PATENT DOCUMENT

Publication Number: US-9579745-B2
Application Number: US-201213598332-A
Country: US
Kind Code: B2

Title: Systems and methods for enhancing performance of a microphone

Abstract:
Systems and methods for enhancing performance of a microphone are disclosed. An airflow control system may include a block-shaped structure and an airflow impedance element residing within a cavity of the block-shaped structure. The airflow impedance element may be formed by filling the cavity with a plurality of pre-processed airflow impedance elements and sintering these elements, and may include a plurality of non-linear pathways. The plurality non-linear pathways may both impede airflow therethrough (e.g., when a force exerted by the airflow exceeds a predetermined amount) and pass sound that may match a frequency response of a microphone without substantially affecting the amplitude and frequency characteristics of the sound.

Claims:
What is claimed is: 
     
       1. An airflow control system for controlling airflow toward a microphone of an electronic device, the airflow control system comprising:
 a planar block-shaped structure bonded between an aperture in an outermost surface of the electronic device and the microphone, comprising a passageway, the passageway comprising:
 a first opening configured to align with the aperture in the outermost surface of the electronic device; and 
 a second opening configured to align with an aperture of the microphone; and 
 
 airflow impedance elements disposed within the passageway and sintered together to form a single structure that is secured within the passageway by a shape of sidewalls defining the passageway, the airflow impedance elements being constructed to control the airflow from the aperture in the outermost surface of the electronic device to the aperture of the microphone. 
 
     
     
       2. The airflow control system of  claim 1 , wherein a central portion of the sidewalls protrudes into the single structure to secure the airflow impedance elements within the passageway. 
     
     
       3. The airflow control system of  claim 1 , wherein the airflow impedance elements form a porous structure. 
     
     
       4. The airflow control system of  claim 1 , wherein the airflow impedance elements are configured to limit speed of airflow through the passageway. 
     
     
       5. The airflow control system of  claim 4 , wherein:
 the airflow impedance element comprises a plurality of non-linear pathways from the first opening to the second opening. 
 
     
     
       6. The airflow control system of  claim 1 , wherein the airflow impedance elements are tuned to match a frequency response of the microphone. 
     
     
       7. The airflow control system of  claim 1 , wherein the airflow impedance elements fill the passageway from the first opening to the second opening. 
     
     
       8. The airflow control system of  claim 1 , wherein the planar block-shaped structure is composed of one of plastic and metal. 
     
     
       9. The airflow control system of  claim 1 , wherein the airflow impedance elements comprise one of polyethylene and polypropylene. 
     
     
       10. A method of manufacturing an airflow control system for a microphone, the method comprising:
 situating a planar block-shaped structure in a heating apparatus, the planar block-shaped structure comprising a passageway having a first opening and a second opening; 
 filling the passageway with pre-processed airflow impedance elements; 
 heating using the heating apparatus the planar block-shaped structure to sinter the filled pre-processed airflow impedance elements together in the passageway, the pre-processed airflow impedance elements being retained within the passageway by a shape of sidewalls defining the passageway; and 
 bonding the planar block-shaped structure between an aperture in an outermost 
 surface of an electronic device and the microphone to couple the first opening to the aperture in the outermost surface of the electronic device and the second opening to an aperture of the microphone. 
 
     
     
       11. The method of  claim 10 , wherein the situating comprises securing at least a portion of the planar block-shaped structure to the heating apparatus. 
     
     
       12. The method of  claim 10 , wherein a central portion of the sidewalls protrudes into the pre-processed airflow impedance elements to retain the pre-processed airflow impedance elements within the passageway. 
     
     
       13. The method of  claim 10 , wherein the heating comprises heating the planar block-shaped structure to approximately 120 degrees Celsius. 
     
     
       14. The method of  claim 10 , wherein filling the passage way comprises inserting pre-processed airflow impedance elements into the passageway through both the first and second openings. 
     
     
       15. The method of  claim 14 , wherein the airflow impedance element is configured to:
 impede airflow that exerts a force beyond a predetermined amount; and 
 pass sound that matches a frequency response of the microphone. 
 
     
     
       16. The method of  claim 10 , wherein the heating comprises inductively heating the structural part. 
     
     
       17. An electronic device comprising:
 a housing comprising a housing aperture in an outermost surface; 
 a circuit board having mounted thereon a microphone, the microphone having a microphone aperture; 
 a planar airflow control system bonded to the housing and the circuit board, the airflow control system fluidically coupling the housing aperture to the microphone aperture by defining a passageway between the housing aperture and the microphone aperture; and 
 sintered airflow impedance elements disposed within the passageway to control airflow through the passageway, the airflow impedance elements being sintered together and retained within the passageway by a shape of sidewalls defining the passageway. 
 
     
     
       18. The electronic device of  claim 17 , wherein the sidewalls define an undercut shape that retains the sintered airflow impedance elements within the passageway. 
     
     
       19. The electronic device of  claim 18 , wherein a second surface of the airflow control system is coupled to the circuit board via a second adhesive. 
     
     
       20. The electronic device of  claim 17 , wherein the airflow impedance elements comprise sintered plastic. 
     
     
       21. The electronic device of  claim 17 , wherein the airflow control system limits speed of airflow applied to the microphone aperture.

