Active stylus for use with touch controller architecture

• US 10,067,580 B2
• Filed: 07/16/2014
• Issued: 09/04/2018
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Shahparnia, Shahrooz
• Primary Examiner(s): Rayan, Mihir K
• Application Number:
  US14/333,461
• Publication Number:
  US 20150035769A1
• Time in Patent Office: 1,511 Days
• 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 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/044 by capacitive means
• 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A touch controller that can configure touch circuitry according to a scan plan, which can define a sequence of scan events to be performed on a touch panel is disclosed. The touch controller can include a configurable transmit section to generate stimulation signals to drive the panel, a configurable receive section to receive and process touch signals from the panel, and a configurable memory to store the touch signals. The touch controller can also include a programmable scan engine to configure the transmit section, the receive section, and the memory according to the scan plan. The touch controller advantageously provides more robust and flexible touch circuitry to handle various types of touch events at the panel. An active stylus that can generate stimulation signals that can be detected by the touch controller during various touch events at the panel is also disclosed.

Claims

1. An active stylus, comprising:

one or more electrodes at a distal end of the stylus;

control circuitry coupled to the one or more electrodes capable of generating one or more stimulation signals; and

wireless communication circuitry coupled to the control circuitry capable of receiving information from a peripheral device, the received information including clock information and a scan plan, the scan plan including information about a plurality of scan events of the peripheral device, and wherein the control circuitry is further capable of generating the one or more stimulation signals during a plurality of stylus scan events of the peripheral device based on the clock information and the scan plan.

2. The stylus of claim 1, wherein the control circuitry is capable of generating the one or more stimulation signals at a first frequency and at a second frequency.

3. The stylus of claim 2, wherein the signals generated at the first frequency and the second frequency are generated simultaneously.

4. The stylus of claim 1, wherein the received information includes one or more stimulation frequencies, and wherein the one or more stimulation signals generated by the control circuitry are generated at the one or more stimulation frequencies received from the peripheral device.

5. The stylus of claim 4, wherein the one or more stimulation frequencies correspond to one or more low noise frequencies determined at the peripheral device.

6. The stylus of claim 1, further comprising:

a force sensor at the tip of the stylus configured to detect an amount of force at the tip of the stylus.

7. The stylus of claim 6, wherein the wireless communication circuitry is capable of transmitting the amount of force to the peripheral device.

8. The stylus of claim 1, wherein the one or more stimulation signals are generated only during a stylus scan event.

9. The stylus of claim 1, further comprising:

an internal clock coupled to at least one of the control circuitry or wireless communication circuitry, wherein the internal clock is capable of being synchronized with the peripheral device based the received clock information.

10. The stylus of claim 1, wherein the wireless communication circuitry is capable of being synchronized with the peripheral device such that the wireless communication circuitry transmits and receives information at predetermined times.

11. A method for operating an active stylus capable of stimulating a touch sensitive device, the method comprising:

receiving information from the touch sensitive device via wireless communication circuitry in the stylus, the received information including clock information and a scan plan, the scan plan including information about a plurality of scan events of the touch sensitive device;

generating, at control circuitry in the stylus, one or more stimulation signals during a plurality of stylus scan events of the touch sensitive device based on the received information including the clock information and the scan plan; and

applying the one or more stimulation signals to one or more electrodes at a distal end of the stylus.

12. The method of claim 11, wherein the one or more stimulation signals include signals at a first frequency and at a second frequency.

13. The method of claim 12, wherein the one or more stimulation signals at the first frequency and the second frequency are generated simultaneously.

14. The method of claim 11, wherein the received information includes one or more stimulation frequencies, and wherein the one or more stimulation signals generated by the control circuitry are generated at the one or more stimulation frequencies received from the touch sensitive device.

15. The method of claim 14, wherein the one or more stimulation frequencies correspond to one or more low noise frequencies determined at the touch sensitive device.

16. The method of claim 11, further comprising:

detecting, via a force sensor, an amount of force at the tip of the stylus.

17. The method of claim 16, further comprising:

transmitting, via the wireless communication circuitry, the amount of force to the touch sensitive device.

18. The method of claim 11, wherein the one or more stimulation signals are only generated during a stylus scan event.

19. The method of claim 11, further comprising:

synchronizing a clock within the stylus based on the received clock information.

20. The method of claim 11, wherein the wireless communication circuitry is synchronized so as to transmit and receive information at predetermined times.

21. A non-transitory computer readable storage medium having stored therein instructions, which when executed by an active stylus capable of stimulating a touch sensitive device, causes the stylus to perform a method comprising:

receiving information from the touch sensitive device via wireless communication circuitry in the stylus, the received information including clock information and a scan plan, the scan plan including information about a plurality of scan events of the touch sensitive device;

generating, at control circuitry in the stylus, one or more stimulation signals during a plurality of stylus scan events of the touch sensitive device based on the received information including the clock information and the scan plan; and

applying the one or more stimulation signals to one or more electrodes at a distal end of the stylus.

22. The non-transitory computer readable storage medium of claim 21, wherein the received information includes one or more stimulation frequencies, and wherein the one or more stimulation signals include simultaneously generated signals at a first frequency and at a second frequency selected from the one or more received stimulation frequencies.

23. The non-transitory computer readable storage medium of claim 21, wherein the one or more stimulation signals are only generated during a stylus scan event.

24. The non-transitory computer readable storage medium of claim 21, the instructions, when executed by an active stylus, causes synchronization of a clock within the stylus based on the received clock information.

25. An active stylus, comprising:

one or more electrodes at a distal end of the stylus;

wireless communication circuitry capable of receiving information from a touch sensitive device; and

control circuitry coupled to the one or more electrodes and coupled to the wireless communication circuitry, the control circuitry capable of;

receiving the information from the touch sensitive device during a first time interval;

generating a first set of one or more stimulation signals during a second time interval based on the information received during the first time interval; and

generating a second set of one or more stimulation signals during a third time interval based on the information received during the first time interval without receiving additional information from the touch sensitive device between the first time interval and the third time interval, wherein the second time interval and third time interval are discontinuous and correspond to separate, identical stylus scan events of the touch sensitive device, and the third time interval occurs after the second time interval.

26. The active stylus of claim 25, wherein the received information includes clock information and information about a plurality of scan events of the touch sensitive device;

wherein the second time interval is determined based on the clock information and the information about the plurality of scan events of the touch sensitive device, wherein the second time interval corresponds to a first stylus scan event of the plurality of scan events; and

wherein the third time interval is determined based on the clock information and the information about the plurality of scan events of the touch sensitive device, wherein the third time interval corresponds to a second stylus scan event of the plurality of scan events.

27. The active stylus of claim 25, wherein the received information includes a plurality of stylus stimulation frequencies corresponding to low noise frequencies determined at the touch sensitive device;

wherein the control circuitry is further capable of generating the first set of the one or more stimulation signals including simultaneously generated first signals at a first frequency and second signals at a second frequency, the first frequency and second frequency selected based on the plurality of stylus stimulation frequencies received from the touch sensitive device; and

wherein the control circuitry is further capable of generating the second set of the one or more stimulation signals including the simultaneously generated first signals at the first frequency and second signals at the second frequency.