Scan sequence generator

• US 8,232,970 B2
• Filed: 01/03/2007
• Issued: 07/31/2012
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Krah, Christoph Horst, Vu, Minh-Dieu Thi
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): NGUYEN, JENNIFER T
• Application Number:
  US11/650,046
• Publication Number:
  US 20080158180A1
• Time in Patent Office: 2,036 Days
• Field of Search: 345156-179, 178 1801- 1809
• US Class Current: 345/173
• 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 2203/04106 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 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• CPC Class Codes: G06F 3/03545 Pens or stylus
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/044 by capacitive means
• 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 3/048 Interaction techniques based on graphical user interfaces [GUI]

Abstract

A sensor panel device that can generate and use a stimulus signal having multiple different waveforms for detecting events on or near the sensor panel is disclosed. Among other things, such a stimulus signal can be used to reject environmental noise present in the device. In some embodiments, the stimulus signal has multiple waveforms having different frequencies. Logic circuitry can generate representative values from output of the different waveforms applied to one or more sensing nodes in the sensor panel device. From the representative values, a final value can be generated that represents whether an event occurred at or near the one or more sensing nodes.

Claims

1. A method of detecting events with a touch sensor panel device comprising:

applying a first stimulation signal having multiple different frequencies to a first touch sensing node of the touch sensor panel device to detect a position of an object touching the touch sensor panel device at or near the first touch sensing node;

while applying the first stimulation signal, sensing an output of the first touch sensing node for each frequency of the stimulation signal that was applied to the first touch sensing node to thereby provide multiple outputs;

determining a final result based on all or a plurality of the multiple outputs of the first touch sensing node; and

utilizing the final result to determine the position of touch, near touch or hover location on the touch sensor panel device.

2. The method of claim 1, further comprising:

applying a second stimulation signal having multiple different frequencies to a second touch sensing node of the touch sensor panel device;

sensing an output for each frequency of the second stimulation signal that was applied to the touch sensing node; and

determining a final result based on one or more of the outputs of the second stimulation signal.

3. The method of claim 2, wherein the second stimulation signal comprises a pulse train having low frequency, a pulse train having a medium frequency and a pulse train having a high frequency.

4. The method of claim 1, wherein the first stimulation signal comprises a pulse train having a low frequency, a pulse train having a medium frequency and a pulse train having a high frequency.

5. The method of claim 1, wherein the step of determining the final result comprises averaging at least two of the results.

6. The method of claim 1, wherein the step of determining the final result comprises applying a majority rules algorithm to the results.

7. The method of claim 1, wherein the step of determining the final result comprises taking a median value of the results.

8. The method of claim 1, wherein the first stimulation frequency comprises a first pulse train that is applied to the sensing node at a time t1, a second pulse train that is applied to the sensing node at a time t2 and a third pulse train that is applied to the sending node at a time t3, wherein t1 is before t2, t2 is before t3, and the time between t1 and t2 is different than the time between t2 and t3.

9. The method of claim 1, wherein determining the final result further comprises determining whether one or more of the outputs is corrupted and eliminating any corrupted output from being used when determining the final result.

10. The method of claim 1 wherein each event comprises a touching event, a near touching event or a hovering event, the sensor panel device comprises a plurality of sensing nodes arranged in first directions and wherein applying the multiple different frequencies comprising applying the frequencies to each of a plurality sensing nodes arranged in the first directions.

11. The method of claim 10 wherein applying the first stimulation signal comprises applying multiple different frequencies in ascending or descending frequency order as first, second and third frequencies applied to the plurality of sensing nodes arranged in one of the first directions and applying third, second and first frequencies to an adjacent plurality of sensing nodes arranged in the first direction.

12. The method of claim 1 wherein applying the first stimulation signal comprises applying multiple different frequencies in one of ascending or descending frequency order to a first plurality of sensing nodes arranged in a first direction, and the method further comprises applying a second stimulation signal comprising multiple different frequencies in the other of ascending or descending order to an adjacent plurality of sensing nodes arranged in the first direction.

13. A sensor panel device comprising:

an event sensitive panel having at least one sense node that provides an output signal indicative of an event or no-event condition on the panel;

output circuitry operatively connected to the at least one sense node that generates stimulus signals having multiple different frequencies, the sensing node providing multiple outputs in response to the multiple different frequencies for at least one event to detect a position of touching of the sensor panel or nearly touching the sensor panel; and

input circuitry operatively connected to the at least one sense node to receive the multiple outputs, the input circuitry configured to measure the results of any stimulus signals applied to the at least one sense node to determine a position of touch or near touch based on all or a plurality of the received multiple outputs.

14. The sensor panel device of claim 13, wherein the stimulus signals have a low, medium and high frequency.

15. The sensor panel device of claim 13, wherein the stimulus signals comprise multiple pulse trains and at least some of the pulse trains have different frequencies.

16. The sensor panel device of claim 13, further comprising:

a plurality of drive electrodes;

a plurality of sense electrodes,

the at least one sense node formed by the crossing of one of the drive electrodes with one of the sense electrodes, the sense node formed by capacitive coupling of the one of the drive electrodes and the one of the sense electrodes.

17. The sensor panel device of claim 13, wherein the input circuitry comprises at least one analog channel.

18. The sensor panel device of claim 13, further comprising a processor operatively connected to the input circuitry and configured to receive and process data provided by the input circuitry.

19. A mobile telephone incorporating the sensor panel device of claim 13.

20. The method of claim 19, wherein the generating step further comprises applying a filter to the first, second and third results.

21. The method of claim 20, wherein the filter uses an averaging algorithm.

22. The method of claim 20, wherein the filter uses a median value algorithm.

23. The method of claim 20, wherein the filter uses a majority rules algorithm.

24. A digital audio player incorporating the sensor panel device of claim 13.

25. A method of acquiring an image of a sensor panel device having a plurality of event sensors, comprising:

applying a first stimulus signal having a first frequency to a first event sensor;

receiving a first stimulus result comprising an output of the first event sensor to which the first stimulus signal was applied;

applying a second stimulus signal having a second frequency to the first event sensor;

receiving a second stimulus result comprising an output of the first event sensor to which the second stimulus signal was applied;

applying a third stimulus signal having a third frequency to the first event sensor;

receiving a third stimulus result that comprises an output of the first event sensor to which the third stimulus signal was applied;

the first, second and third frequencies different from one another and applied to the first event sensor to detect at least one of a touch, near touch, or hover event;

generating a final value of the first event sensor based on at least two of the first, second and third stimulus results.

26. The method of claim 25, wherein the first frequency is lower than the second frequency and the second frequency is lower than the third frequency.

27. The method of claim 25, further comprising offset compensating the first, second and third stimulus results.

28. An apparatus for detecting events on a sensor panel device having a sensor panel surface, the sensor panel device having a plurality of drive electrodes and a plurality of sense electrodes and capacitive sensing nodes at the intersection of the drive and sense electrodes, each capacitive sensing node formed by the intersection of a single drive line and a single sense line, the apparatus comprising:

a plurality of sensors configured to detect one or more events each sensor comprising a capacitive sensing node;

output circuitry operatively connected to the channel scan logic and the plurality of sensors, the output circuitry configured to generate stimulus signals having predetermined waveforms, at least some of the predetermined waveforms having different frequencies, each sensor providing a plurality of different outputs corresponding to the different frequencies to detect the events; and

one or more analog channels operatively connected to the plurality of sensors, the one or more analog channels configured to generate distinct values representative of events occurring at distinct locations each distinct value based on the plurality of different outputs for each sensor.

29. The apparatus of claim 28, wherein the channel scan logic circuitry, the output circuitry and the one or more analog channels form part of a touch subsystem for processing events.

30. The apparatus of claim 29, wherein the output circuitry comprises driver logic capable of driving the plurality of touch sensors with stimulus signals.

31. The apparatus of claim 28, wherein the plurality of sensors form one or more sensor rows located in distinct and non-overlapping areas.

32. The apparatus of claim 28, the plurality of sensors are arranged in rows and columns in the sensor panel, each column operatively connected to a different analog channel.

33. The apparatus of claim 28, further comprising a computing system that incorporates the apparatus, the computing system comprising:

an event subsystem operatively connected to the plurality of sensors;

an event panel processor operatively connected to the event subsystem; and

a host processor operatively connected to the event panel processor.

34. The apparatus of claim 33, further comprising a cellular telephone that incorporates the computing system.

35. The apparatus of claim 34, further comprising a digital audio player that incorporates the computing system.

36. The apparatus of claim 28 wherein the output circuitry is configured to generate stimulus signals having multiple predetermined waveforms.

37. A method for detecting events on or about a touch sensitive surface, comprising:

scanning an event sensor panel of event sensors organized in rows and columns by applying a stimulus having multiple different predetermined frequencies to one of the rows or columns, the stimulus being applied to detect a touching or near touching of an object on or over the touch sensitive surface;

during each event sensor panel scan of the rows or columns, coupling the other of the rows or columns of the event sensor panel to one or more analog channels to generate plural output values for the different frequencies representative of one or more events occurring at distinct locations at about the same time along the row or column being scanned; and

determining a final output value based on all or a plurality of the plural output values.

38. The method of claim 37, further comprising generating the one or more values representative of one or more events within an event subsystem.

39. The method of claim 37 incorporated into a computing system.

40. The method of claim 37, incorporated into a mobile telephone.

41. The method of claim 37, incorporated into a digital audio player.

42. An apparatus for sensing an event on a touch sensitive panel, comprising:

means for generating a stimulus signal comprising multiple waveforms, at least some of the waveforms having a different predetermined frequency;

means for applying the stimulus signal to a first touch sensing node of the touch sensitive panel to detect touching of the first touch sensing node, the first touch sensing node providing multiple outputs in response to the different predetermined frequencies; and

means for generating representative values of the multiple outputs of the first sensing node.

43. The apparatus of claim 42, further comprising means for generating a final value based upon all or a plurality of the representative values, the final value corresponding to whether or not an event occurred at or near the first touch sensing node.

44. A mobile telephone comprising:

an event sensitive panel having at least one sense node that provides an output signal indicative of an event or no-event condition on the panel;

output circuitry operatively connected to the at least one sense node that generates stimulus signals having multiple different frequencies, the sensing node providing multiple outputs in response to the multiple different frequencies for at least one event to detect touching of the sensor panel or nearly touching of the sensor panel; and

input circuitry operatively connected to the at least one sense node to receive the multiple outputs, the input circuitry configured to measure the results of any stimulus signals applied to the at least one sense node based on all or a plurality of the received multiple outputs.

45. The mobile of claim 44, wherein the stimulus signals have a low, medium and high frequency.

46. The mobile telephone of claim 44, wherein the stimulus signals comprise multiple pulse trains and at least some of the pulse trains have different frequencies.

47. The mobile telephone of claim 44, further comprising:

a plurality of drive electrodes,

a plurality of sense electrodes, and

the at least one sense node formed by the crossing of one of the drive electrodes with one of the sense electrodes, the sense node formed by capacitive coupling of the one drive electrode and the one sense electrode.

48. The mobile telephone of claim 44, wherein the input circuitry comprises at least one analog channel.

49. The mobile telephone of claim 44, further comprising a processor operatively connected to the input circuitry and configured to receive and process data provided by the input circuitry.

50. A digital audio player having a sensor panel having a plurality of drive electrodes and a plurality of sense electrodes and capacitive sensing nodes at the intersection of the drive and sense electrodes, each capacitive sensing node formed by the intersection of a single drive electrode and a single sense electrode, the sensor panel capable of sensing events, comprising:

a plurality of sensors configured to detect one or more events each sensor comprising a capacitive sensing node;

channel scan logic circuitry that controls stimulation signals applied to the plurality of sensors;

output circuitry operatively connected to the channel scan logic and the plurality of sensors, the output circuitry configured to generate stimulus signals having predetermined waveforms, at least some of the predetermined waveforms having different frequencies, each sensor providing a plurality of different outputs corresponding to the different frequencies to detect the events; and

one or more analog channels operatively connected to the plurality of sensors, the one or more analog channels configured to generate distinct values representative of events occurring at distinct locations each distinct value based on the plurality of different outputs for each sensor.

51. The digital audio player of claim 50, wherein each event comprises a touching, a near touch or a hovering of an object on or near the sensor panel surface.

52. The digital audio player of claim 50, wherein the channel scan logic circuitry, the output circuitry and the one or more analog channels form part of an event subsystem for processing events.

53. The digital audio player of claim 52, wherein the output circuitry comprises driver logic capable of driving the plurality of touch sensors with stimulus signals.

54. The digital audio player of claim 50, wherein the plurality of sensors form one or more sensor rows located in distinct and non-overlapping areas.

55. The digital audio player of claim 50, the plurality of sensors are arranged in rows and columns in the sensor panel, each column operatively connected to a different analog channel.

56. The digital audio player of claim 50, further comprising a computing system that incorporates the digital audio player, the computing system comprising:

an event subsystem operatively connected to the plurality of sensors;

an event panel processor operatively connected to the event subsystem; and

a host processor operatively connected to the event panel processor.

57. The digital audio player of claim 50 wherein the output circuitry is configured to generate stimulus signals having multiple predetermined waveforms.