PATENT DOCUMENT

Publication Number: US-9829930-B2
Application Number: US-201313973467-A
Country: US
Kind Code: B2

Title: Portable computer electrical grounding and audio system architectures

Abstract:
A portable computing device having a substantially non-conducting outer housing and alternative electrical grounding and audio system architectures is disclosed. The device can be a laptop computer having a main logic board, a keyboard assembly, an audio source positioned below the keyboard assembly, and an equalizer electrically coupled to the audio source, with each of these components being electrically coupled to a universal grounding structure. The audio source emits sound waves that are propagated through the keyboard assembly and between gaps between keyboard keys and the outer housing. Settings for the equalizer can be selected to account for sound absorption and amplification characteristics of the sound waves along these sound transmission paths. The universal grounding structure includes a plurality of separate ground components that are electrically intercoupled, each being substantially smaller than the overall portable computing device, and also includes an electromagnetic interference shield around the main logic board.

Claims:
What is claimed is: 
     
       1. A portable electronic device, comprising:
 a housing defining apertures; 
 a keyboard assembly including keys, each of the keys extending through and filling a majority of a respective one of the apertures; and 
 an audio source positioned below the keyboard assembly and configured to emit sound waves,
 wherein substantially all of the sound waves emitted by the audio source travel through gaps between the keys and portions of the housing that define the apertures. 
 
 
     
     
       2. The portable electronic device defined in  claim 1 , wherein the audio source is configured to receive electrical signals and to generate the sound waves in response to the received electrical signals, the portable electronic device further comprising:
 an equalizer configured to compensate for absorption and amplification characteristics of the sound waves at the keyboard assembly by adjusting the electrical signals received by the audio source. 
 
     
     
       3. The portable electronic device defined in  claim 2 , wherein the equalizer is configured to increase a sound level of a first frequency sound wave emitted by the audio source and wherein the equalizer is configured to reduce a sound level of a second frequency sound wave emitted by the audio source. 
     
     
       4. The portable electronic device defined in  claim 2 , wherein the equalizer is configured to reduce a sound level of a sound wave emitted by the audio source at a frequency that produces an unwanted vibration in the housing. 
     
     
       5. The portable electronic device defined in  claim 1 , further comprising:
 a main logic board; and 
 an electromagnetic shielding structure for the main logic board, wherein the electromagnetic shielding structure forms a part of a universal grounding structure for the portable electronic device. 
 
     
     
       6. The portable electronic device defined in  claim 1 , further comprising:
 a main logic board; 
 an electromagnetic shielding structure around the main logic board; and 
 a conductive backplate structure that is electrically coupled to the main logic board, the keyboard assembly, and the audio source, wherein the main logic board is interposed between the conductive backplate structure and the electromagnetic shielding structure. 
 
     
     
       7. The portable electronic device defined in  claim 6 , wherein the conductive backplate structure and the electromagnetic shielding structure are electrically coupled via a plurality of conductive pins positioned through the main logic board. 
     
     
       8. The portable electronic device defined in  claim 1 , further comprising:
 a chamber acoustically coupled to the audio source, wherein dimensions of the chamber are selected to enhance a frequency response of one or more frequencies of the sound waves emitted from the audio source. 
 
     
     
       9. The portable electronic device defined in  claim 1 , further comprising:
 a keyboard assembly substrate interposed between the audio source and the portions of the housing that define the apertures. 
 
     
     
       10. A portable electronic device, comprising:
 a housing having an exterior surface defining a plurality of openings; 
 a keyboard assembly disposed within the housing and having a plurality of keys, wherein each key of the plurality of keys protrudes through and fills a majority of a respective opening of the plurality of openings; and 
 an audio source positioned below the keyboard assembly, wherein substantially all sound waves emitted by the audio source exit the housing through gaps between the plurality of keys and portions of the housing defining the respective openings. 
 
     
     
       11. The portable electronic device defined in  claim 10 , further comprising:
 a chamber acoustically coupled to the audio source, wherein the chamber has dimensions that are selected to enhance a frequency response of one or more frequencies of the sound waves emitted by the audio source. 
 
     
     
       12. The portable electronic device defined in  claim 10 , further comprising:
 an equalizer configured to compensate for sound wave absorption characteristics associated with emitting the sound waves through the keyboard assembly by increasing a sound level of a first frequency sound wave emitted by the audio source and decreasing a sound level of a second frequency sound wave emitted by the audio source.

Description:
This application is a continuation of U.S. patent application Ser. No. 12/580,985, filed Oct. 16, 2009, which is hereby incorporated by reference herein in its entirety. This application claims the benefit of and claims priority to U.S. patent application Ser. No. 12/580,985, filed Oct. 16, 2009. 
    
