PATENT DOCUMENT

Publication Number: US-9232306-B2
Application Number: US-201313833636-A
Country: US
Kind Code: B2

Title: Systems and methods for reducing stray magnetic flux

Abstract:
Systems and methods for reducing the effects of stray magnetic flux are provided. For example, an electronic device can employ the system and can include a first audio component configured to have a first acoustic phase and a first magnetic phase. The electronic device can also include a second audio component configured to have the first acoustic phase and a second magnetic phase that is opposite the first magnetic phase. The first audio component can be positioned with respect to the second audio component, such that any stray magnetic flux from the first audio component enters the second audio component during operation of the first and second audio components.

Claims:
What is claimed is:   
     
       1. A handheld electronic device comprising:
 one of a laptop computer, a tablet computer, or a cellular telephone that includes: 
 a first audio component configured to have a first acoustic phase and a first magnetic phase, 
 a second audio component configured to have the first acoustic phase and a second magnetic phase that is opposite the first magnetic phase, the first audio component being positioned with respect to the second audio component such that stray magnetic flux from the first audio component enters the second audio component during operation of the first and second audio components, wherein the first audio component is a first loudspeaker having a first electrically conductive coil and the second audio component is a second loudspeaker having a second electrically conductive coil that provide the first acoustic phase, and 
 a sensor of the handheld electronic device, the sensor responsive to stray magnetic flux of another component, the sensor disposed between the first audio component and the second audio component. 
 
     
     
       2. The electronic device of  claim 1 , wherein the first audio component is positioned adjacent the sensor, and the sensor is positioned adjacent the second audio component. 
     
     
       3. The electronic device of  claim 1 , wherein the sensor is:
 a hall effect sensor. 
 
     
     
       4. The electronic device of  claim 1 , wherein the first audio component comprises a first magnet being oriented to provide the first magnetic phase. 
     
     
       5. The electronic device of  claim 4 , wherein the first magnet is oriented to provide the first magnetic phase. 
     
     
       6. The electronic device of  claim 5 , wherein the second audio component comprises a second magnet being oriented to provide the second magnetic phase. 
     
     
       7. The electronic device of  claim 6 , wherein the second magnet is orient to provide the second magnetic phase. 
     
     
       8. The electronic device of  claim 1 , wherein the first audio component comprises a first coil former and the first electrically conductive coil, the first coil being wound around at least a portion of the first coil former. 
     
     
       9. The electronic device of  claim 1 , wherein the first audio component is positioned with respect to the second audio component such that the stray magnetic flux from the first audio component and stray magnetic flux from the second audio component form a single closed flux loop. 
     
     
       10. A method of manufacturing a handheld electronic device, the method comprising:
 positioning a first audio component within the electronic device; the electronic device including one of a laptop computer, a tablet computer, or a cellular telephone; the first audio component being positioned to provide a first acoustic phase and a first magnetic phase; 
 situating a second audio component within the electronic device, the second audio component being situated to provide the first acoustic phase and a second magnetic phase opposite the first magnetic phase, and the first and second audio components being oriented relative to one another, such that the first and second magnetic phases cause stray magnetic flux from the first audio component to enter the second audio component during operation of the first and second audio components, wherein the first audio component is a first loudspeaker having a first electrically conductive coil and the second audio component is a second loudspeaker having a second electrically conductive coil to provide the first acoustic phase; and 
 situating a sensor within the handheld electronic device, the sensor responsive to stray magnetic flux of another component, the sensor disposed between the first audio component and the second audio component. 
 
     
     
       11. The method of  claim 10 , wherein the positioning comprises orienting the first audio component such that a first magnet of the first audio component is in a first orientation. 
     
     
       12. The method of  claim 10 , wherein the situating the second audio component comprises orienting the second audio component such that a second magnet of the second audio component is in a second orientation opposite the first orientation. 
     
     
       13. The method of  claim 10 , wherein the first and second audio components are oriented relative to one another such that stray magnetic flux from the first audio component and stray magnetic flux from the second audio component form a single closed flux loop. 
     
