Inkjet printer with off-axis ink supply

• US 6,033,064 A
• Filed: 08/30/1996
• Issued: 03/07/2000
• Est. Priority Date: 10/31/1994
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Barinaga, John A., Cameron, James M., Hauck, Mark, Underwood, John A., Pawlowski, Norman E. Jr., Seccombe, S. Dana
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Nguyen, Judy
• Application Number:
  US08/706,062
• Time in Patent Office: 1,285 Days
• Field of Search: 347/85, 347/86, 347/87
• US Class Current: 347/87
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17506 Refilling of the cartridge
• CPC Class Codes: B41J 2/17509 Whilst mounted in the printer
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/1752 Mounting within the printer
• CPC Class Codes: B41J 2/17523 Ink connection
• CPC Class Codes: B41J 2/17533 Storage or packaging of ink cartridges
• CPC Class Codes: B41J 2/17543 Cartridge presence detection or type identification
• CPC Class Codes: B41J 2/1755 mechanically
• CPC Class Codes: B41J 2/17553 Outer structure
• CPC Class Codes: B41J 2/17556 Means for regulating the pressure in the cartridge
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/17516 comprising a collapsible ink holder, e.g. a flexible bag
• CPC Class Codes: B41J 2002/17569 based on the amount printed or to be printed
• CPC Class Codes: B41J 2002/17573 using optical means for ink level indication
• CPC Class Codes: B41J 2002/17576 using a floater for ink level indication
• CPC Class Codes: G01F 23/003 with a probe suspended by rotatable arms with floats G01F23/32
• CPC Class Codes: G01F 23/205 for discrete levels
• CPC Class Codes: G01F 23/72 : using magnetically actuated indicating means

Abstract

In the preferred embodiment, an inkjet printer includes a replaceable print cartridge which is inserted into a scanning carriage. An ink tube extends from the scanning carriage to a separate ink supply located within the printer. A fluid interconnect on the print cartridge connects to a fluid interconnect on the carriage when the print cartridge is inserted into the carriage to complete the fluid connection between the external ink supply and the print cartridge. In one embodiment, the fluid interconnection is made between the print cartridge and the ink tube simply by placing the print cartridge into a stall in the scanning carriage. A pressure regulator, which may be internal or external to the print cartridge, regulates the flow of ink from the external ink supply to the print cartridge. The external ink supply may be pressurized or non-pressurized.

Claims

1. A printing system comprising:

a print cartridge having a printhead for receiving electrical signals and, in response, for ejecting droplets of ink, a first ink reservoir in fluid communication with said printhead, and a body housing said first ink reservoir and said printhead said body having an ink entrance port including a first interconnect member in fluid communication with said first ink reservoir;

a pressure regulator, internal to said print cartridge, for controlling a flow of ink into said ink entrance port;

a carriage for receiving said print cartridge and having a second interconnect member, said second interconnect member making a fluid connection to said first interconnect member when said print cartridge is installed in said carriage; and

an ink source external to said print cartridge, said ink source comprising;

an ink supply station for containing at least one replaceable ink supply cartridge, said ink supply station having a third interconnect member in fluid communication with said second interconnect member on said carriage;

a replaceable ink supply cartridge having a second ink reservoir and a fourth interconnect member, said fourth interconnect member in fluid communication with said second ink reservoir and forming a fluid connection to said third interconnect member when said ink supply cartridge is installed in said ink supply station; and

a flexible ink conduit connected to said third interconnect member of said ink supply station and to said second interconnect member of said carriage.

2. The system of claim 1 wherein a pressure within said first ink reservoir is substantially unaffected by a height of said ink source relative to said print cartridge.

3. The system of claim 1 wherein said regulator includes a valve, said valve adjusting a flow of ink into said first ink reservoir based on a pressure differential between ambient pressure and pressure internal to said first ink reservoir.

4. The system of claim 1 wherein said flexible ink conduit comprises at least one tube containing Polyvinylidene Chloride.

5. The system of claim 1 wherein said ink source includes ink at a pressure greater than ambient pressure.

6. The system of claim 5 wherein said ink supply cartridge includes a spring force disposed between said second ink reservoir and a wall of said ink supply cartridge such that ink in said ink source is constantly under pressure.

7. The system of claim 4 wherein said at least one tube containing Polyvinylidene Chloride is coated with a layer of Polyvinylidene Chloride.

