PATENT DOCUMENT

Publication Number: US-9819378-B2
Application Number: US-201414299959-A
Country: US
Kind Code: B2

Title: Methods for forming fiber composite structures

Abstract:
An accessory unit includes a front flap and a rear cover. The rear cover includes a recessed portion that defines a chamber and a frame that extends about an opening of the chamber. The chamber is configured to receive a consumer electronic device, and the frame is configured to hold the consumer electronic device therein. For example, the frame may define a multi-sided cross-section with an inner edge thereof configured to engage a chamfered edge of the consumer electronic device. The front flap may include segments formed from panels with folding regions therebetween, which allow the front flap to fold. Further, an end region of the front flap hingedly couples the front flap to the rear cover, such that the front flap may be moved between open and closed configurations.

Claims:
What is claimed is: 
     
       1. A method of forming a composite structure, the method comprising:
 forming a ring having a first set of fibers arranged in a first direction, the ring having a first side and opposing second side; 
 forming a first reinforcement structure and a second reinforcement structure, each reinforcement structure including a reinforcing agent and having a surface with a scrim layer coupled thereto, each scrim layer having a second set of fibers; and 
 reinforcing the ring by coupling the first reinforcement structure to the first side of the ring and the second reinforcement structure to the second side of the ring such that the first reinforcement structure is non-contiguous with the second reinforcement structure, wherein a first scrim layer is positioned between the first reinforcement structure and the ring and a second scrim layer is positioned between the second reinforcement structure and the ring, wherein the second set of fibers are arranged in second direction different than the first direction of the first set of fibers preventing migration of the reinforcing agent into the ring. 
 
     
     
       2. The method of  claim 1 , wherein forming the ring comprises:
 forming a roll of multiple layers of a fiber material, the fiber material including the first set of fibers arranged in the first direction; and 
 cutting a slice from the roll along a plane substantially parallel to the first direction, the slice corresponding to the ring. 
 
     
     
       3. The method of  claim 2 , wherein forming a roll of multiple layers of a fiber material comprises:
 winding the multiple layers of fiber material around a drum. 
 
     
     
       4. The method of  claim 2 , wherein the roll includes between about 20 and about 30 layers of fiber material. 
     
     
       5. The method of  claim 1 , wherein the each of the first reinforcement structure and a second reinforcement structure includes a sheet of carbon fiber reinforced plastic. 
     
     
       6. The method of  claim 5 , wherein the sheet of carbon fiber reinforcement plastic has a thickness of between about 0.05 mm and 0.5 mm. 
     
     
       7. The method of  claim 1 , wherein at least one of the first set of fibers and the second set of fibers includes glass fibers. 
     
     
       8. The method of  claim 1 , further comprising:
 shaping the ring in accordance with a predetermined shape. 
 
     
     
       9. The method of  claim 8 , wherein shaping the ring comprises:
 placing the ring in a mold having the predetermined shape. 
 
     
     
       10. The method of  claim 9 , further comprising:
 heating the ring while within the mold. 
 
     
     
       11. A method of forming a composite structure, the method comprising:
 forming a roll by wrapping layers of a fiber material around a barrel, each layer of fiber material having fibers arranged substantially unidirectionally with respect to each other in a first direction; 
 removing a ring from the roll by cutting along a plane substantially parallel to a direction of the unidirectionally arranged fibers, the ring having a first side and opposing second side; and 
 reinforcing the ring by coupling a first reinforcement structure to the first side of the ring and a second reinforcement structure to the second side of the ring such that the first reinforcement structure is non-contiguous with the second reinforcement structure, wherein a first scrim layer is positioned between the first reinforcement structure and the ring and a second scrim layer is positioned between the second reinforcement structure and the ring, wherein each of the first and second scrim layers includes a second set of fibers arranged in second direction different than the first direction. 
 
     
     
       12. The method of  claim 11 , wherein wrapping the layers of fiber material comprises wrapping the layers of fiber material multiple times around a drum. 
     
     
       13. The method of  claim 12 , wherein the layers of fiber material are wrapped to a thickness of between about 20 and 30 layers of fiber material. 
     
     
       14. The method of  claim 11 , further comprising:
 heating the ring in a mold having a mold shape such that the ring takes on a shape corresponding to the mold shape. 
 
     
     
       15. The method of  claim 14 , wherein each of the first reinforcement structure and the second reinforcement structure includes a reinforcing agent. 
     
     
       16. The method of  claim 15 , wherein each of the first scrim layer and the second scrim layer prevents migration of the reinforcing agent into the ring. 
     
     
       17. A method of forming a supportive frame, the method comprising:
 forming a ring having a first set of fibers arranged in a first direction, the ring having a first side and opposing second side; 
 reinforcing the ring by coupling a first reinforcement structure to the first side of the ring and a second reinforcement structure to the second side of the ring such that the first reinforcement structure is non-contiguous with the second reinforcement structure, wherein a first scrim layer is disposed between the first reinforcement structure and the ring and a second scrim layer is disposed between the second reinforcement structure and the ring, wherein each of the first scrim layer and the second scrim layer have a second set of fibers arranged in second direction different than the first direction; and 
 shaping the ring by placing the ring in a mold having a mold shape such that the ring takes on a shape corresponding to the mold shape. 
 
     
     
       18. The method of  claim 17 , wherein at least one of the first set of fibers and the second set of fibers includes glass fiber reinforced plastic. 
     
     
       19. The method of  claim 17 , wherein the first and second reinforcement regions include carbon fiber reinforced plastic. 
     
     
       20. The method of  claim 17 , wherein the shaping the ring comprises shaping the ring into a rectangular ring shape.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This is a divisional of U.S. application Ser. No. 13/725,891 filed Dec. 21, 2012, now U.S. Pat. No. 8,790,758, which is a continuation of International Application No. PCT/US2012/027921, with an international filing date of Mar. 6, 2012, entitled “ACCESSORY UNITS FOR CONSUMER ELECTRONICS DEVICES AND RELATED ASSEMBLIES AND METHODS”, and also claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/607,165, filed Mar. 6, 2012 and entitled “ACCESSORY UNITS FOR CONSUMER ELECTRONIC DEVICES AND RELATED ASSEMBLIES AND METHODS”, each of which are incorporated by reference in their entirety for all purposes. 
    