    
     CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to and incorporates by reference herein in their entireties the following commonly owned U.S. Patent Applications that were filed Oct. 16, 2009: 
     (i) U.S. patent application Ser. No. 12/580,922 entitled “COMPUTER HOUSING” by Raff et al., now U.S. Pat. No. 8,111,505; 
     (ii) U.S. patent application Ser. No. 12/580,914 entitled “PORTABLE COMPUTER DISPLAY HOUSING” by Bergeron et al., now U.S. Pat. No. 8,233,109; 
     (iii) U.S. patent application Ser. No. 12/580,946 entitled “PORTABLE COMPUTER HOUSING” by Casebolt et al.; 
     (iv) U.S. patent application Ser. No. 12/580,934 entitled “METHOD AND APPARATUS FOR POLISHING A CURVED EDGE” by Lancaster et al., which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application Ser. No. 61/249,200 entitled “COMPLEX GEOGRAPHICAL EDGE POLISHING” by Johannessen, filed Oct. 6, 2009, which is incorporated by reference herein in its entirety; 
     (v) U.S. patent application Ser. No. 12/580,881 entitled “SELF FIXTURING ASSEMBLY TECHNIQUES” by Thompson et al.; 
     (vi) U.S. patent application Ser. No. 12/580,976 entitled “BATTERY” by Coish et al., now U.S. Pat. No. 8,199,469, which is a continuation in part of U.S. patent application Ser. No. 12/549,570, filed Aug. 28, 2009, which is incorporated by reference herein in its entirety; 
     (vii) U.S. patent application Ser. No. 12/580,886 entitled “PORTABLE COMPUTER DISPLAY HOUSING” by Bergeron et al.; and 
     (viii) U.S. patent application Ser. No. 12/580,927 entitled “COMPUTER HOUSING” by Raff et al., now U.S. Pat. No. 8,199,468. 
     TECHNICAL FIELD 
     The present invention relates generally to portable computing devices, and more particularly to methods and systems for providing electrical grounding and audio system architectures in laptop computers. 
     BACKGROUND 
     The outward appearance of a portable computing device can be important to a user of the portable computing device. Design, heft, ease of portability, and overall aesthetic appearance are factors that many users consider when choosing a portable computing device for personal use. At the same time, the assembly and overall functionality of the portable computing device are also important to the user, since a durable assembly can extend the overall life of the device and thus increase its value to the user. Various factors that can be considered in the design of portable computing device components can include weight, strength, durability, cosmetic appearance, manufacturability, and thermal compatibility, among others. A component that is selected on the basis of its positive contribution to one of these design factors can have an adverse impact on one or more other factors. 
     One design challenge associated with the manufacture of portable computing devices is the design of the outer enclosures used to house the various internal computing components. This design challenge generally arises from a number conflicting design goals that include the desirability of making the outer enclosure or housing lighter and thinner, of making the enclosure stronger, and of making the enclosure aesthetically pleasing, among other possible goals. Lighter housings or enclosures tend to be more flexible and therefore have a greater propensity to buckle and bow, while stronger and more rigid enclosures tend to be thicker and carry more weight. Unfortunately, increased weight may lead to user dissatisfaction with respect to clunkiness or reduced portability, while bowing may damage internal parts or lead to other failures. Further, few consumers desire to own or use a device that is perceived to be ugly or unsightly. Due to such considerations, portable computing device enclosure materials are typically selected to provide sufficient structural rigidity while also meeting weight constraints, with any aesthetic appeal being worked into materials that meet these initial criteria. 
     As such, outer enclosures or housings for portable computing devices are often made from aluminum, steel and other inexpensive yet sturdy metals having a suitable thickness to achieve both goals of low weight and high structural rigidity. The use of metal enclosures is also convenient from the standpoint of providing a ready electrical ground and/or a ready radio frequency (“RF”) or electromagnetic interference (“EMI”) shield for the processor and other electrical components of the computing device, since a metal enclosure or outer housing can readily be used for such functions. In the event that alternative materials might be desired for such outer housings, however, such as for alternative aesthetic appearances and/or lighter overall devices, then various complexities may arise with respect to the traditional grounding and/or EMI shielding functions traditionally provided by a metal enclosure. 
     Further electrical issues may also require consideration where a traditional metallic outer housing or enclosure is not used for a laptop, netbook, tablet, or other portable computing device. For example, any desired RF transmissions to or from the portable computing device may require alternative antenna considerations, as well as additional electromagnetic or electrical shielding with respect to any processing components in the same device. In addition to raising various potential electrical issues, the use of a non-metallic or otherwise non-conducting outer housing or enclosure for a portable computing device might also present alternative issues with respect to other components, such as, for example, audio systems, visual display presentations, and input and output ports, among others. 
     While many designs and techniques used to provide enclosures for portable computing devices have generally worked well in the past, there is always a desire to provide further designs and techniques for alternative aesthetically pleasing yet mechanically strong and lightweight portable computing device housings. In addition, there is an accompanying desire to provide any alternative schemes or structures that might be desirable due to any deviations from traditional portable computing device housings, such as with respect to overall electrical system, EMI or RF shielding and/or audio system considerations. 
     SUMMARY 
     It is an advantage of the present invention to provide portable computing devices that are lightweight, strong, reliable, aesthetically pleasing and distinctive. Such portable computing devices can have outer housings that are comprised of entirely or predominantly plastic or other non-conducing materials, while still maintaining performance with respect to the overall electrical grounding and audio systems. This can be accomplished at least in part through the use of one or more alternative approaches for grounding the electrical components and for positioning the audio sources and other audio components within the portable computing devices. Effective audio system architectures can include positioning one or more audio sources beneath the keyboard assembly such that sound is directed through gaps between keys and/or the housing. Efficient grounding system architectures can include reduced grounding regions that also shield or isolate the main logic board from RF emissions or interference. 
     In various embodiments, a portable computing device has a substantially non-conducting outer housing and alternative electrical grounding and audio system architectures. The portable computing device can have a main logic board, a keyboard assembly, an audio source positioned below the keyboard assembly, and an equalizer electrically coupled to the audio source, with each of these components being electrically coupled to a universal grounding structure. The audio source can emit sound waves that are propagated through the keyboard assembly and between gaps between keyboard keys and the outer housing. Settings for the equalizer can be selected to account for sound absorption and amplification characteristics of the sound waves along these sound transmission paths. The universal grounding structure can include a plurality of separate ground components that are electrically intercoupled, with each being substantially smaller than the overall portable computing device. The plurality of separate ground components can include an electromagnetic interference shield around the main logic board, a rear bracket that physically couples a top cover to a lower body of the portable computing device, a metal backplate positioned proximate to the main logic board, and/or a plurality of conductive pins positioned through the main logic board and coupling the metal backplate with the electromagnetic interference shield. 
     In various general embodiments, a laptop computer or other portable computing device can include an outer housing, a main logic board located within the outer housing and having a primary processing unit coupled thereto, one or more additional electrically powered components located within the outer housing and separate from the main logic board, and a universal grounding structure having a plurality of separate ground components that are electrically intercoupled. The outer housing can be composed of entirely or predominantly one or more electrically non-conducting materials, such as a thermoplastic. The universal grounding structure can be electrically coupled to each of the main logic board and the one or more additional electrically powered components. Further, each of the separate ground components can be substantially smaller than the overall computing device, and at least one of the separate ground components can also provide an electromagnetic interference shield around the main logic board. 
     In some embodiments, the electromagnetic interference shield can comprise a metal Faraday cage of a size that is slightly larger than the main logic board. Further, one of the ground components can comprise a rear bracket that couples a top cover of the portable computing device to a lower body of the portable computing device and transmits physical loads therebetween. Still further, one of the ground components can comprise a metal backplate positioned such that the main logic board is between the metal backplate and the separate electromagnetic interference shield. In addition, the metal backplate can be electrically and mechanically coupled to the electromagnetic interference shield via a plurality of conductive pins positioned through the main logic board. 
