PATENT DOCUMENT

Publication Number: US-10271121-B2
Application Number: US-201715403095-A
Country: US
Kind Code: B2

Title: Shock mounted transducer assembly

Abstract:
An electronic device comprising having an enclosure with an enclosure wall separating a surrounding environment from an encased space. The enclosure wall includes a top portion having an acoustic channel extending from the encased space to the surrounding environment and a bottom portion. A microphone assembly module positioned within the encased space, and having a microphone acoustically coupled to a sound inlet port that is aligned with the acoustic channel and an air permeable water resistant membrane. A first support member is dimensioned to translatably couple the microphone assembly module to the top portion of the enclosure wall and translate the microphone assembly in response to a pressure change within the acoustic channel, and a second support member is dimensioned to translatably couple the microphone assembly module to the bottom portion of the enclosure wall.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall comprises a top portion having an acoustic channel extending from the encased space to the surrounding environment and a bottom portion; 
 a microphone assembly module positioned within the encased space, the microphone assembly module having a microphone acoustically coupled to a sound inlet port that is aligned with the acoustic channel and an air permeable water resistant membrane positioned between the sound inlet port and the acoustic channel; 
 a first support member dimensioned to translatably couple the microphone assembly module to the top portion of the enclosure wall such that the microphone assembly module is operable to translate in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel; and 
 a second support member dimensioned to translatably couple the microphone assembly module to the bottom portion of the enclosure wall, the second support member having a compliance sufficient to accommodate the translation of the microphone assembly module in response to the pressure change. 
 
     
     
       2. The device of  claim 1  wherein the microphone assembly module further comprises a flexible printed circuit board to which the microphone is mounted, and a stiffening layer formed between the flexible printed circuit board and the air permeable water resistant membrane, the stiffening layer comprising an opening aligned with the acoustic channel and the sound inlet port. 
     
     
       3. The device of  claim 1  wherein the microphone is a micro-electrical-mechanical system (MEMS) microphone. 
     
     
       4. The device of  claim 1  wherein the first support member is fixedly coupled to the microphone assembly module and translatably coupled to the acoustic channel. 
     
     
       5. The device of  claim 1  wherein the first support member comprises a base portion attached to the microphone assembly module and an extension portion extending from the base portion and into the acoustic channel, and wherein the extension portion is dimensioned to slide within the acoustic channel in response to the pressure change. 
     
     
       6. The device of  claim 1  wherein the first support member comprises a surface area sufficient to, in response to the pressure change, drive movement of the microphone assembly module coupled to the first support member. 
     
     
       7. The device of  claim 1  wherein the first support member comprises an extension portion that is sealed within the acoustic channel by an o-ring positioned between the extension portion and the acoustic channel. 
     
     
       8. The device of  claim 7  wherein the o-ring is overmolded to the extension portion. 
     
     
       9. The device of  claim 7  wherein the o-ring comprises a hydrophobic coating that reduces a friction between the o-ring and the acoustic channel. 
     
     
       10. The device of  claim 1  wherein the second support member comprises a foam material positioned between the microphone assembly module and the bottom portion. 
     
     
       11. The device of  claim 1  wherein the pressure change comprises a sudden pressure change to a pressure that is greater than a maximum pressure threshold of the air permeable water resistant membrane, and a translation of the microphone assembly module reduces a corresponding pressure on the air permeable water resistant membrane to below the maximum pressure threshold. 
     
     
       12. The device of  claim 1  further comprising an acoustic mesh positioned between the acoustic channel and the air permeable water resistant membrane, the acoustic mesh comprising a configuration suitable to reduce an impact of the pressure change on the air permeable water resistant membrane. 
     
     
       13. An electronic device comprising:
 an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall comprises a top portion having an acoustic channel that acoustically couples the encased space to the surrounding environment and a bottom portion; 
 a microphone assembly translatably positioned within the encased space, the microphone assembly having a microphone comprising a sound inlet port aligned with the acoustic channel and a protective membrane positioned over the sound inlet port; and 
 a support member dimensioned to translatably couple the microphone assembly to the enclosure wall and translate the microphone assembly in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel to reduce an impact of the pressure change on the protective membrane. 
 
     
     
       14. The device of  claim 13  wherein the protective membrane is an air permeable water resistant membrane. 
     
     
       15. The device of  claim 13  wherein the protective membrane comprises a maximum threshold pressure, and the impact of the pressure change on the protective membrane is reduced to below the maximum threshold pressure. 
     
     
       16. The device of  claim 13  wherein the support member comprises an extension portion positioned within the acoustic channel, and the extension portion comprises a top side having a surface area sufficient to receive a force corresponding to the pressure change and move the support member and microphone assembly toward the bottom portion of the enclosure to reduce the impact of the pressure change on the protective membrane. 
     
     
       17. The device of  claim 13  wherein the support member comprises an extension portion sealed within the acoustic channel, and the extension portion comprises an opening that acoustically couples the acoustic channel to the sound inlet port. 
     
