PATENT DOCUMENT

Publication Number: US-9118354-B2
Application Number: US-201113221642-A
Country: US
Kind Code: B2

Title: Electronic device with shared near field communications element

Abstract:
Electronic devices may be provided with near field communications capabilities. A near field communications antenna may be formed from multiple inductive components. The inductive components may include a speaker coil. One or more switches may be provided in the near field communications antenna to adjust the inductance of the near field communications antenna during different modes of operation. An audio circuit may be used to generate audio signals. A first transmitter may be used to transmit near field hearing aid signals through the near field communications antenna. A second transmitter may be used to transmit near field communications signals to external equipment such as near field communications point of sale equipment. Switching circuitry may be used to selectively couple the audio circuit, the first transmitter, and the second transmitter to the near field communications antenna.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a near field communications element; 
 a first radio-frequency transmitter configured to transmit first near field communications signals through the near field communications element; 
 a second radio-frequency transmitter configured to transmit second near field communications signals through the near field communications element; and 
 a circuit that couples the first and second radio-frequency transmitters to the near field communications element, wherein the first radio-frequency transmitter comprises a hearing aid compatibility transmitter configured to transmit the first near field communications signals to an external hearing aid, and wherein the circuit comprises switching circuitry for selectively coupling a selected one of the first and second radio-frequency transmitters to the near field communications element. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the second radio-frequency transmitter comprises a near field communications (NFC) transmitter configured to transmit the second near field communications signals to a point of sale terminal. 
     
     
       3. The electronic device defined in  claim 2  wherein the near field communications element comprises an adjustable near field communications element. 
     
     
       4. The electronic device defined in  claim 2  wherein the near field communications element comprises at least one speaker coil. 
     
     
       5. The electronic device defined in  claim 1  wherein the near field communications element includes at least two inductive components and at least one switch for bypassing at least one of the inductive components. 
     
     
       6. The electronic device defined in  claim 1  wherein the near field communications element includes at least one coil from a vibrator, wherein the vibrator is configured to create vibrations within the electronic device to signal the presence of an incoming telephone call. 
     
     
       7. The electronic device defined in  claim 1  wherein the near field communications element includes a first inductor, a second inductor, and a third inductor and includes at least two switches. 
     
     
       8. The electronic device defined in  claim 7  further comprising an audio circuit that produces audio signals, wherein the switching circuitry is configured to couple a selected one of the audio circuit, the first radio-frequency transmitter, and the second radio-frequency transmitter to the near field communications element. 
     
     
       9. The electronic device defined in  claim 1  further comprising audio circuitry, wherein the switching circuitry is interposed between the audio circuitry, the first radio-frequency transmitter, and the second radio-frequency transmitter and the near field communications element. 
     
     
       10. The electronic device defined in  claim 9  wherein the near field communications element includes a first inductor formed from a speaker coil. 
     
     
       11. The electronic device defined in  claim 10  wherein the near field communications element includes a second inductor that is connected to the first inductor. 
     
     
       12. The electronic device defined in  claim 11  further comprising control circuitry that generates control signals that direct the switching circuitry to couple a selected one of the audio circuitry, the first radio-frequency transmitter, and the second radio-frequency transmitter to the near field communications element. 
     
     
       13. The electronic device defined in  claim 12  wherein the near field communications element includes a switch and wherein the control circuitry is configured to control the switch to bypass the second inductor. 
     
     
       14. An electronic device, comprising:
 a near field communications antenna formed at least partly from a speaker coil; 
 a hearing aid compatibility transmitter that generates first radio-frequency signals that are transmitted to a hearing aid as near field electromagnetic signals through the near field communications antenna; 
 a near field communications transmitter that generates second radio-frequency signals that are transmitted to a point of sale terminal as near field electromagnetic signals through the near field communications antenna; and 
 switching circuitry with first and second configurations, wherein only the hearing aid compatibility transmitter transmits signals through the near field communications antenna in the first configuration, and wherein only the near field communications transmitter transmits signals through the near field communications antenna in the second configuration. 
 
