Patent Description:
"Truly wireless", when used in connection with earbuds, is typically used to refer to a pair of earbuds (one for each ear) that connect to an audio source wirelessly, with no wire between the earbuds. A pair of truly wireless earbuds may be used for a number of purposes, such as listening to audio signals transmitted by a device, noise cancelation, voice calls, and translation. Sensors are often included in these wireless earbuds for detecting different conditions, such as whether the wireless earbuds are loose or inserted into ears.

The present disclosure provides for a device according to claim <NUM>.

The one or more processors may be further configured to determine that the combined capacitance meets a predetermined threshold capacitance, wherein detecting whether the conductive support is inserted into the ear is based on whether the combined capacitance meeting the predetermined threshold capacitance. The one or more processors may be further configured to detect, based on the combined capacitance, that the conductive support is within a predetermined distance from a skin surface inside the ear.

The conductive support may have a tubular shape configured to be inserted into an ear canal.

The device may further comprise a speaker. The one or more processors may be further configured to control the speaker to generate an audio output when operating in the first mode.

The one or more processors may be further configured to operate the device in at least one further mode and/or to trigger at least one action based on the measured combined capacitance. For example, the one or more processors may be further configured to operate the device in a second mode based on detecting that the conductive support is not inserted into the ear. The second mode may be a standby mode.

The device may further comprise a communication module; wherein the one or more processors may be further configured to control the communication module to send a message instructing another electronic device to generate audio output when operating in the second mode. The one or more processors may be further configured to, based on the combined capacitance, detect at least one further state of the device in addition to detecting whether the conductive support is inserted into an ear or not. For example, the one or more processors may be further configured to detect, based on the combined capacitance and as at least one further state, whether the device is inserted incorrectly in the ear.

The device may further comprise a non-conductive cap positioned around the conductive support outside the housing, wherein, when the conductive support is inserted into the ear, the non-conductive cap comes in direct contact with a skin surface of the ear. The one or more processors may be further configured to detect, based on the combined capacitance, whether the earbud is inserted incorrectly; and generate, based on detecting that the earbud is inserted incorrectly, an output including an instruction to adjust the non-conductive cap. Generally, the conductive cape may include at least one opening for sound. The one or more processors may be further configured to determine whether the combined capacitance meets a first predetermined threshold capacitance or a second predetermined threshold capacitance being higher than the first predetermined threshold capacitance. Detecting whether the conductive support is inserted into the ear or not may then be based on whether the combined capacitance meeting the first predetermined threshold capacitance and detecting whether the device is in another state may be based on whether the combined capacitance meeting the higher second predetermined threshold capacitance. For example, the combined capacitance measured without a non-conductive cap may have a much larger value greater than the first predetermined threshold capacitance, such as a value meeting a second predetermined (higher) threshold capacitance. Based on detecting that the device is not being worn correctly, the one or more processors may generate an output instructing the user to correctly insert the device.

The device may further comprise a detector for measuring the combined capacitance; and a transient-voltage-suppression diode connected in parallel to the detector.

The device may further include an optical sensor positioned inside the housing; wherein the one or more processors may be further configured to: receive sensor data from the optical sensor; and detect, further based on the sensor data from the optical sensor, that the conductive support is inserted into the ear.

The present disclosure further provides for a system comprising a first earbud and one or more processors. The first earbud may include a first housing and a first conductive support attached to the first housing. The one or more processors may be configured to measure a first combined capacitance of a first plurality of electrodes at the first conductive support; detect, based on the first combined capacitance, that the first conductive support is inserted into an ear; and operate the first earbud in a first mode based on detecting that the first conductive support is inserted into the ear. The first mode may include controlling the first earbud to generate an audio output.

The system may further include a second earbud. The second earbud may include a second housing and a second conductive support attached to the second housing. The one or more processors may be further configured to measure a second combined capacitance of a second plurality of electrodes at the second conductive support; detect, based on the second combined capacitance, that the second conductive support is not inserted into an ear; operate the second earbud in a second mode based on detecting that the second conductive support is not inserted into the ear. The second mode may be a standby mode.

The present disclosure still further provides for measuring, using the claimed device, by one or more processors, a combined capacitance of a plurality of electrodes at a conductive support attached to a housing of a device; detecting, by the one or more processors based on the combined capacitance, whether the conductive support is inserted into an ear; determining, by the one or more processors whether the conductive support is inserted into the ear; and operating, by the one or more processors, the device in a first mode based on determining that the device is inserted into the ear.

Detecting, by the one or more processors based on the combined capacitance, whether the conductive support is inserted into an ear may comprise detecting, by the one or more processors based on the combined capacitance, whether the conductive support is within a predetermined distance from a skin surface inside the ear, and determining, by the one or more processors based on the combined capacitance, whether the conductive support is inserted into the ear may comprise determining, by the one or more processors based on the combined capacitance, whether the conductive support is within the predetermined distance from the skin surface inside the ear.

The method may further comprise receiving, by the one or more processors, sensor data from an optical sensor; and detecting, by the one or more processors further based on the sensor data from the optical sensor, whether the earbud is being worn.

