SINGLE LAYER TRANSCAPACITIVE SENSING

• US 20110062971A1
• Filed: 07/30/2010
• Published: 03/17/2011
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Badaye, Massoud
• Granted Patent: US 8,415,959 B2
• Time in Patent Office: Days
• US Class Current: 324/686
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

First, second, and third sets of sensor electrodes are disposed in a single layer on a first surface of a substrate of a transcapacitive sensor device. Sensor electrodes of the first set are substantially parallel to a first axis and are substantially identical to one another. The second set comprises a rotated mirror symmetric version of the first set, disposed parallel to the first axis. The third set is disposed between sensor electrodes of said first set and said second set, and includes a sensor electrode comprising a rectangular shape with a long side aligned paralleling the first axis. The first and third sets of sensor electrodes are configured for providing a first capacitive coupling therebetween that varies substantially along the first axis. The second and third sets are configured for providing a second capacitive coupling therebetween that varies substantially inversely to the first capacitive coupling along the first axis.

Claims

1. A transcapacitive sensor device comprising:

a sensor substrate;

a first set of sensor electrodes disposed on a first surface of said sensor substrate, wherein individual sensor electrodes of said first set of sensor electrodes are substantially parallel to a first axis, and wherein said individual sensor electrodes of said first set of sensor electrodes are substantially identical to one another;

a second set of sensor electrodes disposed on said first surface of said sensor substrate, said second set of sensor electrodes comprising a rotated mirror symmetric version of said first set of sensor electrodes, said second set of sensor electrodes disposed parallel to said first axis; and

a third set of sensor electrodes disposed on said first surface of said sensor substrate between sensor electrodes of said first set and said second set of sensor electrodes, wherein at least one sensor electrode of said third set of sensor electrodes comprises a rectangular shape with a long side aligned parallel to said first axis,

wherein said first set and said third set of sensor electrodes are configured for providing a first capacitive coupling therebetween that varies substantially along said first axis, wherein said second set and said third set of sensor electrodes are configured for providing a second capacitive coupling therebetween that varies substantially inversely to said first capacitive coupling along said first axis, and wherein said first set, second set and third set of sensor electrodes are all disposed in a single layer.

2. The transcapacitive sensor device of claim 1, further comprising:

a fourth set of sensor electrodes disposed on said first surface in said single layer, said fourth set of sensor electrodes disposed at a laterally shifted location along said first axis from said first set of sensor electrodes and comprising a mirror symmetric copy of said first set of sensor electrodes; and

a fifth set of sensor electrodes disposed on said first surface in said single layer, said fifth set of sensor electrodes disposed at a laterally shifted location along said first axis from said second set of sensor electrodes and comprising a mirror symmetric copy of said second set of sensor electrodes.

3. The transcapacitive sensor device of claim 1, further comprising:

a processing system coupled to said first set of sensor electrodes, said second set of sensor electrodes, and said third set of sensor electrodes, wherein said processing system is configured for;

acquiring a first capacitive measurement by emitting a first electrical signal with at least one sensor electrode of said first set of sensor electrodes and receiving said first electrical signal with at least one sensor electrode of said third set of sensor electrodes;

acquiring a second capacitive measurement by emitting a second electrical signal with said second set of sensor electrodes and receiving said second electrical signal with said at least one sensor electrode of said third set of sensor electrodes; and

determining positional information related to an external input object based on said first capacitive measurement and said second capacitive measurement, wherein said positional information comprises at least a position of said input object along said first axis.

4. The transcapacitive sensor device of claim 3, further comprising:

a first common routing trace coupling a plurality of said first set of sensor electrodes to said processing system;

a second common routing trace coupling a plurality of said second set of sensor electrodes to said processing system; and

individual routing traces for independently coupling each of a plurality of sensor electrodes of said third set of sensor electrodes to said processing system.

