PATENT DOCUMENT

Publication Number: US-10110991-B2
Application Number: US-201615203756-A
Country: US
Kind Code: B2

Title: Electronic device having mechanically out-of-phase speakers

Abstract:
An electronic device having several speaker modules that are acoustically in-phase and mechanically out-of-phase is disclosed. Embodiments include a pair of speaker modules mounted at respective ends of a lateral link, and the lateral link may be supported relative to a housing of the electronic device. The speaker modules may receive a same audio signal, and the audio signal may drive a first voicecoil in a first direction and a second voicecoil in a second direction. Accordingly, the speaker modules may be driven in mechanically different directions by the same audio signal, such that reactive forces cancel and/or mechanical energy is dissipate in the lateral link between the speaker modules. Other embodiments are also described and claimed.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing having a first wall and a second wall opposite of the first wall, the housing including a display and a manual input device; 
 a rigid connector extending in a lateral direction between a first end and a second end within the housing; 
 a first speaker module mounted on the rigid connector at the first end, the first speaker module including a first voicecoil, wherein the first voicecoil moves along a first axis in a first direction orthogonal to the lateral direction when driven by an audio signal to radiate sound through the first wall; 
 a second speaker module mounted on the rigid connector at the second end, the second speaker module including a second voicecoil, wherein the second voicecoil moves along a second axis in a second direction opposite to the first direction when driven by the audio signal to radiate sound through the second wall; and 
 a partition extending between the first wall and the second wall, wherein the partition includes a fulcrum between the housing and the rigid connector, and wherein the first axis and the second axis are laterally offset from each other on opposite sides of the fulcrum. 
 
     
     
       2. The electronic device of  claim 1 , wherein the audio signal includes an electrical current, wherein the electrical current travels through the first voicecoil about the first axis in the first direction, and wherein the electrical current flows through the second voicecoil about the second axis in the second direction. 
     
     
       3. The electronic device of  claim 1 , wherein the first speaker module includes a first front volume in fluid communication with an enclosure within the housing, wherein the second speaker module includes a second back volume, and wherein the first front volume and the enclosure have a combined spatial volume equal to the second back volume. 
     
     
       4. The electronic device of  claim 3 , wherein the enclosure is laterally between the first front volume and the second back volume within the housing. 
     
     
       5. The electronic device of  claim 4 , wherein the first speaker module includes a first back volume ported through a first slot in the first wall of the housing, and wherein the second speaker module includes a second front volume ported through a second slot in the second wall of the housing. 
     
     
       6. A electronic device, comprising:
 a housing including a display and a manual input device; 
 a lever extending laterally between a first end and a second end within the housing; 
 a first speaker module mounted on the lever, the first speaker module including a first voicecoil, wherein the first voicecoil moves along a first axis in a first direction when driven by an audio signal; 
 a second speaker module mounted on the lever, the second speaker module including a second voicecoil, wherein the second voicecoil moves along a second axis in a second direction opposite to the first direction when driven by the audio signal; and 
 a fulcrum between the housing and the lever, wherein the fulcrum is coupled to the lever between the first axis and the second axis. 
 
     
     
       7. The electronic device of  claim 6 , wherein the first speaker module is mounted on the lever at the first end and the second speaker module is mounted on the lever at the second end such that the first axis and the second axis are laterally offset from each other on opposite sides of the fulcrum. 
     
     
       8. The electronic device of  claim 7  further comprising:
 a first gasket between the housing and the first speaker module; and 
 a second gasket between the housing and the second speaker module, wherein the gaskets provide acoustically opaque paths to direct sound from respective speaker modules to a surrounding environment. 
 
     
     
       9. The electronic device of  claim 8 , wherein the first gasket and the second gasket are less stiff than the lever. 
     
     
       10. The electronic device of  claim 6 , wherein the fulcrum is coupled to the lever by a pin joint. 
     
     
       11. The electronic device of  claim 6 , wherein the first speaker module includes a first front volume in fluid communication with an enclosure within the housing, wherein the second speaker module includes a second back volume, and wherein the first front volume and the enclosure have a combined spatial volume equal to the second back volume. 
     
     
       12. The electronic device of  claim 11 , wherein the enclosure is laterally between the first front volume and the second back volume within the housing. 
     
     
       13. The electronic device of  claim 12 , wherein the first speaker module includes a first back volume ported through a first slot in a first wall of the housing, and wherein the second speaker module includes a second front volume ported through a second slot in a second wall of the housing opposite of the first wall. 
     
     
       14. The electronic device of  claim 6  further comprising:
 a third speaker module mounted on the lever at the first end adjacent to the first speaker module, wherein the third speaker module includes a third voicecoil, and wherein the third voicecoil moves along a third axis in the second direction when driven by the audio signal; and 
 a fourth speaker module mounted on the lever at the second end adjacent to the second speaker module, wherein the fourth speaker module includes a fourth voicecoil, and wherein the fourth voicecoil moves along a fourth axis in the first direction when driven by the audio signal.

