PATENT DOCUMENT

Publication Number: US-10958310-B2
Application Number: US-201916251904-A
Country: US
Kind Code: B2

Title: Wirelessly charged electronic device with shared inductor circuitry

Abstract:
An electronic device may contain an input-output device such as a speaker, vibrator, or near field communications antenna. The input-output device may include an inductor. The inductor in the input-output device may be shared by wireless charging circuitry in the electronic device so that wireless charging signals can be converted into power to charge a battery in the electronic device. A separate inductor may also be provided within an input-output device to support wireless charging. A drive circuit may supply drive signals to the input-output device such as audio signals, vibrator control signals, or near field communications output signals for external near field communications equipment. An input amplifier that is coupled across the inductor in the input-output device may be used in receiving near field communications signals.

Claims:
What is claimed is: 
     
       1. A wristwatch device that is configured to be wirelessly charged using external equipment and to wirelessly communicate with an external device, the wristwatch device comprising:
 a battery; 
 wireless charging circuitry configured to charge the battery using wireless charging signals received from the external equipment; 
 wireless communications circuitry that is configured to receive wireless communications signals from the external device; 
 an inductor, wherein the wireless charging circuitry is configured to receive the wireless charging signals using the inductor and the wireless communications circuitry is configured to receive the wireless communications signals using the inductor; and 
 control circuitry that is configured to selectively switch the inductor between receiving the wireless charging signals and receiving the wireless communications signals. 
 
     
     
       2. The wristwatch device defined in  claim 1  wherein the wireless communications circuitry includes near field communications circuitry and the inductor is configured to receive near field communications signals from the external device. 
     
     
       3. The wristwatch device defined in  claim 2  further comprising:
 a switch between the wireless charging circuitry and the wireless communications circuitry, wherein the control circuitry is configured to send control signals to the switch based on whether the inductor has received the wireless charging signals or the wireless communications signals. 
 
     
     
       4. The wristwatch device defined in  claim 1  further comprising:
 a housing, wherein the battery, the wireless charging circuitry, the wireless communications circuitry, and the inductor are mounted in the housing; and 
 a touch screen display in the housing that is powered by the battery. 
 
     
     
       5. The wristwatch device defined in  claim 4  wherein the touch screen display includes at least one force-based component. 
     
     
       6. The wristwatch device defined in  claim 4  further comprising a button in the housing that is separate from the touch screen display. 
     
     
       7. The wristwatch device defined in  claim 4  further comprising:
 circuitry in the housing that is driven to produce a physical vibration that serves as an alert. 
 
     
     
       8. The wristwatch device defined in  claim 4  wherein the housing has first and second sides, wherein the first side is configured to be coupled to a first end of a wrist strap and the second side is configured to be coupled to a second end of the wrist strap. 
     
     
       9. The wristwatch device defined in  claim 4  further comprising an audio device mounted in the housing, the audio device selected from the group of devices consisting of: a speaker and a microphone. 
     
     
       10. A wristwatch device configured to be coupled to a strap, the wristwatch device comprising:
 a housing having first and second sides, wherein the first side is configured to be coupled to a first end of the strap and the second side is configured to be coupled to a second end of the strap; 
 a touch screen display in the housing, wherein the touch screen display comprises at least one force-based component; 
 wireless communications circuitry in the housing; 
 a fixedly attached battery in the housing that powers the touch screen display, the circuitry, and the wireless communications circuitry; 
 a button in the housing, wherein the button is separate from the touch screen display; and 
 wireless charging circuitry in the housing that charges the battery using received wireless charging signals. 
 
     
     
       11. The wristwatch device defined in  claim 10  further comprising:
 circuitry in the housing that is driven to produce a physical vibration that serves as an alert for an event. 
 
     
     
       12. The wristwatch device defined in  claim 10  wherein the wireless communications circuitry is configured to wirelessly communicate with a portable wireless electronic device. 
     
     
       13. The wristwatch device defined in  claim 10  wherein the wireless communications circuitry includes near field communications circuitry in the housing that is configured to receive near field communications signals from external equipment. 
     
     
       14. The wristwatch device defined in  claim 10 , further comprising:
 an inductor, wherein the wireless communications circuitry is configured to receive wireless communications signals using the inductor and the wireless charging circuitry is configured to receive the wireless charging signals using the inductor. 
 
