Abstract:
Techniques for liquid replenishment in a printer/plotter. An ink delivery system (IDS) is employed wherein the on-carriage spring reservoir of the print cartridge is manually and securely connected to the off-carriage reservoir. A pen cartridge that uses an internal spring to provide vacuum pressure is connected from an inlet port through a unitary coupler to an ink reservoir located off the scanning carriage axis. The coupler serves to align as well as to secure two mating valves to securely hold them together in an open latched position which is not intended to be modified or disconnected until the entire ink supply has been depleted. A replaceable ink supply module for providing replenishment of an inkjet printhead includes a collapsible bag, an enclosure box, a connective tube, and an on/off valve. These four components are incorporated into a composite sealed system which remains intact during shipment, storage, installation and operation. The collapsible bag is placed inside the protective enclosure box and has an end-connect outlet permanently attached to one end of the connective tube. The other end of the connective tube carries a permanently attached on/off valve designed for engagement with an inlet valve of an inkjet printhead.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. Ser. No. 09/670,608, filed Sep. 26, 2000 now abandoned, in turn a continuation-in-part of U.S. Ser. No. 09/045,150, filed Mar. 19, 1998, in turn a continuation-in-part of U.S. Ser. No. 08/615,903 filed Mar. 14, 1996 by Scheffelin et al. entitled “Inkjet Print Cartridge Having Two Ink Inlet Ports For Initial Filling And Recharging” now U.S. Pat. No. 5,777,648 which is a continuation-in-part of Ser. No. 08/322,848 filed Oct. 13, 1994, now U.S. Pat. No. 5,621,445 which is a continuation-in-part of Ser. No. 08/171,321 filed Dec. 21, 1993, now abandoned, which is a continuation of Ser. No. 07/750,360 filed Aug. 27, 1991, now U.S. Pat. No. 5,280,300; said Ser. No. 08/615,903 is also a continuation-in-part of Ser. No. 08/503,756 filed Jul. 18, 1995, now abandoned, which is a continuation of Ser. No. 07/995,108 filed Dec. 22, 1992, now U.S. Pat. No. 5,434,603 which is a continuation-in-part of Ser. No. 07/717,735 filed Jun. 16, 1991 now U.S. Pat. No. 5,359,353. Application Ser. No. 09/045,150 is also a continuation-in-part of U.S. Ser. No. 08/454,975 filed May 31, 1995 by Scheffelin et al. entitled “Continuous Refill Of Spring Bag Reservoir In An Ink-Jet Swath Printer/Plotter” now U.S. Pat. No. 5,745,137 which is a continuation-in-part of Ser. No. 07/995,851 filed Dec. 23, 1992, now U.S. Pat. No. 5,757,406 which is a continuation-in-part of Ser. No. 07/929,615 filed Aug. 12, 1992, which subsequently issued as U.S. Pat. No. 5,767,882 through file wrapper continuing application Ser. No. 08/240,297, which are incorporated by reference herein. Application Ser. No. 09/045,150 is also a continuation-in-part of U.S. Ser. No. 08/726,587 filed Oct. 7, 1996 by Max S. Gunther, Mark E. Young, David S. Hunt, et al. entitled “Inkjet Cartridge Fill Port Adapter”, now issued as U.S. Pat. No. 5,874,976. All three parent cases are commonly assigned to the assignee of the present application. 
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     Other more recent co-pending commonly assigned related applications are Ser. No. 09/045,151, now U.S. Pat. No. 6,059,401, “Alignment Coupling Device For Manually Connecting An Ink Supply To An Inkjet Print Cartridge” filed Mar. 19, 1998 by Paul S. Wu et al., and Ser. No. 09/045,148, now U.S. Pat. No. 6,120,132, “Assembly Technique Using Modular Ink Delivery Components For Installation In An Inkjet Printer” filed Mar. 19, 1998 by Erich E. Coiner et al., both of which are incorporated by reference herein. 
     A previously filed co-pending commonly assigned application related to this application is Ser. No. 08/454,975 filed May 31, 1995 by Joseph E. Scheffelin et al. (the “&#39;975 application”) entitled CONTINUOUS REFILL OF SPRING BAG RESERVOIR IN AN INK-JET SWATH PRINTER/PLOTTER, which is incorporated herein by reference. 
