Multi-touch capacitive sensing surface

Patent metadata

Field	Value
Publication number	US-10120506-B2
Application number	US-201314078383-A
Country	US
Kind code	B2
Filing date	Nov 12, 2013
Priority date	Nov 12, 2013
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

Disclosed are techniques and systems for distinguishing between inadvertent contact and an intentional key press on a touch-sensitive input device, such as a keyboard or other like peripheral. In some embodiments, a system may include a first electrode disposed in a first plane, and a second electrode disposed in a second plane substantially parallel to the first plane. The system may also include one of a flexible dielectric material and an air gap spacing the first electrode from the second electrode; and a third electrode disposed in a third plane substantially parallel to the first plane. The third electrode may extend substantially parallel to the first electrode, and may be spaced from the first electrode by the one of the flexible dielectric material and the air gap.

First claim

What is claimed is:

1. A system, comprising:
a processor;
a computer readable media operably connected to the processor; and
a touch-sensitive input device operably connected to one or more of the processor and the computer readable media, the touch-sensitive input device including:
a surface;
a plurality of keys configured to enable user input via the touch-sensitive input device;
a first plurality of substantially parallel electrodes disposed in a first plane;
a second plurality of substantially parallel electrodes disposed in a second plane substantially parallel to the first plane in which an electrode of the second plurality of electrodes extends substantially perpendicular to an electrode of the first plurality of electrodes;
a third plurality of substantially parallel electrodes disposed in a third plane substantially parallel to the first plane and the second plane, in which an electrode of the third plurality of electrodes extends substantially parallel to the electrode of the first plurality of electrodes; and
at least one of a flexible dielectric material or an air gap spacing the first plurality of electrodes from the second plurality of electrodes, wherein:
the first plurality of electrodes and the second plurality of electrodes are configured to determine a first capacitance associated with a conductor contacting the surface, wherein the first capacitance indicates a pressure of the conductor contacting the surface; and
the second plurality of electrodes and the third plurality of electrodes are configured to determine a second capacitance substantially simultaneously with the first capacitance, wherein the second capacitance indicates a location on the surface of the input device at which the conductor contacts the surface relative to the keys of the input device;
one of the first capacitance or the second capacitance being determined based at least in part on a self-capacitance measurement, and the other of the first capacitance and the second capacitance being determined based at least in part on a mutual-capacitance measurement; and
the processor configured to classify the contact between the conductor and the surface as being one of an inadvertent contact or an intentional key press based, at least in part, on the first capacitance, the second capacitance, a pressure threshold value associated with an inadvertent contact measured using the first capacitance and a location threshold value associated with known input mechanisms measured using the second capacitance.

2. The system of claim 1 , wherein the first capacitance is determined based, at least in part, on the self-capacitance measurement and the second capacitance is determined based at least in part on the mutual-capacitance measurement.

3. The system of claim 1 , wherein the second and third pluralities of electrodes are configured to determine a decrease in mutual-capacitance associated with the conductor approaching the surface, and wherein the first and second pluralities of electrodes are configured to determine an increase in self-capacitance associated with the conductor applying pressure to the surface.

4. The system of claim 1 , wherein in the touch-sensitive input device is implemented as a keyboard that is external to an associated computing device.

5. The system of claim 1 , wherein the known input mechanisms are keys of a keyboard.

6. A touch-sensitive input device, comprising:
a first electrode disposed in a first plane;
a second electrode disposed in a second plane substantially parallel to the first plane, the second electrode extending substantially perpendicular to the first electrode;
at least one of a flexible dielectric material or an air gap spacing the first electrode from the second electrode, the first electrode and the second electrode configured to determine a first capacitance associated with a conductor contacting a surface of the touch-sensitive input device; and
a third electrode disposed in a third plane substantially parallel to the first plane, the third electrode extending substantially parallel to the first electrode and being spaced from the first electrode by the at least one of the flexible dielectric material or the air gap, the second electrode and the third electrode configured to determine a second capacitance substantially simultaneously with the first capacitance, wherein:
one of the first capacitance or the second capacitance is determinable based, at least in part, on a self-capacitance measurement;
the other of the first capacitance and the second capacitance is determinable based, at least in part, on a mutual-capacitance measurement; and
the contact between the conductor and the surface of the touch-sensitive input device is classifiable as one of an inadvertent contact or an intentional contact based, at least in part, on the first capacitance, the second capacitance, a pressure threshold value associated with an inadvertent contact measured using one of the first capacitance and the second capacitance and a location threshold value associated with known input mechanisms measured using the other of the first capacitance and the second capacitance.

7. The system of claim 6 , further comprising a flexible printed circuit board spaced from the first electrode by the at least one of the dielectric material or the air gap, the second electrode being fixed to the printed circuit board.

8. The system of claim 6 , wherein the second electrode is disposed between the first electrode and the third electrode.

9. The system of claim 6 , wherein the first electrode is one of a first plurality of substantially parallel electrodes disposed in the first plane, the second electrode is one of a second plurality of substantially parallel electrodes disposed in the second plane, and the third electrode is one of a third plurality of substantially parallel electrodes disposed in the third plane.

10. The system of claim 6 , wherein the at least one of the dielectric material or the air gap is disposed between the first plane and the third plane.

11. The system of claim 6 , wherein the first electrode and the third electrode both comprise one of a capacitive receiver or a capacitive transmitter, and wherein the second electrode comprises the other of the capacitive receiver or the capacitive transmitter.

12. The system of claim 6 , wherein the first electrode and the second electrode are configured to determine a first characteristic associated with the conductor contacting the surface of the touch-sensitive input device based at least in part on the self-capacitance measurement, and the second and the third electrodes are configured to determine a second characteristic associated with the conductor contacting the surface of the touch-sensitive input device based at least in part on the mutual-capacitance measurement.

13. The system of claim 12 , wherein the first characteristic comprises the pressure applied to the surface of the touch-sensitive input device by the conductor and the second characteristic comprises the location on the surface of the touch-sensitive input device at which the conductor contacts the surface of the touch-sensitive input device.

14. The system of claim 12 , wherein one of the first, second, and third electrodes are configured to determine the first and second characteristics substantially simultaneously.

15. The system of claim 6 , wherein the touch-sensitive input device is a keyboard.

16. A method, comprising:
determining a first capacitance associated with a conductor contacting a surface of a touch-sensitive input device, the touch-sensitive input

Assignees

• Microsoft Technology Licensing Llc
• Microsoft Technology Licensing Llc

Inventors

• Chen Li-Wen (Magnetro)
• Hsu Feng-Hsiung

Classifications

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0414

  using force sensing means to determine a position · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F2203/04111

  Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate · CPC title

• G06F2203/04102

  Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper · CPC title