Description:
BACKGROUND 
     Field 
     Embodiments related to electronic devices having mechanically out-of-phase speaker modules are disclosed. More particularly, embodiments related to portable electronic devices having several voicecoils that are driven in opposite directions by a same audio signal are disclosed. 
     Background Information 
     Electronic devices sometimes include a pair of loudspeakers to generate sound from electrical audio signals. Typically, the pair of loudspeakers are located in a common enclosure and are both acoustically and mechanically in-phase. More particularly, the loudspeakers are acoustically in-phase because they generate sound from a same audio signal, and the loudspeakers are mechanically in-phase because the same audio signal drives respective diaphragms of the loudspeakers simultaneously in the same direction. 
     SUMMARY 
     Electronic devices having acoustically and mechanically in-phase loudspeakers may experience unintended transmission of forces from the speaker modules into the system housing. In fact, such force transmission may unexpectedly increase as a design consequence of optimizing loudspeaker acoustic output. For example, as loudspeakers are miniaturized, the mass of the loudspeaker moving parts (e.g., a voicecoil) may be increased to achieve a same amount of sound output. The increased diaphragm mass, however, when moved by the voicecoil of the loudspeaker, may apply a greater reactive force to the stationary components of the loudspeaker, e.g., a magnet assembly of the loudspeaker. The reactive force may then be transmitted as a parasitic force into the loudspeaker system as a whole. Consequently, the transmitted reactive force may result in components of the electronic device rattling, creating what is referred to as a “rub and buzz” problem, i.e., increased intermittent contact from other components in the system. 
     In an embodiment, an electronic device having a display and a manual input device, e.g., a laptop computer, includes mechanically out-of-phase loudspeakers to limit parasitic force transmission. The electronic device may include a housing having a first wall and a second wall opposite of the first wall. The electronic device may include a rigid connector extending in a lateral direction within the housing between a first end and a second end. A first speaker module may be mounted on the rigid connector at the first end, and a second speaker module may be mounted on the rigid connector at the second end. Each speaker module may include a respective voicecoil, and the voicecoils may be mechanically out-of-phase. For example, an electrical current of an audio signal may travel through a first voicecoil of the first speaker module about a first axis in a first direction, and the electrical current may flow through a second voicecoil of the second speaker module about a second axis in a second direction. Thus, the first voicecoil may move along the first axis in the first direction orthogonal to the rigid connector when driven by the audio signal, and the second voicecoil of the second speaker module may move along the second axis in the second direction opposite to the first direction when driven by the audio signal. Accordingly, the first speaker module may radiate sound through the first wall of the housing, and the second speaker module may radiate sound through the second wall of the housing. The reactive forces from the moving voicecoils may be in opposite directions, and thus, a net reactive force may trend toward zero. 
     The first speaker module of the electronic device may include a first front volume in fluid communication with an enclosure within the housing. The second speaker module may include a second back volume adjacent to the enclosure. For example, the enclosure may be laterally between the first front volume and the second back volume within the housing. In an embodiment, the first front volume and the enclosure have a combined volume equal to the second back volume. Furthermore, the first speaker module may include a first back volume ported through a first slot in the first wall of the housing, and the second speaker module may include a second front volume ported through a second slot in the second wall of the housing. Thus, sound may radiate into a surrounding environment from a front volume of one loudspeaker and from a back volume of another loudspeaker. 
     In an embodiment, an electronic device, e.g., a laptop computer, includes a housing having a display and a manual input device. The electronic device may include a lever extending laterally between a first end and a second end within the housing. Furthermore, a fulcrum may extend between the housing and the lever, and the fulcrum may be coupled to the lever between the first end and the second end. For example, the fulcrum may be coupled to the lever by a pin joint. Accordingly, a first speaker module may be mounted on the lever on one side of the fulcrum and a second speaker module may be mounted on the lever on another side of the fulcrum. That is, the first speaker module may be mounted on the lever at the first end and the second speaker module may be mounted on the lever at the second end such that a first axis of the first speaker module is laterally offset from a second axis of the second speaker module on opposite sides of the fulcrum. As described above, the first speaker module and the second speaker module may be mechanically out-of-phase such that a first voicecoil of the first speaker module moves along the first axis in a first direction when driven by an audio signal, and a second voicecoil of a second speaker module moves along the second axis in a second direction opposite to the first direction when driven by the audio signal. Thus, reactive forces from the speaker modules may be in opposite directions to cancel and reduce a net reactive force applied to the housing. 
     The electronic device may include a first gasket between the housing and the first speaker module, and a second gasket between the housing and the second speaker module. The gaskets may be acoustically rigid to provide paths to direct sound from respective speaker modules to a surrounding environment. In addition to being acoustically rigid, the gaskets may be soft. For example, the gaskets may be less stiff than the lever and/or spongy. Thus, the gaskets may absorb and dissipate energy from the moving speaker modules to further reduce a net reactive force applied to the housing by compliant mounting. 
     The electronic device may include pairs of speaker modules on each side of the fulcrum. For example, a third speaker module may be mounted on the lever at the first end adjacent to the first speaker module. The third speaker module may be mechanically out-of-phase with the first speaker module, i.e., a third voicecoil of the third speaker module may move along a third axis in the second direction when driven by the audio signal. Similarly, a fourth speaker module may be mounted on the lever at the second end adjacent to the second speaker module. The fourth speaker module may be mechanically out-of-phase with the second speaker module, i.e., a fourth voicecoil of the fourth speaker module may move along a fourth axis in the first direction when driven by the audio signal. Thus, a net moment at the joint between the lever and the fulcrum, which is caused by the several reactive forces of the speaker modules, may trend toward zero. 