Description:
FIELD OF THE INVENTION 
     This can relate to systems and methods for enhancing performance of a microphone. 
     BACKGROUND OF THE DISCLOSURE 
     Many electronic devices include microelectromechanical system (MEMS) components. Sometimes referred to as a micromachine, a MEMS component, such as a MEMS microphone, is smaller than a conventional counterpart, and may thus allow an electronic device to be made smaller. A MEMS microphone may be situated within a housing of an electronic device, such as adjacent to a surface of the housing. One problem with existing MEMS microphones is that, if a MEMS microphone is subjected to forceful airflow (e.g., from a deliberate forceful blasting of compressed air thereon, or from severe environmental conditions, such as extreme winds), air particles of the forceful airflow may be directed up one or more apertures and towards the MEMS microphone. When this occurs, the performance of the microphone may become affected. 
     SUMMARY OF THE DISCLOSURE 
     Systems and methods for enhancing performance of a microphone are provided. 
     In some embodiments, an airflow control system for controlling airflow toward a microphone of an electronic device may be provided. The airflow control system may include a block-shaped structure that may include a passageway. The passageway may include a first opening configured to align with an aperture of the electronic device, and a second opening configured to align with an aperture of the microphone. The airflow control system may also include an airflow impedance element disposed within the passageway and constructed to control the airflow from the first opening to the second opening. 
     In some embodiments, a method of manufacturing an airflow control system for a microphone may be provided. The method may include situating a block-shaped structure in a heating apparatus. The block-shaped structure may include a passageway having a first opening and a second opening. The method may also include filling the passageway with a plurality of pre-processed airflow impedance elements, and heating using the heating apparatus the block-shaped structure to sinter the filled plurality of pre-processed airflow impedance elements in the passageway. 
     In some embodiments, an electronic device may be provided. The electronic device may include a housing that may include a housing aperture. The electronic device may also include a circuit board having mounted thereon a microphone. The microphone may include a microphone aperture. The electronic device may also include an airflow control system secured between the housing and circuit board. The airflow control system may fluidically couple the housing aperture to the microphone aperture and comprises a sintered airflow impedance element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and advantages of the invention will become more apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1A  is a schematic view of an illustrative electronic device, in accordance with at least one embodiment of the invention; 
         FIG. 1B  is a front view of the electronic device of  FIG. 1A , in accordance with at least one embodiment of the invention; 
         FIG. 1C  is a back view of the electronic device of  FIG. 1A , in accordance with at least one embodiment of the invention; 
         FIG. 2  is a cross-sectional view of a portion of the electronic device of  FIG. 1A , in accordance with at least one embodiment of the invention; 
         FIG. 3  is a cross-sectional view of the portion of the electronic device of  FIG. 2 , including an airflow control system, in accordance with at least one embodiment of the invention; 
         FIG. 4A  is a cross-sectional view of a block-shaped structure of the airflow control system of  FIG. 3 , in accordance with at least one embodiment of the invention; 
         FIG. 4B  is a plan view of the block-shaped structure of  FIG. 4A , in accordance with at least one embodiment of the invention; 
         FIG. 4C  is a cross-sectional view of the block-shaped structure of  FIG. 4A , including a plurality of pre-processed airflow impedance elements, in accordance with at least one embodiment of the invention; 
         FIG. 5A  shows a cross-sectional view of the block-shaped structure of  FIG. 4A  undergoing filling and processing of the plurality of pre-processed airflow impedance elements of  FIG. 4C , in accordance with at least one embodiment of the invention; 
         FIG. 5B  shows a cross-sectional view of the block-shaped structure of  FIG. 4A  undergoing another filling and processing of the plurality of pre-processed airflow impedance elements of  FIG. 4C , in accordance with at least one embodiment of the invention; 
         FIG. 6  is an illustrative process of manufacturing the airflow control system of  FIG. 3 , in accordance with at least one embodiment of the invention; and 
         FIG. 7  is an illustrative process of integrating the airflow control system of  FIG. 3  to the portion of the electronic device of  FIG. 2 , in accordance with at least one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Systems and methods for enhancing performance of a microphone are provided and described with reference to  FIGS. 1-7 . 
       FIG. 1  is a schematic view of an illustrative electronic device  100  that may couple to and be used with a listening device by a user. In some embodiments, electronic device  100  may perform a single function (e.g., a device dedicated to storing image content) and, in other embodiments, electronic device  100  may perform multiple functions (e.g., a device that stores image content, plays music, and receives and transmits telephone calls). Moreover, in some embodiments, electronic device  100  may be any portable, mobile, or hand-held electronic device configured to control output of content. Alternatively, electronic device  100  may not be portable at all, but may instead be generally stationary. Electronic device  100  may include any suitable type of electronic device operative to control output of content. For example, electronic device  100  may include a media player (e.g., an iPod™ available by Apple Inc. of Cupertino, Calif.), a cellular telephone (e.g., an iPhone™ available by Apple Inc.), a personal e-mail or messaging device (e.g., a Blackberry™ available by Research In Motion Limited of Waterloo, Ontario), any other wireless communication device, a pocket-sized personal computer, a personal digital assistant (“PDA”), a tablet, a laptop computer, a desktop computer, a music recorder, a still camera, a movie or video camera or recorder, a radio, medical equipment, any other suitable type of electronic device, and any combinations thereof. 
     Electronic device  100  may include a processor or control circuitry  102 , memory  104 , communications circuitry  106 , power supply  108 , input component  110 , output component  112 , and a detector  114 . Electronic device  100  may also include a bus  103  that may provide a transfer path for transferring data and/or power, to, from, or between various other components of device  100 . In some embodiments, one or more components of electronic device  100  may be combined or omitted. Moreover, electronic device  100  may include other components not combined or included in  FIG. 1 . For example, electronic device  100  may include motion detection circuitry, light sensing circuitry, positioning circuitry, or several instances of the components shown in  FIG. 1 . For the sake of simplicity, only one of each of the components is shown in  FIG. 1 . 
