SENSING

• US 20150097581A1
• Filed: 09/26/2014
• Published: 04/09/2015
• Est. Priority Date: 10/03/2013
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Cotton, Darryl, Kivioja, Jani, Astley, Michael
• Granted Patent: US 9,886,143 B2
• Time in Patent Office: Days
• US Class Current: 324/658
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• 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 3/0362 with detection of 1D translations or rotations of an operating part of the device, e.g. scroll wheels, sliders, knobs, rollers or belts
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches

Abstract

An apparatus comprising: a capacitance touch sensor arrangement configured to have a variable capacitance that varies when a conductive object approaches; and at least one variable impedance sensor configured to have a variable impedance that varies with a sensed parameter;

• an output node; and at least one switch configured to provide, in a first configuration,] an output impedance at the output node that depends upon the variable capacitance and configured to provide, in a second configuration,
• an output impedance at the output node that depends upon the variable impedance.

Claims

1. An apparatus comprising:

a capacitance touch sensor arrangement having a variable capacitance; and

at least one sensor, the sensor having a variable impedance;

an output node;

an output impedance at the output node; and

at least one switch configured to connect, in a first configuration,

the output node to the variable capacitance and configured to connect, in a second configuration,

the output node to the variable impedance.

2. An apparatus as claimed in claim 1, wherein the at least one switch is configured, in the first configuration, to connect a first electrode to the output node via a low impedance path.

3. An apparatus as claimed in claim 1, wherein the at least one switch is configured, in the second configuration, to connect the variable impedance between a reference node and the output node.

4. An apparatus as claimed in claim 1, wherein the at least one switch is configured, in the first configuration, to reduce an impedance between a first electrode and a second electrode.

5. An apparatus as claimed in claim 1, wherein the at least one switch is configured, in the first configuration, to interconnect a first electrode and a second electrode.

6. An apparatus as claimed in claim 5, wherein the at least one switch is configured, in the first configuration, to interconnect the first electrode and the second electrode in electrical series via a low impedance current path through the at least one switch to provide an alternative to a current path through the variable impedance.

7. An apparatus as claimed in claim 1, wherein in the first configuration, the lowest impedance path between the first electrode and the second electrode is via the at least one switch and not via the variable impedance.

8. An apparatus as claimed in claim 1, wherein in the second configuration, the lowest impedance current path between a first electrode and a second electrode is via the variable impedance.

9. An apparatus as claimed in claim 1, wherein the apparatus comprises a first electrode, the first electrode being is a first electrode of the variable capacitance and also a first electrode of the variable impedance

10. An apparatus as claimed in claim 9, wherein the apparatus comprises a second electrode connected in electrical series to the output node, is a second electrode of the variable capacitance and also a second electrode of the variable impedance.

11. An apparatus as claimed in claim 10, wherein the at least one switch is configured to provide, in the first configuration, a low impedance current path in parallel to the variable impedance between the first and second electrodes.

12. An apparatus as claimed in claim 11, wherein the switch is configured, in the second configuration, to connect the first electrode to a reference node via a low impedance current path.

13. An apparatus comprising:

a first electrode,

a second electrode configured to provide an output signal,

and

a switch configured to switch between a first configuration and a second configuration, an impedance between the first electrode and the second electrode being lower in the first configuration than in the second configuration,

wherein, in the first configuration, the first and second electrodes form a capacitance touch sensor arrangement configured to have a variable capacitance;

wherein, in the second configuration, the first and second electrodes form a sensor having a variable impedance.

14. An apparatus as claimed in claim 13, wherein the switch is configured, in the first configuration, to provide a low impedance current path between the first electrode and the second electrode.

15. An apparatus as claimed in claim 13, wherein the switch is configured, in the first configuration, to interconnect the first electrode and the second electrode.

16. An apparatus as claimed in claim 13, wherein the first electrode and the second electrode form a variable impedance configured to vary with a particular parameter.

17. An apparatus as claimed in claim 13, wherein the first electrode and the second electrode form a capacitor comprising a dielectric having a relative permittivity configured to vary with a particular parameter.

18. An apparatus as claimed in claim 13, comprising a control circuitry configured to control the switch.

19. An apparatus as claimed in claim 13, comprising a detection circuitry configured to detect the output signal.

20. An apparatus as claimed in claim 18, wherein the control circuitry is configured to cause the output signal to depend, in the first configuration, upon the variable capacitance and, in the second configuration, upon the variable impedance.