PATENT DOCUMENT

Publication Number: US-10063269-B2
Application Number: US-201615219166-A
Country: US
Kind Code: B2

Title: Case for an electronic device and manufacturing methods for making a case

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 lip that extends about an opening of the chamber. The chamber is configured to receive a consumer electronic device, and the lip is configured to hold the consumer electronic device therein. The rear cover can include a shell formed from glass fiber reinforced plastics and a lip formed from a thermoplastic. 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. Methods of manufacturing the accessory unit are also disclosed.

Claims:
What is claimed is: 
     
       1. An accessory device for an electronic device, the accessory device comprising:
 a shell comprising a bottom wall and sidewalls extending from the bottom wall to define a cavity having size and shape in accordance with the electronic device; 
 a lip formed continuously along the sidewalls to define a planar surface, the lip capable of retaining the electronic device within the cavity; 
 a rigid material embedded in and extending along the lip; and 
 a front flap connected to the shell, the front flap having a size and shape capable of folding onto the planar surface, the front flap comprising:
 a first segment that carries a first magnetic element, 
 a second segment that carries a second magnetic element, and 
 a foldable region between the first segment and the second segment, wherein the first segment is foldable with respect to the second segment, and vice versa, based on the foldable region such that the first magnetic element magnetically couples with the second magnetic element and the first segment and the second segment form a three dimensional support structure for supporting the electronic device. 
 
 
     
     
       2. The accessory device of  claim 1 , wherein the rigid material comprises fiber strands. 
     
     
       3. The accessory device of  claim 1 , wherein the front flap extends directly from the lip. 
     
     
       4. The accessory device of  claim 1 , wherein:
 the shell comprises an opening for an operational component of the electronic device, 
 the shell comprises a first thickness, and 
 the shell comprises a second thickness around the opening, the second thickness being less than the first thickness. 
 
     
     
       5. The accessory device of  claim 4 , further comprising:
 a first layer covering an exterior of the shell; 
 a second layer covering an interior of the shell; 
 a rigid filler in the opening, the rigid filler covered by the first layer and the second layer. 
 
     
     
       6. The accessory device of  claim 5 , wherein the second layer is indented such that the second layer is partially in the opening. 
     
     
       7. The accessory device of  claim 1 , further comprising a third segment connected to i) the first segment by a first folding region, and ii) the second segment by a second folding region, the third segment foldable with respect to the first segment and the second segment based upon the foldable region and the second foldable region, respectively, wherein the third segment combines with the first segment and the second segment to form the three dimensional support structure. 
     
     
       8. An accessory device for an electronic device, the accessory device comprising:
 a rear cover comprising a chamber having a size and shape in accordance with the electronic device; 
 a front flap configured to overlay the electronic device in a closed position; and 
 a hinge coupled with the front flap and the rear cover to allow the front flap to rotate with respect to the rear cover; and 
 a first magnetic element and a second magnetic element, wherein the first magnetic element and the second magnetic element are embedded in the hinge, and wherein in the closed position, the first magnetic element magnetically couples with the second magnetic element to maintain the front flap positioned over the rear cover. 
 
     
     
       9. The accessory device of  claim 8 , wherein:
 the rear cover comprises a shell, the shell comprising a rear wall and sidewalls that combine with the rear wall to define the chamber, and 
 the sidewalls comprise a lip. 
 
     
     
       10. The accessory device of  claim 9 , wherein the sidewall comprises a first material, and wherein the lip comprises a second material different from the first material. 
     
     
       11. The accessory device of  claim 9 , wherein the lip comprises a rigid material embedded in the lip. 
     
     
       12. The accessory device of  claim 11 , wherein the rigid material comprises fiber strands. 
     
     
       13. The accessory device of  claim 9 , first comprising a first layer and a second layer, wherein the first layer and the second layer combine to cover the rear cover, the front flap, and the hinge. 
     
     
       14. The accessory device of  claim 13 , wherein in the shell comprises an opening in a location corresponding to a button of the electronic device, the opening having a rigid filler covered by the first layer and the second layer, wherein a force applied to the rigid filler causes a depression event of the button. 
     
     
       15. A method for assembling an accessory device suitable for use with an electronic device, the method comprising:
 forming a shell comprising a bottom wall and sidewalls extending from the bottom wall to define cavity having a size and shape in accordance with the electronic device; 
 forming a lip continuously along the sidewalls to define a planar surface, the lip capable of retaining the electronic device; and 
 embedding a rigid material in the lip; and 
 connecting a front flap connected with the shell, the front flap having a size and shape capable of folding onto the planar surface, the front flap comprising:
 a first segment carrying a first magnetic element, 
 a second segment carrying a second magnetic element, and 
 a third segment connected to i) the first segment by a first folding region, and ii) the second segment by a second folding region, wherein the first segment and the second segment are capable of folding along the first folding region and the second folding region, respectively, causing the first magnetic element to magnetically couple with the second magnetic element and forming a three dimensional support structure based upon the first segment, the second segment, and the third segment. 
 