     Other more recent co-pending commonly assigned related applications are Ser. No. 08/726,587, INKJET CARTRIDGE FILL PORT ADAPTOR, filed Oct. 7, 1996, by Max S. Gunther et al.; Ser. No. 08/810,485, INKJET PRINTING WITH REPLACEABLE SET OF INK-RELATED COMPONENTS etc., filed Mar. 3, 1997, by Rick Becker, et al.; Ser. No. 08/805,859, REPLACEABLE INK SUPPLY MODULE (BAG/BOX/TUBE/VALVE) etc., filed Mar. 3, 1997, by Elizabeth Zapata, et al.; Ser. No. 08/805,860, SPACE EFFICIENT ENCLOSURE SHAPE FOR NESTING TOGETHER A PLURALITY OF REPLACEABLE INK SUPPLY BAGS, filed Mar. 3, 1997, by Erich Coiner, et al.; Ser. No. 08/810,840, PRINTING SYSTEM WITH SINGLE ON/OFF CONTROL VALVE etc., filed Mar. 3, 1997 by Max S. Gunther, et al.; Ser. No. 08/805,861, INTERCHANGEABLE FLUID INTERCONNECT ATTACHMENT AND INTERFACE, filed Mar. 4, 1998 by Max S. Gunther; all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates to inkjet printers and more particularly to an inkjet print cartridge which can be recharged with ink. 
     BACKGROUND OF THE INVENTION 
     A popular type of inkjet printer contains a scanning carriage for supporting one or more disposable print cartridges. Each disposable print cartridge contains a supply of ink in an ink reservoir, a printhead, and ink channels which lead from the ink reservoir to ink ejection chambers formed on the printhead. An ink ejection element, such as a heater resistor or a piezoelectric element, is located within each ink ejection chamber. The ink ejection elements are selectively fired, causing a droplet of ink to be ejected through a nozzle overlying each activated ink ejection chamber so as to print a pattern of dots on the medium. When such printing takes place at 300 dots per inch (dpi) or greater, the individual dots are indistinguishable from one another and high quality characters and images are printed. 
     Once the initial supply of ink in the ink reservoir is depleted, the print cartridge is disposed of and a new print cartridge is inserted in its place. The printhead, however, has a usable life which outlasts the ink supply. Methods have been proposed to refill these single-use-only print cartridges, but such refilling techniques require penetration into the print cartridge body in a manner not intended by the manufacturer and typically require the user to manually inject the ink into the print cartridge. Additionally, the quality of the refill ink is usually lower than the quality of the original ink. As a result, such refilling frequently results in ink drooling from the nozzles, a messy transfer of ink from the refill kit to the print cartridge reservoir, air pockets forming in the ink channels, poor quality printing resulting from the ink being incompatible with the high speed printing system, and an overall reduction in quality of the printed image. 
     What is needed is an improved structure and method for recharging the ink supply in an inkjet print cartridge which is not subject to any of the above-mentioned drawbacks of the existing systems. 
     SUMMARY OF THE INVENTION 
     A new ink delivery system (IDS) for printer/plotters has been developed wherein the on-carriage spring reservoir of the print cartridge is manually and securely connected to the off-carriage reservoir. 
     This invention optimizes the performance of this new off-carriage continuous ink delivery system. In this type of IDS, a pen cartridge that uses an internal spring to provide vacuum pressure is connected from an inlet port through a unitary coupler to an ink reservoir located off the scanning carriage axis. The coupler serves to align as well as to secure two mating valves to securely hold them together in an open latched position which is not intended to be modified or disconnected until the entire ink supply has been depleted. 