5. The transcapacitive sensor device of claim 1, further comprising:

a processing system coupled to said first set of sensor electrodes, said second set of sensor electrodes, and said third set of sensor electrodes, wherein said processing system is configured for;

acquiring a first capacitive measurement by emitting a first electrical signal with at least one sensor electrode of said third set of sensor electrodes and receiving said first electrical signal with at least one sensor electrode of said first set of sensor electrodes;

acquiring a second capacitive measurement by emitting a second electrical signal with said at least one sensor electrode of said third set of sensor electrodes and receiving said second electrical signal with at least one sensor electrode of said second set of sensor electrodes; and

determining positional information related to an external input object based on said first capacitive measurement and said second capacitive measurement, wherein said positional information comprises at least a position of said input object along said first axis.

6. The transcapacitive sensor device of claim 1, wherein at least one sensor electrode of said first set of sensor electrodes has a varying width perpendicular to said first axis.

7. The transcapacitive sensor device of claim 1, wherein at least one sensor electrode of said first set of sensor electrodes comprises a substantially rectangular shaped body with a plurality of rectangular segments of substantially equal length protruding perpendicular to a long side of said body, where a distance between rectangular segments of said plurality of rectangular segments along said first axis varies between said rectangular segments.

8. The transcapacitive sensor device of claim 1, wherein at least one sensor electrode of said first set of sensor electrodes comprises a substantially rectangular shaped body with a plurality of rectangular segments of varying length protruding perpendicular to a long side of said body.

9. The transcapacitive sensor device of claim 1, wherein at least one sensor electrode of said third set of sensor electrodes comprises a plurality of rectangular segments protruding perpendicular to said long side, and wherein at least one of said segments is interleaved with similar segments of at least a second sensor electrode of said third set of sensor electrodes.

10. A method of capacitive sensing in a transcapacitive sensor device, wherein said transcapacitive sensor device comprises a first set of transmitter sensor electrodes, a second set of transmitter sensor electrodes, and a set of receiver sensor electrodes, said method comprising:

acquiring a first transcapacitive measurement by emitting a first electrical signal with said first set of transmitter sensor electrodes and receiving said first electrical signal with at least one receiver sensor electrode of said set of receiver sensor electrodes, wherein said first set of transmitter sensor electrodes and said set of receiver sensor electrodes are configured for providing a first capacitive coupling therebetween that varies substantially along a first axis;

acquiring a second transcapacitive measurement by emitting a second electrical signal with said second set of transmitter sensor electrodes and receiving said second electrical signal with said at least one receiver sensor electrode of said set of receiver sensor electrodes, wherein said second set of transmitter sensor electrodes and said set of receiver sensor electrodes are configured for providing a second capacitive coupling therebetween that varies substantially inversely to said first capacitive coupling along said first axis, and wherein said first set of transmitter sensor electrodes, said second set of transmitter sensor electrodes, and said set of receiver sensor electrodes are all disposed in a single layer on a first surface of a sensor substrate; and

determining positional information related to an external input object based on said first transcapacitive measurement and said second transcapacitive measurement, wherein said positional information comprises at least a position of said input object along said first axis.

11. The method as recited in claim 10 further comprising:

acquiring a third transcapacitive measurement by emitting a third electrical signal with a third set of transmitter sensor electrodes and receiving said third electrical signal with at least one receiver sensor electrode of said set of receiver sensor electrodes, wherein said third set of transmitter sensor electrodes is disposed on said first surface in said single layer at a laterally shifted location along said first axis from said first set of transmitter sensor electrodes, and wherein said third set of transmitter sensor electrodes comprises a mirror symmetric copy of said first set of transmitter sensor electrodes; and

acquiring a fourth transcapacitive measurement by emitting a fourth electrical signal with a fourth set of transmitter sensor electrodes and receiving said fourth electrical signal with at least one receiver sensor electrode of said set of receiver sensor electrodes, wherein said fourth set of transmitter sensor electrodes is disposed on said first surface in said single layer at a laterally shifted location along said first axis from said second set of transmitter sensor electrodes, and wherein said fourth set of transmitter sensor electrodes comprises a mirror symmetric copy of said second set of transmitter sensor electrodes.