     
       14. The method of  claim 10 , wherein the first and second audio components are oriented relative to one another such that the first and second magnetic phases cause stray magnetic flux from the second audio component to enter the first audio component during operation of the first and second audio components. 
     
     
       15. The electronic device of  claim 1 , wherein an audio source of the electronic device is connected to apply a first audio signal to the first electrically conductive coil and a second audio signal to the second electrically conductive coil to provide the first acoustic phase, and the second audio signal is an electrically inverted version of the first audio signal. 
     
     
       16. The electronic device of  claim 15 , wherein the second audio signal is electrically inverted by one of (1) electrically inverting second electrical contacts of the audio source as compared to first electrical contacts of the audio source, or (2) using one of an inverter, an amplifier, a digital signal processing chain, or the audio source of the electronic device to electrically invert the second audio signal as compared to the first audio signal. 
     
     
       17. The method of  claim 10 , further comprising:
 connecting an audio source of the electronic device to apply a first audio signal to the first electrically conductive coil to provide the first acoustic phase, and to apply a second audio signal to the second electrically conductive coil to provide the first acoustic phase, wherein the second audio signal is an electrically inverted version of the first audio signal. 
 
     
     
       18. The method of  claim 17 , wherein the second audio signal is electrically inverted by one of (1) electrically inverting second electrical contacts of the audio source as compared to first electrical contacts of the audio source, or (2) using one of an inverter, an amplifier, a digital signal processing chain, or the audio source of the electronic device to electrically invert the second audio signal as compared to the first audio signal. 
     
     
       19. The electronic device of  claim 1 , wherein the sensor comprises one of a sensor that has its own magnetic flux, a sensor that is a magnetically sensitive input device component, or a sensor that may be affected by stray magnetic flux of another component. 
     
     
       20. The method of  claim 10 , wherein the sensor comprises one of a sensor that has its own magnetic flux, or a sensor that is a magnetically sensitive input device component.