     
     
       15. A wristwatch device configured to be coupled to a strap and to communicate with external equipment, the wristwatch device comprising:
 a housing having first and second sides, wherein the first side is configured to be coupled to a first end of the strap and the second side is configured to be coupled to a second end of the strap; 
 near field communications circuitry within the housing, wherein the near field communications circuitry is configured to send near field communications signals to the external equipment; 
 a touch screen display in the housing; 
 a button in the housing that is separate from the touch screen display; 
 a battery fixedly attached to the housing; and 
 wireless charging circuitry in the housing configured to charge the battery using charging signals received from additional external equipment. 
 
     
     
       16. The wristwatch device defined in  claim 15  further comprising circuitry within the housing that is configured to generate a physical vibration alert. 
     
     
       17. The wristwatch device defined in  claim 15  wherein the near field communications circuitry is configured to make wireless payments with point of sale equipment using the near field communications signals. 
     
     
       18. The wristwatch device defined in  claim 17  further comprising:
 an inductor, wherein the near field communications circuitry is configured to receive the near field communications signals using the inductor and the wireless charging circuitry is configured to receive the wireless charging signals using the inductor.

Description:
This application is a continuation of U.S. patent application Ser. No. 15/054,616, filed Feb. 26, 2016, which is a continuation of U.S. patent application Ser. No. 13/776,436, filed Feb. 25, 2013, now U.S. Pat. No. 9,276,639, which are hereby incorporated by reference herein their entireties. This application claims the benefit of and claims priority to U.S. patent application Ser. No. 15/054,616, filed Feb. 26, 2016, and U.S. patent application Ser. No. 13/776,436, filed Feb. 25, 2013, now U.S. Pat. No. 9,276,639. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless charging circuitry. 
     Electronic devices often include batteries. A battery in an electronic device can often be charged by using a cable to couple the electronic device to a source of power. It is not always convenient to rely on wired charging arrangements such as these. In compact and portable devices, for example, the use of a charging cable may be unwieldy. Charging cables can be avoided by using wireless charging, but wireless charging circuitry can be bulky. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless charging capabilities. 
     SUMMARY 
     An electronic device may contain an input-output device such as a speaker, vibrator, or near field communications antenna. The input-output device may include an inductor. For example, a speaker may include an inductor called a voice coil that is coupled to a speaker diaphragm. The speaker may contain travel-limiting stop structures. When the speaker is overdriven using vibrator control signals, the voice coil will strike the travel-limiting stop structures. In this mode of operation, the speaker may be operated as a vibrator. In configurations in which the inductor serves as a near field communications antenna, the inductor may be used in transmitting and receiving near field communications signals. 
     The inductor in the input-output device may be shared by wireless charging circuitry in the electronic device so that wireless charging signals can be converted into power to charge a battery in the electronic device. The wireless charging circuitry may include a capacitor to help convert alternating current wireless charging signals into direct current signals for charging the battery and powering circuitry in the electronic device. Switching circuitry in the wireless charging circuitry can selectively couple the capacitor to the inductor when wireless charging signals are being received and converted into power in the electronic device and can selectively isolate the inductor from the capacitor when it is desired to use the inductor as part of a speaker, vibrator, or near field communications circuit. 
     If desired, a separate inductor that is co-located with the input-output device inductor may be provided to support wireless charging. With this type of configuration, the drive circuit may supply drive signals to the inductor of the input-output device such as audio signals, vibrator control signals, or near field communications output signals for a hearing aid or other external near field communications equipment. An input amplifier that is coupled across the inductor in the input-output device may be used in receiving near field communications signals. When it is desired to receive wireless charging signals, the wireless charging signals may be received using the separate inductor. 
     Further features, their 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 wireless charging capabilities in accordance with an embodiment. 
         FIG. 2  is a schematic view of an illustrative electronic device of the type that may be provided with wireless charging capabilities and associated external equipment in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an audio transducer such as a speaker in accordance with an embodiment. 
         FIG. 4  is a circuit diagram of an electronic device having an input-output device such as an electroacoustic transducer, near field communications antenna, or other electronic component with an inductor of the type that may be used in supporting wireless charging in accordance with an embodiment. 
