Ink delivery system for high speed printing

• US 6,183,078 B1
• Filed: 10/31/1997
• Issued: 02/06/2001
• Est. Priority Date: 02/28/1996
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Pietrzyk, Joe R., Goldis, Yale, Courian, Kenneth J., Pawlowski, Norman E. Jr.
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): JACKSON, JUANITA DIONNE
• Application Number:
  US08/962,031
• Time in Patent Office: 1,194 Days
• Field of Search: 347/92, 347/85, 347/84, 347/86, 347/63, 347/65, 347/17, 347/18, 347/37, 347/40, 347/44
• US Class Current: 347/92
• CPC Class Codes: B41J 2/1404 Geometrical characteristics
• CPC Class Codes: B41J 2/14072 Electrical connections, e.g. details on electrodes, connecting the chip to the outside...
• CPC Class Codes: B41J 2/1408 Structure dealing with thermal variations, e.g. cooling device, thermal coefficients of materials
• CPC Class Codes: B41J 2/14145 Structure of the manifold
• CPC Class Codes: B41J 2/17509 Whilst mounted in the printer
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17526 Electrical contacts to the cartridge
• 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 2002/14387 Front shooter
• CPC Class Codes: B41J 2202/07 dealing with air bubbles

Abstract

Disclosed is an ink delivery system for high throughput commercial inkjet printing devices. The ink delivery system includes a high speed ink ejection printhead with a large number of nozzles and an ink flow design which provides for improved printhead cooling. The printhead design achieves high ink ejection rates by having a very short inlet channel length which is made possible by having nozzles with a constant distance from the edge of the printhead. In order to accommodate this constant distance from the edge of the printhead the entire array of nozzles is disposed at a angle relative to the direction normal to the scan direction. An impinging ink flow against the back of the printhead is provided to limit the temperature of the printhead. A bubble collection chamber to increase the life of the printhead and a pressure regulator to provide ink at a controlled pressure to the printhead may also be provided. Pressurized ink may be provided so that ink pressure may be properly controlled even during peak usage.

Claims

1. An inkjet printing device comprising:

a scanning carriage having a scan direction; and

a print cartridge mounted on the scanning carriage, the print cartridge comprising;

a housing having an internal ink chamber in fluid communication with an internal ink conduit;

a substrate having a plurality of outer edges, a front surface and a back surface, said substrate being mounted on said housing and including a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, said ink ejection chambers forming a straight linear array substantially along a length of the substrate, each ink ejection chamber having an ink inlet channel of a same length, said back surface having a portion across which ink flows;

an ink channel fluidically connecting said internal ink conduit with said ink inlet channels; and

a plurality of ink orifices aligned with said ink ejection chambers, wherein the print cartridge is mounted on the scanning carriage at a fixed angular position such that the straight linear array of ink ejection chambers is not perpendicular to the scan direction of the carriage.

2. The inkjet printing device of claim 1, wherein said internal ink conduit has an opening proximate to said back surface of said substrate, and wherein ink flows from said opening into said ink channel and across the portion of the back surface of said substrate.

3. The inkjet printing device of claim 1, wherein said internal ink conduit is defined by a first wall and a second wall, each wall having an end terminating proximate to the back surface of said substrate, so that ink flows through said ink conduit into said ink channel and across at least the portion of said back surface of said substrate and into said ink inlet channels.

4. The inkjet printing device of claim 1, wherein said ink channel allows said ink to flow across at least the portion of the back surface of said substrate and around one or more outer edges of said substrate and into said ink inlet channels.

5. The inkjet printing device of claim 1, wherein said ink channel allows said ink to flow across at least the portion of the back surface of said substrate and through a slot formed in said substrate and into said ink inlet channels.

6. The inkjet printing device of claim 3, wherein a gap between said back surface of said substrate and the ends of said first wall and said second wall is about 3 to 7 mils.

7. The inkjet printing device of claim 1, further including a bubble accumulation chamber for accumulating bubbles caused by warming of the ink by said substrate, said bubble accumulation chamber being in fluid communication with said ink inlet channels and said ink channel.

8. The inkjet printing device of claim 1, further comprising:

an external supply of ink, and

a pressure regulator in said internal ink chamber, said pressure regulator being in fluid communication with said internal ink chamber and said external supply of ink.

9. The inkjet printing device of claim 8, wherein said external supply of ink is releasably affixed to said housing.

10. The inkjet printing device of claim 8, wherein said external supply of ink is integral to said housing.

11. The inkjet printing device of claim 1, wherein said inlet channel length is minimized to allow high speed refill of the ink ejection chamber.

