Patent Abstract:
A refill junction for a fluid container including an exterior surface; a retaining clip having an outer face and an inner face, at least one of the exterior surface and the inner face including at least one capillary.

Full Description:
BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   This invention relates to capturing fluid spilled during refill of a fluid ejection head. 
   2. Description of Related Art 
   Fluid ejector systems, such as drop-on-demand liquid ink printers, have at least one fluid ejector from which droplets of fluid are ejected towards a receiving sheet. For example, scanning inkjet printers are equipped with printheads containing fluid ink. The fluid is applied to a sheet in an arrangement based on print data received from a computer, a scanner or similar device. To control the delivery of the fluid to the sheet, fluid ejection heads are moved across the sheet to provide the fluid to the sheet, which is ejected as drops. Each drop corresponds to a liquid volume designated as a pixel. Each pixel is related to a quantity needed to darken or cover a particular unit area. 
   In order to lower cost and improve performance by limiting inertia, moving-head fluid ejection systems are designed with low-weight fluid ejection heads. In order to minimize weight, the fluid ejection heads contain a relatively small quantity of fluid. Consequently, the fluid injection heads (or their fluid reservoirs) must either be periodically replaced or refilled. Refillable cartridges are commonly used in home-use printers. Some heavier-use printers in industry attach the fluid ejector via an umbilical tube to a larger tank for continuous refilling. Other heavier-use printers periodically refill the fluid ejection head. 
   Replacing cartridges requires frequent interaction by the user, and is considered disadvantageous for fluid ejectors used in volume production or connected by a network to the ejection data source. Umbilical systems can be expensive, requiring pressurization, tubing, tube harness dressing, and can suffer performance degradation from moisture loss, pressure fluctuations due to acceleration or temperature variation, and motion hysterisis from tubing harness drag. 
   Periodic refill systems also require interaction by the user. Using a periodic refill system requires one or more refill ports. These ports tend to leak when they are engaged or disengaged. This can result in contamination the fluid ejection medium or even result in fluid coming into contact with the user. 
   Accordingly, containers for consumable fluids in various applications of fluid ejection may require capturing the leaked fluid. Such applications include, but are not limited to, ink-jet printers, fuel cells, dispensing medication, pharmaceuticals, photo results and the like onto a receiving medium, injecting reducing agents into engine exhaust to control emissions, draining condensation during refrigeration, etc. 
   SUMMARY OF THE INVENTION 
   This invention provides systems, methods and structures for capturing fluid spilled when a fluid refill operation is performed on a fluid ejector. 
   This invention provides systems, methods and structure for storing spilled fluid that has been captured during a fluid refill operation. 
   This invention provides systems, methods and structure for disposing of spilled fluid that has been captured and stored during a fluid refill operation. 
   This invention provides systems, methods and structure for preventing the spilling of fluid during a fluid refill operation. 
   In various exemplary embodiments, a refill system for a fluid reservoir includes a venting port and a fluid inlet port located at a fluid ejection head refill junction. The fluid ejection head refill junction is typically covered by a retaining clip. Typically the top port is the venting port and the bottom port is the fluid inlet port. Fluid is either pushed into the bottom port under pressure or a vacuum is applied to the top port to draw the fluid in through the bottom port. The fluid is introduced through a needle or tubing which engages the port. In various exemplary embodiments, capturing spilled fluid includes providing capillaries in the regions where spilled fluid accumulates. The spilled fluid is transported away from a face of the retaining clip to a reservoir. 
   In various exemplary embodiments, the fluid is held in the reservoir by a fluid absorbing medium so that it is retained until it can be disposed of. 
   In various exemplary embodiments, the reservoir is provided with vents which open on the face of the retaining clip to promote evaporation of the fluid. Evaporation of the fluid is further promoted by the motion of the fluid reservoir resulting in the passage of air across the vents. 
   In various exemplary embodiments, the fluid inlet port and venting port are sealed by a ball valve seal to prevent fluid from spilling. 
   These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various exemplary embodiments of the devices, systems and methods of this invention will be described in detail with reference to the following figures, wherein: 
       FIG. 1  is an isometric view of an exemplary embodiment of a fluid refill system usable with the systems, methods and structures of the invention; 
       FIG. 2  is a view of an exemplary embodiment of a fluid ejection head having a refillable fluid reservoir; 
       FIG. 3  is a rear view of a retaining clip according to an exemplary embodiment of this invention; and 
       FIG. 4  is a section view of a fluid refill junction according to an exemplary embodiment of this invention. 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   The following detailed description of various exemplary embodiments of the fluid ejection systems according to this invention may refer to one specific type of fluid ejection system, e.g., an inkjet printer, for sake of clarity and familiarity. However, it should be appreciated that the principles of this invention, as outlined and/or discussed below, can be equally applied to any know or later-developed fluid ejection systems, beyond the fluid jet printer specifically discussed herein. 
   A fluid ejector  100 , such as, for example, an inkjet printhead, is produced, distributed and/or installed with a fluid reservoir, such as, for example, an ink reservoir, typically filled with a fluid, such as, for example, ink. The fluid ejector, includes, in accordance with this invention, a retaining clip  111  which is secured in place on a portion of the reservoir  110  to cover the fluid refill junction  102 . The retaining clip  111  is described in detailed below. 