     
       18. The device of  claim 13  wherein the support member comprises a compliant member positioned between the microphone assembly and the bottom portion of the enclosure wall, wherein the compliant member deforms in response to the pressure change. 
     
     
       19. An electronic device comprising:
 an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall comprises a top portion having an acoustic channel that acoustically couples the encased space to the surrounding environment and a bottom portion; and 
 a transducer assembly translatably positioned within the encased space by a support member, the support member is coupled to the transducer assembly and comprises an extension portion that extends from the transducer assembly into the acoustic channel, and the extension portion is configured to translate the transducer assembly in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel to reduce an impact of the pressure change on the transducer assembly. 
 
     
     
       20. The device of  claim 19  wherein the transducer assembly is a microphone assembly module comprising a micro-electrical-mechanical system (MEMS) microphone mounted to a printed circuit board, a sound inlet port to the MEMS microphone and an air permeable water resistant membrane positioned over the sound inlet port, and the support member translates the microphone assembly module to reduce a deflection of the air permeable water resistant membrane in response to the pressure change.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the earlier filing date of U.S. Provisional Patent Application No. 62/399,164, filed Sep. 23, 2016 and incorporated herein by reference. 
    
    
     FIELD 
     An embodiment of the invention is directed to a shock mounted transducer assembly, more specifically a microphone assembly that is movable within an enclosure in response to a pressure change so as to reduce an impact of the pressure change on the assembly components. Other embodiments are also described and claimed. 
     BACKGROUND 
     Cellular telephone handsets and smart phone handsets have within them a microphone that converts input sound pressure waves produced by the user speaking into the handset into an output electrical audio signal. The handset typically has a housing with an opening through which incoming sound pressure waves created by the user&#39;s voice can reach the microphone. This opening, however, can also allow for entry of short bursts of fluids such as gasses and liquids that cause rapid and short pressure changes within the system. If these rapid pressure changes reach the microphone and its associated components, they can cause damage to the various microphone components that are not designed to withstand such a force (e.g., membranes). 
     SUMMARY 
     An embodiment of the invention is directed to a transducer assembly having a transducer (e.g., a microphone assembly) that is soft mounted, or shock mounted, within an enclosure. In other words, the transducer is mounted such that it can move within the enclosure in response to, for example, a sudden pressure change or acoustic shock. Soft or shock mounting of the transducer provides several advantages. For example, the ability of the transducer to move within the enclosure may help to protect the assembly and its components from pressure changes caused by, for example, sudden impact events. In addition, it may smooth out transients due to rapid changes or oscillations in pressure. In the case of a microphone assembly, the microphone assembly may include, among other components, a microphone (e.g., a micro-electrical-mechanical system (MEMS) microphone) mounted to a flexible printed circuit (FPC) and a stiffener formed on the FPC to make it more rigid. In addition, in order to waterproof the microphone, an air permeable water resistant membrane may be placed over the opening to the microphone. The membrane may be designed to prevent water ingress when the microphone is placed under water and depending upon the pressure of the water, may deflect in response to the water pressure. A high pressure resulting in rapid deflections of the membrane may, however, be undesirable as this could cause damage to the membrane, for example, if the membrane repeatedly and abruptly contacts the underlying stiffener. Thus, the assembly may further include one or more support structures that allow for the microphone assembly to move or translate in response to a sudden or abrupt pressure change (e.g., such as that caused by diving into water) and reduce an impact of the pressure change on the membrane. 
     Representatively, in one embodiment, the invention includes an electronic device having an enclosure formed by an enclosure wall that separates a surrounding environment from an encased space. The enclosure wall may include a top portion having an acoustic channel extending from the encased space to the surrounding environment and a bottom portion. In one embodiment, a microphone assembly module may be positioned within the encased space. The microphone assembly module may have a microphone acoustically coupled to a sound inlet port that is aligned with the acoustic channel and an air permeable water resistant membrane positioned between the sound inlet port and the acoustic channel. The device may further include a first support member dimensioned to translatably couple the microphone assembly module to the top portion of the enclosure wall such that the microphone assembly module is operable to translate in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel. In addition, the device may include a second support member dimensioned to translatably couple the microphone assembly module to the bottom portion of the enclosure wall. The second support member may have a compliance sufficient to accommodate the translation of the microphone assembly module in response to the pressure change. In other words, the support member is compliant or resilient enough to deform and allow the microphone assembly module to compress it in response to the pressure change to reduce the impact pressure, in contrast to a stronger material, which does not compress unless subjected to a much higher force or pressure than the pressure change. In some embodiments, the microphone assembly module further includes a flexible printed circuit board to which the microphone is mounted, and a stiffening layer formed between the flexible printed circuit board and the air permeable water resistant membrane. The stiffening layer may include an opening aligned with the acoustic channel and the sound inlet port. The microphone may be a micro-electrical-mechanical system (MEMS) microphone. The first support member may be fixedly coupled to the microphone assembly module and translatably coupled to the acoustic channel. In other words, the first support member and the microphone assembly module may move together along the acoustic channel, which is stationary. For example, the first support member may include a base portion attached to the microphone assembly module and an extension portion extending from the base portion and into the acoustic channel. In some cases, the extension portion is dimensioned to slide within the acoustic channel in response to the pressure change. The first support member may include a surface area sufficient to, in response to the pressure change, drive movement of the microphone assembly module coupled to the first support member. For example, the first support member may include a surface area large enough to allow it to extend into the acoustic channel and within the pathway of the input pressure so that the resulting pressure on the first support member and moves the support member, and in some cases, deflects the input pressure away from the membrane. 