     Memory  104  may include one or more storage mediums, including for example, a hard-drive, flash memory, permanent memory such as read-only memory (“ROM”), semi-permanent memory such as random access memory (“RAM”), any other suitable type of storage component, or any combination thereof. Memory  104  may include cache memory, which may be one or more different types of memory used for temporarily storing data for electronic device applications. Memory  104  may store media data (e.g., music, image, and video files), software (e.g., for implementing functions on device  100 ), firmware, preference information (e.g., media playback preferences), lifestyle information (e.g., food preferences), exercise information (e.g., information obtained by exercise monitoring equipment), transaction information (e.g., information such as credit card information), wireless connection information (e.g., information that may enable device  100  to establish a wireless connection), subscription information (e.g., information that keeps track of podcasts or television shows or other media a user subscribes to), contact information (e.g., telephone numbers and e-mail addresses), calendar information, any other suitable data, or any combination thereof. 
     Communications circuitry  106  may be provided to allow device  100  to communicate with one or more other electronic devices or servers using any suitable communications protocol. For example, communications circuitry  106  may support Wi-Fi (e.g., an 802.11 protocol), Ethernet, Bluetooth™, high frequency systems (e.g., 900 MHz, 2.4 GHz, and 5.6 GHz communication systems), infrared, transmission control protocol/internet protocol (“TCP/IP”) (e.g., any of the protocols used in each of the TCP/IP layers), hypertext transfer protocol (“HTTP”), BitTorrent™, file transfer protocol (“FTP”), real-time transport protocol (“RTP”), real-time streaming protocol (“RTSP”), secure shell protocol (“SSH”), any other communications protocol, or any combination thereof. Communications circuitry  106  may also include circuitry that can enable device  100  to be electrically coupled to another device (e.g., a computer or an accessory device) and communicate with that other device, either wirelessly or via a wired connection. 
     Power supply  108  may provide power to one or more of the other components of device  100 . In some embodiments, power supply  108  can be coupled to a power grid (e.g., when device  100  is not a portable device, such as a desktop computer). In some embodiments, power supply  108  can include one or more batteries for providing power (e.g., when device  100  is a portable device, such as a cellular telephone). As another example, power supply  108  can be configured to generate power from a natural source (e.g., solar power using solar cells). 
     One or more input components  110  may be provided to permit a user to interact or interface with device  100 . For example, input component  110  can take a variety of forms, including, but not limited to, an electronic device pad, dial, click wheel, scroll wheel, touch screen, one or more buttons (e.g., a keyboard), mouse, joy stick, track ball, a microphone, and combinations thereof. For example, input component  110  may include a multi-touch screen. Each input component  110  can be configured to provide one or more dedicated control functions for making selections or issuing commands associated with operating device  100 . 
     Electronic device  100  may also include one or more output components  112  that may present information (e.g., textual, graphical, audible, and/or tactile information) to a user of device  100 . Output component  112  of electronic device  100  may take various forms, including, but not limited, to audio speakers, in-ear earphones, headphones, audio line-outs, visual displays, antennas, infrared ports, rumblers, vibrators, or combinations thereof. 
     For example, output component  112  of electronic device  100  may include an image display  112  as an output component. Such an output component display  112  may include any suitable type of display or interface for viewing image data captured by detector  114 . In some embodiments, display  112  may include a display embedded in device  100  or coupled to device  100  (e.g., a removable display). Display  112  may include, for example, a liquid crystal display (“LCD”), a light emitting diode (“LED”) display, an organic light-emitting diode (“OLED”) display, a surface-conduction electron-emitter display (“SED”), a carbon nanotube display, a nanocrystal display, any other suitable type of display, or combination thereof. Alternatively, display  112  can include a movable display or a projecting system for providing a display of content on a surface remote from electronic device  100 , such as, for example, a video projector, a head-up display, or a three-dimensional (e.g., holographic) display. 
     In some embodiments, output component  112  may include an audio output module that may be coupled to an audio connector (e.g., a male audio jack) for interfacing with an audio device (e.g., a headphone, an in-ear earphone, a microphone, etc.). 
     It should be noted that one or more input components  110  and one or more output components  112  may sometimes be referred to collectively herein as an I/O interface (e.g., input component  110  and output component  112  as I/O interface  111 ). It should also be noted that input component  110  and output component  112  may sometimes be a single I/O component, such as a touch screen that may receive input information through a user&#39;s touch of a display screen and that may also provide visual information to a user via that same display screen. 
     Detector  114  may include one or more sensors of any suitable type that may capture human recognition data (e.g., face data) that may be utilized to detect the presence of one or more individuals. For example, detector  114  may include an image sensor and/or an infrared sensor. The image sensor may include one or more cameras with any suitable lens or number of lenses that may be operative to capture images of the surrounding environment of electronic device  100 . For example, the image sensor may include any number of optical or digital lenses for capturing light reflected by the device&#39;s environment as an image. The captured light may be stored as an individual distinct image or as consecutive video frame images of a recording (e.g., several video frames including a primary frame and one or more subsequent frames that may indicate the difference between the primary frame and the subsequent frame). As used herein, the term “camera lens” may be understood to mean a lens for capturing light or a lens and appropriate circuitry for capturing and converting captured light into an image that can be analyzed or stored by electronic device  100  as either an individual distinct image or as one of many consecutive video frame images. 
