Capacitive touch sensor architecture with unique sensor bar addressing

• US 6,961,049 B2
• Filed: 06/21/2002
• Issued: 11/01/2005
• Est. Priority Date: 06/21/2002
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lim, Brian G., Mulligan, Roger C., Wong, Alex K., Badaye, Massoud
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US10/176,564
• Publication Number:
  US 20030234771A1
• Time in Patent Office: 1,229 Days
• Field of Search: 345/156, 345/173, 345/174, 178 1801- 1806, 341/33, 200/600
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard

Abstract

A capacitive touch sensor with symmetrical electrical interconnections for use with a touch sensor of a device is disclosed. The touch sensor includes several sensor bars, with a unique pair of lead lines coupled to each sensor bar. No inter-connection is provided between individual sensor bars. The sensor bars may be substantially transparent, and may comprise indium tin oxide. The touch sensor may be disposed on a viewing screen or proximate thereto. Also disclosed is a system for providing a signal for use in determining a touch location. The touch sensor receives an electrical field, receives a touch, and provides a signal representative of the modulation of the electrical field caused by the touch, wherein the modulation is a function of the location of the touch and the signal is suitable for use by controller to determine the location of the touch.

Claims

1. A capacitive touch sensor comprising:

a protective element covering a plurality of substantially parallel sensor bars arranged so that a touch on the protective element over one of the sensor bars produces measurable signals at least on that sensor bar and its first and second nearest neighbor sensor bars; and

a plurality of pairs of lead lines, the pairs of lead lines matching in number the plurality of sensor bars, each pair of load lines being associated with a different one of the sensor bars, one lead line of a pair of lead lines being coupled to the associated sensor bar at a first end of the associated sensor bar and the other lead line of the pair of lead lines being coupled to the associated sensor bar at a second end of the associated sensor bar.

2. The capacitive touch sensor of claim 1, wherein the sensor bars and lead lines are disposed on a flexible substrate.

3. The capacitive touch sensor of claim 2, wherein the flexible substrate comprises polyester.

4. The capacitive touch sensor of claim 1, wherein the protective element is replaceable.

5. The capacitive touch sensor claim 1, wherein the sensor bars comprise substantially optically transparent material.

6. The capacitive touch sensor of claim 1, wherein the sensor bars comprise indium tin oxide.

7. The capacitive touch sensor of claim 1, wherein the touch sensor is configured to be disposed over a viewing surface of a display device.

8. The capacitive touch sensor of claim 1, wherein the plurality of sensor bars are bounded by a first side and a second side that are approximately perpendicular to the direction of the sensor bars, and wherein a first group of the lead lines is routed along the first side and a second group of the lead lines is routed along the second side.

9. The capacitive touch sensor of claim 1, wherein each lead line of a pair has approximately equal electrical properties.

10. The capacitive touch sensor of claim 1, wherein the touch sensor is divided into a plurality of input areas, each input area being associated with a different set of sensor bars from the plurality of sensor bars, and further comprising a controller configured to receive signals generated by the touch sensor and to identify locations of at least two simultaneously occurring touches, one of the simultaneous touches occurring in a first one of the plurality of input areas and another of the simultaneous touches occurring in a second one of the plurality of input areas.

11. The capacitive touch sensor of claim 10, wherein at least two of the plurality of input areas comprise a playing areas associated with an entertainment activity.

12. The capacitive touch sensor of claim 11, wherein the entertainment activity comprises an electronically performed game.

13. The capacitive touch sensor of claim 11, wherein the playing areas are arranged side-by-side.