8. The system of claim 6 wherein said spring force is provided by a mechanical spring.

9. The system of claim 1 wherein said ink source includes a pump having a pump chamber in fluid communication with said second ink reservoir, said pump intermittently subjecting said ink within said pump chamber to pressure above said ambient pressure and, at other times, at approximately ambient pressure.

10. The system of claim 1 wherein said fourth interconnect member comprises a spring, a stopper and a septum having a central hole, said spring urging said stopper against said central hole in said septum when said ink supply cartridge is not installed in said ink supply station to form an additional seal of said hole to prevent ink leakage from said hole.

11. The system of claim 1 wherein said fourth interconnect member comprises a resilient septum having a self-sealing central hole.

12. The system of claim 1 wherein said fourth interconnect member comprises a poppet valve.

13. The system of claim 10 wherein said stopper is a ball, and said spring is a spiral spring, said spiral spring urging said ball against said hole when said ink supply cartridge is not installed in said ink supply station.

14. A printing system comprising:

an ink supply station for containing a supply of ink, said ink supply station having a first interconnect member;

a replaceable ink supply cartridge for installation in said ink supply station, said ink supply cartridge having a first ink reservoir and a second interconnect member, said second interconnect member being in fluid communication with said first ink reservoir and forming a fluid connection to said first interconnect member when said ink supply cartridge is installed in said ink supply station;

a scanning carriage having a flexible ink conduit connected to said first interconnect member of said ink supply station, said carriage having a third interconnect member in fluid communication with said ink conduit; and

a print cartridge for installation in said carriage, said print cartridge having a fourth interconnect member in fluid communication with a second ink reservoir internal to said print cartridge, said fourth interconnect member being connectable to said third interconnect member on said carriage to enable ink to flow from said ink supply station, through said ink conduit, and into said second ink reservoir, said print cartridge containing a pressure regulator comprising;

a valve coupled to said second ink reservoir and controlling an opening in an ink path between said second ink reservoir and said fourth interconnect member;

an expandable member with a reference surface and a reservoir surface, said reference surface in fluid communication with the outside atmosphere and said reservoir surface in fluid communication with said second ink reservoir; and

an actuator in contact with said expandable member for actuating said valve based upon expansion or contraction of said expandable member due to a differential pressure between the outside atmosphere and said second ink reservoir, said valve controlling a flow of ink into said second ink reservoir such that ink is supplied to a printhead within said print cartridge at a substantially constant gauge pressure.

21. The system of claim 14 wherein said valve comprises a valve seat and a nozzle, said valve seat and nozzle having an area of mutual contact, wherein said nozzle is tapered to reduce said area of contact between said nozzle and said valve seat, thereby increasing a valve sealing pressure.

22. The system of claim 14 wherein said actuator comprises a lever pivotally mounted to said pressure regulator for rotation about an axis, said valve comprises a valve seat and a nozzle, and wherein said valve seat is mounted on said lever.

15. A printing system comprising:

a print cartridge having a printhead for receiving electrical signals and, in response, for ejecting droplets of ink, a first ink reservoir in fluid communication with said printhead, and a body housing said first ink reservoir and said printhead, said body having an ink entrance port including a first interconnect member in fluid communication with said first ink reservoir;

a pressure regulator, internal to said print cartridge, for controlling a flow of ink into said ink entrance port;

a carriage for receiving said print cartridge and having a second interconnect member, said second interconnect member making a fluid connection to said first interconnect member when said print cartridge is installed in said carriage; and

an ink source external to said print cartridge comprising;

a docking bay having a fluid inlet and a docked position;

a tube coupled to said fluid inlet and to said second interconnect member; and

a replaceable ink supply for removable insertion into said docked position within said docking bay, said ink supply comprising;

a chassis;

a second ink reservoir coupled to said chassis for containing a quantity of ink; and

a fluid outlet carried on said chassis for engaging said fluid inlet when said ink supply is in said docked position.

16. The system of claim 15 wherein said fluid outlet includes a spring, a stopper and a septum having a central hole, said spring urging said stopper against said central hole to prevent the flow of ink through said fluid outlet when said ink supply is not in said docked position said fluid inlet displacing said stopper from said central hole when said ink supply is in said docked position to allow a flow of ink through said fluid outlet and into said fluid inlet.

17. The system of claim 15 wherein said docking bay comprises a pump actuator, and said ink supply further comprises a pump carried on said chassis in fluid communication with said second ink reservoir and said fluid outlet, said pump actuator actuating said pump when said ink supply is in said docked position to draw ink from said second ink reservoir and supply said ink through said fluid outlet to said tube.

