SIMULTANEOUS SENSING ARRANGEMENT

• US 20080158167A1
• Filed: 01/03/2007
• Published: 07/03/2008
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Hotelling, Steven P., Elias, John Greer, Sakariya, Kapil Vinod
• Granted Patent: US 7,812,827 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

Multi-touch touch-sensing devices and methods are described herein. The touch sensing devices can include multiple sense points, each located at a crossing of a drive line and a sense line. In some embodiments, multiple drive lines may be simultaneously or nearly simultaneously stimulated with drive signals having unique characteristics, such as phase or frequency. A sense signal can occur on each sense line that can be related to the drive signals by an amount of touch present at sense points corresponding to the stimulated drive lines and the sense line. By using processing techniques based on the unique drive signals, an amount of touch corresponding to each sense point can be extracted from the sense signal. The touch sensing methods and devices can be incorporated into interfaces for a variety of electronic devices such as a desktop, tablet, notebook, and handheld computers, personal digital assistants, media players, and mobile telephones.

Claims

1. A method of deriving touch information from a touch sensitive surface, the touch sensitive surface comprising a plurality of sensing points, each sensing point being associated with at least one of a plurality of drive lines and at least one of a plurality of sense lines, the method comprising:

simultaneously stimulating two or more of the plurality of drive lines with drive signals, wherein a unique drive signal is applied to each of the two or more drive lines;

sensing a sense signal on at least one sense line, wherein the sense signal is related to the drive signals by touch or proximity of one or more objects to one or more sensing points associated with at least one or the two or more drive lines and the at least one sense line; and

deriving touch information from the sense signal.

2. The method of claim 1 wherein deriving touch information from the sense signal comprises:

deriving a plurality of values from the sense signal;

deriving touch information from a mathematical combination of the plurality of values.

3. The method of claim 2 wherein deriving a plurality of values from the sense signal comprises integrating the sense signal over a plurality of time periods.

4. The method of claim 1 wherein the touch information comprises an array of touch values at each sense point.

5. The method of claim 1 wherein the touch values include a capacitance measurement.

6. The method of claim 1 wherein the drive signals applied to each drive line are unique because of a predetermined phase relationship.

7. The method of claim 6 wherein the predetermined phase relationship is selected to eliminate a DC component of the sense signal.

8. The method of claim 1 wherein the drive signals applied to each drive line are unique because of a predetermined frequency relationship.

9. The method of claim 8 wherein the drive signal applied to each drive line has a unique frequency.

10. The method of claim 1 wherein the two or more of the plurality of drive lines comprises all of the drive lines of the touch sensitive surface.

11. The method of claim 1 wherein the at least one sense line comprises a drive line.

12. A touch sensing device comprising:

a touch sensitive surface having a plurality of sensing points, each sensing point being associated with one of a plurality of drive lines and one of a plurality of sense lines;

drive circuitry configured to apply drive signals simultaneously to two or more of the plurality of drive lines, wherein a unique drive signal is applied to each of the two or more drive lines;

sense circuitry configured to;

detect a sense signal in at least one sense line, the sense signal being related to the drive signals by touch or proximity of one or more objects to one or more sense points associated with the sense line; and

derive touch information for the one or more sense points from the sense signal.

13. The touch sensing device of claim 12 wherein the sense circuitry comprises at least one microcontroller.

14. The touch sensing device of claim 13 wherein the at least one microcontroller is an application specific integrated circuit (ASIC).

15. The touch sensing device of claim 13 wherein the at least one microcontroller is a digital signal processor (DSP).

16. The touch sensing device of claim 12 wherein the sense circuitry derives touch information from the sense signal by deriving a plurality of values from the sense signal and deriving touch information from a mathematical combination of the plurality of values.

17. The touch sensing device of claim 15 wherein the sense circuitry derives a plurality of values from the sense signal by integrating the sense signal over a plurality of time periods.

18. The touch sensing device of claim 12 wherein the touch sensitive surface is based on mutual capacitance.

19. The touch sensing device of claim 18 wherein the touch information comprises an array of touch values at each sense point.

20. The touch sensing device of claim 19 wherein the touch values correspond to a capacitance measurement at each sense point.

21. The touch sensing device of claim 12 wherein the drive signals applied to each drive line are unique because of a predetermined phase relationship.

22. The touch sensing device of claim 21 wherein the predetermined phase relationship is selected to eliminate a DC component of the sense signal.

23. The touch sensing device of claim 12 wherein the drive signals applied to each drive line are unique because of a predetermined frequency relationship.

24. The touch sensing device of claim 23 wherein the drive signal applied to each drive line has a unique frequency.

25. The touch sensing device of claim 12 wherein the touch sensitive surface is part of a touch screen.

26. The touch sensing device of claim 12 wherein the at least one sense line is a drive line.

27. An electronic device having as an input device a touch sensing device according to any of claims 12, 16, 17, 21, or 23.

