One layer capacitive sensing apparatus having varying width sensing elements

• US 7,382,139 B2
• Filed: 06/03/2004
• Issued: 06/03/2008
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Mackey, Bob Lee
• Primary Examiner(s): Hirshfeld; Andrew H.
• Assistant Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US10/861,210
• Publication Number:
  US 20050270039A1
• Time in Patent Office: 1,461 Days
• Field of Search: 324658-662, 345/173
• US Class Current: 324/660
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

One embodiment in accordance with the invention includes a two-dimensional capacitive sensor apparatus. The two-dimensional capacitive sensor can include a first sensing element having varying width, a second sensing element having varying width, and a third sensing element having varying width. Additionally, the first sensing element, second sensing element, and third sensing element are substantially parallel to a first axis. Furthermore, each of the first sensing element, second sensing element, and third sensing element can be located such that they are not required to overlap each other to determine a first location along the first axis of a two-dimensional space. Moreover, the first sensing element, second sensing element, and third sensing element can have a cumulative width that is substantially constant.

Claims

1. A two-dimensional capacitive sensor apparatus comprising:

a first sensing element having varying width;

a second sensing element having varying width; and

a third sensing element having varying width, wherein said first sensing element, second sensing element, and third sensing element are conductive and substantially parallel to a first axis, each of said first sensing element, second sensing element, and third sensing element are located such that said first sensing element, second sensing element, and third sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, and wherein a sum of the varying widths of said first sensing element, said second sensing element, and said third sensing element is substantially constant.

2. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first sensing element, second sensing element, and third sensing element are used for determining a second location along a second axis substantially perpendicular to said first axis.

3. The two-dimensional capacitive sensor apparatus of claim 1, wherein:

said first sensing element comprises a first waveform;

said second sensing element comprises a second waveform; and

said third sensing element comprises a third waveform.

4. The two-dimensional capacitive sensor apparatus of claim 3, wherein:

said first waveform comprises a first phase;

said second waveform comprises a second phase; and

said third waveform comprises a third phase.

5. The two-dimensional capacitive sensor apparatus of claim 1, wherein:

said first sensing element comprises a sine (.theta.) waveform;

said second sensing element comprises a waveform offset from said sine (.theta.) waveform; and

said third sensing element comprises a waveform offset from said sine (.theta.) waveform.

6. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, and a third sensing element signal.

7. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first location along said first axis is determined using a trigonometric function.

8. The two-dimensional capacitive sensor apparatus of claim 1, further comprising:

a fourth sensing element utilized to determine a second location along a second axis that is substantially perpendicular to said first axis, said fourth sensing element being substantially parallel to said first axis.

9. The two-dimensional capacitive sensor apparatus of claim 1, further comprising:

a fourth sensing element having varying width;

a fifth sensing element having varying width; and

a sixth sensing element having varying width, wherein said fourth, fifth, and sixth sensing elements are substantially parallel to said first sensing element, and are located such that each does not require overlap of said first, second, third, fourth, fifth, and sixth sensing elements to determine said first location along said first axis.

10. The two-dimensional capacitive sensor apparatus of claim 9, wherein said first, second, third, fourth, fifth, and sixth sensing elements are used to determine a second position along a second axis not parallel to said first axis.

11. The two-dimensional capacitive sensor apparatus of claim 9, wherein:

said first, second, and third sensing elements each comprises a first sinusoidal waveform; and

said fourth, fifth, and sixth sensing elements each comprises a second sinusoidal waveform.

12. The two-dimensional capacitive sensor apparatus of claim 11, wherein first sinusoidal waveform has a lower frequency than said second sinusoidal waveform.

13. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first, second, and third sensing elements are utilized as part of a capacitive touch screen device.

14. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first, second, and third sensing elements are utilized as part of a capacitive touch pad device.

15. A two-dimensional capacitive sensor apparatus comprising:

a first sensing element having varying width and is conductive;

a second sensing element having varying width and is conductive and

a third sensing element having varying width and is conductive, wherein said first sensing element, second sensing element, and third sensing element are substantially parallel to a first axis and are located such that said first sensing element, second sensing element, and third sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, wherein a sum of output signals of said first sensing element, said second sensing element, and said third sensing element is substantially constant at different locations along said first sensing element, second sensing element, and third sensing element.