         FIGS. 5 and 6  are graphs showing illustrative drive signals that may be applied to an electronic component such as an electroacoustic transducer in an electronic device with wireless charging capabilities in accordance with an embodiment. 
         FIG. 7  is a graph in which characteristics of an electroacoustic transducer have been plotted as a function of operating frequency in an electronic device in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an audio transducer such as a speaker that has been provided with an ancillary co-located inductor coil to handle wireless charging functions in accordance with an embodiment. 
         FIG. 9  is a circuit diagram of an electronic device having an input-output device such as an electroacoustic transducer and an ancillary inductor coil for handling wireless charging functions in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device that may be provided with wireless charging capabilities is shown in  FIG. 1 . Electronic devices such as device  10  of  FIG. 1  may be cellular telephones, media players, other handheld portable devices, somewhat smaller portable devices such as wrist-watch devices, pendant devices, or other wearable or miniature devices, gaming equipment, tablet computers, notebook computers, desktop computers, televisions, computer monitors, computers integrated into computer displays, or other electronic equipment. As an example, device  10  may be a small portable device such as a wristwatch device that is attached to the wrist of a user with optional strap  16 . Configurations for device  10  in which device  10  is a wristwatch device or other compact portable device benefit from the inclusion of compact wireless charging circuitry but wireless charging circuitry may be provided in other types of electronic device if desired. 
     In the configuration of  FIG. 1 , device  10  includes a display such as display  14 . Display  14  has been mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer and in housing  12  to accommodate buttons, speaker ports, data ports, audio jack connectors, and other components. 
     A schematic diagram of device  10  and associated external equipment is shown in  FIG. 2 . In system  18  of FIG.  2 , device  10  may receive wireless power from wireless charging equipment  34  in the form of wireless radio-frequency signals  40 . Tuned circuitry within device  10  may receive radio-frequency signals  40  and may convert the alternating current (AC) power associated with the received radio-frequency signals into direct current (DC) power for powering electronic device  10 . 
     Device  10  may use wireless paths such as a wireless path associated with wireless signals  48  and wired paths such as optional path  50  to communicate with external equipment  42 . External equipment  42  may include one or more devices such computers or other computing equipment. For example, external equipment  42  may include one or more cellular telephones, media players, other handheld portable devices, somewhat smaller portable devices such as wrist-watch devices, pendant devices, or other wearable or miniature devices, gaming equipment, tablet computers, notebook computers, desktop computers, televisions, computer monitors, computers integrated into computer displays, 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.), other near field communications equipment, or other external equipment. 
     Wireless communications paths such as the wireless communications path associated with wireless signals  48  may support wireless communications such as near field communications, cellular telephone communications, wireless local area network communications, etc. As an example, device  10  may sometimes use wireless signals  48  and near field communications to 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 using near field communications, may place device  10  near a door lock when it is desired to obtain access to a building using near field communications, may place device  10  near a security card reader when it is desired to authenticate to a computer system using near field communications, and may place device  10  near to a hearing aid when it is desired to communicate with the hearing aid using near field communications. A near field communications antenna in device  10  may be used to support near field communications. Device  10  may use antennas and radio-frequency transceiver circuitry to communicate with cellular telephone towers and other cellular telephone network equipment, wireless local area network wireless equipment, peer devices, computing equipment, and other external equipment  42 . 
     External equipment  42  may include control circuitry  46  and communications circuitry  44 . Control circuitry  46  may include one or more integrated circuits such as processors, memory circuits, and application-specific integrated circuits. Communications circuitry  44  may include circuitry for supporting wired and wireless communications. For example, communications circuitry  44  may include serial and parallel digital communications circuits for handling communications over wired path  50 . Communications circuitry  44  may also include antenna structures and radio-frequency transceiver circuitry for handling wireless communications with device  10  (e.g., for transmitting and receiving wireless signals  48 ). 