     A replaceable ink supply module for providing replenishment of an inkjet printhead includes a collapsible bag, an enclosure box, a connective tube, and an on/off valve. These four components are incorporated into a composite sealed system which remains intact during shipment, storage, installation and operation. The collapsible bag is placed inside of the protective enclosure box and has an end-connect outlet permanently attached to one end of the connective tube. The other end of the connective tube carries a permanently attached on/off valve designed for engagement with an inlet valve of an inkjet printhead. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     These and other features and advantages of the present invention will become more apparent from the following detailed description of an exemplary embodiment thereof, as illustrated in the accompanying drawings, in which: 
     FIG. 1 is a perspective view of an inkjet printer incorporating an embodiment of an inkjet print cartridge. 
     FIG. 2 is a perspective view of a preferred embodiment of a print cartridge being supported by a scanning carriage in the printer of FIG.  1 . 
     FIG. 3 is a perspective view of a preferred embodiment of a print cartridge incorporating a refill valve. 
     FIG. 4 is a different perspective view of the print cartridge of FIG.  3 . 
     FIG. 5 is a close-up view of one type of refill valve on the print cartridge of FIG.  3 . 
     FIG. 6 is an isometric view of an ink-jet print cartridge usable in the system of FIG. 1, with a refill platform housing portion, a needle valve, and supply tube in exploded view. 
     FIG. 7 is a cross-sectional view taken along line  7 — 7  of FIG. 6, showing the valve structure in a disengaged position relative to a refill port on the print cartridge. 
     FIG. 8 is a cross-sectional view similar to FIG. 7, but showing the valve structure in an engaged position relative to the refill port of the print cartridge. 
     FIG. 9 is a bottom perspective view of a preferred embodiment of an alignment coupler. 
     FIG. 10 shows a metal sleeve used on the ink supply valve. 
     FIG. 11 shows the coupler mounted on a printhead frame, with an ink supply valve ready to be manually inserted to the position shown in phantom lines. 
     FIG. 12 is a side view of a printhead packaged in its shipping sleeve with the coupler already mounted on the printhead frame. 
     FIG. 13 is a top view taken along the line  13 — 13  in FIG.  12 . 
     FIG. 14 is a sectional side view of the coupler. 
     FIG. 15 is a side view of a transparent coupler installed on the printhead frame, showing the gripping handle of the printhead which incorporates the inlet port. 
     FIG. 16 is a sectional end view of the coupler. 
     FIG. 17 is a top view of the coupler. 
     FIG. 18 is a sectional view of the coupler mounted on the printhead frame, showing the ink valve partially inserted into the coupler. 
     FIG. 19 is a sectional view like FIG. 18 showing the ink supply valve completely inserted into the coupler. 
     FIG. 20 is a top view of the gripping handle of the printhead showing the septum of the inlet port in closed position. 
     FIG. 21 is a bottom view of a presently preferred off-carriage ink supply module. 
     FIG. 22 is a perspective view of an alternate embodiment inkjet printer where hoses are connected between the valves of the print cartridges and a separate ink supply to refill the print cartridges. 
     FIG. 23 is a close-up view of the valve portion of the print cartridge having a hose extending therefrom. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates an inkjet printer  10  incorporating the preferred embodiment rechargeable print cartridge. Inkjet printer  10  itself may be conventional. A cover  11  protects the printing mechanism from dust and other foreign objects. A paper input tray  12  supports a stack of paper  14  for printing thereon. The paper, after printing, is then deposited in an output tray  15 . 
     In the embodiment shown in FIG. 1, four print cartridges  16  are mounted in a scanning carriage  18 . Print cartridges  16  contain black cyan, magenta, and yellow ink respectively. Selective activation of the ink firing elements in each of the four print cartridges  16  can produce a high resolution image in a wide variety of colors. In one embodiment, the black inkjet print cartridge  16  prints at 600 dots per inch (dpi), and the color print cartridges  16  print at 300 dpi. 
     The scanning carriage  18  is slideably mounted on a rod  20 . and carriage  18  is mechanically scanned across the paper, using a well-known belt/wire and pulley system, while print cartridges  16  eject droplets of ink to form printed characters or other images. Since the mechanisms and electronics within printer  10  may be conventional, printer  10  will not be further described in detail. 
     FIG. 2 is a more detailed view of the scanning carriage  18  housing print cartridges  16 . Carriage  18  moves in the direction indicated by arrow  22 , and a sheet of paper  14  moves in the direction of arrow  23  perpendicular to the direction of movement of carriage  18 . 