The technology generally relates to on-body detection for a device. For example, earbuds and the systems in which they operate may be configured to provide enriched user experience based on whether the earbuds are being worn by the user. For instance, when the earbuds are being worn (such as being worn in the ear versus held in a person's hand or placed in a container), audio may be routed to speakers in the earbuds instead of a speaker in another device, such as a paired phone. As another example, if a call comes in when the earbuds are not being worn, audio may be routed to a speaker in another device, such as the paired phone. Further, to conserve battery power and battery life, the earbuds may enter a standby mode when not being worn. Accurately detecting whether earbuds are properly worn may prevent issues that arise from inaccurate detection. For instance, inaccurate detection of the earbuds being worn may cause audio to be routed incorrectly, which may result in inconvenience to the user and others. For example, routing music to a speaker in a paired phone in a quiet library or a crowded street, instead of the earbuds in the user's ears, may cause inconvenience to the user and others. Inaccurate detection of the earbuds being worn may also cause the earbuds to remain in active modes at unnecessary times, which may result in a wasteful use of battery power and a reduced battery life. In this regard, a pair of earbuds are provided with capabilities to detect whether the earbuds are being worn.

For instance, each of the earbuds may include a housing, and a conductive support attached to the housing. By way of example, the conductive support may have a snout-like shape configured to be inserted into the ear. In some instances, the conductive support may have a tubular shape and act as a sound port for the earbud, in addition to providing mechanical support. Moreover, a non-conductive cap may be provided around the conductive support. For example, the non-conductive cap may be configured to come in direct contact with a skin surface of the ear to provide a secure and comfortable fit. In some instances, a diode, such as a transient-voltage-suppression diode, may be provided to protect the conductive support from static charges.

Each of the earbuds may further include one or more processors configured to measure one or more capacitances, such as a combined capacitance of a plurality of electrodes at the conductive support. For example, when not being worn, current passing through the conductive support may be affected to a lesser extent, or not affected at all, by the body of the user. As such, the processors may measure one combined capacitance at the conductive support when the earbuds are not worn. In contrast, when being worn, current passing through the conductive support may be affected to a greater extent by the body of the user. As such, the processors may measure another combined capacitance at the conductive support when the earbuds are worn.

Thus, based on the measured combined capacitance at the conductive support, the processors may detect whether the earbud is being worn. For example, if the measured combined capacitance meets a predetermined threshold capacitance, the processors may determine that the earbud is being worn. Otherwise, the processors may determine that the earbud is not being worn. In some instances, the processors may further make the determination based on sensor data from at least one another sensor, such as an optical sensor, or an IMU. Accordingly, the one or more processors may, for example, take into account both the determination based on the sensor data and the combined capacitance. Thereby, reliability of the determination may be increased.

The processors may then operate the earbuds based on the detection. For instance, the processors may operate the earbud in a first mode based on detecting that the earbud is being worn. By way of example, the processors may route audio to be outputted by a speaker of the earbud, or control the earbud to enter an active mode from a standby mode. The processors may operate the earbud in a second mode based on detecting that the earbud is not being worn. For example, the processors may route audio to be outputted by a speaker in another device, or control the earbud to enter the standby mode.

In another aspect, the processors may be configured to further detect whether the earbud is inserted correctly into the ear. For instance, when the non-conductive cap is removed from the earbud when being worn, the conductive support may come in direct contact with the skin. As such, the processors may measure a combined capacitance at the conductive support that is different from the case when the earbud is worn with the non-conductive cap, and also different from the case when the earbud is not being worn at all. For example, the combined capacitance measured without the non-conductive cap may have a much larger value greater than the predetermined threshold capacitance, such as a value meeting a predetermined high threshold capacitance. Based on detecting that the earbud is not being worn correctly, the processors may generate an output instructing the user to correctly insert the earbud.

The technology is able to detect, with relatively high accuracy, whether a person is currently wearing a device on their body, such as whether an earbud is being worn in an ear. Accuracy is enhanced by the use of a capacitive component that is inserted into the ear, which permits the component to maintain a consistent distance from the skin surface inside the ear. Accuracy may be further enhanced by the component's geometry, which provides a relatively large surface area despite the small form factor of the device. Different types of sensors may additionally be used for on-body detection, which may further reduce false positives. Accurate on-body detection may result in longer battery life because, among other reasons, the earbud may enter a standby state, or otherwise decrease its power usage when it is not being worn. In addition, user experience may be improved by routing audio to the most appropriate device. User experience may be further improved by detecting when the earbud is worn incorrectly and providing instructions to the user to help the user adjust the earbud.

<FIG> and <FIG> illustrate an example device, in particular, an earbud <NUM>. <FIG> shows the earbud <NUM> in a position wherein it is not being worn inside a user's ear <NUM>, and <FIG> shows the earbud <NUM> at a position wherein it is being worn inside ear <NUM>. By way of example, when being worn inside ear <NUM>, at least a portion of the earbud <NUM> may be surrounded by skin of the ear <NUM>. The earbud <NUM> may be wireless in that it does not require a wired connection for use. For instance, the earbud <NUM> may receive signals wirelessly such as from a music player, phone, or other device to perform a number of functions, such as to generate output, to communicate with other devices, to be charged, etc. The earbud <NUM> may form a pair with another earbud, such as earbud <NUM> shown in <FIG> and <FIG>. In some instances, the earbuds <NUM> and <NUM> may be truly wireless, where the pair of earbuds <NUM>, <NUM> are configured to connect to an audio source wirelessly, with no wire between the earbuds <NUM>, <NUM>.

