PATENT DOCUMENT

Publication Number: US-10148800-B1
Application Number: US-201715720709-A
Country: US
Kind Code: B1

Title: Acoustic compensation chamber for a remotely located audio device

Abstract:
An electronic device includes an internal microphone that is located remotely from a microphone aperture formed in the enclosure of the electronic device. An acoustic chamber is formed within the electronic device to couple the microphone to the microphone aperture. The acoustic chamber is designed with a particular length to volume ratio that amplifies a particular range of frequencies such that the microphone maintains equal sensitivity to a desired frequency band.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an enclosure including a wall, the wall having an interior surface opposite an exterior surface and a first opening formed through the wall; 
 a plate attached to the interior surface such that an acoustic chamber is defined between the plate and the interior surface; 
 a second opening formed through the plate; and 
 an acoustic device attached to the plate and aligned with the second opening such that the acoustic device is acoustically coupled to the first opening via the acoustic chamber and the second opening; 
 wherein the acoustic chamber has a first region proximate the first opening and a second region proximate the second opening, and wherein a first volume of the first region is larger than a second volume of the second region. 
 
     
     
       2. The electronic device of  claim 1  wherein the plate is attached to the interior surface with an adhesive layer. 
     
     
       3. The electronic device of  claim 2  wherein the adhesive layer is electrically conductive. 
     
     
       4. The electronic device of  claim 1  wherein a depth of the acoustic chamber is less than a thickness of the acoustic device. 
     
     
       5. The electronic device of  claim 1  wherein a recess is formed in the wall and the plate is positioned over the recess. 
     
     
       6. The electronic device of  claim 5  wherein a depth of the recess and a thickness of an adhesive layer positioned between the plate and the wall define a depth of the acoustic chamber. 
     
     
       7. The electronic device of  claim 5  wherein a protrusion is positioned in the recess and protrudes from a bottom surface of the recess towards the plate. 
     
     
       8. The electronic device of  claim 1  wherein a first area of the first region is larger than a second area of the second region. 
     
     
       9. The electronic device of  claim 1  wherein a center of the first opening is separated from a center of the second opening by a distance greater than 1 millimeter. 
     
     
       10. The electronic device of  claim 1  further comprising a flexible circuit disposed between the acoustic device and the plate, wherein the flexible circuit electrically couples the acoustic device to circuitry within the electronic device. 
     
     
       11. The electronic device of  claim 10  wherein the flexible circuit includes a plurality of perforations in a region that aligns with the second opening. 
     
     
       12. The electronic device of  claim 1  wherein the acoustic device is a microphone. 
     
     
       13. The electronic device of  claim 1  wherein the acoustic device is a speaker. 
     
     
       14. An electronic device comprising:
 an enclosure including a front wall positioned opposite a rear wall having an interior surface opposite an exterior surface; 
 a first opening formed through the rear wall; 
 a recess formed in the rear wall, the recess extending from the interior surface to a second surface; 
 a plate positioned over the recess and attached to the interior surface with an adhesive layer such that an acoustic chamber is defined between the plate and the interior surface; 
 a second opening formed through the plate; and 
 an acoustic device attached to the plate and aligned with the second opening such that the acoustic device is acoustically coupled to the first opening via the acoustic chamber and the second opening; 
 wherein a volume of the acoustic chamber changes along a length of the acoustic chamber. 
 
     
     
       15. The electronic device of  claim 14  wherein the adhesive layer is electrically conductive. 
     
     
       16. The electronic device of  claim 14  wherein a depth of the acoustic chamber is less than a thickness of the acoustic device. 
     
     
       17. The electronic device of  claim 14  wherein the acoustic device is a microphone. 
     
     
       18. The electronic device of  claim 14  wherein the acoustic device is a speaker. 
     
     
       19. The electronic device of  claim 14  further comprising a camera module positioned within the enclosure and aligned with the plate. 
     
     
       20. The electronic device of  claim 19  further comprising a compressible conductive interface material positioned between the camera module and the plate.

