Mesh patterns for touch sensor electrodes

• US 10,019,110 B2
• Filed: 09/09/2016
• Issued: 07/10/2018
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weaver, Billy L., Barton, Roger W., Herdtle, Thomas, Hable, Brock A.
• Primary Examiner(s): Bibbins, Latanya
• Application Number:
  US15/260,640
• Publication Number:
  US 20160378260A1
• Time in Patent Office: 669 Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

An electrode for a touch sensitive device includes micro-wire conductors arranged to define an electrically continuous electrode trunk area, and including branching elements which extend outward from the electrode trunk area. The electrically continuous trunk area is patterned coincident an underlying reference mesh pattern, as are the branching elements.

Claims

1. An electrode comprising a two-dimensional array of opaque metallic micro-wires extending along orthogonal first and second directions, a plurality of the metallic micro-wires having breaks therein to form an array of discontinuous micro-wires defining a conductive pattern of continuous micro-wires disposed along the first direction and a plurality of electrically continuous branching elements electrically connected to the conductive pattern and extending outward therefrom.

2. The electrode of claim 1, wherein the conductive pattern defines an electrode trunk, and the branching elements extend outward from the electrode trunk.

3. The electrode of claim 2, wherein the conductive pattern defines further electrode trunks, and the branching elements extend outward from these further electrode trunks.

4. The electrode of claim 2, wherein the branching elements substantially conform to a diamond shape centered on the electrode trunk.

5. The electrode of claim 2, wherein the branching elements are electrically coupled to the electrode trunk at no more than one terminal area.

6. The electrode of claim 1, wherein the branching elements are arranged substantially along the second direction.

7. The electrode of claim 1, wherein a distance between branching elements is greater than a characteristic average cell spacing of the two-dimensional array of metallic micro-wires.

8. The electrode of claim 1, wherein a length of each of the branching elements is greater than a characteristic average cell spacing of the two-dimensional array of metallic micro-wires.

9. The electrode of claim 8, wherein the length of at least some of the branching elements is greater than five times the characteristic average cell spacing.

10. The electrode of claim 1, wherein the metallic micro-wires have a trace width of 0.5 to 5.0 micrometers.

11. The electrode of claim 1, wherein the metallic micro-wires have a trace width of X+0.5 in units of micrometers, and an open area fraction between [95−

X]% and 99.5%, wherein 0≤

X≤

4.5.

12. The electrode of claim 1, wherein the array of discontinuous micro-wires defines a regular polygonal lattice.

13. The electrode of claim 1, wherein the array of discontinuous micro-wires defines a pseudo-random lattice.

14. A touch sensor comprising a first electrode layer, the first electrode layer comprising a plurality of electrodes according to claim 1.

15. The touch sensor of claim 14, further comprising a second electrode layer and a dielectric layer separating the first and second electrode layers.

16. The touch sensor of claim 15, wherein the second electrode layer comprises electrodes disposed along the second direction.

17. The touch sensor of claim 14, wherein at least some of the branching elements of an electrode in the plurality of electrodes are interleaved with branching elements of another electrode in the plurality of electrodes.

18. A display comprising the touch sensor of claim 14 overlaying a viewable portion of the display.

19. An electrode layer comprising a plurality of electrodes, each electrode in the plurality of electrodes comprising a two-dimensional array of metallic micro-wires extending along orthogonal first and second directions, a plurality of the metallic micro-wires having breaks therein to form an array of discontinuous micro-wires defining a conductive pattern of continuous micro-wires disposed along the first direction and a plurality of electrically continuous branching elements electrically connected to the conductive pattern and extending outward therefrom, wherein at least some of the branching elements of an electrode in the plurality of electrodes are interleaved with branching elements of another electrode in the plurality of electrodes.

20. A touch sensor comprising the electrode layer of claim 19.