     Wireless charging equipment  34  may receive power from sources such as AC input  41 . Power supply circuitry such as converter  39  may be used to convert AC input power on input  41  to DC power for powering the circuitry of wireless charging equipment  34 . During operation, wireless charging equipment  34  may use radio-frequency circuitry such as radio-frequency transmitter  36  to generate radio-frequency signals  40  that are wirelessly transmitted to device  10  using inductor circuitry such as inductor  38 . Device  10  can receive the transmitted radio-frequency signals  40  using inductor circuitry based on one or more inductors  52  and can convert these received signals into power for device  10 . For example, system  18  may use resonant inductive coupling (near field electromagnetic coupling) between inductor  38  and a corresponding inductor  52  in device  10  to transfer power from wireless charging equipment  34  and device  10 . An illustrative frequency for transmitted RF energy using signals  40  is 200 kHz. Other frequencies may be used, if desired (e.g., frequencies in the kHz range, the MHz range, or in the GHz range, frequencies of 1 kHz to 1 MHz, frequencies of 1 kHz to 100 MHz, etc.). 
     Electronic device  10  may include control circuitry such as storage and processing circuitry  20 . Control circuitry  20  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. 
     Input-output circuitry  22  may be used in supplying output to users of device  10  and external equipment and may be used in receiving input from users and external equipment. Input-output circuitry  22  may include communications circuitry  24  and input-output devices  32 . 
     Device  10  may use communications circuitry  24  for communicating with communications circuitry  44  of external equipment  42  over wired path  50  and using wireless signals  48  over a corresponding wireless path. Communications circuitry  24  and  44  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 wired and wireless communications. With one illustrative arrangement, device  10  includes a transmitter (i.e., communications circuitry  24  may include a transmitter) and equipment  42  includes a corresponding receiver (i.e., communications circuitry  44  includes a receiver). This type of arrangement may be used to support unidirectional wireless communications between device  10  and external equipment  42 . 
     If desired, bidirectional wireless communications may be supported. For example, communications circuitry  44  may include a transmitter and a receiver and communications circuitry  24  may include a corresponding transmitter and a receiver. 
     Antenna structures may be provided in electronic device  10  and external equipment  42  for supporting near field communications and other wireless communications. The antenna structures may include near field coupled inductors. Wireless communications signals  48  that are transmitted using a wireless path may, in general, be communicated from device  10  to equipment  42 , from equipment  42  to device  10 , or both from device  10  to equipment  42  and from equipment  42  to device  10 . Wireless signals  40  may be used to transmit power from wireless charging equipment  34  to device  10  and may, if desired, be used in transferring unidirectional or bidirectional data between device  10  and equipment  34 . 
     Input-output circuitry  22  may include input-output devices  32  such as buttons, joysticks, click wheels, scrolling wheels, a touch screen such as display  14  of  FIG. 1 , other touch sensors such as track pads or touch-sensor-based buttons, vibrators such as vibrator  28 , audio components such as microphones and speakers such as speaker  26 , image capture devices such as a camera module having an image sensor and a corresponding lens system, keyboards, status-indicator lights, tone generators, key pads, and other equipment for gathering input from a user or other external source and/or generating output for a user. 
     As shown in  FIG. 2 , components such as audio transducers (e.g., illustrative speaker  26  and vibrator  28  of  FIG. 2 ) may include inductor circuitry such as one or more inductors  52 . For example, speaker  26 , which may serve as an audio speaker or both as an audio speaker and as a vibrator, may have an inductor of the type that is sometimes referred to as a voice coil. The inductor is driven with signals that cause a diaphragm to move, thereby producing sound. As another example, vibrator  28  may have a weight (e.g., a rotationally asymmetric weight) that is driven by a motor with a rotating shaft. The motor may have one or more inductors such as inductor  54  of vibrator  28  of  FIG. 2 . 
     If desired, additional circuitry in device  10  such as other devices  30  may have one or more inductors. Examples of other devices that may include inductor circuitry include communications circuits such as near field communications antennas and other wireless communications components for communicating with external equipment  42  such as a hearing aid or other near field communications equipment. Near field communications may involve inductively coupled near field communications in which both the transmitter and receiver have associated inductors that are electromagnetically coupled (as shown schematically by wireless signals  48  of  FIG. 2 ). 
     Inductors  52  consume space within electronic device  10 . To minimize the amount of space consumed by the inductor circuitry used for supporting wireless charging with wireless charging equipment  34  and the inductor circuitry used in input-output devices  32 , device  10  can use shared and/or co-located inductor configurations. For example, device  10  may have an inductor that is shared between an input-output device such as a speaker (or other input-output device) and a wireless charging circuit. By using the inductor for dual purposes (both as part of a tuned inductor circuit that receives wireless power and as part of an audio transducer in this example), duplication of resources and the size of device  10  can be minimized. 