Description:
BACKGROUND 
     Currently there are a wide variety of electronic devices that include one or more cameras and microphones that can be used to record video images and/or audio. As electronic devices become smaller and more aesthetically appealing, the location of the camera aperture and the microphone aperture on the exterior of the electronic device may become important factors. Further, as electronic devices become more compact, the available room within the electronic device for electronic components such as a camera module and a microphone is reduced so it may not be possible to place an electronic component directly adjacent to its corresponding aperture. 
     New electronic devices may require new features or new methods of implementing internal electronic components to fit them within the allowable space and couple them to their respective apertures. 
     SUMMARY 
     Some embodiments of the present disclosure relate to an internal microphone for an electronic device that is positioned remotely from a microphone aperture that is formed in the enclosure. Some embodiments include an acoustic chamber that couples the microphone to the acoustic aperture and that is configured to compensate for attenuation of a range of frequencies that can occur due to the remote location of the microphone from its corresponding aperture. The acoustic chamber can have a particular length to volume ratio that amplifies a particular range of frequencies such that the microphone maintains equal sensitivity to a desired frequency band of interest. In further embodiments the acoustic chamber can be used with a speaker, instead of a microphone, and the chamber can compensate for a particular range of frequencies that may be attenuated due to the remote location of the speaker from its corresponding aperture. 
     In some embodiments the acoustic chamber can be formed between an internal surface of the enclosure of the device and a plate that is secured to the internal surface with an adhesive. The internal surface of the enclosure can include a recess to increase a depth of the acoustic chamber. In some embodiments the adhesive can be electrically conductive and the plate can function as a ground plane for adjacent electronic components, such as a camera module. 
     In some embodiments an electronic device comprises an enclosure including a wall, the wall having an interior surface opposite an exterior surface and a first opening formed through the wall. A plate is attached to the interior surface such that an acoustic chamber is defined between the plate and the interior surface and a second opening is formed through the plate. An acoustic device is attached to the plate and aligned with the second opening such that the acoustic device is acoustically coupled to the first opening via the acoustic chamber and the second opening. The acoustic chamber has a first region proximate the first opening and a second region proximate the second opening, and a first volume of the first region is larger than a second volume of the second region. 
     In various embodiments the plate is attached to the interior surface with an adhesive layer. In some embodiments the adhesive layer is electrically conductive. In some embodiments a depth of the acoustic chamber is less than a thickness of the acoustic device. In various embodiments a recess is formed in the wall and the plate is positioned over the recess. In some embodiments a depth of the recess and a thickness of an adhesive layer positioned between the plate and the wall define a depth of the acoustic chamber. In various embodiments a protrusion is positioned in the recess and protrudes from a bottom surface of the recess towards the plate. 
     In some embodiments a first area of the first region is larger than a second area of the second region. In various embodiments a center of the first opening is separated from a center of the second opening by a distance greater than 1 millimeter. In some embodiments the electronic device further comprises a flexible circuit disposed between the acoustic device and the plate, wherein the flexible circuit electrically couples the acoustic device to circuitry within the electronic device. In various embodiments the flexible circuit includes a plurality of perforations in a region that aligns with the second opening. In some embodiments the acoustic device is a microphone. In various embodiments the acoustic device is a speaker. 
     In some embodiments an electronic device comprises an enclosure including a front wall positioned opposite a rear wall having an interior surface opposite an exterior surface and a first opening formed through the rear wall. A recess is formed in the rear wall, the recess extending from the interior surface to a second surface. A plate is positioned over the recess and attached to the interior surface with an adhesive layer such that an acoustic chamber is defined between the plate and the interior surface. A second opening is formed through the plate and an acoustic is device attached to the plate and aligned with the second opening such that the acoustic device is acoustically coupled to the first opening via the acoustic chamber and the second opening. A volume of the acoustic chamber changes along a length of the acoustic chamber. 