Referring to <FIG>, the earbud <NUM> may include a housing <NUM>, which contains and supports various electronic and/or mechanical components of the earbud <NUM>. The housing <NUM> may be made of any of a number of materials. For instance, the housing <NUM> may at least partially be made of a non-conductive material, such as plastic, ceramic, etc. In some instances, the housing <NUM> may at least partially be made of a non-permeable material that protects components inside the housing <NUM> from contaminants in the environment.

The earbud <NUM> may include physical features that allow the earbud <NUM> to securely and comfortably fit in the ear <NUM>. For example as shown in <FIG>, the earbud <NUM> may include a cap <NUM> attached to the housing <NUM>. For example, the cap <NUM> may be attached to one end of the housing <NUM>. In some instances, the cap <NUM> may have at least one opening <NUM> such that sound from inside the earbud <NUM> may travel through the opening <NUM> to reach outside of the earbud <NUM>. The cap <NUM> may be made of any of a number of materials. For instance, the cap <NUM> may at least partially be made of a flexible, non-conductive material, for example, a polymeric material such as rubber or silicone. The cap <NUM> may be configured to provide a snug fit for the portion of the earbud <NUM> inserted into the ear <NUM>, such as by changing shape. Flexibility and dimensions of the cap <NUM> may further accommodate differences in ear anatomy and personal preferences on how to wear the earbud <NUM>. In some instances, the cap <NUM> may also be configured to provide sound occlusion with respect to sounds originating outside of the earbud <NUM>.

The earbud <NUM> may further include physical features that provide additional mechanical support. For example and as shown in <FIG>, the earbud <NUM> may further include a support <NUM> attached to the housing <NUM>. The support <NUM> may be attached to one end of the housing <NUM>, such as on the same end as the cap <NUM>. The cap <NUM> may additionally or alternatively be attached to the support <NUM>. In some examples, at least part of the support <NUM> may be attached to an inside surface of the housing <NUM> or embedded in the housing <NUM>. As also shown in <FIG>, the support <NUM> may be shaped like a snout of the earbud <NUM> and configured to fit inside an ear. For example, the support <NUM> may have a tubular shape. In some instances, the support <NUM> may be configured as a sound port for the earbud <NUM> such that sound from inside the earbud <NUM> may travel through one or more openings in the support <NUM> to reach outside of the earbud <NUM>. The support <NUM> may be made of any of a number of materials. For instance, the support <NUM> may at least partially be made of a conductive material, such as a metal or an alloy.

Referring to <FIG>, when the earbud <NUM> is being worn by the user, the cap <NUM> and the support <NUM> may be partially or fully inserted into the ear <NUM>. For instance, the cap <NUM> may be in direct contact with a skin surface <NUM> inside the ear <NUM>, such as a skin surface that is part of the ear canal <NUM>. When inserted into the ear <NUM>, the flexible material of the cap <NUM> may change its shape to provide a secure and comfortable fit.

As shown in <FIG>, while being worn, an outside surface of the support <NUM> may be positioned at a distance d1 from the skin surface <NUM> inside the ear <NUM>. The distance d1 may vary, for example within a range, depending on how the earbud <NUM> is being worn, the flexibility of cap <NUM>, the user's anatomy, and the user's preferences when wearing the earbud (e.g., how far the user prefers to insert the earbud into ear). However, the range may be relatively small because the cap <NUM> is configured to ensure a consistent fit despite differences in anatomy and preference. By way of example, the cap <NUM> may be configured with dimensions and flexibility that allows it to change shape within a predetermined range. For instance, the predetermined range may be set between a predetermined diameter for a relatively narrow ear canal and a predetermined diameter for a relatively wide ear canal. Further, the cap <NUM> may be configured to require a minimum level of compressive force against the ear canal to provide a secure fit. As such, to achieve the minimum level of compressive force, a user with a wider ear canal may want to push the earbud <NUM> further inside the ear than a user with a narrower ear canal. As such, the range for d1 may be relatively small.

Still further, due to the tubular shape of the support <NUM> that roughly corresponds to the tubular shape of the ear canal <NUM>, the support <NUM> may have a relatively large surface area A1 that is about a distance d1 from the skin surface <NUM> inside the ear <NUM>. In contrast, due to the small factor of the earbud <NUM>, it may be impracticable for another conductive component inside housing <NUM> to have a similar surface area. Even in instances where another conductive component inside housing <NUM> may be configured to have a surface area that is comparable to the surface area A1, points within the surface area may have very different distances to the ear <NUM>.

<FIG> illustrates some example components of the earbud <NUM>. As shown, various components may be housed inside the housing <NUM>. For example, a circuit board <NUM>, such as a printed circuit board ("PCB") may be provided in the housing <NUM>. The circuit board <NUM> may provide grounding for other components of the earbud <NUM>. The circuit board <NUM> may include any of a number of circuits configured to perform any of a number of functions, such as processing information, generating audio, communicating, charging, etc. As another example, a battery <NUM> may be provided in the housing <NUM>. For instance, the battery <NUM> may be charged, store energy, and provide energy to other components of the earbud <NUM>.

