Bubble-tolerant high flow printhead architecture

• US 10,525,710 B2
• Filed: 02/05/2018
• Issued: 01/07/2020
• Est. Priority Date: 02/06/2017
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Memjet Technology Ltd. (Memjet Limited)
• Inventors: Thelander, Jason, Burke, David, Thomas, Andrew
• Primary Examiner(s): Lin, Erica S
• Application Number:
  US15/888,857
• Publication Number:
  US 20180222227A1
• Time in Patent Office: 701 Days
• Field of Search: None
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14145 Structure of the manifold
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• CPC Class Codes: B41J 2/155 for line printing
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/1752 Mounting within the printer
• CPC Class Codes: B41J 2/17523 Ink connection
• CPC Class Codes: B41J 2/19 for removing air bubbles
• CPC Class Codes: B41J 2/21 for multi-colour printing
• CPC Class Codes: B41J 2/2103 Features not dealing with the colouring process per se, e.g. construction of printers or heads, driving circuit adaptations
• CPC Class Codes: B41J 2002/14362 Assembling elements of heads
• CPC Class Codes: B41J 2002/14419 Manifold
• CPC Class Codes: B41J 2002/14491 Electrical connection
• CPC Class Codes: B41J 2202/19 Assembling head units
• CPC Class Codes: B41J 2202/20 Modules
• CPC Class Codes: B41J 2202/21 Line printing
• CPC Class Codes: B41J 25/34 Bodily-changeable print heads or carriages

Abstract

An inkjet printhead includes: a manifold having an ink supply channel and a lower surface with a longitudinal ink cavity defined therein; a shim attached to the lower surface so as to bridge across the longitudinal ink cavity, the shim having a plurality of shim apertures for receiving ink from the longitudinal ink cavity; and a plurality of printhead chips attached to the shim. A plurality of through-holes are defined in the manifold to provide fluid communication between the ink supply channel and the longitudinal ink cavity. Each through-hole has a first portion with a first end defined in the roof and a second portion extending through a sidewall of the ink cavity such that the shim seals an end of the second portion.

Claims

1. An inkjet printhead comprising:

a rigid elongate manifold having an upper portion defining at least one longitudinal ink supply channel, a lower portion defining at least one a longitudinal ink cavity extending parallel with the longitudinal ink supply channel, and a plurality of through-holes providing fluid communication between the longitudinal ink supply channel and the longitudinal ink cavity, the through-holes extending perpendicular to the longitudinal ink supply channel and the longitudinal ink cavity;

a shim sealingly attached to a lower surface of the manifold so as to bridge across the longitudinal ink cavity, the shim having a plurality of shim apertures for receiving ink from the longitudinal ink cavity; and

a plurality of printhead chips attached to the shim, each printhead chip receiving ink from the longitudinal ink cavity via one or more of the shim apertures.

2. The inkjet printhead of claim 1, wherein each through-hole has a first portion with one end defined in a roof of the longitudinal cavity and a second portion extending through a respective sidewall of the longitudinal cavity and terminating at lower surface of the manifold, wherein at least part of the second portion of each through-hole is offset from a respective printhead chip.

3. The inkjet printhead of claim 2, wherein each second portion is configured to enable an air bubble to rise from a respective printhead chip towards the ink supply channel.

4. The inkjet printhead of claim 3, wherein each second portion defines a notch in a respective sidewall.

5. The inkjet printhead of claim 4, wherein each through-hole is circular and the first and second portions are generally semi-circular.

6. The inkjet printhead of claim 1 further comprising a longitudinal rib dividing the longitudinal ink cavity into longitudinal ink feed channels at either side of the rib, the rib having a lower surface coplanar with the lower surface of the manifold.

7. The inkjet printhead of claim 6, wherein the shim is bonded to the lower surfaces of the rib and the manifold.

8. The inkjet printhead of claim 6, wherein each printhead chip has a central portion aligned with the rib and opposite side portions overlapping with respective longitudinal ink feed channels.

9. The inkjet printhead of claim 1, wherein the shim is a one-piece structure for bonding a plurality of rows of printhead chips.

10. The inkjet printhead of claim 1, wherein the manifold is a one-piece structure.

11. The inkjet printhead of claim 1, wherein the shim is comprised of a metal alloy having a CTE of 5 ppm/°

C. or less.

12. The inkjet printhead of claim 11, wherein the shim is comprised of an alloy of iron and at least one other metal selected from the group consisting of:

nickel, cobalt and chromium.

13. The inkjet printhead of claim 1, wherein the manifold is comprised of a same material as the shim.