    
     FIELD 
     The present disclosure relates generally to accessory units, and more particularly to accessory units for consumer electronic devices and related assemblies and methods. 
     BACKGROUND 
     As advancements have been made in the field of consumer electronic devices, development of associated accessory units has also occurred. In this regard, some accessory units such as cases are designed to protect consumer electronic devices. Other accessory units are configured to provide consumer electronic devices with increased functionality. 
     While existing accessory units may function suitably for their intended purposes, further advancements may be desirable. For example, increased functionality or protection for the associated consumer electronic devices may be desirable. 
     Accordingly, a need for continued advancement is the field of accessory units may exist. 
     SUMMARY 
     This paper describes various embodiments of an accessory for an electronic device. 
     The present disclosure provides an accessory unit which may be combined with a consumer electronic device to form an assembly. The accessory unit may include a front flap with segments formed from panels and folding regions therebetween that provide the front flap with flexibility. The accessory unit may also include a rear cover that includes a recessed portion, which may be formed from a flexible material, and which defines a chamber. The rear cover may also include a frame coupled to the recessed portion that extends about an opening to the chamber. 
     The frame may be formed from a material that is relatively more rigid than the flexible material of the recessed portion. In this regard, the frame may function to retain a consumer electronic device in the chamber of the recessed portion via interference fit. For example, the frame may define a multi-sided cross-section, and an inner edge of the frame may be configured to engage a chamfered edge of the consumer electronic device. Thereby, the accessory unit may retain the consumer electronic device in the chamber while substantially avoiding blocking an upper surface of the consumer electronic device at which a display may be positioned. 
     The front flap may also include an end region that allows the front flap to pivot relative to the rear cover. The front flap may be formed from multiple layers of material, and the layers may only be bonded to one another at the longitudinal ends of the end region such that the end region is provided with increased flexibility. However, in order to improve alignment of the front flap with respect to the rear cover, an end segment may be provided in the end region of the front flap. The end segment may be formed from a panel of a relatively stiff material (e.g., steel). However, the end segment may not extend across the full width of the end region such that the end region remains flexible. 
     In one embodiment, an accessory unit is described. The accessory includes at least a front flap and a rear cover where the front flap includes a plurality of segments, 
     a folding region between each of the segments arranged to allow the segments to fold with respect to each other, and an end region. The rear cover includes at least a recessed portion formed from a flexible material that defines a chamber and a frame coupled to the recessed portion and extending about an opening of the chamber where the frame is formed of a material that is more rigid than the flexible material of the recessed portion. In the described embodiments, the end region of the front flap hingedly couples the front flap to the rear cover and the front flap is configurable between a closed configuration in which the front flap at least partially covers the opening to the chamber and an open configuration in which the opening to the chamber is at least partially uncovered. 
     In another embodiment, the accessory unit is used to protect a consumer electronic device that is retained in the chamber by the frame, and where the end region of the front flap hingedly couples the front flap to the rear cover and the front flap is configurable between a closed configuration in which the front flap at least partially covers the display of the consumer electronic device and an open configuration in which the display of the consumer electronic device is at least partially uncovered. 
     In one aspect of the described embodiment, a current position of the front flap in relation to the consumer electronic product causes the consumer electronic product to operate in a state in accordance with the current position of the front flap. 
     In still another embodiment, a method for manufacturing an accessory unit is described. The method is carried out by providing a first sheet of material and a second sheet of material, inserting a plurality of panels between the first sheet of material and the second sheet of material, coupling the first sheet of material to the second sheet of material, forming the first sheet of material and the second sheet of material into a front flap that is substantially planar and a recessed portion that defines a chamber, and coupling a frame to the recessed portion extending about an opening of the chamber. 
     In yet another embodiment, a composite structure is described. The composite structure includes at least a multi-sided ring of stacked unidirectional fiber layers aligned in a first direction, each fiber layer formed from a layer of material having binder and unidirectional fibers and each fiber layer having opposing first and second surfaces, wherein the ring of multiple fiber layers has an outer edge formed by the first surface of an outermost one of the fiber layers and has an inner edge formed by the second surface of an innermost one of the fiber layers. The multi-sided composite structure also includes a first and second specifically defined region of reinforcing fiber infused with the plastic binder during a composite structure formation operation, the first and second regions being non-contiguous and on opposite sides of the composite structure, the reinforcing agent providing enhanced structural strength for the infused sides. 
     A method of forming a reinforced multi-sided composite structure from layers of unidirectional fiber material and reinforcing binder, each layer of unidirectional fiber having unidirectional fiber and binder is described. The method is carried out by wrapping multiple layers of the unidirectional fiber material around a drum, the unidirectional fiber material being aligned in a first direction, removing a ring of the wrapped layers of unidirectional fiber material from the drum, masking a first reinforced region by applying a first scrim layer on a first exterior surface of the multi-sided composite structure formed of the unidirectional fiber material aligned in a second direction, the second direction being different than the first direction, masking a second reinforced region by applying a second scrim layer on a second exterior surface of the multi-sided composite structure formed of the unidirectional fiber material aligned in the second direction, applying a first strip of reinforcing agent at an exterior surface of the first scrim layer, applying a second strip of reinforcing agent at an exterior surface of the second scrim layer, and heating the removed ring of the wrapped layers of unidirectional fiber material and first and second strips of reinforcing agent in a mold. 
     In yet another embodiment, method of forming a laminated fabritic structure is described. The method is carried out by performing at least the following operations: 
     receiving a first layer of fabric, forming a first adhesive layer by pre-laminating a first adhesive layer to the first layer of fabric, receiving a second layer of fabric, adding the second layer of fabric proximate to the first layer of adhesive, heating the first and second layers of fabric and the first adhesive layer, forming the laminated fabritic structure by cooling the first and second layers of fabric and the first adhesive layer subsequent to the heating in a mold, wherein the first and second fabric layers take on the form of the mold and wherein the first adhesive layer provides a structural support layer for the laminated fabritic structure, and releasing residual stress in the laminated fabritic structure by alternately heating and cooling the laminated fabritic structure. 
     Related methods and assemblies are also provided. Other apparatuses, methods, features and advantages of the disclosure 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 apparatuses, assemblies, methods, features and advantages be included within this description, be within the scope of the disclosure, 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 accessory units, assemblies, and method for manufacturing accessory units. These drawings in no way limit any changes in form and detail that may be made to the disclosure by one skilled in the art without departing from the spirit and scope of the disclosure. 
         FIG. 1A  illustrates a perspective view of an accessory unit comprising a front flap and a rear cover wherein the front flap is in an open configuration according to an example embodiment of the disclosure; 
         FIG. 1B  shows a cross sectional view of the accessory unit shown in  FIG. 1A  in the open configuration; 
