Mesh patterns for touch sensor electrodes

• US 9,639,228 B2
• Filed: 04/26/2016
• Issued: 05/02/2017
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Barton, Roger W., Geaghan, Bernard O., Hable, Brock A., Weaver, Billy L
• Primary Examiner(s): Bibbins, Latanya
• Application Number:
  US15/138,418
• Publication Number:
  US 20160253003A1
• Time in Patent Office: 371 Days
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04111 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 3/044 by capacitive means
• 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 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: H01B 5/00 Non-insulated conductors or conductive bodies characterised by their form
• CPC Class Codes: H01B 5/14 comprising conductive layers or films on insulating-supports
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

An electrode for a touch sensitive device includes micro-wire conductors arranged to define an electrically continuous area and to include interior regions that are electrically discontinuous. The electrically continuous area may be patterned according to a one pattern, and the interior pattern may be patterned according to another pattern.

Claims

1. A micro-wire based electrode for use in a touch sensor, the electrode comprising:

a plurality of continuous micro-wire conductors disposed in a first pattern; and

interior regions comprising a plurality of discontinuous conductive micro-wires disposed in a second pattern, the interior regions bounded by the continuous micro-wire conductors and electrically isolated from the continuous micro-wire conductors, the second pattern a two-dimensional mesh pattern.

2. The micro-wire based electrode of claim 1, wherein the first pattern has a first characteristic average cell spacing, the second pattern has a second characteristic average cell spacing, and the interior regions extend over an area having lateral dimensions larger than the second characteristic average cell spacing.

3. The micro-wire based electrode of claim 2, wherein the first and second characteristic average cell spacings are substantially equal.

4. The micro-wire based electrode of claim 2, wherein the first characteristic average cell spacing is larger than the second characteristic average cell spacing.

5. The micro-wire based electrode of claim 2, wherein the first characteristic average cell spacing is an integral multiple of the second characteristic average cell spacing.

6. The micro-wire based electrode of claim 2, wherein the first characteristic average cell spacing is greater near the center of the electrode and lesser further away from the center of the electrode.

7. The micro-wire based electrode of claim 2, wherein the first characteristic average cell spacing is lesser near the center of the electrode and greater further away from the center of the electrode.

8. The micro-wire based electrode of claim 2, wherein the first characteristic average cell spacing is variable as a function of location from the center of the electrode.

9. The micro-wire based electrode of claim 1, wherein the plurality of continuous micro-wire conductors and the plurality of discontinuous conductive micro-wires are disposed on a common reference mesh.

10. The micro-wire based electrode of claim 1, wherein the continuous micro-wire conductors and the discontinuous conductive micro-wires have a trace width of about X+0.5 in units of micrometers;

and the micro-wire based electrode has an open area fraction between about [95−

X]% and 99.5%, wherein 0≦

X≦

4.5.

11. The micro-wire based electrode of claim 10, wherein the open area fraction is between about [98.5−

(2.5X÷

3.5)]% and [99.5−

(X÷

3.5)]% wherein 0≦

X≦

3.5.

12. The micro-wire based electrode of claim 1, wherein the interior regions are more pervious to electrical fields than electrically continuous regions of the micro-wire based electrode.

13. The micro-wire based electrode of claim 1, wherein the first or second pattern comprises repeating squares, diamonds, hexagons, or octagons.

14. The micro-wire based electrode of claim 13, wherein the repeating squares, diamonds, hexagons, or octagons are not all the same size.

15. The micro-wire based electrode of claim 1, further comprising islands of electrically continuous micro-wires disposed within the interior regions.

16. A touch screen sensor, comprising:

an upper electrode layer comprising a plurality of upper electrodes, the upper electrodes being micro-wire based electrodes according to claim 1;

a lower electrode layer comprising a plurality of lower electrodes;

wherein the upper and lower electrodes are separated by a dielectric layer, and together define an electrode matrix having nodes where the upper and lower electrodes cross over.

17. The touch screen sensor of claim 16, wherein the upper and lower electrode layers are oriented such that the interior regions of the upper electrodes are positioned at the nodes.

18. The touch screen sensor of claim 16, wherein the interior regions of the upper electrodes are more pervious to electrical fields than electrically continuous regions of the upper electrodes.

19. A touch screen sensor, comprising:

an upper electrode layer comprising a plurality of upper electrodes;

a lower electrode layer comprising a plurality of lower electrodes;

wherein the upper and lower electrodes are separated by a dielectric layer, and together define an electrode matrix having nodes where the upper and lower electrodes cross over, and wherein the upper and lower electrodes are micro-wire based electrodes according to claim 1.

20. A touch sensor comprising a plurality of the micro-wire based electrodes of claim 1, the touch sensor configured to overlay a viewable portion of a display.