Ink delivery system for an inkjet printhead

• US 5,953,029 A
• Filed: 04/04/1997
• Issued: 09/14/1999
• Est. Priority Date: 04/02/1992
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Childers, Winthrop D., Steinfield, Steven W., Trueba, Kenneth E., McClelland, Paul H., Keefe, Brian J.
• Primary Examiner(s): HARTARY, JOSEPH W
• Application Number:
  US08/832,991
• Time in Patent Office: 893 Days
• Field of Search: 347/84, 347/75, 347/85, 347/45, 347/46, 347/47, 347/44, 347/63-65, 347/57-59, 347/87, 347/50
• US Class Current: 347/65
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04546 Multiplexing
• CPC Class Codes: B41J 2/0458 controlling heads based on heating elements forming bubbles
• CPC Class Codes: B41J 2/14024 Assembling head parts
• 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 2/14129 Layer structure
• CPC Class Codes: B41J 2/14145 Structure of the manifold
• CPC Class Codes: B41J 2/14201 Structure of print heads with piezoelectric elements
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• CPC Class Codes: B41J 2/1603 of the front shooter type
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1634 laser machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• 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 2/17526 : Electrical contacts to the cartridge
• CPC Class Codes: B41J 2/1753 : Details of contacts on the cartridge, e.g. protection of contacts
• 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 2202/13 : Heads having an integrated circuit

Abstract

This invention provides an improved ink flow path between an ink reservoir and vaporization chambers in an inkjet printhead. In the preferred embodiment, a barrier layer containing ink channels and vaporization chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two linear arrays of heater elements, and each orifice in the nozzle member is associated with a vaporization chamber and heater element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the vaporization chambers.

Claims

1. A printer comprising:

printer electrodes providing energization signals for energizing ink injection elements on a printhead; and

a print cartridge installed in said printer having contact pads making electrical contact to said printer electrodes, said print cartridge further comprising;

a substrate, said substrate having a front surface for facing a recording medium and a back surface opposite said front surface, said substrate having a plurality of ink firing chambers on said front surface of said substrate, with an ink firing element in each ink firing chamber, each said ink firing element being energized pursuant to said energization signals, said substrate having a first outer edge along a periphery of said substrate, said first outer edge being substantially parallel to a first row of ink firing elements located in a first row of associated ink firing chambers, said substrate having a second outer edge along said periphery of said substrate, said second outer edge being substantially parallel to a second row of ink firing elements located in a second row of associated ink firing chambers, said substrate having a substantial central interior portion on said front surface excluding ink inlet passages to said ink firing chambers;

an ink channel connecting a source of ink with said ink firing chambers, said ink channel allowing ink to flow from said back surface of said substrate, around said first outer edge and said second outer edge of said substrate, and to said front surface of said substrate; and

a barrier portion having formed in it a separate inlet passage for each ink firing chamber, each said separate ink inlet passage being completely defined within outer boundaries of said front surface of said substrate, ink flowing around said first outer edge and said second outer edge entering said separate inlet passage for each ink firing chamber for allowing refill of said ink firing chamber, a central section of said barrier portion having no ink passages covering said central interior portion of said substrate between said first row and said second row of said ink firing chambers,

said first row of associated ink firing chambers receiving ink around said first outer edge, and said second row of associated ink firing chambers receiving ink around said second outer edge.

2. The printer of claim 1 wherein said ink source comprises an ink reservoir.

3. The printer of claim 2 wherein said ink reservoir is located within said print cartridge.

4. The printer of claim 1 wherein said print cartridge includes a printhead surface for facing a recording medium and further includes a headland area in which resides said substrate, said headland area including a wall, wherein said substrate is mounted in said headland area such that said first outer edge is spaced from and parallel to said wall.

5. The printer of claim 1 further comprising a flexible tape secured to said front surface of said substrate over each said separate inlet passage, said flexible tape having a plurality of orifices, each of said orifices being aligned with a respective ink firing chamber.

6. The printer of claim 5 wherein said contact pads are located on said flexible tape.

7. The printer of claim 1 wherein said separate inlet passage for each ink firing chamber comprises a barrier layer formed directly on said front surface of said substrate using photolithographic techniques.

8. The printer of claims 1 further comprising nozzles overlying each ink firing chamber, wherein said barrier portion is a barrier layer separate from a nozzle member in which said nozzles are formed.

9. A printer comprising:

printer electrodes providing energization signals for energizing ink injection elements on a printhead; and

a print cartridge installed in said printer having contact pads making electrical contact to said printer electrodes, said print cartridge further comprising;

a substrate cut from a wafer, said substrate having first and second outer edges which are longer than third and fourth outer edges, said first and second outer edges defining ink feed channels for passing ink from a back surface of said substrate around said first and second outer edges of said substrate to a plurality of firing chambers formed on a front surface of said substrate, said substrate having a central interior portion on said front surface excluding ink feed channels to said firing chambers and including demultiplexing circuitry;

electrodes along said third and fourth outer edges, but not along said first and second outer edges, on said front surface of said substrate and connected to said demultiplexing circuitry for receiving electrical signals from said printer to selectively activate individual firing elements in each firing chamber, wherein the number of electrodes is less than the number of firing chambers; and

a barrier portion having formed in it a separate inlet passage for each ink firing chamber, each said separate ink inlet passage being completely defined within outer boundaries of said front surface of said substrate, ink flowing around said first and second outer edges entering said separate inlet passage for each ink firing chamber for allowing refill of said ink firing chamber,

said firing chambers being formed in two parallel rows, a first row receiving ink around said firs outer edge and a second row receiving ink around said second outer edge, a central section of said barrier portion having no ink passages covering said central interior portion on said front surface of said substrate between said two parallel rows of firing chamber.

10. The printer of claim 9 further comprising an ink source in fluid communication with said ink feed channels.

11. The printer of claim 10 wherein said ink source is located within said print cartridge.

12. The printer of claim 9 further comprising nozzles overlying each ink firing chamber, wherein said barrier portion is a barrier layer separate from a nozzle member in which said nozzles are formed.