     In various general embodiments, an audio system for a portable computer is described. The audio system is configured to direct sound from one or more audio sources positioned beneath a keyboard. An equalizer is applied to the audio sources to provide a more aesthetically pleasing sound quality. The equalizer settings are selected to account for sound amplification and sound absorption characteristics associated with the sound transmission paths related to the positioning of the audio source relative to the keyboard and the structural design of the keyboard assembly and its integration into the housing of the portable component device. 
     In various detailed embodiments, an audio system includes three audio sources, two piezoelectric speakers, and an electromagnetically driven cone type speaker. Each of the audio sources directs sound through gaps in a keyboard associated with the portable computer. In a particular embodiment, the cone type speaker is incorporated in a component that is also configured to hold and allow connections to a wireless card. The component includes a chamber that is designed to enhance certain frequencies emitted from the cone type speaker. 
     Other apparatuses, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The included drawings are for illustrative purposes and serve only to provide examples of possible structures and arrangements for the disclosed inventive apparatus and method for providing electrical grounding and audio system architectures in portable computing devices. These drawings in no way limit any changes in form and detail that may be made to the invention by one skilled in the art without departing from the spirit and scope of the invention. 
         FIG. 1  illustrates in right side front facing perspective view an exemplary portable computing device in an open state according to one embodiment of the present invention. 
         FIG. 2  illustrates in right side front facing perspective view the exemplary portable computing device of  FIG. 1  with audio signals being emitted from multiple audio sources via the keyboard according to one embodiment of the present invention. 
         FIG. 3  illustrates in side cross-sectional view an exemplary keyboard assembly having an audio source disposed therebeneath according to one embodiment of the present invention. 
         FIG. 4  provides a block diagram of an exemplary audio system according to one embodiment of the present invention. 
         FIG. 5  illustrates in side elevation view an exemplary inner component of the portable computing device configured to support a wireless card and an audio source according to one embodiment of the present invention. 
         FIG. 6  illustrates in top plan view the exemplary inner component mounted within a body of the portable computing device according to one embodiment of the present invention. 
         FIG. 7  illustrates in right side front facing perspective view an exemplary overall electrical grounding architecture for a partially disassembled portable computing device having a non-conductive outer housing according to one embodiment of the present invention. 
         FIG. 8A  illustrates in bottom plan view the body of the exemplary portable computing device of  FIG. 7  as partially disassembled according to one embodiment of the present invention. 
         FIG. 8B  illustrates in top plan view the body of the exemplary portable computing device of  FIG. 7  as partially disassembled according to one embodiment of the present invention. 
         FIG. 9  illustrates in close-up side cross-sectional view the rear bracket and surrounding region for the exemplary portable computing device of  FIG. 7  according to one embodiment of the present invention. 
         FIG. 10A  illustrates in front elevation view the lid of the exemplary portable computing device of  FIG. 7  according to one embodiment of the present invention. 
         FIG. 10B  illustrates in side cross-sectional view the lid of the exemplary portable computing device of  FIG. 7  according to one embodiment of the present invention. 
         FIG. 10C  illustrates in close-up side cross-sectional view the display clutch assembly for the exemplary portable computing device of  FIG. 7  according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary applications of apparatuses and methods according to the present invention are described in this section. These examples are being provided solely to add context and aid in the understanding of the invention. It will thus be apparent to one skilled in the art that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the present invention. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments of the present invention. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the invention, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the invention. 
     The invention relates in various embodiments to a portable computing device such as a laptop computer, netbook computer, tablet computer, and the like. The portable computing device can have an outer housing formed from entirely or substantially from a non-electrically conducting material, such as a thermoplastic. In some embodiments, alternative audio system architectures can include positioning one or more audio sources beneath the keyboard assembly such that sound is directed through gaps between keys and/or the housing. In some embodiments, efficient grounding system architectures can include reduced grounding regions that also shield or isolate the main logic board from RF and/or other electromagnetic emissions or interference. These general subjects are set forth in greater detail below, starting with the outer housing, continuing to the audio system, and finishing with the electrical grounding system, as well as methods therefor. 
     Outer Housing 
     The following relates to a multi-part housing suitable for a portable computing device such as a laptop computer, netbook computer, tablet computer, and the like. The multi-part housing can include a structural support layer. The structural support layer can be formed of a strong and durable yet lightweight material. Such materials can include composite materials and/or metals such as aluminum. Aluminum has a number of characteristics that make it a good choice for the structural support layer. For example, aluminum is a good electrical conductor that can provide good chassis ground and it can be easily machined and has well known metallurgical characteristics. Furthermore, aluminum is non-reactive and non-magnetic which can be an essential requirement if the portable computer has RF capabilities, such as WiFi, AM/FM, and the like. In order to both protect the structural support layer and provide an aesthetically appealing finish (both visual and tactile), a protective layer can be placed on an external surface of the structural support layer. The protective layer can extend up and around an edge of the structural support layer to both enhance the aesthetic appeal of the housing and to protect the appearance of the portable computer. The protective layer can be formed of, for example, Thermoplastic Polyurethane (“TPU”). 
     The multi-part housing can also include a body suitable for enclosing a computer assembly. The body can, in turn, include a cosmetic outer layer supported by an inner layer that can both transfer and distribute loads applied to the portable computing device. The outer layer can be formed of lightweight yet durable materials. Such materials can include, for example, blends of poly-carbonate and acrylonitrile butadiene styrene (“ABS” or “PCABS”) that exhibit high flow, toughness and heat resistance well suited for portable applications. The inner layer can be formed of metal such as magnesium or magnesium alloy. The inner layer can be connected directly to the structural support layer forming a load path between the inner layer and the structural support layer. In this way, a load applied to the portable computing device can be distributed across the inner layer and transferred along the load path to the structural support layer without substantially affecting the cosmetic outer layer. Since the cosmetic outer layer does not have to be load tolerant, the cosmetic outer layer can be formed of flexible, but aesthetically pleasing materials such as lightweight plastic that would otherwise be unsuitable for use with a conventional portable computer housing. In the embodiments where the inner layer is metallic or at least electrically conductive, the inner layer and the structural support layer can, taken together, provide a suitable electrical ground plane or chassis ground. This can be especially important due to the fact that by selecting a plastic or other non-conducting material for the cosmetic outer layer, the cosmetic outer layer cannot provide a suitable ground. Moreover, due to the close proximity of the operational components to one another in the portable computing device, it is highly desirable to isolate sources of significant RF radiation, such as a main logic board (“MLB”), from those circuits, such as wireless circuits, that can be highly sensitive to RF interference. In this way, the inner layer can include a metal frame that can, in combination with the structural support layer, be used to electromagnetically isolate the MLB from other components in the computer assembly sensitive to RF interference such as a WiFi circuit. 
