Touch sensitive device with multilayer electrode having improved optical and electrical performance

• US 8,730,184 B2
• Filed: 12/16/2009
• Issued: 05/20/2014
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Nirmal, Manoj, Maki, Stephen P., McClure, Donald J., Woody, Joseph W. V
• Primary Examiner(s): GIESY, ADAM
• Application Number:
  US12/639,363
• Publication Number:
  US 20110139516A1
• Time in Patent Office: 1,616 Days
• Field of Search: None
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• 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

Abstract

A touch sensor including one or more multilayer electrodes, said electrodes including at least two transparent or semitransparent conductive layers separated by a transparent or semitransparent intervening layer. The intervening layer includes electrically conductive pathways between the first and second conductive layers to help reduce interfacial reflections occurring between particular layers in devices incorporating the conducting film or electrode.

Claims

1. A sensor for use in a touch sensitive device, the sensor comprising one or more electrodes disposed on a substrate, at least one or more of the electrodes comprising:

a first transparent or semitransparent conductive layer;

a second transparent or semitransparent conductive layer; and

a transparent or semitransparent intervening layer located between the first and second conductive layers, the intervening layer including electrically conductive pathways between the first and second conductive layers, such that when the sensor is used in a touch sensitive device, each of the first transparent or semitransparent conductive layer, second transparent or semitransparent conductive layer, and transparent or semitransparent intervening layer, together, function as a single electrode.

2. The sensor of claim 1, wherein the first and second conductive layers each comprise a transparent or semitransparent conductive oxide.

3. The sensor of claim 1, wherein the one or more electrodes comprises a single, un-patterned electrode.

4. The sensor of claim 1, wherein the one or more electrodes comprises patterned electrodes disposed on the substrate to form a matrix.

5. The sensor of claim 1, wherein the one or more electrodes comprises a first and second electrode disposed on the same layer.

6. The sensor of claim 1, wherein the intervening layer comprises a dielectric polymer or an inorganic dielectric material.

7. The sensor of claim 1, wherein the intervening layer comprises a conductive layer having an index of refraction different from the indexes of refraction of the first and second conductive layers.

8. The sensor of claim 1, wherein the electrically conductive pathways comprise conductive links extending through apertures between the first and second conductive layers.

9. The sensor of claim 1, wherein the intervening layer comprises a binder and wherein the electrically conductive pathways comprise conductive particles suspended in the binder and extending between the first and second conductive layers.

10. The sensor of claim 1, wherein the thickness of the first conductive layer is substantially identical to a thickness of the second conductive layer.

11. The sensor of claim 1, wherein the substrate comprises polyethylene terephthalate.

12. The sensor of claim 11, further comprising an overlayment layer, the electrodes disposed between the substrate and the overlayment layer.

13. The sensor of claim 12, wherein the overlayment layer comprises polyethylene terephthalate or glass.

14. The sensor of claim 1, wherein the electrodes are diposed in a honeycomb pattern.

15. The sensor of claim 1, wherein the electrodes are disposed on the substrate to form an electrode matrix.

16. The sensor of claim 1, further comprising a display, and wherein the sensor is disposed upon the display such that elements appearing on a viewing screen of the display may be seen through the sensor.