Single-layer touch sensors

• US 8,456,443 B2
• Filed: 07/24/2009
• Issued: 06/04/2013
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Bulea, Mihai M., Worfolk, Patrick
• Primary Examiner(s): SHENG, TOM V
• Application Number:
  US12/508,920
• Publication Number:
  US 20110017523A1
• Time in Patent Office: 1,411 Days
• Field of Search: 345/173, 345/174, 178/18.06, 178/19.03, 715/864, 463/37, 463/38
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A two-dimensional capacitive sensor device comprises first, second, and third sensor electrodes. The first sensor electrode has a varying width along a first direction, a maximum width at a first edge along the first direction, and a minimum width at a second edge along the first direction. The second sensor electrode has a varying width along the first direction and substantially identical widths at the first edge and second edge. The third sensor electrode has a varying width along the first direction, a minimum width at the first edge, and a maximum width at the second edge. The first, second, and third sensor electrodes have substantially equal surface area and are arranged in a first sensor cell with the second disposed between the first and third sensor electrodes. The two-dimensional capacitive sensor device comprises a plurality of sensor cells disposed in a repeated fashion in a single layer.

Claims

1. A two-dimensional capacitive sensor device comprising:

a first sensor electrode having a varying width along a first direction, a maximum width at a first edge along said first direction, and a minimum width at a second edge along said first direction;

a second sensor electrode having a varying width along said first direction and substantially identical widths at said first edge and at said second edge;

a third sensor electrode having a varying width along said first direction, a minimum width at said first edge, and a maximum width at said second edge;

wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in a first sensor cell;

wherein said second sensor electrode is disposed between said first sensor electrode and said third sensor electrode in the arrangement of said first sensor cell;

wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode have substantially equal surface area; and

wherein said two-dimensional capacitive sensor device comprises a plurality of sensor cells disposed in a repeated fashion in a single layer.

2. The two-dimensional capacitive sensor device of claim 1, wherein a boundary between said first sensor electrode and said second sensor electrode is substantially defined by the equation

3. The two-dimensional capacitive sensor device of claim 1, wherein a maximum or minimum width of a middle sensor electrode of said first sensor electrode, second sensor electrode, and third sensor electrode is located substantially halfway along said middle electrode, in said first direction.

4. A two-dimensional capacitive sensor device comprising:

a first sensor electrode having at least four linear sides and a varying width along a first direction;

a second sensor electrode having at least four linear sides and a varying width along said first direction; and

a third sensor electrode having at least four linear sides and a varying width along said first direction, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in a first sensor cell;

wherein said two-dimensional capacitive sensor device comprises a plurality of sensor cells disposed in a repeated fashion in a single layer, wherein a middle sensor electrode of said first, second, and third sensor electrodes comprises a parallelogram shape, and wherein each of said first sensor electrode, second sensor electrode, and third sensor electrode are located such that said first sensor electrode, second sensor electrode, and third sensor electrode are not required to overlap each other to determine a first location along a first axis of a two-dimensional space and a second location along a second axis, wherein said second axis is substantially non-parallel to said first axis.

5. The two-dimensional capacitive sensor device of claim 4, wherein said plurality of sensor cells includes a second sensor cell comprising a reflected arrangement of said first sensor cell.

6. The two-dimensional capacitive sensor device of claim 4, wherein said first sensor cell comprises a polygonal shape.

7. The two-dimensional capacitive sensor device of claim 4, wherein each of said first sensor electrode, said second sensor electrode, and said third sensor electrode comprises a polygonal shape.

8. The two-dimensional capacitive sensor device of claim 4, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode have substantially equal surface area.

9. The two-dimensional capacitive sensor device of claim 4, wherein a maximum or minimum width of a middle sensor electrode of said first sensor electrode, second sensor electrode, and third sensor electrode is located substantially halfway along said middle electrode, in said first direction.

10. The two-dimensional capacitive sensor device of claim 4, wherein all connections between sensing circuitry and sensor electrodes of said plurality of said sensor cells are disposed on a single side of said two-dimensional capacitive sensor.

11. The two-dimensional capacitive sensor device of claim 4, wherein a sum of said varying widths of said first sensor electrode, said second sensor electrode, and said third sensor electrode is substantially constant along said first direction.

12. The two-dimensional capacitive sensor device of claim 4, wherein two identical sensor electrodes within separate sensor cells, of said plurality of sensor cells, are coupled with the same sensor conductor.

13. The two-dimensional capacitive sensor device of claim 4, wherein two identical sensor electrodes within separate sensor cells, of said plurality of sensor cells, are coupled with different sensor conductors.

14. A two-dimensional capacitive sensor device comprising:

a first sensor cell, said first sensor cell comprising;

a first sensor electrode having at least four linear sides;

a second sensor electrode having at least four linear sides; and

a third sensor electrode having at least four linear sides, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in said first sensor cell such that said first sensor cell has 180 degree rotational symmetry about a midpoint of said first sensor cell, and wherein a middle sensor electrode of said first, second, and third sensor electrodes comprises a parallelogram shape.

15. The two-dimensional capacitive sensor device of claim 14, wherein said two-dimensional capacitive sensor device comprises a plurality of sensor cells disposed in a repeated fashion in a single layer.

16. The two-dimensional capacitive sensor device of claim 15, wherein said plurality of sensor cells includes a second sensor cell comprising a reflected arrangement of said first sensor cell.