       FIG. 3  is a cross-sectional view of an illustrative input-output device  32  such as a speaker. As shown in  FIG. 3 , device (speaker)  26  includes inductor  52 . Inductor  52  may be used in operating speaker  26  to produce sound and may be used in receiving wireless power from wireless charging equipment  34 . In the  FIG. 3  example, the input-output device that is illustrated is a speaker. In general, however, inductor  52  may be incorporated into vibrator  28  or other input-output devices  30  such as near field communications antennas and other components, etc. Configurations in which inductor  52  is incorporated into speaker  26  may sometimes be described herein as an example. 
     Inductor  52 , which may sometimes be referred to as a speaker voice coil, speaker coil, or voice coil, may contain one or more turns of wire  58 . Speaker  26  may use a moving coil design or a moving magnet design. In the illustrative configuration of  FIG. 3 , speaker  26  has a moving coil design in which inductor  52  moves in upwards direction  60  and downwards direction  62  relative to stationary magnet  66 . Diaphragm  68  is connected to inductor  52 , so movement of inductor  52  causes corresponding movement in diaphragm  68 . Inductor  52  may have a circular outline (when viewed in direction Z) and speaker  26  may have a corresponding circular shape. Support structures  72  may surround the periphery of speaker  26  of speaker. Surround  70  couples inductor (coil)  52  to support structures  72 . Diaphragm  68  may have a circular shape that fills the center of inductor (coil)  52 . 
     Internal speaker support structures  76  may serve as travel-limiting stop structures for inductor  52  and speaker  26 . When driven with drive signals of sufficiently low magnitude, coil  52  will not contact surfaces  74  of travel-limiting stop structures  76 . In this type of low-magnitude speaker mode of operation, speaker  26  can produce audio output in response to the drive signal. When driven with drive signals of sufficiently large magnitude (sometimes referred to as overdrive signals in an overdriven mode of operation), coil  52  will contact surfaces  74  when driven downwards in direction  62 . The contact between coil  52  and surfaces  74  of travel-limiting stop structures  76  will limit the maximum downwards travel of speaker coil  52 . In overdriven mode of operation, speaker  26  can operate as a vibrator that creates a buzzing sound and a noticeable physical vibration that can be felt by a user holding device  10 . During operation of device  10 , speaker  26  may be supplied with a low magnitude audio drive signal so that speaker  26  can be used to produce audio output in connection with playing media or supplying sound for a voice telephone call or speaker  26  may be supplied with an overdriven vibrator control signal so that speaker  26  can serve as a vibrator to alert a user to incoming telephone calls, alarm events, and other events for which a more silent mode of providing output for the user is desired. 
     To support wireless charging operations, coil  52  can serve as the inductor in an inductively coupled wireless power transfer circuit.  FIG. 4  is a circuit diagram of illustrative circuitry for device  10  showing how inductor  52  may be used both as a portion of an input-output device such as a speaker, vibrator, or near-field communications antenna and as a portion of wireless charging circuit for charging battery  110  from wireless signals  40 . 
     As shown in  FIG. 4 , inductor  52  may be coupled between terminals  78  and  80 . Terminals  78  and  80  may be coupled to wireless charging circuitry  114  such as power management circuitry  102  and capacitor  104 . Power management circuitry  102  may be used in converting alternating current power received by inductor  52  from inductor  38  of wireless charging equipment  34  in the form of wireless signals  40  to DC power. Capacitor  104  may be used as a charge storage element that helps in converting received radio-frequency (alternating current) signals  40  to direct current (DC) power. Power management circuitry  102  may also be used in routing DC power from capacitor  104  to battery  110  to charge battery  110  may be used in routing DC power to power supply terminals  112 . The power supply voltage (e.g., voltage Vdc in the  FIG. 4  example) that is produced across terminals  112  may be used in powering control circuitry  20  and input-output circuitry  22  of device  10 . When wireless power is not available from wireless power signals  40 , power may be supplied to control circuitry  20  and input-output circuitry  22  from battery  110 . 
     Switch  106  may be controlled by control circuitry  20  using input on control line  108 . When it is desired to use the circuitry of  FIG. 4  in wireless charging mode, switch  106  may be placed in a closed state to couple capacitor  104  across terminals  78  and  80  of inductor  52  and connecting inductor  52  to wireless charging circuit  114 . When it is desired to drive signals through inductor  52  (i.e., when using the input-output device  32  in which inductor  52  is contained), a control signal may be supplied to control line  108  that places switch  106  in an open state, thereby decoupling capacitor  104  and wireless charging circuit  114  from inductor  54 . 