     
     
       15. The electronic device defined in  claim 14  wherein the near field communications antenna includes at least one switch having an open position in which the near field communications antenna has a first inductance and a closed position in which the near field communications antenna has a second inductance. 
     
     
       16. The electronic device defined in  claim 15  further comprising:
 an audio circuit that provides audio signals to the speaker coil, wherein the switching circuitry is configured to couple the audio circuit to the speaker coil and configured to couple the hearing aid compatibility transmitter and the near field communications transmitter to the near field communications antenna. 
 
     
     
       17. An electronic device, comprising:
 a near field communications element formed from a speaker coil and an inductive structure and having a switch; 
 a first transmitter; 
 a second transmitter; 
 switching circuitry, wherein the switching circuitry is interposed between the first transmitter and the near field communications element, and wherein the switching circuitry is interposed between the second transmitter and the near field communications element; and 
 control circuitry that is configured to open and close the switch to adjust an inductance value associated with the near field communications element and that is configured to place the switching circuitry in at least a first configuration in which the first transmitter transmits near field radio-frequency signals to a hearing aid through the near field communications element and a second configuration in which the second transmitter transmits near field radio-frequency signals through the near field communications element to external near field communications equipment. 
 
     
     
       18. The electronic device defined in  claim 17  wherein the control circuitry is configured to adjust the inductance value to a first value when the switching circuitry is in the first configuration and is configured to adjust the inductance value to a second value that is different than the first value when the switching circuitry is in the second configuration.