     In an embodiment, an electronic device having a housing that includes a display and a manual input device may further include a cantilever extending laterally within the housing from an anchor to a first end. A first speaker module may be mounted on the cantilever at the first end, and the first speaker module may include a first voicecoil. Thus, the first voicecoil may move along a first axis in a first direction orthogonal to the cantilever when driven by an audio signal. The electronic device may further include a second cantilever extending laterally within the housing from a second anchor in an opposite direction of the cantilever to a second end. The second speaker module may be mounted on the second cantilever at the second end, the second speaker module may include a second voicecoil. Thus, the second voicecoil may move along a second axis in a second direction opposite to the first direction when driven by the audio signal. Accordingly, the cantilevers may absorb and dissipate energy from the speaker modules. 
     The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial view of an electronic device in accordance with an embodiment. 
         FIG. 2  is a sectional view of a speaker module of an electronic device in accordance with an embodiment. 
         FIG. 3  is a sectional view of an electronic device having speaker modules mounted on a rigid connector in accordance with an embodiment. 
         FIG. 4  is a sectional view of an electronic device having a ported front volume of a speaker module in accordance with an embodiment. 
         FIG. 5  is a sectional view of an electronic device having speaker modules mounted on a lever in accordance with an embodiment. 
         FIG. 6  is a sectional view of an electronic device having pairs of speaker modules on opposite sides of a fulcrum in accordance with an embodiment. 
         FIG. 7  is a sectional view of an electronic device having speaker modules mounted on cantilevers in accordance with an embodiment. 
         FIG. 8  is a schematic view of an electronic device in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments describe electronic devices having mechanically out-of-phase speaker modules. Some embodiments are described with specific regard to integration within portable electronic devices such as laptop computers. The embodiments are not so limited, however, and certain embodiments may also be applicable to other uses. For example, mechanically out-of-phase speaker modules may be incorporated into other devices and apparatuses, including desktop computers, tablet computers, mobile devices, wearable computers, wristwatch devices, or motor vehicles, to name only a few possible applications. 
     In various embodiments, description is made with reference to the figures. Certain embodiments, however, may be practiced without one or more of these specific details, or in combination with other known methods and configurations. In the following description, numerous specific details are set forth, such as specific configurations, dimensions, and processes, in order to provide a thorough understanding of the embodiments. In other instances, well-known processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the description. Reference throughout this specification to “one embodiment,” “an embodiment,” or the like, means that a particular feature, structure, configuration, or characteristic described is included in at least one embodiment. Thus, the appearance of the phrase “one embodiment,” “an embodiment,” or the like, in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The use of relative terms throughout the description, such as “front” and “back” may denote a relative position or direction. For example, a volume on one side of a diaphragm of a speaker module may be described as being a “front volume” and a volume on an opposite side of the diaphragm may be described as being a “back volume.” Nonetheless, such terms are not intended to limit the use of the speaker module to a specific configuration described in the various embodiments below. 
     In an aspect, an electronic device includes mechanically out-of-phase speaker modules. The speaker modules may be laterally separated from each other within a housing of the electronic device, such that an audio signal drives a voicecoil of one speaker module in a first direction orthogonal to a lateral plane and the same audio signal drive a voicecoil of the other speaker module in a second direction opposite of the first direction. The laterally separated speaker modules may radiate sound through opposite walls of the housing, and the speaker modules may be connected by an intervening lateral link. For example, the speaker modules may be mounted at respective ends of a rigid connector, a lever coupled to a fulcrum, or a cantilever. Furthermore, the speaker modules may be allowed to move relative to the housing, e.g., by mounting a soft gasket between the housing and the speaker module, effectively decoupling the linked speaker modules from the housing. Thus, when the speaker modules reproduce sound from the audio signal, parasitically transmitted reactive forces may cancel and/or be dissipated in the intervening link rather than being transmitted into the housing. Accordingly, rub and buzz from the components of the electronic device may be reduced. 
     Referring to  FIG. 1 , a pictorial view of an electronic device is shown in accordance with an embodiment. Electronic device  100  may be a portable device, such as a laptop computer. Accordingly, electronic device  100  may include a housing  102  having a first wall  104  and a second wall  106 . First wall  104  may be a front, forward, or upward facing wall, and second wall  106  may be a back, rearward, or downward facing wall. More particularly, second wall  106  may be opposite of first wall  104 , and first wall  104  and second wall  106  may include respective outward surfaces facing opposite directions. Electronic device  100  may include a display  108  and a manual input device  110  integrated in housing  102 . In an embodiment, manual input device  110  includes an alphanumeric input, a touchpad, etc. 
     Referring to  FIG. 2 , a sectional view of a speaker module of an electronic device is shown in accordance with an embodiment. Electronic device  100  may include one or more speaker modules  200 . Speaker modules  200  may be located in a common enclosure, such as within housing  102 , and may include a loudspeaker frame mounted on a base  202 . For example, base  202  may include an inner surface of first wall  104  or second wall  106  of housing  102  and/or a system component within housing  102 , such as a lateral link as described below. 
     In an embodiment, speaker module  200  includes a motor assembly having moving and stationary parts. A stationary portion of the motor assembly may include magnetic parts such as a magnet  204 , a top plate  206 , and a yoke  208 . The magnetic parts form a magnetic circuit through an intervening gap, e.g., laterally between top plate  206  and yoke  208 . A moving portion may include a voicecoil  210  suspended within the gap such that an electrical current flowing through the voicecoil  210  generates a Lorentz force to displace the moving portion relative to the stationary portion of the motor assembly. More particularly, voicecoil  210  may be attached to a diaphragm  212 , and diaphragm  212  may be suspended relative to the stationary portion by a surround  214 , such that the Lorentz force moves the diaphragm  212  relative to the stationary portion to generate sound. 