 
     
     
       16. The method of  claim 15 , wherein embedding the rigid material in the lip comprises embedding fiber strands in the lip. 
     
     
       17. The method of  claim 15 , wherein forming the shell comprises a molding a first material, and wherein forming the lip continuously along the sidewalls comprises molding a second material different to the first material, the second material different from the first material. 
     
     
       18. The method of  claim 15 , wherein forming the shell comprises:
 forming an opening for an operational component of the electronic device, 
 forming the shell of a first thickness, and 
 forming the shell of a second thickness around the opening, the second thickness different from the first thickness. 
 
     
     
       19. The method of  claim 18 , wherein the second thickness is less than the first thickness. 
     
     
       20. The method of  claim 18 , further comprising:
 covering an exterior of the shell with a first layer; 
 covering an interior of the shell with a second layer; 
 inserting a rigid filler in the opening, the rigid filler covered by the first layer and the second layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/443,040, filed May 14, 2015, of the same title, now U.S. Pat. No. 9,419,669 issued Aug. 16, 2016, which is a U.S. national stage application under 35 U.S.C. § 371 claiming priority to PCT Application No. PCT/US2014/052869, filed Aug. 27, 2014, entitled “CASE FOR AN ELECTRONIC DEVICE AND MANUFACTURING METHODS FOR MAKING A CASE” by Smith et al., now WO 2015/034719 published Mar. 12, 2015, which claims the benefit of priority: (i) U.S. Provisional Application No. 61/893,667, filed Oct. 21, 2013, entitled “CASE FOR AN ELECTRONIC DEVICE” by Smith et al.; (ii) U.S. application Ser. No. 14/258,951, filed Apr. 22, 2014, entitled “FEATURES AND MANUFACTURING METHODS FOR A CASE FOR A PORTABLE ELECTRONIC DEVICE” by Balaji et al.; and (iii) U.S. Provisional Application No. 61/873,748, filed Sep. 4, 2013, entitled “FEATURES AND MANUFACTURING METHODS FOR A CASE FOR A PORTABLE ELECTRONIC DEVICE” by Balaji et al., the contents of each are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The described embodiments relate generally to an accessory of an electronic device. In particular, the present embodiments relate to features of the accessory unit and manufacturing methods for making the accessory unit. 
     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. 
     Also, as advancements are made in the field of consumer electronic devices, development of associated accessory units also occurs. 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. 
     SUMMARY 
     In one aspect, an accessory unit is described. The accessory unit may include a front flap which includes several segments, an inner layer and an outer layer disposed on either side of the several segments. In some embodiments, the inner and outer layers allow the front flap to fold in regions between the several segments. The accessory unit may also include an end region. The accessory unit may also include a rear cover coupled to the front flap. The rear cover may include a shell forming a recessed region. In some embodiments, the inner layer and the outer layer bonded on either side of the shell. The rear cover may also include a lip mechanically coupled along a periphery of the shell, wherein the lip is formed from a material more rigid than the shell and is configured to retain an electronic device within the recessed region of the shell. In some 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 recessed region and an open configuration in which the opening to the recessed region is at least partially uncovered. 
     In another aspect, a method for forming a rear cover of an accessory unit is described. The method may include shaping a recessed cavity from a composite material. The method may also include molding a lip along a periphery of the recessed cavity, wherein the lip is formed from a material capable of co-curing with a resin used in the recessed cavity. The method may also include placing a unidirectional fiber within the lip, wherein the unidirectional fiber extends around a periphery of the lip. 
     In another aspect, a method for forming a button assembly on an accessory unit is described. In some embodiments, the accessory unit includes a structural shell, an inner cosmetic layer, and an outer cosmetic layer. The method may include creating a chamfered opening in the structural shell. In some embodiments, the chamfered opening is aligned with a button on an electronic device configured to rest within the accessory unit. The method may further include positioning a rigid filler within the chamfered opening. In some embodiments, the rigid filler has a chamfered edge corresponding to the chamfered opening in the structural shell. The method may further include bonding the inner cosmetic layer and outer cosmetic layer on either side of the structural shell, wherein no adhesive is allowed to contact the rigid filler. In some embodiments, the rigid filler is configured to transfer a force exerted on the outer layer to a button disposed on the electronic device. 
     In another aspect, a button assembly for depressing a button on an electronic device through an accessory having a structural shell, an inner cosmetic layer bonded to the structural shell, an outer cosmetic layer bonded to the structural shell is described. The button assembly may include an opening in the structural shell. The button assembly may also include a region of reduced thickness in the structural shell surrounding the opening in the structural shell. The button assembly may also include an outer button over-molded onto the region of reduced thickness in the structural shell and protruding through the opening in the shell. In some embodiments, the outer button is disposed between the inner cosmetic layer and the outer cosmetic layer. In some embodiments, the outer button is configured to transfer a forced exerted on the outer cosmetic layer to a button disposed on the electronic device. 