18. The system of claim 17 further comprising a valve interposed between said pump and said second ink reservoir, said valve allowing a flow of ink from said second ink reservoir into said pump and limiting a flow of ink from said pump into said second ink reservoir.

19. The system of claim 17 in which said pump comprises a variable volume chamber.

20. The system of claim 19 in which said variable volume chamber has an expanded position and a retracted position, said chamber being internally biased toward said expanded position, said actuator overcoming the internal biasing of said chamber and urging said chamber toward said retracted position to pressurize ink within said chamber and urge ink from said pump through said fluid outlet and into said fluid inlet.

23. An ink delivery system supported on a rigid frame, on which a print cartridge mounted on a carriage moves relative to media in a print zone to deposit ink on said media, said print cartridge having a printhead for receiving electrical signals and in response, for ejecting droplets of ink, an ink chamber in fluid communication with said printhead, and a body housing said ink chamber and said printhead, said body having an ink inlet port in fluid communication with said ink chamber, said body also housing a pressure regulator, internal to said print cartridge for controlling a flow of ink into said ink inlet port, said carriage for receiving said print cartridge, said frame also supporting an off-carriage fixed supply station having a first interconnect member fluidically connected to said print cartridge ink inlet port via at least a flexible conduit, said system comprising:

a replaceable ink supply cartridge removably mounted on said fixed supply station and containing an ink reservoir, said ink supply cartridge having a second interconnect member in fluid communication with said ink reservoir and forming a fluid communication with said first interconnect member when said ink supply cartridge is removably mounted on said fixed supply station;

ink contained in said reservoir which passes out of said first interconnect member and said second interconnect member, through said conduit, and to said pressure regulator in said body of said print cartridge with a regulator setpoint between 0 and -25 inches of water, said reservoir and said regulator operatively coupled so that a reservoir ink pressure is maintained at a pressure above -10 inches of water and a relative height of said reservoir and a relative height of said pressure regulator are adjusted such that said pressure regulator setpoint controls an ink pressure at said printhead when the ink supply cartridge is removably mounted on the fixed supply station.

24. The system of claim 23 wherein said second interconnect member comprises a spring-loaded sealing member.

25. The system of claim 23 wherein a portion of ink within said reservoir is above ambient pressure.

26. The system of claim 23 wherein said fixed supply station includes a pump having a pump chamber in fluid communication with said ink reservoir, said pump intermittently subjecting said ink in said pump chamber to pressure above ambient pressure.

27. The system of claim 23 wherein said second interconnect member comprises a septum.

28. The system of claim 27 wherein said second interconnect member further comprises a spring-loaded sealing member.

29. A method of using a printing system comprising the steps of:

inserting a replaceable ink cartridge into an ink supply station in an inkjet printer;

providing a print cartridge in said printer, said print cartridge having a printhead for receiving electrical signals and, in response, for ejecting droplets of ink, an ink chamber in fluid communication with said printhead, and a body housing said ink chamber and said printhead, said body having an ink inlet port including a first interconnect member in fluid communication with said ink chamber, said body also housing a pressure regulator, internal to said print cartridge, for controlling a flow of ink into said ink inlet port;

supplying ink from said ink cartridge to a flexible tube connected to a second fluid interconnect member mounted on a carriage;

channeling said ink through said ink inlet port of said print cartridge in fluid communication with said second fluid interconnect; and

controlling a flow of ink into said chamber within said print cartridge using said pressure regulator internal to said print cartridge.

30. The method of claim 29 wherein controlling said flow of ink includes providing said pressure regulator with:

a valve for controlling an opening in an ink path leading to said chamber;

an expandable member with a reference surface and a chamber surface, said reference surface in communication with the outside atmosphere, and said chamber surface in fluid communication with ink within said chamber; and

an actuator in contact with said expandable member for actuating said valve based upon expansion and contraction of said expandable member due to a differential pressure between the outside atmosphere and said chamber, said valve controlling a flow of ink into said chamber such that ink is supplied to a printhead within said print cartridge at a substantially constant pressure.

31. The method of claim 30 wherein providing said pressure regulator includes providing said actuator with a lever pivotally mounted to said pressure regulator for rotation about an axis, providing said valve with a valve seat and a nozzle, said valve seat mounted on said lever.