     In some embodiments, the first support member may include an extension member or portion that is sealed within the acoustic channel by an o-ring positioned between the extension member and the acoustic channel. The o-ring may be overmolded to the extension member. The o-ring may further include a hydrophobic coating that reduces a friction between the o-ring and the acoustic channel. In some embodiments, the second support member includes a foam material positioned between the microphone assembly module and the bottom portion. The second support member may include a compliance sufficient to reduce an impact of the pressure change on the air permeable water resistant membrane; for example, a compliance or resilience such that it compresses in response to the pressure change, and allows the microphone assembly to translate within the enclosure in a direction away from the input pressure. In some embodiments, the pressure change is a sudden pressure change to a pressure that is greater than a maximum pressure threshold of the air permeable water resistant membrane, and a translation of the microphone assembly module reduces a corresponding pressure on the air permeable water resistant membrane to below the maximum pressure threshold. The device may further include an acoustic mesh positioned between the acoustic channel and the air permeable water resistant membrane. The acoustic mesh may include a configuration suitable to reduce an impact of the pressure change on the air permeable water resistant membrane. 
     In another embodiment, the invention is directed to an electronic device having an enclosure made up of an enclosure wall separating a surrounding environment from an encased space. The enclosure wall may include a top portion having an acoustic channel that acoustically couples the encased space to the surrounding environment and a bottom portion. The device may further include a microphone assembly translatably positioned within the encased space. The microphone assembly may include a microphone acoustically coupled to a sound inlet port aligned with the acoustic channel and a protective membrane positioned over the sound inlet port. In addition, a support member may be dimensioned to translatably couple the microphone assembly to the enclosure wall and translate the microphone assembly in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel to reduce an impact of the pressure change on the protective membrane. The protective membrane may be an air permeable water resistant membrane. The protective membrane may have a maximum threshold pressure, and the impact of the pressure change on the protective membrane may be reduced to below the maximum threshold pressure. In some embodiments, the support member may include an extension member or portion positioned within the acoustic channel, and the extension member includes a top side having a surface area sufficient to receive a force corresponding to the pressure change and move the support member and microphone assembly toward the bottom portion of the enclosure to reduce the impact of the pressure change on the protective membrane. For example, the support member may include an extension member sealed within the acoustic channel, and the extension member may include an opening that acoustically couples the acoustic channel to the sound inlet port. In other embodiments, the support member may include a compliant member positioned between the microphone assembly and the bottom portion of the enclosure wall, and the compliant member may deform in response to the pressure change. 
     In another embodiment, the invention is directed to an electronic device including an enclosure having an enclosure wall separating a surrounding environment from an encased space. The enclosure wall may include a top portion having an acoustic channel that acoustically couples the encased space to the surrounding environment and a bottom portion. A transducer assembly may be translatably positioned within the encased space by a support member, and the support member may be dimensioned to translate the transducer assembly in a direction parallel to an axis of the acoustic channel in response to a pressure change within the acoustic channel to reduce an impact of the pressure change on the transducer assembly. For example, the transducer assembly may include a microphone assembly module including a micro-electrical-mechanical system (MEMS) microphone mounted to a printed circuit board, a sound inlet port to the MEMS microphone and an air permeable water resistant membrane positioned over the sound inlet port. The support member may translate the microphone assembly module to reduce a deflection of the air permeable water resistant membrane in response to the pressure change. 
     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 
       The embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and they mean at least one. 
         FIG. 1  illustrates a cross-sectional side view of one embodiment of a transducer assembly. 
         FIG. 2  illustrates a cross-sectional side view of the transducer assembly of  FIG. 1  in a resting configuration. 
         FIG. 3  illustrates a cross-sectional side view of the transducer assembly of  FIG. 1  in a translated configuration. 
         FIG. 4  illustrates a line graph of an input pulse pressure impact on the transducer assembly of  FIG. 3 . 
         FIG. 5  illustrates a schematic diagram of embodiments of a portable electronic device. 
         FIG. 6  illustrates a schematic diagram of one embodiment of a portable electronic device. 
         FIG. 7  illustrates a schematic diagram of one embodiment of circuitry of a portable electronic device within which the transducer assembly of  FIG. 1  is integrated. 
     
