One layer capacitive sensing apparatus having varying width sensing elements

• US 20050270039A1
• Filed: 06/03/2004
• Published: 12/08/2005
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Mackey, Bob Lee
• Granted Patent: US 7,382,139 B2
• Time in Patent Office: Days
• 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; and

a second sensing element having varying width, wherein said first sensing element and second sensing element are conductive and form a loop, each of said first sensing element and said second sensing element is located such that said first sensing element and second sensing element are not required to overlap each other to determine an angular position of an object relative to said loop in a two-dimensional space.

2. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first sensing element and said second sensing element are used for determining a radial position of said object relative to said loop in said two-dimensional space.

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

said first sensing element comprises a first waveform; and

said second sensing element comprises a second waveform.

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

said first sensing element comprises a first phase; and

said second sensing element comprises a second phase different from said first phase.

5. The two-dimensional capacitive sensor apparatus of claim 1, wherein said first sensing element and said second sensing element each comprises a sinusoidal waveform.

6. 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 form a substantially circular pattern, 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 an angular position of an object relative to said substantially circular pattern in a two-dimensional space, wherein said first sensing element, second sensing element, and third sensing element provide a cumulative output signal that is substantially constant at different locations along said substantially circular pattern.

7. The two-dimensional capacitive sensor apparatus of claim 6, wherein said first sensing element, second sensing element, and third sensing element are used for determining a radial position of said object relative to said substantially circular pattern in said two-dimensional space.

8. The two-dimensional capacitive sensor apparatus of claim 6, 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.

9. The two-dimensional capacitive sensor apparatus of claim 8, 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.

10. The two-dimensional capacitive sensor apparatus of claim 6, wherein:

said first sensing element comprises a waveform;

said second sensing element comprises a waveform that is offset from said waveform of said first sensing element by 2π

/3 radians; and

said third sensing element comprises a waveform that is offset from said waveform of said first sensing element by 2π

/3 radians.

11. The two-dimensional capacitive sensor apparatus of claim 6, wherein said angular position is determined using a first sensing element signal, a second sensing element signal, and a third sensing element signal.

12. The two-dimensional capacitive sensor apparatus of claim 11, wherein said angular position is determined using a trigonometric function.

13. A two-dimensional capacitive sensor apparatus which does not require overlapping sensing elements comprising:

a first sensing element that is conductive;

a second sensing element that is conductive; and

a third sensing element that is conductive,

wherein the shape of said second sensing element is defined by the shape of said first sensing element and the shape of said third sensing element, wherein said first sensing element, second sensing element, and third sensing element form a loop for determining an angular location of an object relative to said loop within a two-dimensional space.

14. The two-dimensional capacitive sensor apparatus of claim 13, wherein said first sensing element, second sensing element, and third sensing element are used for determining a radial position of said object relative to said loop in said two-dimensional space.

15. The two-dimensional capacitive sensor apparatus of claim 13, 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.

16. The two-dimensional capacitive sensor apparatus of claim 13, wherein said first sensing element, said second sensing element, and third sensing element each comprises a sinusoidal waveform.

17. 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 said first sensing element, second sensing element, and third sensing element have a cumulative width that is substantially constant.

18. The two-dimensional capacitive sensor apparatus of claim 17, 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.

19. The two-dimensional capacitive sensor apparatus of claim 17, 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.

20. The two-dimensional capacitive sensor apparatus of claim 19, wherein:

said first waveform comprises a first phase;

said second waveform comprises a second phase; and

said third waveform comprises a third phase.

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

said first sensing element comprises a sine (θ

) waveform;

said second sensing element comprises a waveform offset from said sine (θ

) waveform; and

said third sensing element comprises a waveform offset from said sine (θ

) waveform.

22. The two-dimensional capacitive sensor apparatus of claim 17, 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.

23. The two-dimensional capacitive sensor apparatus of claim 17, wherein said first location along said first axis is determined using a trigonometric function.

24. The two-dimensional capacitive sensor apparatus of claim 17, 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.

25. The two-dimensional capacitive sensor apparatus of claim 17, 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.

26. The two-dimensional capacitive sensor apparatus of claim 25, 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.

27. The two-dimensional capacitive sensor apparatus of claim 25, 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.

28. The two-dimensional capacitive sensor apparatus of claim 27, wherein first sinusoidal waveform has a lower frequency than said second sinusoidal waveform.

29. The two-dimensional capacitive sensor apparatus of claim 17, wherein said first, second, and third sensing elements are utilized as part of a capacitive touch screen device.

30. The two-dimensional capacitive sensor apparatus of claim 17, wherein said first, second, and third sensing elements are utilized as part of a capacitive touch pad device.

31. 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 said first sensing element, second sensing element, and third sensing element provide a cumulative output signal that is substantially constant at different locations along said first sensing element, second sensing element, and third sensing element.