A speaker <NUM> may be provided in the housing <NUM>. The speaker <NUM> may include various components, such as metallic frame, metallic yoke, magnets, coils, amplifiers, diaphragms, and other circuit elements configured to receive analog and/or digital audio signals, and convert these audio signals into sound waves that can be perceived by the ear. For example, the speaker <NUM> may receive the audio signals from processors of the earbud <NUM>, or from a paired device. In some examples, received audio signals may be processed by circuit elements in the speaker <NUM> and the circuit board <NUM>, such as by filters, amplifiers, etc. The speaker <NUM> may be used to play music, emit audio for multimedia files, for voice calls, for translated speech, etc..

As still another example, a diode <NUM> may be provided inside the housing <NUM> to protect the electronic components from voltage spike due to static charges. For example, because of the structure and position of the capacitive sensor disposed along support <NUM>, the sensor may be more susceptible to static charges than the other components such as housing <NUM>, circuit board <NUM>, battery <NUM>, and speaker <NUM>. For instance, static charges from the cap <NUM>, which is not inside the housing <NUM>, may be transferred to the support <NUM>. Further, the support <NUM> may collect additional static charges, such as from skin of the user, in instances where the support <NUM> is at least partially exposed by the cap <NUM>, for example through the opening <NUM>. Such static charges may cause damage to the support <NUM>, and when transferred to other components inside the housing <NUM>, may also cause damage to these other components. In this regard, the diode <NUM> may be a transient-voltage-suppression diode. For instance, the support <NUM> may be connected to a ground on the circuit board <NUM> through the diode <NUM>.

As discussed further below, the earbud <NUM> may include various sensors. For example, an optical sensor <NUM> may be provided inside the housing <NUM>. As an example, the optical sensor <NUM> may be an infrared (IR) sensor. For instance, the optical sensor <NUM> may be configured to detect whether the earbud <NUM> is being worn based on measuring changes in received electromagnetic radiation, such as IR radiation. However, in some instances, the optical sensor <NUM> may falsely detect other events as the earbuds being worn. Such instances may include when a user touches the earbud <NUM> with a hand, when the earbud <NUM> is being placed inside a pocket, when contaminants such as dirt or oil covers a lens, when a lens of the optical sensor <NUM> has been scratched, etc..

In this regard, a capacitive sensor may be further provided in the earbud <NUM> for detecting whether the earbud <NUM> is being worn. The capacitive sensor may include one or more electrodes. Due to the small form factor of the earbud <NUM>, conductive components in the one or more of the components described in <FIG> may be used as the electrodes for the capacitive sensor. For instance, <FIG> and <FIG> show example circuit diagrams for an example capacitive sensor <NUM>. <FIG> shows an example circuit diagram when the earbud <NUM> is not being worn, and <FIG> shows an example circuit diagram when the earbud <NUM> is being worn. Although <FIG> and <FIG> show a few circuit elements for simplicity, the capacitive sensor <NUM> may additionally include any of a number of other circuit elements.

Referring to <FIG> and <FIG>, the capacitive sensor <NUM> may include a first electrode <NUM>, a second electrode <NUM>, and a detector <NUM>. The first electrode <NUM> and the second electrode <NUM> may be connected in series, and when worn, through the ear and body which is essentially conductive. In one aspect, the first electrode <NUM> may include the support <NUM>, and the second electrode <NUM> may include one or more conductive components inside the housing <NUM>. For instance, in the example shown, the second electrode <NUM> includes one or more conductive components of the circuit board <NUM>, one or more conductive components of the battery <NUM>, and one or more conductive components of the speaker <NUM>. Including more conductive components in the second electrode <NUM> may increase a total capacitance of the second electrode <NUM>, and in turn may increase the combined capacitance measured by the capacitive sensor <NUM>, resulting in larger, more detectable capacitance values. Each of electrodes <NUM>, <NUM> may be connected to a common ground <NUM>, such as via a wire, a trace, a flex, etc. For example, the ground <NUM> may be provided on the circuit board <NUM>. In this regard, by using components already existing in the earbuds <NUM> for capacitive sensing, the capacitive sensor <NUM> may save more space and be more cost efficient.

Further as shown, the detector <NUM> may be configured to generate a current (indicated by an arrow) passing through the circuit, such as an AC current or DC current. The detector <NUM> may be further configured to measure the currents, and determine capacitances based on the measured currents. In this regard, the detector <NUM> may include circuitry that is part of a processing chip or chipset, and may include one or more processors. For instance, since the first electrode <NUM> and the second electrode <NUM> are shown connected in series, the current may have a waveform before passing through the first electrode <NUM> and the second electrode <NUM>, and a different waveform after passing through the first electrode <NUM> and the second electrode <NUM>. Based on the changes, the detector <NUM> may measure a combined capacitance for the circuit including the first electrode <NUM> and the second electrode <NUM>.

When the earbud <NUM> is far away from the ear <NUM> as shown in <FIG>, the first electrode <NUM> may be more than a predetermined distance away from the ear <NUM>, and the second electrode <NUM> may be more than a second predetermined distance away from the ear <NUM>. As such, capacitances of the first electrode <NUM> and/or second electrode <NUM> may not be affected by the ear <NUM>. For example, a first capacitance C1 may have a value C_support for the first electrode <NUM>, a second capacitance C2 may have value C_PCB + C_battery + C_speaker for the second electrode <NUM>, so that the capacitive sensor <NUM> measures a combined capacitance C_capsenseor = C1*C2/(C1+C2).