     In some embodiments the adhesive layer is electrically conductive. In various embodiments a depth of the acoustic chamber is less than a thickness of the acoustic device. In some embodiments the acoustic device is a microphone. In various embodiments the acoustic device is a speaker. In some embodiments the electronic device further comprises a camera module positioned within the enclosure and aligned with the plate. In some embodiments the electronic device further comprises a compressible conductive interface material positioned between the camera module and the plate. 
     To better understand the nature and advantages of the present disclosure, reference should be made to the following description and the accompanying figures. It is to be understood, however, that each of the figures is provided for the purpose of illustration only and is not intended as a definition of the limits of the scope of the present disclosure. Also, as a general rule, and unless it is evident to the contrary from the description, where elements in different figures use identical reference numbers, the elements are generally either identical or at least similar in function or purpose. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an electronic device according to an embodiment of the disclosure; 
         FIG. 2  is a simplified cross-sectional view of a portion of the electronic device shown in  FIG. 1 ; 
         FIG. 3  is simplified plan view of a portion of the electronic device shown in  FIG. 1 ; 
         FIG. 4  is a simplified cross-sectional view of an electronic device similar to the electronic device illustrated in  FIG. 1  according to an embodiment of the disclosure; 
         FIG. 5  is simplified plan view of a portion of the electronic device shown in  FIG. 4 ; and 
         FIG. 6  is a simplified cross-sectional view of an electronic device similar to the electronic device illustrated in  FIGS. 1 and 2  according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments of the present disclosure relate to electronic devices having a limited amount of internal space and that include an internal microphone that is remotely located from a microphone aperture formed in the electronic device enclosure. An acoustic chamber can be formed within the electronic device and used to couple the microphone to the microphone aperture. The acoustic chamber can be configured to compensate for attenuation of a range of frequencies that can occur due to the remote location of the microphone from its corresponding aperture. The acoustic chamber can have a particular length to volume ratio that amplifies a particular range of frequencies such that the microphone maintains equal sensitivity to the desired frequency band of interest. In further embodiments the acoustic chamber can be used with a speaker and a remotely located speaker aperture to compensate for a particular range of frequencies that may be attenuated due to the remote location of the speaker from its corresponding aperture. 
     While the present disclosure can be useful for a wide variety of configurations, some embodiments of the disclosure are particularly useful for electronic devices having little space for internal electrical components, electronic devices having aesthetic requirements that may require an acoustic opening in a particular location and/or for electronic devices that have small form factors, as discussed in more detail below. 
     For example, in some embodiments an electronic device can include an enclosure having a camera aperture on a front side and a microphone aperture on a back side positioned directly opposite the camera aperture. The electronic device may not have adequate internal space to position the internal microphone component in the same location as a camera module so the microphone may be located remotely from the microphone aperture. An acoustic chamber can be formed within the electronic device and used to couple the microphone to the remotely located microphone aperture. The acoustic chamber can be configured to compensate for attenuation of a range of frequencies that can occur due to the remote location of the microphone from the microphone aperture. 
     In some embodiments the acoustic chamber can be defined by a recess formed in an interior surface of the electronic device enclosure that is covered by a plate that extends across the recess and is attached to the interior surface of the enclosure with an adhesive. The microphone can be attached to the plate and aligned with a microphone device aperture within the plate. The microphone can be attached to a flexible circuit that enables it to communicate with other circuitry within the electronic device. 
     In another example the electronic device enclosure and the plate can be made from electrically conductive materials and attached together with an electrically conductive adhesive. An electronic component, such as a camera module, can be grounded to the plate through the adhesive and to the electronic device enclosure. In other examples a protrusion can be positioned within the recess such that it supports the plate from bowing when pressure is applied to it by an adjacent electronic component. 