         FIG. 2A  illustrates a perspective view of the accessory unit of  FIG. 1A  with the front flap in a closed configuration; 
         FIG. 2B  illustrates a cross sectional view of the accessory unit of  FIG. 2A  with the front flap in a closed configuration; 
         FIG. 3A  illustrates an exploded perspective view of the accessory unit of  FIG. 1A  in the open configuration 
         FIG. 3B  schematically illustrates a method for forming a rigid structure from an adhesive and layers of fabric material according to an example embodiment of the present disclosure; 
         FIG. 4A  illustrates a rolled up glass fiber reinforced plastic sheet ready to be sliced into glass fiber reinforced plastic hoops; 
         FIGS. 4B &amp; 4C  illustrate the positive effect obtained by adding glass scrim fabric between a glass fiber reinforced plastic hoop and carbon fiber reinforced plastic strips; 
         FIGS. 4D &amp; 4E  illustrate how the mold cavity forms and sets the frame; 
         FIG. 4F  illustrates a perspective view of a frame of the rear cover of the accessory unit of  FIG. 1A  and cross-sectional views through the frame; 
         FIG. 4G  is a block diagram describing a process for creating a frame for the rear cover of the accessory unit of  FIG. 1A ; 
         FIG. 5  illustrates a top view of a frame for a rear cover of an accessory unit according to an alternate example embodiment of the present disclosure; 
         FIG. 6  illustrates a partial enlarged exploded view of the rear cover including a speaker cover; 
         FIG. 7  illustrates a cross-sectional view through an assembly comprising the accessory unit of  FIG. 1A  and a consumer electronic product according to an example embodiment of the present disclosure; 
         FIG. 8  illustrates a cross-sectional view through the assembly of  FIG. 7  at a button of the consumer electronic device and a corresponding embossed portion of the rear cover of the accessory unit; 
         FIG. 9  schematically illustrates a method for manufacturing an accessory unit according to an example embodiment of the present disclosure; 
         FIGS. 10A and 10B  illustrate an embodiment of the accessory unit having a bi-stable frame portion for providing an audio path; 
         FIG. 11A  illustrates a top view of a corner of the rear cover of the accessory unit comprising a cutout portion configured to act as an acoustic wave guide according to an example embodiment of the present disclosure; 
         FIG. 11B  illustrates a side sectional view of the cutout portion of  FIG. 11B ; 
         FIG. 12  is a block diagram of an arrangement of functional modules utilized by a portable media device; and 
         FIG. 13  is a block diagram of an electronic device suitable for use with the described embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     These and other embodiments are discussed below with reference to  FIGS. 1-13 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. For the remainder of this discussion, an accessory unit suitable for use with an electronic device will be described. In particular, for simplicity and clarity, for the remainder of this discussion, the electronic device takes the form of a handheld electronic device such as a tablet computer. 
     In this regard,  FIG. 1A  illustrates an embodiment of an accessory unit  100  according to the present disclosure. As illustrated, the accessory unit  100  may comprise a front flap  200  and a rear cover  300 . The front flap  200  may include a plurality of segments  202  and a folding region  204  positioned between each of the segments. The folding regions  204  may be configured to allow the segments  202  to fold with respect to each other. The front flap  200  may also include an end region  206 . The end region  206  hingedly couples the front flap  200  to the rear cover  300 . 
     In a specific embodiment, each of segments  202  can include one or more inserts disposed therein. By way of example, segments  202  can include a pocket region where the inserts are placed or alternatively the inserts may be embedded within the segments (e.g., via insert molding). If pockets are used, the pocket region can have a size and shape to accommodate corresponding inserts. The inserts can have various shapes but are most typically shaped to conform to the overall look of front flap  200  (e.g., rectangular). The inserts can be used to provide structural support for front flap  200 . That is, the inserts can provide stiffness to the cover assembly. In some cases, the inserts may be referred to as stiffeners. The inserts can be formed of rigid or semi-rigid material adding resiliency to front flap  200 . Examples of materials that can be used include plastics, fiber glass, carbon fiber composites, metals, and the like. Some of the inserts can be formed of resilient material such as plastic but also arranged to accommodate other components such as magnetic elements described below. Some of the magnetic elements can take the form of magnets at least one of which can interact with a magnetic sensor disposed within an electronic device associated with accessory unit  100 . Some of the magnets can also be arranged to form a magnetic attraction with an attractable magnetic element disposed with at least one insert. In one embodiment, attractable magnetic element can be formed of steel, or other ferromagnetic material, and take the shape of a thin sheet incorporated within an insert. 
     Front flap  200  can be relatively stiff except along folding regions  204  that are thinner and do not include the inserts (e.g., allows folding) making front flap  200  more robust and easier to handle. In one embodiment segments  202 - 1 ,  202 - 2 , and  202 - 3  can be related to segment  202 - 4  in size in the proportion of about 0.72 to 1 meaning that segments  202 - 1 ,  202 - 2 , and  202 - 3  are sized in width to be about 72% of the width of segment  202 - 4 . In this way, a triangular support structure having appropriate angles can be formed by positioning segments  202  in a manner described in U.S. patent application entitled, “CONSUMER ELECTRONIC PRODUCT” by Lauder et al. filed Dec. 17, 2010 having application Ser. No. 12/971,536 which is incorporated herein by reference in its entirety. 
     One approach to forming at least one triangular support structure can include segment  202 - 1  having a plurality of magnets and be arranged to fold with respect to segments  202 - 2  through  202 - 4  in such a way that at least one magnetic element within segment  202 - 1  magnetically attract a magnetically active insert within segment  202 - 4 . In this way, segments  202 - 1  and segment  202 - 4  can be magnetically bound together forming a first triangular support structure. In one embodiment, the triangular support structure formed by folding segment  202 - 1  onto segment  202 - 4  can be used as a support structure for accessory device  100 . In this way, any electronic component supported by accessory device  100  can also be supported. For example, when used as a support, an electronic device having a display and supported by accessory device  100  can be placed in such a way that visual content can be displayed at about 75o in relation to a horizontal surface. In another example, front flap  200  can be folded to form a second triangular support structure that can be used as a keyboard support. It should be noted, however, that these are only representative examples of many other support structures that can be formed by front flap  200 . 
     The rear cover  300  may include a recessed portion  302 , also referred to as a bucket, and a frame  304 . The recessed portion  302  may include a plurality of sidewalls  306   a - d  (collectively, “ 306 ”) and a bottom wall  308  that define a chamber  310 . The recessed portion  302  may include one or more apertures  312   a - e  (collectively, “ 312 ”) and/or one or more embossed portions  314   a - b  (collectively, “ 314 ”). 
     The frame  304  may be coupled to the recessed portion  302  and extend about an opening  316  of the chamber  310 . As will be described in further detail below, the recessed portion  302  of the rear cover  300  may be formed from a flexible material. Additionally, the frame  304  may be formed from a material that is more rigid than the flexible material of the recessed portion  302 . In this regard, the frame  304  of the rear cover  300  may be configured to retain a consumer electronic device in the chamber  310 , as discussed in detail below. 
     As noted, above, the end region  206  of the front flap  200  may hingedly couple the front flap to the rear cover  300 . In order to stiffen the end region  206  such that the end region may maintain alignment of the front flap  200  with respect to the rear cover  300 , the end region may include an end segment  208 . In particular, the end segment  208  may be configured to strengthen the end region  206  such that the end region maintains alignment of outer edges  210   a - c  (collectively, “ 210 ”) of the front flap  200  with respect to the frame  304  of the rear cover  300 . 