Based on the capacitance values C1, C2, one or more processors of the detector <NUM> may detect that the earbud <NUM> is not being worn. For instance, the one or more processors may compare C_capsensor with a predetermined threshold capacitance, and detect that the earbud <NUM> is not being worn based on C_capsensor not meeting the predetermined threshold capacitance.

Referring to <FIG>, when the earbud <NUM> is worn in the ear <NUM>, the first electrode <NUM> may come within the predetermined distance from the ear <NUM> and/or the second electrode <NUM> may come within the second predetermined distance from the ear <NUM>. For example, the first electrode <NUM> may be at a distance d1 shown in <FIG>. As such, capacitances of the first electrode <NUM> and/or second electrode <NUM> may be affected by the ear <NUM>. For instance, a portion of the current (indicated by dotted arrow) from detector <NUM> may be diverted through the ear <NUM> to a virtual ground <NUM> inside the user's body. As such, detector <NUM> may measure that the combined capacitance formed by the first capacitance C1 and the second capacitance C2 have changed values than the example situation shown in <FIG>.

Based on the capacitance values C1, C2, one or more processors of the detector <NUM> may detect that the earbud <NUM> is being worn. For instance, the one or more processors may compare C_capsensor with the predetermined threshold capacitance, and detect that the earbud <NUM> is being worn based on C_capsensor meeting the predetermined threshold capacitance.

As shown and described earlier with respect to <FIG>, the support <NUM> provides a more consistent, and smaller distance d1 to the user's ear <NUM> than other components of the earbud <NUM>, including the circuit board <NUM>, the battery <NUM>, and the speaker <NUM>. Further, due to the small factor of the earbud <NUM>, using an additional component inside the housing <NUM> as the sensing electrode may not achieve the same small distance as the support <NUM>. Moreover, as discussed earlier, the support <NUM> may provide a larger surface area A1 shown in <FIG> than other components of the earbud <NUM>, and the surface area A1 may also maintain a more consistent distance from the ear <NUM> when being worn than other components.

Since capacitance varies as a function of distance and as a function of surface area, including capacitive measurement at support <NUM> for in-ear detection may provide a more reliable detection.

Detection using capacitance measurements including capacitance at the first electrode <NUM> may be further advantageous because it is less likely to produce false positives. For instance, while the user may touch various portions of the housing <NUM> with hands, once inserted into the ear <NUM>, the cap <NUM> and portions of the housing <NUM> near the support <NUM> are likely not accessible to the user's hand. In some instances, even while the user is adjusting the earbud <NUM> in the ear <NUM>, because support <NUM> is a pivoting point, there would be less variation in distance and surface area, thus resulting in more reliable capacitance measurements. Further, detection based on capacitance measurements including the capacitance at the first electrode <NUM> may additionally be advantageous because the support <NUM> is likely to come close to the ear <NUM> first, since it is the portion to be inserted. As such, using the first electrode <NUM> may allow earlier detection.

In another aspect, capacitance measurements including capacitance at the first electrode <NUM> may be further used for detecting whether the earbud <NUM> is being worn correctly. For instance, if the cap <NUM> is removed from the earbud <NUM>, support <NUM> may come in direct contact with the skin surface <NUM> inside the ear <NUM>. Since combined capacitance of the capacitive sensor <NUM> may be affected to a greater extent by the user's body with direct contact (than indirect contact through the cap <NUM>), a higher combined capacitance may be measured by the detector <NUM>. As such, the one or more processors may determine, for example based on detecting that the combined capacitance C_capsensor meeting a predetermined high threshold capacitance, that the earbud <NUM> is being worn without the cap <NUM>. For example, C1 may be shorted by direct contact with skin such that C_capsensor = C2. In some instances, removing the cap <NUM> may result in poorer sound quality or discomfort to the ear. In this regard, the one or more processors may be configured to generate an output instructing the user to put the cap <NUM> back on.

<FIG> shows another example circuit diagram illustrating another example capacitive sensor <NUM>. Example capacitive sensor <NUM> may include many of the features of example sensor <NUM>, such as first electrode <NUM> and second electrode <NUM>, details of which are omitted. As shown, the capacitive sensor <NUM> may further include diode <NUM> connected in parallel with the detector <NUM> to protect the detector <NUM> from electrostatic discharge. As mentioned earlier, static charges (indicated by dashed arrow) may be transferred from the user to the support <NUM>, and in turn to the detector <NUM>. The excess current from the static charges may be shunted by the diode <NUM> when the induced voltage exceeds the avalanche breakdown potential of the diode <NUM>. Although the examples of <FIG>, <FIG>, and <FIG> include two electrodes, in other examples the device may include additional electrodes. In such cases the combined capacitance may be determined further based on capacitance of the additional electrodes.