     In a further example an electronic device can employ an acoustic chamber for use with a speaker and a speaker aperture instead of a microphone with a microphone aperture. More specifically, in some embodiments a speaker can be remotely located from a speaker aperture that allows sound to be ported to an external environment. An acoustic chamber can be disposed between the speaker and the speaker aperture and sized accordingly such that attenuated frequencies are amplified, providing a more uniform loudness for the speaker. 
     In order to better appreciate the features and aspects of electronic devices with microphones located remotely from microphone apertures, further context for the disclosure is provided in the following section by discussing one particular implementation of an electronic device according to embodiments of the present disclosure. These embodiments are for example only and other embodiments may be employed in other electronic devices. 
     For example, any device that receives or transmits audio signals can be used with the disclosure. In some instances, embodiments of the disclosure are particularly well suited for use with portable electronic media devices because of their potentially small form factor and aesthetic requirements. As used herein, an electronic media device includes any device with at least one electronic component that may be used to present human-perceivable media. 
     Such devices may include, for example, wearable electronic devices (e.g., Apple&#39;s watch), portable music players (e.g., MP3 devices and Apple&#39;s iPod devices), portable video players (e.g., portable DVD players), cellular telephones (e.g., smart telephones such as Apple&#39;s iPhone devices), video cameras, digital still cameras, projection systems (e.g., holographic projection systems), gaming systems, PDAs, as well as tablet (e.g., Apple&#39;s iPad devices), laptop or other mobile computers. Some of these devices may be configured to provide audio, video or other data or sensory output. 
       FIG. 1  is front plan view of an example electronic device  100  including an enclosure  105  defining an exterior surface  110 . A screen  115  is attached to a housing  120 , with the combination thereof forming enclosure  105 . Screen  115  functions as an input/output device along with one or more buttons  125  that allow a user to communicate with electronic device  100 . Electronic device  100  further includes a front surface  130  including a camera aperture  135  for capturing images. On a back surface (not shown in  FIG. 1 ) opposite front surface  130 , electronic device  100  includes a microphone aperture  140  that is coupled to an internal microphone (not shown in  FIG. 1 ) that can be used to receive sound from the external environment, as described in more detail below. In the embodiment in  FIG. 1 , camera aperture  135  is located opposite of microphone aperture  140 . 
       FIG. 2  illustrates a simplified cross-sectional view A-A of electronic device  100  illustrated in  FIG. 1 . As shown in  FIG. 2 , cross-section A-A is taken through camera aperture  135  and microphone aperture  140 . A camera module  205  is located within enclosure  105  and is aligned with camera aperture  135 . In the embodiment illustrated in  FIG. 2  an electronic device thickness  210  is not adequate to position microphone  215  directly over microphone aperture  140  so microphone  215  is located to the side of camera module  205  and is displaced horizontally from microphone aperture  140 . Microphone  215  is acoustically coupled to microphone aperture  140  via an acoustic chamber  220 . Acoustic chamber  220  can have a particular size and volume configured to compensate for attenuation of acoustic energy due to the remote location of microphone  215  from microphone aperture  140 , as discussed in more detail below. 
     Acoustic chamber  220  is defined by a recess  225  formed in an interior surface  230  of a rear wall  227  of enclosure  105 . Recess  225  is covered by a plate  235  that extends across the recess and is attached to the interior surface of the enclosure with an adhesive  240 . Acoustic chamber  220  is sealed except for microphone aperture  140  in enclosure  105  and microphone device port  245  formed in plate  235  such that sound can be received by microphone aperture  140  from the external environment and acoustic chamber  220  couples the sound to microphone  215 . 
     In some embodiments microphone  215  is attached to a flexible circuit  250  that is attached to plate  235  with a circuit board adhesive  255 . Flexible circuit  250  can be coupled to a circuit board  260  that enables microphone  215  to communicate with a processor within electronic device  100 . Flexible circuit  250  includes one or more electrical traces that couple circuit board  260  to microphone  215 . 
     In some embodiments flexible circuit  250  includes a plurality of perforations  265  in the region of microphone device port  245  such that acoustic energy can be coupled from acoustic chamber  220  to microphone  215 . In some embodiments the diameter of plurality of perforations  265  have a diameter that allows acoustic energy to be coupled to microphone  215 , but are small enough to act as a filter to prevent debris and contamination from entering the microphone. In one example a diameter of each of plurality of perforations  265  is between 25 and 75 microns. In other embodiments flexible circuit  250  can include a single opening in the region of microphone device port  245  instead of the plurality of perforations. 