Description:
This relates generally to wireless communications circuitry, and more particularly, to electronic devices that have wireless communications circuitry for supporting near field wireless communications. 
     Electronic devices often have wireless communications circuitry. For example, cellular telephones contain antennas and radio-frequency transceiver circuitry that is used in transmitting and receiving cellular telephone signals over relatively large distances (sometimes referred to as the “far field”). 
     Some electronic devices also have wireless circuitry that handles communications using “near field” electromagnetic coupling. In a near field wireless arrangement, wireless signals may be conveyed over a relatively short distance (e.g., a few centimeters or less). Near field wireless communications circuitry may be used for application such as wireless payments where it is desirable to limit the range of the wireless signal to enhance security. 
     Some hearing aids are provided with circuitry for receiving near field wireless signals. During operation, a hearing aid compatible (HAC) wireless devices may generate near field signals that are received by a nearby hearing aid. The use of HAC wireless devices may help hearing impaired users listen to audio content while temporarily bypassing the microphone in the hearing aid. This can be helpful in noisy environments in which background noise has the potential to overwhelm the audio content. 
     To ensure that a device can be used both by hearing impaired users and by a users who are not hearing impaired, electronic devices generally include speakers. As they produce sound, some speakers may emit near field electromagnetic signals that are detectable by hearing aids with circuitry for receiving near field wireless signals. 
     Wireless devices with small sizes are increasingly popular. To ensure that a wireless device has a compact size, it may be desirable to eliminate unnecessary components. Minimizing device size in this way can be challenging, particularly when attempting to accommodate user demand near field communications capabilities, speakers, and HAC functionality. 
     It would therefore be desirable to be able to provide wireless devices with improved near field communications capabilities. 
     SUMMARY 
     Electronic devices may be provided with near field communications capabilities. A near field communications element may serve as an antenna for transmitting near field communications signals to external equipment. The external equipment may include hearing aids with near field communications capabilities, point of sale equipment, security card readers, and other equipment that receives near field communications signals. 
     The near field communications element may be formed from multiple inductive components. The inductive components may include a speaker coil or a coil associated with other electromagnetic transducer structures. Inductive components such as inductors formed from loops of conductor on a dielectric substrate may also be used in the near field communications element. 
     One or more switches may be provided in the near field communications antenna to adjust the inductance of the near field communications antenna during different modes of operation. When a first inductance value is desired, the switches can bypass unneeded inductive components. When a second inductance value that is greater than the first inductance value, the switches can be configured to switch appropriate inductive components into use in the near field communications element. 
     An audio circuit may be used to generate audio signals. A first transmitter may be used to transmit near field hearing aid signals through the near field communications element. A second transmitter may be used to transmit near field communications signals to external equipment such as near field communications point of sale equipment. Switching circuitry may be used to selectively couple the audio circuit, the first transmitter, and the second transmitter to the near field communications element. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device of the type that may be provided with near field communications capabilities in accordance with an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of a system in which electronic equipment communicates using near field communications in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of illustrative wireless communications circuitry in which a first transmitter such as a near field communications transmitter and a second transmitter such as a transmitter used for communicating with a hearing aid are coupled to a shared near field communications element in a wireless electronic device in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram of illustrative wireless communications circuitry in which first and second transmitters share an adjustable near field communications element in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative speaker showing how a coil in the speaker may surround a moving magnet in accordance with an embodiment of the present invention. 
         FIG. 6  is a diagram of wireless near field communications circuitry in which an adjustable near field communications element is formed from a circuit network with three inductors and two switches in accordance with an embodiment of the present invention. 
         FIG. 7  is a diagram of wireless near field communications circuitry in which an audio circuit and two near field communications transmitter circuits are coupled to an adjustable near field communications element having two inductors an a switch in accordance with an embodiment of the present invention. 
         FIG. 8  is a table showing how the inductance of an adjustable near field communications element of the type shown in  FIG. 6  may be adjusted to accommodate three modes of operation in accordance with an embodiment of the present invention. 
