Common-mode hover detection

• US 9,354,734 B2
• Filed: 03/04/2014
• Issued: 05/31/2016
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Hermes, Bernard J.
• Primary Examiner(s): Sharifi-Tafreshi, Koosha
• Application Number:
  US14/196,958
• Publication Number:
  US 20150253881A1
• Time in Patent Office: 819 Days
• Field of Search: 345/173, 345/174, 178/18.01, 178/18.06
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

In one embodiment, a method includes substantially simultaneously applying a pre-determined voltage to a conductive layer and to one or more electrodes of a touch sensor. The conductive layer is spatially separated from the electrodes by at least a thickness of a substrate. The method also includes determining a difference between a measurement current of one or more of the electrodes and a reference value; and determining whether a proximity or touch input to the touch sensor has occurred based at least in part on the difference.

Claims

1. A method comprising:

substantially simultaneously applying a pre-determined voltage to a conductive layer and to one or more electrodes of a touch sensor, the conductive layer disposed around at least two sides of a printed-circuit board (PCB), the one or more electrodes situated in a first plane, the conductive layer and the PCB situated in a second plane different than the first plane;

determining a difference between a measurement current of one or more of the electrodes and a reference value; and

determining whether a proximity or touch input to the touch sensor has occurred based at least in part on the difference.

2. The method of claim 1, wherein the determination of the difference comprises integrating the measurement current of one or more of the electrodes.

3. The method of claim 1, wherein the pre-determined voltage comprises a voltage having a square-wave waveform.

4. The method of claim 1, further comprising amplifying the measurement current.

5. The method of claim 1, wherein the application of the pre-determined voltage comprises applying the pre-determined voltage to an input of an integrator circuit.

6. The method of claim 1, wherein the conductive layer is annular shaped and surrounds the PCB.

7. The method of claim 6, wherein a device housing the PCB is held by a user.

8. A computer-readable non-transitory storage medium embodying instructions configured, when executed, to:

substantially simultaneously apply a pre-determined voltage to a conductive layer and to one or more electrodes of a touch sensor, the conductive layer disposed around at least two sides of a printed-circuit board (PCB), the one or more electrodes situated in a first plane, the conductive layer and the PCB situated in a second plane different than the first plane;

determine a difference between a measurement current of one or more of the electrodes and a reference value; and

determine whether a proximity or touch input to the touch sensor has occurred based at least in part on the difference.

9. The medium of claim 8, wherein the instructions are further configured to integrate the measurement current of one or more of the electrodes.

10. The medium of claim 8, wherein the pre-determined voltage comprises a voltage having a square-wave waveform.

11. The medium of claim 8, wherein the instructions are further configured to amplify the measurement current.

12. The medium of claim 8, wherein the instructions are further configured to apply the pre-determined voltage to an input of an integrator circuit.

13. The medium of claim 8, wherein the conductive layer is annular shaped and surrounds the PCB.

14. The medium of claim 13, wherein a device housing the PCB is held by a user.

15. A device comprising:

a measurement circuit;

a touch sensor; and

a computer-readable non-transitory storage medium coupled to the measurement circuit and embodying instructions configured, when executed, to;

substantially simultaneously apply a pre-determined voltage to a conductive layer and to one or more electrodes of the touch sensor, the conductive layer disposed around at least two sides of a printed-circuit board (PCB), the one or more electrodes situated in a first plane, the conductive layer and the PCB situated in a second plane different than the first plane;

determine a difference between a measurement current of one or more of the electrodes and a reference value; and

determine whether a proximity or touch input to the touch sensor has occurred based at least in part on the difference.

16. The device of claim 15, wherein the pre-determined voltage comprises a voltage having a square-wave waveform.

17. The device of claim 15, wherein the instructions are further configured to apply the pre-determined voltage to an input of an integrator circuit.