TOUCH SYSTEMS AND METHODS INCLUDING REJECTION OF UNINTENTIONAL TOUCH SIGNALS

• US 20170153763A1
• Filed: 06/30/2015
• Published: 06/01/2017
• Est. Priority Date: 07/02/2014
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Vavra, Joshua D., Rebeschi, Thomas J., Cordeiro, Craig A., Tomic, Jakisa
• Granted Patent: US 10,216,330 B2
• Time in Patent Office: Days
• 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 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• 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 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A touch sensor can be used with a finger and/or a pen configured to provide a touch input to the touch sensor. Some implementations involve touch capacitive touch sensing, although many implementations are also applicable to other touch and pen technologies, such as resistive, surface acoustic wave, bending wave, touch force, electromagnetic (E-M). Discrimination between intentional touches and unintentional touches on the touch surface can be performed using first criteria. For each touch identified as an intentional touch, discrimination between a fmger touch and a pen touch can be performed using second criteria.

Claims

1-10. -10. (canceled)

11. A method of determining a touch location on a touch surface of a touch panel comprising a matrix of intersecting electrodes with nodes at intersections of the electrodes, the method comprising:

discriminating between one or more intentional touches and one or more unintentional touches on the touch surface using first criteria; and

for each touch identified as an intentional touch, discriminating between a finger touch and a pen touch using second criteria.

12. The method of claim 11, wherein the intentional touches comprise multiple temporally overlapping touches.

13. The method of claim 11, wherein discriminating between the intentional and unintentional touches using the first criteria comprises identifying a touch as an unintentional touch based on at least one of:

a size of a profile of the touch on the touch surface;

a number of peaks within the profile; and

a distance between a peak of the profile and nodes of the profile.

14. The method of claim 11, wherein discriminating between the pen touch and the finger touch using the second criteria comprises:

determining a slope of a profile of a touch on the touch surface;

identifying the touch as a finger touch if the slope is greater than a slope threshold; and

identifying the touch as a potential pen touch if the slope is less than the slope threshold.

15. The method of claim 11, wherein discriminating between the finger touch and the pen touch comprises identifying the touch as a pen touch if a distance between a touch and a profile of a previously identified intentional or unintentional touch is greater than a distance threshold.

16. The method of claim 11, wherein discriminating between the finger touch and the pen touch comprises identifying the touch as a pen touch if nodes within the predetermined radius of a profile of the touch have signal values less than an ambient threshold.

17. The method of claim 11, further comprising re-identifying the pen touch as a finger touch if the pen touch was previously identified as a finger touch.

18. The method of claim 11, wherein discriminating between the intentional and the unintentional touch comprises:

determining a profile of a touch on the touch surface; and

identifying the touch as an unintentional touch based on one or more of;

a size of the profile;

a number of peaks within the profile; and

a distance between a peak of the profile and nodes of the profile.

19. A touch sensor, comprising:

a touch panel having a touch surface and a matrix of electrodes with nodes at intersections of the electrodes; and

a touch controller configured to

discriminate between one or more intentional touches and one or more unintentional touches on the touch surface using first criteria; and

for each touch identified as an intentional touch, discriminate between a finger touch and a pen touch using second criteria.

20. The touch sensor of claim 19, wherein the intentional touches comprise multiple temporally overlapping touches.

21. The touch sensor of claim 19, wherein the controller discriminates between the intentional and unintentional touches using the first criteria by identifying a touch as an unintentional touch based on at least one of:

a size of a profile of the touch on the touch surface;

a number of peaks within the profile; and

a distance between a peak of the profile and nodes of the profile.

22. The touch sensor of claim 19, wherein the controller discriminates between the pen touch and the finger touch using the second criteria by:

determining a slope of a profile of a touch on the touch surface;

identifying the touch as a finger touch if the slope is greater than a slope threshold; and

identifying the touch as a potential pen touch if the slope is less than the slope threshold.

23. The touch sensor of claim 19, wherein the controller discriminates between the finger touch and the pen touch by identifying the touch as a pen touch if a distance between a touch and a profile of a previously identified intentional or unintentional touch is greater than a distance threshold.

24. The touch sensor of claim 19, wherein controller is configured to discriminate between the finger touch and the pen touch by identifying the touch as a pen touch if nodes within the predetermined radius of a profile of the touch have signal values less than an ambient threshold.

25. The touch sensor of claim 19, wherein the controller is configured to re-identify the pen touch as a finger touch if the pen touch was previously identified as a finger touch.

26. The touch sensor of claim 19, wherein the controller is configured to discriminate between the intentional and the unintentional touch by:

determining a profile of a touch on the touch surface; and

identifying the touch as an unintentional touch based on one or more of;

a size of the profile;

a number of peaks within the profile; and

a distance between a peak of the profile and nodes of the profile.

27. A method of operating a touch sensor, the method comprising:

determining a profile of a touch on a touch surface of the touch sensor, the touch profile bounded by an edge of connected nodes having a signal value greater than a threshold;

identifying one or more peak nodes corresponding to signal peaks within the touch profile; and

classifying the touch as an intentional touch or an unintentional touch based on the one or more peak nodes and an area or shape of the touch profile.

28. The method of claim 27, wherein classifying the touch comprises classifying the touch as an unintentional touch if the touch profile includes one peak node and the area of the profile is greater than a threshold area for a finger touch.

29. The method of claim 27, wherein classifying the touch comprises classifying the touch as unintentional if the touch profile includes multiple peak nodes and the area of the profile is greater than a threshold area for multiple touches within the touch profile.

30. The method of claim 27, wherein classifying the touch comprises classifying the touch as unintentional based on a number of peak nodes as a function of the area of the touch profile.

31. The method of claim 27, wherein classifying the touch comprises classifying the touch as unintentional if a distance between at least one non-peak node in the profile and a peak node nearest to the non-peak node exceeds a threshold distance.

32. The method of claim 27, wherein classifying the touch comprises classifying the touch based on a history over multiple scans of the touch panel of at least one of:

number of peak nodes within the touch profile,

profile area,

profile shape; and

connections between touch profile nodes over the multiple scans.

33. The method of claim 27, wherein:

classifying the touch comprises classifying the touch as unintentional during a first scan of the touch panel; and

on a next scan of the touch panel, classifying any node having a signal value above the threshold that is connected to a node of the unintentional touch of the previous scan as a node within a profile of a continuing unintentional touch.

34. The method of claim 33, further comprising:

identifying a subsequent touch that falls within the profile of the unintentional touch or the continuing unintentional touch as an intentional touch only after there has been at least one scan of the touch panel for which no nodes within the profile of the unintentional touch or the continuing unintentional touch have a signal value above the threshold value.

35. The method of claim 27, further comprising discriminating between an intentional pen touch and an intentional finger touch.

36. A touch sensor, comprising:

a touch panel having a touch surface and a matrix of electrodes with nodes at intersections of the electrodes; and

a touch controller configured to

identify a profile of a touch on the touch surface, the profile bounded by an edge of connected nodes having a signal value greater than a threshold;

identify one or more peak nodes corresponding to signal peaks within the touch profile; and

discriminate between an intentional touch and an unintentional touch based on the one or more peak nodes and an area or shape of the touch profile.

37. The touch sensor of claim 36, wherein the controller is configured to classify the touch as an unintentional touch if the touch profile includes one peak node and the area of the profile is greater than a threshold area for a finger touch.

38. The touch sensor of claim 36, wherein the controller is configured to classify the touch as unintentional if the touch profile includes multiple peak nodes and the area of the profile is greater than a threshold area for multiple touches within the touch profile.

39. The touch sensor of claim 36, wherein the controller is configured to classify the touch as unintentional based on a number of peak nodes as a function of the area of the touch profile.

40. The touch sensor of claim 36, wherein the controller is configured to classify the touch as unintentional if a distance between at least one non-peak node in the profile and a peak node nearest to the non-peak node exceeds a threshold distance.

41. The touch sensor of claim 36, wherein the controller is configured to classify the touch based on a history over multiple scans of the touch panel of at least one of:

number of peak nodes within the touch profile,

profile area,

profile shape; and

connections between touch profile nodes over the multiple scans.

42. The touch sensor of claim 36, wherein the controller is configured to:

classify the touch as unintentional during a first scan of the touch panel; and

on a next scan of the touch panel, classify any node having a signal value above the threshold that is connected to a node of the unintentional touch of the previous scan as a node within a profile of a continuing unintentional touch.

43. The touch sensor of claim 42, wherein the controller is configured to:

identify a subsequent touch that falls within the profile of the unintentional touch or the continuing unintentional touch as an intentional touch only after there has been at least one scan of the touch panel for which no nodes within the profile of the unintentional touch or the continuing unintentional touch have a signal value above the threshold value.