         FIG. 9  is a table showing how the inductance of an adjustable near field communications element of the type shown in  FIG. 7  may be adjusted to accommodate two modes of operation in accordance with an embodiment of the present invention. 
         FIG. 10  is a diagram of illustrative near field communications circuitry in which a transducer driver such as an audio circuit or a circuit for controlling a vibrator or other actuator and one or more wireless transceiver circuits may be coupled to a near field communications element such as an inductor that forms part of a transducer in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in cellular telephone bands, wireless local area network bands, and other wireless communications bands. The wireless communications circuitry may also include wireless circuitry for communicating over short distances using near field electromagnetic coupling. Wireless communications using near field coupling are sometimes referred to as near field communications. 
     Near field communications (NFC) may be used to convey any suitable information. Examples of applications of near field communications include wireless payments, security devices such as wireless keys, wireless identification cards, etc. Near field electromagnetic coupling may also be used to convey information between a device and external equipment such as a hearing aid. When equipment uses near field electromagnetic signals to convey hearing aid audio signals, the equipment is sometimes said to provide hearing aid compatibility (HAC) functions. 
     A device such as device  10  of  FIG. 1  may support one or more different types of near field communications schemes. In a typical scheme, signals that are to be transmitted may be generated using a transmitter circuit in device  10 . An inductor or other near field communications element (sometimes referred to as a near field communications antenna or near field communications antenna structures) may be used to radiate (transmit) corresponding near field electromagnetic signals. These signals may be received by external equipment. For example, near field communications signals that are associated with a wireless payment transaction may be received by near field communications equipment in a point of sale terminal. Near field signals that are associated with hearing aid information may be received by a hearing aid (e.g., using an inductor in a hearing aid). 
     To accommodate multiple types of near field communications, multiple transmitters may be coupled to a shared inductor or other near field communications element. The shared near field communications element may, if desired, be adjusted during operation. In some modes of operation, for example, the inductor or other shared near field communications element may be adjusted to exhibit a given inductance value. In one or more other modes of operation, the inductor or other shared near field communications element may be adjusted to exhibit one or more additional inductance values. Tuning the shared near field communications element in this way may help reduce or eliminate the need for multiple independent near field communications elements in device  10 . 
     Electronic device  10  of  FIG. 1  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wristwatch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a cellular telephone, a media player, etc. 
     Device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may, for example, be a touch screen that incorporates capacitive touch electrodes. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electronic ink elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover glass layer may cover the surface of display  14 . Portions of display  14  within rectangular region  20  may correspond to the active part of display  14 . In active display region  20 , an array of image pixels may be used to display images for a user. Portions of display  14  such as peripheral regions surrounding rectangular active region  20  may be inactive and may be devoid of image pixel structures. 
     The cover glass layer that covers display  14  may have openings such as a circular opening for button  18  and a speaker port opening such as speaker port opening  16  (e.g., for an ear speaker for a user). Openings  16  and  18  may, for example, be formed in the inactive portion of display  14 . Device  10  may also have other openings (e.g., openings in display  14  and/or housing  12  for accommodating volume buttons, ringer buttons, sleep buttons, and other buttons, openings for an audio jack, data port connectors, removable media slots, etc.). For example, the housing at the lower end of device  10  or other suitable portion of device  10  may have openings to form microphone port  21  and speaker port  23 . 
     Antennas for far field and near field communications may be located may be located along the edges of device  10 , on the rear or front of device  10 , as extending elements or attachable structures, or elsewhere in device  10 . Near field communications antennas (near field communications elements) may be formed using any type of structure that emits near field electromagnetic signals. Near field communications elements based on inductors are sometimes described herein as examples. This is merely illustrative. Any suitable conductive structures that emit sufficient near field radiation to couple with corresponding near field communications structures in external equipment may be used if desired. 