Description:
FIELD OF THE INVENTION 
     This relates to systems and methods for reducing stray magnetic flux, and, more particularly, to systems and methods for reducing the effects of stray magnetic flux from a loudspeaker in an electronic device. 
     BACKGROUND OF THE INVENTION 
     As electronic devices and, more particularly, portable electronic devices (e.g., laptop computers, tablets, and cellular telephones) continue to get smaller, components of the devices continue to be positioned closer to one another. Certain device components, such as electrodynamic transducers (e.g., loudspeakers) often produce stray magnetic flux that is potentially disruptive to adjacent magnetically sensitive device components (e.g., Hall sensors and hard drives). If stray flux is not adequately kept away from certain magnetically sensitive components, those components may fail and/or cause damage to the electronic device. A traditional way to reduce such stray magnetic flux interference is to provide a shield about the component generating the stray magnetic flux and/or about the component to be protected from the stray magnetic flux. However, such a shield often takes up valuable real estate within a device. 
     SUMMARY OF THE INVENTION 
     Systems and methods for reducing stray magnetic flux in an electronic device are provided. 
     In at least one embodiment, an electronic device is provided. The electronic device can include a first audio component configured to have a first acoustic phase and a first magnetic phase, and a second audio component configured to have the first acoustic phase and a second magnetic phase that is opposite the first magnetic phase. The first audio component can be positioned with respect to the second audio component such that stray magnetic flux from the first audio component enters the second audio component during operation of the first and second audio components. For example, the stray magnetic flux can be encouraged to enter the second audio component and complete its flux loop. 
     In at least one embodiment, a method of manufacturing an electronic device is provided. The method can include positioning a first audio component within the electronic device. The first audio component can be positioned to provide a first acoustic phase and a first magnetic phase. The method can also include situating a second audio component within the electronic device. The second audio component can be situated to provide the first acoustic phase and a second magnetic phase opposite the first magnetic phase. The first and second audio components can also be oriented relative to one another such that the first and second magnetic phases cause stray magnetic flux from the first audio component to enter the second audio component during operation of the first and second audio components. For example, the stray magnetic flux can be encouraged to enter the second audio component and complete its flux loop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects of the invention, its nature, and various features will become more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1  is a simplified schematic diagram of an electronic device, in accordance with at least one embodiment of the invention; 
         FIG. 2  shows a top, front, right perspective view of the electronic device of  FIG. 1  in an open position, in accordance with at least one embodiment of the invention; 
         FIG. 3  shows a bottom, back, left perspective view of the electronic device of  FIGS. 1 and 2  in a closed position, in accordance with at least one embodiment of the invention; 
         FIG. 4  shows a partial cross-sectional view of a loudspeaker assembly, in accordance with at least one embodiment of the invention; 
         FIG. 5  shows a cross-sectional of a pair of adjacent magnet assemblies of corresponding loudspeakers, in accordance with at least one embodiment of the invention; and 
         FIG. 6  shows a cross-sectional view of a different pair of magnet assemblies of corresponding loudspeakers, in accordance with at least one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Systems and methods for reducing stray magnetic flux in an electronic device are provided and described with reference to  FIGS. 1-6 . 
       FIG. 1  is a simplified schematic diagram of an electronic device  100  that may be configured to reduce stray magnetic flux or leakage flux. Electronic device  100  may be any portable, mobile, or hand-held electronic device. Alternatively, electronic device  100  may not be portable, but may instead be generally stationary. Electronic device  100  can include, but is not limited to, a music player (e.g., an iPod™ available by Apple Inc. of Cupertino, Calif.), video player, still image player, game player, other media player, music recorder, movie or video camera or recorder, still camera, other media recorder, radio, medical equipment, domestic appliance, transportation vehicle instrument, musical instrument, calculator, cellular telephone (e.g., an iPhone™ available by Apple Inc.), other wireless communication device, personal digital assistant, remote control, pager, desktop computer (e.g., an iMac™ available by Apple Inc. of Cupertino, Calif.), laptop computer (e.g., a MacBook™ available by Apple Inc. of Cupertino, Calif.), tablet (e.g., an iPad™ available by Apple Inc. of Cupertino, Calif.), server, monitor, television, stereo equipment, set up box, set-top box, boom box, modem, router, printer, and combinations thereof. 