16. The two-dimensional capacitive sensor apparatus of claim 15, wherein said first sensing element, second sensing element, and third sensing element are used for determining a second location along a second axis, substantially perpendicular to said first axis.

17. The two-dimensional capacitive sensor apparatus of claim 15, wherein:

said first sensing element comprises a first waveform;

said second sensing element comprises a second waveform; and

said third sensing element comprises a third waveform.

18. The two-dimensional capacitive sensor apparatus of claim 15, wherein:

said first sensing element comprises a first phase;

said second sensing element comprises a second phase; and

said third sensing element comprises a third phase.

19. The two-dimensional capacitive sensor apparatus of claim 15, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, a third sensing element signal, and a trigonometric function.

20. The two-dimensional capacitive sensor apparatus of claim 15, further comprising:

a fourth sensing element utilized to determine a second location along a second axis that is non-parallel to said first axis, said fourth sensing element substantially parallel to said third sensing element.

21. A portable electronic device comprising:

a two-dimensional capacitive sensor; and

a processor coupled with said two-dimensional capacitive sensor;

wherein said two-dimensional capacitive sensor comprises;

a first sensing element having varying width;

a second sensing element having varying width; and

a third sensing element having varying width, wherein said first sensing element, second sensing element, and third sensing element are each conductive and substantially parallel to a first axis, each of said first sensing element, second sensing element, and third sensing element is located such that said first sensing element, second sensing element, and third sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, wherein a sum of the varying widths of said first sensing element, said second sensing element, and said third sensing element is substantially constant.

22. The portable electronic device of claim 21, wherein said first sensing element, second sensing element, and third sensing element are used for determining a second location along a second axis not parallel to said first axis.

23. The portable electronic device of claim 21, wherein:

said first sensing element comprises a first waveform;

said second sensing element comprises a second waveform; and

said third sensing element comprises a third waveform.

24. The portable electronic device of claim 23, wherein:

said first sensing element comprises a first phase;

said second sensing element comprises a second phase; and

said third sensing element comprises a third phase.

25. The portable electronic device of claim 21, wherein:

said first sensing element comprises a sine (.theta.) waveform;

said second sensing element comprises a sine (.theta.) waveform shifted from said sine (.theta.) waveform of said first sensing element by 2.pi./3 radians; and

said third sensing element comprises a sine (.theta.) waveform shifted from said sine (.theta.) waveform of said first sensing element by 2.pi./3 radians.

26. The portable electronic device of claim 21, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, and a third sensing element signal.

27. The portable electronic device of claim 21, wherein said first location along said first axis is determined using a trigonometric function.

28. The portable electronic device of claim 21, further comprising:

a fourth sensing element utilized to determine a second location along a second axis that is substantially perpendicular to said first axis, said fourth sensing element being substantially parallel to said first axis.

29. A capacitive sensor device comprising:

a substrate;

a first conductive trace having varying width and disposed above said substrate;

a second conductive trace having varying width and disposed above said substrate; and

a third conductive trace having varying width and disposed above said substrate, wherein said first, second, and third conductive traces are substantially parallel to a first axis and are located such that each does not require overlap of said first, second, and third conductive traces to determine a first axis location, wherein a sum of output signals of said first, said second, and said third conductive traces is substantially constant at different locations along said first, second, and third conductive traces.

30. The capacitive sensor device of claim 29, wherein:

said first conductive trace comprises a first waveform;

said second conductive trace comprises a second waveform; and

said third conductive trace comprises a third waveform.

31. The capacitive sensor device of claim 30, wherein:

said first conductive trace comprises a first phase;

said second conductive trace comprises a second phase; and

said third conductive trace comprises a third phase.

32. The capacitive sensor device of claim 31, wherein said first, second, and third conductive traces each comprises a sinusoidal waveform.

33. The capacitive sensor device of claim 29, wherein said first, second, and third conductive traces have a cumulative width that is substantially constant.

