System and method to share electrodes between capacitive touch controller and gesture detection device

• US 9,342,195 B2
• Filed: 03/11/2013
• Issued: 05/17/2016
• Est. Priority Date: 03/12/2012
• Status: Active Grant

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Microchip Technology Incorporated
• Inventors: Zhang, Ce
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Suteerawongsa, Jarurat
• Application Number:
  US13/792,823
• Publication Number:
  US 20130249855A1
• Time in Patent Office: 1,163 Days
• Field of Search: 345173-174
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A system may have a touch controller, a gesture detection device, and a capacitive sensor having at least one first and at least one second electrode, wherein the at least one first electrode is coupled with a controllable generator for supplying an AC signal to the first electrode. Furthermore, a configurable coupling is provided between the at least one second electrode, an input of the touch controller and an input of the gesture detection device, wherein the coupling can be configured to allow the system to perform a touch detection from signals received from the second electrode by the touch controller in a first configuration mode and to perform a gesture detection from signals received from the second electrode by the gesture detection device in a second configuration mode.

Claims

1. A system comprising:

a capacitive touch controller,

a gesture detection device,

a capacitive sensor having at least one first and at least one second electrode, wherein the at least one first electrode is coupled with a controllable generator for supplying an AC signal to said first electrode; and

a configurable coupling between the at least one second electrode, an input of the touch controller and an input of the gesture detection device, wherein the coupling can be configured to allow the system to perform a touch detection from signals received from said second electrode by the touch controller in a first configuration mode in which said controllable generator is turned off and to perform a gesture detection from signals received from said second electrode by the gesture detection device in a second configuration mode in which said controllable generator is turned on.

2. The system according to claim 1, wherein the coupling comprises a switching arrangement operable to connect the second electrode to either the touch controller or the gesture detection device.

3. The system according to claim 2, wherein the switching arrangement comprises a multiplexer.

4. The system according to claim 2, wherein the switching arrangement comprises a Single Pole Double Throw switch (SPDT).

5. The system according to claim 4, further comprising a resistor connected between an input of the touch controller and ground.

6. The system according to claim 5, further comprising a current source coupled with the resistor.

7. The system according to claim 1, further comprising a resistor connected between an input of the gesture detection device and a direct current (DC) voltage.

8. The system according to claim 1, further comprising a synchronization connection between the touch controller and the gesture detection device.

9. The system according to claim 8, wherein the synchronization connection comprises a first synchronization line configured to signal a status from the touch controller to the gesture detection device and a second synchronization line configured to signal a status from the gesture detection device to the touch controller.

10. The system according to claim 8, wherein the synchronization connection comprises a bidirectional communication interface between the touch controller and the gesture detection device.

11. The system according to claim 10, wherein the bidirectional communication interface is an I²C interface.

12. The system according to claim 1, wherein the second electrode is coupled with an input of the touch controller and an input of the gesture detection device, and wherein the input of the touch controller is operable to be switched into a high impedance mode when the coupling is configured to operate in the second configuration mode, wherein the controllable generator supplies the AC signal to the first electrode in the second configuration mode.

13. The system according to claim 12, further comprising a synchronization connection between the touch controller and the gesture detection device.

14. The system according to claim 13, wherein the synchronization connection comprises a first synchronization line configured to signal a status from the touch controller to the gesture detection device and a second synchronization line configured to signal a status from the gesture detection device to the touch controller.

15. The system according to claim 13, wherein the synchronization connection comprises a bidirectional communication interface between the touch controller and the gesture detection device.

16. The system according to claim 15, wherein the bidirectional communication interface is an I²C interface.

17. The system according to claim 1, wherein the second electrode is connected to an input of the gesture detection device, and the coupling comprises a single pole single throw switch having a low off-isolation value and a low switch-on capacitance and being operable to connect the second electrode to the touch controller.

18. The system according to claim 1, wherein the second electrode is connected to an input of the touch controller, and the coupling comprises a single pole single throw switch having a low off-isolation value and a low switch-on capacitance and being operable to connect the second electrode to the gesture detection device.

19. A method for performing touch and non-touch gesture detection in a system comprising a touch controller and a non-touch gesture detection device configured to be coupled with one electrode of a capacitive sensor device wherein another electrode of the capacitive sensor device is coupled with a controllable generator for supplying an AC signal to said another electrode, the method comprising:

configuring a coupling between the one electrode of said capacitive sensor and an input of the touch controller or an input of the gesture detection device, wherein the coupling is configured in a first configuration mode to allow the system to perform a touch detection from signals received from said second electrode by the touch controller wherein said controllable generator is turned off and in a second configuration mode to perform a gesture detection from signals received from said second electrode by the gesture detection device, wherein the controllable generator is turned on to supply the AC signal to said another electrode when in said second configuration mode.

20. The method according to claim 19, wherein the coupling comprises a switching arrangement between said second electrode and inputs of said touch controller and said gesture detection device, the method further comprising

during said first configuration mode decoupling the second electrode from the input of the gesture detection device and coupling the second electrode with the touch controller and during the second configuration mode decoupling the second electrode from the input of the touch controller and coupling the second electrode with the gesture detection device.

21. The method according to claim 20, wherein the second electrode is coupled with an input of the touch controller and an input of the gesture detection device, and the method further comprises:

during the second configuration mode switching the input of the touch controller into a high impedance mode.

22. The method according to claim 21, further comprising a synchronization connection between the touch controller and the gesture detection device, the method further comprising the steps:

signaling the end of a respective detection process by said gesture detection device and said touch controller to each other by means of the synchronization connection.

23. The method according to claim 22, wherein the synchronization connection comprises a first synchronization line configured to signal a status from the touch controller to the gesture detection device and a second synchronization line configured to signal a status from the gesture detection device to the touch controller.

24. The method according to claim 22, wherein the synchronization connection comprises a bidirectional communication interface between the touch controller and the gesture detection device.

25. The method according to claim 24, further comprising:

configuring the gesture detection device as a master and the touch controller as a slave device and communication data determined by the touch controller to the gesture detection device.

26. The method according to claim 25, further comprising:

communicating all data determined by the touch controller and the gesture detection device to a superior processor by said gesture detection device.

27. The method according to claim 19, wherein the second electrode is connected to an input of the gesture detection device, the method further comprising:

during the first configuration mode connecting the second electrode to the touch controller using a single pole single throw switch.

28. The method according to claim 19, wherein the second electrode is connected to an input of the touch controller, the method further comprising:

during the second configuration mode connecting the second electrode to the gesture detection device using a single pole single throw switch.

29. A system comprising:

a capacitive touch controller,

a gesture detection device configured to determine a three-dimensional position of an object from signals received from a plurality of receiving electrodes,

a capacitive sensor having at least one first and at least one second electrode, wherein the at least one first electrode is coupled with a controllable generator for supplying an AC signal to said first electrode; and

a configurable coupling between the at least one second electrode, an input of the touch controller and an input of the gesture detection device, wherein the coupling can be configured to allow the system to perform a touch detection from signals received from said second electrode by the touch controller in a first configuration mode in which said controllable generator is turned off and to perform a gesture detection from signals received from said second electrode by the gesture detection device in a second configuration mode in which said controllable generator is turned on, wherein said at least one first electrode is used as a transmitting electrode to generate an electric field and the at least one second electrode is used as one of the plurality of receiving electrodes.