     In some embodiments plurality of perforations  265  can be used to obviate the use of an acoustic mesh positioned over microphone aperture  140 . More specifically, since microphone  215  is remotely located from microphone aperture  140  the likelihood of damage to microphone  215  through the microphone aperture is significantly reduced. Further if plurality of perforations  265  are used within flexible circuit  250  to shield debris from entering microphone  215 , there may be no need to apply an acoustic mesh over microphone aperture  140 , resulting in reduced cost and manufacturing complexity. In such embodiments, plate  235  can be coated with a black paint or other material to improve the aesthetics of microphone aperture  140  so a reflective surface is not seen within the microphone aperture. 
     In some embodiments camera module  205  is positioned between plate  235  and enclosure  105  as illustrated in  FIG. 2 . In one embodiment, plate  235  is made from stainless steel and is attached to enclosure  105  with adhesive  240  that is electrically conductive. In some embodiments camera module  205  can be grounded to enclosure  105  by positioning a compressible conductive interface material  270  between camera module  205  and plate  235 . In various embodiments interface material  270  can be an electrically conductive foam or elastomer. In some embodiments adhesive  240  can be eliminated and plate  235  can be attached to enclosure  105  with fasteners, welding or any other joining process. In further embodiments flexible circuit  250  can be extended to provide an interconnect between camera module  205  and other electronics within electronic device  100 . 
     In one embodiment enclosure  105  is made from a metal such as aluminum and recess  225  is machined or cast into interior surface  230 . In other embodiments enclosure  105  can be made from a plastic or any other material. 
     In some embodiments the horizontal displacement of microphone  215  from microphone aperture  140  can result in attenuation of the frequency response of the microphone within a particular frequency range, in particular at the higher end of the frequency range. Acoustic chamber  220  can be designed to compensate for this attenuation such that microphone  215  meets a desired frequency response requirement. More specifically, in some embodiments it may be desirable for microphone  215  to have an equal sensitivity to acoustic signals throughout the audible frequency range. The horizontal displacement of microphone  215  from microphone aperture  140  can act as a quarter wave resonant tube causing a reduction in sensitivity of microphone above the resonant frequency of the resonant tube. 
     To compensate for the reduction in loudness, acoustic chamber  220  can be tuned to resonate at a particular range of frequencies that compensate for the attenuation providing microphone  215  an equal sensitivity to acoustic signals throughout the audible frequency range. More specifically, in some embodiments acoustic chamber  220  can be designed to have a specific volume versus length that enables acoustic energy to be coupled from microphone aperture  140  to microphone  215  without attenuating particular frequencies such that the microphone has an equal sensitivity to acoustic signals throughout a desired frequency range. 
     In some embodiments, acoustic chamber  220  can be particularly useful when a microphone to port distance  275  is 1 millimeter or greater. As microphone to port distance  275  increases above 1 millimeter the attenuation of higher frequencies can increase and the employment of acoustic chamber  220  can be used to compensate for the attenuation. 
     In further embodiments, as microphone to port distance  275  goes beyond 5 millimeters the effectiveness of acoustic chamber  220  may start to diminish. Of course these parameters are for example only and pertain to a particular configuration having a particular geometry. Other configurations will have different useful ranges and this disclosure is not limited to the configurations illustrated herein, but enables one of skill in the art to employ acoustic chambers in both smaller and larger configurations than disclosed herein. For example, in a larger configuration acoustic chambers may be useful when employed in electronic devices that have a microphone to port distance beyond 100 millimeters. Again, the aforementioned parameters are for example only and shall not be used to limit this disclosure to any particular size or configuration. 
       FIG. 3  illustrates a plan view of the embodiment illustrated in  FIG. 2 . As shown in  FIG. 3 , camera module  205 , microphone  215  and plate  235  are illustrated with hidden lines so enclosure  105  and recess  225  can be shown. In this embodiment recess  225  includes a triangularly shaped volume that is defined by a narrow region  305  having a first width  310  near microphone device port  245  and a widened region  315  having a second width  320  positioned near microphone aperture  140 . In some embodiments first width  310  can be between 0.5 and 5 millimeters while in other embodiments it can be between 0.75 and 4 millimeters and in some embodiments between 1 and 3 millimeters. 