34. The capacitive sensor device of claim 29, wherein said first axis location is determined using a first conductive trace signal, a second conductive trace signal, and a third conductive trace signal.

35. The capacitive sensor device of claim 29, further comprising:

a fourth conductive trace utilized to determine a second axis location that is substantially parallel to said first axis location, said fourth conductive trace is not parallel to said first axis.

36. The capacitive sensor device of claim 29, wherein said first, second, and third conductive traces are utilized to determine a second axis location that is not parallel to said first axis.

37. A two-dimensional capacitive sensor apparatus comprising:

a first sensing element having varying width;

a second sensing element having varying width;

a third sensing element having varying width; and

a fourth sensing element having varying width, wherein said first sensing element, said second sensing element, said third sensing element and said fourth sensing element are conductive and substantially parallel to a first axis, each of said first sensing element, said second sensing element, said third sensing element and said fourth sensing element are located such that said first sensing element, said second sensing element, said third sensing element and said fourth sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, wherein said first sensing element comprises a first waveform shape;

said second sensing element comprises a second waveform shape;

said third sensing element comprises a third waveform shape and said fourth element comprises a fourth waveform shape, and wherein a sum of the varying widths of said first sensing element, said second sensing element, said third sensing element and said fourth sensing element is substantially constant, wherein said first sensing element, said second sensing element, said third sensing element and said fourth sensing element vary periodically with a period greater than the length of said first sensing element, said second sensing element, said third sensing element and said fourth sensing element, and wherein each of said first sensing element, said second sensing element, said third sensing element and said fourth sensing element has a different phase so as to produce a unique output signal along its length.

38. The two-dimensional capacitive sensor apparatus of claim 37, wherein said first sensing element, said second sensing element, said third sensing element and said fourth sensing element are used for determining a second location along a second axis substantially perpendicular to said first axis.

39. The two-dimensional capacitive sensor apparatus of claim 37, wherein said first waveform shape comprises a first phase;

said second waveform shape comprises a second phase;

said third waveform shape comprises a third phase and said fourth waveform comprises a fourth phase.

40. The two-dimensional capacitive sensor apparatus of claim 37, wherein:

said first sensing element comprises a sine (.theta.) waveform shape;

said second sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape;

said third sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape; and

said fourth sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape.

41. The two-dimensional capacitive sensor apparatus of claim 37, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, a third sensing element signal and a fourth sensing element signal.

42. The two-dimensional capacitive sensor apparatus of claim 37, wherein said first location along said first axis is determined using a trigonometric function.

43. A two-dimensional capacitive sensor apparatus comprising:

a first sensing element having varying width;

a second sensing element having varying width;

a third sensing element having varying width;

a fourth sensing element having varying width; and

a fifth sensing element having varying width, wherein said first sensing element, said second sensing element, said third sensing element, said fourth sensing element and said fifth sensing element are conductive and substantially parallel to a first axis, each of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element and said fifth sensing element are located such that said first sensing element, said second sensing element, said third sensing element, said fourth sensing element and said fifth sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, and wherein a sum of the varying widths of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element and said fifth sensing element is substantially constant.

44. The two-dimensional capacitive sensor apparatus of claim 43, wherein said first sensing element, said second sensing element, said third sensing element, said fourth sensing element and said fifth sensing element are used for determining a second location along a second axis substantially perpendicular to said first axis.

45. The two-dimensional capacitive sensor apparatus of claim 43, wherein said first sensing element comprises a first waveform;

said second sensing element comprises a second waveform;

said third sensing element comprises a third waveform, said fourth element comprises a fourth waveform, and said fifth element comprises a fifth waveform.

46. The two-dimensional capacitive sensor apparatus of claim 45, wherein said first waveform comprises a first phase;

said second waveform comprises a second phase;

said third waveform comprises a third phase, said fourth waveform comprises a fourth phase and said fifth waveform comprises a fifth phase.

47. The two-dimensional capacitive sensor apparatus of claim 43, wherein:

said first sensing element comprises a sine (.theta.) waveform;

said second sensing element comprises a waveform offset from said sine (.theta.) waveform;

said third sensing element comprises a waveform offset from said sine (.theta.) waveform;

said fourth sensing element comprises a waveform offset from said sine (.theta.) waveform and said fifth sensing element comprises a waveform offset from said sine (.theta.) waveform.