     Since the cosmetic outer layer is essentially load isolated, the choice of materials that can be used to form the cosmetic outer layer can be widely varied. In this way, a product designer can create a look and feel for the portable computer well beyond anything realistically possible with a conventional computer housing. For example, the cosmetic outer layer can be formed of lightweight thermoplastic and molded into any shape (such as an undercut shape). Since the cosmetic outer layer does not provide much, if any, structural support for the portable computer, the shape of cosmetic outer layer can also be widely varied. For example, the cosmetic outer layer can present a continuous spline profile so as to appear to an observer to be a single unified shape with substantially no discontinuities. Moreover, since there is no need for external fasteners that would detract from the overall appearance of the portable laptop computer, the overall look and feel presented by the cosmetic outer layer can be one of a simple continuous shape. 
     Again, since the cosmetic outer layer does not carry substantially any loads, the cosmetic outer layer can include a number of openings having wide spans that do not require additional support structures. Such openings can take the form of ports that can be used to provide access to internal circuits. The ports can include, for example, data ports suitable for accommodating cables (USB, Ethernet, FireWire, etc.) connecting external circuits. The openings can also provide access to an audio circuit, video display circuit, power input, and the like. 
     The portable computer can also include a movable cover. The movable cover can include an inner frame supporting a cosmetic outer layer. The inner frame can in much the same way as the inner layer of the body, distribute and transfer a load applied to the movable cover. In the described embodiments, the inner frame can be formed of materials that are strong, lightweight and electrically conductive. Such materials can include, for example, aluminum, magnesium and/or magnesium alloys. By connecting the inner frame to the inner layer of the body, the inner frame can become part of the load path to the structural support layer. In this way, any load applied to the movable cover can be distributed across the inner frame and transferred to the structural support layer by way of the inner layer of the housing. For example, the movable cover can take the form of a lid that can be opened to reveal a portion of the body and closed to hide the portion of the body. By connecting the inner frame to the inner layer of the body using connectors, such as hinges, the inner frame can become part of the load path. In this way, a load imparted to the lid such as when the lid is opened (or closed), for example, can be transferred along the load path from the lid to the structural support layer. 
     The structural support layer can be mechanically connected to the body inner layer by way of any number and type of fasteners. Such fasteners can include screws, rivets, and the like. In this way, the inner layer and the structural support layer can become essentially a single unit. The body can be thought of as having a front portion and a rear portion depending upon, for example, the expected operational orientation of the portable computer. For example, if the portable computer is a laptop that has a touch or track pad, then that portion of the body that includes the touch pad can be considered to be the front portion (as viewed by a user when actually using the laptop), and conversely, a keyboard can be considered to be part of the rear portion. Since the cosmetic outer layer is typically formed of flexible material, such as plastic, that is easily bent and deformed, the flexibility inherent in the choice of material for the body must be substantially reduced or eliminated in the finished product in order to protect internal components, such as a main logic board, or MLB, that could be damaged by such flexing. 
     Certain of the operational components installed within the body can each function both as an operational component as well as a structural support component. However, these dual purpose components are limited to those components that in and of themselves are structurally resistant to flexion. Such components can include, for example, an enhanced load bearing battery, a hard disc drive (“HDD”), an optical disc drive (“ODD”), a touch pad support, and so forth. Accordingly, these dual purpose components can be located in the front portion of the body consistent with the location of the touch pad, for example. In order to mount these components into the body, support features can be attached directly to an interior surface of the cosmetic outer layer using, for example, glue or other appropriate adhesive. The support features can then be used to mount the dual purpose operational components into the body during an assembly operation. For example, dual purpose operational components can be installed using metal pin adapters that can be inserted into corresponding metal bosses formed in an appropriate structural component glued to the interior surface of the cosmetic outer layer. In this way, there are no plastic bosses into which metal screws are attached thereby greatly enhancing long term structural integrity of the computer housing. 
     The rear portion of the body can include a frame formed of metal such as for example, magnesium or magnesium alloy mounted to an upper inside surface (onto which the keyboard is mounted) of the cosmetic layer. The metal frame can be used to support those components, such as the MLB, that cannot be used to provide additional support for the body. The metal frame can also provide a local ground plane as well as to help distribute as well as transfer loads applied to the portable computing device at either the display or the body itself. In one embodiment, the metal frame can be shaped to include a spanning portion used to transfer loads around the openings in the cosmetic outer layer. In this way, the openings can have wide spans without the need for additional support at the cosmetic outer layer. The rear portion of the body can also include a rear bracket. The rear bracket can connect directly to the structural support layer as part of the load path. The rear bracket can also include venting features along the lines of a baffle suitable for allowing the passage of air between the operational components within the body and the external environment. The rear bracket can be formed of metal such as magnesium having a number of attachment features that can be used to attach the rear bracket to the structural support layer to form the load path. The rear bracket can also include attachment features allowing additional portions of the portable computer, such as a cover having a display, to become part of the load path. For example, at least one attachment feature can be coupled to a hinge assembly that allows a user to open and or close the cover where any loads generated are transferred to the structural support layer by way of the load path. 
     Audio System Architecture 
     More specific examples, particularly with respect to alternative audio system architectures, will now be provided. Referring first to  FIG. 1 , an exemplary portable computing device in an open state is illustrated in right side front facing perspective view. Portable computing device  200  can include body  202  and lid  204  having display  206 . Lid  204  can be moved by a user from a closed position to an open position as shown. Display  206  can display visual content such as a graphical user interface, still images such as photos as well as video media items such as movies. Display  206  can display images using any appropriate technology such as a liquid crystal display (“LCD”), organic LCD (“OLCD”) and the like. Portable computing device  200  can also include image capture device  208  located on lid  204 . Image capture device  208  can be configured to capture both still and video images. Compliant display trim  210  formed of suitable compliant material can be supported by structural components (not shown) within lid  204  but attached to cosmetic cover  211  of lid  206 . Not attaching compliant display trim  210  directly to a structural component provides for good registration between the cosmetic rear cover  211  of lid  206  and compliant display trim  210 . Display trim  210  can enhance the overall appearance of display  204  by hiding operational and structural components as well as focusing a user&#39;s attention onto the active area of display  206 . Lid  204  can be coupled to body  202  using a hinge assembly (hidden by clutch barrel  213 ) that in turn can be connected by way of a load path to structural support layer  212 . Structural support layer  212  can be formed of composite material or metal such as aluminum. Structural support layer  212  can be covered by protective layer  214  formed of protective yet durable material that is both attractive to the eye and the touch. Protective layer  214  can be formed of TPU that extends up and over an edge of structural support layer  212  to form a seal with body  202 . The seal providing both protection from contaminants from the external environment as well as an appearance of continuity in the shape of body  202 . 
     Body  202  can include a number of user input devices such as touch pad  216  and keyboard  218 . Keyboard  218  can include a plurality of key pads  220  each having a symbol imprinted thereon for identifying to a user the key input associated with the particular key pad. Keyboard  218  can be arranged to receive a discrete user input at each keypad using a finger motion referred to as a keystroke. In the described embodiment, the symbols on each key pad can be laser etched thereby creating an extremely clean and durable imprint that will not fade under the constant application of keystrokes over the life of the portable computing device  200 . Touch pad  216  can be configured to receive a user&#39;s finger gesturing. A finger gesture can include touch events from more than one finger applied in unison. The gesture can also include a single finger touch event such as a swipe or a tap. 