     The end region  206  may include a material that is flexible and which thereby allows the end region to bend. However, as a result of employing a flexible material in the end region  206 , without the end segment  208  the front flap  200  may tend to bend relative to the rear cover  300  at the end region in undesirable directions other than about a major axis  212  through the end region under certain circumstances. In this regard, the end segment  208  may be configured to prevent misalignment of the outer edges  210  of the front flap  200  with respect to the frame  304  when the accessory unit is subjected to forces in directions other than perpendicular to a major axis  212  through the end region  206 . 
     The front flap  200  may be configurable between an open configuration (see, e.g.,  FIG. 1A ) and a closed configuration (see, e.g.,  FIG. 2A ). In the open configuration, the front flap  200  is displaced relative to the rear cover  300  such that the opening  316  to the chamber  310  is at least partially uncovered. For example,  FIG. 1A  illustrates a fully open configuration in which the front flap  200  is out of contact with the frame  304  and the front flap defines a substantially planar configuration. However, the front flap  200  may be configured in a variety of other open configurations, as discussed for example in U.S. patent application entitled, “CONSUMER ELECTRONIC PRODUCT” by Lauder et. al. filed Dec. 17, 2010 having application Ser. No. 12/971,536 which is incorporated herein by reference in its entirety. 
     As illustrated in  FIG. 2A , the edges  210  of the front flap  200  may contact the frame  304  when the front flap is in the closed configuration. Accordingly, the front flap  200  may define a substantially planar configuration when moved to the closed configuration. In this regard, the end segment  208  may be substantially coplanar with the other segments  202  and the folding regions  204  of the front flap when the front flap is in the folded configuration. However, a portion of the end region  206  adjacent the end segment  208  bends to enable the end region to function as a hinge, as noted above. 
     In some embodiments, as illustrated in  FIG. 2A , the frame  304  may extend outwardly beyond the edges  210  of the front flap  200 . In this regard, the frame  304  may function to protect a consumer electronic device received in the chamber  310  in the rear cover  300  from damage to the edges thereof when dropped or otherwise subjected to impact. However, in other embodiments the edges  210  of the front flap  200  and the frame  304  may extend to the same dimensions, or the edges of the front flap may extend beyond the frame. 
     The material(s) defining the accessory unit  100  may vary. In one example embodiment, the entire accessory unit  100  may be formed from a single material. However, as noted above, in other embodiments it may be desirable to form the accessory unit  100  from multiple materials to take advantage of differing material properties. 
     In this regard,  FIG. 3A  illustrates an exploded view of one embodiment of the accessory unit  100  in the open configuration. As illustrated, the accessory unit  100  may include a single sheet of material that defines an inner layer  102  of the front flap  200  and the recessed portion  302  of the rear cover  300 . Further, the accessory unit  100  may include a single sheet of material that defines an outer layer  104  of the front flap  200  and the recessed portion  302  of the rear cover  300 . In this regard, the recessed portion  302  of the rear cover  300  and the front flap  200  may be at least partially integrally formed in one embodiment. In this regard, a pleasing continuous appearance may be provided. However, the rear cover  300  and the front flap  200  may be formed from separate materials in other embodiments. 
     The material(s) defining the inner layer  102  and the outer layer  104  may be the same or different. In one embodiment the inner layer  102  may include a microfiber material and the outer layer  104  may include poly urethane type materials such as PUK. In this regard, the inner layer  102  and the outer layer  104  may include materials configured to provide durability, provide flexibility, protect a consumer electronic device, and/or a pleasing aesthetic appearance. In some embodiments the inner layer  102  may also be configured to passively clean the consumer electronic device, which may come into contact with the inner layer while held therein. 
     The accessory unit  100  may further include one or more additional materials between the inner layer  102  and the outer layer  104  in some embodiments. For example, the accessory unit  100  may include one or more panels  106 . The panels  106 , which may include fiberglass, steel, carbon fiber, plastic, or other relatively rigid materials in some embodiments, may be configured to define the structure of the segments  202  of the front flap  200 . In turn, the areas between the panels  106  may define the folding regions  204  of the front flap  200 , with the inner layer  102  and the outer layer  104  providing the folding regions with flexibility. 
     The accessory unit  100  may further include one or more magnetic elements in the front flap  200 . For example, one or more magnetic elements  108  may be configured to interact with an attachment feature of a consumer electronic device received in the rear cover  300 . For example, the magnetic elements  108  may be magnetically attracted to the attachment feature of the consumer electronic device when the accessory unit  100  is in a closed configuration such that the front flap  200  is releasably retained in this configuration. The front flap  200  may further include a magnetic element  110  configured to interact with a magnetically sensitive sensor configured to detect presence, absence, or a change from presence to absence or vice versa of the magnetic element. For example, the magnetically sensitive circuit may include a Hall Effect sensor. Various other details with respect to example embodiments of the magnetic elements  108 ,  110  of the accessory unit  100 . 
     As an example, the Hall Effect sensor can respond to the presence (or absence) of the magnetic field by generating a signal. The signal can be used to alter an operating state of the electronic device. Accordingly, magnetic element  110  can be positioned on front flap  200  in a location that triggers the Hall Effect sensor to generate the signal when the cover is placed on or in proximity to a surface of the consumer electronic device. The signal can indicate that the front flap  200  is in a predetermined position relative to the consumer electronic device that can result in a change in an operating state of the consumer electronic device. For example, with the portion of front flap  200  having magnetic element  110  in proximity to the Hall Effect sensor, the magnetic field from magnetic element  110  can cause the Hall Effect sensor to generate a signal. The signal can, in turn, be used to alter the operating state to one consistent with functioning of the consumer electronic device being fully covered. 
     For example, in those situations where the consumer electronic device includes a display, the functioning of the consumer electronic product can be altered in such a way that the display is prevented from displaying visual content. On the other hand, when the portion of front flap  200  having magnetic element  110  is removed to the point where the Hall Effect sensor no longer responds to the magnetic field of magnetic element  110 , then the Hall Effect sensor can generate another signal. The other signal can result in the consumer electronic device entering another, different, operating state consistent with at least a portion of the display being uncovered and viewable. As with the example of the consumer electronic product having a display, when the Hall Effect sensor no longer detects the magnetic field from magnetic element  110 , then the functioning of the tablet computer can be altered such that the display is enabled to present visual content. It should be noted that the above described attachment feature, the magnetically sensitive circuit are discussed in U.S. patent application entitled, “CONSUMER ELECTRONIC PRODUCT” by Lauder et al. filed Dec. 17, 2010 having application Ser. No. 12/971,536 which is incorporated herein by reference in its entirety. 
     The accessory unit  100  may further include an end panel  112  between the inner layer  102  and the outer layer  104 , which may be configured to define the structure of a portion of the end region  206  at the end segment  208 . The end panel  112  may include fiberglass, steel, carbon fiber, plastic, or other relatively rigid materials in some embodiments. Accordingly, the material(s) defining the inner layer  102  and the outer layer  104  (e.g., microfiber and PUK) may include flexible materials that allow the front flap  200  to flex at the folding regions  204  and at the end region  206 , whereas the material(s) defining the panels  106 ,  112  may provide rigidity and stiffness. The front flap  200  may also include a reinforcement bar  114 . The reinforcement bar  114  may be configured to reinforce the outer edge  210   c  of the front flap  200  and the corners between the outer edge and the side edges  210   a,b  of the front flap. Accordingly, the reinforcement bar  114  may be formed from a relatively rigid material such as plastic, steel, carbon fiber, fiberglass, etc. 