32. The two-dimensional capacitive sensor apparatus of claim 31, 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.

33. The two-dimensional capacitive sensor apparatus of claim 31, 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.

34. The two-dimensional capacitive sensor apparatus of claim 31, 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.

35. The two-dimensional capacitive sensor apparatus of claim 31, 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.

36. The two-dimensional capacitive sensor apparatus of claim 31, 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.

37. A two-dimensional capacitive sensor apparatus that does not require overlapping sensing elements comprising:

a first conductive trace including a first plurality of extensions that are substantially parallel to each other and are substantially non-parallel to a first axis of said first conductive trace, said first plurality of extensions cumulatively defines an envelope in the shape of a first waveform;

a second conductive trace including a second plurality of extensions that are substantially parallel to each other and are substantially non-parallel to said first axis of said second conductive trace, said second plurality of extensions cumulatively defines an envelope in the shape of a second waveform; and

a third conductive trace including a third plurality of extensions that are substantially parallel to each other and are substantially non-parallel to said first axis of said third conductive trace, said third plurality of extensions cumulatively defines an envelope in the shape of a third waveform,

wherein said first, second, and third conductive traces are used for determining a first location along said first axis of a two-dimensional space.

38. The two-dimensional capacitive sensor apparatus of claim 37, wherein said first plurality of extensions and said second plurality of extensions are interdigitated.

39. The two-dimensional capacitive sensor apparatus of claim 38, wherein said second plurality of extensions and said third plurality of extensions are interdigitated.

40. 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 said first sensing element, second sensing element, and third sensing element have a cumulative width that is substantially constant.

41. The portable electronic device of claim 40, 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.

42. The portable electronic device of claim 40, 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.

43. The portable electronic device of claim 42, 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.

44. The portable electronic device of claim 40, wherein:

said first sensing element comprises a sine (θ

) waveform;

said second sensing element comprises a sine (θ

) waveform shifted from said sine (θ

) waveform of said first sensing element by 2π

/3 radians; and

said third sensing element comprises a sine (θ

) waveform shifted from said sine (θ

) waveform of said first sensing element by 2π

/3 radians.

45. The portable electronic device of claim 40, 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.

46. The portable electronic device of claim 40, wherein said first location along said first axis is determined using a trigonometric function.

47. The portable electronic device of claim 40, 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.

48. 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 conductive and disposed along a loop, 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 an angular location of an object relative to said loop within a two-dimensional space, wherein said first sensing element, second sensing element, and third sensing element have a cumulative width that is substantially constant.

49. The portable electronic device of claim 48, wherein said first sensing element, said second sensing element, and third sensing element are used for determining a radial position of said object relative to said loop in said two-dimensional space.

50. The portable electronic device of claim 48, wherein said first sensing element, second sensing element, and third sensing element provide a cumulative output signal that is substantially constant at different locations along said first sensing element, second sensing element, and third sensing element.

51. The portable electronic device of claim 48, wherein:

said first sensing element comprises a waveform;

said second sensing element comprises a waveform; and

said third sensing element comprises a waveform.

52. The portable electronic device of claim 48, wherein:

said first sensing element comprises a phase;

said second sensing element comprises a phase different from said phase of said first sensing element; and

said third sensing element comprises a phase different from said phase of said first sensing element.

53. The portable electronic device of claim 48, wherein said first sensing element, said second sensing element, and said third sensing element each comprises a sinusoidal waveform.

54. 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.

55. The capacitive sensor device of claim 54, 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.

56. The capacitive sensor device of claim 55, 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.

57. The capacitive sensor device of claim 56, wherein said first, second, and third conductive traces each comprises a sinusoidal waveform.

58. The capacitive sensor device of claim 54, wherein said first, second, and third conductive traces have a cumulative width that is substantially constant.

59. The capacitive sensor device of claim 54, wherein said first axis location is determined using a first conductive trace signal, a second conductive trace signal, and a third conductive trace signal.

60. The capacitive sensor device of claim 54, further comprising:

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

61. The capacitive sensor device of claim 54, wherein said first, second, and third conductive traces are utilized to determine a second axis location that is not parallel to said first axis.

62. 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 form a curved path, 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 radial location along said curved path of a two-dimensional space, wherein said first sensing element, second sensing element, and third sensing element have a cumulative width that is substantially constant.

63. The portable electronic device of claim 62, wherein said first sensing element, said second sensing element, and third sensing element are used for determining an angular position of said object relative to said curved path in said two-dimensional space.

64. The portable electronic device of claim 62, wherein said first sensing element, second sensing element, and third sensing element provide a cumulative output signal that is substantially constant at different locations along said first sensing element, second sensing element, and third sensing element.

65. The portable electronic device of claim 62, wherein:

said first sensing element comprises a waveform;

said second sensing element comprises a waveform; and

said third sensing element comprises a waveform.

66. The portable electronic device of claim 65, wherein:

said first sensing element comprises a phase;

said second sensing element comprises a phase different from said phase of said first sensing element; and

said third sensing element comprises a phase different from said phase of said first sensing element.

67. The portable electronic device of claim 62, wherein said first sensing element, said second sensing element, and said third sensing element each comprises a sinusoidal waveform.