    
    
     DETAILED DESCRIPTION 
     In this section we shall explain several preferred embodiments of this invention with reference to the appended drawings. Whenever the shapes, relative positions and other aspects of the parts described in the embodiments are not clearly defined, the scope of the invention is not limited only to the parts shown, which are meant merely for the purpose of illustration. Also, while numerous details are set forth, it is understood that some embodiments of the invention may be practiced without these details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this description. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, and the like may be used herein for ease of description to describe one element&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising” specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. 
     The terms “or” and “and/or” as used herein are to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” or “A, B and/or C” mean “any of the following: A; B; C; A and B; A and C; B and C; A, B and C.” An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive. 
       FIG. 1  illustrates a cross-sectional side view of one embodiment of transducer assembly. In some embodiments, transducer assembly  100  may include a microphone assembly  102  positioned within an enclosure  104 . The enclosure  104  may be an outer enclosure or housing for the electronic device within which microphone assembly  102  is integrated (e.g., a smart phone case) or an inner casing or module which encloses only the microphone assembly  102  and is then mounted within the outer casing. In addition, while transducer assembly  100  is described as including a microphone assembly  102 , it is contemplated that transducer assembly  100  may include other types of transducers capable of converting one form of energy to another (e.g., a speaker, an ambient pressure sensor, position sensor, or the like). 
     Referring now to enclosure  104 , enclosure  104  may include an enclosure wall  106  that separates a surrounding environment from an encased space  108  formed within enclosure  104 . The encased space  108  may be of a sufficient volume and/or size to accommodate microphone assembly  102  and any other associated components. The enclosure wall  106  may include a top portion  110  and a bottom portion  112  which are positioned on opposing sides of encased space  108 . An acoustic channel  114  may be formed through top portion  110 . Acoustic channel  114  may extend from encased space  108  to the surrounding environment. Thus, acoustic channel  114  may provide a passageway for sound pressure waves or a fluid pressure input in general (e.g., air or water) to reach encased space  108  within enclosure  104 . For example, a pressure input  116  from the surrounding environment may travel along channel axis  118  of acoustic channel  114  to microphone assembly  102  within encased space  108 . Acoustic channel  114  may therefore be considered to fluidly or acoustically couple encased space  108 , and the components therein (e.g., microphone assembly  102 ), with the surrounding environment. It should be noted that the surrounding environment may, in some embodiments, be a completely open fluid space, or in other embodiments, a substantially closed space (e.g., a space enclosed between enclosure  104  and an outer casing). 
     Acoustic channel  114  may further include a track or recessed region  120  that can be used to help guide the movement (e.g., translation) of microphone assembly  102  within encased space  108 . In particular, in some cases where pressure input  116  is a sudden or pulse pressure, it may exert a force or pressure on microphone assembly  102  and its associated components that can compromise their operation, as previously discussed. In order to reduce the impact, microphone assembly  102  can translate as shown by arrows  124  within encased space  108  when, for example, pressure input  116  is above a certain threshold. In other words, microphone assembly  102  can translate in a direction parallel to channel axis  118  (e.g., a z-direction  122 ). For example, where the pressure input  116  is in a downward direction as shown, microphone assembly  102  may move in a downward direction (e.g., away from a direction of the force and toward enclosure bottom portion  112 ) and redistribute or spread out the impact (e.g., force) along a larger surface area of the microphone assembly  102  thus reducing the impact on any particular component within microphone assembly  102 . 
     Referring in more detail now to microphone assembly  102 , microphone assembly  102  is made up of a stack-up of various microphone associated components. For example, microphone assembly  102  may include a microphone  136  positioned within a housing or casing  140 , which is mounted to a printed circuit  144  including microphone circuitry for operating microphone  136 . Microphone  136  may, for example, be a micro-electrical-mechanical system (MEMS) microphone that is made up of a pressure-sensitive diaphragm etched into a silicon wafer using MEMS processing techniques and mounted to printed circuit  144 . It should be understood, however, that although a MEMS microphone is disclosed, other types of microphones or transducers (e.g., speaker, ambient pressure sensor, or the like) that could benefit from a reduced impact pressure could be used instead of a microphone. In addition, printed circuit  144  may, in some embodiments, be a flexible printed circuit (FPC) that includes a flexible substrate (e.g., a flexible plastic or polyester substrate) with circuitry printed thereon. An acoustic input port  142  to allow for sound input to microphone  136  may be formed within a portion of printed circuit  144  over microphone  136 . 
     In addition, microphone assembly  102  may include a protective membrane  156  positioned over acoustic input port  142 . Protective membrane  156  may be an air permeable water resistant membrane through which sound can pass to microphone  136  but which prevents water ingress into microphone  136 . In addition, protective membrane  156  may be compliant, or otherwise have elastic deformation properties, such that it can flex or deflect and then return to its original position in response to a change in pressure input  116 . For example, protective membrane  156  may deflect in response to a gradual or constant water pressure increase (e.g., such as when diving) and then return to its original position once the pressure is removed or otherwise reduced. Representatively, in one embodiment, protective membrane  156  may be a polytetrafluoroethylene (PTFE) membrane. Protective membrane  156  may, however, be made of any material suitable for forming an air permeable water resistant membrane. 