     Each print cartridge  16  is removable and engages with fixed electrodes on carriage  18  to provide the electrical signals to the printheads within each of print cartridges  16 . Each of print cartridges  16  contains a valve  24  which may be opened and closed. In an open state, ink from an external ink supply may flow through valve  24  and into the ink reservoir within print cartridge  16 . Valve  24  is surrounded by a cylindrical plastic sleeve  26 , which generally forms part of a handle  23  for allowing the user to easily grasp print cartridge  16  for insertion into and removal from carriage  18 . 
     FIG. 3 shows one perspective view of the preferred embodiment print cartridge  16 . Elements labeled with the same numerals in other figures are identical. The outer frame  30  of print cartridge  16  is formed of molded engineering plastic such as the material marketed under the trademark “NORYL” by General Electric Company. Side covers  32  may be formed of metal or plastic. Datums  34 ,  35 , and  36  affect the position of the print cartridge  16  when installed in carriage  18 . 
     In the preferred embodiment, nozzle member  40  consists of a strip of flexible tape  42  having nozzles  44  formed in the tape  42  using laser ablation. 
     Plastic tabs  45  are used to prevent a particular print cartridge  16  from being inserted into the wrong slot in carriage  18 . Tabs  45  are different for the black, cyan, magenta, and yellow print cartridges. 
     A fill hole  46  is provided for initially filling the ink reservoir in print cartridge  16  by the manufacturer. This hole  46  is later sealed with a steel ball, which is intended to be permanent. Such filling will be described later. 
     FIG. 4 is another perspective view of print cartridge  16  showing electrical contact pads  48  formed on the flexible tape  42  and connected via traces, formed on the underside of tape  42 , to electrodes on the printhead substrate affixed to the underside of tape  42 . 
     A tab  49  engages a spring-loaded lever  50  (FIG. 2) on carriage  18  for locking print cartridges  16  in place in carriage  18 . 
     FIG. 5 is a close-up of the print cartridge valve  24  surrounded by the cylindrical sleeve  26 , forming part of handle  28 . Support flanges  52  provide added support for handle  28 . 
     A printing system is described in the commonly assigned patent application entitled CONTINUOUS REFILL OF SPRING BAG RESERVOIR IN AN INK-JET SWATH PRINTER/PLOTTER which employs off-carriage ink reservoirs connected to on-carriage print cartridges through flexible tubing. The off-carriage reservoirs continuously replenish the supply of ink in the internal reservoirs of the on-carriage print cartridges, and maintain the back pressure in a range which results in high print quality. 
     The 975&#39; application describes a negative pressure, spring-bag print cartridge which is adapted for continuous refilling. FIGS. 6-8 show an ink-jet print cartridge  100 , similar to the cartridges described in the &#39;975 application, but which is adapted for intermittent refilling by addition of a self-sealing refill port in the grip handle of the cartridge. The cartridge  100  illustrates the cartridges  16  of the system of FIG.  1 . The cartridge  100  includes a housing  102  which encloses an internal reservoir  104  for storing ink. A printhead  106  with ink-jet nozzles is mounted to the housing. The printhead receives ink from the reservoir  104  and ejects ink droplets while the cartridge scans back and forth along a print carriage during a printing operation. A protruding grip  108  extends from the housing enabling convenient installation and removal from a print carriage within an ink-jet printer. The grip is formed on an external surface of the housing. 