     In some embodiments, detector  114  may also include one or more sensors that may detect any human feature or characteristic (e.g., physiological, psychological, physical, movement, etc.). For example, detector  114  may include a microphone for detecting voice signals from one or more individuals. As another example, detector  114  may include a heartbeat sensor for detecting heartbeats of one or more individuals. As yet other examples, detector  114  may include a fingerprint reader, an iris scanner, a retina scanner, a breath sampler, and a humidity sensor that may detect moisture and/or sweat emanating from any suitable portion of an individual&#39;s body. For example, detector  114  may include a humidity sensor that may be situated near or coupled to one or more portions of input component  110 , and that may detect moisture and/or sweat from an individual&#39;s hands. It should be appreciated that any detector  114  may include any sensor that may detect any human feature or characteristic. 
     In some embodiments, detector  114  may also include positioning circuitry for determining a current position of device  100 . The positioning circuitry may be operative to update the current position at any suitable rate, including at relatively high rates to provide an estimation of speed and distance traveled. In some embodiments, the positioning circuitry may include a global positioning system (“GPS”) receiver for accessing a GPS application function call that may return geographic coordinates (i.e., a geographic location) of the device. The geographic coordinates may be fundamentally, alternatively, or additionally, derived from any suitable trilateration or triangulation technique. For example, the positioning circuitry may determine the current location of device  100  by using various measurements (e.g., signal-to-noise ratio (“SNR”) or signal strength) of a network signal (e.g., a cellular telephone network signal) that may be associated with device  100 . For example, a radio frequency (“RF”) triangulation detector or sensor integrated with or connected to device  100  may determine the (e.g., approximate) current location of device  100 . Device  100 &#39;s current location may be determined based on various measurements of device  100 &#39;s own network signal, such as, for example: (1) an angle of the signal&#39;s approach to or from one or more cellular towers, (2) an amount of time for the signal to reach one or more cellular towers or device  100 , (3) the strength of the signal when it reaches one or more towers or device  100 , or any combination of the aforementioned measurements. Other forms of wireless-assisted GPS (e.g., enhanced GPS or A-GPS) may also be used to determine the current position of device  100 . Instead or in addition, the positioning circuitry may determine the current location of device  100  based on a wireless network or access point that may be in range or a wireless network or access point to which device  100  may be currently connected. For example, because wireless networks may have a finite range, a wireless network that may be in range of device  100  may indicate that device  100  is located in within a detectable vicinity of the wireless network. In some embodiments, device  100  may automatically connect to a wireless network that may be in range in order to receive valid modes of operation that may be associated or that may be available at the current position of device  100 . 
     In some embodiments, detector  114  may also include motion sensing circuitry for detecting motion of an environment of device  100  and/or objects in the environment. For example, the motion sensing circuitry may detect a movement of an object (e.g., an individual) about device  100  and may generate one or more signals based on the detection. 
     Processor  102  of device  100  may control the operation of many functions and other circuitry provided by device  100 . For example, processor  102  may receive input signals from input component  110  and/or drive output signals through display  112 . Processor  102  may load a manager program (e.g., a program stored in memory  104  or another device or server accessible by device  100 ) to process or analyze data received via detector  114  or inputs received via input component  110  to control output of content that may be provided to the user via output component  112  (e.g., display  112 ). Processor  102  may associate different metadata with the human recognition data captured by detector  114 , including, for example, positioning information, device movement information, a time code, a device identifier, or any other suitable metadata. Electronic device  100  (e.g., processor  102 , any circuitry of detector  114 , or any other component available to device  100 ) may be configured to capture data with detector  114  at various resolutions, frequencies, intensities, and various other characteristics as may be appropriate for the capabilities and resources of device  100 . 
     Electronic device  100  may also be provided with a housing  101  that may at least partially enclose one or more of the components of device  100  for protecting them from debris and other degrading forces external to device  100 . In some embodiments, one or more of the components may be provided within its own housing (e.g., input component  110  may be an independent keyboard or mouse within its own housing that may wirelessly or through a wire communicate with processor  102 , which may be provided within its own housing). 
     Electronic device  100  may include one or more microphones (e.g., as part of I/O interface  111 ) for capturing sounds from the environment (e.g., a user&#39;s voice). It should be appreciated that various criteria may be used to select the type of microphone for inclusion in an electronic device. For example, it is preferable to use microphones that draw minimal power, that are compact, and that are easy to manufacture and integrate in into electronic devices. As another example, it is important to choose a microphone that provides a good frequency response. For example, a microphone may have a good frequency response if it can receive sounds over a range of frequencies that are audible to humans. MEMS microphones provide one or more of these features. For example, MEMS microphones are smaller than conventional counterparts, and may allow an electronic device to be made smaller. They are also easy to integrate into electronic devices and can provide good frequency responses. 
       FIG. 1B  is a front view of electronic device  100 . As shown in  FIG. 1B , housing  101  may at least partially enclose I/O interface  111 . Moreover, housing  101  may include a microphone  160  (e.g., a MEMs microphone) and an aperture  120  through a portion of housing  101  (e.g., cut through a glass portion of housing  101 ). Aperture  120  may be situated on a bottom surface of electronic device  100  and may face the −Y direction. Microphone  160  may be situated within housing  101  and adjacent aperture  120  such that, when a user holds electronic device  100  close to the user&#39;s face, sound from the user&#39;s mouth may pass through aperture  120  and travel towards microphone  160 . 