     In addition, a stiffening layer  150  may be positioned between protective membrane  156  and printed circuit  144  to provide structural stability to printed circuit  144  and/or protective membrane  156 . Stiffening layer  150  may include an opening  152 , which is aligned with acoustic channel  114  and acoustic input port  142  so that sound can pass through protective membrane  156  and stiffening layer  150  to microphone  136 . Stiffening layer  150  may be made of any material suitable for providing structural stiffness or reinforcement to, for example, flexible printed circuit  144  (e.g., steel). 
     Each of the microphone assembly components may be assembled as a stack-up including each component attached together using, for example, layers of an adhesive material. Representatively, in one embodiment, microphone  136  and casing  140  may be mounted or otherwise attached to a bottom side of printed circuit  144  (a side facing bottom portion  112 ) using an adhesive or soldering, depending upon the desired connection. A bottom side of stiffening layer  150  may be attached to the top side of printed circuit  144  by adhesive layer  148 . Protective membrane  156  may then be attached to a top side of stiffening layer  150  using adhesive layer  154  to complete the microphone assembly stack-up. Adhesive layers  148  and  154  may be, for example, layers of pressure-sensitive adhesive (PSA) (e.g., an elastomer based compound) that forms a bond when pressure is applied. 
     The microphone assembly  102  may then be translatably mounted within encased space  108  using support member  126  and support member  160 . Representatively, support member  126  may be a first or top support member that is fixedly attached to a top side of microphone assembly  102  while support member  160  may be considered a second or bottom support member which is fixedly attached to a bottom side of microphone assembly  102 . In this aspect, support member  126  is positioned between microphone assembly  102  and top portion  110  of enclosure wall  106 . Support member  160  is positioned between microphone assembly  102  and bottom portion  112  of enclosure wall  106 . 
     Referring in more detail now to support member  126 , support member  126  may be dimensioned to attach or otherwise suspend microphone assembly  102  from top portion  110  of enclosure wall  106 . Representatively, support member  126  may include a base portion  130  and an extension portion  128  extending from base portion  130 . Base portion  130  may be a substantially horizontal or lateral member that is fixedly attached to the top side of microphone assembly  102 . More specifically, base portion  130  may have a bottom side that is attached to a portion of the top side of protective membrane  156  by adhesive layer  158  (e.g., PSA adhesive layer). Extension portion  128  may be a vertically extending portion that is substantially perpendicular to base portion  130  and positioned within acoustic channel  114 . Extension portion  128  may include a top end  132  and an opening  168  extending from top end  132  through base portion  130  so that sound entering acoustic channel  114  can pass through extension portion  128  to microphone assembly  102 . For example, opening  168  may be aligned with, and in some cases positioned concentrically inward to, acoustic channel  114  and positioned over protective membrane  156 . 
     As previously discussed, in some cases (e.g., a sudden pressure input), it may be desirable to reduce the impact of this pressure change within acoustic channel  114  on protective membrane  156 . Said another way, it is desirable to reduce a deflection of the protective membrane  156  in response to the pressure change. The top end  132  of extension portion  128  may therefore have a surface area (SA) dimensioned to help redistribute pressure input  116  away from protective membrane  156  and allow support member  126  (and associated microphone assembly  102  including protective membrane  156 ) to move (translate) in a direction away from the direction of pressure input. In this aspect, the impact pressure or force of pressure input  116  is redistributed along the entire assembly, and therefore only a portion of the pressure input  116  impacts protective membrane  156 , thereby reducing membrane deflection. For example, in one embodiment, the surface area (SA) of top end  132  may be greater than a surface area of protective membrane  156  exposed to pressure input  116  (e.g., area exposed through opening  168 ). Said another way, top end  132  may have a surface area (SA) such that it extends into, or partially occludes, acoustic channel  114 . In this aspect, a portion of pressure input  116  through acoustic channel  114  is deflected or redirected away from protective membrane  156  and pushes against top end  132  of support member  126 , which in turn, pushes support member  126  (and microphone assembly  102 ) down toward the bottom portion  112  of enclosure  104 . As a result, the impact pressure from pressure input  116  that actually reaches protective membrane  156  is reduced to, for example, a level below the maximum threshold pressure of protective membrane  156 . 
     To further facilitate the sealing and sliding (or translation) of extension portion  128  within acoustic channel  114  as indicated by arrows  124 , acoustic channel  114  may include a recessed region  120  dimensioned to receive an o-ring  134  positioned around extension portion  128 . In particular, recessed region  120  may be an annularly shaped recess formed within the inner surface of acoustic channel  114 . Recessed region  120  may have a height sufficient to accommodate a sliding movement of o-ring  134  therein and overall width to allow for sealing between o-ring  134  and the inner surface of acoustic channel  114 . O-ring  134  may be, for example, an elastomeric loop positioned around the outer surface of extension portion  128 , and in some cases within a channel around the outer surface of extension portion  128 . For example, in one embodiment, o-ring  134  is fixedly attached to extension portion  128  such that it does not move with respect to extension portion  128 , rather it translates along with extension portion  128  within acoustic channel  114 . Representatively, o-ring  134  may be formed by overmolding, or injection molding, an elastomeric ring within an annularly shaped channel formed around extension portion  128 . It is also contemplated that in some embodiments, o-ring  134 , or another similarly shaped gasket structure may be molded, or otherwise mounted, along the inner surface of acoustic channel  114 . In such embodiments, o-ring  134  is therefore fixed to acoustic channel  114  and does not move as extension portion  128  slides within acoustic channel  114 . In either case, it is important that o-ring  134  also provide a seal between extension portion  128  and acoustic channel  114  such that, for example, a fluid such as water or air is prevented from passing around extension portion  128  and into encased space  108 . 
