Printhead having heated shield plate

• US 10,239,316 B2
• Filed: 02/05/2018
• Issued: 03/26/2019
• 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): Vo, Anh T. N.
• Application Number:
  US15/888,841
• Publication Number:
  US 20180222226A1
• Time in Patent Office: 414 Days
• 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 a plurality of ink outlets defined in a manifold surface; a plurality of printhead chips mounted to the manifold surface and aligned with the ink outlets; a PCB mounted to the manifold surface and offset from the ink outlets, the PCB being electrically connected to the printhead chips; and a shield plate covering the PCB. The shield plate has one face in thermal contact with the PCB and an exposed opposite face defining a lower surface of the printhead.

Claims

1. An inkjet printhead comprising:

a manifold having a plurality of ink outlets defined in a manifold surface;

a plurality of printhead chips mounted to the manifold surface and aligned with the ink outlets;

a PCB mounted to the manifold surface and offset from the ink outlets, the PCB being electrically connected to the printhead chips; and

a shield plate covering the PCB,

wherein the shield plate has one face in thermal contact with the PCB and an exposed opposite face defining a lower surface of the printhead.

2. The inkjet printhead of claim 1, wherein the shield plate is electrically insulating.

3. The inkjet printhead of claim 1, wherein the printhead chips are mounted to the manifold surface via a shim.

4. The inkjet printhead of claim 3, wherein the shield plate intimately contacts a lower surface of the PCB.

5. The inkjet printhead of claim 1, wherein the PCB is a rigid PCB.

6. The inkjet printhead of claim 1, wherein the lower surface of the PCB is coplanar with a lower surface of the shim.

7. The inkjet printhead of claim 6, wherein the PCB is thicker than the shim and the manifold surface is stepped to accommodate the PCB and the shim having respective coplanar lower surfaces.

8. The inkjet printhead of claim 6, wherein the shield plate is bonded to the PCB and part of the shim.

9. The inkjet printhead of claim 6, wherein the shim has at least one void region offset from the printhead chips, the void region thermally isolating part of the shield plate from the manifold.

10. The inkjet printhead of claim 1 comprising a row of printhead chips, wherein the PCB extends longitudinally adjacent the row of printhead chips.

11. The inkjet printhead of claim 10 comprising first and second rows of printhead chips, the first row of printhead chips having a respective first PCB and the second row of printhead chips having a respective second PCB, wherein the first and second PCBs are positioned at opposite distal longitudinal sides of the first and second rows of printhead chips.

12. The inkjet printhead of claim 11, wherein the first and second PCBs wrap at least partially around ends of the first and second rows of printhead chips.

13. The inkjet printhead of claim 11, wherein a central longitudinal region is defined between the first and second rows of printhead chips.

14. The inkjet printhead of claim 13, wherein the shield plate is a perimeter shield plate covering the first and second PCBs, the perimeter shield plate having a central leg covering the central longitudinal region.

15. The inkjet printhead of claim 14, wherein the first and second rows of printhead chips are mounted to the manifold via a shim, and wherein the shim has at least one void region coincident with the central longitudinal region, the void region thermally isolating the central leg of the shield plate from the manifold.

16. The inkjet printhead of claim 1, wherein the shim has a thickness in the range of 100 to 1000 microns.