     In some embodiments second width  320  can be between 3 and 8 millimeters while in other embodiments it can be between 4 and 7 millimeters and in some embodiments between 5 and 6 millimeters. In some embodiments a length  325  of recess  225  can be between 4 and 9 millimeters while in some embodiments it is between 5 and 8 millimeters and in some embodiments between 6 and 7 millimeters. 
     A depth  280  of recess  225  is illustrated in  FIG. 2  and in some embodiments can be between 0.1 and 1 millimeters while in other embodiments it can be between 0.15 and 0.5 millimeters and in some embodiments between 0.175 and 0.25 millimeters. Adhesive  240  can be used to add depth to acoustic chamber  220  and in some embodiments can have a thickness between 0.03 and 0.3 millimeters while in other embodiments it can be between 0.05 and 0.2 millimeters and in some embodiments between 0.075 and 0.15 millimeters. 
     Although recess  225  is illustrated in  FIG. 3  as having a triangular shape, the recess can have any shape, including but not limited to square, circular, octagonal or rectangular, as described in more detail below. Further, although recess  225  is illustrated in  FIG. 3  has having a uniform thickness, the recess can have any variation of thickness including but not limited to a sloped thickness, a contoured thickness or a stepped thickness, as also described in more detail below. 
     As illustrated in  FIG. 3 , a volume of acoustic chamber  220  (see  FIG. 2 ) can change along microphone to port distance  275 . More specifically, in narrow region  305  positioned proximate microphone device port  245 , an area of acoustic chamber  220  is less than an area in widened region  315  positioned proximate microphone aperture  140 . That is, as shown in  FIG. 3 , dividing acoustic chamber  220  into three regions that include a narrow region  305 , a middle region (positioned between narrow region  305  and widened region  315 ) and a widened region  315 , the area of acoustic chamber  220  is the least at narrow region  305 , the largest at widened region  315  and in-between the least and the largest at the middle region. In this embodiment the volume changes due to the increase in area near widened region  315  and a constant depth, however in other embodiments a change in depth can be used to change the area, as discussed in more detail below. 
     In further embodiments adhesive  240  can be configured to retain its adhesive properties over an extended period of time (e.g., years) so it functions as a particle and debris “getter” within acoustic chamber  220 . More specifically, in one example adhesive  240  is formulated to maintain its “tackiness” and debris that enters acoustic chamber  220  attaches to adhesive  240  so it does not enter microphone  215 . As discussed above, in some embodiments adhesive  240  can be electrically conductive while in other embodiments it can be electrically insulative. Other embodiments can include a different area and/or a similar area of acoustic chamber  220  that is defined by different geometry as discussed in more detail below. 
     In some embodiments plate  235  can be made from a metal such as, for example, stainless steel. In other embodiments plate  235  can be made from a plastic, a ceramic or any other material. In various embodiments plate  235  has a thickness between 0.03 and 1 millimeter while in other embodiments it can be between 0.05 and 0.5 millimeters and in some embodiments between 0.075 and 0.125 millimeters. 
     Flexible circuit  250 , as disclosed herein, describes a circuit that can include an insulating polymer film having conductive circuit patterns affixed thereto and can also include a polymer coating to protect the conductor circuits. Flexible circuits can include a single metal layer, double sided metal layers, multilayer and rigid/flex combination constructions. Flexible circuits can be formed by etching metal foil cladding (normally of copper) from polymer bases, plating metal or printing of conductive inks, among other processes. Flexible circuits can also include one or more electronic passive or active components attached thereto. Flexible circuits can be fabricated using a lamination process that adheres layers together with an adhesive or polymer under pressure, elevated temperature and/or vacuum. 
     Although the embodiment described above in  FIGS. 2 and 3  is described for use with a microphone and the acoustic chamber is configured to compensate for the microphone being displaced from the microphone aperture, other embodiments can employ an acoustic chamber for use with a speaker instead of a microphone. More specifically, in some embodiments a speaker can be displaced from a speaker aperture that allows sound to be ported to an external environment. The distance between the speaker and the speaker aperture can result in attenuation of a certain range of frequencies, in particularly higher frequencies. An acoustic chamber can be disposed between the speaker and the speaker aperture and sized accordingly such that the attenuated frequencies are amplified, providing a more uniform loudness for the speaker as measured at the speaker aperture. 