     In another aspect, a case for a portable electronic device having a housing and a display assembly carried by the housing is described. The case may include a recessed portion and a lip portion. The recessed portion may include a side wall. The lip portion may be integrally formed with the recessed portion. The recessed portion and the lip portion may cooperate to define a chamber. The lip portion may further include a resilient material and be configured to retain the portable electronic device within the chamber. The lip portion may further include an edge having a shape that defines an opening suitable for receiving the portable electronic device. While receiving of the portable electronic device into the chamber, the edge may directly engage the housing. The sidewall and the lip portion may cooperate to provide an affirmative feedback indicating that the portable electronic device is fully secured within the chamber. 
     In another aspect, a method of forming a rear cover configured to receive an electronic device is described. The method may include applying an adhesive to an inner portion of a shell and an outer portion of the shell. The shell may include a lip portion, and the shell may be configured to receive the electronic device. The method further includes applying a first layer to a central portion disposed on the inner portion of the shell. The first layer may be configured to engage the inner portion and the lip portion. The first layer may also include an outer peripheral region. The method further includes expanding the inner layer toward an inner surface of the shell. The inner surface extends around a perimeter of the shell. The method may further include applying a second layer to the outer portion of the shell. The second layer may include an outer peripheral region, and may be configured to engage the lip portion and the outer portion. The outer peripheral region of the second layer may be configured to engage the outer peripheral region of the inner portion. The method may further comprise curing the adhesive. 
     In another aspect, a method of forming a front cover for an electronic device is described. The may include providing a fabric layer having a top surface and a bottom surface opposite the top surface. The fabric layer may also include a first thickness measuring from a vertical distance between the top surface and the bottom surface. The method may further include positioning the fabric layer such that the fabric layer includes a first elevated portion and a second elevated portion. A non-elevated portion of the fabric layer may extend between the first elevated portion and the second elevated portion. The method may further include applying a first cut on the top surface at the first elevated portion thereby forming a first cut portion. The method may further include removing the first elevated portion. 
     Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary 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 and this summary, be within the scope of the embodiments, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1A  shows a perspective view of an accessory unit comprising a front flap and a rear cover with the front flap in an open configuration; 
         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. 3  illustrates an exploded perspective view of the accessory unit of  FIG. 1A  in the open configuration; 
         FIG. 4A  shows a cross-sectional view of the shell and lip of the rear cover; 
         FIG. 4B  shows a cross-sectional view of the shell with a separate lip component; 
         FIG. 4C  shows a cross-sectional view of the shell and lip of the rear cover with an added fiber reinforcement in the lip portion; 
         FIG. 5  shows an apparatus for placing a fiber in the lip portion during the curing process; 
         FIG. 6  shows a flow chart depicting a process for molding a lip onto a shell; 
         FIG. 7  shows a flow chart depicting a process for molding a lip onto a shell with a fiber held within the lip; 
         FIG. 8A  shows a perspective view of a shell with several blind holes for openings; 
         FIG. 8B  shows a cross-sectional of the shell of  FIG. 8A ; 
         FIG. 8C  shows a cross-sectional of the shell of  FIG. 8A ; 
         FIG. 9  shows a flow chart depicting a process for creating a hole through an accessory unit while displaying a minimal amount of shell; 
         FIG. 10A  illustrates a process for trimming an excess amount of covering material from an accessory unit; 
         FIG. 10B  shows a cross-sectional view of a shell with inner and outer layers bonded and trimmed; 
         FIG. 11A  illustrates a process for curing an adhesive using a plug; 
         FIG. 11B  illustrates a process for curing an adhesive using a rolling heater; 
         FIG. 11C  illustrates a process for curing an adhesive using a deformable plug; 
         FIG. 12A  shows a cross-sectional view of a hinge mechanism utilizing two rigid stiffeners; 
         FIG. 12B  shows a cross-sectional view of a hinge mechanism utilizing magnets; 
         FIG. 13A  shows a cross-sectional view of a button assembly using a rigid filler to depress a button; 
         FIG. 13B  shows a cross-sectional view of a button assembly using an over-molded outer button to depress a button; 
         FIG. 13C  shows a flow chart depicting a process for creating a button assembly; 
         FIG. 13D  shows a flow chart depicting a process for creating a button assembly; 
         FIG. 14  illustrates a cross sectional view of the accessory unit shown in  FIG. 1A  in the open configuration; 
         FIG. 15  illustrates a perspective view of the accessory unit of  FIG. 14  with the front flap in a closed configuration; 
         FIG. 16  illustrates a cross sectional view of the accessory unit of  FIG. 15  with the front flap in a closed configuration; 
         FIGS. 17A-17C  illustrate cross-sectional side views various embodiments of shells; 
         FIGS. 17D-17G  illustrate cross-sectional side views schematically showing a method for forming a rear cover portion of an accessory unit; 
         FIGS. 18A-18D  illustrate a side cross sectional views showing various features relating to sidewalls of an accessory unit; 
         FIGS. 19A-19E  illustrate cross sectional views showing a method for skiving a piece of fabric; 
         FIG. 20  illustrates a block diagram representing a method for assembling an accessory unit; 
         FIGS. 21A-21D  illustrate various embodiments of hybrid shells suitable for use as a shell within an accessory unit; 
         FIG. 22  is a block diagram of an arrangement of functional modules utilized by a portable media device; and 
         FIG. 23  is a block diagram of an electronic device suitable for use with the described embodiments. 
     
