Scan sequence generator

• US 8,659,568 B2
• Filed: 07/19/2012
• Issued: 02/25/2014
• 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): NGUYEN, JENNIFER T
• Application Number:
  US13/553,421
• Publication Number:
  US 20120280932A1
• Time in Patent Office: 586 Days
• Field of Search: 345173-178, 178 1801- 1806
• 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 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;

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

utilizing the output to determine a result indicative of the position of touch, near touch or hover location on the touch sensor panel device; and

wherein applying the stimulation signal comprises selecting at least one of the multiple different frequencies to apply to the first sensing node of the touch sensor panel to reduce effects of a noise environment.

2. The method of claim 1, wherein the stimulation signal comprises a first and second stimulation signal each having multiple different frequencies and the method further comprising:

applying the second stimulation signal 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 second 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 applying the first stimulation signal comprises applying a first of the multiple different frequencies to all channels of the touch sensor and subsequently applying a second of the multiple different frequencies to all channels of the touch sensor.

4. The method of claim 1, wherein the stimulation signal comprises a pulse train having multiple frequencies arranged in ascending and descending order.

5. The method of claim 1, wherein applying the stimulation signal comprises applying a first and a second of the multiple different frequencies to a first channels of the touch sensor and subsequently applying the first and the second of the multiple different frequencies to a second channel of the touch sensor.

6. The method of claim 1, wherein the step of utilizing the multiple outputs to determine the result comprises one of averaging at least two results or applying a majority rules algorithm to plural results.

7. The method of claim 1, wherein the step of utilizing the multiple outputs to determine the result comprises taking a median value of multiple results.

8. The method of claim 1, wherein the 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 utilizing the output comprises determining whether one or more outputs is corrupted and eliminating any corrupted output.

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

11. The method of claim 1, wherein applying the stimulation signal comprises applying a first and a second stimulations signal, each having multiple different frequencies, the method comprises applying the multiple different frequencies of the first stimulation signal 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 the 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.

12. The method of claim 1, wherein the selecting is done by adaptively selecting.

13. The method of claim 1, wherein the event sensitive panel device comprises drive lines and sense lines and the first sensing node is defined by the crossing of one of the drive lines and one of the sense lines and applying the stimulation signal to the first touch sensing node comprises applying the first stimulation signal to the one drive line.

14. A sensor panel device comprising:

an event sensitive panel having at least one sense node;

output circuitry operatively connected to the at least one sense node that generates stimulus signals having multiple different frequencies, at least one of the multiple different frequencies selected to reduce effects of a noise environment of the sensor panel device, the at least one sense 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.

15. The sensor panel device of claim 14, wherein the stimulus signals comprises a pulse train having multiple frequencies arranged in ascending and descending order.

16. The sensor panel device of claim 14, wherein the output circuitry applies a first of the multiple different frequencies to all channels of the sensor panel device and subsequently applying a second of the multiple different frequencies to all the channels of the sensor panel device.

17. The sensor panel device of claim 14, 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.

18. The sensor panel device of claim 14, wherein the output circuitry applies a first and a second of the multiple different frequencies to a first channels of the sensor panel device and subsequently applies the first and the second of the multiple different frequencies to a second channel of the sensor panel device.

19. A mobile telephone incorporating the sensor panel device of claim 14.

20. A digital audio player incorporating the sensor panel device of claim 14.

21. The sensor panel of claim 14, wherein the at least one sense node is defined by a crossing of a drive line and a sense line, and the output circuitry is operatively connected to the drive line.

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

selecting at least a first and a second stimulus signal, at least one of the first and second stimulus signal selected to reduce effects of a noise environment of the sensor panel;

applying the first stimulus signal having a first frequency to a first event sensor of the plurality of event sensors;

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

applying the 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;

the first and second 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 at least on the first and second stimulus results.

23. The method of claim 22, wherein the first and second frequencies are arranged in ascending or descending order.

24. The method of claim 22, further comprising offset compensating at least the first and second stimulus results.

25. The method of claim 22, wherein the generating step further comprises applying a filter to at least the first and second results.

26. The method of claim 25, wherein the filter uses an averaging algorithm.

27. The method of claim 25, wherein the filter uses a median value algorithm.

28. The method of claim 25, wherein the filter uses a majority rules algorithm.

29. The method of claim 22, wherein the selecting is done by adaptively selecting.

30. 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 drive line and a 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 plurality of sensors, the output circuitry configured to generate stimulus signals having predetermined waveforms, the stimulus signals selected to reduce effects of a noise environment of the sensor panel device, 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 one or more 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.

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

32. The apparatus of claim 30, wherein the plurality of sensors form one or more sensor rows located in distinct and non-overlapping areas.

33. The apparatus of claim 30, the plurality of sensors are arranged in rows and columns in the sensor panel, each column operatively connected to a different analog channel.

34. The apparatus of claim 30, 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.

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

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

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 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, and at least one of the multiple different frequencies selected to reduce effects of a noise environment of the event sensor panel;

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 plural output 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. The method of claim 37, wherein the scanning is done by adaptively selecting the at least one of the multiple different frequencies.

43. 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 plurality of sensors, the output circuitry configured to generate stimulus signals having predetermined waveforms, the stimulus signals selected to reduce effects of previously determined noise data of the sensor panel device, 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 one or more 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.