     The accessory unit  100  may also include a speaker cover  116  in the rear cover  300  in some embodiments, as will be discussed below. In order to couple the various components of the front flap  200  and the rear cover  300  together, the accessory unit  100  may further include one or more adhesive layers. In the illustrated embodiment, the rear cover  300  may include an adhesive layer  118 . The adhesive layer  118  may be configured to bond the layers of material comprising the rear cover  300  together. In particular, the adhesive layer  118  may bond to the outer layer  104  and the inner layer  102  with the speaker cover  116  bonded between the adhesive layer and the inner layer. 
     The front flap  200  may include inner and outer adhesive layers  120 ,  122  that bond the layers of material defining the front flap together. In particular, the outer adhesive layer  120  may bond the outer layer  104  to the reinforcement bar  114  and the panels  106  and the end panel  108 . Further, the inner adhesive layer  120  may bond the inner layer  102  to the reinforcement bar  114 , the panels  106 , and the end panel  112 . Accordingly, the adhesive layers  118 ,  120 ,  122  may laminate the layers and components comprising the front flap  200  and the rear cover  300  of the accessory unit  100  together. 
     In some embodiments the adhesive layers  118 ,  120 ,  122  may comprise a thermoplastic adhesive, such as a thermoplastic urethane adhesive, or a thermoplastic nylon adhesive. Such thermoplastic adhesives may act to form a structural element providing shape to inner layer  102  and outer layer  104  which on their own would not hold a solid shape. In this regard, thermoplastic adhesives may be melted in order to glue together multiple layers of material (e.g., inner layer  102  and outer layer  104 ). By varying the temperature at which the thermoplastic adhesives are heated, the pressure at which the operation takes place, the length of time the thermoplastic adhesives are exposed to the heat, and the temperature to which the thermoplastic adhesives are cooled after heating, the rigidity of the structure defined thereby may be controlled. For example, in one embodiment as the thermoplastic adhesive melts, it seeps into adjacent porous layers of material, forming a bonded structure. Longer periods of heating result in increased infusion into the material and can create a more rigid structure. One set of trials used a thermoplastic nylon adhesive of about 10 mm in thickness. In that trial a heating cycle performed at between 150 and 200 degrees Celsius for 1-2 minutes followed by a cooling cycle at between 5 and 15 degrees Celsius for 2-3 minutes achieved desirable results. The shape and stability of the structural element can be further improved by subjecting the rear cover to a subsequent heating and cooling process at less extreme temperatures, thereby allowing any residual stresses to be removed. 
     In this regard, the adhesive layer  118  in the rear cover  300  may comprise a thermoplastic adhesive that is melted in order to glue together multiple layers of material (e.g., inner layer  102  and outer layer  104 ) and provide structure to the rear cover. The particular process employed to use a thermoplastic adhesive as a structural element may vary. However,  FIG. 3B  illustrates an example embodiment of the steps involved in employing an adhesive to form a structural element. In this regard, as illustrated, the method may include pre-laminating an adhesive layer to a layer of fabric at operation  350 . For example, the adhesive layer  118  may be pre-laminated to the inner layer  102  of material. In one embodiment, the adhesive layer can be formed of thermoplastic adhesive such as thermoplastic nylon that forms a thermoplastic nylon adhesive layer applied at a thickness of about 10 mm. Pre-laminating the adhesive layer to the layer of fabric may be employed to properly position the adhesive layer with respect to the fabric layer such that misalignment between the layers is avoided in later steps. 
     After pre-laminating the adhesive layer to the layer of fabric at operation  350 , the method may further comprise adding a second layer of fabric proximate the adhesive layer at operation  352 . Thereby, the adhesive layer may be sandwiched between two layers of fabric. Thereafter the method may include heating the layers of material at operation  354 . This operation may melt the adhesive layer such the adhesive layer seeps into the fabric layers, forming a bonded structure. The heated layers of material may then be cooled in a mold at operation  356 . By cooling the layers of material while in a mold, the layers of material may take a shape defined by the mold. For example, the mold may include positive and negative portions (e.g., a protrusion and an indentation) that combine to form the shape of the recessed portion  302  of the rear cover  300 . Note that a mold may also be employed during heating the layers at operation  354 . By varying the pressure, time, and/or temperature to which the layers of material are exposed, the properties of the resulting laminated structure may be controlled. For example, a more rigid structure may be formed by heating the layers of material for a longer period of time or to a higher temperature. Conversely, a relatively less rigid structure may be formed by decreasing the temperature and/or time of heating, such that the adhesive seeps into the fabric layers less. For example, in one embodiment, the rear cover outer layer and rear cover inner layer are pressed together in a mold which forms the ultimate shape of the rear cover while heating the rear cover to a temperature between 150 and 200 degrees Celsius at which temperature the glue can properly cure. In other embodiments the heated mold could be replaced by other forms of heating, such as laser heating, which could selectively heat and cure portions of the glue without applying potentially damaging heat to the entire product. It should be noted that the rear cover can be quickly cooled to stabilize the shape formed by the mold. However, the rear cover can also be subjected to longer heating and cooling operations which allow residual stresses from the rapid heating and cooling processes to be removed, thereby stabilizing the shape and durability of the structural member. 
     Heating the layers at operation  354  and cooling the layers at operation  356  may result in a laminated structure having residual stresses. In order to alleviate these stresses, the laminated structure may be slowly heated and then slowly cooled to release the residual stresses at operation  358 . These temperatures may be relatively less than those employed in heating and cooling the layers at operations  354  and  356 . Accordingly, embodiments of a relatively rigid recessed portion  302  may be created in accordance with the above-described method from relatively non-rigid layers of material (i.e., an adhesive layer and two layers of fabric material). 
     However, in some embodiments the accessory unit  100  may include features configured to retain flexibility of the end region  206  of the front flap  200 . In this regard, in the embodiment of the accessory unit  100  illustrated in  FIG. 3A , the inner and outer adhesive layers  120 ,  122  of the front flap  200  may not completely cover the end region  206 . Rather, as illustrated, the inner and outer adhesive layers  120 ,  122  may include tabs  120 ′,  122 ′ that extend across the end region  206  proximate the side edges  210   a,b  of the front flap  200 . In particular, the tabs  120 ′,  122 ′ may be configured to extend across the end region  206  of the front flap  200  to the edge of the rear cover  300 . Accordingly, in embodiments in which the front flap  200  includes multiple layers of material, the layers of the material may be bonded at first and second longitudinal ends  206   a,b  of the end region  206  and decoupled therebetween due to the inner and outer adhesive layers  120 ,  122  defining tabs  120 ′,  122 ′ that bond the longitudinal ends of the end region. By bonding only a portion of the end region  206 , the inner layer  102  and the outer layer  104  may remain free to pivot with respect to each other. Thus, the end region  206  may function as a hinge as previously described. 
     Frame  304  can provide structural integrity to accessory unit  100 . In one embodiment, frame  304  can take the form of a robust and lightweight support structure having a multi-sided cross section and an overall shape of a perimeter of chamber  310 . Frame  304  can be formed of many materials. In the described embodiments, frame  304  can be formed primarily of Glass Fiber Reinforced Plastic (GFRP) that is also referred to as more simply fiberglass. GFRP is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It should be noted that the plastic matrix used to form many GFRP structures can be a thermosetting plastic (most often epoxy, polyester or vinyl ester) or thermoplastic. Moreover, GFRP is a lightweight, extremely strong, and robust material and has bulk strength and weight properties that compare favorably to metals and yet, unlike metals, is RF transparent. In this way, GFRP has properties that make it a good candidate for a structural element that is strong, resilient and yet is also RF transparent. This combination is particularly desirable when accessory unit  100  is used in conjunction with consumer electronic products that use RF communication circuitry. 