     Although typical electronic devices may only include a single microphone, electronic device  100  may include a plurality of microphones. For example, electronic device  100  may include an aperture  122  through another portion of housing  101  (e.g., cut through a glass portion of housing  101 ) and may, in addition to microphone  160 , include a microphone  161  (e.g., another MEMS microphone). Aperture  122  may be situated on a front surface of housing  101  (e.g., adjacent a receiver  130  that may be a component of detector  114 ) and may face the +Z direction. Microphone  161  may be situated within housing  101  and adjacent aperture  122  such that, when a user holds electronic device  100  up with the front surface facing the user (e.g., during a video conference using a camera  132  of electronic device  100 ), sound from the user&#39;s mouth may pass through aperture  122  and travel towards microphone  161 . Situating microphone  161  on the front surface of housing  101  may more efficiently capture sound during such a video conference call, since the sound from the user&#39;s mouth may not be sufficiently directed towards the bottom surface of housing  101  for microphone  160  to capture. 
       FIG. 1C  is a back view of electronic device  100 . As shown in  FIG. 1C , electronic device  100  may include an aperture  124  through another portion of housing  101  (e.g., cut through a glass portion of housing  101 ) and may, in addition to microphones  160  and  161 , include a microphone  162  (e.g., yet another MEMS microphone). Aperture  124  may be situated on a back surface of housing  101  (e.g., near a top portion of the back surface) and may face the −Z direction. Microphone  162  may be situated within housing  101  and adjacent aperture  124  such that, when a user holds electronic device  100  up with the back surface facing the user (e.g., during a video conference using a camera  134  of electronic device  100 ), sound from the user&#39;s mouth may pass through aperture  124  and travel towards microphone  162 . Situating microphone  162  on the back surface of housing  101  may more efficiently capture sound during such a video conference call, since the sound from the user&#39;s mouth may not be sufficiently directed towards the front or bottom surfaces of housing  101  for any of microphones  160  and  161  to capture. 
     One problem with existing MEMS microphones is that, if a MEMS microphone is subjected to forceful airflow (e.g., from a deliberate forceful blasting of compressed air thereon, or from severe environmental conditions, such as extreme winds), air particles of the forceful airflow may be directed up one or more apertures of an electronic device as a pressure wave towards the microphone. For example, when forceful airflow is directed into an aperture (e.g., any one of apertures  120 ,  122 , and  124 ) of electronic device  100 , air particles of the forceful airflow may be directed at a corresponding microphone (e.g., a corresponding one of microphones  160 ,  161 , and  162 ). If the force of the airflow exceeds a predetermined amount, the performance of the microphone may decrease. 
       FIG. 2  is a cross-sectional view of a portion of electronic device  100 . The portion may include a portion of housing  101  having aperture  120 , which may face the −Y direction. Housing  101  may include external surface side  101   e  and internal surface side  101   i , and aperture  120  may extend from external surface side  101   e  to internal surface side  101   i . A circuit board  170  (e.g., a flexible circuit board) may be situated adjacent internal surface side  101   i  and may include a microphone  160  that may be attached thereto. As described above, microphone  160  may be a MEMS microphone. Microphone  160  may include microphone aperture  160   a  for receiving sound (e.g., from a user&#39;s voice). Housing  101 , circuit board  170 , and microphone  160  may be aligned with respect to each other in any suitable manner.  FIG. 2  shows these components aligned such that sound, that may enter housing  101  through aperture  120  in the +Y direction, may travel through housing aperture  120  and microphone aperture  160   a  into microphone  160 , in this order. 
     Microphone  160  may include a diaphragm (not shown) that may receive the sound, and may process the received sound and/or send the received sound to processor  102  for processing. The performance of one or more components of microphone  160  (e.g., the diaphragm) may be affected, for example, when airflow is forcefully directed at microphone  160 , at or above a predefined force F. The forceful airflow may cause air particles to travel through aperture  120  in the +Y direction and towards microphone  160 . It should be appreciated that, although  FIG. 2  only shows microphone  160 , the performance of any one of microphones  161  and  162  may also be affected by forceful airflow. 
       FIG. 3  is a cross-sectional view of the portion of electronic device  100  of  FIG. 2 , including a cross-section view of an airflow control system  300 . Airflow control system  300  may, for example, be included in electronic device  100  to enhance the performance of microphone  160 . For example, airflow control system  300  may prevent deliberate and/or forceful airflow from interfering with the operation of microphone  160 . As another example, airflow control system  300  may reduce undesired noise (e.g., from windy conditions in an outdoor environment) from being detected by microphone  160 . Airflow control system  300  may include block-shaped structure  302  having a cavity  310  that may extend from an opening  320  to an opening  322  of block-shaped structure  302 . Airflow control system  300  may also include an airflow impedance element  304  that may reside within cavity  310  (e.g., throughout an entirety of cavity  310 ). Airflow control system  300  may be sandwiched by adhesives  180  and  190  that may be included to attach airflow control system  300  to housing  101  and circuit board  170 , respectively. Adhesives  180  and  190  may include cut-outs  182  and  192 , respectively, and may be aligned with housing  101 , airflow control system  300 , circuit board  170 , and microphone  160  in any suitable manner.  FIG. 3  shows these components aligned such that sound (e.g., from a user&#39;s voice), that may enter housing  101  through aperture  120  in the +Y direction, may travel through housing aperture  120 , cut-out  182 , airflow impedance element  304 , cut-out  192 , and microphone aperture  160   a  into microphone  160 , in this order. Although  FIG. 3  may show these various components aligned in a particular manner, any one of these components may be shifted from one another in any of the −X, +X, −Y, +Y, +Z, and −Z directions, as long as sound may travel from outside of housing  101  into microphone  160  in the +Y direction. 