    
    
     Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings may be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     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 in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, 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 described embodiments. 
     Accessory units are commonly used in conjunction with consumer electronic devices. Some accessory units are configured to protect consumer electronic devices. For example, cases may be employed to partially or fully surround a consumer electronic device such that the consumer electronic device is protected from damage. By way of further example, stands for consumer electronic devices may be configured to prop up the consumer electronic devices such that they may be conveniently positioned for interaction therewith. Another accessory unit can take the form of a foldable cover that can be detachably connected to, for example, a tablet computer. Some accessory units can be configured to move between multiple configurations, including one configuration in which the accessory unit functions as a cover and another configuration in which the accessory unit functions as a stand. 
     These and other embodiments are discussed below with reference to  FIGS. 1-15 . 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,  FIGS. 1A and 1B  illustrate an embodiment of an accessory unit  100  according to the present disclosure. As illustrated, the accessory unit  100  can comprise a front flap  200  and a rear cover  300 . The front flap  200  can include a plurality of segments  202  and a folding region  204  positioned between each of the segments. The folding regions  204  can be configured to allow the segments  202  to fold with respect to each other. The front flap  200  can also include an end region  206 . The end region  206  can hingedly couple 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 can 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 can 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 . In some embodiments, some of the magnets can also be arranged to form a magnetic attraction with an attractable magnetic element disposed within at least one insert. In one embodiment, the attractable magnetic elements 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 addition, the spacing between folding regions  204  can be configured to allow segments  202  to be arranged into a triangular support structure. This triangular support structure can support the electronic device at an angle that allows a user to operate the device without having to support the device with hands. In one embodiment, the triangular support structure can be formed by placing one or more magnets in segments  202  configured to hold the segments together in a desired shape. In another embodiment, friction can be sufficient to maintain the triangular structure without the need for magnets. 
     The rear cover  300  can include a recessed portion  302  and lip  304 . The recessed portion  302  can include a plurality of sidewalls  306   a - d  (collectively, “ 306 ”) and a bottom wall  308  that define a chamber  310 . The recessed portion  302  can include one or more apertures  312   a - e  (collectively, “ 312 ”) and/or one or more embossed portions  314   a - b  (collectively, “ 314 ”). The lip  304  can 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 composite material. Additionally, the lip  304  can be formed from a material that is more rigid than the composite material of the recessed portion  302 . In this regard, the lip  304  of the rear cover  300  can be configured to retain a consumer electronic device in the chamber  310 , as discussed in detail below. Also, 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 a consumer electronic device (not shown). 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 . In one embodiment, apertures  312  can be punched into a thermoplastic shell that provides structure to accessory unit  100 . A liquid crystal polymer fiber can be added around apertures  312  to reinforce apertures  312 . In one specific embodiment, a 70 micron thick layer of liquid crystal polymer fiber can be utilized to provide durability to apertures  312 . One specific type of liquid crystal polymer fiber that can be utilized for such a purpose is VECTRAN® fiber. 
     The lip portion  304 , including lip portions  304   a - d  as shown in  FIG. 1A , can be integrally formed with the recessed portion  302  and extend about an opening  316  of the chamber  310 . It should be noted that in alternate embodiments lip portion  304  can be a separate rigid frame member in contact with recessed portion  302 . 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 lip portion  304  may be formed from a material that is more rigid than the flexible material of the recessed portion  302 . In this regard, the lip portion  304  of the rear cover  300  may be configured to retain a consumer electronic device in the chamber  310 , as discussed in detail below. In some embodiments, the rigidness of lip portion  304  can be due substantially to a thickness of lip portion  304  with respect to recessed portion  302 . 
     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 lip  304  and the front flap defines a substantially planar configuration. In addition, as was described above, the front flap  200  can also be placed in a triangular configuration when in the open position to form a stand for the electronic device. 
     As illustrated in  FIG. 2A , the edges  210  of the front flap  200  can contact the lip  304  when front flap  200  is in the closed configuration. Accordingly, the front flap  200  can define a substantially planar configuration when moved to the closed configuration. In this regard, the end segment  208  can 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  can bend to enable end region  206  to function as a hinge. 
     In some embodiments, as illustrated in  FIG. 2A , the lip  304  can extend outwardly beyond the edges  210  of the front flap  200 . In this regard, the lip  304  can function to protect a consumer electronic device received in 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 lip  304  can extend to the same dimensions, or the edges of the front flap can extend beyond the lip  304 . 