     When used as a structural element, the material that goes into forming frame  304  has to provide frame  304  with mechanical properties sufficient to securely retain the consumer electronic device within chamber  310  of rear cover  300  of accessory device  100 . Moreover, in addition to the ability to retain the consumer electronic product within chamber  310 , frame  304  must also retain enough flexibility to allow the consumer electronic device to be inserted and removed from chamber  310  numerous times without undue exertion by an end-user or potentially damaging accessory unit  100  or the consumer electronic product. However, typical configurations of glass fibers within the plastic matrix that form the basis for conventional GFRP material do not generally possess the requisite structural properties suitable for frame  304  under these conditions. 
     Therefore, in one embodiment, frame  304  can be formed with both conventional GFRP material (plastic matrix and glass fibers) but also a reinforcing agent selectively added to the GFRP material of frame  304  to increase the overall strength and rigidity of frame  304 . For example, even though conventional GFRP material does not possess the desired mechanical properties at a thickness suitable for use with accessory device  100 , a selected portion of frame  304  can be associated with the reinforcing agent. The reinforcing agent can be a material having a higher modulus of elasticity than the GFRP material that can also be integrally formed with the plastic matrix and glass fibers. One such material that can be used as the reinforcing agent is carbon fiber. In this way, frame  304  can be configured in such a way that portion of frame  304  can be infused with carbon fibers to take the form of carbon-fiber-reinforced polymer (or plastic) also referred to as CFRP, whereas a remaining portion can remain essentially GFRP. Since CFRP is a very strong and light, it is well suited as a reinforcing agent. However, carbon fiber is also conductive and is essentially RF opaque or at the very least adversely affects the ability of any RF component within the consumer electronic product from efficiently receiving or transmitting RF energy. This adverse impact on RF transmissivity is one reason (high cost being another) that prevents carbon fiber from being used to build the entire frame  304  as a frame made completely of carbon fiber would severely attenuate any RF communications to/from the consumer electronic device. Therefore, in order to preserve the RF communication ability of consumer electronics device and provide the requisite structural support, only a portion of frame  304  away from any RF antennae are associated with reinforcing agent in the form of carbon fiber. However, in order to optimize the desired mechanical properties of the combination of carbon fiber and frame  304  formed of GFRP, the carbon fiber is generally incorporated into the plastic matrix of the GFRP that goes into forming frame  304  in a manner described below with regards to  FIGS. 4A-4F . 
       FIGS. 4A-4F  illustrates a process by which frame  304  can be constructed. Frame  304  is made up of primarily GFRP. The GFRP material described above can also include an inhibitor which prevents it from setting until it achieves a specific temperature. As a result, before being heated at room temperature it has a taffy-like consistency and is highly malleable. Once heated to a temperature of about 150 degrees Celsius and cooled down it hardens into a somewhat flexible solid.  FIG. 4A  shows how the GFRP portion of the frame is initially formed. GFRP Sheet  400  having a thickness of about 20 glass fibers is rolled up as shown in  FIG. 4A . GFRP Sheet  400  can be wrapped around a drum in some cases to ensure the layers of GFRP Sheet  400  are wound tightly. The fibers in GFRP Sheet  400  are unidirectional and all run in a direction parallel to dashed planes  402 . GFRP Sheet  400  can be rolled until the roll is between 20 and 30 layers of fiber thick. After tightly rolling GFRP sheet  400 , it can then be cut into hoops by cutting along planes  402 , also parallel to the direction of the fibers resulting in a minimized number of glass fiber strands being severed. By making thin cuts, parallel to the direct of the fiber along rolled up GFRP Sheet  400  a number of hoops can be produced which have between 20 and 30 layers of glass fiber wrapped in a continuous circle. 
       FIG. 4B  illustrates a cross section of GFRP hoop  404 . GFRP hoop  404  has a rectangular cross section as can be seen in the figure. Carbon Fiber Reinforced Plastic (CFRP) strip  406  can be die-cut from a thin sheet of carbon fiber reinforced plastic. The sheet of CFRP can be of a thickness of between 0.05 mm and 0.5 mm depending on the ultimate stiffness desired. In this particular embodiment a thickness of about 0.1 mm can be used. Since GFRP has a taffy-like or sticky consistency once CFRP strips  406  are placed on both the bottom and top surfaces of GFRP Hoop  404  they will naturally adhere to it. This can be precisely accomplished by placing one side of GFRP Hoop  404  into a straightening tool, which straightens one side of the hoop into its ultimate length while CFRP strips  406  are adhered on both a top and bottom side of GFRP Hoop  404 . Once CFRP  406  is attached to GFRP Hoop  404  it can be placed in a mold for thermosetting. When the materials are set together they form a fused composite of GFRP and CFRP as can be seen in the two cross sectional snapshots shown in  FIG. 4B . Unfortunately, since the material substantially liquefies during the thermosetting process a significant amount of undesirable fiber migration can occur between the two materials. This results in varying stiffness along the carbon reinforced portion of frame  304 . As can be seen in the two cross-sectional cuts the migration patterns are not even uniform along the length of a single frame. Therefore, a method for reducing migration should be introduced. 
       FIG. 4C  shows one solution to the migration problem. Before CFRP strips  406  are attached to GFRP Hoop  404 , they are first attached to glass scrim fabric  408 . Glass scrim fabric  408  is a thin sheet of glass fiber fabric with fibers woven in a different direction than those found in GFRP Hoop  404 . In this way the fibers from GFRP Hoop  404  and CFRP Strips  406  can be substantially prevented from migrating. The results can be seen in  FIG. 4C . The CFRP Strips  406  remains densely positioned along the top and bottom sides of resulting frame structure  304 . By having dense sections of carbon fiber at the extreme top and bottom of frame  304  the moment of inertia of the structure can be enhanced. This structure functions in much the same way as a steel I-Beam concentrating the stiff portions of the frame at the top and bottom. Another major advantage of using carbon fiber is that its stiffness can vary dramatically based on the type and grade of precursor used to form it. While standard grades start at a modulus of about 230 GPa, the modulus used in this embodiment was about 377 GPa. 
       FIGS. 4D and 4E  illustrate the mold for heating and setting frame  304 . Mold  410  is designed to heat and shape GFRP Hoop  404  into frame  304  along while fusing CFRP Strips  406  to the top and bottom of GFRP Hoop  404  in mold portion  412 . As previously described CFRP Strips  406  are already positioned and stuck to GFRP Hoop  404 ; therefore straightened portion of GFRP Hoop  404  with attached CFRP Strips  406  can be easily positioned into mold portion  412  of mold  410 . Mold  410  includes a heating system which increases the temperature and malleability of the hoop, further easing the process of fitting the rest of the hoop into mold cavity  410 .  FIG. 4E  shows a cross section of one portion of the mold in mold portion  412 . Upper mold portion  414  is then pressed down upon the mold giving frame  304  its ultimate shape. Once frame  304  is allowed to cool, and any excess flashing is removed, frame  304  is fully formed. 
       FIG. 4F  shows a perspective view of finished frame  304 . The result is a GFRP frame with a single side reinforced by carbon fiber. This solution removes any need for a mechanical coupling, as the two materials are fused tightly together due to the interaction of the resin during the setting process. In this way the glass fibers can run continuously around the entire loop, and the carbon fibers lie on the top and bottom portions of the frame, resisting any bending motions applied in the y-z plane. Beneficially, since the carbon fibers do not cover the lateral sides of the frame, motion in the x-z plane is only incidentally affected, easing the removal of the consumer electronic device. While this technique has been described in the context of stiffening one edge of the frame of an accessory device it should be noted that it could be applicable over a large range of applications. Any application that requires portions of varying stiffness could greatly benefit from this combination of glass and carbon fiber composite. This configuration even allows a designer to pick which directions to stiffen. 