     Electronic device  100  may include a processor or control circuitry  102 , memory  104 , communications circuitry  106 , power supply  108 , input component  110 , and output component  112 . Electronic device  100  may also include a bus  114  that may provide one or more wired or wireless communication links or paths for transferring data and/or power to, from, or between various other components of device  100 . In some embodiments, one or more components of electronic device  100  may be combined or omitted. Moreover, electronic device  100  may include other components not combined or included in  FIG. 1 . For example, electronic device  100  may also include a compass, positioning circuitry, and/or several instances of one or more of the components shown in  FIG. 1 . For the sake of simplicity, only one of each of the components is shown in  FIG. 1 . 
     Memory  104  may include one or more storage mediums, including for example, a hard disk drive (“HDD”), flash memory, permanent memory such as read-only memory (“ROM”), semi-permanent memory such as random access memory (“RAM”), any other suitable type of storage component, or any combination thereof. Memory  104  may include cache memory, which may be one or more different types of memory used for temporarily storing data for electronic device applications. Memory  104  may store media data (e.g., music and image files), software (e.g., for implementing functions on device  100 ), firmware, preference information (e.g., media playback preferences), lifestyle information (e.g., food preferences), exercise information (e.g., information obtained by exercise monitoring equipment), transaction information (e.g., information such as credit card information), wireless connection information (e.g., information that may enable device  100  to establish a wireless connection), subscription information (e.g., information that keeps track of podcasts or television shows or other media a user subscribes to), contact information (e.g., telephone numbers and e-mail addresses), calendar information, any other suitable data, or any combination thereof. 
     Communications circuitry  106  may be provided to allow device  100  to communicate with one or more other electronic devices or servers using any suitable communications protocol. For example, communications circuitry  106  may support Wi-Fi (e.g., an 802.11 protocol), Ethernet, Bluetooth™, high frequency systems (e.g., 900 MHz, 2.4 GHz, and 5.6 GHz communication systems), infrared, transmission control protocol/internet protocol (“TCP/IP”) (e.g., any of the protocols used in each of the TCP/IP layers), hypertext transfer protocol (“HTTP”), BitTorrent™, file transfer protocol (“FTP”), real-time transport protocol (“RTP”), real-time streaming protocol (“RTSP”), secure shell protocol (“SSH”), any other communications protocol, or any combination thereof. Communications circuitry  106  may also include circuitry that can enable device  100  to be electrically coupled to another device (e.g., a host computer or an accessory device) and communicate with that other device, either wirelessly or via a wired connection. 
     Power supply  108  may provide power to one or more of the components of device  100 . In some embodiments, power supply  108  can be coupled to a power grid (e.g., when device  100  is not a portable device, such as a desktop computer). In some embodiments, power supply  108  can include one or more batteries for providing power (e.g., when device  100  is a portable device, such as a cellular telephone). As another example, power supply  108  can be configured to generate power from a natural source (e.g., solar power using solar cells). 
     One or more input components  110  may be provided to permit a user to interact or interface with device  100 . For example, input component  110  can take a variety of forms, including, but not limited to, a touch pad, dial, click wheel, scroll wheel, touch screen, one or more buttons (e.g., a keyboard), mouse, joy stick, track ball, microphone, camera, proximity sensor, Hall effect sensor, light detector, motion sensor, and any combinations thereof. Each input component  110  can be configured to provide one or more dedicated control functions for making selections or issuing commands associated with operating device  100 . 
     Electronic device  100  may also include one or more output components  112  that may present information (e.g., graphical, audible, and/or tactile information) to a user of device  100 . For example, output component  112  can take a variety of forms, including, but not limited to, audio loudspeakers, headphones, signal lines-out, visual displays, antennas, infrared ports, rumblers, vibrators, and any combinations thereof. 
     It should be noted that one or more input components  110  and one or more output components  112  may sometimes be referred to collectively herein as an input/output (“I/O”) component or I/O interface. For example, input component  110  and output component  112  may sometimes be a single I/O component, such as a touch screen, that may receive input information through a user&#39;s touch of a display screen and that may also provide visual information to a user via that same display screen. 
     Processor  102  of device  100  may include any processing circuitry operative to control the operations and performance of one or more components of electronic device  100 . For example, processor  102  may be used to run operating system applications, firmware applications, graphics editing applications, media playback applications, media editing applications, or any other application. In some embodiments, processor  102  may receive input signals from input component  110  and/or drive output signals through output component  112 . Processor  102  may load a user interface program (e.g., a program stored in memory  104  or another device or server accessible by device  100 ) to determine how instructions or data received via input component  110  may manipulate the way in which information is stored and/or provided to the user via output component  112 . 