     The stationary portion of speaker module  200  includes the magnet assembly of the motor assembly as well as other stationary parts attached to speaker module  200 . Accordingly, the stationary portion of speaker module  200  is associated with a combined mass, M s . Similarly, the moving portion of speaker module  200  having voicecoil  210  and diaphragm  212  is associated with a combined mass, M m . These component masses are coupled by surround  214  having a spring coefficient, K m . Accordingly, when the moving portion is driven to generate sound, a reactive force is transmitted through surround  214  to the stationary portion and into base  202 . This parasitic reactive force may then be transmitted through base  202  into housing  102  and/or other components of electronic device  100  that are coupled to base  202 . Furthermore, the parasitic force may be multiplied when several speaker modules  200  are attached to base  202  and driven mechanically in-phase. 
     It is considered that the parasitic force from several speaker modules  200  may be modulated by placing the drivers acoustically in-phase and mechanically out-of-phase. For example, a pair of speaker modules  200  attached to base  202  may be physically flipped relative to one another, or their respective voicecoil  210  windings may be wound in opposite directions, such that the drivers move in different directions when driven by a same audio signal. Accordingly, the drivers may be acoustically in-phase because they generate the same sound from the same audio signal, and the drivers may be mechanically out-of-phase because their diaphragms  212  move and displace mechanical pressure in opposite directions, e.g., upward versus downward. As a result, a reactive force transmitted to base  202  from a first speaker may be upward when the corresponding diaphragm  212  is driven downward, and a reactive force transmitted to base  202  from a second speaker may be downward when the corresponding diaphragm  212  is simultaneously driven upward. That is, the respective reactive forces from each speaker module  200  may act on base  202  in different directions such that a net reactive force on base  202  is reduced. Given that base  202  may not be perfectly rigid, however, and given that the axes of motion of the speaker modules  200  may be separated from each other by a distance, an acoustically in-phase and mechanically out-of-phase speaker module assembly may not experience pure force cancellation. For example, a moment may be transmitted to base  202  by laterally separated speaker modules  200 . Thus, parasitic force transmission from an acoustically in-phase and mechanically out-of-phase speaker module  200  assembly may be further optimized. 
     Referring to  FIG. 3 , a sectional view of an electronic device having speaker modules mounted on a rigid connector is shown in accordance with an embodiment. Electronic device  100  may include a pair of speaker modules  200  mounted on a lateral link, e.g., a rigid connector  302 , within housing  102 . For example, rigid connector  302  may extend in a lateral direction, e.g., along a lateral plane  304 , between a first end  306  or edge and a second end  308  or edge. Accordingly, rigid connector  302  may have a profile of a beam or elongated member with first end  306  and second end  308 , or alternatively, rigid connector  302  may have a profile of a plate or flat member with a first edge and second edge. More particularly, rigid connector  302  may include laterally separated mounting locations for attaching a pair of speaker modules  200  at separate locations along lateral plane  304 . Thus, speaker modules  200  mounted on rigid connector  302  may include respective voicecoils  210  that oscillate on respective axes that are non-coaxial, e.g., laterally offset from one another. 
     The relative orientation of speaker modules  200  may further be defined with respect to a relative orientation between the axes and the diaphragms  212  of the modules. For example, the respective axes of the speaker modules  200  may be parallel to each other. Similarly, a plane of the respective diaphragms  212  of the speaker modules  200  may be parallel to each other. In an embodiment, the diaphragms  212  define planes that are coplanar, i.e., the diaphragms  212  are arranged at a same axial location relative to their axes of motion, albeit at laterally separated locations along the same plane. 
     A rigidity of rigid connector  302  may be qualitatively defined. For example, rigid connector  302  may be formed from a material having a stiffness greater than a stiffness of a material forming housing  102 . Accordingly, rigid connector  302  may be less susceptible than housing  102  to bending from a moment generated by reactive forces of speaker modules  200 . 
     In an embodiment, electronic device  100  includes a first speaker module  310  mounted on rigid connector  302  at first end  306 . First speaker module  310  may have a construction such as that described above, e.g., may include a corresponding voicecoil  210 . As indicated by the electrical flux markers in  FIG. 3 , an audio signal  312 , which may be an electrical current, may travel through voicecoil  210  of first speaker module  310  about a first axis  314  in a first direction. That is, voicecoil  210  of first speaker module  310  is illustrated having a right-handed rotational direction around first axis  314  such that the first direction is upward along first axis  314 . Furthermore, first axis  314  may be orthogonal to the lateral direction of lateral plane  304  along which rigid connector  302  extends. Accordingly, when driven by audio signal  312 , voicecoil  210  of first speaker module  310  may move along first axis  314  in the first direction to radiate a sound  316 , e.g., downward, through one or more slots  318  in first wall  104  of housing  102 . A thickness of the walls of housing  102  having slots  318  used for sound radiation may be limited to a predetermined range. For example, a thickness of the slotted first wall  104  region may be less than 2 mm. A concomitant reactive force may be transmitted through first speaker module  310  upward and orthogonal to rigid connector  302 . 
     Note that first wall  104  of housing  102  is illustrated as being below first speaker module  310  in  FIG. 3 , as opposed to being above speaker module  200  as shown in  FIG. 1 . This permutation clarifies that the directionality associated with speaker modules  200  of electronic device  100  is described by way of example and not limitation. That is, the relative orientations, and the absolute orientations, are of the essence of this description. 
     Electronic device  100  may include a second speaker module  320  mounted on rigid connector  302  at second end  308 . Second speaker module  320  may be acoustically in-phase and mechanically out-of-phase with first speaker module  310 . For example, as indicated by the electrical flux markers in  FIG. 3 , electrical current of audio signal  312  may be reversed through second speaker module  320  to travel through a corresponding voicecoil  210  of second speaker module  320  about a second axis  322  in a second direction. The second direction of second speaker module  320  may be opposite to the first direction of first speaker module  310  described above. That is, voicecoil  210  of second speaker module  320  may have a right-handed rotational direction around a second axis  322  such that the second direction is downward along second axis  322 . Furthermore, second axis  322  may be orthogonal to the lateral direction of lateral plane  304 . Accordingly, when driven by audio signal  312 , voicecoil  210  of second speaker module  320  may move along second axis  322  in the second direction to radiate sound  316  upward through one or more slots  318  in second wall  106  of housing  102 . 