       FIG. 4G  shows flow chart  420  in which the frame creation process is summarized. In a first step  422  a Glass Fiber Reinforced Plastic (GFRP) sheet is received. In a second step  424  the GFRP Sheet is tightly wound to a thickness of between 20 and 30 layers. A drum may be used to wrap the GFRP around to increase the tightness of the wrap. After the wrapping process is complete in step  426  the GFRP Sheet is cut thinly curt along the direction of the glass fibers to form thin GFRP Hoops. In a next step  428  a thin GFRP Hoop is placed in a straightening fixture, and two carbon reinforced plastic (CFRP) strips are adhered on a bottom and top surface of one side of the GFRP Hoop. In step  430  the carbon reinforced GFRP Hoop is now removed from the straightening fixture and placed in a mold. The mold heats and sets the carbon reinforced GFRP Hoop. Once complete the CFRP strips are securely fused to the GFRP Hoop in one continuous frame structure. Finally, in step  432  excess flash and waste from the molding process are removed and the frame is complete. 
     As illustrated in  FIG. 1A , the frame  304  includes a plurality of sides  304   a - d  that may define a rectangular configuration in some embodiments.  FIG. 5  illustrates a top view of an alternate embodiment of the frame. In the embodiment illustrated in  FIG. 5 , the frame  304 ′ also includes a plurality of sides  304   a ′- d ′. Three of the sides  304   a′, b′, d ′ are substantially similar to the sides  304   a, b, d  of the embodiment of the frame  304  illustrated in  FIG. 1A . 
     In particular, with reference to  FIG. 1A , a first side  304   d  of the frame  304  proximate to the end region  206  of the front flap  200  and the two sides  304   a,b  connected thereto are the same as the sides  304   a′, b′, d ′ of the frame  304 ′ of  FIG. 5 . However, the fourth side  304   c ′ of the frame  304 ′, which is positioned opposite to the first side  304   d ′ differs from the fourth side  304   c  of the frame  304  illustrated in  FIG. 1A . In this regard, the fourth side  304   c ′ of the frame  304 ′ of  FIG. 5  defines a bowed configuration. In particular, the fourth side  304   c ′ bows inwardly toward the center of the frame  304 ′. This bowed configuration is configured to apply an inwardly directed force when a consumer electronic device is received in the rear cover such that the forth side of the frame does not sag downwardly. 
       FIG. 6  illustrates an enlarged exploded view of recessed portion  302  of the rear cover  300 . As illustrated, the speaker cover  116  may include a layer of material that is relatively smaller than the other layers of material  102 ,  104 , and  118  defining the rear cover  300 . In this regard, the speaker cover  116  may be configured to be slightly larger than the aperture  312   e  which is defined through the remaining layers  102 ,  104 ,  118  of the rear cover  300  such that the peripheral edges of the speaker cover  116  are configured to engage the inner layer  102  of the rear cover and the adhesive layer  118 . A plurality of apertures  124  may be defined in the speaker cover  116  such that sound waves may travel out of the accessory unit  100  through the apertures  124  in the speaker cover  116  and the aperture  312   e . In some embodiments the speaker cover  116  may be color matched to the inner layer  102  and/or the outer layer  104  to provide a pleasing aesthetic appearance. 
     In some embodiments the apertures defined through the rear cover  300  may be formed by laser ablation. In this regard, a laser may remove material from the accessory device  100  to define apertures therethrough. Further, in some embodiments laser ablation may be employed to remove material from a desired partial depth through the accessory device. For example, laser ablation may remove the outer layer  104  of material, while allowing one or more other layers of material comprising the accessory device  100  to remain. For example, by employing layers of material defining differing colors, laser ablation may be employed to remove the outer layer  104  in a pattern that defines a desired design. Accordingly, a pleasing aesthetic effect may be provided without requiring printing on the outer layer  104 , which may be less durable. 
     As noted above, the accessory unit  100  may be configured to hold a consumer electronic device in the chamber  310  defined in the rear cover  300 . In this regard,  FIG. 7  illustrates an enlarged partial cross-sectional view through an assembly  400  comprising the above-described accessory unit  100  and a consumer electronic device  500 . The consumer electronic device may include an iPad™, as produced by Apple, Inc. of Cupertino, Calif. However, the assembly may include other consumer electronic devices in other embodiments. 
       FIG. 7  illustrates the front flap  200  in the open configuration wherein a display  502  of the consumer electronic device  500  is fully uncovered. However, the front flap  200  may be configurable between a number of positions including open positions in which the display  502  is at least partially uncovered and one or more closed configurations in which the front flap at least partially covers the display. In both the open configurations and the closed configurations, the recessed portion  302  of the rear covers  300  wraps around a housing  504  of the consumer electronic device  500 . 
     The frame  304  of the rear cover  300  may retain the consumer electronic device  500  in the chamber  310 . As illustrated in  FIG. 7 , in one embodiment the frame  304  may define a triangular cross-section. The triangular configuration of the frame  304  allows an inner edge  318  of the frame to engage a chamfered edge  506  of the consumer electronic device  500 . Note, however, that the frame  300  may define other cross-sectional shapes that include an inner edge configured to engage a chamfered edge of a consumer electronic product in other embodiments. 
     Accordingly, the frame  300  may act via interference fit to retain the consumer electronic device  500  in the chamber  310 . Further, as illustrated, the frame  300  may substantially avoid contacting the display  502  in this configuration. This allows substantially all of the display  502  to remain visible, which may be desirable in embodiments in which the consumer electronics device includes a display that extends near the edges of the top surface thereof. 
       FIG. 8  illustrates a partial enlarged sectional view through the assembly  400  of  FIG. 7 . As noted above, the recessed portion  302  of the rear cover  300  may define one or more embossed portions. In this regard,  FIG. 8  illustrates an embossed portion  314   a  aligned with a button  508  of the consumer electronic device  500 . In this regard, the embossed portion  508  may allow a user to easily identify the location of the button  508  through tactile feel or visual recognition. Further, since the recessed portion  302  of the rear cover  300  may include one or more flexible materials, the embossed portion  314   a  may be depressed or otherwise manipulated to actuate the button  508 . 
     The other embossed portion  314   b  illustrated in  FIG. 1A  may be employed for similar purposes with respect to one or more additional buttons on the consumer electronic device  500 . Similarly, the apertures  312  may be employed to provide access to various components of the consumer electronic device such as audio, power, and data ports. Further, one of the apertures  312   c  may be configured to align with a camera lens of the consumer electronic device  500 . In this regard, the aperture  312   c  may be oversized relative to the size of the camera lens in order to ensure that the camera lens is not blocked even when the consumer electronic device is not perfectly aligned in the rear cover  300 . 
     A related method for manufacturing an accessory unit is also provided. As illustrated in  FIG. 9 , the method may include providing a first sheet of material and a second sheet of material at operation  600  and inserting a plurality of panels between the first sheet of material and the second sheet of material at operation  602 . Thereafter, the method may include coupling the first sheet of material to the second sheet of material at operation  604  and forming the first sheet of material and the second sheet of material into a front flap that is substantially planar and a recessed portion that defines a chamber at operation  606 . Additionally, the method may include coupling a frame to the recessed portion extending about an opening of the chamber at operation  608 . 
     In some embodiments coupling the sheets of material at operation  604  and forming the forming the sheets of material into a front flap and a recessed portion at operation  606  may be conduction substantially simultaneously. For example, the sheets may be coupled and formed into a front flap and recessed portion via a lamination process. However, these steps may be performed separately in other embodiments. Also, the front flap and the recessed portion may be formed substantially simultaneously in some embodiments or at different times in other embodiments. 
     The method may further include cutting holes in the recessed portion in some embodiments. Additionally, the method may include inserting a magnetic element between the first sheet of material and the second sheet of material. Inserting the magnetic element may be conducted simultaneously with inserting the panels at operation  602  in some embodiments. In this regard, the magnet element may be coupled to the panel prior to insertion of the panel between the sheets of material. 