     Inductor  52  may be a voice coil, part of a motor in a vibrator, a near field communications antenna, or other structure in input-output device  32 . Input-output device  32  may be a speaker, vibrator, a near-field communications inductor circuit such as a near field communications antenna circuit coupled to near field communications circuitry  24  for transmitting near field communications signals  48  to a hearing aid or other external equipment  42 , or other component in device  10  that contains inductor  52 . 
     Drive signals for the speaker, vibrator, or near-field communications circuit may be supplied using an output driver (sometimes referred to as an output amplifier, output buffer, or output circuit) such as output driver  82  of  FIG. 4 . As shown in  FIG. 4 , driver  82  may have input  100  for receiving input signals. Driver  82  may use input  100  as an input path to receive input from circuitry in device  10  such as communications circuitry  24  and/or control circuitry  20 . The input signals that re received on input  100  may be audio input signals, vibrator control signals, data that is being transmitted to a hearing aid or other external equipment via near field communications, etc. Based on the input received at input  100 , driver  82  may produce output drive signals across terminals  78  and  80  using signal lines  84  and  86 , respectively. 
     The type of signals that are provided on output lines  84  and  86  depends on the nature of device  32 . In configurations in which device  32  is a speaker, the signals that are provided to lines  84  and  86  and that are driven through inductor  52  will be audio signals (i.e., inductor  52  will operate as a speaker voice coil). In configurations in which device  32  is a speaker that operates both as a speaker and (when overdriven) as a vibrator, the signals on lines  84  and  86  will be audio signals for operating device  32  in speaker mode or vibrator control signals for operating device  32  in vibrator mode. In configurations in which device  32  is a near field communications component (e.g., a near-field communications antenna formed by inductor  52 ), the signals on lines  84  and  86  will be hearing aid signals or other near field communications signals (see, e.g., wireless signals  48  of  FIG. 2 ). 
     The circuitry of  FIG. 4  therefore allows inductor  52  to be shared between multiple functions. When it is desired to receive wireless power in device  10  from wireless charging equipment  34 , switch  106  is closed and inductor  52  serves as a near field coupled inductive antenna that is coupled to inductor  38  through near field electromagnetic coupling, allowing wireless power to be transferred from wireless charging equipment  34  to device  10  via wireless signals  40 . Power management circuitry  102  may be used to deliver this received wireless power to the load across terminals  112  (i.e., the circuitry of device  10 ) and/or battery  110 . When it is desired to use inductor  52  as part of input-output device  32  (e.g., as a speaker, vibrator, or near field communications antenna for transmitting signals  48  to external equipment  42  of  FIG. 2 ), switch  106  is opened and signals are provided to inductor  52  from driver  82 . 
     If desired, signals such as near field communications signals from a hearing aid or other external equipment  42  may be received by inductor  52  (e.g., when inductor  52  is being used to form a near field communications antenna that receives data in the form of wireless signals  48 ). In this type of scenario, paths  84  and  86  may supply the received signals from inductor  52  to terminals  90  and  88 , respectively. Respective input lines  94  and  92  of input amplifier  96  may drive the received signals onto path  98 . Path  98  may be used to provide data corresponding to the received signals  48  to circuitry in device  10  such as communications circuitry  24  and control circuitry  20 . During the process of receiving near field communications data via inductor  52 , switch  106  may be opened to isolate inductor  52  from capacitor  104  and wireless charging circuitry  114 . 
       FIG. 5  is a graph showing illustrative control signals that may be provided to a speaker such as speaker  26  when operated in a vibrator mode. In particular, trace  116  of  FIG. 5  corresponds to signals that may be driven by driver  82  across a voice coil in speaker  26  such as inductor  52  of  FIG. 4 . As shown in  FIG. 5 , trace  116  may be a square wave with a fixed amplitude (AMP) and a period of T 1 . The period T 1  may be selected so that trace  116  exhibits a frequency of about 20-500 Hz (as an example). The peak magnitude of trace  116  may be selected so as to overdrive a voice coil in speaker  26  (i.e., so that inductor  52  strikes travel-limiting structures  76  of  FIG. 3 ). Drive signals such as the drive signal of  FIG. 5  may also be used in operating vibrators with inductor circuitry such as inductor  52  (i.e., vibrator devices such as motors with asymmetric weights that do not serve dual functions as both vibrators and speakers). 
       FIG. 6  shows how a vibrator control signal for a vibrator or for a speaker operating in a vibrator mode may take the form of a square wave  116 ′ of period T 1 . Drive signal  116 ′ has an amplitude that is bounded by envelope  118 . Envelope  118  may have a frequency that is lower than the frequency of drive signal  116 ′. Envelope  118  may have a square wave shape, a sinusoidal shape (as in the example of  FIG. 6 ), a triangular shape, or other shape. The period T 2  of envelope  118  may be in the range of 0.1 s to 1 s (as an example). When device  10  applies the drive signal of  FIG. 6  to inductor  52 , the speaker or vibrator in device  10  may exhibit a periodic buzzing behavior to alert a user of the occurrence of an incoming message, telephone call, or other event. 