     It will be appreciated that speaker modules  200  having respective voicecoils  210  around parallel and laterally separated axes may also be driven mechanically out-of-phase by reversing a coil direction of their respective voicecoils  210 . For example, rather than reversing the signals to travel in opposite directions along the axes, as described above, a voicecoil  210  of first speaker module  310  may be wound around first axis  314  in a right-handed direction, and a voicecoil  210  of second speaker module  320  may be wound around second axis  322  in a left-handed direction. Thus, an electrical signal passing through the respective voicecoils  210  in a same axial direction, e.g., upward, may react with corresponding magnet assemblies of the speaker modules to generate opposing voicecoil  210  and diaphragm  212  movements. 
     Speaker modules  200  having respective voicecoils  210  around parallel and laterally separated axes may also be driven mechanically out-of-phase by reversing the magnetic system associated with each voicecoil to alter a phase of the speaker module. For example, respective voicecoils  210  may both have a same rotational direction, e.g., right-handed, around a respective axis, but a magnetic flux through the respective magnetic systems may be reversed. That is, a magnetic flux through a center magnet located coaxially with a first voicecoil may be upward, i.e., a north pole of the center magnet may be above a south pole of the center magnet, and a magnetic flux through a center magnet located coaxially with a second voicecoil may be downward. Accordingly, an electrical signal passing through the respective voicecoils in a same direction, e.g., upward and in a right-handed rotational direction, may generate movement of the first voicecoil in a first direction and may generate movement of the second voicecoil in a second direction opposite to the first direction. Accordingly, flipping the magnetic system may generate acoustically in-phase and mechanically out-of-phase motion of a pair of speaker modules  200 . 
     Rigid connector  302  may be mounted within housing  102 , as shown in  FIG. 3 , or alternatively, rigid connector  302  may be incorporated in housing  102 . For example, rigid connector  302  may be a portion of first wall  104  or second wall  106  upon which first speaker module  310  and second speaker module  320  are mounted. The portion of housing  102  defining rigid connector  302  may be more rigid than surrounding portions of housing  102 . For example, rigid connector  302  may be a metal or glass-filled polymer insert embedded within the housing  102  wall. Accordingly, rigid connector  302  may limit reactive forces transmitted from speaker modules  200  to housing  102  even when rigid connector  302  forms a portion of housing  102 . 
     Rigid connector  302  may be supported relative to housing  102  at first end  306  and/or second end  308 . For example, electronic device  100  may include a first gasket  340  between housing  102  and first speaker module  310  and a second gasket  350  between housing  102  and second speaker module  320 . In an embodiment, each gasket is formed from a material that is acoustically opaque and softer than the material used to form rigid connector  302 . For example, first gasket  340  or second gasket  350  may include a polyurethane foam ring having a central passage to direct sound  316  from respective speaker modules  200  through slots  318  in the housing walls to a surrounding environment outside of housing  102 . Electronic device  100  may also include one or more spacers, e.g., grommets, formed from a material softer than the material used to form rigid connector  302 , and the spacers may be located between speaker modules  200  and housing  102 . Accordingly, rigid connector  302  may be supported relative to housing  102  by one or more soft links that allow speaker modules  200  to move along respective axes orthogonal to lateral plane  304  while remaining constrained relative to each other by rigid connector  302 . In essence, the speaker module  200  assembly described above may decouple speaker modules  200  from housing  102  to reduce excitation of system Eigen modes that can worsen rub and buzz of the system. 
     In an embodiment, first speaker module  310  and second speaker module  320  may be oriented similarly. For example, both speaker modules  200  may have a front volume above diaphragm  212  of the speaker module  200 . In the embodiment illustrated in  FIG. 3 , a first front volume  323  of first speaker module  310  may be within a common back volume  325  of the speaker modules  200 . That is, sound  316  may be emitted outward through housing  102  from a first back volume  324  of first speaker module  310 , and sound  316  may be transmitted into the enclosed volume within housing  102  from first front volume  323  of first speaker module  310 . By contrast, a second front volume  326  of second speaker module  320  may be directed toward the surrounding environment and a second back volume  328  of second speaker module  320  may be within the common back volume  325  of the speaker modules  200 . Thus, sound  316  may be emitted outward through housing  102  from second front volume  326  of second speaker module  320 , and sound  316  may be transmitted into the enclosed volume within housing  102  from second back volume  328  of second speaker module  320 . 
     In an embodiment, first front volume  323  defines a portion of common back volume  325  and second back volume  328  defines another portion of common back volume  325 . Furthermore, the defined portions of common back volume  325  may be acoustically separated from each other by one or more partitions  330 . For example, a partition  330  may extend across common back volume  325  within housing  102  to acoustically isolate first speaker module  310  from second speaker module  320 . That is, first front volume  323  may be located on one side of partition  330  and second back volume  328  may be located on another side of partition  330 . Partition  330  may be located such that first front volume  323  and second back volume  328  occupy equal spatial volumes. As described below, however, first front volume  323  and second back volume  328  may have different sizes. 
     Referring to  FIG. 4 , a sectional view of an electronic device having a ported front volume of a speaker module is shown in accordance with an embodiment. Electronic device  100  may include first speaker module  310  and second speaker module  320  configured essentially as described above. For example, first speaker module  310  may include first back volume  324  separated from first front volume  323  by first gasket  340  such that sound  316  generated by diaphragm  212  of first speaker module  310  is directed through first back volume  324 . More particularly, first back volume  324  may be ported through one or more slots  318  in first wall  104  of housing  102  outward into a surrounding environment. Similarly, second speaker module  320  may include second front volume  326  separated from second back volume  328  by second gasket  350  such that sound  316  generated by diaphragm  212  of second speaker module  320  is directed through second front volume  326 . More particularly, second front volume  326  may be ported through a slot  318  in second wall  106  of housing  102  outward into the surrounding environment. 