28. The electronic device of claim 27 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

29. The electronic device of claim 27 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

30. A mobile telephone having as an input device a touch sensing device according to any of claims 12, 16, 17, 21, or 23.

31. A method of deriving touch information from a touch sensitive surface, the touch sensitive surface comprising a plurality of sensing points, each sensing point being located at a crossing of a drive line and a sense line, the method comprising:

performing a coarse scan of a first region of the touch sensitive surface to determine whether a touch is present within the first region, the first region corresponding to a first plurality of drive lines;

if a touch is present in the region, performing a fine scan of the first region; and

if a touch is not present in the region, performing a coarse scan of a second region of the touch sensitive surface, wherein the first region corresponds to a second plurality of drive lines.

32. The method of claim 31 wherein performing a coarse scan of a region comprises:

simultaneously stimulating a plurality of drive lines with drive signals;

sensing a sense signal on at least one sense line, wherein the sense signal is related to the drive signals by touch or proximity of one or more objects to one or more sensing points located at a crossing of the plurality of drive lines and the at least one sense line;

determining whether a touch is present within the region.

33. The method of claim 32 wherein determining whether a touch is present within the region comprises examining the DC content of the sense signal.

34. The method of claim 31 wherein performing a fine scan of a region comprises:

further simultaneously stimulating the plurality of drive lines with drive signals;

further sensing a sense signal on at least one sense line, wherein the sense signal is related to the further drive signals by touch or proximity of one or more objects to one or more sensing points located at a crossing of the plurality of drive lines and the at least one sense line; and

deriving fine touch information from the sense signal.

35. A method of driving a touch sensitive module having a plurality of electrically conductive lines, the method comprising:

simultaneously stimulating at least two of the plurality of lines with at least one drive signal;

sensing at least one sense signal on at least one of the plurality of lines, wherein the sense signal is related to a contact or proximity event of at least one object near the plurality of lines; and

deriving touch information from the sense signal.

36. The method of claim 35 wherein the at least one drive signal comprises a unique drive signal for each stimulated line.

37. The method of claim 36 wherein the drive signals are unique because of a predetermined phase relationship.

38. The method of claim 37 wherein the predetermined phase relationship is selected to eliminate a DC component of the sense signal.

39. The method of claim 36 wherein the drive signals are unique because of a predetermined frequency relationship.

40. The method of claim 39 wherein the drive signal applied to each drive line has a unique frequency.

41. The method of claim 35 wherein deriving touch information from the sense signal comprises:

deriving a plurality of values from the sense signal;

deriving touch information from a mathematical combination of the plurality of values.

42. The method of claim 41 wherein deriving a plurality of values from the sense signal comprises integrating the sense signal over a plurality of time periods.

43. The method of claim 35 wherein the touch information comprises an array of touch values at each sense point.

44. A touch sensing module comprising:

a touch sensitive surface having a plurality of electrically conductive lines;

drive circuitry configured to simultaneously apply at least one drive signal to two or more of the plurality of lines;

sense circuitry configured to;

detect at least one sense signal in at least one of the plurality of lines, wherein the sense signal is related to a contact or proximity event of at least one object near the plurality of lines; and

derive touch information from the sense signal.

45. The touch sensing module of claim 44 wherein the at least one drive signal comprises a unique drive signal for each stimulated line.

46. The touch sensing module of claim 45 wherein the drive signals are unique because of a predetermined phase relationship.

47. The touch sensing module of claim 46 wherein the predetermined phase relationship is selected to eliminate a DC component of the sense signal.

48. The touch sensing module of claim 45 wherein the drive signals are unique because of a predetermined frequency relationship.

49. The touch sensing module of claim 48 wherein the drive signal applied to each drive line has a unique frequency.

50. The touch sensing module of claim 44 wherein the sense circuitry comprises at least one microcontroller.

51. The touch sensing arrangement of claim 50 wherein the at least one microcontroller is an application specific integrated circuit (ASIC).

52. The touch sensing arrangement of claim 51 wherein the at least one microcontroller is a digital signal processor (DSP).

53. The touch sensing arrangement of claim 44 wherein the sense circuitry derives touch information from the sense signal by deriving a plurality of values from the sense signal and deriving touch information from a mathematical combination of the plurality of values.

54. The touch sensing arrangement of claim 53 wherein the sense circuitry derives a plurality of values from the sense signal by integrating the sense signal over a plurality of time periods.

55. The touch sensing arrangement of claim 44 wherein the touch sensitive surface is based on mutual capacitance.

56. The touch sensing arrangement of claim 44 wherein the touch sensitive surface is part of a touch screen.

57. An electronic device having as an input device a touch sensing device according to any of claims 44, 53, 56.

58. The electronic device of claim 57 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

59. The electronic device of claim 57 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

60. A mobile telephone having as an input device a touch sensing device according to any of claims 44, 53, 56.