     Now referring simultaneously to  FIGS. 4 and 5  another embodiment of an electronic device  400  having a microphone  405  displaced horizontally from a microphone aperture  410  is illustrated. The embodiment in  FIGS. 4 and 5  is similar to the embodiment illustrated in  FIGS. 2 and 3 , however in  FIGS. 4 and 5  the area of acoustic chamber  415  is defined by a recess  425  having two different depths. As shown in  FIG. 4 , electronic device  400  includes an enclosure  420  with recess  425  having a first depth  430  and a second depth  435  wherein the first depth is greater than the second depth. 
     As further shown in  FIG. 4 , a camera module  440  is located within enclosure  420  and is aligned with camera aperture  445 . In the embodiment illustrated in  FIG. 4  electronic device  400  does not have adequate thickness to position microphone  405  directly over microphone aperture  410  so microphone  405  is located to the side of camera module  440  and is displaced horizontally from microphone aperture  410 . Microphone  405  is acoustically coupled to microphone aperture  410  via an acoustic chamber  415 . Acoustic chamber  415  can have a particular size and volume configured to compensate for attenuation of acoustic energy due to the remote location of microphone  405  from microphone aperture  410 , as discussed above. 
     Acoustic chamber  415  is defined by recess  425  formed in an interior surface  450  of enclosure  420  that is covered by a plate  455  that extends across the recess and is attached to the interior surface of the enclosure with an adhesive  460 . Acoustic chamber  415  is sealed except for microphone aperture  410  in enclosure  420  and microphone device port  465  formed in plate  455  such that sound can be received by microphone aperture  410  from the external environment and acoustic chamber  415  couples the sound to microphone  405 . 
     In some embodiments recess  425  can include a protrusion  470  positioned in the recess and protruding from a bottom surface of the recess towards plate  455 . Protrusion  470  can be used to provide support for plate  455  in embodiments that apply pressure to plate, such as the embodiment shown in  FIG. 4  having a compressible interface material  475  positioned between camera module  440  and plate  455 . More specifically, in some embodiments compressible interface material  475  can be compressed during assembly of electronic device  400  such that it applies a force on plate  455 . 
     Protrusion  470  can be used to prevent bowing of plate  455  in response to the applied force. In some embodiments protrusion  470  is integrally formed as a portion of enclosure  420 . More specifically, in some embodiments protrusion  470  can be machined into or cast as an integral part of enclosure  420 . In other embodiments protrusion  470  can be a separate component that is welded, glued or mechanically secured to enclosure  420  and/or plate  455 . In one embodiment shown in  FIG. 4 , a portion of adhesive  460  can be used to bond protrusion  470  to plate  455 . 
     As illustrated in  FIGS. 4 and 5 , and as similarly described above, a volume of acoustic chamber  415  can change along the microphone to port distance. More specifically, a first region of acoustic chamber  415  positioned proximate microphone device port  465  is less than an area in a second region that is positioned proximate microphone aperture  410 . That is, as shown in  FIG. 5 , the volume of acoustic chamber  415  increases near microphone aperture  410  due to the increase in depth of the acoustic chamber while the width of the acoustic chamber remains constant. 
     Now referring to  FIG. 5  a plan view of the embodiment illustrated in  FIG. 4  is shown. As shown in  FIG. 5 , camera module  440 , microphone  405  and plate  455  are illustrated with hidden lines so enclosure  420  and recess  425  can be shown. In this embodiment recess  425  includes a rectangularly shaped volume that is defined by a uniform width  505  extending from microphone device port  465  to microphone aperture  410 . As discussed above, acoustic chamber  415  can be designed to compensate for attenuation such that microphone  405  meets a desired frequency response requirement. 
     In some embodiments width  505  of recess  425  can be between 0.5 and 4 millimeters while in other embodiments it can be between 1 and 3 millimeters and in some embodiments between 1.5 and 2.5 millimeters. In some embodiments a length  510  of recess  425  can be between 4 and 9 millimeters while in some embodiments it is between 5 and 8 millimeters and in some embodiments between 6 and 7 millimeters. Now referring to  FIG. 4 , in some embodiments first depth  430  is between 0.03 and 1 millimeter while in other embodiments it can be between 0.05 and 0.5 millimeters and in some embodiments between 0.075 and 0.125 millimeters. In some embodiments second depth  435  is between 0.03 and 1 millimeter while in other embodiments it can be between 0.05 and 0.5 millimeters and in some embodiments between 0.175 and 0.225 millimeters. 
     Although the embodiment described above in  FIGS. 4 and 5  is described for use with a microphone and the acoustic chamber is configured to compensate for the microphone being displaced from the microphone aperture, other embodiments can employ an acoustic chamber for use with a speaker instead of the microphone. More specifically, in some embodiments a speaker may be displaced from a speaker aperture that allows sound to be ported to an external environment. The distance between the speaker and the speaker aperture can result in attenuation of a certain range of frequencies, in particularly higher frequencies. An acoustic chamber can be disposed between the speaker and the speaker aperture and sized accordingly such that the attenuated frequencies are amplified, providing a more uniform loudness for the speaker as measured at the speaker aperture. 
