Capacitive touch sensor architecture with unique sensor bar addressing

• US 20030234771A1
• Filed: 06/21/2002
• Published: 12/25/2003
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Badaye, Massoud, Lim, Brian G., Mulligan, Roger C., Wong, Alex K.
• Granted Patent: US 6,961,049 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 for use proximate to a surface of a device, comprising:

a plurality of sensor bars, each sensor bar comprising a first end and a second end; and

a plurality of pairs of lead lines, wherein one lead line of a pair of lead lines is coupled to one of the sensor bars at its first end and the other lead line of the pair is coupled to the sensor bar at its second end, and further wherein each sensor bar of the plurality of sensor bars is coupled to a different one of the plurality of pairs of lead lines.

2. The capacitive touch sensor of claim 1, wherein the sensor bars are arranged substantially parallel.

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

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

5. The capacitive touch sensor of claim 1, wherein the visual device is a touch pad.

6. The capacitive touch sensor of claim 1, wherein the touch sensor is configured to be disposed on the viewing surface.

7. The capacitive touch sensor of claim 1, wherein:

the plurality of sensor bars are generally disposed lengthwise in a first direction, wherein the plurality of sensor bars are bounded in that first direction by a first side and by a second side, and further wherein the first side and the second side are approximately parallel to the first direction; and

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, wherein a sum of the number of lead lines in the first group and the number of lead lines in the second group approximately equals the number of lead lines connected to one end of the plurality of sensor bars.

8. The capacitive touch sensor of claim 1, wherein the pair of lead lines for any one sensor bar have approximately equal electrical properties.

9. A capacitive touch sensor for use proximate to a surface of a device, comprising:

a plurality of sensor bars arranged in a single direction, each sensor bar comprising a first end and a second end; and

a plurality of pairs of lead lines, each lead line in a pair having approximately equal electrical properties, wherein one lead line of a pair of lead lines is coupled to one of the sensor bars at its first end and the other lead line of the pair is coupled to the sensor bar at its second end, and further wherein each sensor bar of the plurality of sensor bars is coupled to a different one of the plurality of pairs of lead lines,

wherein the plurality of sensor bars are configured to be disposed on the surface of the device.

10. The capacitive touch sensor of claim 9, wherein the sensor bars are arranged substantially parallel.

11. The capacitive touch sensor of claim 10, wherein the sensor bars further comprise substantially optically transparent material.

12. The capacitive touch sensor of claim 9, wherein the sensor bars further comprise substantially optically transparent material.

13. The capacitive touch sensor of claim 9, wherein the sensor bars further comprise indium tin oxide.

14. The capacitive touch sensor of claim 9, wherein:

the plurality of sensor bars are generally disposed lengthwise in a first direction, wherein the plurality of sensor bars are bounded in that first direction by a first side and by a second side, and further wherein the first side and the second side are approximately parallel to the first direction; and

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, wherein a sum of the number of lead lines in the first group and the number of lead lines in the second group approximately equals the number of lead lines connected to one end of the plurality of sensor bars.

15. The capacitive touch sensor of claim 9, wherein the device further comprises a touch pad.

16. A system for providing a signal for use in determining the location of a touch to a surface of a device, comprising:

a capacitive touch sensor comprising;

a plurality of sensor bars, each sensor bar comprising a first end and a second end;

a plurality of pairs of lead lines, wherein one lead line of a pair of lead lines is coupled to one of the sensor bars at its first end and the other lead line of the pair is coupled to the sensor bar at its second end, and further wherein each sensor bar of the plurality of sensor bars is coupled to a different one of the plurality of pairs of lead lines; and

the capacitive touch sensor being operative to perform the following tasks;

receive an electrical signal;

create an electrical field in response to the received electrical signal;

receive a touch in proximity to at least one sensor bar; and

provide a signal representative of a modulation of the electrical field caused by the touch, wherein the modulation is a function of the location of the touch.

17. The plurality of sensor bars of claim 16, wherein the sensor bars are arranged substantially parallel.

18. The capacitive touch sensor of claim 16, wherein the sensor bars further comprise substantially optically transparent material.

19. The capacitive touch sensor of claim 16, wherein the sensor bars further comprise indium tin oxide.

20. The capacitive touch sensor of claim 16, wherein:

the plurality of sensor bars are generally disposed lengthwise in a first direction, wherein the plurality of sensor bars are bounded in that first direction by a first side and by a second side, and further wherein the first side and the second side are approximately parallel to the first direction; and

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, wherein a sum of the number of lead lines in the first group and the number of lead lines in the second group approximately equals the number of lead lines connected to one end of the plurality of sensor bars.

21. The system of claim 16, wherein the device further comprises a touch pad.

22. A method for providing a capacitive touch sensor having symmetrical electrical properties for use proximate to a surface of a device, comprising:

providing a plurality of sensor bars arranged substantially parallel, each sensor bar comprising a first end and a second end;

providing a pair of lead lines for each sensor bar; and

coupling one lead line of a pair of lead lines to one of the sensor bars at its first end and the other lead line of the pair to the sensor bar at its second end, and further wherein each sensor bar of the plurality of sensor bars is coupled to a different one of the plurality of pairs of lead lines.

23. The method of claim 22, wherein the sensor bars further comprise substantially optically transparent material.

24. The method of claim 22, wherein the sensor bars further comprise indium tin oxide.

25. The method of claim 22, wherein:

the plurality of sensor bars are generally disposed lengthwise in a first direction, wherein the plurality of sensor bars are bounded in that first direction by a first side and by a second side, and further wherein the first side and the second side are approximately parallel to the first direction; and

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, wherein a sum of the number of lead lines in the first group and the number of lead lines in the second group approximately equals the number of lead lines connected to one end of the plurality of sensor bars.

26. A capacitive touch sensor for use proximate to a surface of a device, comprising:

a plurality of sensor bars being generally disposed lengthwise in a first direction, wherein the plurality of sensor bars are bounded in that first direction by a first side and by a second side, and further wherein the first side and the second side are approximately parallel to the first direction; and

a plurality of lead lines coupled at two ends of the sensor bars such that 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, wherein a sum of the number of lead lines in the first group and the number of lead lines in the second group approximately equals the number of lead lines connected to one end of the plurality of sensor bars.

27. The capacitive touch sensor of claim 26, wherein the device further comprises a touch pad.

28. A touch-sensitive display device, comprising:

a touch sensor including a plurality of discretely addressed sensor bars, the touch sensor being 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

a controller configured to receive signals generated by the touch sensor and to identify locations of at least two simultaneously occurring touches, wherein a first touch occurs in a first one of the plurality of input areas and a second touch occurs in a second one of the plurality of input areas.

29. The touch-sensitive display device of claim 28, wherein the discretely addressed sensor bars are each connected to a different pair of lead lines.

30. The touch-sensitive display device of claim 28, wherein the signals generated by the touch sensor are created in response to a touch implement being capacitively coupled to one or more of the sensor bars.

31. The touch-sensitive display device of claim 30, wherein the touch sensor comprises a Near Field Imaging touch sensor device.

32. The touch-sensitive display device of claim 28, wherein at least two of the plurality of input areas comprises a playing area associated with an entertainment activity.

33. The touch-sensitive display device of claim 32, wherein the entertainment activity comprises an electronically performed game.

34. The touch-sensitive display device of claim 33, wherein each of the playing areas is arranged side-by-side.