     In configurations in which it is desired to operate speaker  26  in a vibrator mode, speaker  26  may exhibit a resonance at a resonant frequency (f 1 ), as illustrated in the upper trace of  FIG. 7  in which speaker amplitude has been plotted as a function of operating frequency f. The presence of the resonance at frequency f 1  may allow speaker  26  to be overdriven using vibrator control signals of the type shown in  FIGS. 5 and 6  so that the speaker functions as a vibrator. Due to the presence of the f 1  resonance, speaker  26  may exhibit an impedance R of the type plotted in the middle trace of  FIG. 7  (i.e., speaker  26  may exhibit a dip in impedance at resonance frequency f 1 ). When speaker  26  is operated in speaker mode, it may be desirable to equalize the audio signals that are being used to drive inductor (voice coil)  52  in speaker  26  by incorporating an equalization curve such as curve AUDIO_EQ into the output performance of driver  82  (e.g., by incorporating filter circuitry into driver  82 ). Use of this type of equalization curve, which exhibits a drop in transmission at frequency f 1 , compensates for the lowered impedance R of speaker  26  at frequency f 1 , thereby ensuring that audio playback is characterized by a flat frequency response. 
     If desired, the wireless charging inductor in device  10  may be separate from the inductor used in input-output device  32 . For example, a first inductor may be used for receiving wireless charging signals  40  and a second inductor may be used as part of input-output device  32  (e.g., as a voice coil in a speaker, as an inductive element in a vibrator, as a near field communications antenna for communicating wirelessly via signals  48  with external equipment  42 , etc.).  FIG. 8  is a cross-sectional side view of an illustrative input-output device  32  such as speaker  26  (or a vibrator, near field communications antenna or other device) showing how the first and second inductors may be co-located. In the  FIG. 8  example, speaker  26  has a first inductor such as voice coil inductor  52 A for driving diaphragm  68  to produce sound (or to operate speaker  26  in vibrator mode by overdriving coil  52 A until coil  52 A strikes travel-limiting surfaces  74  of travel-limiting stop structures  76 ) and has a second inductor such as inductor  52 B for serving as a wireless charging inductor that receives wireless signals  40  from inductor  38  in wireless charging equipment  34 . 
     Inductors  52 A and  52 B are both located within the same input-output device  32  (speaker  26  in the  FIG. 8  example), so inductors  52 A and  52 B may sometimes be referred to as being co-located inductors. Inductors  52 A and  52 B may be coils that are wound on a common support structure, may be concentric coils mounted on separate support structures, or may otherwise be integrated into a common input-output device  32  such as speaker  26 . There is generally space available within devices such as speaker  26  in which to mount inductors such as separate wireless charging inductor  52 B, so the use of a co-located mounting arrangement for mounting the first and second inductors can save space within device  10 . 
       FIG. 9  is a circuit diagram of device  10  in a configuration in which separate inductors  52 A and  52 B such as co-located inductors are being used in speaker  26  or other input-output device  32  of  FIG. 8  or other separate inductor structures. As shown in  FIG. 9 , inductor  52 B forms part of wireless charging circuitry  114 . Terminals  78 B and  80 B in wireless charging circuitry  114  may be coupled to circuitry such as power management circuitry  102  and capacitor  104 . During wireless power transfer operations, wireless charging circuitry such as power management circuitry  102  may be used in converting alternating current power received by inductor  52 B from inductor  38  of wireless charging equipment  34  in the form of wireless signals  40  to DC power. Capacitor  104  helps in converting received radio-frequency (alternating current) signals  40  to DC power. Power management circuitry  102  may route DC power from across capacitor  104  to battery  110  to charge battery  110  and/or power management circuitry  102  may route DC power to power supply terminals  112  to power the circuitry of device  10 . The power supply voltage Vdc of  FIG. 9  may, for example, be used in powering control circuitry  20  and input-output circuitry  22  of device  10 . When wireless power is not available from wireless power signals  40 , power may be supplied to control circuitry  20  and input-output circuitry  22  of device  10  from battery  110 . 
     Terminals  78 A and  80 A of inductor  52 A are not shorted across terminals  78 B and  80 B because inductor  52 A is separate from inductor  52 B in the configuration of  FIG. 9 . As a result, switch  106  of  FIG. 4  may, if desired, be omitted from circuitry  114  of  FIG. 9 . As shown in  FIG. 9 , inductor  52 A may form part of input-output device  32 . Input-output device  32  of  FIG. 9  may be a speaker, may be a vibrator, may be a near field communications inductor circuit such as a near field communications antenna for transmitting near field communications signals  48  to a hearing aid or other external equipment  42  and for receiving incoming near field communications signals  48 , or may be another component in device  10  that contains inductor  52 A. 
