Multiple controller communication method for active stylus data acquisition

• US 9,671,910 B2
• Filed: 10/23/2014
• Issued: 06/06/2017
• Est. Priority Date: 10/23/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: Cheong, Chee Weng, Guo, Dianbo, Zhang, Chao Chao, Dinu, Leonard, Ng, Eng Jye
• Primary Examiner(s): Mummalaneni, Nalini
• Application Number:
  US14/522,098
• Publication Number:
  US 20160117047A1
• Time in Patent Office: 957 Days
• 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 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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

An electronic device may include a first controller associated with some channels of a digitizer having channels configured to receive a signal from a stylus, and with each channel having a direction. A second controller may be associated with channels of the digitizer not associated with the first controller. The first controller may scan for the signal at each channel associated with the first controller, and based on acquisition of the signal at a given channel associated with the first controller, calculate a property of the signal. The first controller may send the calculated property and the direction of the given channel to the second controller. The first controller and the second controller may scan for the signal at each channel having the direction of the given channel, at acquisition intervals based upon the calculated property.

Claims

1. An electronic device comprising:

a first controller associated with some channels of a digitizer having channels configured to receive a signal from a stylus, each channel having a direction;

a second controller associated with channels of the digitizer not associated with the first controller;

the first controller configured to;

scan for the signal at each channel associated with the first controller,

based on acquisition of the signal at a given channel associated with the first controller, calculate a property of the signal,

determine a phase mismatch between an expected signal and the signal acquired at the given channel and an associated phase correction, and

filter noise from the signal acquired at each channel associated with the first controller, based upon the phase mismatch being greater than a threshold phase mismatch, and

send the calculated property, the phase correction, and the direction of the given channel to the second controller; and

the first controller and the second controller configured to;

scan for the signal at each channel having the direction of the given channel, at acquisition intervals based upon the calculated property, and

correct the signal acquired at each channel, using the phase correction.

2. The electronic device of claim 1, wherein the property of the signal comprises a period of the signal.

3. The electronic device of claim 1, wherein the first controller is configured to scan for the signal at each channel associated with the first controller having a direction not parallel to the direction of the given channel, at the acquisition intervals.

4. The electronic device of claim 3, wherein the second controller is configured to, based upon a failure of the first controller acquire the signal at a channel in the direction not parallel to the direction of the given channel, scan for the signal at each channel associated with the second controller, at the acquisition intervals.

5. The electronic device of claim 4, wherein the second controller is configured to, based on acquisition of the signal at a given channel associated with the second controller, scan for the signal at each channel having the direction not parallel to the direction of the given channel, at the acquisition intervals.

6. The electronic device of claim 1, wherein the first controller is configured to acquire the signal based upon the given channel receiving an edge of the signal before other channels of the first controller.

7. The electronic device of claim 1, wherein the first controller is configured to acquire the signal based upon a plurality of channels of the first controller receiving an edge of the signal during a same period of time and the given channel being located physically between channels of the plurality of channels.

8. An electronic device comprising:

a stylus configured to transmit a signal;

a digitizer having channels, each channel being associated with one of a first direction and a second direction;

a first controller associated with some channels of a digitizer in the first direction and some channels of the digitizer in the second direction;

a second controller associated with channels of the digitizer not associated with the first controller; and

wherein the first and second controller are configured to;

synchronize with each other in the first direction based upon a property of the signal as received at a channel associated with the first direction,

scan for the signal at each channel associated with the first direction,

synchronize with each other in the second direction, and

scan for the signal at each channel associated with the second direction;

wherein one of the first controller and the second controller is configured to determine a phase mismatch between an expected signal and the received signal and an associated correction, and to transmit the correction to the other of the first controller and second controller;

wherein one of the first controller and the second controller are configured to filter noise from the signal acquired at each channel, based upon the phase mismatch being greater than a threshold phase mismatch;

wherein the first controller and second controller are configured to correct the signal acquired at each channel, using the correction.

9. The electronic device of claim 8, wherein the first controller and second controller are configured to correct the signal acquired at each channel, using the correction.

10. A method of operating an electronic device comprising:

scanning for a signal from a stylus to each channel of a digitizer associated with a first controller, each channel having a corresponding direction;

calculating a property of the signal based on the signal as acquired at a given channel associated with the first controller, using the first controller;

sending the calculated property and the direction of the given channel to a second controller having channels of the digitizer associated therewith, using the first controller;

scanning for the signal at each channel having the direction of the given channel, at acquisition intervals based upon the calculated property, using the first controller and the second controller;

determining a phase mismatch between an expected signal and the signal acquired at the given channel and an associated phase correction, and sending the phase correction to the second controller, using the first controller;

correcting the signal acquired at each channel having the direction of the given channel, with the phase correction, using the first controller and the second controller; and

filtering noise from the signal acquired at each channel, based upon the phase mismatch being greater than a threshold phase mismatch, using the first controller.

11. The method of claim 10, wherein the property of the signal comprises a period of the signal.

12. The method of claim 10, further comprising scanning for the signal at each channel associated with the first controller and having a direction not parallel to the direction of the given channel, at the acquisition intervals, using the first controller.

13. The method of claim 12, further comprising scanning for the signal at each channel associated with the second controller, based upon a failure of the first controller to acquire the signal at channels having the direction not parallel to the direction of the given channel, using the second controller.

14. The method of claim 13, further comprising scanning for the signal at each channel associated with the second controller having the direction not parallel to the direction of the given channel, at the acquisition intervals, based acquisition of the signal at a given channel associated with the first controller, using the second controller.