12. The method as recited in claim 10 herein said acquiring a first transcapacitive measurement by emitting a first electrical signal with said first set of transmitter sensor electrodes and receiving said first electrical signal with at least one receiver sensor electrode of said set of receiver sensor electrodes comprises:

emitting said first electrical signal with said first set of transmitter sensor electrodes and receiving said first electrical signal in a time scanned fashion with at least two different receiver sensor electrodes of said set of receiver sensor electrodes; and

wherein said acquiring a second transcapacitive measurement by emitting a second electrical signal with said second set of transmitter sensor electrodes and receiving said second electrical signal with said at least one receiver sensor electrode of said set of receiver sensor electrodes comprises;

emitting said second electrical signal with said second set of transmitter sensor electrodes and receiving said second electrical signal in a time scanned fashion with at least two different receiver sensor electrodes of said set of receiver sensor electrodes.

13. A method of creating a transcapacitive sensor, said method comprising:

forming a first set of sensor electrodes on a first surface of a sensor substrate, wherein individual sensor electrodes of said first set of sensor electrodes are substantially parallel to a first axis, wherein said individual sensor electrodes of said first set of sensor electrodes are substantially identical to one another;

forming a second set of sensor electrodes on said first surface, said second set of sensor electrodes formed in a single layer with said first set of sensor electrodes, said second set of sensor electrodes comprising a rotated mirror symmetric version of said first set of sensor electrodes, and said second set of sensor electrodes formed parallel to said first axis;

forming a third set of sensor electrodes in said single layer on said first surface in an interleaved fashion between sensor electrodes of said first set of sensor electrodes and said second set of sensor electrodes, wherein any third sensor electrode comprises a rectangular shape with a long side aligned parallel to said first axis;

forming a first common routing trace for coupling a plurality of said first set of sensor electrodes to a processing system; and

forming a second common routing trace for coupling a plurality of said second set of sensor electrodes to said processing system.

14. The method as recited in claim 13, further comprising:

forming individual routing traces for independently coupling each of a plurality of sensor electrodes of said third set of sensor electrodes to said processing system.

15. The method as recited in claim 13, further comprising:

forming a fourth set of sensor electrodes disposed on said first surface in said single layer, said fourth set of sensor electrodes disposed at a laterally shifted location along said first axis from said first set of sensor electrodes and comprising a mirror symmetric copy of said first set of sensor electrodes; and

forming a fifth set of sensor electrodes disposed on said first surface in said single layer, said fifth set of sensor electrodes disposed at a laterally shifted location along said first axis from said second set of sensor electrodes and comprising a mirror symmetric copy of said second set of sensor electrodes.

16. The method as recited in claim 15, further comprising:

forming a sixth set of sensor electrodes disposed on said first surface in said single layer, said sixth set of sensor electrodes disposed at a laterally shifted location along said first axis from said third set of sensor electrodes and comprising a copy of said third set of sensor electrodes.

17. The method as recited in claim 13, wherein said forming a first set of sensor electrodes comprises:

forming said first set of sensor electrodes such that individual sensor electrodes of said first set of sensor electrodes are substantially wedge shapes elongated along said first axis and are disposed on said first surface such that a varying gap exists along said first axis between each sensor electrode of said first set of sensor electrodes and each adjacent sensor electrode of said third set of sensor electrodes.

18. The method as recited in claim 13, wherein said forming a first set of sensor electrodes comprises:

forming at least one sensor electrode of said first set of sensor electrodes as a substantially rectangular shaped body with a plurality of rectangular segments of substantially equal length protruding perpendicular to a long side of said body, where a distance along said first axis varies between said segments.

19. The method as recited in claim 13, wherein said forming a third set of sensor electrodes comprises:

forming at least one sensor electrode of said third set of sensor electrodes as a substantially rectangular shaped body with a plurality of rectangular segments protruding perpendicular to a long side of said body, and wherein at least one of said segments is interleaved with similar segments of at least a second sensor electrode of said third set of sensor electrodes.