<FIG> is a functional block diagram of a pair of earbuds <NUM>, <NUM> in which the features described herein may be implemented. It should not be considered as limiting the scope of the disclosure or usefulness of the features described herein. For example as shown, the earbud <NUM> may contain one or more processors <NUM>, memory <NUM> and other components typically present in general purpose computing devices, and the earbud <NUM> may similarly contain one or more processors <NUM>, memory <NUM> and other components typically present in general purpose computing devices. The earbud <NUM> may similarly contain battery <NUM>, speaker <NUM>,.

Memories <NUM>, <NUM> can store information accessible by the one or more processors <NUM>, <NUM>, including instructions <NUM>, <NUM>, that can be executed by the one or more processors <NUM>, <NUM>. Memories <NUM>, <NUM> can also include data <NUM>, <NUM> that can be retrieved, manipulated or stored by the processors <NUM>, <NUM>. The memories can be of any non-transitory type capable of storing information accessible by the processor, such as a hard-drive, memory card, ROM, RAM, DVD, CD-ROM, write-capable, and read-only memories.

The instructions <NUM>, <NUM> can be any set of instructions to be executed directly, such as machine code, or indirectly, such as scripts, by the one or more processors. In that regard, the terms "instructions," "application," "steps" and "programs" can be used interchangeably herein. The instructions can be stored in object code format for direct processing by a processor, or in any other computing device language including scripts or collections of independent source code modules that are interpreted on demand or compiled in advance.

Data <NUM>, <NUM> can be retrieved, stored or modified by the one or more processors <NUM>, <NUM> in accordance with the instructions <NUM>, <NUM>. For instance, although the subject matter described herein is not limited by any particular data structure, the data can be stored in computer registers, in a relational database as a table having many different fields and records, or XML documents. The data can also be formatted in any computing device-readable format such as, but not limited to, binary values, ASCII or Unicode. Moreover, the data can comprise any information sufficient to identify the relevant information, such as numbers, descriptive text, proprietary codes, pointers, references to data stored in other memories such as at other network locations, or information that is used by a function to calculate the relevant data.

The one or more processors <NUM>, <NUM> can be any conventional processors, such as a commercially available CPU. Alternatively, the processors can be dedicated components such as an application specific integrated circuit ("ASIC") or other hardware-based processor. Although not necessary, the earbuds <NUM>, <NUM> may include specialized hardware components to perform specific computing processes, such as decoding video, matching video frames with images, distorting videos, encoding distorted videos, etc. faster or more efficiently.

Although <FIG> functionally illustrates the processor, memory, and other elements of earbuds <NUM>, <NUM> as being within the same block, the processor, computer, computing device, or memory can actually comprise multiple processors, computers, computing devices, or memories that may or may not be stored within the same physical housing. For example, the memory can be a hard drive or other storage media located in housings different from that of the earbuds <NUM>, <NUM>. Accordingly, references to a processor, computer, computing device, or memory will be understood to include references to a collection of processors, computers, computing devices, or memories that may or may not operate in parallel.

Further as shown in <FIG>, earbuds <NUM>, <NUM> may include one or more user inputs, such as user inputs <NUM>, <NUM> respectively. For instance, user inputs may include mechanical actuators, soft actuators, periphery devices, sensors, and/or other components. Examples of sensors in inputs <NUM>, <NUM> may include vibration sensors, such as microphones, touch sensors, such as capacitive or optical sensors, etc. For example, users may be able to control various audio characteristics using the user inputs <NUM>, <NUM>, such as turning audio on and off, adjusting volume, etc..

Earbuds <NUM>, <NUM> may include one or more outputs devices, such as output devices <NUM>, <NUM> respectively. For instance, output devices may include one or more speakers, transducers or other audio outputs, a user display, a haptic interface or other tactile feedback that provides non-visual and non-audible information to the user. For example, speakers in output devices <NUM>, <NUM> may be used to play music, emit audio for navigational or other guidance, for multimedia files, for voice calls, for translated speech, etc..

Earbuds <NUM>, <NUM> may include one or more sensors, such as sensors <NUM>, <NUM> respectively. For instance, sensors <NUM>, <NUM> may include capacitive sensors, such as capacitive sensors <NUM>, <NUM>. Sensors <NUM>, <NUM> may also each include optical sensors, such as optical sensors <NUM>, <NUM>. Other examples of sensors may further include an Inertial Measurement Unit ("IMU"), a barometer, a vibration sensor, a heat sensor, a radio frequency (RF) sensor, a magnetometer, and a barometric pressure sensor. Additional or different sensors may also be employed.

To obtain information from and send information to each other, as well as to other remote devices, earbuds <NUM>, <NUM> may each include a communication module, such as communication modules <NUM>, <NUM> respectively. The communication modules may enable wireless network connections, wireless ad hoc connections, and/or wired connections. Via the communication modules <NUM>, <NUM>, the earbuds <NUM>, <NUM> may establish communication links, such as wireless links. The communication modules <NUM>, <NUM> may be configured to support communication via cellular, LTE, <NUM>, WiFi, GPS, and other networked architectures. The communication modules <NUM>, <NUM> may be configured to support Bluetooth®, Bluetooth LE, near field communications, and non-networked wireless arrangements. The communication modules <NUM>, <NUM> may support wired connections such as a USB, micro USB, USB type C or other connector, for example to receive data and/or power from a laptop, tablet, smartphone or other device.

