POSITION-BASED STYLUS COMMUNICATION

• US 20170344174A1
• Filed: 05/31/2016
• Published: 11/30/2017
• Est. Priority Date: 05/31/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: PANT, Vivek, MALKIN, Moshe, SHAHPARNIA, Shahrooz
• Granted Patent: US 10,474,277 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/03545 Pens or stylus
• 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 3/0441 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
• 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

Abstract

Position-based sensing methods and systems can be used to transmit data from an input device to a touch-sensitive device. For example, the touch sensing system may perform one or more coarse input device sub-scans to determine a coarse location of the input device. The coarse location can be used to select one or more touch sensors (or sensor channels) to sample for decoding data encoded in the stimulation signals from the input device. During one or more fine input device sub-scans, the touch sensing system can determine a fine location of the input device and decode the data from the input device sampled from the selected touch sensors (or sensor channels).

Claims

1. A touch-sensitive device, comprising:

a plurality of sense channels configured to receive signals from an input device at a plurality of touch sensors;

a plurality of digital signal processors coupled to outputs of the plurality of sense channels, wherein the plurality of digital signal processors includes a plurality of first demodulators configured to demodulate the received signals;

a position estimation processor configured to estimate a location of the input device based on a first plurality of received signals processed by the plurality of digital signal processors, and configured to select a subset of the plurality of sense channels coupled to one or more touch sensors proximate to the input device based on the estimated location of the input device; and

one or more correlators couplable to the selected subset of the plurality of sense channels, wherein the one or more correlators comprise a plurality of second demodulators, the second demodulators configured to demodulate a second plurality of received signals from the selected subset of the plurality of sense channels, the one or more correlators configured to determine frequency content of the demodulated signals.

2. The touch-sensitive device of claim 1, further comprising one or more multiplexers configured to:

receive a signal indicative of the selected subset of the plurality of sense channels from the position estimation processor; and

couple the selected subset of the plurality of sense channels to the one or more correlators.

3. The touch-sensitive device of claim 1, wherein a correlator of the plurality of correlators further comprises an adder coupled to a plurality of outputs of the second demodulators, and the correlator is configured to determine the frequency content of an output of the adder.

4. The touch-sensitive device of claim 1, wherein the first plurality of received signals are received while the touch-sensitive device is configured in a first configuration, the first configuration including coupling two or more touch sensors of the plurality of touch sensors to each sense channel.

5. The touch-sensitive device of claim 1, wherein the second plurality of received signals are received while the touch-sensitive device is configured in a second configuration, the second configuration including coupling one touch sensor of the plurality of touch sensors to each sense channel.

6. A method for decoding data transmitted by an input device, the method comprising:

receiving signals from the input device;

estimating a location of the input device relative to a touch sensitive surface based on a first plurality of received signals;

selecting one or more sense channels coupled to the touch sensitive surface based on the estimated location of the input device, wherein the one or more selected sense channels sense touch sensors of the touch sensitive surface proximate to the input device; and

decoding encoded data from a second plurality of signals received at the selected one or more sense channels.

7. The method of claim 6, further comprising:

demodulating the second plurality of signals with a plurality of demodulators.

8. The method of claim 7, further comprising:

determining frequency content of the demodulated second plurality of signals.

9. The method of claim 6, further comprising:

receiving the first plurality of received signals during a first operation, the first operation comprising coupling two or more touch sensors of the touch sensitive surface to each sense channel.

10. The method of claim 6, further comprising:

receiving the second plurality of received signals during a second operation, the second operation comprising coupling one touch sensor of the touch sensitive surface to each sense channel.

11. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device including one or more processors, causes the electronic device to perform a method comprising:

receiving signals from an input device;

estimating a location of the input device relative to a touch sensitive surface based on a first plurality of received signals;

selecting one or more sense channels coupled to the touch sensitive surface based on the estimated location of the input device, wherein the one or more selected sense channels sense touch sensors of the touch sensitive surface proximate to the input device; and

decoding encoded data from a second plurality of signals received at the selected one or more sense channels.

12. The non-transitory computer readable storage medium of claim 11, wherein the method further comprises:

demodulating the second plurality of signals with a plurality of demodulators.

13. The non-transitory computer readable storage medium of claim 11, wherein the method further comprises:

determining frequency content of the demodulated second plurality of signals.

14. The non-transitory computer readable storage medium of claim 11, wherein the method further comprises:

receiving the first plurality of received signals during a first operation, the first operation comprising coupling two or more touch sensors of the touch sensitive surface to each sense channel.

15. The non-transitory computer readable storage medium of claim 11, wherein the method further comprises:

receiving the second plurality of received signals during a second operation, the second operation comprising coupling one touch sensor of the touch sensitive surface to each sense channel.

16. An apparatus comprising:

a position estimation processor configured to estimate a location of the input device based on a first plurality of signals received at a plurality of sense channels, and configured to select a subset of the plurality of sense channels coupled to one or more touch sensors proximate to the input device based on the estimated location of the input device; and

one or more correlators couplable to the selected subset of the plurality of sense channels, wherein the one or more correlators comprise a plurality of demodulators, the demodulators configured to demodulate a second plurality of signals from the selected subset of the plurality of sense channels, the one or more correlators configured to determine frequency content of the demodulated signals.

17. The apparatus of claim 16, further comprising one or more multiplexers coupled to one or more inputs of the correlators, wherein the one or more multiplexors are configured to:

receive a signal indicative of the selected subset of the plurality of sense channels from the position estimation processor; and

couple the selected subset of the plurality of sense channels to the one or more correlators.

18. The apparatus of claim 16, wherein a correlator of the plurality of correlators further comprises an adder coupled to a plurality of outputs of the demodulators.

19. The apparatus of claim 16, wherein the first plurality of signals are received while two or more touch sensors of the plurality of touch sensors are coupled to each sense channel.

20. The apparatus of claim 16, wherein the second plurality of signals are received while one touch sensor of the plurality of touch sensors is coupled to each sense channel.