     Now referring to  FIG. 6  another embodiment of an electronic device  600  having a microphone  605  displaced horizontally from a microphone aperture  610  is illustrated. The embodiment in  FIG. 6  is similar to the embodiments illustrated in  FIGS. 2-5 , however in  FIG. 6  a depth  630  of acoustic chamber  615  is defined only by a thickness of adhesive  660  rather than a combination of a depth of a recess formed in the enclosure and the adhesive thickness. As shown in  FIG. 6 , electronic device  600  includes an enclosure  620  that has a uniform interior surface. 
     As further shown in  FIG. 6 , a camera module  640  is located within enclosure  620  and is aligned with camera aperture  645 . In the embodiment illustrated in  FIG. 6  electronic device  600  does not have adequate thickness to position microphone  605  directly over microphone aperture  610  so microphone  605  is located to the side of camera module  640  and is displaced horizontally from microphone aperture  610 . Microphone  605  is acoustically coupled to microphone aperture  610  via acoustic chamber  615 . Acoustic chamber  615  can have a particular size and volume configured to compensate for attenuation of acoustic energy due to the remote location of microphone  605  from microphone aperture  610 , as discussed above. 
     Acoustic chamber  615  is defined by a depth  630  formed between an interior surface  650  of enclosure  620  and a plate  655  that is attached to the interior surface of the enclosure with adhesive  660 . In some embodiments depth  630  of acoustic chamber  615  can be between 0.03 and 1 millimeter while in other embodiments it can be between 0.05 and 0.5 millimeters and in some embodiments between 0.175 and 0.225 millimeters. Acoustic chamber  615  is sealed except for microphone aperture  610  in enclosure  620  and microphone device port  665  formed in plate  655  such that sound can be received by microphone aperture  610  from the external environment and acoustic chamber  615  couples the sound to microphone  605 . 
     Although the embodiment described above in  FIG. 6  is described for use with a microphone and the acoustic chamber is configured to compensate for the microphone being displaced from the microphone aperture, other embodiments can employ an acoustic chamber with a speaker instead of the microphone. More specifically, in some embodiments a speaker can be displaced from a speaker aperture that allows sound to be ported to an external environment. The distance between the speaker and the speaker aperture can result in attenuation of a certain range of frequencies, in particularly higher frequencies. An acoustic chamber can be disposed between the speaker and the speaker aperture and sized accordingly such that the attenuated frequencies are amplified, providing a more uniform loudness for the speaker as measured at the speaker port. 
     For simplicity, various internal components, such as the circuitry, graphics circuitry, bus, memory, storage device and other components of electronic devices  100 ,  400  and  600  are not shown in the figures. 
     In the foregoing specification, embodiments of the disclosure have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the scope of the disclosure, and what is intended by the applicants to be the scope of the disclosure, is the literal and equivalent scope of the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction. The specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of embodiments of the disclosure. 
     Additionally, spatially relative terms, such as “bottom or “top” and the like may be used to describe an element and/or feature&#39;s relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and/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 a “bottom” surface may then be oriented “above” other elements or features. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Metadata:
Filing Date: 20170929
Publication Date: 20181204
Grant Date: 20181204
Priority Date: 20170929
Inventors: FREDERICKSON, AUSTIN
SANDRIK, TIMOTHY E.
HESCHKE, MITCHELL
HAMSTRA, LEE
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/2884", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/2853", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/035", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/2842", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/086", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/2853", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/22", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/2853", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2842", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/086", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/035", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/2884", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/035", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 64452149