     A laterally extending link connecting first speaker module  310  to second speaker module  320  may be present within housing  102 . Such a link, however, is not shown in  FIG. 4  to ease an understanding of the concept being illustrated. More particularly,  FIG. 4  illustrates an embodiment of a partitioned common back volume  325  within housing  102  that may be used in combination with a speaker module lateral link as described herein. 
     In an embodiment, first front volume  323  of first speaker module  310  is placed in fluid communication with an enclosure  402  within housing  102 . For example, first front volume  323  may be located in a space between first speaker module  310  and second wall  106  of housing  102 , and enclosure  402  may be laterally offset from first front volume  323  to occupy a space between second wall  106  and first wall  104  of housing  102 . More particularly, enclosure  402  may be laterally between first front volume  323  and second back volume  328  within housing  102 . Thus, sound  316  generated by first speaker module  310  may be ported laterally around a sub-partition  330  into enclosure  402  on one side of partition  330 , and sound  316  generated by second speaker module  320  may radiate into second back volume  328  on another side of partition  330 . Sound  316  may be ported from first front volume  323  into a volume contained by enclosure  402  through a port in sub-partition  404 . 
     In an embodiment, a combined spatial volume occupied by first front volume  323  and enclosure  402  may be equal to a spatial volume occupied by second back volume  328 . That is, common back volume  325  within housing  102  may be equally apportioned between first speaker module  310  and second speaker module  320 . Apportionment of common back volume  325  may not be necessary, however, and in some embodiments, there may be no partition  330  or separation between first front volume  323  and second back volume  328  within housing  102 . 
     Embodiments of electronic device  100  described below have a lateral link between speaker modules  200  similar to rigid connector  302 . In some embodiments, however, the lateral link may not be perfectly rigid, and thus, parasitic reactive forces may be transmitted through the lateral link. Certain structural configurations of the lateral link may be employed to dissipate such reactive forces and limit the transmission of parasitic forces into housing  102 . 
     Referring to  FIG. 5 , a sectional view of an electronic device having speaker modules mounted on a lever is shown in accordance with an embodiment. Electronic device  100  may include housing  102  having display  108  and manual input device  110 . In an embodiment, a lateral link supporting several speaker modules  200  of electronic device  100  may include a lever  502  extending laterally between first end  306  and second end  308 . More particularly, lever  502  may include an elongated member or a flat member extending laterally within housing  102  between opposing ends or edges. First speaker module  310  may be mounted on lever  502 , e.g., near first end  306 . Accordingly, a respective voicecoil  210  of first speaker module  310  may move along first axis  314  in a first direction when driven by an audio signal  312 . Similarly, second speaker module  320  may be mounted on lever  502 , e.g., near second end  308 . Accordingly, a respective voicecoil  210  of second speaker module  320  may move along second axis  322  in a second direction opposite to first direction when driven by the same audio signal  312  driving first speaker module  310 . Accordingly, first speaker module  310  and second speaker module  320  mounted on lever  502  may be mechanically out-of-phase because a positive current applied to a positive lead of first speaker module  310  produces motion in the first direction, and the positive current applied to a positive lead of second speaker module  320  produces motion in the second direction. 
     Lever  502  of electronic device  100  may be attached to a fulcrum  504 . More particularly, fulcrum  504  may extend between housing  102 , e.g., second wall  106  of housing  102 , and lever  502 . Similarly, fulcrum  504  may extend between lever  502  and first wall  104  of housing  102 . Fulcrum  504  may have a post structure, e.g., an elongated columnar structure, or fulcrum  504  may have a wall structure, e.g., fulcrum  504  may form a portion of partition  330  within common back volume  325  of housing  102 . 
     In an embodiment, fulcrum  504  is attached to lever  502  between first end  306  and second end  308 . For example, first speaker module  310  may be mounted on lever  502  at the first end  306  and second speaker module  320  may be mounted on lever  502  at the second end  308 . Thus, second axis  322  may be laterally offset from first axis  314  on opposite sides of fulcrum  504 . When respective voicecoils  210  of first speaker module  310  and second speaker module  320  move in opposite directions, opposing reactive forces may be transmitted to lever  502 . Thus, lever  502  may pivot about an end of fulcrum  504 . Such pivoting may dissipate energy within lever  502  and/or fulcrum  504 , rather than transmit the energy into housing  102 . In essence, motion of the speaker modules  200  may be decoupled from housing  102  as lever  502  pivots in a seesaw action about fulcrum  504 . 
     In an embodiment, first speaker module  310  and second speaker module  320  may be laterally separated from fulcrum  504  by equal lengths. For example, a distance between a vertical axis running through fulcrum  504  and both first axis  314  and second axis  322  may be equal. Accordingly, a reactive moment at a joint between lever  502  and fulcrum  504  caused by a reactive force of first speaker module  310  may have a same magnitude as a reactive moment at the joint caused by a reactive force of second speaker module  320 . In some embodiments, the lateral distances between fulcrum  504  and the speaker module  200  axes may differ. 
     A joint between lever  502  and fulcrum  504  may constrain relative movement between lever  502  and fulcrum  504  about one or more planes or axes. For example, lever  502  and fulcrum  504  may be integrally formed such that pivoting of lever  502  about fulcrum  504  occurs mainly through material strain at the joint. That is, when the joint is a simply supported fixed support, movement between lever  502  and fulcrum  504  at the joint may be fixed in all translational directions and rotational directions. In an embodiment, however, the joint between lever  502  and fulcrum  504  includes a pin joint  506 . By way of example, pin joint  506  may include a pin inserted in respective holes of lever  502  and fulcrum  504 , such as may be used in a seesaw structure. Pin joint  506  may allow rotation between lever  502  and fulcrum  504  about an axis of the pin, but may fix lever  502  relative to fulcrum  504  in all translational directions. 