     Body  202  can also include power button  222  arranged to assist the user in turning on and turning off portable computing device  200 . Audio input device  224  can be used as a microphone to receive audible input such as speech. Status indicator light (SIL)  226  can be used to provide a user with information. Such information can be related to, for example, an operational status of portable computing device  200 . Since body  202  can be formed of semi-translucent plastic material that can transmit a noticeable portion of light (referred to as light bleed), SIL  226  can be configured to substantially eliminate all light except that confined by the geometric confines of SIL  226 . Body  202  can also include openings used for accessing operational circuits mounted within housing  202 . For example, disc slot  228  can be used for inserting disc media such as compact discs (CDs) and or digital versatile discs (DVDs). 
     As a convention, body  202  can be considered to be divided into front portion  230  and rear portion  232  as viewed by a user when operation portable computing device. In this way, touch pad  216  can be considered to be located in front portion  230  and keyboard  218  can be considered to be located in rear portion  232 . The significance of the location of touch pad  216  and keyboard  218  will be discussed in more detail below with regards to the configuration of a inner layer of body  202 . 
     Continuing now with  FIG. 2 , the exemplary portable computing device of  FIG. 1  is shown in right side front facing perspective view with audio signals being emitted from multiple audio sources via the keyboard. To provide audio signals to a user, such as music and sounds, associated with various applications that can be executed on the portable computing device, one or more audio sources can be provided. The one or more audio sources can be located within the body  202 . Three audio sources emitting audio signals  350  are shown in the  FIG. 2  for purposes of illustration, although it will be readily appreciated that more or fewer audio sources may be used, as desired. 
     In one embodiment, the gaps between the keys of keyboard  218 , including various keys such as key  352 , allow audio signals generated within the body  202  to be propagated away from the portable computing device  202 . In other embodiments, other apertures in the body  202  can be used to provide an audio propagation path from the interior of the body to the exterior. For example, as is described with respect to  FIG. 6  below, vents used for air cooling of the processor can also be used to propagate audio signals from the interior of the body  202 . 
     One advantage of using the gaps between the keys of the keyboard  218  as a path for propagating audio signals can be that additional apertures do not have to be added to the body  202  for the purposes of sound propagation. The removal of dedicated apertures for sound propagation purposes can provide a design that is considered more aesthetically pleasing. In addition, manufacturing costs can be reduced since the machining of body  202  is reduced. Further, the removal of the dedicated apertures can eliminate potential entry points for dust and liquid that can adversely affect the electrical components housed within the body  202 . 
       FIG. 3  is a cross section of an exemplary keyboard assembly  378  with an audio source disposed below the key board assembly. The figure includes a key  368  mounted to a support structure  376  that is attached to the keyboard substrate  378 . The key  368  can be actuated towards the keyboard substrate by applying a force to the top surface of the key  368 . An aperture slightly larger than the key  368  is provided in an outer layer  366  of the body  202  to accommodate actuation of the key  368 . 
     In one embodiment, an audio source  310  can be disposed below the keyboard assembly substrate  378 . The audio source  310  is shown located in substrate  382  for the purposes of illustration and is not limited to this location. For instance, in one embodiment, the audio source  310  can be integrated into the keyboard assembly, such as integrated into or mounted on top of the substrate  378  rather than in a separate component as shown in  FIG. 3 . Further, an audio source can be located below various keys in the keyboard  218  and is not limited to a particular key location. 
     In one embodiment, an audio source is positioned proximately below the ‘F 6 ’ key on the keyboard, but is not limited to this location. It can be desirable to locate the audio source below a key that is not frequently used, such as a key on the periphery of the keyboard to avoid absorption of sound by the hands of a user utilizing the keyboard. For instance, when an audio source is located near the top of the keyboard, such as below a function key, the hands of a user are typically below this position during normal operation. 
     When the audio source  310  is mounted below the keyboard assembly, the substrate  378  of the keyboard assembly can include an aperture  380  located above the audio source to provide an audio transmission path for the audio signals generated by the audio source through the keyboard substrate  380 . The audio signals refer to the sound waves generated by the audio source, such as  310 . In various embodiments, one or more apertures through the keyboard substrate  380  can be provided, such as a number of small apertures or a single large aperture. 
     In a particular embodiment, a chamber of air  308 , such as a tube, can be connected to the audio source  310  to enhance (e.g., amplify) one or more audio signal frequencies emitted from the audio source  310 . One end of the chamber can receive audio signals generated from the audio source where propagation of the audio signals through the chamber can enhance one or more audio signal frequencies, such as by producing harmonics. The size and dimensions of the chamber  308  can be selected to produce a desired enhancement to the frequency response of the audio source  310 . In one embodiment, the chamber  308  is sized to enhance lower audio signal frequencies in the frequency response of audio source  310 . In various embodiments, audio sources  310  with or without one or more chambers configured to alter a frequency response of the audio source can be utilized. 
     The chamber  308  includes an exit port  370 . The exit port  370  can include a cover, such as a mesh cover, that can alter the audio signals emitted from chamber  308 . The driver for the audio source  310  is shown in a configuration where the primary direction  384  of the emitted audio signals (sound waves of various frequencies) is towards the bottom of the key  368 . The exit port  370  is shown in an orientation where the primary direction of the emitted sound waves is in a direction that is perpendicular to that of the driver of the audio source  310 . 
     In general, the primary directions of the emitted audio source and exit port  370  of chamber  308  can be directed to take advantage of any audio transmission paths that can result from or lend themselves to the packaging of the various internal components of the portable computing device and are not limited to a location below the keyboard. For instance, in one embodiment, the primary direction of the audio source  310  is through the keyboard  218  while the exit port associated with chamber  308  is aligned with vents used to provide air circulation and cooling to the main logic board located on a side of the body  202 . In addition one or more audio sources can be located in the movable portion of the portable computing device  200  including the display. 
     In yet other embodiments, an audio source, such as  310 , can be coupled to a chamber with an exit port  370 . The primary directions of the audio signals emitted from the driver of the audio source  310  and the exit port  370  can be selected to take advantage of desired audio transmission paths and can be orientated any configuration relative to one another. As examples, the exit port  370  can be aligned such that emits audio signals in generally the same direction as the driver of the audio source  310 , it can be orientated so that it primarily emits audio signals in an opposite direction (e.g., away from key  368 ), or the exit port  370  (as shown) can direct audio signals in a direction perpendicular to the audio source  310 . 
     In  FIG. 3 , a primary direction  384  of the audio signals emitted from the driver of the audio source  310  is parallel to the alignment of gap  364  and perpendicular to a top surface of the driver of the audio source  310  and a top surface of the key  368 . In other embodiments, the primary direction  384  can be in other directions. For example, the driver for the audio source  310  can be tilted such that the primary direction  384  of the audio source is no longer parallel to the direction of the gap  364 . In particular, the primary direction  384  can be tilted toward the touch  216  (as shown in  FIG. 2 ) to potentially direct more sound to a user of the portable computing device. 
     In  FIG. 3 , after audio signals or sound waves are emitted from audio source  310 , the sound waves can propagate through various paths within the body  202  of the portable computing device. For instance, sound waves can propagate along paths from the driver of audio source  310 , through the gap  372  between the substrate  384  of the audio device  310  and the substrate  378  of the keyboard assembly, through one or more apertures  380  in the substrate  278  of the keyboard assembly, through a gap  374  between the substrate  380  of the keyboard assembly and the outer layer  366  of the body  202  and exit the body  202  between gaps, such as  364  between a key, such as  368 , and the outer layer  366  of the body. Some sound waves emitted from the audio source can be absorbed and/or reflected as they propagate from audio source  310  through the interior of the body  202  to the exterior of the body  202  increasing/or decreasing sound levels for certain frequencies emitted from the audio source  310 . Further, various harmonics of the sound waves may be created. These harmonics can potentially cause unwanted vibrations or noises. 