       FIG. 2  is a schematic diagram of a system environment in which near field electromagnetic coupling is used to communicate signals between device  10  and external equipment  30 . Device  10  may be a cellular telephone, a tablet computer, a laptop computer, a wristwatch device or other miniature or wearable device, a handheld device or other portable device, or other suitable electronic equipment. External equipment  30  may be a hearing aid, a near field communications point of sale terminal for handling wireless payments, a near field communications reader associated with security equipment (e.g., a door opener, a badge reader, etc.), or other external equipment. In a typical system environment, device  10  may sometimes communicate with one type of near field communications equipment and may, at other times, communicate with one or more other types of near field communications equipment. For example, a user of device  10  may place device  10  near to a point of sale terminal when it is desired to make a wireless payment, may place device  10  near a door lock when it is desired to obtain access to a building, may place device  10  near a security card reader when it is desired to authenticate to a computer system, and may place device  10  near to a hearing aid when it is desired to communicate with the hearing aid using near field communications. 
     As shown in  FIG. 2 , electronic device  10  and external equipment  30  may include control circuitry  26  and  36 . Control circuitry  26  and  36  may include microprocessors, microcontrollers, digital signal processors, application-specific integrated circuits, storage such as volatile and non-volatile memory (e.g., hard drives, solid state drives, random-access memory, etc.), and other storage and processing circuitry. 
     Device  10  and external equipment  30  may also include transceiver circuitry such as transceiver circuitry  24  and  34 . Transceiver circuitry  24  and  34  may include one or more radio-frequency transmitters, one or more radio-frequency receivers, both transmitters and receivers, or other suitable communications circuitry for generating radio-frequency signals for near field communications. With one illustrative arrangement, device  10  includes a transmitter (i.e., transceiver  24  is a transmitter) and equipment  30  includes a corresponding receiver (i.e., transceiver  34  is a receiver). This type of arrangement may be used to support unidirectional near field communications between device  10  an external equipment  30 . If desired, bidirectional near field communications may be supported. For example, transceiver  24  may include a transmitter and a receiver and transceiver circuitry  34  may include a transmitter and a receiver. Wireless near field communications signals  28  may, in general, be communicated from device  10  to equipment  30 , from equipment  30  to device  10 , or both from device  10  to equipment  30  and from equipment  30  to device  10 . 
     Device  10  and equipment  30  may include near field communications elements  22  and  32 . These structures, which are sometimes referred to as near field communications antennas may be formed form inductors or other structures (e.g., capacitors for capacitive coupling arrangements or networks of multiple components such as inductors and/or capacitors for forming tuned resonating circuits). The structures of near field communications elements  22  and  32  are capable of transmitting and/or receiving near-field-coupled radio-frequency electromagnetic fields. Examples in which near-field communications elements are formed from inductive components are sometimes described herein as an example. 
     An illustrative configuration that may be used for device  10  is shown in  FIG. 3 . As shown in  FIG. 3 , device  10  may include a near field communications element such as element  22 . Element  22  may be based on inductive structures (e.g., looped conductors that form one or more inductors). Terminal  46  may form a first terminal for element  22  and terminal  48  may form a second terminal for element  22 . 
     Wireless transceiver circuitry  24  may include multiple transceiver circuits. As an example, wireless circuitry  24  may includes a first transceiver circuit such as NFC transmitter  42  and a second transceiver circuit such as HAC transmitter  44 . Transmitter  42  may be used to transmit wireless payment information or other NFC data (e.g., non-hearing-aid information such as security card information, wireless lock information, payment information, etc.). Transmitter  44  may be used to transmit hearing aid signals (i.e., HAC audio signals). The audio signals that are transmitted by HAC transmitter  44  may contain audio for a voice telephone call, audio associated with playing back a media file such as a song, or other audio signals produced in connection with the operations of device  10 . First transmitter  42  and second transmitter  44  may be used to support different types of near field signaling schemes. For example, transmitter  42  may be used to support a wireless payment protocol or a security protocol, whereas transmitter  44  may be used to support HAC audio communications. Circuits  42  and  44  may be implemented using one or more integrated circuits. For example, circuit  42 , circuit  44 , and one or more integrated circuits in control circuitry  26  may be implemented using separate integrated circuits. If desired, circuit  42  and circuit  44  (and, optionally one or more control circuits within control circuitry  26 ) may be implemented using a common integrated circuit. 
     Circuit  40  may be used to couple multiple transceiver circuits such as transmitter  42  and transmitter  44  to shared near field communications element  22 . Circuit  40  may, for example, be a coupler that allows circuits  42  and  44  to operate simultaneously. Circuit  40  may also be implemented using switching circuitry that selectively couples either circuit  42  or circuit  44  to terminals  46  and  48 . This type of arrangement, which is sometimes described herein as an example, allows control circuitry  26  to transmit near field signals through shared near field communications element  22  using either circuit  42  or circuit  44 . Switching circuit configurations may also be used to selectively couple three or more transmitters to a near field communications element. 
