Capacitive in ear detect on earphones

1 . An earphone comprising:

a device housing that defines an internal cavity within the device housing;

an acoustic port formed through the device housing and having an opening at an exterior surface of the device housing;

an audio driver disposed within the device housing and aligned to emit sound through the acoustic port;

a plurality of capacitive pixels disposed within the internal cavity, wherein each capacitive pixel comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area, a conductive shield layer, and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the internal cavity and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine if the earphone is within an ear of a user, wherein the sensor control circuitry is configured to apply a pulsed voltage to the guard ring and the conductive shield layer at a same frequency and time as the plurality of capacitive pixels are driven.

2 . The earphone set forth in claim 1 wherein:

the device housing includes a housing wall that defines both an exterior surface of the earphone and an interior surface of the device housing;

the earphone further comprises a plurality of recessed regions formed in the housing wall; and

each capacitive pixel in the plurality of capacitive pixels is disposed within a unique one of the plurality of recessed regions.

3 . The earphone set forth in claim 2 wherein each capacitive pixel has a thickness of 500 microns or less.

4 . The earphone set forth in claim 1 wherein at least two of the capacitive pixels in the plurality of capacitive pixels are disposed radially around the acoustic port and spaced apart from each other by at least 120 degrees.

5 . The earphone set forth in claim 1 wherein a diameter of a sensing area of each capacitive pixel in the plurality of capacitive pixels is 4 mm or less.

6 . The earphone set forth in claim 1 wherein the sensor control circuitry determines if the earphone is within an ear of a user based on a predetermined in-ear detect algorithm that includes determining whether or not multiple measured capacitance values of the two or more pixels are greater than or less than a predetermined threshold.

7 . The earphone set forth in claim 1 wherein the sensor control circuitry determines if the earphone is within an ear of a user based an artificial intelligence engine.

8 . An earphone comprising:

a device housing that defines an internal cavity within the device housing;

an acoustic port formed through the device housing and having an opening at an exterior surface of the device housing;

an audio driver disposed within the device housing and aligned to emit sound through the acoustic port;

a plurality of capacitive pixels disposed within the internal cavity, wherein each capacitive pixel comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area, a conductive shield layer, and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the internal cavity and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine if the earphone is within an ear of a user;

wherein the sensor control circuitry is configured to drive the plurality of pixels in accordance with a multi-step process in which the capacitance of each capacitive pixel is measured at one point in time with the guard ring and conductive shield layer grounded and then measured at a second point in time with the guard ring and conductive shield layer pulsed with a signal that mimics a sensing pulse applied to a sensing area of each capacitive pixel.

9 . An earphone comprising:

a device housing that includes a housing wall that defines both an exterior surface of the earphone and an interior surface of the device housing;

an acoustic port formed through the device housing and having an opening at an exterior surface of the device housing;

an audio driver disposed within the device housing and aligned to emit sound through the acoustic port;

a plurality of recessed regions formed in the housing wall;

a plurality of capacitive pixels disposed within the device housing, wherein each capacitive pixel in the plurality of capacitive pixels is disposed within a unique one of the plurality of recessed regions and comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area, a conductive shield layer, and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the device housing and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine, based on an algorithm, if the earphone is within an ear of a user, and wherein the sensor control circuitry is configured to apply a pulsed voltage to the guard ring and the conductive shield layer at a same frequency and time as the plurality of capacitive pixels are driven.

10 . An earphone comprising:

a device housing that includes a housing wall that defines both an exterior surface of the earphone and an interior surface of the device housing;

an acoustic port formed through the device housing and having an opening at an exterior surface of the device housing;

an audio driver disposed within the device housing and aligned to emit sound through the acoustic port;

a plurality of recessed regions formed in the housing wall;

a plurality of capacitive pixels disposed within the device housing, wherein each capacitive pixel in the plurality of capacitive pixels is disposed within a unique one of the plurality of recessed regions and wherein each capacitive pixel comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area; a conductive shield layer; and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the device housing and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine, based on an algorithm, if the earphone is within an ear of a user;

wherein the sensor control circuitry is configured to drive the plurality of pixels in accordance with a multi-step process in which the capacitance of each capacitive pixel is measured at one point in time with the guard ring and conductive shield layer grounded and then measured at a second point in time with the guard ring and conductive shield layer pulsed with a signal that mimics a sensing pulse applied to a sensing area.

11 . A portable acoustic device comprising:

a device housing comprising a speaker housing portion and a stem portion extending away from the speaker housing portion, wherein the speaker housing portion and stem portion combine to define an internal cavity within the device housing;

an acoustic port formed through a wall of the speaker housing portion and having an opening at an exterior surface of the device housing;

an audio driver disposed within the speaker housing portion and aligned to emit sound through the acoustic port;

a plurality of capacitive pixels disposed within the internal cavity, wherein each capacitive pixel comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area, a conductive shield layer, and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the internal cavity and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine, based on an algorithm, if the portable acoustic device is within an ear of a user, wherein the sensor control circuitry is configured to apply a pulsed voltage to the guard ring and the conductive shield layer at a same frequency and time as the plurality of capacitive pixels are driven.

12 . The portable acoustic device set forth in claim 11 wherein:

the device housing includes a housing wall that defines both an exterior surface of the earphone and an interior surface of the device housing;

the earphone further comprises a plurality of recessed regions formed in the housing wall; and

each capacitive pixel in the plurality of capacitive pixels is disposed within a unique one of the plurality of recessed regions.

13 . The portable acoustic device set forth in claim 12 wherein each capacitive pixel has a thickness of 100 microns or less and a diameter of a sensing area of each capacitive pixel in the plurality of capacitive pixels is 4 mm or less.

14 . A portable acoustic device comprising:

a device housing comprising a speaker housing portion and a stem portion extending away from the speaker housing portion, wherein the speaker housing portion and stem portion combine to define an internal cavity within the device housing;

an acoustic port formed through a wall of the speaker housing portion and having an opening at an exterior surface of the device housing;

an audio driver disposed within the speaker housing portion and aligned to emit sound through the acoustic port;

a plurality of capacitive pixels disposed within the internal cavity, wherein each capacitive pixel comprises a stack of layers including: a first conductive layer comprising an active area and a guard ring surrounding and spaced apart from the active area, a conductive shield layer, and a dielectric layer disposed between the first conductive layer and the conductive shield layer; and

sensor control circuitry disposed within the internal cavity and operatively coupled to drive the plurality of capacitive pixels at a predetermined frequency to readout a capacitance at each of the plurality of capacitive pixels and determine, based on an algorithm, if the portable acoustic device is within an ear of a user; and

wherein the sensor control circuitry is configured to drive the plurality of pixels in accordance with a multi-step process in which the capacitance of each capacitive pixel is measured at one point in time with the guard ring and conductive shield layer grounded and then measured at a second point in time with the guard ring and conductive shield layer pulsed with a signal that mimics a sensing pulse applied to a sensing area.