the auger disengages from the actuator  64  so the vaned rotor  212  of  FIG. 2  remains stationary and solid ink pellets are prevented from escaping the ink container  200 . 
         [0027]    Melted ink may be dripped directly from the melt device into a receiving reservoir or it may flow or be conveyed through a non-pressurized channel. Alternative embodiments may employ sealed pathways for ink transfer through all or portions of the path leading to the printhead. When sealed sections are used, ink may be pressurized to facilitate rapid flow or other desirable performance, such as passing through a filter. In a color printer using more than one type of ink, a separate ink container  200  may be used for each ink color, and the multiple ink containers may each be inserted into the printer using the loader  28 . 
         [0028]    It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may by desirably combined into many other different systems or applications. Also, that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.