     Path  50  may be used to convey one or more control signals between control circuitry  26  and switching circuitry  40 . When it is desired to transmit NFC signals with NFC transmitter  42  (e.g., for a wireless payment), control circuitry  26  may provide control signals to switching circuitry  40  via control path  50  that direct switching circuitry  40  to operate in a first (NFC) mode. In the NFC mode, NFC transmitter  42  may be coupled to near field communications element  22  and may be used in conveying NFC signals (e.g., wireless payment data or other information) to external equipment (e.g., a wireless point of sale terminal, etc.). When it is desired to transmit HAC signals with HAC transmitter  42  (e.g., to convey audio to an associated hearing aid), control circuitry  26  may provide control signals to switching circuitry  40  that direct switching circuitry  40  to operate in a second (HAC) mode. After placing switching circuitry  40  in the HAC configuration, HAC transmitter  44  may be used to convey HAC near field signals to external equipment such as a hearing aid using near field communications element  22 . Because a single near field communications element  22  is used (in this example), the hardware resources associated with supporting multiple types of near field communications may be minimized. 
     If desired, the properties of near field communications element  22  may be adjusted during operation of device  10 . For example, near field communications element  22  may be placed in different configurations to accommodate different types of near field communications. Consider, as an example, a scenario in which device  10  supports two different near field communications modes (e.g., a NFC communications mode for making wireless payments and an HAC communications mode for transmitting hearing aid audio signals). In response to determining that NFC communications are to be conveyed over near field communications element  22 , control circuitry  26  may place near field communications element  22  in a first configuration. In the first configuration, the near field communications element may, for example, exhibit a first set of electrical properties (e.g., a first inductance value). In response to determining that HAC communications are to be conveyed over near field communications element  22 , control circuitry  26  may place near field communications element  22  in a second configuration. In the second configuration, the near field communications element may, for example, exhibit a second set of electrical properties that are different than the first set of electrical properties (e.g., a second inductance value that is different than the first inductance value). Adjusting the properties of near field communications element  22  in this way may help device  10  accommodate communications with different types of external equipment. 
     An illustrative configuration that may be used for implementing an adjustable near field communications element in device  10  is shown in  FIG. 4 . In the example of  FIG. 4 , near field communications element  22  has been formed from multiple inductors. A first inductor may have an inductance of L 1  and a second inductor may have an inductance value of L 2 . The first and second inductors (in this example) are interconnected using switching circuitry such as switch SW. The state of switch SW may be controlled by control signals from control circuitry  26  that are conveyed to switch SW via control path  52 . In a first state, switch SW is open, so that terminals  54  and  56  are not electrically connected to each other through switch SW. In this first state, the inductance exhibited by near field communications element  22  across terminals  46  and  48  will be equal to the sum of inductance values L 1  and L 2  (i.e., the inductance of near field communications element  22  will be L 1 +L 2  do to the series connection of inductors L 1  and L 2 ). In a second state, switch SW is closed, so that terminals  54  and  56  are electrically shorted to each other through switch SW. This configuration for the switching circuitry in adjustable near field communications element  22  bypasses inductive component L 2 . With inductor L 2  bypassed, near field communications element  22  exhibits an inductance value of L 1  across terminals  46  and  48 . 
     As this example demonstrates, near field communications element  22  may be adjusted (tuned) between at least two different configurations. In the first configuration, element  22  may have a first inductance and in a second configuration element  22  may have a second inductance. Control circuitry  26  can place near field communications element  22  in an appropriate configuration depending on the type of near field communications that is desired. For example, when transmitter  42  is being used and transmitter  44  is inactive, control circuitry  26  can place near field communications element  22  in its first mode and when transmitter  44  is being used while transmitter  42  is inactive, control circuitry  26  can place near field communications element  22  in its second mode (as an example). 
     The conductive structures that make up near field communications element  22  may include wires, portions of a conductive housing structure associated with housing  12  of  FIG. 1 , patterned metal foil, conductive traces such as metal traces on a printed circuit or other dielectric substrate, or any other suitable conductive structures. In configurations in which near field communications element  22  includes inductive components, the conductive structures in near field communications element  22  may be formed from one or more loops (coils) of conductor. When coiled, the conductive lines in near field communications element  22  may form inductors such as inductors L 1  and L 2  of  FIG. 4 . 