The earbuds <NUM>, <NUM> may each include one or more internal clocks <NUM>, <NUM>. The internal clocks may provide timing information, which can be used for time measurement for apps and other programs run by the computing devices, and basic operations by the computing devices, sensors, inputs/outputs, GPS, communication system, etc..

Using the communication modules <NUM>, <NUM>, earbuds <NUM>, <NUM> may communicate with other devices in a system via a network. For instance, <FIG> is a pictorial diagram illustrating an example system <NUM> in which the features described herein may be implemented. The system <NUM> may include the earbuds <NUM>, <NUM>, computing devices <NUM>, <NUM>, <NUM>, and a storage system <NUM>. As shown, the earbuds <NUM>, <NUM>, computing devices <NUM>, <NUM>, <NUM>, and storage system <NUM> can each be at different nodes of a network <NUM> and capable of directly and indirectly communicating with other nodes of network <NUM>. Although only a few computing devices are depicted in <FIG>, it should be appreciated that a typical system can include a large number of connected computing devices, with each different computing device being at a different node of the network <NUM>.

The network <NUM> and intervening nodes described herein can be interconnected using various protocols and systems, such that the network can be part of the Internet, World Wide Web, specific intranets, wide area networks, or local networks. The network can utilize standard communications protocols, such as Ethernet, WiFi and HTTP, protocols that are proprietary to one or more companies, and various combinations of the foregoing. Although certain advantages are obtained when information is transmitted or received as noted above, other aspects of the subject matter described herein are not limited to any particular manner of transmission of information.

Each of the computing devices <NUM>, <NUM>, <NUM> may be configured similarly to the earbuds <NUM>, <NUM>, with one or more processors, memory and instructions as described above. For instance, computing devices <NUM> and <NUM> may each be a client device intended for use by a user, such as user, and have all of the components normally used in connection with a personal computing device such as a central processing unit (CPU), memory (e.g., RAM and internal hard drives) storing data and instructions, user inputs and/or outputs, sensors, communication module, positioning system, clock, etc. For example, communication modules of computing devices <NUM>, <NUM> may similarly include one or more antennas for transmitting and/or receiving signals, such as Bluetooth® signals, and may also be configured to measure signal strengths of communication links. As another example, computing devices <NUM>, <NUM> may have the same and/or different types of user inputs and/or outputs as earbuds <NUM>, <NUM>, such as a screen or touchscreen for displaying texts, images, videos, etc. As yet another example, computing device <NUM> may be a server computer and may have all of the components normally used in connection with a server computer, such as processors, and memory storing data and instructions.

The computing devices <NUM>, <NUM>, and <NUM> may each comprise a full-sized personal computing device, or may alternatively comprise mobile computing devices capable of wirelessly exchanging data with a server over a network such as the Internet. For example, computing device <NUM> may be a mobile device, such as a mobile phone as shown in <FIG>, or some other mobile device such as a wireless-enabled PDA. As another example, computing device <NUM> may be a laptop computer as shown in <FIG>, or some other computing device such as a desktop computer, a tablet, or other smart device that is capable of obtaining information via communication links. In other examples (not shown), system <NUM> may additionally or alternatively include wearable devices, such as a smartwatch, a head mount device, etc..

As with memories <NUM>, <NUM>, storage system <NUM> can be of any type of computerized storage capable of storing information accessible by one or more of the earbuds <NUM>, <NUM>, and computing devices <NUM>, <NUM>, <NUM>, such as a hard-drive, memory card, ROM, RAM, DVD, CD-ROM, write-capable, and read-only memories. In addition, storage system <NUM> may include a distributed storage system where data is stored on a plurality of different storage devices which may be physically located at the same or different geographic locations. Storage system <NUM> may be connected to the computing devices via the network <NUM> as shown in <FIG> and/or may be directly connected to any of earbuds <NUM>, <NUM>, and computing devices <NUM>, <NUM>, <NUM>.

Further to example systems described above, example methods are now described. Such methods may be performed using the systems described above, modifications thereof, or any of a variety of systems having different configurations. It should be understood that the operations involved in the following methods need not be performed in the precise order described. Rather, various operations may be handled in a different order or simultaneously, and operations may be added or omitted.

For instance, <FIG> shows an example flow diagram that may be performed by one or more processors, such as one or more processors <NUM> and/or <NUM>. For example, processors <NUM> and/or <NUM> may receive data and make various determinations as shown in the flow diagram. Referring to <FIG>, in block <NUM>, a combined capacitance is measured at a conductive support attached to a housing of an earbud. In block <NUM>, it is detected, based on the combined capacitance, whether the conductive support is within a predetermined distance from a skin surface inside an ear. In block <NUM>, it is determined, based on whether the conductive support is within the predetermined distance from the skin surface inside the ear, whether the earbud is inserted into the ear. In block <NUM>, the earbud is operated in a first mode based on determining that the earbud is inserted into the ear. Although not shown, for a pair of earbuds such as earbuds <NUM> and <NUM>, the two earbuds <NUM> and <NUM> may be operated in the same mode or different modes based on detecting whether both are inserted into the ear.

