Touch sensors incorporating capacitively coupled electrodes

• US 7,724,243 B2
• Filed: 11/30/2005
• Issued: 05/25/2010
• Est. Priority Date: 12/22/2004
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Geaghan, Bernard O.
• Primary Examiner(s): Dharia; Prabodh M
• Application Number:
  US11/290,014
• Publication Number:
  US 20060132462A1
• Time in Patent Office: 1,637 Days
• Field of Search: 345/100, 345/104, 345/156, 345173-179, 178 1801- 1806, 200/600, 361/280, 324/786
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

The present invention provides touch sensors that incorporate electrodes that are capacitively coupled through a dielectric layer to one or more resistive touch sensing layers, for example for linearizing the electric field across the resistive layer of an analog capacitive touch screen or for addressing the conductive elements of a matrix type capacitive touch screen. Such a construction allows for new manufacturing methods and new ways of constructing touch sensors.

Claims

1. A touch sensor comprising:

a resistive layer configured for sensing a touch to the touch sensor;

a layer of continuous resistor material;

a plurality of more than four electrodes, each of the plurality of electrodes electrically connected to the layer of continuous resistor material along a length of the resistor material; and

a dielectric layer disposed between the plurality of electrodes and the resistive layer,

wherein each of the plurality of electrodes is capacitively coupled to the resistive layer through the dielectric layer to form a respective one of a plurality of capacitors, and

wherein the plurality of electrodes are positioned to provide a uniformly distributed driving signal to the resistive layer.

2. The touch sensor of claim 1, wherein the dielectric layer is disposed between the plurality of electrodes electrically connected to the layer of continuous resistor material and the resistive layer.

3. The touch sensor of claim 2, wherein the resistive layer has a top surface, and wherein the dielectric layer is disposed over and in electrical communication with the entire top surface of the resistive layer.

4. The touch sensor of claim 2, wherein the resistive layer has a top surface, and wherein the dielectric layer is disposed over and in electrical communication with only a portion of the top surface of the resistive layer.

5. A method for making a touch sensor comprising:

providing an article including a resistive layer suitable for sensing a touch;

providing a layer of continuous resistor material;

providing a plurality of more than four electrodes, each of the plurality of electrodes mutually electrically connected to the layer of continuous resistor material along a length of the resistor material;

providing a dielectric layer that capacitively couples each of the plurality of electrodes to the resistive layer to form a respective one of a plurality of capacitors, wherein the plurality of electrodes are positioned to provide a uniformly distributed driving signal to the resistive layer; and

electrically coupling the plurality of electrodes and the layer of continuous resistor material to controller electronics configured to communicate signals to and from the resistive layer through the plurality of electrodes and the layer of continuous resistor material.

6. A touch sensor comprising:

a plurality of electrically isolated resistive elements configured for sensing a touch to the touch sensor;

an electrode strip comprising a plurality of more than four electrodes along a length of the electrode strip, the plurality of electrodes individually electrically connected to controller electronics; and

a dielectric layer,

wherein the electrode strip is disposed such that each of the plurality of electrodes is capacitively coupled to one of the resistive elements through the dielectric layer to form a respective one of the plurality of capacitors.