12. The inkjet printing device of claim 1, wherein said inlet channel length is less than 60 microns.

13. The inkjet printing device of claim 1, wherein said inlet channel length is less than 40 microns.

14. The inkjet printing device of claim 1, wherein the print cartridge is skewed with respect to the scanning carriage such that the straight linear array of ink ejection chambers is not perpendicular to the scan direction of the carriage.

18. The inkjet print cartridge of claim 14, wherein said ink channel allows said ink to flow across at least the portion of the back surface of said substrate and around one or more outer edges of said substrate and into said ink inlet channels.

15. An inkjet print cartridge comprising:

a housing having an internal ink chamber in fluid communication with an internal ink conduit;

a first wall and a second wall defining said internal ink conduit, said first and second walls being separate from walls forming said housing;

a substrate, having a plurality of outer edges, a front surface and a back surface, mounted on said housing and including a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, each of said ink ejection chambers having an ink inlet channel, said back surface having a portion across which ink flows;

an ink channel fluidically connecting said internal ink conduit with said ink inlet channels; and

a plurality of ink orifices aligned with said ink ejection chambers,

wherein said internal ink conduit has an opening proximate to said back surface of said substrate to allow ink to flow from said opening into said ink channel and across the portion of the back surface of said substrate.

wherein said ink channel allows said ink to flow across at least the portion of the back surface of said substrate and through a slot formed in said substrate and into said ink inlet channels.

16. The inkjet print cartridge of claim 15, wherein said each of said first and second walls has an end terminating proximate to the back surface of said substrate, so that ink flows through said internal ink conduit into said ink channel and across at least the portion of said back surface of said substrate and into said ink inlet channels.

17. The inkjet print cartridge of claim 16, wherein a gap between said back surface of said substrate and the ends of said first wall and said second wall is about 3 to 7 mils.

23. The inkjet print cartridge of claim 15, wherein each of the ink inlet channels has a same length.

24. The inkjet print cartridge of claim 23, wherein said ink inlet channel length is minimized to allow high speed refill of the ink ejection chamber.

25. The inkjet print cartridge of claim 23, wherein said ink inlet channel length is less than 60 microns.

26. The inkjet print cartridge of claim 23, wherein said ink inlet channel length is less than 40 microns.

19. An inkjet print cartridge comprising:

a housing having an internal ink chamber in fluid communication with an internal ink conduit;

a first wall and a second wall defininf said internal ink conduit, said first and second walls being seperate from walls forming said housing;

a substrate, having a plurality of outer edges, a front surface and a back surface, mounted on said housing and including a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, each of said ink ejection chambers having an ink inlet channel, said back surface having a portion across which ink flow;

an ink channel fluidically connecting said internal ink conduit with said ink inlet channels;

a plurality of ink orifices aligned with said ink ejection chambers, wherein said internal ink conduit has an opening proximate to said back surface of said substrate to allow ink to flow from said opening into said ink channel and across the portion of the back surface of said substrate; and

20. An inkjet print cartridge comprising:

a housing having an internal ink chamber in fluid communication with an internal ink conduit;

a first wall and a second wall defininf said internal ink conduit, said first and second walls being seperate from walls forming said housing;

a substrate, having a plurality of outer edges, a front surface and a back surface, mounted on said housing and including a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, each of said ink ejection chambers having an ink inlet channel, said back surface having a portion across which ink flow;

an ink channel fluidically connecting said internal ink conduit with said ink inlet channels;

a plurality of ink orifices aligned with said ink ejection chambers, wherein said internal ink conduit has an opening proximate to said back surface of said substrate to allow ink to flow from said opening into said ink channel and across the portion of the back surface of said substrate;

an external supply of ink; and

a pressure regulator in said internal ink chamber, said pressure regulator being in fluid communication with said internal ink chamber and said external supply of ink.

21. The inkjet print cartridge of claim 20, wherein said external supply of ink is releasably affixed to said housing.

22. The inkjet print cartridge of claim 20, wherein said external supply of ink is integral to said housing.

27. An inkjet printer comprising:

a scanning carriage for scanning along a scan direction;

a housing mounted in said scanning carriage, and having an internal ink chamber in fluid communication with an internal ink conduit;

a pressure regulator in said internal ink chamber, and in fluid communication with said internal ink chamber and an external supply of ink;

a substrate having a front surface and a back surface, said substrate being mounted on said housing and having a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, said ink ejection chambers forming a straight linear array substantially along a length of the substrate, each ink ejection chamber having an ink inlet channel of a same length;

an ink channel fluidically connecting said internal ink conduit with said ink inlet channels; and

a plurality of ink orifices aligned with said ink ejection chambers,

wherein the housing is skewed with respect to the scanning carriage at a fixed angular position such that the straight linear array of ink ejection chambers is not perpendicular to the scan direction of the carriage.