     Block-shaped structure  302  may include any suitable type of material. In some embodiments, block-shaped structure  302  may be composed of injection molded plastic (e.g., PPA, LCP, or other high temperature resin). Block-shaped structure  302  may be shaped and sized for integration between microphone  160  and housing  101  based design or spacing requirements. Cavity  310  may initially be empty and may be sized and shaped for subsequent filling of airflow impedance element  304  therein. 
     Airflow impedance element  304  may be a single structure that may be formed from a plurality of pre-processed airflow impedance elements. For example, the plurality of pre-processed airflow impedance elements may include substantially round or bead-like elements that may have any suitable size (e.g., approximately 50 um in diameter each). Airflow impedance element  304  may be composed of any suitable material (e.g., polyethylene, polypropylene, etc.) and may be formed when the plurality of pre-processed airflow impedance elements are subjected to specific processing (e.g., a heating or sintering process). 
     The plurality of pre-processed airflow impedance elements may be soft and/or flexible enough to change shape or other properties when subjected to the processing. For example, during a heating or sintering process, the plurality of pre-processed airflow impedance elements may at least partially fuse to form airflow impedance element  304  (e.g., as a single structure). Because each of the plurality of pre-processed airflow impedance elements may initially be substantially round, a plurality of pores or pathways may form throughout airflow impedance element  304  as a result of the fusion. For example, the pathways may run from one surface of airflow impedance element  304  (e.g., the surface closest to external surface side  101   e  of housing  101 ) to another surface of airflow impedance element  304  (e.g., the surface closest to circuit board  170 ) so as to allow sound to pass in direction +Y. In this manner, when airflow impedance element  304  is disposed between aperture  120  and microphone  160  (e.g., as shown in  FIG. 3 ), airflow impedance element  304  may fluidically couple aperture  120  and microphone aperture  160   a  (e.g., to allow fluid, or air particles, to pass from aperture  120  to microphone aperture  160   a ). 
     It should be appreciated that each pathway may or may not run from one surface of airflow impedance element  304  to another surface in a straight manner, but may traverse around or between particular ones of the fused plurality of airflow impedance elements in a plurality of directions to form a lengthened pathway. A lengthened pathway may provide an impedance effect on airflow through airflow impedance element  304  (e.g., from aperture  120  to microphone  160 ). For example, air particles from airflow that may typically flow directly through aperture  120  to microphone  160  (as shown in  FIG. 2 ) may be forced to traverse longer non-linear pathways when airflow impedance element  304  is disposed between aperture  120  and microphone  160  (as shown in  FIG. 3 ). When the air particles traverse these lengthened and non-linear pathways, they may contact walls of these pathways (e.g., surfaces of the fused plurality of airflow impedance elements), which may act to slow the air particles down. Thus, when microphone  160  is subjected to forceful airflow, the corresponding force (or speed) of air particles, that may otherwise affect the performance of microphone  160 , may be substantially attenuated by these non-linear lengthened pathways of airflow impedance element  304 . 
     As described above, microphones are typically designed or tuned to a specific frequency response, where sound within a certain range of frequencies are captured with minimal loss of amplitude. Accordingly, although it may be important to impede forceful airflow from affecting the performance of microphone  160 , it may also be important to allow microphone  160  to successfully capture sound (e.g., air particles traveling in the range of frequencies that microphone  160  is tuned to capture). Thus, the non-linear lengthened pathways may also allow the air particles to successfully flow through airflow impedance element  304  with minimal effect to their respective frequency characteristics. For example, the non-linear lengthened pathways of airflow impedance element  304  may allow sound in human audible frequencies to pass through with minimal effect on its frequency and amplitude. Thus, airflow impedance element  304  may be constructed to both impede forceful airflow therethrough and match the frequency response of microphone  160 . 
     It should be appreciated that any of the materials, the number of, and/or the size of the plurality of pre-processed elements (prior to heating or sintering thereof to form airflow impedance element  304 ) may be controlled to provide an airflow impedance element  304  that may both impede forceful airflow therethrough and match the frequency response of microphone  160 . For example, pre-processed airflow impedance elements of certain materials may form more suitable pathways than others (e.g., materials that do not sinter well may not produce sufficient pathways that both impede forceful airflow therethrough and match the frequency response of microphone  160 ). 
     It should also be appreciated that any of the parameters of the heating or sintering process, the size of block-shaped structure  302 , and the size of cavity  310  may also be controlled to provide an airflow impedance element  304  that may both impede forceful airflow therethrough and match the frequency response of microphone  160 . For example, environmental parameters used during processing (e.g., heating or sintering) of the plurality of pre-processed airflow impedance elements may be set to form suitable pathways in the resulting airflow impedance element  304  (e.g., if too high or too low of a temperature is used to sinter the plurality of pre-processed airflow impedance elements, the desired pathways may or may not be produced, may or may not be produced in sufficient quantity, and/or may or may not be characterized so as to both impede forceful airflow therethrough and match the frequency response of microphone  160 ). As another example, the size and shape of cavity  310  may need to be configured to contain a suitable amount of the plurality of pre-processed airflow impedance elements and to house the resulting airflow impedance element  304  (e.g., if cavity  310  is too small or too large, air particles (e.g., at force F) may not be sufficiently impeded to enhance the performance of microphone  160 ). 