     The amount that a particular sound wave is affected during its propagation through the body  202  can depend on the frequency of the wave, material properties of various components along its transmission path, such as how much sound energy various materials absorb or reflect as a function of frequency, spacing between layers, such as gaps  372  and  374 , spacing between the keys, such as  364  and an outer layer  366  of the housing and the key  368  and a size and number of apertures in substrate  378 . Thus, a frequency response of audio source  310  that is measured in a free standing configuration when it is not installed in the body  202  can be quite different than a frequency response of the audio source  310  measured at some point above the keyboard  218  when it is installed within the body  202 . 
     In some embodiments, an equalizer can be applied to the electrical signals sent to the driver of the audio source,  310 , installed within the body  202  of the portable computing device  200  to improve the sound quality detected outside of the body from the audio source  310 , such as the sound quality detected by a user of the portable computing device. The equalizer can be applied such that the frequency response of audio source  310  is altered. The application of the equalizer can result in certain frequencies being increased in amplitude and other frequencies being decreased when sounds, such as music, are output via the audio source  310 . 
     Turning next to  FIG. 4 , a block diagram of an exemplary audio system according to one embodiment of the present invention is provided. Audio system  390  can include one or more audio sources, such as  391 , and audio signal processing  360  including equalizer  362 . The audio source can be a loudspeaker that includes one or more electroacoustic transducers that convert electric signals into sound waves that are propagated through a medium such as air. The transducer portion of a loudspeaker can be referred to as a driver. A conical diaphragm driven by an electromagnetic interaction and a piezoelectric material that vibrates in response to an application of electricity are two examples of types of transducers that can be utilized with the audio system  390  described herein. The audio signal processing  360  can refer to various combinations of hardware and/or software that transform audio data encoded in a particular format, such as a digital format, to an electrical signal that is compatible with a particular design of an audio source, such as  310 , used with the portable computing device. 
     At some point in the conversion of the audio data encoded in a particular format to the signal received by the audio source, the equalizer  362  can be applied such that the electrical signal sent to the audio source is altered. The equalizer  362  can be applied to produce a more aesthetically pleasing sound quality from the audio source, such as  391 , when it is detected outside of the body  202  of the portable computing device. Also, some equalizer  362  functions can be applied to reduce unwanted vibrations and buzzing noises that can result from normal operation of an audio source. Different equalizers can be used for different audio sources to account for the frequency response of the audio source as well as its associated sound transmission paths that can be unique to the location where the audio source is installed in the body  202 . 
     In other embodiments, different equalizers can be used for different audio data, such as music or a type of music. In a particular embodiment, the type of audio data that is being output can be detected and an equalizer associated with an audio source can be adjusted to account for the type of audio data. In another embodiment, the equalizer, such as  362 , for a particular audio source can be dynamically adjusted depending on whether it is determined whether the keyboard is being actively used or not. The placement of the hands of a user over the keyboard can alter detected sound quality from an audio source transmitted through the speaker. Further, the transmission of sound through the keyboard can produce tactile sensations in the keyboard that can be undesirable to a particular user. Thus, it can be desirable to alter the equalizer, such  362 , for a particular audio source, such as  391 , transmitting through the keyboard when the keyboard is being actively used. 
       FIG. 5  is a diagram of an inner component  302  of the portable computing device  200  configured to support a wireless card (not shown) and an audio source  310 . The component  302  can be formed from a material such as plastic. In particular embodiment, the inner component  302  includes two attachment points  316   a  and  316   b  that allow a fastener, such as screw to be inserted. A bottom surface of the component is indicated by surface  314 . The bottom surface  314  can be cut out  311  to allow for connections to a wireless card inserted on the top side of component  302  opposite the bottom surface  314 . A cut out  311  allowing for three connections is shown in  FIG. 5 . The bottom surface includes an addition cut out  312   a  through the surface  314  and a slot  312   b  in surface  314 . 
     The slot  312   b  provides a path for ribbon cable and the cutout  312   a  allows the ribbon cable to be attached to the wireless card. The component  302  includes a loudspeaker  310 . In a particular embodiment, the loudspeaker includes a cone type driver driven by an electromagnetic interaction. A chamber  308  with an exit port  306  is acoustically connected to speaker  310 . The chamber  308  can be sized to enhance a frequency response of the speaker  310 , such as a lower frequency response. In this embodiment, the size of the chamber  308  is limited by the placement of the wireless card. The placement of the wireless card limits a potential length of the chamber  308 , i.e., the distance from the speaker to the exit port  306 . The tube  308  is not necessarily rectangular and can be curved shaped in some embodiments. 
     Moving next to  FIG. 6 , an exemplary inner component  302  mounted within a portion  301  of body  202  of the portable computing device  200  is illustrated in top plan view. In this diagram, a lower cover of the body  202  is removed. The opposite side of the body  202  includes apertures for allowing the keys of a keyboard assembly to be actuated. The component  302  is shown in an installed position within the portion  301 . The component is positioned next to a structural stiffener  330 . 
     The component  302  is positioned such that the speaker  310  directs sound through the keyboard on the opposite side. In one embodiment, as described above, the speaker can be positioned below the ‘F 6 ’ key of the keyboard. The exit port  306  is positioned such that sound from chamber  308  is directed toward a backside  332  of the portion  301 . The backside is where the body  202  and a display portion of the portable computing device are coupled together via hinge and can include ports for providing air circulation for cooling of the portable cooling device. The sound from the chamber  308  can be directed out one of more these ports. 
     A wireless card  324  is shown inserted in the component  302  in  FIG. 6 . The two connectors  326   a  and  326   b  are shown connected to the wireless card  324 . A ribbon line connector  322  is also shown connected to the wireless card  324  and the main logic board  303 . Two additional speakers  304   a  and  304   b  are shown attached to the portion  301  of the body  202 . In one embodiment, the speakers  304   a  and  304   b  can be piezoelectric speakers. In a particular embodiment, the speakers  304   a  and  304   b  can also be positioned to direct sounds through the keyboard on the opposite side. In this configuration, speakers  310 ,  304   a  and  304   b  may not be visible when a user is looking at the keyboard. Again, it will be understood that more or fewer speakers may be used, some of all or which are similarly positioned beneath the keyboard. 
     Electrical Grounding System Architecture 
     Specific examples with respect to alternative electrical grounding architectures will now be provided. In particular, the following alternative electrical grounding structures can prove to be particularly useful for portable computing devices that employ outer housings that are not electrically conductive. Again, such portable computing devices can include, for example, a laptop computer, netbook computer, tablet computer, and the like. It will be understood that the following alternative electrical grounding structures can be utilized separate from or in addition to the various audio system architectural components set forth in greater detail above. In some arrangements, one or more components can provide functionalities with respect to both of the electrical grounding and audio system architectures. 
     In general, the provided examples can avoid the traditional method of employing the entire enclosure or outer housing as a total Faraday shield and/or ground plane for the portable computing device. This is particularly useful where the enclosure or outer housing is composed entirely or predominantly of a thermoplastic or other non electrically conducting material. Instead, a plurality of localized and smaller grounding regions and EMI/RF shields can be applied within the portable computing device. These smaller localized grounding regions can be electrically intercoupled with each other to form an overall ground plane or universal grounding structure for the entire device. Further, one or more of these localized grounding regions and/or the electrical couplers therebetween can also provide one or more additional functions for the portable computing device, such as structural supports, hinges, brackets, and clutches, among other possibilities. 