     In addition, in some embodiments, it may be desirable to reduce a friction between o-ring  134  and acoustic channel  114  such that extension portion  128  can slide or translate within acoustic channel  114  more easily. In such embodiments, o-ring  134  may include a surface finish or coating which reduces a friction or surface energy between o-ring  134  and the surface of acoustic channel  114 , while still allowing for sealing between the two. For example, o-ring  134  may be coated with a hydrophobic coating (e.g., a thin polytetrafluoroethylene (PTFE) fluoropolymer coating). 
     Referring in more detail now to bottom support member  160 , bottom support member  160  may further be configured to facilitate the translation of microphone assembly  102  and reduce a pressure impact on protective membrane  156 . Representatively, bottom support member  160  may be positioned below microphone assembly  102  and help to absorb the pressure shock associated with a sudden or pulse pressure input  116 . This, in turn, reduces the impact of this pressure on protective membrane  156 , and/or microphone assembly  102  in general. In this aspect, bottom support member  160  may be a compliant, elastic or deformable structure that is capable of deforming or compressing in response to a pressure input, and then returning to its original configuration once the pressure is removed or reduced as illustrated by arrows  162 . Representatively, bottom support member  160  may be formed of a compliant or resilient foam material that is of a compliance or resilience sufficient to deform when microphone assembly  102  is pressed toward the bottom portion  112  of enclosure  104  by pressure input  116 . As previously discussed, the pressure input  116  may be a sudden or pulse pressure input which is greater than a maximum threshold pressure of protective membrane  156 , thus bottom support member  160  may have a compliance or resilience sufficient to allow it to deform in response to a pressure input  116  above the maximum threshold pressure of protective membrane  156 . In addition, bottom support member  160  should have a compliance or resilience sufficient to allow it to return back to its original configuration once the pressure is removed or otherwise reduced below the threshold pressure. In this aspect, top support member  126  and bottom support member  160  work together to facilitate translation of microphone assembly  102  in the direction illustrated by arrows  124 ,  162  (e.g., a z-direction  122  parallel to the axis  118  of acoustic channel  114 ) in response to an undesirable pressure change (e.g., pulse pressure) within acoustic channel  114  and reduce an impact pressure on protective membrane  156 . 
     In one embodiment, bottom support member  160  may, for example, be a ring of foam that is positioned outward of microphone casing  140  and attached along a top side to printed circuit  144  by adhesive layer  146 . Bottom support member  160  may further include a bottom side attached (e.g., by another PSA layer) to a bracket  164  mounted to bottom portion  112  of enclosure  104 . In this aspect, bottom support member  160  may be considered fixedly attached to both microphone assembly  102  and enclosure  104 , but because of its compliance can deform in a direction of arrows  162  (e.g., a z-direction  122 ) and facilitate translation of microphone assembly  102 . In other embodiments, bottom support member  160  may include multiple layers of foam having different compliances (e.g., a high compliance foam and a low compliance foam), a spring, or be composed of any other type of structure or material suitable for facilitating translation of microphone assembly  102 . It is noted, however, that the overall compliance or resilience of bottom support member  160  should be greater than that of a foam or other compliant material used for the purpose of absorbing acoustic vibrations associated with microphone assembly  102  and which would be too strong to allow for translation of microphone assembly  102  as discussed herein. 
     In addition, in some embodiments, transducer assembly  100  may include an acoustic mesh  166  to further reduce an impact of pressure input  116  on protective membrane  156 . Representatively, acoustic mesh  166  may be positioned within opening  168  of support member  126  and within the pathway between pressure input  116  and protective membrane  156 . Pressure input  116  must therefore travel through acoustic mesh  166  before reaching protective membrane  156 . Acoustic mesh  166  may have a density, pore size, or other property, sufficient to slow, deflect, disperse or absorb some of pressure input  116  such that the corresponding impact force or pressure which reaches protective membrane  156  is less than the total input pressure entering acoustic channel  114 . For example, in one embodiment, acoustic mesh  166  is made up of strands of a material (e.g., a metal, fiber or other flexible material) that are interconnected and form holes or pores dispersed throughout the mesh. The holes or pores may be of a size sufficient to allow for air passage and achieve a mesh with the desired acoustic properties yet deflect, disperse or otherwise slow down the passage of other fluids, for example, water. In this aspect, an impact of any portion of pressure input  116  not already deflected or dispersed by support member  126  and the movement of microphone assembly  102 , is further reduced by acoustic mesh  166 . Acoustic mesh  166  may, in one embodiment, be positioned within opening  168  of extension portion  128  by mounting it to the sidewall of opening  168 . 