     FIG. 1  shows a fluid ejection head  100  usable with a fluid refill system according to the systems, methods and structures of this invention. As shown in  FIG. 1 , the fluid ejection head  100  includes the refillable fluid container or reservoir  110  with refill junction  102 . The fluid reservoir  110  of the fluid ejection head  100  can be connected to a refill station  150  when a detector  160  detects, for example, that the fluid level in the fluid reservoir  110  has fallen below a predetermined level. Subsequently, the fluid reservoir  110  of the fluid ejection head  100  can be disconnected from the refill station  150  when the detector detects that the level in the fluid reservoir  110  has risen to, for example, a position above the predetermined level. 
   As shown in  FIG. 2 , in various exemplary embodiments, the retaining clip  111  serves to cover the refill junction  102  between the reservoir  110  and the refill station  150 .  FIG. 2  shows the front face  113  of the retaining clip. An air inlet port and an ink inlet port are collectively shown as refill ports  114 . Each refill port  114  has a respective injection tube or needle on refill station  150  and is aligned thereto. 
   When the reservoir  110  is low on fluid, the printhead  100  is transported to the refill station  150 . The refill ports  114  are then positioned to be aligned with the refill station needles or tubing and are engaged thereto. Each refill port  114  is provided with a valve which is normally closed to provide a seal. When the refill station needles or tubes engage the refill ports, the valves are opened. In various exemplary embodiments, one of the needles or tubes applies a pressure less than atmospheric, decreasing the pressure within the reservoir  110  and draining fluid from the second needle or tube that is connected to the fluid supply. In other exemplary embodiments, one of the needles or tubes is connected to a pressurized source of fluid which fills the reservoir  110  through one refill port while the second refill port is vented to atmospheric pressure. 
   During this process, fluid may pool on the outside surfaces of the printhead resulting in staining, poor print quality and user contamination. 
     FIG. 3  is a rear view of a retaining clip  111  according to an exemplary embodiment of the invention. As shown in  FIG. 3 , retaining clip  111  includes clips  119  to secure the retaining clip onto printhead  100 . Although clips  119  are shown, any suitable known or later-developed systems, methods or structure may be used to secure retaining clip  111  to printhead  100 . 
   Retaining clip  119  also includes rear wall  132 . Rear wall  132  has through holes which include alignment holes  130  which are used to align retaining clip  119  when securing it to printhead  100 . It should be appreciated that any suitable known or later-developed systems, methods or structure for alignment may be substituted for alignment holes  130 . Through holes  131  are also provided for refill ports  114 . 
   Selected portions of rear wall  132  have raised capillary ribs  112 . The ribs  112  are located so as to direct spilled fluid away from alignment holes  130  and through holes  131 , keeping the fluid away from the face of retaining clip  111 . The fluid is then directed via gravity to the bottom portion of retaining clip  111  where it is absorbed by fluid waste pad  116  (see  FIG. 4 ). Fluid waste pad  116  is located in reservoir  109  formed in retaining clip  111 . 
   Retaining clip  111  is also provided with evaporative slits  118  according to one exemplary embodiment. Evaporative slits  118  are located at the lower portion of retaining clip  111  in proximity to fluid waste pad  116  to promote evaporation of the fluid. 
   According to an exemplary embodiment of the invention, the evaporative slits are located perpendicular to the path of travel of the printhead. When the printhead is in operation, air traveling through evaporative slits  118  further promotes evaporation. 
   According to other exemplary embodiments of the invention, rear wall  132  may be provided with raised lips  133  which surround or partially surround the alignment holes  130  and refill ports  114 . According to one exemplary embodiment, raised lips  133  completely surround alignment holes  130 , so fluid runs around alignment holes  130  before running down due to gravity. This further reduces leakage and increases fluid capture. 
   According to another exemplary embodiment, raised lips  133  partially surround refill port  114 , so that fluid runs partially around refill port  114  and then runs down to areas containing capillary ribs  112 . 
   In other exemplary embodiments of the invention, capillary ribs  114  may be replaced with capillary channels. 
     FIG. 4  shows a section view of a fluid refill junction  102  and fluid refill ports  114 . According to an exemplary embodiment of the invention, a ball valve seal  120  is provided at the junction of refill station  150  and reservoir  110 . The ball valve seal  120  includes a ball  122  biased by spring  124  to be in contact with seal  126 . In one exemplary embodiment, seal  126  is a compliant seal. In other exemplary embodiments, seal  126  can be a septum type seal which is pierced by a needle or has a hole in it to receive a needle or tube from refill station  130  or a combination of a septum type seal with a hole. 
   When the reservoir is to be refilled, the needle or tube engages the ball  122  to overcome the bias of the spring  124  and separates the ball  122  from the seal  126  to create a passage for fluid or air from the refill station to or from the reservoir  110 . When the needle or tube is removed from refill port  114 , the ball  122  is again biased by the spring  124  to come into contact with seal  126  to reduce or prevent fluid or air from escaping into or out of the reservoir  110 . 
   Refill junction  102  includes a face  115  which is covered by retaining clip  111 . In various exemplary embodiments, the face  115  may include capillary ribs  115  which provide the same function as capillary ribs  112 . 
   While this invention has been described in conjunction with exemplary embodiments outlined above, many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes can be made without departing from the spirit and scope of the invention.

Technology Classification (CPC): 1