     Electronic device  100  may also be provided with a housing  101  that may at least partially enclose one or more of the components of device  100  for protection from debris and other degrading forces external to device  100 . In some embodiments, housing  101  may include several walls that can define a cavity within which the various electronic components of device  100  can be disposed. In some embodiments, housing  101  can support various electronic components of device  100 , such as one or more input/output (“I/O”) components  110  and/or I/O components  112 , at the surfaces or within openings through the surfaces of the walls of housing  101 . In some embodiments, one or more of the components may be provided within its own housing component (e.g., input component  110  may be an independent keyboard or mouse within its own housing component that may wirelessly or through a wire communicate with processor  102 , which may be provided within its own housing component). Housing  101  can be formed from a wide variety of materials including, but not limited to, metals (e.g., steel, copper, titanium, aluminum, and various metal alloys), ceramics, plastics, glass, and any combinations thereof. Housing  101  may also help to define the shape or form of electronic device  100 . That is, the contour of housing  101  may embody the outward physical appearance of electronic device  100 . 
     Electronic device  100  is illustrated in  FIGS. 2 and 3  to be a laptop computer, although it is to be understood that electronic device  100  may be any type of electronic device as described herein. As shown in  FIGS. 2 and 3 , for example, housing  101  of electronic device  100  may be configured to provide two housing components coupled together by a hinge or clutch assembly. Particularly, housing  101  may include a base housing component  101   a  and a display housing component  101   b  coupled to one another by a hinge assembly  101   c , which may also be known as clutch assembly  101   c . Housing components  101   a ,  101   b , and  101   c  may be configured such that electronic device  100  may be “opened” for use (see, e.g.,  FIG. 2 ) by rotating display housing component  101   b  away from base housing component  101   a  in the direction of arrow O about hinge axis H of hinge assembly  101   c , and such that electronic device  100  may be “closed” (see, e.g.,  FIG. 3 ) by rotating display housing component  101   b  towards base housing component  101   a  in the direction of arrow C about hinge axis H. However, it should be noted that housing  101  of device  100  is only exemplary and need not include two substantially hexahedral portions coupled by a hinge. For example, in certain embodiments, the housing of device  100  could generally be formed in any other suitable shape, including, but not limited to, one or more housing components or portions that are substantially spherical, ellipsoidal, conoidal, octahedral, and any combinations thereof. 
     Base housing component  101   a  may include a top wall  121 , a bottom wall  126  opposite top wall  121 , and various side walls, such as front wall  122 , back wall  123  opposite front wall  122 , right wall  124 , and left wall  125  opposite right wall  124 . In some embodiments, one or more openings may be provided through one or more of the walls of housing component  101   a  to at least partially expose one or more components of electronic device  100 . For example, as shown in  FIG. 2 , at least one opening  131  may be provided through top wall  121  of base housing component  101   a  to at least partially expose an input component  110   a  of electronic device  100 . In some embodiments, as shown in  FIG. 2  for example, openings  141   a ,  141   b ,  141   c , and  141   d  may be provided through top wall  121  of base housing component  101   a  to at least partially expose respective output components  112   a ,  112   b ,  112   c , and  112   d  of electronic device  100 . 
     Likewise, display housing component  101   b  may include a top wall  161 , a bottom wall (not shown) opposite top wall  161 , and various side walls, such as front wall  162 , back wall  163  opposite front wall  162 , right wall  164 , and left wall  165  opposite right wall  164 . In some embodiments, one or more openings may be provided through one or more of the walls of housing component  101   b  to at least partially expose one or more components of electronic device  100 . For example, as shown in  FIG. 2 , an opening  151  may be provided through top wall  161  of display housing component  101   b  to at least partially expose an output component  112   c  of electronic device  100 . 
     Input component  110   a  is illustrated in  FIG. 2  to be a keyboard, although it is to be understood that input component  110   a , which may be exposed by opening  131  through top wall  121  of housing component  101   a , may be any type of input component  110  as described herein. Moreover, although output components  112   a ,  112   b ,  112   c , and  112   d  are illustrated in  FIG. 2  to be audio loudspeakers, it is to be understood that each one of output components  112   a ,  112   b ,  112   c , and  112   d , which may be exposed by respective openings  141   a - 141   d  through top wall  121  of housing component  101   a , may be any type of output component  112  as described herein. Similarly, although output component  112   c  is illustrated in  FIG. 2  to be a visual display, it is to be understood that output component  112   c , which may be exposed by opening  151  through top wall  161  of housing component  101   b , also may be any type of output component  112  as described herein. 