     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. 3  illustrates an exploded view of one embodiment of the accessory unit  100  in the open configuration. As illustrated, the accessory unit  100  can 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  can 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  can be at least partially integrally formed in one embodiment, providing a pleasing, continuous appearance to the visible surfaces of accessory unit  100 . However, the rear cover  300  and the front flap  200  can be formed from separate materials in other embodiments. 
     The material(s) defining the inner layer  102  and the outer layer  104  can be the same or different. In one embodiment, both the inner layer  102  and the outer layer  104  can be formed from a microfiber material, leather-like material, or any other technically feasible material. In another embodiment the inner layer  102  can include a microfiber material and the outer layer  104  can include poly urethane type materials such as PUK. In this regard, the inner layer  102  and the outer layer  104  can 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  can also be configured to passively clean the consumer electronic device, which may come into contact with the inner layer while held therein. 
     In some embodiments, the accessory unit  100  can further include one or more additional materials between the inner layer  102  and the outer layer  104 . For example, the accessory unit  100  can 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, can be configured to define the structure of the segments  202  of the front flap  200 . In turn, the areas between the panels  106  can 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  can further include one or more magnetic elements in the front flap  200 . In one embodiment, one or more magnetic elements  108  can be configured to interact with an attachment feature of a consumer electronic device received in rear cover  300 . For example, the magnetic elements  108  can 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  can 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 can include a Hall Effect sensor. 
     As an example, the Hall Effect sensor can respond to the presence (or absence) of a 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 a 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. 
     The accessory unit  100  can further include one or more end panels  112  between the inner layer  102  and the outer layer  104 , which can be configured to define the structure of a portion of the end region  206  at the end segment  208 . The end panels  112  can 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, leather, or any other suitable material) can 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  can provide rigidity and stiffness. In some embodiments, the front flap  200  can also include a reinforcement bar  114 . The reinforcement bar  114  can 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  and  210   b  of the front flap  200 . Accordingly, the reinforcement bar  114  can be formed from a relatively rigid material such as plastic, steel, carbon fiber, fiberglass, etc. 
     The accessory unit  100  can also include shell  118 . Shell  118  can be positioned between inner layer  102  and outer layer  104  in the area of rear cover  300 , and can provide stiffness to rear cover  300 . Shell  118  can be formed from a variety of materials, including thermoplastics, composites, and the like. In the described embodiments, shell  118  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. 
     In addition, shell  118  can include a variety of openings configured to provide access to various buttons, camera holes, speaker ports, etc. In some embodiments, speaker cover  116  can be included between shell  118  and inner layer  102  or outer layer  104 , including perforations to allow sound to escape from speakers included in the electronic device. Shell  118  can be attached to inner layer  102  and outer layer  104  using a variety of adhesives. In one embodiment, a heat activated adhesive can be used to attach both inner layer  102  and outer layer  104  to shell  118 . However, any technically feasible adhesive can be used to form a reliable connection. Lip  304  can be provided around a periphery of shell  118  to provide structural stiffness to rear cover  300  and an overhang for retention of the electronic device. In some embodiments, lip  304  can be integrated into shell  118 . In other embodiments, lip  304  can be formed as a separate component and attached to shell  118  during an assembly process. More detail regarding lip  304  and the interface between lip  304  and shell  118  are described below. 
     The front flap  200  can include inner and outer adhesive layers  120  and  122  that bond the layers of material defining the front flap together. In particular, the outer adhesive layer  120  can 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  can bond the inner layer  102  to the reinforcement bar  114 , the panels  106 , and the end panel  112 . Accordingly, the adhesive layers  120  and  122  can laminate the layers and components comprising the front flap  200  together. 
     In some embodiments the adhesive layers  120  and  122  can comprise a thermoplastic adhesive, such as a thermoplastic urethane adhesive, or a thermoplastic nylon adhesive. Such thermoplastic adhesives can 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 can 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 can be controlled. For example, in one embodiment, as the thermoplastic adhesive melts the adhesive can seep into adjacent porous layers of material, forming a bonded structure. Longer periods of heating can result in increased infusion into the material and can create a more rigid structure. 
     In some embodiments, the flexibility of front flap  200  can also be controlled by locally thinning regions of inner layer  102  and outer layer  104 . This can be particularly important when inner and outer layers  102  and  104  are formed from a relatively stiff material such as leather. In one embodiment, the local thickness of layers  102  and  104  can be reduced by running an abrasion tool such as a horizontal sanding wheel along a non-visible surface of layers  102  and  104  in regions  204  prior to assembly. In other embodiments, the same effect can be achieved using a laser or splitting machine. 