48. The two-dimensional capacitive sensor apparatus of claim 43, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, a third sensing element signal, a fourth sensing element signal and a fifth sensing element signal.

49. The two-dimensional capacitive sensor apparatus of claim 43, wherein said first location along said first axis is determined using a trigonometric function.

50. A two-dimensional capacitive sensor apparatus comprising:

a first sensing element having varying width;

a second sensing element having varying width;

a third sensing element having varying width;

a fourth sensing element having varying width;

a fifth sensing element having varying width; and

a sixth sensing element having varying width, wherein said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element and said sixth sensing element are conductive and substantially parallel to a first axis, each of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element and said sixth sensing element are located such that said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element and said sixth sensing element are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, wherein said first sensing element comprises a first waveform shape;

said second sensing element comprises a second waveform shape;

said third sensing element comprises a third waveform shape, said fourth element comprises a fourth waveform shape, said fifth element comprises a fifth waveform shape and said sixth element comprises a sixth waveform shape, and wherein a sum of the varying widths of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element and said sixth sensing element is substantially constant, wherein said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element, and said sixth sensing element vary periodically with a period greater than the length of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element, and said sixth sensing element and wherein each of said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element, and said sixth sensing element has a different phase so as to produce a unique output signal along its length.

51. The two-dimensional capacitive sensor apparatus of claim 50, wherein said first sensing element, said second sensing element, said third sensing element, said fourth sensing element, said fifth sensing element and said sixth sensing element are used for determining a second location along a second axis substantially perpendicular to said first axis.

52. The two-dimensional capacitive sensor apparatus of claim 50, wherein said first waveform shape comprises a first phase;

said second waveform shape comprises a second phase;

said third waveform shape comprises a third phase, said fourth waveform shape comprises a fourth phase, said fifth waveform shape comprises a fifth phase and said sixth waveform shape comprises a sixth phase.

53. The two-dimensional capacitive sensor apparatus of claim 50, wherein:

said first sensing element comprises a sine (.theta.) waveform shape;

said second sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape;

said third sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape;

said fourth sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape, said fifth sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape and said sixth sensing element comprises a waveform shape offset from said sine (.theta.) waveform shape.

54. The two-dimensional capacitive sensor apparatus of claim 50, wherein said first location along said first axis is determined using a first sensing element signal, a second sensing element signal, a third sensing element signal, a fourth sensing element signal a fifth sensing element signal and a sixth sensing element signal.

55. The two-dimensional capacitive sensor apparatus of claim 50, wherein said first location along said first axis is determined using a trigonometric function.

56. A two-dimensional capacitive sensor apparatus comprising:

n sensing elements, wherein each of said n sensing elements has a varying width and wherein n is an integer is larger than 2, wherein said n sensing elements are conductive and substantially parallel to a first axis, each of said n sensing elements are located such that said n sensing elements are not required to overlap each other to determine a first location along said first axis of a two-dimensional space, wherein said n sensing elements comprise n waveform shapes and wherein a sum of the varying widths of said n sensing elements is substantially constant, wherein said n sensing elements vary periodically with a period greater than the length of said n sensing elements, and wherein each of said n sensing elements has a different phase so as to produce a unique output signal along its length.

57. The two-dimensional capacitive sensor apparatus of claim 56, wherein said n sensing elements are used for determining a second location along a second axis substantially perpendicular to said first axis.

58. The two-dimensional capacitive sensor apparatus of claim 56, wherein said n waveform shapes comprise n phases.

59. The two-dimensional capacitive sensor apparatus of claim 56, wherein:

said n sensing elements comprises a sine (.theta.) waveform shape and n-1 waveform shapes offset from said sine (.theta.) waveform shape.

60. The two-dimensional capacitive sensor apparatus of claim 56, wherein said first location along said first axis is determined using n sensing element signals.

61. The two-dimensional capacitive sensor apparatus of claim 56, wherein said first location along said first axis is determined using a trigonometric function.