     As an example, some or all of the conductive structures that are used in forming near field communications element  22  may be implemented using coils of metal traces on a dielectric substrate. If desired, some or all of the conductive structures in near field communications element  22  may be formed from coils of conductor (e.g., coiled wire) in a speaker. The speaker may be located in speaker port  16  or speaker port  23  of  FIG. 1  (as examples). An advantage of forming near field communications element  22  from at least part of a speaker coil in a speaker associated with speaker port  16  is that near field communications signals that are emitted from the upper half of device  10  tend to couple well into a hearing aid when a user holds device  10  against the user&#39;s ear that contains the hearing aid. 
     A cross-sectional side view of an illustrative speaker of the type that may be used in speaker port  23  (a speakerphone port) or speaker port  16  (an ear speaker port) is shown in  FIG. 5 . As shown in  FIG. 5 , speaker  58  may have a moving magnet such as magnet  66 . Magnet  66  and stationary coils  64  may be mounted within yolk (concentrator plate)  68 . Plate  68  may be formed from a ferromagnetic material such as iron. Magnet  66  may be a permanent magnet and may be affixed to speaker diaphragm  72  and stiffener  74 . The outer perimeter of diaphragm  72  may be supported by support structures  70 . When audio signals are applied to coils  64  via terminals  60  and  62 , magnetic fields are produced that cause magnet  66  and therefore the center of diaphragm  72  to move to create sound. The example of  FIG. 5  shows a moving magnet arrangement, but, if desired, speakers may be formed using different arrangements (e.g., moving coil configurations, etc.). The arrangement of  FIG. 5  is merely illustrative. 
     Some or all of the coils in a speaker such as coils  64  of speaker  58  in  FIG. 5  may be used in forming near field communications element  22 . For example, coils  64  of  FIG. 5  may be used in forming inductor L 1  of  FIG. 4 , inductor L 2  of  FIG. 4 , or both inductors L 1  and L 2  of  FIG. 4 . If coils  64  of  FIG. 5  are used to form both inductors L 1  and L 2 , an electrical connection may be made at an intermediate location along the length of coils  64  to form a tap point for switch SW. In configurations in which coils  64  are used to form L 1  or L 2  the remaining inductor (L 2  or L 1 ) may be formed using another speaker coil, using loops of conductor on a printed circuit board or other substrate, using a discrete inductor having coils surrounding a ferromagnetic element, or other suitable inductor structures. 
       FIG. 6  is a diagram that shows how an audio circuit may be coupled to near field communications element  22  in a configuration of the type in which at least a portion of near field communications element  22  is formed from a speaker coil inductor such as coils  64  of  FIG. 5 . As shown in  FIG. 6 , near field communications element  22  may have multiple inductive components such as inductors L 1 , L 2 , and L 3 . Switching circuitry such as switches SW 1  and SW 2  may be selectively configured by control circuitry  26  by issuing control commands SW 1 _E and SW 2 _E over control paths  52 . When control circuitry  26  turns off switches SW 1  and SW 2 , the inductance of near field communications element  22  will be equal to the sum of inductances L 1 , L 2 , and L 3 . Inductor L 3  may be bypassed by turning on switch SW 1  and turning off switch SW 2  (i.e., by asserting switch enable signal SW 1 _E and deasserting switch enable signal SW 2 _E). When inductor L 3  is bypassed in this way, the inductance of near field communications element  22  will be equal to the sum of inductances L 1  and L 2 . In scenarios in which it is desired to bypass both inductors L 2  and L 3 , switch SW 2  may be turned on. When SW 2  is turned on, the inductance of near field communications element  22  will be equal to L 1 . 
     Inductor L 1  may be implemented using a speaker coil (inductor) such as coils  64  of  FIG. 5 . Inductors L 2  and L 3  may be implemented using speaker coils or other inductive components in device  10  (e.g., loops of conductor on a printed circuit board or other substrate that form a near field communications antenna, etc.). 
     When it is desired to play audio signals through the speaker for a non-hearing impaired user of device  10 , control circuitry  26  can use switching circuitry  40  to couple audio circuitry  76  to the speaker (inductor L 1 ). Switch SW 2  may be turned on to bypass inductors L 2  and L 3 . 
     The audio that is played back for the user when audio circuitry  76  is active may include noise cancellation signals that are obtained from a microphone on a headset that is attached to device  10 . The localized noise associated with the noise cancellation signals will not be experienced by a user of a hearing aid when the hearing aid user is not using the headset. As a result, the user of the hearing aid might experience undesirable noise if the user of the hearing aid were to receiving a near field signal generated using audio circuitry  76  and inductor L 1 . This noise cancellation signal can be avoided by the user of the hearing aid by deactivating audio circuitry  76  and playing back the desired audio content (without a noise cancellation signal) for the user of the hearing aid using HAC transmitter  44  instead of audio circuitry  76  (as an example). 
     If desired, the inductance value of near field communications element  22  may be adjusted to optimize device  10  for HAC near field communications. As an example, switch SW 2  could be turned off and switch SW 1  could be turned on to adjust the inductance of near field communications element to L 1 +L 2  during HAC transmissions. During use of HAC transmitter  44 , control circuitry  26  can adjust switching circuitry  40  to couple HAC transmitter  44  to near field communications element  22 . 