     In some embodiments, block-shaped structure  302  may be mounted to circuit board  170  (e.g., via adhesive  190  that may be applied as solder) during manufacturing of circuit board  170 . Circuit board  170  may then undergo reflow processing to thoroughly solder and fix block-shaped structure  302  to circuit board  170 ). In this manner, production of electronic device  100  may be made simpler since only a single assembly or part may need to be attached to housing  101  (e.g., via adhesive  180 ) during manufacturing of electronic device  100 . In these embodiments, block-shaped structure  302  may be at least partially composed of metal (e.g., stainless steel) in order to withstand high temperatures used during the reflow processing. In addition, the material of the plurality of pre-processed elements may also need to be selected such that the resulting airflow impedance element  304  may also withstand the high temperatures during the reflow processing. 
       FIG. 4A  is a cross sectional view of block-shaped structure  302 , prior to element  304  being formed therein.  FIG. 4B  is a plan view of block-shaped structure  302 . Block-shaped structure  302  may have any suitable thickness, and may include cavity  310  for retaining pre-processed airflow impedance elements. Cavity  310  may be shaped to efficiently receive the pre-processed airflow impedance elements during filling thereof. For example, cavity  310  may include differently sized sections  311 ,  312 , and  313  having relatively sharp edges E. Each of sections  311 ,  312 , and  313  may be sized to retain a predetermined amount of pre-processed airflow impedance elements. It should be appreciated that, although  FIG. 4A  shows cavity  310  having an irregular shape, cavity  310  may take any other suitable shape. For example, instead of having sharp edges E, cavity  310  may have an hourglass shape with smoother edges. With smoother edges, cavity  310  may be more easily filled with the pre-processed airflow impedance elements. Moreover, the shape of cavity  310  (e.g., the undercut shape of cavity  310 , as shown in  FIGS. 3-5B ) may prevent filled pre-processed airflow impedance elements from escaping block-shaped structure  302  once they have been processed (e.g., heated/sintered) to form airflow impedance element  304 . 
       FIG. 4C  is a cross-sectional view of block-shaped structure  302 , including a plurality of pre-processed airflow impedance elements  305  residing therein. Although only a cross-section of block-shaped structure  302  is shown, it should be appreciated that pre-processed airflow impedance elements  305  may substantially fill the entirety of cavity  310 . As described above with respect to  FIG. 3 , airflow control system  300  may be configured to match the frequency response of microphone  160 . In particular, the physical configuration of cavity  310  and of each one of pre-processed airflow impedance elements  305  may be defined based on the frequency response of microphone  160 . For example, the size of sections  311 ,  312 , and  313  may each be defined to retain a predetermined amount of pre-processed airflow impedance elements  305 , such that the non-linear pathways, that may form throughout as a result of fusion of pre-processed airflow impedance elements  305 , may allow human audible sound to pass. 
       FIG. 5A  shows a cross-sectional view of block-shaped structure  302  undergoing filling and processing of pre-processed airflow impedance elements  305 . As shown in  FIG. 5A , block-shaped structure  302  may be situated in an oven  510 . Oven  510  may include a feeding surface  520  for feeding pre-processed airflow impedance elements  305  into cavity  310 . For example, as pre-processed airflow impedance elements are placed onto feeding surface  520 , these pre-processed airflow impedance elements  305  may be directed (e.g., by gravity) down feeding surface  520  in a direction S into cavity  310 . Oven  510  may also include a vibrating mechanism (not shown) that may vibrate block-shaped structure  302  during and/or after feeding of pre-processed airflow impedance elements  305 . In this manner, pre-processed airflow impedance elements  305  may thoroughly occupy and settle throughout sections  311 ,  312 , and  313  of cavity  310 . During and/or after feeding of pre-processed airflow impedance elements  305 , oven  510  may also be configured to generate heat (e.g., at a temperature of 120 degrees Celsius) around block-shaped structure  302 . As a result, pre-processed airflow impedance elements  305  may fuse or sinter to form airflow impedance element  304 , as described above. 
     Although  FIG. 5A  shows block-shaped structure  302  being situated directly on oven  510 , in some embodiments, block-shaped structure  302  may instead be situated on a frame (not shown) that may be in contact with oven  510 . Further, in some embodiments, the vibrating mechanism may be separate (not shown) from oven  510  rather than being a part of oven  510 . 
       FIG. 5B  shows a cross-sectional view of block-shaped structure  302  undergoing another filling and processing of pre-processed airflow impedance elements  305 . As an alternative to filling pre-processed airflow impedance elements  305  into cavity  310  from a single direction (e.g., as shown in  FIG. 5A ), block-shaped structure  302  may also be filled with pre-processed airflow impedance elements  305  from a plurality of directions. For example, block-shaped structure  302  may be rotated to stand as shown in  FIG. 5B , and may be situated on an oven  550 . Oven  550  may include feeding surfaces  552  and  554 , which may each be similar to feeding surface  520  of oven  510 , for feeding pre-processed airflow impedance elements  305  into cavity  310 . As pre-processed airflow impedance elements  305  are placed onto feeding surfaces  552  and  554 , these pre-processed airflow impedance elements  305  may be directed (e.g., by gravity) down feeding surfaces  552  and  554 , in directions T and U, respectively, into cavity  310 . This manner of filling may ensure that cavity  310  is thoroughly filled with pre-processed airflow impedance elements  305 . 
     In some embodiments, after pre-processed airflow impedance elements  305  are filled and processed as shown in  FIG. 5B  (e.g., to form airflow impedance element  304 ), excess portions of the processed element may reside or be adhered to outer surfaces of block-shaped structure  302 . Thus, when block-shaped structure  302  is removed from oven  550 , these outer surfaces of block-shaped structure  302  may be brushed or shaved to remove these excess portions. 
       FIG. 6  is an illustrative process of manufacturing airflow control system  300 . Process  600  may begin at step  602 . 
     At step  604 , the process may include situating a block-shaped structure in a heating apparatus, the block-shaped structure including a cavity having a first opening and a second opening. For example, step  604  may include situating block-shaped structure  302  in oven  510 , as shown in  FIG. 5A . Block-shaped structure  302  may include cavity  310  that have openings  320  and  322 . 