17. The two-dimensional capacitive sensor device of claim 15, wherein all connections between sensing circuitry and sensor electrodes of said plurality of said sensor cells are disposed on a single side of said two-dimensional capacitive sensor device.

18. The two-dimensional capacitive sensor device of claim 14, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode have substantially equal surface area.

19. The two-dimensional capacitive sensor device of claim 14, wherein each of said first sensor electrode, second sensor electrode, and third sensor electrode are located such that said first sensor electrode, second sensor electrode, and third sensor electrode are not required to overlap each other to determine a first location along a first axis of a two-dimensional space and a second location along a second axis, wherein said second axis is substantially non-parallel to said first axis.

20. A method for creating a sensor array of a two-dimensional capacitive sensor device, said method comprising:

forming on a sensor substrate a first sensor electrode having at least four linear sides and a varying width along a first direction;

forming on said sensor substrate a second sensor electrode having at least four linear sides and a varying width along said first direction; and

forming on said sensor substrate a third sensor electrode having at least four linear sides and a varying width along said first direction, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in a first sensor cell of said sensor array, wherein a middle sensor electrode of said first, second, and third sensor electrodes comprises a parallelogram shape, and wherein each of said first sensor electrode, second sensor electrode, and third sensor electrode are located such that said first sensor electrode, second sensor electrode, and third sensor electrode are not required to overlap each other to determine a first location along a first axis of a two-dimensional space and a second location along a second axis, wherein said second axis is substantially non-parallel to said first axis.

21. The method as recited in claim 20, further comprising:

forming on said sensor substrate a fourth sensor electrode, said fourth sensor electrode having substantially a same shape as said first sensor electrode;

forming on said sensor substrate a fifth sensor electrode, said fifth sensor electrode having substantially a same shape as said second sensor electrode; and

forming on said sensor substrate a sixth sensor electrode, said sixth sensor electrode having substantially a same shape as said third sensor electrode, wherein said fourth sensor electrode, said fifth sensor electrode, and said sixth sensor electrode are arranged in a second sensor cell substantially identical or substantially symmetric with said first sensor cell.

22. A two-dimensional capacitive sensor device comprising:

a first sensor electrode having at least four linear sides and a varying width along a first direction;

a second sensor electrode having at least four linear sides and a varying width along said first direction; and

a third sensor electrode having at least four linear sides and a varying width along said first direction, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in a first sensor cell;

wherein said two-dimensional capacitive sensor device comprises a plurality of sensor cells disposed in a repeated fashion in a single layer, wherein a middle sensor electrode of said first, second, and third sensor electrodes comprises a parallelogram shape.

23. The two-dimensional capacitive sensor device of claim 22, wherein said plurality of sensor cells includes a second sensor cell comprising a reflected arrangement of said first sensor cell.

24. The two-dimensional capacitive sensor device of claim 22, wherein said first sensor cell comprises a polygonal shape.

25. The two-dimensional capacitive sensor device of claim 22, wherein each of said first sensor electrode, said second sensor electrode, and said third sensor electrode comprises a polygonal shape.

26. The two-dimensional capacitive sensor device of claim 22, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode have substantially equal surface area.

27. The two-dimensional capacitive sensor device of claim 22, wherein a maximum or minimum width of a middle sensor electrode of said first sensor electrode, second sensor electrode, and third sensor electrode is located substantially halfway along said middle electrode, in said first direction.

28. The two-dimensional capacitive sensor device of claim 22, wherein all connections between sensing circuitry and sensor electrodes of said plurality of said sensor cells are disposed on a single side of said two-dimensional capacitive sensor.

29. The two-dimensional capacitive sensor device of claim 22, wherein a sum of said varying widths of said first sensor electrode, said second sensor electrode, and said third sensor electrode is substantially constant along said first direction.

30. The two-dimensional capacitive sensor device of claim 22, wherein two identical sensor electrodes within separate sensor cells, of said plurality of sensor cells, are coupled with the same sensor conductor.

31. The two-dimensional capacitive sensor device of claim 22, wherein two identical sensor electrodes within separate sensor cells, of said plurality of sensor cells, are coupled with different sensor conductors.

32. A method for creating a sensor array of a two-dimensional capacitive sensor device, said method comprising:

forming on a sensor substrate a first sensor electrode having at least four linear sides and a varying width along a first direction;

forming on said sensor substrate a second sensor electrode having at least four linear sides and a varying width along said first direction; and

forming on said sensor substrate a third sensor electrode having at least four linear sides and a varying width along said first direction, wherein said first sensor electrode, said second sensor electrode, and said third sensor electrode are arranged in a first sensor cell of said sensor array, wherein a middle sensor electrode of said first, second, and third sensor electrodes comprises a parallelogram shape.

33. The method as recited in claim 32, further comprising:

forming on said sensor substrate a fourth sensor electrode, said fourth sensor electrode having substantially a same shape as said first sensor electrode;

forming on said sensor substrate a fifth sensor electrode, said fifth sensor electrode having substantially a same shape as said second sensor electrode; and

forming on said sensor substrate a sixth sensor electrode, said sixth sensor electrode having substantially a same shape as said third sensor electrode, wherein said fourth sensor electrode, said fifth sensor electrode, and said sixth sensor electrode are arranged in a second sensor cell substantially identical or substantially symmetric with said first sensor cell.