     When it is desired to use NFC transmitter  42  (e.g., for handling a wireless payment transaction), control circuitry  26  may adjust switching circuitry  40  so that NFC transmitter  42  is coupled to near field communications element  22 . Control circuitry  26  may also adjust the inductance of near field communications element  22  to optimize element  22  for near field communications signals from NFC transmitter  42 . For example, control circuitry  26  may turn off switches SW 1  and SW 2  so that the inductance exhibited by near field communications element  22  is equal to the sum of inductances L 1 , L 2 , and L 3  (as an example). 
     If desired, near field communications element  22  may be provided with fewer adjustable inductance values. As shown in  FIG. 7 , for example, near field communications element  22  may have a switch such as switch SW. Switch SW may be controlled by control signals SW_E that are provided to switch SW from control circuitry  26  using control path  52 . Control circuitry  26  may place near field communications element  22  in a first mode having inductance L 1  by closing switch SW to bypass inductor L 2 . When it is desired to increase the inductance of near field communications element  22  to L 1 +L 2 , switch SW may be placed in its open position. 
     Control circuitry  26  may use path  50  to supply control signals to switching circuitry  40 . Switching circuitry  40  may be directed to couple audio circuitry  76  to element  22  when playing back audio (e.g., audio with noise cancellation) from audio circuitry  76  to a user who is not using a hearing aid. When a user of a hearing aid desires to listen to audio from device  10 , control circuitry  26  may use switching circuitry  40  to couple HAC transmitter  44  to near field communication element  22 . NFC transmitter  42  may be coupled to near field communications element  22  when it is desired to transmit NFC signals to external equipment (e.g., for NFC wireless payment transaction). 
       FIG. 8  is a table of illustrative inductance settings that may be used for near field communications element  22  in different modes of operation when using a device having circuitry of the type shown in  FIG. 6 . As shown in  FIG. 8 , the switching circuitry of near field communications element  22  may adjust the inductance of near field communications element  22  between a first value (L 1 ), a second value (L 1 +L 2 ), and a third value (L 1 +L 2 +L 3 ). The first value may be used when audio circuit  76  is active (mode  1 ), the second value may be used when HAC transmitter  44  is active (mode  2 ), and the third value may be used when NFC transmitter  42  is active (as an example). Different types of operation may be associated with modes  1 ,  2 , and  3  if desired. The example of  FIG. 8  is merely illustrative. 
       FIG. 9  is a table of illustrative inductance settings that may be used for near field communications element  22  in different modes of operation when using a device having circuitry of the type shown in  FIG. 7 . As shown in  FIG. 9 , the switching circuitry of near field communications element  22  may adjust the inductance of near field communications element  22  between a first value (L 1 ) and a second value (L 1 +L 2 ). The first value may be used when audio circuit  76  is active while transmitters  42  and  44  are inactive (mode A) and may be used when HAC transmitter  44  is active while transmitter  42  and audio circuit  76  are inactive (mode B). When it is desired to use NFC transmitter  42 , audio circuit  76  may be deactivated and HAC transmitter  44  may be deactivated while adjusting near field communications element  22  to exhibit an inductance value of L 1 +L 2  (mode C). Different types of operation may be associated with modes A, B, and C if desired. The example of  FIG. 9  is merely illustrative. 
     Inductive components for near field communications element  22  can be formed from components other than speakers. In general, the coils (inductive element) associated with any suitable transducer structures in device  10  may be used as part of near field communications element  22 . Examples of components that include inductors (coils) that may be used as all or part of near field communications element  22  include vibrators (e.g., vibrators that create vibrations within device  10  to signal the presence of an incoming telephone call), motors, solenoids, other electromagnetic actuators, etc. These various different types of transducer may have an associated inductance value L when used in implementing all or part of near field communications element  22  (e.g., an adjustable or fixed near field communications element). Switching circuitry  40  may selectively couple element  22  to a transducer driver  76  (e.g., an audio circuit when the transducer is a speaker, a vibrator driver circuit when the transducer is a vibrator, etc.) or one or more near field communications transmitters (e.g., an NFC transmitter for wireless payments, a HAC transmitter for hearing aid signals, etc.). 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20110830
Publication Date: 20150825
Grant Date: 20150825
Priority Date: 20110830
Inventors: KOLE JARED M.
WITTENBERG MICHAEL B.
COHEN SAWYER I.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B5/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/7253", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0081", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M2250/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/72591", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0031", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/72478", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M2250/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/72412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/72412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/72478", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M2250/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B5/72", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 47744392