Ink jet printhead chip with volumetric ink ejection mechanisms

• US 7,182,436 B2
• Filed: 08/12/2005
• Issued: 02/27/2007
• Est. Priority Date: 06/09/1998
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Primary Examiner(s): Do; An H.
• Application Number:
  US11/202,331
• Publication Number:
  US 20050270336A1
• Time in Patent Office: 564 Days
• Field of Search: 347/54, 347/56, 347/65
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14475 characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 : with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

An inkjet printhead chip includes a substrate that defines a plurality of ink supply channels. A drive circuitry layer is positioned in the substrate. A plurality of nozzle arrangements is positioned on the substrate. Each nozzle arrangement includes a nozzle chamber structure arranged on the substrate and defining walls of a nozzle chamber in fluid communication with a respective ink supply channel. A deformable roof structure is arranged on the nozzle chamber structure. The roof structure is deformable on receipt of an actuating signal from the drive circuitry, reciprocally to reduce and enlarge a volume of the nozzle chamber. The roof structure defines an ink ejection port such that, upon such reduction and enlargement, a drop of ink is ejected from the ink ejection port.

Claims

1. An inkjet printhead integrated circuit that comprises

a substrate that defines a plurality of ink supply channels;

a drive circuitry layer that is positioned in the substrate; and

a plurality of nozzle arrangements that is positioned on the substrate, each nozzle arrangement comprising

a nozzle chamber structure arranged on the substrate and defining walls of a nozzle chamber in fluid communication with a respective ink supply channel; and

a deformable roof structure arranged on the nozzle chamber structure and being at least partially defined by a plurality of discrete actuators, each actuator being configured to be heated on receipt of an electrical signal from the drive circuitry so as to experience differential thermal expansion and contraction, reciprocally to reduce and enlarge a volume of the nozzle chamber, the roof structure defining an ink ejection port such that, upon such reduction and enlargement, a drop of ink is ejected from the ink ejection port.

2. An inkjet printhead integrated circuit as claimed in claim 1, in which the walls of each nozzle chamber are the product of an etching process carried out on the substrate so that each nozzle chamber is positioned in the substrate.

3. An inkjet printhead integrated circuit as claimed in claim 2, in which each actuator extends towards the ink ejection port, a heating circuit being embedded in the actuator to receive the electrical signal from the drive circuitry layer, the heating circuit being positioned so that the actuator is subjected to the differential thermal expansion and contraction to displace the actuator towards and away from the respective ink supply channel.

4. An inkjet printhead integrated circuit as claimed in claim 3, in which each ink ejection port is positioned centrally in the roof structure and the actuators radially with respect to the ink ejection port.

5. An inkjet printhead integrated circuit as claimed in claim 4, in which each roof structure includes a rim that defines the ink ejection port, the rim being supported above the respective ink inlet channel with support arms that extend from the rim to the drive circuitry layer, the actuators being interposed between consecutive support arms.

6. An inkjet printhead integrated circuit as claimed in claim 5, in which the support arms and the actuators are configured so that ink in the nozzle chamber forms a meniscus between each support arm and each adjacent actuator to permit displacement of the actuators while inhibiting egress of ink from between the support arms and the actuators.

7. An inkjet printhead integrated circuit as claimed in claim 3, in which each actuator includes an actuating portion that is connected to the drive circuitry layer and an ink displacement member that is positioned on the actuating portion to extend towards the ink ejection port.

8. An inkj et printhead integrated circuit as claimed in claim 3, in which each actuator is of polytetrafluoroethylene while each heating circuit is one of the materials in a group including gold and copper.