STYLUS PEN WITH DYNAMIC PROTOCOL SELECTION FOR COMMUNICATION WITH A DIGITIZER

• US 20170097695A1
• Filed: 10/02/2015
• Published: 04/06/2017
• Est. Priority Date: 10/02/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Lee, Woo Suk, Ribeiro, Flavio Protasio, Bathiche, Steven
• Granted Patent: US 10,671,190 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• 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 3/0441 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

Abstract

A stylus pen is disclosed that can detect touch signals from a digitizer and dynamically determine which digitizer (e.g., make/model) generated the touch signals. The stylus pen can then switch to one of a plurality of candidate protocols, without interaction from the user, so as to communicate with the digitizer. The digitizer need not explicitly communicate what protocol it supports to the stylus pen. Rather, the stylus pen analyzes the digitizer waveforms and compares the waveforms to known signatures to determine which digitizer is being used. The stylus pen can then dynamically set a protocol used to communicate with the digitizer that matches the protocol expected by the digitizer.

Claims

1. A method for communicating between a stylus pen and a digitizer, comprising:

detecting, in the stylus pen, touch signals generated by the digitizer;

analyzing the touch signals to determine which of multiple protocols to use for communication with the digitizer;

based on the analyzing, selecting one of the multiple protocols; and

transmitting signals from the stylus pen using the selected protocol.

2. The method of claim 1, wherein the analyzing of the touch signals includes performing a correlation between the detected touch signals and signatures stored within the stylus pen, the signatures being associated with different digitizer models.

3. The method of claim 1, wherein the analyzing of the touch signals includes performing frequency analysis on the touch signals and comparing the frequency analysis to stored characteristics of different digitizer models to determine which model is associated with the touch signals.

4. The method of claim 1, wherein the transmitting of the signals from the stylus pen includes transmitting pressure data indicating a pressure measurement associated with a contact of the stylus pen with a screen of the digitizer.

5. The method of claim 1, wherein the transmitting of the signals from the stylus pen includes selecting one of a plurality of transmission circuits located on the stylus pen and transmitting data from the stylus pen over the selected transmission circuit using the selected protocol.

6. The method of claim 5, wherein the transmitting of the signals further includes configuring a state machine associated with the selected protocol.

7. The method of claim 6, further including generating waveforms associated with the selected protocol using the state machine.

8. The method of claim 1, further including identifying the digitizer based on the analyzing and, based upon a model of the digitizer, enabling electrical components on the stylus pen that are supported by the digitizer.

9. A device, comprising:

a receiver in a stylus pen adapted to receive touch signals from a digitizer;

a processor coupled to the receiver, the processor configured to analyze the touch signals to determine which of a plurality of digitizers generated the received touch signals;

a memory coupled to the processor, the memory for storing signatures of the plurality of digitizers; and

a plurality of transmit circuits coupled to the processor, the transmit circuits being individually selectable by the processor based on which of the plurality of digitizers generated the received touch signals.

10. The device of claim 9, further including a correlation engine coupled to the processor and the memory configured to correlate the touch signals received from the digitizer and the stored signatures in the memory.

11. The device of claim 9, further including first and second comparators coupled to receive the touch signals from the receiver and coupled to a timer circuit, the first comparator for starting the timer circuit upon a rising edge of one of the touch signals, and the second comparator for stopping the timer circuit at a top of the rising edge, the processor coupled to the timer circuit and configured to receive a rise time from the timer circuit and to compare the rise time to signature rise times stored in the memory.

12. The device of claim 9, further including a Fast Fourier Transform engine coupled to receive the touch signals and perform frequency analysis on the touch signals.

13. The device of claim 9, wherein the processor is configured to enable a stylus sensor compatible with the digitizer based upon a determination by the processor of which of the plurality of digitizers is associated with the touch signals.

14. The device of claim 9, further including a pulse-train characterizer coupled to the receiver and to the processor, the pulse-train characterizer configured to measure one or more of the following:

a pulse period between pulses, a pulse width, a pulse train duration, or a number of pulses in a pulse train.

15. A stylus pen, comprising:

a receiver configured to receive digitizer touch signals from a digitizer; and

signal processing circuitry configured to analyze the touch signals and to determine which of a plurality of digitizers transmitted the touch signals;

wherein the stylus pen is configured to select a transmission protocol from amongst a plurality of candidate transmission protocols to communicate with the digitizer based on the determination of the signal processing circuitry as to which of the plurality of digitizers transmitted the touch signals.

16. The stylus pen of claim 15, wherein the signal processing circuitry includes a processor, and further including a memory within the stylus pen configured to store signature data for each of the plurality of digitizers.

17. The stylus pen of claim 15, wherein the signal processing circuitry includes a processor and further including a plurality of transmit circuits coupled to the processor, the processor configured to enable one of the plurality of transmit circuits associated with the digitizer.

18. The stylus pen of claim 15, further including a memory coupled to the signal processing circuitry for storing a plurality of signatures associated with the touch signals from the plurality of digitizers.

19. The stylus pen of claim 18, further including a correlation engine coupled to the signal processing circuitry, the correlation engine for matching the touch signals to one of the plurality of signatures in the memory.

20. The stylus pen of claim 15, wherein the selected transmission protocol is controlled by a state machine.