MESH PATTERNS FOR TOUCH SENSOR ELECTRODES

• US 20130207911A1
• Filed: 11/30/2012
• Published: 08/15/2013
• 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: WEAVER, Billy L., GEAGHAN, Bernard O., HABLE, Brock A., BARTON, Roger W.
• Granted Patent: US 9,360,971 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 touch screen sensor, comprising:

an upper electrode layer comprising an array of composite electrodes comprised of a plurality of continuous micro-wire conductors disposed in a first pattern;

a lower electrode layer comprising a plurality of 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;

wherein the composite electrodes of the upper electrode layer form interior regions electrically isolated from the composite electrodes, the regions comprised of discontinuous micro-wire conductors.

2. The touch screen sensor of claim 1, wherein the discontinuous micro-wire conductors of the interior regions are disposed in a second pattern.

3. The touch screen sensor of claim 2, wherein the first is the same as the second pattern.

4. The touch screen sensor of claim 2, wherein the interior regions are more pervious to electrical fields than the composite electrodes.

5. The touch screen sensor of claim 2, wherein the upper and lower electrode layers are oriented such that the interior regions of the composite electrodes of the upper electrode layer are positioned at the nodes.

6. The touch screen sensor of claim 2, wherein the first or second pattern comprises repeating squares, diamonds, hexagons, or octagons.

7. The touch screen sensor of claim 6, wherein the repeating squares, diamonds, hexagons, or octagons are not all the same size.

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

a mesh of patterned conductive micro-wires having interior regions of patterned discontinuous patterned conductive micro-wires.

9. The micro-wire based electrode of claim 8, wherein the interior regions are patterned to include breaks in the micro-wires.

10. The micro-wire based electrode of claim 8, wherein the interior regions include breaks in the micro-wires.

11. The micro-wire based electrode of claim 8, wherein micro-wire comprise conductors having a trace width of about X+0.5 in units of micrometers;

and an open area fraction between about [95−

X] % and 99.5%, wherein 0≦

X≦

4.5.

12. The micro-wire based electrode of claim 8, 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.

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

a plurality of continuous micro-conductors that define a first mesh pattern with a first characteristic average cell spacing, the first mesh pattern having interior regions that comprise discontinuous micro-conductors with a second characteristic average cell spacing; and

wherein the interior regions extend over an area having lateral dimensions that are larger than the lateral dimensions of the area of the second characteristic average cell spacing.

14. The micro-wire based electrode of claim 13, wherein first and second characteristic average cell spacings are substantially equal.

15. The micro-wire based electrode of claim 13, wherein the first characteristic average cell spacing is larger than the second characteristic average cell spacing.

16. The micro-wire based electrode of claim 13, wherein the first characteristic average cell spacing is an integral multiple of the second characteristic average cell spacing.

17. The micro-wire based electrode of claim 13, wherein the mesh pattern is a regular polygonal mesh.

18. The micro-wire based electrode of claim 13, wherein the mesh pattern is a pseudo-random mesh.

19. The micro-wire based electrode of claim 13, 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.

20. The micro-wire based electrode of claim 13, wherein the first character average cell spacing is variable as a function of location from the center of the electrode.

21. The micro-wire based electrode of claim 13, further comprising islands of electrically continuous micro-wires disposed with the interior regions.

22. The micro-wire based electrode of claim 21, wherein the islands are disposed according to a mesh pattern with third characteristic average cell spacing that is substantially equal to the first characteristic average cell spacing.

23. The micro-wire based electrode of claim 13, wherein the first characteristic average cell spacing is less near the center of the electrode and greater further away from the center of the electrode.