     The translation of microphone assembly  102  with respect to enclosure  104  will now be described in more detail in reference to  FIG. 2  and  FIG. 3 . In particular,  FIG. 2  and  FIG. 3  illustrate the transducer assembly  100  of  FIG. 1 , except that in  FIG. 2  microphone assembly  102  is shown in a resting configuration (e.g., low input pressure) and in  FIG. 3  microphone assembly  102  is shown in a translated configuration (e.g. pulse pressure). Representatively, in  FIG. 2 , pressure input  116  is normal, or lower than a maximum threshold pressure of the protective membrane  156  of microphone assembly  102 . Thus, support member  126  and microphone assembly  102  are not pushed down toward bottom portion  112  of enclosure  104  under the pressure. This is illustrated by the top end  132  of support member  126  being near the top edge  202  of recessed region  120  of acoustic channel  114  and bottom support member  160  being in its non-compressed state (e.g., not compressed in a direction of arrows  206 ). It should be understood that a “normal” pressure input  116  would be, for example, that which would be produced by a user speaking into the device, or an otherwise constant pressure that is typically input to a microphone. A sudden, rapid, pulse or otherwise undesirable input pressure would be one not associated with typical user interactions, for example, a sudden pressure change or increase that could occur during diving or dropping of the device within which transducer assembly  100  is implemented. 
     When the pressure input  116  within acoustic channel  114  changes, for example suddenly increases, as illustrated in  FIG. 3  by the presence of multiple input pressure arrows, the pressure pushes support member  126 , microphone assembly  102  and support member  160  down toward bottom portion  112  of enclosure  104 . In particular, pressure input  116  applies a pressure to the top end  132  of support member  126 , which as previously discussed has relatively large surface area (SA) which helps to disperse the pressure away from opening  168  to microphone assembly  102  and pushes support member  126  in a downward direction as illustrated by arrows  224  (e.g., toward bottom portion  112 ). Extension portion  128  and o-ring  134  are therefore near the bottom edge  204  of recessed region  120  and microphone assembly  102  is positioned closer to bottom portion  112  of enclosure  104 . In addition, bottom support member  160  compresses and absorbs some of the pressure input and/or movement of microphone assembly  102 . In other words, bottom support member  160  can act as a shock absorber for the entire assembly. Thus, the resulting impact force or pressure  216  on microphone assembly  102 , and more specifically the protective membrane  156  as shown in  FIG. 1 , is reduced. For example, pressure input  116  may be reduced to an impact pressure  216  that is below a maximum pressure threshold of the protective membrane  156  as illustrated by  FIG. 4 . 
       FIG. 4  is a line graph showing a reduced pressure impact that can be achieved by transducer assembly  100 . Representatively, the graph shows an x-axis representing time and the y-axis representing pressure. The maximum threshold pressure of a protective membrane associated with microphone assembly  102  (e.g., protective membrane  156  of  FIG. 1 ) is illustrated by dashed line  406 . The maximum threshold pressure is the maximum pressure that the protective membrane has been designed to withstand. A sudden or pulse pressure (e.g., pressure input  116 ) is illustrated by waveform  408 , which shows a sudden spike in input pressure above the maximum threshold pressure  406  of the protective membrane. Because the pulse pressure is sudden and above the pressure limit of the membrane, it could potentially compromise the membrane structure and/or operation. The translation of the microphone assembly  102  as previously discussed, however, reduces the impact pressure to below the threshold pressure as illustrated by waveform  410 . Thus, the impact pressure on microphone assembly  102 , and more specifically the protective membrane, is within a range that will not negatively impact membrane operation. 
       FIG. 5  illustrates one embodiment of a simplified schematic view of embodiments of electronic devices in which a transducer assembly, such as that described herein, may be implemented. As seen in  FIG. 5 , the transducer may be integrated within a consumer electronic device  502  such as a smart phone with which a user can conduct a call with a far-end user of a communications device  504  over a wireless communications network; in another example, the transducer may be integrated within the housing of a portable timepiece. These are just two examples of where the transducer described herein may be used, it is contemplated, however, that the transducer may be used with any type of electronic device in which a transducer, for example, microphone, loudspeaker, receiver or sensor, is desired, for example, a tablet computer, a computing device or other display device. 
       FIG. 6  illustrates a block diagram of one embodiment of an electronic device within which the previously discussed transducer assembly may be implemented. As shown in  FIG. 6 , device  600  may include storage  602 . Storage  602  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory), volatile memory (e.g., battery-based static or dynamic random-access-memory), etc. 
     Processing circuitry  604  may be used to control the operation of device  600 . Processing circuitry  604  may be based on a processor such as a microprocessor and other suitable integrated circuits. With one suitable arrangement, processing circuitry  604  and storage  602  are used to run software on device  600 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. Processing circuitry  604  and storage  602  may be used in implementing suitable communications protocols. Communications protocols that may be implemented using processing circuitry  604  and storage  602  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3G or 4G communications services (e.g., using wide band code division multiple access techniques), 2G cellular telephone communications protocols, etc. 