     Furthermore, some embodiments of accessory unit  100  can include features configured to retain flexibility of the end region  206  of the front flap  200 . In the embodiment of the accessory unit  100  illustrated in  FIG. 3 , the inner and outer adhesive layers  120  and  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  can include tab  122 ′ that extends across the end region  206  proximate the side edges  210   a  and  210   b  of the front flap  200 . In particular, tab  122 ′ can 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 can be bonded at first and second longitudinal ends  206   a  and  206   b  of the end region  206  and decoupled therebetween due to tab  122 ′ bonding 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  can function as a hinge as previously described. Other embodiments of the hinge between front flap  200  and rear cover  300  are described below. 
       FIG. 4A  shows a cross-sectional view of shell  118  and lip  304 , demonstrating how lip  304  can retain electronic device  402  within accessory unit  100 . The materials used for forming shell  119  and lip  304  can be chosen to provide rear cover  300  with mechanical properties sufficient to securely retain electronic device  402  within rear cover  300 , while at the same time retaining enough flexibility to allow electronic device  402  to be inserted and removed numerous times without undue exertion by an end-user or potentially damaging accessory unit  100  or electronic device  402 . In order to insert and remove electronic device  402 , both shell  118  and lip  304  can deflect outwards in direction  404 . In one embodiment, electronic device  402  can include chamfer  412  around a periphery of an upper surface. When this is the case, the shape of shell  118  and lip  304  can be configured to provide two points of contact at both edges of the chamfer. The result of this two point engagement is a “snap” experience when electronic device  402  is fully engaged within rear cover  300 . This snap can provide an enhanced user experience and assist in alerting the user that electronic device  402  is fully retained within rear cover  300 . 
     In one embodiment, shell  118  and lip  304  can be formed from the same material. The material used can include thermoplastics, fiber reinforced plastics, polymers, and the like. However, there can be several disadvantages to forming both shell  118  and lip  304  from the same material. First, it can be difficult to locate a material that possesses the mechanical properties necessary to protect and hold in place electronic device  402  while simultaneously having the flexibility to allow electronic device  402  to be easily inserted and removed. Second, the undercut formed by lip  304  can complicate the molding process when shell  118  and lip  304  are formed as a single part, necessitating the use of sliders or other moving parts in the mold. 
     The above mentioned difficulties can be removed by forming shell  118  and lip  304  from different materials.  FIG. 4B  shows an alternative embodiment in which shell  118  and lip  304  are made from different materials and joined during an assembly process. For example, shell  118  can be formed from a glass-fiber reinforced plastic while lip  304  can be formed from a thermoplastic material. The combination of different materials can provide a satisfactory combination of mechanical strength and flexibility to both protect electronic device  402  and allow for easy insertion and removal. In one embodiment, the resin used in shell  118  can be closely matched to the thermoplastic used in lip  304 , such that both resins can cure simultaneously and form a bond along surface  408 . More detail regarding this process is shown in  FIG. 6 . 
       FIG. 4C  shows yet another embodiment of shell  118  and lip  304 . Similar to the embodiment shown in  4 B, shell  118  and lip  304  can be formed from separate materials. For example, shell  118  can be formed from a glass-fiber reinforced plastic while lip  304  can be formed from a thermoplastic. However, lip  304  can also include one or more strands of fiber  410  along the length of lip  304 . The added fibers can increase the rigidity of lip  304 . Fibers  410  can be selected from a number of fibers including Kevlar, glass fibers, carbon fibers, and the like. In one embodiment, fiber  410  can be introduced in the assembly during the curing process for shell  118  and lip  304 , allowing all three components to cure simultaneously. In other embodiments, fiber  410  can be added to an outer surface of lip  304  after lip  304  has been cured. In this case, fiber  410  can be attached to lip  304  using adhesives, solder, or any other technically feasible means. An apparatus for inserting fiber  410  into lip  304  during the curing process is shown in  FIG. 5  and a process for including fiber  410  is described in  FIG. 7 . 
       FIG. 5  shows apparatus  500  for including fiber  410  in lip  304  during the curing process. Shell  118  can placed in a mold and an over-mold for forming lip  304  can be placed over shell  118 . Corner guides  502  can be placed along interior corners of lip  304  and fiber  410  can be wrapped around an outer surface of the corner guides  502 . Pegs  506  and  508  can be used to direct fiber  410  away from apparatus  500  and tighten fiber  410  until it is taut. The combination of corner guides  502  and pegs  506  and  508  can hold fiber  410  in place while lip  304  is cured. As a result, fiber  410  becomes an integral part of lip  304  and can greatly increase the rigidity of lip  304 . 
       FIG. 6  shows a flow chart depicting process  600  for simultaneously curing a shell and a lip for an accessory unit. In step  602 , a glass-fiber reinforced composite can be molded into the shape of the shell. In other embodiments, the shell can be molded from other materials such as thermoplastics. The resin used in the molding process can either be added at this time or be pre-impregnated in the fibers. In still other embodiments, fibers other than glass can be used in the composite framework, including Kevlar, carbon fiber, and the like. Next, in step  604 , the curing process for the shell can begin. This can include heat, time, UV-curing, or any other technically feasible means of curing. While the curing process for the shell is still in progress, in step  606 , the lip can be molded over the edge of the shell. The lip can be formed using a resin or thermoplastic with properties similar to the resin used in the shell. This can ensure that a strong bond is formed between the shell and lip. Finally, in step  608 , the shell and lip can be allowed to cure together and form one part. 