     At step  606 , the process may include filling the cavity with a plurality of pre-processed airflow impedance elements. For example, step  606  may include filling cavity  310  with the plurality of pre-processed airflow impedance elements  305 . In some embodiments, oven  510  may be vibrated during the filling of the plurality of pre-processed airflow impedance elements  305 . For example, a vibrating machine may be coupled to oven  510  and the process may include vibrating oven  510  prior to, during, and/or after the plurality of pre-processed airflow impedance elements  305  are filled into cavity  310 . This vibration may allow the plurality of pre-processed airflow impedance elements  305  to thoroughly fill cavity  310  so as to form a uniform sintered block when the plurality of pre-processed airflow impedance elements  305  are subjected to heat. As part of vibrating oven  510 , force may be applied to one or more portions of block-shaped structure  302  in order to keep block-shaped structure  302  fixed to oven  510 . 
     At step  608 , the process may include heating using the heating apparatus the block-shaped structure to sinter the filled plurality of pre-processed airflow impedance elements in the cavity. For example, step  608  may include heating using oven  510  block-shaped structure  302  to sinter the filled plurality of pre-processed airflow impedance elements  305  in cavity  310 . It should be appreciated that the heating can occur during and/or after filling the plurality of pre-processed airflow impedance elements  305  into cavity  310 . 
     In some embodiments, block-shaped structure  302  may be composed of plastic material or the like. In these embodiments, the process may include heating block-shaped structure  302  and the plurality of pre-processed airflow impedance elements  305  to a particular temperature (e.g., just enough to sinter the plurality of pre-processed airflow impedance elements  305  to create the non-linear pathways described above) oven  510 . For example, the process may include heating the plurality of pre-processed airflow impedance elements  305  at approximately 120 degrees Celsius. In other embodiments, block-shaped structure  302  may be at least partially composed of metal or the like. In these embodiments, the process may include heating block-shaped structure  302  via inductive heating, which may provide a consistent temperature throughout block-shaped structure  302 . As a result of such inductive heating, the plurality of pre-processed airflow impedance elements  305  may be indirectly heated and sintered. 
     In some embodiments, instead of filling pre-processed airflow impedance elements  305  into cavity  310  from a single direction (e.g., as shown in and described above with respect to  FIG. 5A ), pre-processed airflow impedance elements  305  may be filled from a plurality of directions (e.g., as shown in and described above with respect to  FIG. 5B ). For example, step  604  may include positioning block-shaped structure  302  upright in oven  550 , and step  606  may include filling pre-processed airflow impedance elements  305  from both sides of block-shaped structure  302 . In these embodiments, there may not be a need to vibrate pre-processed airflow impedance elements  305  during filling thereof. Step  608  may then include sintering pre-processed airflow impedance elements  305  to form airflow impedance element  304 . 
       FIG. 7  is an illustrative process of integrating airflow control system  300  with electronic device  100 . Process  700  may begin at step  702 . At step  704 , the process may include aligning an airflow control system with a circuit board and microphone of an electronic device. For example, the process may include aligning airflow control system  300  with circuit board  170  and microphone  160  (which may be situated on circuit board  170 ) such that airflow impedance element  304  of airflow control system  300  may at least partially overlap with microphone aperture  160   a  in a particular direction (e.g., in the +Y or −Y directions of  FIG. 3 ). 
     At step  706 , the process may include coupling the airflow control system to the circuit board based on the aligning. For example, the process may include applying adhesive  190  between circuit board  170  and a top surface of airflow control system  300  to secure airflow control system  300  to circuit board  170 . In some embodiments, adhesive  190  may be formed by cutting out an adhesive sheet such that adhesive  190  may include cut-out  192 . 
     At step  708 , the process may include arranging the airflow control system with a housing aperture of the electronic device. For example, the process may include arranging airflow control system  300  with housing aperture  120  such that airflow impedance element  304  of airflow control system  300  may at least partially overlap with housing aperture  120  in a particular direction (e.g., in the +Y or −Y directions of  FIG. 3 ). 
     At step  710 , the process may include coupling the airflow control system to a portion of a housing of the electronic device based on the arranging. For example, the process may include applying adhesive  180  between a bottom surface of airflow control system  300  and internal surface side  101   i  of housing  101  to secure airflow control system  300  to housing  101 . In some embodiments, adhesive  180  may be formed by cutting out an adhesive sheet such that adhesive  180  may include cut-out  182 . 
     In some embodiments, airflow control system  300  may be composed of plastic or a similar type of material, and thus, one or more of adhesives  180  and  190  may include any suitable type of adhesive that may adhere to plastic. In other embodiments, airflow control system  300  may be composed of metal or a similar type of material, and thus, one or more of adhesives  180  and  190  may include any suitable type of adhesive that may adhere to metal (e.g., solder). 
     It is to be understood that the steps shown in each one of processes  600  and  700  of  FIGS. 6 and 7 , respectively, are merely illustrative and that existing steps may be modified or omitted, additional steps may be added, and the order of certain steps may be altered. 
     The described embodiments of the invention are presented for the purpose of illustration and not of limitation.

Metadata:
Filing Date: 20120829
Publication Date: 20170228
Grant Date: 20170228
Priority Date: 20120829
Inventors: COHEN SAWYER
PORTER SCOTT
DAVE RUCHIR
Assignee: APPLE INC
CPC Classifications: [{"code": "B23K2101/42", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23K13/01", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K1/0016", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/4957", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/288", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/222", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K1/008", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/222", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K1/0016", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K2201/42", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/288", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23K13/01", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K1/008", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/4957", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 50187655