       FIG. 4  shows a detailed cross-sectional view of an exemplary audio loudspeaker assembly  412 , which may be similar to one or more of audio loudspeakers  112   a ,  112   b ,  112   c , and  112   d  of  FIG. 2 . As shown in  FIG. 4 , a magnetic air gap  477  may be formed between an under yoke  472  and a top plate  478 , using a permanent magnet  476 . Under yoke  472 , permanent magnet  476 , and top plate  478  may be collectively referred to herein as a magnet assembly  470 . 
     An electrically conductive voice coil  482  may be wound about or otherwise coupled to a former  488 . Coil  482  can be wound such that current flows in a +X-direction (e.g., out of the page) in portions  481  of coil  482 , and flows in a −X-direction (e.g., into the page) in portions  483  of coil  482 . 
     A frame  490  may be coupled to and may extend from magnet assembly  470 . A diaphragm or cone  492  may extend from a top portion  495  of frame  490  to a top portion of former  488  about axis A. Surround  494  may serve to suspend and maintain cone  492  and former  488  centered about and aligned with respect to top plate  478 , while also serving to allow axial movement along axis A of voice coil  482  and former  488  within magnetic air gap  477  of magnet assembly  470 . 
     When an alternating current (e.g., an audio electrical signal provided by an audio source of device  100 , such as an amplifier) is passed through voice coil  482  (e.g., as shown in  FIG. 4 ), coil  482  can be subjected to a force due to a stationary magnetic field in gap  477 . This is commonly referred to as the Lorentz force, and is the cross product of the stationary magnetic field in gap  477  and the current in coil  482 . This force can alternate sign (or direction), depending on the direction of current in coil  482 , and can displace cone  492  and surround  494  in the ±Z-directions to generate sound waves. 
     It is to be noted that, while loudspeakers may be shown in cross-section herein (e.g., because speakers may generally be cylindrically or rotationally symmetrical about an axis line or center line, such as axis A of  FIG. 4 ), one skilled in the art may appreciate the three-dimensional structure of such loudspeakers and that one or more of the loudspeakers described herein may not necessarily be axially symmetric. Moreover, although  FIG. 4  shows an axially symmetric loudspeaker having a magnet assembly disposed interior to coil  482 , it should be appreciated that an axially symmetric loudspeaker can instead have a magnet assembly disposed exterior to coil  482 . 
     As described above, a device can include two or more output components or loudspeakers positioned adjacent one another. In typical devices, the magnet assembly of each of these loudspeakers can be similarly oriented, and can provide the same magnetic phase.  FIG. 5  shows a cross-sectional of a pair of magnet assemblies  570  and  571  of corresponding loudspeakers (not shown) that can each be similar to magnet assembly  470 . As shown in  FIG. 5 , magnet assembly  570  can be oriented to provide a magnetic flux path  541 , and magnet assembly  571  can be oriented to provide a similar magnetic flux path  542  in the same magnetic phase as magnetic flux path  541 . However, because the magnetic phases of magnetic flux paths  541  and  542  are the same, any magnetic flux that may stray from each flux path may form a self-closing flux loop with the respective magnet assembly. As shown in  FIG. 5 , for example, stray magnetic flux Gc may form a self-closing flux loop  543 , and stray magnetic flux Gd may form a self-closing flux loop  544 . Flux loops  543  and  544  may interfere with any component positioned between magnet assemblies  570  and  571  that may have its own magnetic flux. For example, as shown in  FIG. 5 , a magnetically sensitive input device component  514   e  may be positioned in between magnet assemblies  570  and  571  in the same X-Y plane. In some embodiments, magnetically sensitive input component  514   e  may be a Hall effect sensor or any other suitable input component that may be affected by stray magnetic flux of another component. For example, as shown, magnetically sensitive input component  514   e  may have its own magnetic flux sensitivity direction  539  extending therethrough (e.g., in the −Z direction). The additional magnetic flux that may be added to flux  539  of magnetically sensitive input component  514   e  by stray fluxes Gc and Gd may adversely affect the performance of input component  514   e  (e.g., by destructive or constructive superposition of the stray flux densities). For example, a Hall Effect Sensor, which may use a magnet to flip a switch, can be either tripped prematurely or held in the tripped state if there is leakage flux present. 
     In order to reduce the effects of stray flux from adjacent loudspeaker input assemblies on any other magnetically sensitive device component, the two adjacent loudspeaker assemblies may be oriented in opposition magnetically. That is, a first loudspeaker assembly may be configured to be of the same acoustic phase as a proximal second loudspeaker assembly, but the first loudspeaker assembly may be configured to be of an opposite magnetic phase from the second loudspeaker assembly, such that the stray flux of each loudspeaker assembly may be guided into the magnetic flux of the other loudspeaker. This may redistribute flux away from any sensitive device disposed between the loudspeakers entirely, or may alter the direction of flux to a vector of lower sensitivity (e.g., as a sensitive component may only be sensitive to leakage in the −Z direction). 