     Electronic device  100  may include energy absorbing elements between speaker modules  200  and housing  102 . For example, first gasket  340  may be located between first speaker module  310  and housing  102 . Similarly, second gasket  350  may be located between housing  102  and second speaker module  320 . As described above, the gaskets may provide acoustically opaque pads to direct sound  316  from respective speaker modules  200  to a surrounding environment. The gaskets may also absorb mechanical energy from the speaker modules  200  as they move along their respective axes. For example, the gaskets may be softer, i.e., less stiff than, lever  502 , and thus, the gaskets may provide soft end boundary conditions for the speaker module assembly. In an embodiment, the gaskets are spongy. For example, first gasket  340  or second gasket  350  may include a foam material. Alternatively, gaskets may include a rubber material or another elastomeric material that resiliently compresses when squeezed between a speaker module  200  and housing  102 . Accordingly, gaskets may both absorb mechanical energy to decouple speaker module  200  from housing  102 , and may create an acoustically opaque path for sound  316  propagation. Gaskets may be between both sides of speaker module  200  and walls  104 ,  106  of housing  102  (not shown). 
     It will be appreciated that electronic device  100  having a lateral link including a lever  502  and a fulcrum  504  may incorporate any of the speaker orientations or front and back volume configurations described above with respect to  FIGS. 3-4 . For example, electronic device  100  illustrated in  FIG. 5  may include first speaker module  310  having first front volume  323  in fluid communication with enclosure  402  within housing  102 . Second speaker module  320  may include second back volume  328 , and first front volume  323  and enclosure  402  may have a combined spatial volume equal to a spatial volume occupied by second back volume  328 . Similarly, enclosure  402  may be laterally between first front volume  323  and second back volume  328  within housing  102 . Furthermore, first speaker module  310  may include first back volume  324  ported through slot  318  in first wall  104  of housing  102 , and second speaker module  320  may include second front volume  326  ported through one or more slots  318  in second wall  106  of housing  102 . Second wall  106  may be opposite of first wall  104 , e.g., second wall  106  may be an upper wall of a laptop computer and first wall  104  may be a lower wall of the laptop computer. In the interest of brevity, it will be appreciated that such speaker and volume configurations of electronic device  100  may also be used in combination with the embodiments described below with respect to  FIGS. 6-7 . More particularly, those embodiments may incorporate any of the features of the embodiments described above. 
     Referring to  FIG. 6 , a sectional view of an electronic device having pairs of speaker modules on opposite sides of a fulcrum is shown in accordance with an embodiment. As described above, electronic device  100  having speaker modules  200  mounted on a rigidly supported lateral link may reduce a net reactive force transmitted to housing  102 . The reactive forces of each speaker module  200  within housing  102 , however, may generate reactive moments at the rigid support. For example, with respect to speaker modules  200  mounted on lever  502  rigidly supported by fulcrum  504 , a reactive force from a speaker module  200  on a first side of the joint between lever  502  and fulcrum  504  may generate a moment in a first direction (positive or negative) and a reactive force from a speaker module  200  on a second side of the joint may generate a moment in a second direction opposite to the first direction. 
     In an embodiment, pairs of speaker modules  200  are mounted on lever  502  on each side of the joint between lever  502  and fulcrum  504 . For example, as described above, first speaker module  310  may be mounted on lever  502  at first end  306  laterally separated from fulcrum  504 . First speaker module  310  may drive sound  316  through second wall  106  of housing  102  in an upward direction. Thus, a parasitic reactive force from first speaker module  310  may be downward, causing a negative moment at the joint between lever  502  and fulcrum  504 . To offset this moment, a third speaker module  602  may be mounted on lever  502  at first end  306  adjacent to first speaker module  310 . Third speaker module  602  may include a third motor assembly having a respective voicecoil  210  that moves along a third axis  604  in a direction opposite to a respective voicecoil  210  of first speaker module  310  when driven by audio signal  312 . More particularly, first speaker module  310  and third speaker module  602  may be acoustically in-phase and mechanically out-of-phase, and thus, the reactive force from third speaker module  602  may generate a positive moment at the joint between lever  502  and fulcrum  504  to counteract the moment generated by first speaker module  310 . Accordingly, a sum of the moments generated by first speaker module  310  and third speaker module  602  at the joint may be zero, or nearly zero. 
     Second speaker module  320  on an opposite side of fulcrum  504  from first speaker module  310  may similarly be paired with a counterpart speaker module  200  to create a zero-sum of moments at the joints between lever  502  and fulcrum  504 . More particularly, electronic device  100  may include a fourth speaker module  606  having a respective voicecoil  210  that moves along a fourth axis  608  when driven by audio signal  312 . Fourth speaker module  606  may be mounted on lever  502  at second end  308  adjacent to second speaker module  320 . Furthermore, second speaker module  320  and fourth speaker module  606  may be acoustically in-phase and mechanically out-of-phase such that the reactive force from second speaker module  320  is in a direction along second axis  322  and the reactive force from fourth speaker module  606  is in an opposite direction along fourth axis  608 . The reactive forces from second speaker module  320  and fourth speaker module  606  may generate opposing moments at the joint between lever  502  and fulcrum  504 . Accordingly, a sum of the moments generated by second speaker module  320  and fourth speaker module  606  at the joint may be zero, or nearly zero. 
     Note that speaker modules  320  on opposite sides of the joint between lever  502  and fulcrum  504  may also generate canceling moments. For example, first speaker module  310  and second speaker module  320  may be equidistant from the joint between lever  502  and fulcrum  504 . Similarly, third speaker module  602  and fourth speaker module  606  may be equidistant from the joint. Thus, the opposing speaker modules, when moving in the same direction, i.e., when mechanically in-phase, on opposite sides of the joint, may generate opposing moments at the joint. As such, a net moment at the joint of the speaker module assembly having several pairs of speakers mounted at opposite ends of lever  502  may be zero, and thus, parasitic force into the housing  102  may be limited. 