     Turning now to  FIG. 7 , an exemplary overall electrical grounding architecture for a partially disassembled portable computing device having a non-conductive outer housing is illustrated in right side front facing perspective view. Portable computing device  200  can be, for example, a laptop computer, and can again include a body  202  and movable lid  204  having a display  206 . Numerous additional features and components of portable computing device  200  are set forth in greater detail above, and will not be discussed further unless relevant to the electrical grounding system architecture. Some components of computing device  200  have been removed from  FIG. 7  for purposes of illustration, including the keyboard, touchpad and display screen, among others. Universal grounding structure  400  provides an overall ground plane for portable computing device  200 , which overall ground plane can be comprised of a plurality of separate ground components  401 . These separate ground components  401  can be localized to different regions of the portable computing device, and can be electrically intercoupled by various electrical connectors, such that a universal ground plane for the entire device is created. 
     Separate ground components comprising localized ground regions can include, for example, backplate  410 , MLB frame  420 , rear bracket  430 , and display chassis  440 . Electrical connectors that can be used to couple these various localized and separate ground components to form an overall device ground plane can include, for example, MLB  403 , a plurality of grounding pins  415 , a plurality of rear bracket tabs  435 , display chassis wiring  445 , and a ribbon line connector  424  coupled to a sound component  402  that is in turn coupled to a display clutch assembly  450 . It will be readily appreciated that additional or fewer separate ground components may exist or be designated as part of universal grounding structure  400 , and that various electrical connectors, such as any of the foregoing exemplary electrical connectors, may be resized, rearranged or otherwise designated as separate ground components themselves within the universal grounding structure. Similarly, additional or fewer electrical connectors may be used to intercouple the various localized separate ground components of universal grounding structure  400 . 
     One benefit that can be realized by having multiple localized grounding regions rather than a traditional single ground plane comprising a conductive outer housing is that appropriate focus can be applied with respect to the grounding needs of particular components, such that material costs may be reduced. Such reductions can be enhanced by utilizing one or more already existing components that provide other functions as part of the universal grounding structure  400 . While this may result in some design alterations and/or extensions of certain components, the overall need to resort to added metal or other conductive structures just to provide a universal ground plane is reduced or eliminated. Notably, various smaller localized ground regions are created, with none of these regions being so traditionally large as the entire enclosure or outer housing. 
     Moving next to  FIGS. 8A and 8B , the body of the exemplary portable computing device of  FIG. 7  is shown as being partially disassembled in bottom plan and top plan views respectively. Further details of the various separate ground components, electrical connectors and other device components can be seen with the bottom housing removed in  FIG. 8A  and the keyboard, touchpad and upper housing removed in  FIG. 8B . For purposes of illustration, the bottom of the outer housing has been removed in  FIG. 8A  to reveal various components internal to body  202 . As such, the bottom outer housing portion and coupled backplate  410  are not shown in  FIG. 8A . It will be understood that backplate  410  exists at about the level of the page of this figure, as  FIG. 8A  is looking into the body  202  from the bottom of device  200 . As shown, portable computing device  200  can have a number of typical electrical components, such as a main logic board (“MLB”)  403 , battery assembly  404 , hard disc drive (“HDD”)  405 , fan  406 , optical disc drive (“ODD”)  407 , and sound component  402 , among others. It will be readily appreciated that some components can provide load bearing as well as electrical ground bearing capabilities. 
     As noted above, some of the localized separate grounding components and/or the electrical couplers therebetween can provide additional functions for the portable computing device, such that space constraints are minimized, excess metal is not applied solely for the sake of providing a ground plane, and overall device components are reduced and streamlined. For example, backplate  410  is a localized separate ground component that forms part of universal grounding structure  400 , and can also serve as an inner structural component to which outer housing  201  can attach and be supported. As noted previously, outer housing  201  can comprise any of a wide variety of non-conducting materials having any of a wide variety of appearances and textures under the present invention, such as a thermoplastic, for example. As such, backplate  410  can provide structural support and rigidity for a potentially structurally unreliable outer housing  201 . Thus, backplate  410  may serve as the structural support layer noted in the “Outer Housing” section above. To meet all of the foregoing functional requirements, backplate  410  can be comprised of a suitable metal, such as aluminum, steel, magnesium or a magnesium alloy, for example. 
     MLB frame  420  provides another example of a localized separate ground component that provides multiple functions for portable computing device  200 . That is, in addition to providing a localized separate ground component for electrical items such as MLB  403 , fan  406 , and numerous electrical components on or coupled to MLB  403 , MLB frame  420  also provides support and structural rigidity for MLB  403 . Due to the potentially large number of individual components on MLB  403  that are surface mounted or are otherwise susceptible to being damaged by flexion, MLB  403  must be firmly supported. MLB frame can be specifically designed to perform such a support function. Other components that can be mounted to and physically supported by MLB frame  420  can include fan  406 , optical disc drive  407 , and sound component  402 , among others. As noted above, sound component  402  can comprise an integrated audio/wireless card that is electrically connected to MLB  403  and also to MLB frame  420  by way of a flex or ribbon line connector  424 . Such a connection to MLB frame  420  can be made at a grounding point  425  where a midsection of flex or ribbon line connector  424  contacts a wall edge of the MLB frame, for example. Additional components that MLB  420  may provide grounding for include any number of I/O ports that may be coupled to MLB  403 . 
     As yet another function, MLB frame  420  can also provide RF or EMI shielding for MLB  403 . Such an RF or EMI shield can effectively result from a combination of MLB frame  420  and backplate  410 , since MLB frame  420  may not surround MLB  403  in all directions. In some embodiments, MLB frame  420  and backplate  410  may combine to serve as a localized Faraday cage for MLB  403 , although the MLB frame and backplate combination preferably at least provides an EMI shield to insulate any noise between the MLB and one or more other components located elsewhere on portable computing device  200 . In particular, the RF shielding aspects of MLB frame  420  and/or backplate  410  can shield noise or interference between the MLB  403  and any wireless antennae in the portable computing device  200 , such as antennae that may be embedded in the display housing and/or display clutch assembly, for example. Electrical connectors between MLB frame  420  and backplate  410 , such as grounding pins  415 , may further enhance the combined universal ground plane and/or EMI shielding properties of these components. 
     MLB frame  420  can be formed from a strong, rigid, lightweight, and electrically conductive material, such as aluminum, magnesium or a magnesium alloy, among other suitable choices. In some embodiments, a magnesium alloy is used. As noted, MLB frame  420  can provide structural support and rigidity for various components that do not tolerate much flexion, such as MLB  403 . MLB frame  420  can also distribute loads received from one or more load bearing components, such as by way of various structural connectors. In some embodiments, MLB frame  420  can be configured to provide support to external features fabricated in the non-conducting outer housing. For example, various openings in the outer housing can be used to provide access to data ports, power ports and so on, some of which may be required to have relatively large spans. 
     In some embodiments, MLB frame  420  can form five sides of a rectangular box, with the MLB  403  being disposed therein, and the open sixth side being covered by backplate  410  after assembly. In some embodiments, MLB frame  420  can be sized such that it is only slightly larger than the MLB  403 , such that excess material is not wasted. This can result in savings on the cost and weight of MLB frame  420 , and portable computing device  200  overall. In some embodiments, MLB frame  420  may be integrally formed with one or more extensions that are used to provide structural support and/or electrical grounding for one or more other electrical components within portable computing device  200 . For example, a lateral extension of MLB frame  420  can extend from MLB  403  across and above ODD  407  and to the opposing sidewall of the outer housing of body  202 . Such a lateral extension may also include holes, and a middle wall may exist within MLB frame  420  between the MLB  403  and the ODD  407 , such as for added separation and support. 
     The weight of preferably lightweight MLB frame  420  can be further reduced by forming a plurality of holes  422  therethrough by using any of a number of suitable techniques, such as stamping. The plurality of holes  422  can reduce the weight of MLB frame  420  without substantially affecting its strength or its ability to provide support for components that have little or no tolerance for flex, such as MLB  403 . In addition, the plurality of holes  422  can be arranged in a particular pattern such that EMI shielding is maximized despite the removal of a significant amount of material from MLB frame  420 . Such hole creation or material removal patterns that results in a reliable EMI shield will be readily appreciated by those skilled in the art, and any such suitable pattern may be used for the holes  422  on MLB frame  420 . 