       FIG. 7  shows a flow chart depicting process  700  for including one or more strands of fiber in the lip of the rear cover. In step  702 , a glass-fiber reinforced composite can be molded into the shape of the shell. In other embodiments, the shell can be molded from other materials such as thermoplastics. The resin used in the molding process can either be added at this time or be pre-impregnated in the fibers. In still other embodiments, fibers other than glass can be used in the composite framework, including Kevlar, carbon fiber, and the like. Next, in step  704 , an over-mold for forming the lip can be positioned over the edge of the shell. Then, in step  706 , one or more strands of fiber can be passed through the mold for the lip and tightened. In some embodiments, an apparatus with corner guides and tightening pegs such as the apparatus depicted in  FIG. 5  can be used to align the fibers properly within the mold. Next, in step  708 , the lip material can be injected into the lip mold. The lip material can include a resin or thermoplastic with properties similar to the resin used in the shell. Finally, in step  710 , the shell, lip, and fiber strands can be allowed to cure together and form one unified part. 
       FIG. 8A  shows shell assembly  800 , demonstrating a method for creating through holes in accessory unit  100  while minimizing the degree to which the shell is visible to the user. Accessory unit  100  can include a variety of through openings allowing the electronic device to be exposed to the outside environment in limited areas. These can include openings for cameras, headphone jacks, speakers, microphones and the like. If these openings are created through inner layer  102 , shell  118 , and outer layer  104 , then a significant portion of shell  118  can be visible to the user around an interior of the opening. Often times, shell  118  can be a different color than inner layer  102  and outer layer  104 , resulting in an opening that is not aesthetically pleasing.  FIGS. 8A-8C  demonstrate how this discontinuity can be minimized or eliminated. Areas  802  can represent regions in which through holes are needed for a camera, headphone jack, or other type of opening. Shell  118  can be drilled or machined to create a blind hole in these regions. For example, if the total thickness of shell  118  is approximately 0.4 mm, regions  802  can be machined down to a thickness of 0.2 mm. It should be noted that these numbers are representative and any percentage of the thickness of shell  110  can be removed during this process. 
     Referring to  FIG. 8B , a cross-sectional view of region  802  is shown after inner layer  102  and outer layer  104  have been affixed and the through hole has been cut. Inner layer  102  can follow the contour of shell  118  as the thickness is reduced from the normal thickness to that of the blind hole. As such, the visible portion of shell  118  is decreased from distance d 1  to distance d 2 . Often times, this reduction can reduce the thickness of shell  118  to the point where it is not visible to the human eye upon casual inspection of accessory unit  100 .  FIG. 8C  shows another embodiment in which a through hole is used in place of a blind hole in regions  802 . In this case, inner layer  102  and outer layer  104  are bonded directly to each other in the area surrounding the final through hole. This method can ensure that shell  118  is completely invisible to the user, but offers less structural support around the opening. For this reason, the technique shown in  FIG. 8B  is preferable when used around openings in higher stress areas of accessory unit  100 . 
       FIG. 9  shows a flow chart depicting process  900  for minimizing an amount of visible shell in an opening through an accessory unit. In step  902 , a blind hole is drilled or machined in an area where an opening is desired. The blind hole should be larger than the desired opening. Preferably, the blind hole should be placed on a non-visible side of the accessory unit. However, the hole can be placed on either side if so desired. The depth of the hole can be approximately half the thickness of the shell or any other suitable depth. Next, in steps  904  and  906 , the inner and outer layers are bonded on both surfaces of the shell. Finally, in step  908 , the desired opening is cut through the inner layer, shell, and outer layer at the center of the blind hole. The reduced thickness of the shell around the periphery of the opening can make the appearance of the opening more aesthetically pleasing to the user. 
       FIGS. 10A and 10B  show a cross-sectional view of accessory unit  100  as inner layer  102  and outer layer  104  are applied to shell  118  and lip  304 . In some embodiments, inner layer  102  and outer layer  104  can make up one piece of material that wraps around the entirety of accessory unit  100  and meets along one seam. Inner and outer layers  102  and  104  can be formed from a variety of different fabrics and materials. Preferably, layers  102  and  104  can be formed low recovery or “high set” fabrics that tend to remain in a deformed state when they are stretched to form around the contours of an object such as accessory unit  100 . In addition, it can be preferable to use fabrics that bond well with adhesives. In some embodiments, a primer can be placed on either shell  118  or inner and outer layers  102  and  104  to increase the stiction of the bond between the two. 