     Referring to  FIG. 7 , a sectional view of an electronic device having speaker modules mounted on cantilevers is shown in accordance with an embodiment. Electronic device  100  can include a lateral link having one or more speaker modules  200  on only one side of an attachment to housing  102 . For example, the lateral link may include an individual driver mounted on a flexible cantilever  702 . 
     In an embodiment, electronic device  100  includes a cantilever  702  extending laterally within housing  102  from an anchor  704  to a first end  306 . Anchor  704  may have a structure similar to fulcrum  504  described above. For example, anchor  704  may be a vertical support or stanchion extending from first wall  104  into an internal volume within housing  102 . Like fulcrum  504 , anchor  704  may be a rigid support, i.e., having a higher stiffness than housing  102 . Unlike fulcrum  504 , however, anchor  704  may support cantilever  702  rather than lever  502 . Cantilever  702  may be flexible and have a stiffness less than the stiffness of housing  102  and/or anchor  704 . As such, a load applied to a free end of cantilever  702  may deflect cantilever  702  such that cantilever  702  acts as a spring. 
     First speaker module  310  may be mounted on cantilever  702  at first end  306 . Thus, when driven by audio signal  312 , voicecoil  210  of first speaker module  310  may move along first axis  314  in a first direction. Accordingly, sound  316  generated by first speaker module  310  may be directed along first axis  314  and outward through ports in housing  102 . The sound generation may be accompanied by a reactive force that is transmitted into cantilever  702 . Cantilever  702  may absorb energy from the reactive force and dissipate the energy to reduce parasitic force transmission into housing  102 , much as the gaskets described above reduce such parasitic force transmission. Furthermore, electronic device  100  may include gaskets, e.g., first gasket  340 , to absorb mechanical energy and to direct sound  316  from the speaker modules  200  within housing  102  outward into the surrounding environment. 
     Electronic device  100  may include several cantilevers  702  extending laterally within housing  102  from respective anchors  704 . For example, a second cantilever  702  may extend laterally from a second anchor  704  in an opposite direction of the first cantilever  702 . Second speaker module  320  may be mounted on the second cantilever  702 . For example, second speaker module  320  may be mounted at second end  308  of the second cantilever  702 . When driven by audio signal  312 , a respective voicecoil  210  of second speaker module  320  may move along second axis  322 . First speaker module  310  and second speaker module  320  may be acoustically in-phase and mechanically out-of-phase such that audio signal  312  drives their voicecoils  210  in opposite directions. Thus, when first speaker module  310  radiates sound  316  through first wall  104  of housing  102 , second speaker module  320  may radiate sound  316  through second wall  106  of housing  102 . A parasitic reactive force from second speaker module  320  may be transmitted into second cantilever  702 , and second cantilever  702  may absorb and dissipate energy from the reactive force. Thus, in addition to having offset reactive forces to reduce a net parasitic force, energy may be dissipated within cantilevers  702  rather than being transmitted into housing  102 . Accordingly, the rub and buzz problem may be mitigated. 
     Experiments have proven that the above-described embodiments reduce force transmission into housing  102 . For example, the embodiment described with respect to  FIG. 3  reduced force transmission into housing  102  by about 6 dB as compared to a typical in-phase speaker pair. Similarly, the embodiment described with respect to  FIG. 5  reduced force transmission into housing  102  by an additional 5-10 dB. Accordingly, it has been shown that a rigidly supported lateral link between laterally offset speaker modules driven acoustically in-phase and mechanically out-of-phase may reduce parasitic force transmission into a housing to reduce rub and buzz. 
     Referring to  FIG. 8 , a schematic view of an electronic device is shown in accordance with an embodiment. Electronic device  100  may have a processing system that includes the illustrated system architecture. Certain standard and well-known components which are not germane to the present invention are not shown. 
     Processing system may include an address/data bus  802  for communicating information, and one or more processors  804  coupled to bus  802  for processing information and instructions. Processing system may also include data storage features such as main memory  806  having computer usable volatile memory, e.g., random access memory (RAM), coupled to bus  802  for storing information and instructions for processor(s)  804 , static memory  808  having computer usable non-volatile memory, e.g., read only memory (ROM), coupled to bus  802  for storing static information and instructions for the processor(s)  804 , and a data storage device  810  (e.g., a magnetic or optical disk and disk drive) coupled to bus  802  for storing information and instructions. 
     Data storage device  810  may include a non-transitory machine-readable storage medium  812  storing one or more sets of instructions (e.g., software  813 ). Software  813  may include software applications, for example. Software  813  may also reside, completely or at least partially, within main memory  806 , static memory  808 , and/or within processor(s)  804  during execution thereof by processing system. More particularly, main memory  806 , static memory  808 , and processor(s)  804  may also constitute non-transitory machine-readable storage media. 
     Processing system of the present embodiment also includes input devices for receiving active or passive input. For example, an alphanumeric input device  814  may include alphanumeric and function keys coupled to bus  802  for communicating information and command selections to processor(s)  804 . Alphanumeric input device  814  may include input devices of various types, including keyboard devices, touchscreen devices, or voice activation input devices, to name a few types. Processing system may also include a cursor control  816  device, e.g., a mouse device, coupled to bus  802  for communicating user input information and command selections to processor(s)  804 . Such devices may be manual input device  110  as described above. Processing system may include a display device  818 , such as display  108  described above, which may be coupled to bus  802  for displaying information to an operator. 
     In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Metadata:
Filing Date: 20160706
Publication Date: 20181023
Grant Date: 20181023
Priority Date: 20160706
Inventors: Crosby, Justin D.
BOOTHE, DANIEL K.
FARAHANI, HOUTAN R.
SWEET, EDWARD T.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/403", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/2896", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/2819", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2896", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/403", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/2819", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/323", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2819", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2896", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/323", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 60892781