STYLUS TO HOST SYNCHRONIZATION USING A MAGNETIC FIELD

• US 20130207939A1
• Filed: 03/27/2012
• Published: 08/15/2013
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Kremin, Viktor, Ryshtun, Andriy
• Granted Patent: US 10,228,780 B2
• Time in Patent Office: Days
• US Class Current: 345/179
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• 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 3/03547 Touch pads, in which fingers can move on a surface
• 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 3/04166 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 3/0441 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

A system and method for synchronizing a stylus to a capacitive sense array. The system including a capacitive sense array which includes a plurality of electrodes. A magnetic field is generated using the plurality of electrodes. The magnetic field is used to synchronize the operation of the stylus and the capacitive sense array.

Claims

1. An apparatus comprising:

a capacitive sense array comprising a plurality of electrodes, wherein the plurality of electrodes is configured to generate a magnetic field to synchronize a stylus.

2. The apparatus of claim 1, wherein the magnetic field comprises an H-field.

3. The apparatus of claim 2, wherein the magnetic field is generated by propagating an electrical current through the plurality of electrodes.

4. The apparatus of claim 1, wherein the plurality of electrodes is configured to generate the magnetic field during a first time interval and wherein a second plurality of electrodes is configured to receive a transmit signal from the stylus during the first time interval.

5. The apparatus of claim 1, wherein the plurality of electrodes is configured to generate the magnetic field during a first time interval and wherein a second plurality of electrodes is configured to receive a transmit signal from the stylus after the first time interval.

6. The apparatus of claim 1, wherein the plurality of electrodes is positioned along one or more edges of the capacitive sense array.

7. The apparatus of claim 1, wherein the plurality of electrodes is connected in series to a voltage source.

8. A method comprising:

providing a plurality of electrodes in a capacitive sense array; and

synchronizing a timing of a stylus using a magnetic field generated by the plurality of electrodes.

9. The method of claim 8, wherein the magnetic field comprises an H-field.

10. The method of claim 9, wherein the magnetic field is generated by propagating an electrical current through the plurality of electrodes.

11. The method of claim 8, wherein the plurality of electrodes is configured to generate the magnetic field during a first time interval and wherein synchronizing the time of the stylus comprises receiving a transmit signal from the stylus during the first time interval using a second plurality of electrodes.

12. The method of claim 8, wherein the plurality of electrodes is configured to generate the magnetic field during a first time interval and wherein synchronizing the timing of the stylus comprises receiving a transmit signal from the stylus after the first time interval using a second plurality of electrodes.

13. The method of claim 8, wherein the plurality of electrodes is positioned along one or more edges of the capacitive sense array.

14. The method of claim 8, wherein the plurality of electrodes is connected in series to a voltage source.

15. A stylus comprising:

a sensor configured to detect a magnetic field generated by a plurality of electrodes; and

a processing device configured to generate a transmit signal based on the magnetic field.

16. The stylus of claim 15, further comprising:

a transmitter configured to transmit the transmit signal to a capacitive sense array.

17. The stylus of claim 15, wherein the processing device is further configured to generate the transmit signal while the sensor device detects the magnetic field.

18. The stylus of claim 15, wherein the processing device is further configured to generate the transmit signal after the sensor device detects the magnetic field.

19. The stylus of claim 15, wherein the magnetic field comprises an H-field.

20. The stylus of claim 16, wherein the transmit signal is transmitted to the capacitive sense array by capacitively coupling the stylus to one or more electrodes in the capacitive sense array.