     FIGS. 6-8 show additional detail of the grip  108 . The grip includes two connectors  110 ,  112  on opposing sides of a cylindrical port  114  which communicates with the reservoir  104 . The port is sealed by a septum  116  formed of an elastomeric material. The septum  116  has a small opening  118  formed therein. The grip with its port  114  is designed to intermittently engage with a needle valve structure  120  connected via a tube  122  to an off-carriage ink reservoir such as one of the reservoirs  80 - 86  of the system of FIG.  1 . FIG. 7 shows the valve structure  120  adjacent but not engaged with the port  116 . FIG. 8 shows the valve structure  120  fully engaged with the port. As shown in FIG. 8, the structure  120  includes hollow needle  122  with a closed distal end, but with a plurality of openings  124  formed therein adjacent the end. A sliding valve collar  128  tightly fits about the needle, and is biased by a spring  126  to a valve closed position in FIG.  7 . When the structure  120  is forced against the port  116 , the collar is pressed up the length of the needle, allowing the needle tip to slide into the port opening  118 , as shown in FIG.  8 . In this position, ink can flow through the needle openings  124  between the reservoir  104  and the tube  130 . Thus, with the cartridge  100  connected to an off-carriage reservoir via a valve structure such as  120 , a fluid path is established between the print cartridge and the off-carriage reservoir. Ink can flow between the off-carriage ink reservoir to the cartridge reservoir  104 . When the structure  120  is pulled away from the handle  108 , the valve structure  120  automatically closes as a result of the spring  126  acting on the collar  128 . The opening  118  will close as well due to the elasticity of the material  116 , thereby providing a self-sealing refill port for the print cartridge. 
     FIGS. 6-8 illustrate a locking structure  172  for releasably locking the valve  120  into the refill arm  170  at socket  174 . The structure  172  has locking surfaces  172 B (FIG. 7) which engage against the outer housing of the valve body  120 A. The structure is biased into the lock position by integral spring member  172 A (FIGS.  7  and  8 ). By exerting force on structure  170  at point  170 C (FIGS. 7 and 8) the spring is compressed, moving surface  172 B out of engagement with the valve body, and permitting the valve to be pulled out of the refill arm socket. This releasing lock structure enables the valve and reservoir to be replaced quickly as a unit. 
     An ink printing system is described herein which includes an inkjet printer, a removable print cartridge having an ink reservoir, an initial fill port, and a refill valve, and an ink refill system for engaging the print cartridge&#39;s refill valve and transferring ink to the ink reservoir. 
     The print cartridge includes a handle which is used to facilitate insertion of the cartridge into, and removal of the cartridge from, a scanning carriage in the printer. The refill valve in the print cartridge is contained with the handle of the print cartridge. This location of the refill valve provides performance and manufacturing advantages. 
     The details of the alignment coupler of the preferred embodiment are clearly shown in FIGS. 9-20 as well as the related parts of the inlet port of the printhead reservoir and the outlet valve of the ink supply. The individual parts will be identified, and then their operation explained. 
     The coupler  401  includes an outer shell  400 , a curved end wall  402  for engaging a matching curved frame  404  on the printhead, a straight end wall  406  for engaging a matching straight frame  408  on the printhead, elongated corner guides  410  each having a raised level land  412 , side alignment guides  414  each having twin raised lands  416  which terminate into dual fingers  418  slanted inwardly from opposite end walls  402 ,  406  for engaging a small diameter slot  419  on the inlet valve, and locking ledges  420  with concave recesses  422  on opposite side walls  423  for engaging cutouts and cylindrical walls respectively on the printhead handle  425 . The fingers  418  act like an arm which moves back and forth to receive and then lock in the slot  419 , the inlet valve, while the entire side walls  423  expand to allow the locking ledges  420  to receive and then lock in the handle  425  of the printhead. 
     The printhead handle  425  includes a septum  424  having a central dimple  426  for helping the needle valve  122  of the ink supply to pass through normally closed path  428  of the septum, as more fully described in connection with FIGS. 6-8. A metallic sleeve  430  provides the additional diameter needed on the ink supply valve to provide proper alignment of the valve interconnections. 
     Consistent with the goals of the invention in the preferred embodiment of FIGS. 9-20, the printhead and ink supply are permanently connected through the coupler  401  by the end user prior to operating the printer. Back pressure for proper operation is provided by locating the spring bag printhead reservoir adjacent to and in communication with the nozzle plate of the printhead. 
     It was a major design objective to leverage and take advantage of as much existing hardware as possible such as from the intermittent refilling embodiment of FIGS. 6-8. This objective was met by utilizing a printhead body with the rubber septum refill port and an off-carriage ink reservoir with valve. 