     As noted above, a variety of electrical connectors can be used to couple electrically separate ground components, such as backplate  410  and MLB frame  420 . For example, MLB  403  and or a plurality of grounding pins  415  can be utilized to electrically intercouple backplate  410  and MLB frame  420 . Of course, other electrical connectors can be used for the same purpose, and alternative indirect paths may also result in an electrical coupling of backplate  410  and MLB frame  420  as part of the general formation of a universal grounding structure  400 . Further electrical connectors can be used to connect backplate  410  and/or MLB frame  420  to one or more other localized separate ground components, such a rear bracket  430  and/or display chassis  440 . For example, a plurality of rear bracket tabs  435  can electrically couple rear bracket  430  to MLB frame  420 , while display chassis wiring  445  can couple display chassis  440  to rear bracket  430 , such as via a display clutch assembly  450 . In addition, a ribbon line connector  424  coupled to a sound component  402  that is in turn coupled to the display clutch assembly  450  can electrically connect the MLB frame  420  to the display chassis wiring  445  and thus the display chassis  440 . 
     In some embodiments, the integrated wireless/audio card comprising sound component  402  might not be mounted directly to MLB frame  420 , but rather can rest on a metal platform or wing that is part of ODD  407 , which can be used to accommodate optical media, for example. In addition to providing support, the metal platform can provide a chassis ground to which display chassis wiring  445  can be connected. As noted previously, grounding pins  415  can be used to make electrical contact between MLB frame  420  and backplate  410 , such as through MLB  403 . Grounding pins  415  may serve as direct contacts between MLB frame  420  and backplate  410  that are electrically isolated from the MLB  403  itself. Alternatively, one or more grounding pins  415  can make one or more direct contacts to various grounded regions on MLB  403 . Grounding pins  415  can be, for example, pogo pins, although other suitable grounding pin types may be used. 
     In this way, MLB frame  420 , backplate  410  and grounding pins  415  can combine to form an effective EMI or RF shield that can contain RF energy generated by various components on MLB  403 . Moreover, the RF shield can also protect circuits such as the integrated wireless/audio card or other sound component  402  from RF leakage and interference that can seriously impact the wireless performance of such an integrated wireless/audio card. 
     Turning next to  FIG. 9 , the rear bracket and its surrounding region is shown in close-up side cross-sectional view for purposed of clarity. As yet another example of a multifunctional separate ground component, rear bracket  430  can provide localized grounding for one or more associated electrical components, as well as providing overall structural support at various locations and assistance in the mechanical interaction between body  202  and lid  204  of portable computing device  200 . In various embodiments, rear bracket  430  can act as a cantilever beam with respect to body  202  and lid  204 . Accordingly, rear bracket  430  can be formed of a strong, lightweight, and resilient material, such as a magnesium or magnesium alloy. In addition, rear bracket  430  can aid in the distribution of high concentration loads that if applied to MLB frame  420  without dissipation could adversely affect the bond between MLB frame  420  and the outer enclosure. 
     Furthermore, rear bracket  430  can be formed to include vent like structures  436  that can facilitate the transfer of air between the outer housing of the portable computing device and the external environment, while at the same time obscuring an interior view of the portable computing device from the outside. Rear bracket  430  can also be adapted to transfer mechanical loads from lid  204  to body  206  by way of a display clutch  450  to MLB frame  420  and/or backplate  410 . While rear bracket  430  can form a localized separate ground structure, this rear bracket can also have a plurality of rear bracket tabs  435  that directly contact MLB frame  420 , such that these two separate ground structures are directly electrically connected as part of the universal grounding structure of portable computing device  200 . Rear bracket tabs  435  can be integrally formed as a part of rear bracket  430 , and can be, for example, beveled contact points that are specifically machined into the rear bracket  430  during its manufacture. 
     Display chassis  440  may also serve as a localized separate ground component. Unlike separate ground components  410 ,  420  and  430 , display chassis is located in the lid  204  rather than the body  202  of portable computing device  200 .  FIG. 10A  illustrates in front elevation view the lid  204  of the exemplary portable computing device of  FIG. 7 , while  FIG. 10B  illustrates the lid in side cross-sectional view. Lid  204  of the subject portable computing device can include a display screen  206 , a display cover  207 , and a surrounding bezel  209 , as well as a display chassis  440  and display clutch assembly  450 . Display chassis  440  can essentially comprise a metal or otherwise electrically conducting plate or thin component that is sandwiched between the back of display screen  206  and the outer housing of the device. In some embodiments, display chassis  440  can form a frame situated behind and/or at or about the outer edges of display screen  206 , with the frame having a missing center portion. Display chassis  440  essentially serves as a localized ground for the display, any antenna, and any other electrical components that may be included within lid  204 . 
     For example, a driver or other printed circuit board (not shown) associated with display screen  206  can be located at or near a bottom portion of lid  204  when the lid is in an upright position, with such an electrical component being coupled to display chassis  440  at that location. Power, ground and other potential electrical wires may run from lid  204  to body  202 , such as at or near clutch connectors  452 . Such wiring can include display chassis wiring  445 , which serves to connect display chassis  440  with one or more contact points on rear bracket  430 . One or more display clutch assembly brackets or connectors may serve as intermediaries between display chassis wiring  445  and the contact points on rear bracket  430 . Of course, each of these components, including any intermediaries, are all electrically conducting, and any such components in the electrical path wind up being part of the ground plane or universal grounding structure  400  of the device. 
     As in the case of various forgoing separate localized ground components and connectors in body  202 , various parts of the electrical grounding structure found in lid  204  can also provide additional functionalities. For example, display clutch assembly  450  can include clutch connectors  452  that mechanically connect to and transmit loads to MLB frame  420  and/or rear bracket  430  at suitable connector points. Display clutch assembly  450  can be housed within display clutch barrel  454  having back portion  456  that can be part of lid  204 . Back portion  456  can be joined to display clutch cover  458  resulting in display clutch seam  459 . In the described embodiment, display clutch seam  459  cannot be seen from the back by a user when portable computing device  200 , and in particular, top cover  204  is in the closed position. Furthermore, when top cover  204  is in the open position, clutch barrel seam  459  aligns with an associated TPU seam (not shown) giving the impression of continuity even in those areas not expected to be seen in normal operational use. 
     As shown in greater cross-sectional detail in  FIG. 10C , display clutch assembly  450  can enclose and therefore hide from view a number of electrical and mechanical components. For example, display clutch assembly  450  can enclose RF antenna  460 , as well as various mechanical items, such as structural and snap connector items. RF antenna  460  can be electrically coupled to display chassis  460 , as well as to display chassis wiring  445  that connects the localized separate ground structures found in lid  204  and body  202 . The location of display clutch barrel seam  459  can provide for a longer uninterrupted span for top cover  204 . Back portion  456  can include a number of snap connectors  457  that are used to secure the display clutch cover  458  to the back portion  456 . 
     Although the foregoing invention has been described in detail by way of illustration and example for purposes of clarity and understanding, it will be recognized that the above described invention may be embodied in numerous other specific variations and embodiments without departing from the spirit or essential characteristics of the invention. Certain changes and modifications may be practiced, and it is understood that the invention is not to be limited by the foregoing details, but rather is to be defined by the scope of the appended claims.

Metadata:
Filing Date: 20130822
Publication Date: 20171128
Grant Date: 20171128
Priority Date: 20091016
Inventors: THOMASON GARY
FETTERMAN KEVIN S.
DEFOREST LAURA M.
HOPKINSON RON
GOLDBERG MICHELLE
GOEL RUCHI
RAFF JOHN
HIBBARD TIMOTHY S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1688", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1662", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1662", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1662", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 43879307