     Drive signals for the speaker, vibrator, or near-field communications circuit may be supplied across terminals  78 A and  80 A using an output driver such as output driver  82 . As shown in  FIG. 9 , driver  82  may have input  100  for receiving input signals. Input from circuitry in device  10  such as communications circuitry  24  and/or control circuitry  20  may be supplied to driver circuit  82  using input  100 . The input that is received on path  100  may be audio input, vibrator control signals, data that is being transmitted to a hearing aid or other external equipment via near field communications, or other signals. Based on the input received at input path  100 , driver  82  may produce drive signals across terminals  78 A and  80 A using signal lines  84  and  86 , respectively. 
     In configurations in which device  32  is a speaker, the signals that are provided to inductor  52 A using lines  84  and  86  will be audio signals (i.e., inductor  52 A will be a speaker voice coil such as a voice coil co-located with wireless charging inductor  52 B). In configurations in which device  32  is a speaker that operates both as a speaker and as a vibrator (depending on whether or not the speaker is driven using audio signals or is overdriven using vibrator control signals), the signals on lines  84  and  86  will be audio signals for operating device  32  in speaker mode or vibrator control signals for operating device  32  in vibrator mode. In configurations in which device  32  is a near field communications component (e.g., a near-field communications antenna formed from inductor  52 A), the signals on lines  84  and  86  will be hearing aid signals or other near field communications signals for wirelessly transmitting to external equipment  42 . 
     As with the shared inductor configuration of  FIG. 4 , the separate inductor configuration of  FIG. 9  allows device  10  to perform multiple functions. When it is desired to receive wireless power in device  10  from wireless charging equipment  34 , inductor  52 B in wireless charging circuit  114  can receive wireless power from wireless charging equipment  34  in the form of wireless signals  40 . Power management circuitry  102  may then be used to deliver this received wireless power to the load across terminals  112  and/or battery  110 . When it is desired to use input-output device  32  (e.g., as a speaker, vibrator, or near field communications antenna for transmitting signals  48  to external equipment  42  of  FIG. 2 ), signals can be provided to inductor  52 A from driver  82 . If desired, inductors  52 A and  52 B may be operated simultaneously. 
     Signals such as near field communications signals from a hearing aid or other external equipment  42  may be received by inductor  52 A when inductor  52 A is being used to form a near field communications antenna that receives data in the form of wireless signals  48 . In this configuration, the received signals from inductor  52 A are routed to the inputs of input amplifier  96 . Input-amplifier  96  may provide the received near field communications data received on its inputs to path  98 . Path  98  may then be used to provide data corresponding to the received signals  48  to circuitry in device  10  such as communications circuitry  24  and control circuitry  20 . Because inductor  52 A is separate from inductor  52 B in the arrangement of  FIG. 9 , it is not necessary to use an inductor isolation switch such as switch  106  of  FIG. 4  to isolate inductor  52 A from capacitor  104  during signal reception operations with input amplifier  96 . 
     Inductors such as inductors  52 ,  52 A,  52 B and other inductive circuitry in device  10  may be formed from one or more coils of wire, may be formed from structures that are formed within components of device  10  such as input-output devices  32  (e.g., within a speaker housing or other speaker structures, within a vibrator housing or other vibrator structures, within a near field communications antenna structure or other near field communications structures, etc.). 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20190118
Publication Date: 20210323
Grant Date: 20210323
Priority Date: 20130225
Inventors: TERLIZZI, JEFFREY J.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B5/266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00034", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W12/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W12/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R25/602", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W12/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F2038/143", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00034", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B1/385", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W12/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0006", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B5/0031", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R25/602", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0037", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W12/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/385", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W12/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F2038/143", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B5/79", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/79", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/72", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 51388189