Headsets and Headset Power Management

• US 20070076897A1
• Filed: 09/28/2006
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Philipp, Harald
• Granted Patent: US 7,945,297 B2
• Time in Patent Office: Days
• US Class Current: 381/74
• CPC Class Codes: H04R 1/10 Earpieces; Attachments therefor ; Earphones; Monophonic headphones H04R1/28 takes precedence; stereophonic headphones H04R5/033
• CPC Class Codes: H04R 1/1008 Earpieces of the supra-aural or circum-aural type
• CPC Class Codes: H04R 1/1041 Mechanical or electronic switches, or control elements switches in general H01H
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 2430/01 Aspects of volume control, not necessarily automatic, in sound systems
• CPC Class Codes: H04R 2460/03 Aspects of the reduction of energy consumption in hearing devices
• CPC Class Codes: H04R 5/033 Headphones for stereophonic communication details thereof, e.g. relating to batteries, cables or control elements H04R1/10

Abstract

The invention relates to an energy saving headset that comprises a power management unit operable to reduce the power consumption of the headset when a user is not present. The power management unit uses capacitive sensing to detect the presence of the user. Capacitive sensing is advantageous since it provides a flexible and reliable sensor that can accurately detect the presence or absence of a user either by detecting user proximity or user contact. Moreover, in various embodiments, the sensitivity of a capacitive sensor may be adjusted to account for user movement or changes in environmental conditions, such as, for example, the presence of water, or sweat, on the headset to further improve sensing reliability. The invention further relates to headsets using user presence signals based on capacitive sensing to control other functions of the headset or to control external devices to which the headset is connected, either wirelessly or by wires.

Claims

1. A headset comprising:

at least one circuit element;

a capacitive sensor operable to provide a capacitance measurement signal; and

a sensing circuit operable to generate a user presence signal responsive to the capacitance measurement signal indicating whether the headset is being worn and operable to control the at least one circuit element dependent on said user presence signal, or to output an external output signal that is dependent on said user presence signal for receipt by another device to which the headset is connected.

2. The headset of claim 1, wherein the sensing circuit includes a sample capacitor and is further operable to transfer charge from the capacitive sensor to the sample capacitor to generate an electric potential at the sample capacitor for measuring.

3. The headset of claim 2, comprising at least one switch operable to transfer a burst of charge packets sequentially from the capacitive sensor to the sample capacitor prior to any measurement of the electric potential being made.

4. The headset of claim 1, wherein the sensing circuit comprises a consensus filter for generating the user presence signal.

5. The headset of claim 1, wherein the sensing circuit is further operable automatically to perform a self-calibration operation.

6. The headset of claim 1, wherein the capacitive sensor comprises an electrode that is electrically isolated from the user when the headset is being worn.

7. The headset of claim 1, wherein at least one of the circuit elements comprises a wireless communications transceiver.

8. The headset of claim 1, further comprising a power management unit, of which the sensing circuit is a part, and wherein the power management unit is operable to reduce power consumption of the at least one circuit element dependent on said user presence signal, thereby to reduce power consumption of the headset.

9. A method of operating a headset, the method comprising:

measuring the capacitance of a capacitive sensor;

determining from the measured capacitance whether a user is present or not; and

controlling a function of the headset, or outputting an external output signal that can be received by another device to which the headset is connected, in response to determining whether the user is present or not.

10. The method of claim 9, wherein measuring the capacitance of the capacitive sensor includes:

transferring charge from the capacitive sensor to a sample capacitor;

measuring the electric potential at the sample capacitor; and

determining the capacitance of the capacitive sensor from the measured electric potential of the sample capacitor.

11. The method of claim 10, wherein transferring charge from the capacitive sensor to a sample capacitor comprises transferring a burst of charge packets in sequence from the capacitive sensor to a sample capacitor.

12. The method of claim 9, wherein determining whether a user is present or not comprises comparing the measured capacitance of the capacitive sensor to one or more predetermined threshold values in order to determine whether the capacitance of the capacitive sensor has been changed by the proximity of the user.

13. The method of claim 12, comprising adjusting one or more of the threshold values in response to changes in operating conditions.

14. The method of claim 9, wherein said device to which the headset is connected is connected thereto wirelessly.

15. The method of claim 9, wherein said device to which the headset is connected is wired thereto.