28. The inkjet printer of claim 27 wherein said pressure regulator includes:

a valve having an inlet and outlet, with the outlet in fluid communication with the housing;

a flexible member within the housing, the flexible member having a reference surface and an ink surface, the reference surface in communication with an outside atmosphere, the ink surface in fluid communication with the housing, a difference in pressure between the outside atmosphere and the housing causing the flexible member to bias toward the ink surface;

an actuator that receives a force from the ink surface of the flexible member, the actuator actuating the valve based upon a differential pressure between the reference surface and the outside atmosphere;

a source of ink for replenishing the printhead; and

an ink passageway for connecting the source of ink and the valve inlet.

29. The inkjet printer of claim 27 wherein said regulator includes:

a valve having an inlet and outlet, with the outlet in fluid communication with the housing;

a flexible member within the housing, the flexible member having a reference surface and an ink surface, the reference surface in communication with an outside atmosphere, the ink surface in fluid communication with the housing, a difference in pressure between the outside atmosphere and the housing causing the flexible member to bias toward the ink surface;

an actuator that receives a force from the ink surface of the flexible member, the actuator actuating the valve based upon the differential pressure between the reference surface and the outside atmosphere;

a source of ink for replenishing the printhead; and

an ink passageway for connecting the source of ink and the valve inlet.

30. An inkjet printer comprising:

a scanning carriage;

a housing mounted in said scanning carriage and having an internal ink chamber in fluid communication with an internal ink conduit;

a first wall and a second wall defining said internal ink conduit, said first and second walls being separate from walls forming said housing;

a pressure regulator in said internal ink chamber and in fluid communication with said internal ink chamber and an external supply of ink;

a substrate, having a front surface and a back surface, mounted on said housing and having a plurality of individual ink ejection chambers defined by a barrier layer formed on the front surface of said substrate and having an ink ejection element in each of said ink ejection chambers, each of said ink ejection chambers having an ink inlet channel, said back surface having a portion across which ink flows;

an ink channel fluidically connecting said ink conduit with said ink inlet channels; and

a nozzle member having a plurality of ink orifices formed therein, said nozzle member being positioned to overlie said barrier layer with said orifices aligned with said ink ejection chambers,

wherein said internal ink conduit has an opening proximate to said back surface of said substrate to allow ink to flow from said opening into said ink channel and across the portion of the back surface of said substrate.

31. A method of printing comprising:

providing a print cartridge mounted on a scanning carriage, the scanning carriage moving along a scan direction, the print cartridge comprising;

a housing having an internal ink chamber in fluid communication with an internal ink conduit;

a pressure regulator in the internal ink chamber, the pressure regulator in fluid communication with the internal ink chamber and an external ink supply;

a substrate mounted on the housing, the substrate having a front surface, a back surface, and a plurality of ink ejection chambers, the plurality of ink ejection chambers forming a straight linear array substantially along a length of the substrate, each ink ejection chamber having an ink inlet channel of a same length;

an ink channel fluidically connecting the internal ink conduit with the ink inlet channels; and

a plurality of ink orifices, each ink orifice being aligned with a respective ink ejection chamber;

supplying ink from the external ink supply through the pressure regulator of the print cartridge into the internal ink chamber through the ink channel and ink inlet channels and into the ink ejection chambers of the substrate; and

scanning the carriage along the scan direction while expelling ink onto a recording medium,

wherein the print cartridge is mounted on the scanning carriage at a fixed angular position such that the straight linear array of ink ejection chambers is not perpendicular to the scan direction of the carriage.

32. The method of claim 31, wherein the print cartridge is skewed with respect to the scanning carriage such that the straight linear array of ink ejection chambers is not perpendicular to the scan direction of the carriage.

33. The method of claim 31, wherein the internal ink conduit of the print cartridge is defined by a first wall and a second wall, the first and second walls being separate from walls forming the housing and each having an end terminating proximate to the back surface of the substrate, so that ink flows through the internal ink conduit into the ink channel across the back surface of the substrate and into the ink inlet channels.

34. The method of claim 33, wherein a gap between the back surface of the substrate and the ends of the first wall and the second wall is about 3 to 7 mils.