       FIG. 6  shows a cross-sectional view of a pair of magnet assemblies  670  and  671  of corresponding loudspeakers (not shown) that can each be similar to magnet assemblies  270 ,  570 , and  571 . Rather than being oriented to produce magnetic flux paths in the same phase, however, magnet assemblies  670  and  671  can be oriented to produce opposite magnetic phases. As shown in  FIG. 6 , for example, magnet assembly  670  can be oriented to provide a magnetic flux path  638 , whereas magnet assembly  671  can be oriented to provide an opposite magnetic flux path  639 . Oriented in this manner, any magnetic flux that may stray from the flux paths may form a single closed flux loop. As shown in  FIG. 6 , for example, stray magnetic flux Ga and Gb may combine to form a single closed flux loop  640 . Because flux loop  640  is guided away from the area between magnet assemblies  670  and  671 , flux loop  640  does not interfere with magnetic flux of any component positioned between these magnet assemblies (e.g., a magnetically sensitive input device component  614   e  that may be similar to component  514   e , and that may be positioned between magnet assemblies  670  and  671  in the same X-Y plane) and may have magnetic flux sensitivity direction  649 . 
     Therefore, the effects of stray flux from adjacent loudspeaker input assemblies on another magnetically sensitive device component may be reduced by orienting the two adjacent loudspeaker assemblies in opposition magnetically. That is, a first loudspeaker assembly may be configured to be of the same acoustic phase as a proximal second loudspeaker assembly, but the first loudspeaker assembly may be configured to be of an opposite magnetic phase from the second loudspeaker assembly, such that the stray flux of each loudspeaker assembly may be guided into the magnetic flux of the other loudspeaker (e.g., as described with respect to  FIG. 6 ). By inverting the electrical contacts (e.g., see contacts  498  of  FIG. 4 ) of an audio source (e.g., see audio source  493  of  FIG. 4 ) of a device (e.g., device  100 ) with the electrical contacts of the electromagnetic coil of one of the two loudspeaker assemblies of opposite magnetic phase, the acoustic phase of each assembly may be preserved. Alternatively, an audio source signal (e.g., see signal  496  of  FIG. 4 ) may be inverted before being applied to one of the two loudspeaker assemblies. For example, as an alternative to inverting the electrical contact, a 180 degree inverter may invert the phase of the audio electrical signal being input. Alternatively, an amplifier or digital signal processing chain or audio source may do this before providing the signal to a loudspeaker input assembly. It is to be understood that an audio electrical signal may be filtered in one or more ways before being applied to each of the loudspeaker assemblies (e.g., loudspeaker assemblies  112   a  and  112   b , or the pair of loudspeaker assemblies corresponding to magnet assemblies  670  and  671 ). For example, loudspeaker assembly  112   a  may be a tweeter loudspeaker and loudspeaker assembly  112   a  may be a woofer loudspeaker, and different frequency ranges of an audio electrical signal may be applied to different ones of loudspeaker assemblies  112   a  and  112   b.    
     While there have been described systems and methods for reducing the effects of stray magnetic flux, it is to be understood that many changes may be made therein without departing from the spirit and scope of the invention. Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. It is also to be understood that various directional and orientational terms such as “up and “down,” “top” and “bottom,” “left” and “right,” “length” and “width,” “horizontal” and “vertical,” and the like are used herein only for convenience, and that no fixed or absolute directional or orientational limitations are intended by the use of these words. For example, the devices of this invention can have any desired orientation. If reoriented, different directional or orientational terms may need to be used in their description, but that will not alter their fundamental nature as within the scope and spirit of this invention. 
     Therefore, those skilled in the art will appreciate that the invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation.

Metadata:
Filing Date: 20130315
Publication Date: 20160105
Grant Date: 20160105
Priority Date: 20120610
Inventors: CROSBY JUSTIN D.
YAP DEREK J.
LEGGETT WILLIAM F.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R2499/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R31/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R3/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49005", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2209/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R3/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2209/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2209/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2499/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R9/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R5/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49005", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49005", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R31/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2499/15", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 48625796