       FIGS. 10A and 10B  illustrate an embodiment of accessory unit  100  having a bi-stable frame portion for providing an audio path. In those situations where accessory unit  100  is used with an electronic device having audio output capabilities, it may be desirable for at least portion  1002  of frame  304  to be flexible in such a way so as to possess bi-stable configuration. By bi-stable it is meant that in a first configuration shown in  FIG. 10A , bi-stable portion  1002  of frame  304  can take on a first, or closed, configuration. In the closed configuration, accessory unit  100  can block substantial amounts of audio energy provided by an audio output device (such as a speaker). Therefore, as shown in  FIG. 10B , bi-stable portion  1002  can transition from the closed configuration of  FIG. 10A  to an open configuration that provides audio path  1004 . In this way, audio output provided the by audio output device can be more readily heard by an end-user thereby greatly enhancing the end-user&#39;s listening experience. 
     In another embodiment, illustrated in  FIGS. 11A and 11B , another configuration for outputting sound from the accessory device  100  is provided. As illustrated in  FIG. 11A , which is a top view of a corner of the rear cover  300 , the recessed portion  302  may comprise a cutout portion  320 . For example, the cutout portion  320  may be formed by removing the inner layer  102  of material defining the recessed portion  300  via laser ablation in some embodiments. The cutout portion  320  may comprise a main chamber  322  and one or more of channels  324  extending there from toward the frame  304 . 
       FIG. 11B  illustrates a cross-sectional view through the rear cover  300  at the cutout portion  320 . As illustrated, the channels  324  may extend upwardly toward the frame  304 . Further, each channel  324  may align with an aperture  326  in the frame  304 . The chamber  322  of the cutout portion  320  may be configured to align with a speaker of a consumer electronic device received in the rear cover  300  such that sound outputted there from travels from the chamber through the channels  324  and upward and out through the apertures  326  in the frame  304 . Accordingly, the cutout portion  320  and apertures  326  in the frame may function as an acoustic wave guide that directs sounds out of the rear cover  300  through the front of the accessory device  100  in order to direct the sound at a user. 
       FIG. 12  is a block diagram of an arrangement  1200  of functional modules utilized by an electronic device. The electronic device can, for example, be tablet device  100 . The arrangement  1200  includes an electronic device  1202  that is able to output media for a user of the portable media device but also store and retrieve data with respect to data storage  1204 . The arrangement  1200  also includes a graphical user interface (GUI) manager  1206 . The GUI manager  1206  operates to control information being provided to and displayed on a display device. The arrangement  1200  also includes a communication module  1208  that facilitates communication between the portable media device and an accessory device. Still further, the arrangement  1200  includes an accessory manager  1210  that operates to authenticate and acquire data from an accessory device that can be coupled to the portable media device. 
       FIG. 13  is a block diagram of an electronic device  1350  suitable for use with the described embodiments. The electronic device  1350  illustrates circuitry of a representative computing device. The electronic device  1350  includes a processor  1352  that pertains to a microprocessor or controller for controlling the overall operation of the electronic device  1350 . The electronic device  1350  stores media data pertaining to media items in a file system  1354  and a cache  1356 . The file system  1354  is, typically, a storage disk or a plurality of disks. The file system  1354  typically provides high capacity storage capability for the electronic device  1350 . However, since the access time to the file system  1354  is relatively slow, the electronic device  1350  can also include a cache  1356 . The cache  1356  is, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to the cache  1356  is substantially shorter than for the file system  1354 . However, the cache  1356  does not have the large storage capacity of the file system  1354 . Further, the file system  1354 , when active, consumes more power than does the cache  1356 . The power consumption is often a concern when the electronic device  1350  is a portable media device that is powered by a battery  1374 . The electronic device  1350  can also include a RAM  1370  and a Read-Only Memory (ROM)  1372 . The ROM  1372  can store programs, utilities or processes to be executed in a non-volatile manner. The RAM  1370  provides volatile data storage, such as for the cache  1356 . 
     The electronic device  1350  also includes a user input device  1358  that allows a user of the electronic device  1350  to interact with the electronic device  1350 . For example, the user input device  1358  can take a variety of forms, such as a button, keypad, dial, touch screen, audio input interface, visual/image capture input interface, input in the form of sensor data, etc. Still further, the electronic device  1350  includes a display  1360  (screen display) that can be controlled by the processor  1352  to display information to the user. A data bus  1366  can facilitate data transfer between at least the file system  1354 , the cache  1356 , the processor  1352 , and the CODEC  1363 . 
     In one embodiment, the electronic device  1350  serves to store a plurality of media items (e.g., songs, podcasts, etc.) in the file system  1354 . When a user desires to have the electronic device play a particular media item, a list of available media items is displayed on the display  1360 . Then, using the user input device  1358 , a user can select one of the available media items. The processor  1352 , upon receiving a selection of a particular media item, supplies the media data (e.g., audio file) for the particular media item to a coder/decoder (CODEC)  1363 . The CODEC  1363  then produces analog output signals for a speaker  1364 . The speaker  1364  can be a speaker internal to the electronic device  1350  or external to the electronic device  1350 . For example, headphones or earphones that connect to the electronic device  1350  would be considered an external speaker. 
     The electronic device  1350  also includes a network/bus interface  1361  that couples to a data link  1362 . The data link  1362  allows the electronic device  1350  to couple to a host computer or to accessory devices. The data link  1362  can be provided over a wired connection or a wireless connection. In the case of a wireless connection, the network/bus interface  1361  can include a wireless transceiver. The media items (media assets) can pertain to one or more different types of media content. In one embodiment, the media items are audio tracks (e.g., songs, audio books, and podcasts). In another embodiment, the media items are images (e.g., photos). However, in other embodiments, the media items can be any combination of audio, graphical or visual content. Sensor  1376  can take the form of circuitry for detecting any number of stimuli. For example, sensor  1376  can include a Hall Effect sensor responsive to external magnetic field, an audio sensor, a light sensor such as a photometer, and so on. 
     Although the foregoing disclosure 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 disclosure may be embodied in numerous other specific variations and embodiments without departing from the spirit or essential characteristics of the disclosure. Certain changes and modifications may be practiced, and it is understood that the disclosure 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: 20140609
Publication Date: 20171114
Grant Date: 20171114
Priority Date: 20120306
Inventors: KENNEY KEVIN
MERRITT ROBERT MICHAEL
LAUDER ANDREW D.
BALAJI SANTHANA K.
SARTEE JARED A.
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T428/1362", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49801", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C65/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49801", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2305/22", "inventive": false, "first": false, "tree": "[]"}, {"code": "B65D25/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3888", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/7802", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/1362", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/1314", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/1314", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C65/7802", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/1362", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B65D25/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3888", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49801", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2305/22", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/1314", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C2011/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": true, "tree": "[]"}, {"code": "A45C11/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 49113104