     To minimize power consumption, processing circuitry  604  may include power management circuitry to implement power management functions. For example, processing circuitry  604  may be used to adjust the gain settings of amplifiers (e.g., radio-frequency power amplifier circuitry) on device  600 . Processing circuitry  604  may also be used to adjust the power supply voltages that are provided to portions of the circuitry on device  600 . For example, higher direct-current (DC) power supply voltages may be supplied to active circuits and lower DC power supply voltages may be supplied to circuits that are less active or that are inactive. If desired, processing circuitry  604  may be used to implement a control scheme in which the power amplifier circuitry is adjusted to accommodate transmission power level requests received from a wireless network. 
     Input-output devices  606  may be used to allow data to be supplied to device  600  and to allow data to be provided from device  600  to external devices. Display screens, microphone acoustic ports, speaker acoustic ports, and docking ports are examples of input-output devices  606 . For example, input-output devices  606  can include user input devices  608  such as buttons, touch screens, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, etc. A user can control the operation of device  600  by supplying commands through user input devices  608 . Display and audio devices  610  may include liquid-crystal display (LCD) screens or other screens, light-emitting diodes (LEDs), and other components that present visual information and status data. Display and audio devices  610  may also include audio equipment such as speakers and other devices for creating sound. Display and audio devices  610  may contain audio-video interface equipment such as jacks and other connectors for external headphones and monitors. 
     Wireless communications devices  612  may include communications circuitry such as radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, passive RF components, antennas, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). Representatively, in the case of a microphone acoustic port as shown in  FIG. 5 , transducer assembly  100  may be associated with the port and be in communication with an RF antenna for transmission of signals from the transducer to a far end user. Such a configuration is illustrated in more detail in  FIG. 7 . 
     For example,  FIG. 7  illustrates an embodiment of a device in which transducer assembly  100  (including microphone assembly  102 ) may be in communication with an audio processor  704  through path  702 . Path  702  may include wired and wireless paths. Signals from transducer assembly  100  may be transmitted through uplink audio signal path  714  to radio  708 . Radio  708  may transmit the signals via downlink audio signal path  716  to audio processor  706 , which is in communication with a far end user device  712  through path  720 . Alternatively, radio  708  may transmit the signals to RF antenna  710  through path  718 . Audio processor  704  may also be in communication with local storage  722 , a media player/recorder application  724  or other telephony applications  726  on the device, through path  732 , for local storage and/or recording of the audio signals as desired. Processor  728  may further be in communication with these local devices via path  734  and also display  730  via path  738  to facilitate processing and display of information corresponding to the audio signals to the user. Display  730  may also be in direction communication with local storage  722  and applications  726  via path  736  as illustrated. 
     Returning to  FIG. 6 , device  600  can communicate with external devices such as accessories  614 , computing equipment  616 , and wireless network  618  as shown by paths  620  and  622 . Paths  620  may include wired and wireless paths. Path  622  may be a wireless path. Accessories  614  may include headphones (e.g., a wireless cellular headset or audio headphones) and audio-video equipment (e.g., wireless speakers, a game controller, or other equipment that receives and plays audio and video content), a peripheral such as a wireless printer or camera, etc. 
     Computing equipment  616  may be any suitable computer. With one suitable arrangement, computing equipment  616  is a computer that has an associated wireless access point (router) or an internal or external wireless card that establishes a wireless connection with device  700 . The computer may be a server (e.g., an internet server), a local area network computer with or without internet access, a user&#39;s own personal computer, a peer device (e.g., another portable electronic device  600 ), or any other suitable computing equipment. 
     Wireless network  618  may include any suitable network equipment, such as cellular telephone base stations, cellular towers, wireless data networks, computers associated with wireless networks, etc. For example, wireless network  618  may include network management equipment that monitors the wireless signal strength of the wireless handsets (cellular telephones, handheld computing devices, etc.) that are in communication with network  618 . 
     While certain embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that the invention is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. For example, while the transducer assembly is disclosed as having a microphone assembly translatably coupled to the enclosure, it is contemplated that any type of transducer that could benefit from being movable within an enclosure as discussed could be used instead of a microphone, for example, a speaker or an ambient pressure sensor. Still further, although portable electronic devices such as mobile communications devices or portable timepieces are described herein, the transducer assembly may be implemented within a tablet computer, personal computer, laptop computer, notebook computer and the like. The description is thus to be regarded as illustrative instead of limiting.

Metadata:
Filing Date: 20170110
Publication Date: 20190423
Grant Date: 20190423
Priority Date: 20160923
Inventors: EVANS, NEAL D.
LIPPERT, Jesse A.
VITT, Nikolas T.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R2201/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/086", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/06", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/06", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/086", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2201/003", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 61685963