Digitizer, stylus and method of synchronization therewith

• US 9,524,044 B2
• Filed: 08/12/2015
• Issued: 12/20/2016
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Zachut, Rafi
• Primary Examiner(s): Pardo, Thuy
• Application Number:
  US14/824,160
• Publication Number:
  US 20150346847A1
• Time in Patent Office: 496 Days
• Field of Search: 345/174, 345/179, 345/156, 178/18.04, 341/155
• US Class Current: 1/1
• 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 stylus comprising:

a stylus housing;

a pulse generator located in the stylus housing, the pulse generator configured to generate a burst of electromagnetic energy, wherein the burst includes a synchronization signal and a trail signal, wherein the trail signal is separate from the synchronization signal and directly trails the synchronization signal and wherein the synchronization signal and the trail signal differ from one another in at least one of frequency content and phase;

a transmitter located in the stylus housing, the transmitter configured to transmit the burst at a defined repetition rate;

a power source located in the stylus housing, the power source configured to power the transmitter and the signal generator; and

a writing tip.

2. The stylus of claim 1, wherein the burst is an AC signal.

3. The stylus of claim 2, wherein the AC signal has frequency of between 20-40 KHz.

4. The stylus of claim 2, wherein the AC signal has a frequency orthogonal to a frequency used by a digitizer system to detect finger touch, the digitizer system configured to detect input from the stylus.

5. The stylus of claim 1, wherein the repetition rate matches a refresh rate of a digitizer system configured to detect input from the stylus or an integer multiple of a refresh rate of a digitizer system configured to detect input from the stylus.

6. The stylus of claim 1, wherein the repetition rate is once every 15 msec.

7. The stylus of claim 1 comprising an encoder configured to encode the burst with information.

8. The stylus of claim 7 comprising a pressure sensor configured to detect pressure applied on the writing tip of the stylus, wherein the encoder is configured to encode the pressure detected.

9. The stylus of claim 1, wherein each of the synchronization signal and the trail signal is a pulse signal with width of between 1-2 msec.

10. The stylus of claim 1, wherein the trail signal is encoded with information.

11. The stylus of claim 10, wherein the information is related to at least one of pressure applied on the writing tip of the stylus and battery life of a battery included in the stylus.

12. The stylus of claim 1, wherein the repetition rate during hover is lower than the repetition rate during touch.

13. The stylus of claim 1, comprising a power switch configured to switch ON/OFF power.

14. The stylus of claim 1, comprising a user operated switch configured to indicate a user initiated command to switch operation of the stylus to an eraser mode or a right click mode.

15. A stylus comprising:

a stylus housing;

a pulse generator located in the stylus housing, the pulse generator configured to generate a burst of electromagnetic energy, wherein the burst is an AC signal, wherein the burst includes a synchronization signal and a trail signal, wherein the trail signal is separate from the synchronization signal and directly trails the synchronization signal and wherein the synchronization signal, and the trail signal differ from one another in at least one of frequency content and phase;

a transmitter located in the stylus housing, the pulse generator configured to transmit the burst at the defined repetition rate;

a power source located in the stylus housing, the pulse generator configured to power the transmitter and the signal generator; and

a writing tip.

16. The stylus of claim 15 comprising:

a pressure sensor configured to detect pressure applied on the writing tip of the stylus; and

an encoder configured to encode the burst with information related to the pressure.

17. The stylus of claim 15, wherein the repetition rate matches a refresh rate of a digitizer system configured to detect input from the stylus or an integer multiple of a refresh rate of a digitizer system configured to detect input from the stylus.

18. A method comprising:

generating a burst of electromagnetic energy in a stylus, wherein the burst includes a synchronization signal and a trail signal, wherein the trail signal is separate from the synchronization signal and directly trails the synchronization signal and wherein the synchronization signal and the trail signal differ from one another in at least one of frequency content and phase;

transmitting the burst at a defined repetition rate; and

powering the generation of the burst and the transmission of the burst with a power source included in the stylus.

19. The method of claim 18, wherein the burst is 1-2 msec long.

20. The method of claim 18, wherein the repetition rate matches a refresh rate of a digitizer system configured to detect input from the stylus or an integer multiple of a refresh rate of a digitizer system configured to detect input from the stylus.

21. The method of claim 18, wherein the repetition rate is once every 15 msec.

22. The method of claim 18, wherein the burst is an AC signal.

23. The method of claim 22, wherein the AC signal has frequency of between 20-40 KHz.

24. The method of claim 18 comprising encoding information related to operation of the stylus in the burst.

25. The method of claim 18, wherein only the trail signal is encoded with information.