For instance, <FIG> shows an example flow diagram that may be performed by one or more processors, such as one or more processors <NUM> and/or <NUM>. For example, processors <NUM> and/or <NUM> may receive data and make various determinations as shown in the flow diagram. Referring to <FIG>, at block <NUM>, capacitive sensor data is received. For example, the capacitive sensor data may be a combined capacitance measurement including capacitance C1 of the first electrode <NUM> and capacitance C2 of the second electrode <NUM> shown in <FIG> or <FIG>. At block <NUM>, it is determined based on the capacitive sensor data whether the earbud(s) are being worn. For example, the processors <NUM> may compare the combined capacitance measurement to a predetermined threshold capacitance. If not, at block <NUM>, audio output is routed to another electronic device. For example, the processors <NUM> may determine that the combined capacitance measurement does not meet the predetermined threshold capacitance. For example, the processors <NUM> may send a message to another device such as device <NUM> to generate audio output. For instance, the processors <NUM> may send the message using communication modules <NUM> and/or <NUM> via network <NUM>.

If yes, at block <NUM>, IR sensor data is received. For example, the processors <NUM> may determine that the combined capacitance measurement meets the predetermined threshold capacitance. For example, IR sensor data may include changes in IR radiation received by the optical sensor <NUM>. At block <NUM>, it is determined based on IR sensor data whether the earbud(s) are being worn. For example, the processors <NUM> may compare the IR sensor data with a predetermined threshold value. If yes, at block <NUM>, audio output is routed to the earbud(s). For example, the processors <NUM> may control the speaker <NUM> to generate audio output. If not, at block <NUM>, audio output is routed to another electronic device.

In this regard, the use of two different types of sensors detecting whether the earbud(s) are being worn may reduce the number of false detections. For instance, sensing inaccuracies of the capacitive sensor may be caused by different factors as the IR sensor. For example, whereas IR sensors may have inaccurate detections resulting from hand touches, being placed inside a pocket, and contaminants and scratches on a lens, capacitive sensors may have inaccurate detections resulting from other factors, such as variations in separation distance, contact surface area, dielectric changes as a result of temperature variation, etc. Since it is less likely that both types of factors exist, it is less likely that both sensors will produce detection errors at the same time.

<FIG> shows another example flow diagram that may be performed by one or more processors, such as one or more processors <NUM> and/or <NUM>. For example, processors <NUM> and/or <NUM> may receive data and make various determinations as shown in the flow diagram. Referring to <FIG>, at block <NUM>, capacitive sensor data is received. At block <NUM>, it is determined based on the capacitive sensor data whether the earbud(s) are being worn. If not, at block <NUM>, the earbud(s) are controlled to remain in a standby mode. For example, the standby mode may be one in which the earbuds <NUM>, <NUM> operate using less power, such as having some of its functions turned off, and/or having sensing or communication capabilities turned to a lower frequency.

If yes, at block <NUM>, the earbud(s) are controlled to enter an active mode. For example, the active mode may be one in which the earbuds <NUM>, <NUM> are generating audio output, or sensing and/or communicating at a higher frequency than the standby mode. At block <NUM>, it is determined whether the earbud(s) are inserted incorrectly. For example, processors <NUM> may determine that the cap <NUM> is removed from the earbud <NUM> based on detecting a combined capacitance at the first electrode <NUM> meeting a predetermined high threshold capacitance. If yes, at block <NUM>, an output is generated to instruct the user to adjust the earbud(s). For example, processors <NUM> may control speaker <NUM> to generate an audio output instructing the user to adjust the earbud <NUM>. As another example, processors <NUM> may send a message to another device such as device <NUM> to generate an output instruction for the user, such as via a display or a speaker. If not, at block <NUM>, the earbud(s) remain in the active mode.

The technology is able to detect, with relatively high accuracy, whether a person is currently wearing a device on their body, such as an earbud in an ear. Accuracy is enhanced by the use of a capacitive component that is inserted into the ear, which permits the component to maintain a consistent distance from the skin surface inside the ear. Accuracy may be further enhanced by the component's geometry, which provides a relatively large surface area despite the small form factor of the device. Different types of sensors may additionally be used for on-body detection, which may further reduce false positives. Accurate on-body detection may result in longer battery life because, among other reasons, the earbud may enter a standby state, or otherwise decrease its power usage when it is not being worn. In addition, user experience may be improved by routing audio to the most appropriate device. User experience may be further improved by detecting when the earbud is worn incorrectly and providing instructions to the user to help the user adjust the earbud.

Claim 1:
A device (<NUM>, <NUM>), comprising:
a housing (<NUM>);
a speaker (<NUM>);
a battery (<NUM>);
a circuit board (<NUM>);
a conductive support (<NUM>) attached to the housing; and
one or more processors configured to:
measure a combined capacitance based on a combination of a first capacitance (C1) at a first electrode (<NUM>) including the conductive support and a second capacitance (C2) at a second electrode (<NUM>) at the housing, wherein the first and second electrodes are arranged and configured to be connected through an ear (<NUM>) when the conductive support is inserted into the ear;
detect, based on the combined capacitance, whether the conductive support is inserted into an ear; and
operate the device in a first mode based on detecting that the conductive support is inserted into the ear,
wherein the speaker, the battery, the circuit board, and the conductive support are connected to a common ground (<NUM>); and
wherein the second electrode includes one or more conductive components of the speaker, one or more conductive components of the battery, and one or more conductive components of the circuit board.