DIGITIZER, STYLUS AND METHOD OF SYNCHRONIZATION THEREWITH

• US 20100155153A1
• Filed: 12/21/2009
• Published: 06/24/2010
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: ZACHUT, Rafi
• Granted Patent: US 8,481,872 B2
• Time in Patent Office: Days
• US Class Current: 178/18.30
• 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 2203/04108 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 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/041661 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 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A method for operating a digitizer with an autonomous asynchronous stylus includes sampling outputs from a digitizer, detecting from the outputs at least one pulsed signal transmitted from an autonomous asynchronous stylus at a defined rate, determining a location of the stylus interaction with respect to the digitizer, and tracking stylus interaction with the digitizer over subsequent pulsed signals transmitted from the stylus.

Claims

1. A method for operating a digitizer with an autonomous asynchronous stylus, the method comprising:

sampling outputs from a digitizer;

detecting from the outputs at least one pulsed signal transmitted from an autonomous asynchronous stylus at a defined rate;

determining a location of the stylus interaction with respect to the digitizer;

and

tracking stylus interaction with the digitizer over subsequent pulsed signals transmitted from the stylus.

2. The method according to claim 1, comprising:

determining timing of the detected pulsed signal within a refresh cycle of the digitizer; and

synchronizing the refresh cycles of the digitizer with the timing of the received pulsed signal.

3. The method according to claim 1, comprising simultaneously detecting finger touch interaction and the stylus interaction with the digitizer.

4. The method according to claim 3, wherein the finger touch interaction is detected with at least one of a single touch detection method and a multi-touch detection method.

5. The method according to claim 4, wherein the digitizer switches from detection using a multi-touch detection method to detection using a single touch detection method in response to detection of a stylus pulsed signal.

6. The method according to claim 1, comprising simultaneously detecting conductive object interaction and stylus interaction with the digitizer.

7. The method according to claim 1, wherein the digitizer includes a grid based digitizer sensor including conductive lines arrayed along a first and second axis of the digitizer sensor.

8. The method according to claim 7, wherein timing of the detected pulsed signal is determined from output obtained from 1-4 selected conductive lines from which the pulsed signal is most strongly detected.

9. The method according to claim 7, comprising triggering at least a portion of the conductive lines with a triggering signal, and detecting finger touch interaction in response to the triggering.

10. The method according to claim 9, comprising synchronizing triggering of the conductive lines with timing of the detected pulsed signal.

11. The method according to claim 7, comprising sampling conductive lines arrayed along the second axis of the digitizer sensor in response to triggering of a conductive line arrayed along the first axis of the digitizer sensor.

12. The method according to claim 11, wherein the timing of a stylus signal is determined based on output sampled from only one of the first or second axis of the digitizer.

13. The method according to claim 2 comprising sampling a digitizer over a plurality of chunk sampling periods, wherein the plurality of chunk sampling periods cover a full transmission cycle of a stylus pulsed signal over a plurality of refresh cycles of the digitizer.

14. The method according to claim 2, wherein the synchronizing is performed while the stylus is hovering over the digitizer.

15. The method according to claim 2 comprising adjusting the synchronizing during tracking of the stylus based on timing of pulsed signals received in the subsequent refresh cycles.

16. The method according to claim 2, wherein the output is sampled over at least one chunk sampling period during each refresh cycle of the digitizer.

17. The method according to claim 16, comprising substantially synchronizing the chunk sampling periods of the digitizer with the timing of the detected pulsed signal.

18. The method according to claim 17, comprising initiating the chunk sampling periods of the refresh cycles of the digitizer at a predetermined period before the timing of the detected stylus pulsed signal within the refresh cycle of the digitizer.

19. The method according to claim 1, wherein a transmission cycle of the stylus varies for different operational modes of the stylus and wherein the digitizer is operative to detect and track the stylus pulsed signal at varying transmission cycles.

20. The method according to claim 1, wherein the pulsed signal comprises an AC burst signal of a pre-defined frequency.

21. The method according to claim 20, wherein the digitizer detects the pulsed signal of the stylus based on detection of the pre-defined frequency.

22. The method according to claim 20, wherein the detecting comprises running a DFT window tuned to the pre-defined frequency on the outputs sampled during at least one refresh cycle.

23. The method according to claim 1, comprising determining an operational state of the stylus from the detected pulsed signal.

24. The method according to claim 1, wherein the stylus transmits a train of pulsed signals transmitted in succession over a transmission cycle of the stylus and wherein the digitizer samples the train of pulsed signals over a refresh period of the digitizer.

25. The method according to claim 24, wherein at least one of the pulsed signals in the train of pulsed signal includes encoded information.

26. The method according to claim 25, wherein the encoded information is selected from the group including:

identification of the stylus, right click mode of the stylus, eraser mode of the stylus, pressure on tip of the stylus, and user selected color.

27. The method according to claim 25, comprising decoding information encoded in at least one stylus pulsed signal from the outputs.

28. A method for operating a digitizer with an autonomous asynchronous stylus, the method comprising:

receiving pulsed signals by the digitizer from the autonomous stylus;

determining a location on the digitizer from which the pulsed signal is detected; and

tracking stylus interaction with the digitizer over subsequent refresh cycles.

29. The method according to claim 28 comprising simultaneously detecting finger touch interaction and stylus interaction, wherein the stylus interaction is performed with the asynchronous stylus.

30. The method according to claim 29, wherein the finger touch interaction is detected with at least one of a single touch detection method and a multi-touch detection method.

31. A method for operating a digitizer with an autonomous asynchronous stylus, the method comprising:

receiving pulsed signals by the digitizer from the autonomous stylus, said signals including information;

determining a location on the digitizer from which the pulsed signal is detected; and

detecting finger touch interaction with the digitizer.

32. A digitizer system operated with an asynchronous stylus comprising:

a digitizer sensor that receives signals;

a stylus that transmits autonomous asynchronous signals, said signals including information on an operational state of the stylus; and

a processor in the digitizer system that determines position coordinates on the digitizer sensor and the operational state of the stylus from the received signals.

33. The digitizer according to claim 32, wherein the digitizer sensor senses finger touch interaction and wherein the processor determines position coordinates of the finger touch interaction.