     Other important goals that have been achieved in the preferred embodiment of FIGS. 9-20 include the development of a simple connection scheme that an end user can use intuitively without any training. Also, allowing the ink supply valve to rotate freely with respect to the printhead body after the aforementioned connection has been made by the coupler. Further, maintaining a radial alignment of 0.95 mm between the tip of the needle on the ink supply valve and the center of the dimple on the septum of the inlet port for the printhead body. This is required to ensure that an air-tight fluid connection is made. Exceeding this alignment tolerance results in a defective fluid interconnection with a rubber of the septum stretching over the tip of the needle like a finger cot on a finger. This alignment is facilitated by the structural features of the alignment coupler during the entire time period while the user is holding the valve and inserting it into the printhead body. 
     Prolonged insertion of the needle into the septum causes the septum to take a “compression set”. If the needle is removed, the pen will ingest air, lose backpressure and begin leaking ink. This required that the valve interconnection be as tamper-proof and permanent as possible. 
     The alignment coupler  401  snap fits over existing features on the handle area of the printhead body. It contains a circular opening shown schematically in FIG. 11, with cylindrical features such as guides  410 ,  414  to provide alignment of the valve needle to the septum  116 . It also has cantilevered fingers  418  that “snap” into an existing groove such as slot  419  on the ink supply valve  120 . This provides permanent latched retention of the ink supply valve in the inlet port  114  of the printhead with the ink supply valve and matching inlet valve  120  held in open position whether or not the printer is in active, dormant or overnight storage mode. The metal sleeve  430  fits over the end of the ink supply valve  120  and increases the diameter of the front part of the valve. A diameter of 14.6 mm was required to ensure that the alignment goal of plus or minus 0.95 mm was met. This could also have been achieved by changing the valve design to have one larger diameter. This would have made the new valve design incompatible with the existing manufacturing equipment. To maintain compatibility, a separate part is added to the ink supply valve  120 . 
     Thus it will be appreciated by those skilled in the art that the invention does achieve the objectives of providing a high reliability fluid connection that is made by the end user and takes advantage of related ink component features and manufacturing processes. However, such features did require modification since the printhead frame of the preferred embodiment does not by itself provide any features suitable for aligning the ink supply valve to the rubber septum in the inlet port within the required plus or minus 0.95 mm tolerance. To overcome this deficiency, the unique alignment coupler was developed, and is preferably installed on the printhead frame before the customer receives the unit, such as in the factory. 
     The alignment coupler could have easily been installed on the pen frame on the main manufacturing line. Unfortunately, the packaging equipment that places the printhead into its shipping sleeve could not handle a printhead with an alignment coupler already installed. In order to address this issue we created a printhead shipping sleeve that has a corner notch which allows access to the handle region of the printhead. The alignment coupler is attached while the printhead is in its shipping sleeve. The exposed coupler is protected by a kit box that holds both the printhead and the modular ink reservoir. 
     FIGS. 22 and 23 illustrate an alternative embodiment which provides either a continuous refill of ink bag  51  within print cartridge  16  or intermittent filling of each print cartridge  16  during various times that printer  10  is activated. 
     Printer  10  in FIG. 22 may be identical to that shown in FIG. 1 but further houses a replaceable ink reservoir  202 , shown in dashed outline, containing black, cyan, magenta, and yellow ink for the four print cartridges  16  supported in scanning carriage  18 . 
     Hoses  204  contains valves and are engageable and disengageable from valve  24  in print cartridge  16 . 
     FIG. 23 illustrates one hose  204  extending from cylindrical sleeve  26  on print cartridge  16 . 
     As ink is being depleted from the ink bag  51  within each print cartridge  16  while printing, ink is drawn through flexible hoses  204  into their respective print cartridges  16 . Alternatively, refilling may occur at predetermined times, such as at the end of a printing cycle or at other times. 
     In another embodiment valve  24  is removed from print cartridge  16  and the end of hose  204  is provided with a simple male type tip which is inserted through the now empty hole through outer frame  30  and inner frame  54  to create a fluid seal. In another embodiment, the end of hose  204  is simply pushed over the end of valve  24 . 
     It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention.