Slingshot Printing LLC v. HP Inc.

Western District of Texas, txwd-6:2019-cv-00362

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2 US00793.8523B2 (12) United States Patent (10) Patent No.: US 7,938,523 B2 Aldrich (45) Date of Patent: May 10, 2011 (54) FLUID SUPPLY TANKVENTILATION FOR A 5,721.577 A * 2/1998 Ostermeier et al. ............ 347.86 MICRO-FLUIDEUECTION HEAD 5,801,737 A * 9/1998 Sato et al. ....................... 347.86 5,877,794. A * 3/1999 Takagi ............................ 347/87 (75) Inventor: Charles Stanley Aldrich, Nicholasville, 5,903,293 A * 5/1999 Nikkels et al. .................. 347.86 KY (US) 5,905,518 A * 5/1999 DeFilippis ...................... 347.85 5,953,030 A * 9/1999 Ishinaga et al. ................. 347.86 (73) Assignee: Lexmark International, Inc., g 2. f: 1 &9. Sys, al. ................ i. 4 -W CTZ C al. . . . . . . . . . . . . . . . . . . . . . . Lexington, KY (US) 6.254.226 B1* 7/2001 Lengyel et al. ................. 347.86 c -r 6,270,207 B1 * 8/2001 Sasaki ............................. 347.86 (*) Notice: Subsyster's 6,280,024 B1* 8/2001 Miyazawa et al. .............. 347.86 p 6,502,933 B2 * 1/2003 Lim et al. ........................ 347.86 U.S.C. 154(b) by 998 days. 6,550,900 B2 * 4/2003 Chan et al. ...................... 347.86 6,585,360 B1* 7/2003 Dietl ............................... 347.86 (21) Appl. No.: 11/762,101 6,880,921 B2 * 4/2005 Aponte et al. .................. 347.86 7,114,801 B2 * 10/2006 Hall et al. ....................... 347/92 (22) Filed: Jun. 13, 2007 7.255.431 B2* 8/2007 Lui ......... ... 347.86 O O 2008/O165214 A1* 7/2008 Yuen ................................. 347/7 (65) Prior Publication Data * cited by examiner US 2008/030974.0 A1 Dec. 18, 2008 (51) Int. Cl. Primary Examiner — Ryan Lepisto B4 2/9 (2006.01) B4 2/75 (2006.01) (52) U.S. Cl. ................ 347/92: 347/84; 347/85; 347/86; (57) ABSTRACT 347/89: 347/93 s An improved fluid supply tank for a micro-fluid ejection head (58) Field of Classification Search .................... .. and method for improving operation of a micro-fluid ejection See application file for complete search history. device. The fluid supply tank has a body portion for holding a fluid to be ejected. The body portion includes a fluid exit port (56) References Cited on an exit end thereof and a cover on an opposing end thereof. An internal vent conduit is disposed in the tank between the U.S. PATENT DOCUMENTS exit end and the cover for air removal adjacent to the exit port. 5,216,450 A * 6/1993 Koitabashi et al. ............. 347/87 5,504,511 A * 4/1996 Nakajima et al. ... ... 347/86 5,703,633 A * 12/1997 Gehrer et al. ................... 347/86 18 Claims, 8 Drawing Sheets 5 2 U.S. Patent May 10, 2011 Sheet 1 of 8 US 7,938,523 B2 ~-*. … · -· ~.-…:*< *~ .x~*çº~. 2 2 U.S. Patent May 10, 2011 Sheet 3 of 8 US 7,938,523 B2 .3% &*)& ¿?/&~ ?£!' Z,Ž 2 2 U.S. Patent May 10, 2011 Sheet 5 of 8 US 7,938,523 B2 2 U.S. Patent May 10, 2011 Sheet 6 of 8 US 7,938,523 B2 2 2 U.S. Patent May 10, 2011 Sheet 8 of 8 US 7,938,523 B2 Ys. N. 8-Sr. St. SS & $3. ''' & s' v. 2 US 7,938,523 B2 1. 2 FLUID SUPPLY TANK VENTILATION FORA pump system to remove air from the fluid storage tanks. MICRO-FLUIDEUECTION HEAD Accordingly, there is a need for a more cost effective device to remove air from fluid storage tanks for micro-fluid ejection FIELD OF THE DISCLOSURE devices. In view of the foregoing needs, one embodiment of the The present disclosure is generally directed toward micro disclosure provides a fluid Supply tank for a micro-fluid ejec fluid ejection heads and to fluid Supply components for ejec tion head. The fluid supply tank has a body portion for holding tion heads. In particular, the disclosure relates to structures a fluid to be ejected. The body portion includes a fluid exit for improving venting of fluid Supply tanks for micro-fluid port on an exit end thereof and a cover on an opposing end ejection heads. 10 thereof. An internal vent conduit is disposed in the tank between the exit end and the cover for air removal adjacent the BACKGROUND AND SUMMARY exit port. Another embodiment of the disclosure provides a method Micro-fluid ejection heads are useful for ejecting a variety for enhancing the operation of a micro-fluid ejection device. of fluids including inks, cooling fluids, pharmaceuticals, 15 The method includes, disposing an internal vent conduit in a lubricants and the like. A widely used micro-fluid ejection fluid supply container for the micro-fluid ejection device. The head is in an inkjet printer. As the fluid droplet size and speed vent conduit is disposed between a fluid exit end of the con of fluid ejection increases, factors that effect fluid ejection are tainer and a container cover opposite the fluid exit end. The magnified requiring solutions to problems that previously did fluid Supply container is installed on the micro-fluid ejection not exist. device so that any trapped air between the container and the Micro-fluid ejection devices, such as inkjet printers, with device is urged through the internal vent conduit through an replaceable fluid Supply tanks may have or develop a problem atmospheric vent in the cover. of trapping air adjacent to a connection between the fluid The exemplary embodiments disclosed herein may miti Supply tank and an ejection head structure. Trapped air may gate the above described problems by providing a vent pathin also be confined in an intermediate area between a fluid flow 25 an interior portion of the fluid supply tank between the cover path from the fluid Supply in a cartridge or tank and the and the fluid exit port of the fluid supply tank. The vent may ejection head structure. Expansion and/or contraction of the be effective for venting air adjacent the outlet port when the trapped air as the result of atmospheric pressure or altitude outlet port is sealed, in the case of a removable fluid supply changes may result in changes in pressure of the fluid at tank or may be effective to remove air from fluid supply paths noZZles in the ejection head. Such pressure changes or air 30 in an ejection head for a disposable fluid Supply tank and expansion may result in seepage of fluid from the nozzles ejection head. Removal of air is important to prevent when the nozzles are exposed to less than atmospheric pres unwanted or untimely loss of fluid from the fluid storage tank Sure or air intake into the nozzles when there is a negative as a result of atmospheric pressure changes that may expand pressure in the ejection head adjacent to the nozzles. or contract any air bubbles inside the tank. When the fluid supply container is removably attached to a 35 Exemplary embodiments may avoid having to configure permanent or semi-permanent ejection head structure, there ejection head tanks with large air collection Volumes or hav are additional concerns with regard to trapping air. Typically, ing to incorporate into the fluid ejection devices such as during the attachment or removal of a fluid Supply tank onto printers, air removal mechanisms or purge maintenance sta a permanent or semi-permanent micro-fluid ejection head, tions. Another advantage of the ventilation path may be that there may be an airspace or Volume of airin an exit port of the 40 the path allows fluid to be absorbed into the felts rather than fluid supply tank and/or flow features in the ejection head. A retained in the fluid exit port of the tank. Trapped air that change in air Volume may result from the displacements expands adjacent to the fluid exit port may be effectively encountered in the process of exchanging fluid Supply tanks removed using the ventilation path provided in the tank. and Such volume change may cause seepage of fluid from the ejection head nozzles or air ingestion at the nozzles. For 45 BRIEF DESCRIPTION OF THE DRAWINGS proper or prolonged operation of the ejection head, it is desir able to avoid both of these situations. Further advantages of exemplary embodiments disclosed In a multi-fluid Supply tank having ejection heads that eject herein may become apparent by reference to the detailed multiple different fluids, such as different colored inks, for description of the embodiments when considered in conjunc example, seepage of fluid from the nozzles may result in 50 tion with the drawings, which are not to scale, wherein like cross-contamination of fluids. Some fluid containers include reference characters designate like or similar elements a relatively large breathing mechanism (a spring loaded air throughout the several drawings as follows: bag within the tank, for example) and relatively large air FIG. 1 is a perspective view, not to scale, of a removable storage Volumes to retain and accommodate ingested air and fluid supply tank for a micro-fluid ejection device: Volume changes due to pressure changes. In other instances, 55 FIG. 2 is a perspective view, not to scale, of the removable a purging pump may be used to remove air through the fluid supply tank of FIG. 1 with a cover removed; noZZles of the ejection head. When a purging pump is used, FIG. 3 is a cross-sectional side view, not to scale, of a the ejection head is moved to a maintenance station where removable fluid Supply tank containing a vent conduit accord purging of air may occur. ing to an embodiment of the disclosure; The removal of air from the fluid storage tanks becomes 60 FIG. 4 is a top plan view, not to scale, of an inside of the even more critical as the size of the storage tanks is decreased fluid supply tank of FIG. 3; relative to an amount of fluid contained in the storage tank. In FIG. 5 is a perspective view, not to scale, of a removable larger fluid storage tanks, an excess Volume is available for fluid Supply tank attached to an ejection head structure reducing the effects of air Volume changes in the tank. How according to an embodiment of the disclosure. ever, Smaller tanks having the same Volume of fluid as larger 65 FIG. 6 is a cross-sectional side view, not to scale, of the tanks are less tolerant of air Volume changes. Also, it is not removable fluid supply tank and ejection head structure of desirable, from a cost point of view, to provide an air purging FIG. 5; 2 US 7,938,523 B2 3 4 FIG. 7 is a cross-sectional side view, not to scale, of a As used herein, the terms "foam and "felt will be under removable fluid Supply tank being attached to an ejection stood to refer generally to reticulated or open cell foams head structure; having interconnected Void spaces, i.e., porosity and perme FIG. 8 is an enlarged cross-sectional side view, not to scale, ability, of desired configuration which enable a fluid to be of the removable fluid supply tank removably attached to the retained within the foam or felt and to flow therethrough at a ejection head structure of FIG. 7: desired rate for delivery of fluid to the micro-fluid ejection FIG. 9 is a perspective view, not to scale, of a disposable head 30. Foams and felts of this type are typically polyether ejection head structure and fluid Supply tank according to polyurethane materials made by methods well known in the another embodiment of the disclosure; and art. A commercially available example of a suitable foam is a FIG. 10 is a cross-sectional side view, not to scale, of the 10 felted open cell foam which is a polyurethane material made disposable ejection head structure and fluid Supply tank of by the polymerization of a polyol and toluene diisocyanate. FIG. 9. The resulting foam is a compressed, reticulated flexible poly ester foam made by compressing a foam with both pressure DESCRIPTION OF THE EXEMPLARY and heat to specified thickness. EMBODIMENTS 15 Fluid in the pores of the capillary section 32 may be replen ished from the liquid section 34 through a path 37 in a parti tion wall 39 between the capillary section 32 and the liquid With reference to FIG. 1, there is illustrated an exemplary section34. In one embodiment, two different densities of felt removable fluid supply tank 10 having a body portion 12 and pads 36 and 38 are used to provide fluid retention and con a cover 14. The cover 14 includes a fluid fill port 16 and a trolled feeding of fluid to the ejection head 30. For example, serpentine air removal vent path 18. Interior views of the tank the tank 10 may include a low density felt 36 and a medium 10 are illustrated in FIGS. 2, 3 and 4. As shown, the tank 10 density felt 38. The felts 36 and 38 hold the fluid and maintain includes side walls 12A and 12B, end walls 20A and 20Band a back pressure on the flow of fluid to the ejection head. a fluid outlet wall 22. In an exemplary embodiment of the Each time a removable fluid supply tank 10 is attached to an disclosure, one or both of the walls 12A and 12B may contain 25 ejection head structure 28, a volume of air in the exit port 26 an internal vent conduit 24 disposed between the fluid outlet and air volume displacement in the tank 10 or ejection head wall 22 and the cover 14 (FIG. 1). As described in more detail 30 is not assured of having a ventilation path to an atmosphere below, the vent conduit 24 enables air adjacent the fluid outlet external to the tank 10. In a conventional fluid supply tank, wall 22 or in an exit port 26 to flow to the cover 14 for exit ventilation is not assured because typically the felts 36 and 38 through the serpentine vent path 18. The vent conduit 24 may 30 substantially fill the capillary section 32 of the tank 10. How prevent entrapment of air or fluid in the tank's exit port 26. ever, according to an embodiment of the disclosure, changes The fluid supply tank 10 and the cover 14 may be made of in fluid volume or air volume within the tank 10 may travel a variety of materials including metals and plastics that are through the vent conduit 24 to the atmosphere external to the resistant to fluids contained in the tank 10. For example, the tank 10. body 10 may be made of a polymeric material. Such as amor 35 More detail of the ejection head structure 28 is illustrated in phous thermoplastic polyethermide materials available from FIG. 7. According to one exemplary embodiment of the dis G. E. Plastics of Huntersville, N.C. under the trade name closure, the tank 10 is removable attached to the structure 28 ULTEM 1010, glass filled thermoplastic polyethylene tereph so that the exit port 26 is fluidly connected to a wick 40 for thalate resin materials available from E. I. du Pont de Nem flow of fluid from the tank 10 to a filtered fluid reservoir 42 ours and Company of Wilmington, Del. under the trade name 40 adjacent to the ejection head 30. A gasket 44 is provided at a RYNITE, syndiotactic polystyrene containing glass fiber connection between the tank 10 and the wick 40 to provide a available from Dow Chemical Company of Midland, Mich. fluid seal between the tank 10 and wick 40 so that fluid does under the trade name QUESTRA, polyphenylene ether/poly not leak out of the tank 10 and air is not ingested through the styrene alloy resin available from G. E. Plastics under the wick 40 or into the tank 20. Also, the gasket 44 reduces trade names NORYL SI1 and NORYL 300X and polyamide/ 45 exposure of the fluid in the tank 10 to the atmosphere external polyphenylene ether alloy resin available from G. E. Plastics to the tank which may lead to unwanted evaporation of fluid under the trade name NORYL GTX. A particularly suitable in the tank 10. The serpentine vent path 18 on the cover 14 material for making the body 10 is ULTEM 1010 polymer. provides a vented airpath out of the capillary section32 of the A micro-fluid ejection device Such as an inkjet printer may tank 10 without resulting in excessive evaporative loss offluid contain one or more of the removable fluid supply tanks 10. 50 from the tank 10. As shown in FIG. 5, each of the removable fluid supply tanks FIG. 8 is an enlarged view of the connection between the 10 may be attached to an ejection head structure 28 that exit port 26 of the tank 10 and the wick 40. Upon attaching the includes one or more micro-fluid ejection heads 30 (FIG. 6). tank 10 to the wick 40, a depression or air gap 48 may be Across-sectional view of the tank 10 is illustrated in FIGS. formed between the outlet wall 22 of the tank and the felt pad 6 and 7. The tank 10 may include a fluid capillary section 32 55 38. Such gap 48 may extend over an entire width of the tank and a liquid section 34. The fluid capillary section 32 may 10 so that it intersects the vent conduit 24 on side wall 12A of contain one or more felt pads 36 and 38, such as felted foam the tank 10. Accordingly, there will be air flow communica or other porous absorption members for controllably feeding tion between the outlet port 26, the gap 48 and the vent fluid to the ejection head 30 and for providing negative pres conduit 24. sure in the tank 10 to prevent unwanted or unintended flow of 60 The vent conduit 24 has a size and/or construction that are fluid from the ejection head 30. For the purposes of this effective for removing air from the exit port 26 area or the disclosure, a wide variety of negative pressure producing ejection head 30 without substantially filling with fluid. For materials may be used to provide controlled fluid flow from example, the vent conduit 24 may have a width (W) ranging the tank 10 to the micro-fluid ejection head 30. Such negative from about 0.5 to about 2 millimeters and a depth (D) ranging pressure inducing materials may include, but are not limited 65 from about 0.5 to about 2 millimeters as shown in FIG. 4. The to, open cell foams, felts, capillary containing materials, dimensions of the vent conduit 24 only need to be large absorbent materials, and the like. enough to provide an air path around the felts 36 and 38 or 2 US 7,938,523 B2 5 6 between the felts 36 and 38 and side wall 12A. Accordingly, 2. The fluid supply tank of claim 1, wherein the internal the vent conduit 24 need only be large enough to provide a vent conduit comprises a channel disposed in an interior side path for air from the exit port 26 and air space adjacent the wall of the fluid supply tank. bottom wall 22 past the felts 36 and 38 to the serpentine vent 3. The fluid supply tank of claim 1, wherein the cover 18 on the cover 14. The vent conduit 24 may have a variety of 5 comprises a serpentine vent structure and the internal vent cross-sectional shapes including rectangular, triangular, conduit is in airflow communication with the serpentine vent semi-circular, and the like. Also, the vent conduit 24 may be Structure. other than a linear path from the bottom wall 22 to the cover vent 4. The fluid supply tank of claim 1, wherein the internal 14 and may be provided by an open channel as shown or by and the conduit comprises tubing disposed between the cover tubing disposed in the tank 10 adjacent the side wall 12A and 10 5. Theexit fluid end of the fluid supply tank. supply tank of claim 1, wherein the fluid supply in a channel in the bottom wall 22 connecting the channel in tank is removably attached to an ejection head structure. the side wall 12A with the exit port 26 as shown in FIG. 4. 6. The fluid supply tank of claim 1, wherein the internal The surface tension of fluid in the tank is a consideration for the dimensions of the width and depth of the vent conduit vent conduit comprises a conduit having cross-sectional dimensions that provide a non-fluid wettable vent channel. 24. Fluids having a surface tension similar to the Surface 15 7. The fluid supply tank of claim 1, wherein the internal tension of water may have vent conduit 24 dimensions having vent conduit comprises a conduit having a width ranging from a width (W) of about 1 millimeter and a depth (D) of about 1 millimeter in order to reduce or eliminate wetting of the about 0.5 to about 2 millimeters. and a depth ranging from about 0.5 to about 2 millimeters conduit 24 with the fluid. In an alternative embodiment, the 8. The fluid supply tank of claim 1, wherein the internal conduit 24 may be made of or coated with a hydrophobic vent conduit comprises a conduit coated with a hydrophobic coating material Such as polytetrafluoroethylene or polypro coating. pylene or polyethylene for aqueous fluids in the tank 10 or 9. The fluid supply tank of claim 1, wherein the internal may be coated with a hydrophilic coating material Such as vent polyester or polyamide for non-aqueous fluids in the tank 10. rial. conduit comprises tubing made of a hydrophobic mate FIGS. 9 and 10 illustrate an alternative embodiment of the 25 disclosure wherein a vent conduit 50 is used with a disposable ejection 10. A method for enhancing the operation of a micro-fluid ejection head and fluid supply tank 52. In this embodiment, an device, comprising: ejection head 54 is fixedly attached to a body 56 containing a disposing an internal vent conduit in a fluid Supply con fluid to be ejected. As with the previous embodiment, the tainer for the micro-fluid ejection device, wherein the body 56 may include fluid retention capillary members 58 30 vent conduit is disposed in air flow communication and 60 and a liquid supply section 62 for replenishing the fluid between an air space of a fluid exit end of the container in the capillary members 58 and 60. In this embodiment, the and a container cover opposite the fluid exit end, the vent conduit 50 is disposed adjacent a side wall of the body 56 container cover having an opening in fluid communica between an air chamber 63 in the ejection head 54 and a cover tion with atmosphere; and 66 containing a serpentine air outlet vent 68 as generally 35 installing ejection the fluid Supply container on the micro-fluid device so that any trapped air between the con described above. Fluid from the capillary member 60 flows tainer and the device is urged to said atmosphere through through a wick or filter 65 into a filtered fluid chamber 64 for the internal vent conduit through an atmospheric vent in feed to the ejection head 54. In all other respects, the vent the cover. conduit 50 may have physical dimensions and characteristics 11. The method of claim 10, wherein the internal vent similar to the vent conduit 24 described above. 40 It is contemplated, and will be apparent to those skilled in conduit of the comprises a channel disposed in an interior side wall fluid supply container. the art from the preceding description and the accompanying drawings that modifications and/or changes may be made in in 12. The method of claim 10, wherein the atmospheric vent the cover comprises a serpentine vent structure and the the embodiments, disclosed herein. Accordingly, it is internal vent conduit is in air flow communication with the expressly intended that the foregoing description and the 45 serpentine vent structure. accompanying drawings are illustrative of exemplary 13. The method of claim 10, wherein the internal vent embodiments only, not limiting thereto, and that the true spirit conduit and scope of the disclosed embodiments be determined by fluid exitcomprises tubing disposed between the cover and the end of the container. reference to the appended claims. 14. The method of claim 10, wherein the fluid supply 50 What is claimed is: container is removably attached to an ejection head structure 1. A fluid supply tank for a micro-fluid ejection head, the for15. the micro-fluid ejection device. The method of claim 10, wherein the internal vent fluid Supply tank comprising: a body portion for holding a fluid to be ejected, the body sions thatcomprises conduit a conduit having cross-sectional dimen portion having a fluid exit port on an exit end thereof and 55 16. Theprovide a non-fluid wettable vent channel. method of claim 10, wherein the internal vent a cover on an opposing end thereof of the body portion, the cover having an opening in fluid communication conduit comprises a conduit having a width ranging from about 0.5 to about 2 millimeters and a depth ranging from with atmosphere; about 0.5 to about 2 millimeters. an internal vent conduit disposed between the exit end and 17. The method of claim 10, wherein the internal vent the cover for removing air adjacent to the fluid exit port conduit 60 and releasing the air through the cover to said atmo ing. comprises a conduit coated with a hydrophobic coat sphere; and 18. The method of claim 10, wherein the internal vent an air space in the fluid exit port wherein the internal vent conduit comprises tubing made of a hydrophobic material. conduit is in air flow communication with the air space and the cover. k k k k k