     Inner layer  102  and outer layer  104  can be bonded using any suitable adhesive. In one embodiment, thermoplastic adhesives can be used. However, the use of thermoplastic adhesives can be problematic with some materials due to the high heat needed to cure thermoplastic adhesives. For example, the temperatures needed to cure a thermoplastic adhesive can damage some forms of leather and polyurethanes. In another embodiment, thermosetting glues can be used in place of thermoplastic adhesives. Thermosetting glues can cure at temperatures as low as 80 degrees F. and can therefore be more appropriate for use with temperature sensitive materials. As is shown in  FIG. 10A , an excess amount of material can be left after inner layer  102  and outer layer  104  are bonded to shell  118  and lip  304 . The excess material can be removed using diecut  1002  to leave seamless finish  1004  shown in  FIG. 10B . In one embodiment, diecut  1002  can consist of a machined, single sided blade with tolerances sufficient to ensure that a precise cut is made. However, any suitable method for cutting material can be used to trim excess material from inner layer  102  and outer layer  104 . 
       FIGS. 11A-11C  demonstrate methods for curing thermosetting glue around an edge region of rear cover  300 . One problem that can arise when bonding inner layer  102  to shell  118  and lip  304  is maintaining sufficient pressure and heat underneath the overhang formed by lip  304  while the adhesive is curing.  FIG. 11A  demonstrates one method of solving this problem using a heated plug  1102  during the curing process. Plug  1102  can have a shape similar to that of the electronic device accessory unit  100  is designed to accommodate and be formed from a thermally conductive material such as steel, metal, or brass. The combination of heat and pressure under lip  304  can allow inner layer  102  to firmly adhere to shell  118  and lip  304 . 
       FIG. 11B  shows an alternative method of providing heat and pressure using a rotating fixture  1104 . Fixture  1104  has a shape configured to conform to the interior of shell  118  and lip  304 . In addition, fixture  1104  can rotate about axis  1106  and translate around a periphery of shell  118 , providing intermittent pressure and heat during the curing process. Finally,  FIG. 11C  demonstrates yet another method of creating pressure under lip  304 . Deformable material  1108  can be placed within the cavity formed by shell  118 . Deformable material  1108  can be any material capable of deforming in response to pressure such as silicon. Once in place, pressure can be applied along a top surface of deformable material  1108 , causing the portion of deformable material  1108  within shell  118  to expand outwards and fill any crevices. This outward pressure can hold inner layer  102  in place against shell  118  and lip  304  during the curing process. 
     As noted above, front flap  200  can be hingedly coupled to rear cover  300 .  FIGS. 12A and 12B  show various embodiments of means for forming an acceptable hinge mechanism. Inner layer  102  and outer layer  104  are formed from flexible materials and can span between front flap  200  and rear cover  300 , providing means for front flap  200  to rotate between open and closed positions. However, when left as the only connection between front flap  200  and rear cover  300 , inner and outer layers  102  and  104  tend to bend in undesirable directions, causing front flap  200  to misalign with rear cover  300  when in a closed position. Moreover, if inner and outer layers  102  and  104  are overly stiff, front flap  200  can fail to lay flat against rear cover  300  when in a closed position. 
     To correct these issues, two rigid stiffeners  112  can be included between inner layer  102  and outer layer  104  such that the accessory unit  100  folds between the two rigid stiffeners  112  when placed in the closed position. Rigid stiffeners  112  can be formed from any suitably rigid material, including steel, aluminum, plastics, fabric scrims, and the like. Rigid stiffeners  112  can be held in place by the same adhesive that bonds inner and outer layers  102  and  104  together between rigid stiffeners  112  or any other suitable adhesive. In some embodiments, further flexibility can be added to the hinge system by performing a hot press on inner and outer layers  102  and  104  in region  1202  between the two rigid stiffeners  112 . In yet another embodiment, flexibility can be further increased by reducing the thickness of inner and outer layers  102  and  104  in region  1202  using an abrasion tool, laser, or splitting machine prior to assembly.  FIG. 12B  shows another embodiment in which rigid stiffeners  112  are replaced by magnets  1204 . Magnets  1204  can be placed with reversed polarities such that the magnets  1204  attract each other when rotated into the closed position as shown by the arrow. The addition of magnets  1204  can further ensure that front flap  200  lays flat against the electronic device when placed in the closed position. 
       FIGS. 13A and 13B  demonstrate multiple embodiments for allowing a user to access buttons on the electronic device through accessory unit  100  without the need for a through hole. In  FIG. 13A , electronic device  1302  includes button  1304  that can be accessed by the user without removing electronic device  1302 . The shown portion of rear cover  300  includes inner layer  102 , outer layer  104 , and shell  118 . Chamfered opening  1308  can be created in shell  118  aligned with button  1304 , and the space created by chamfered opening  1308  can be filled with rigid filler  1306  during the assembly process. Rigid filler  1306  can be formed from any suitably rigid material, including aluminum, steel and plastic. When the user depresses outer layer  104  above button  1304 , the force is transferred through outer layer  104  to rigid filler  1306 . Rigid filler  1306  then transfers the force through inner layer  102  and depresses button  1304 . 
       FIG. 13B  demonstrates another embodiment providing access to button  1304  on electronic device  1302 . Similar to  FIG. 13A , the shown portion of rear cover  300  includes inner layer  102 , outer layer  104 , and shell  118 . However, shell  118  contains through hole  1314  surrounded by blind hole  1312 , where blind hole  1312  is larger than through hole  1314 . The thinned section of shell  118  created by blind hole  1312  can be used as a bonding area to over-mold outer button  1310 . Outer button  1310  can be formed from any compression moldable material capable of forming a button shape such as silicon. In other embodiments, a hard filler can also be embedded in the over-molded material similar to the embodiment described in  FIG. 13A . When the user presses on outer layer  104 , the force is transferred through outer button  1310  and inner layer  102  to depress button  1304 . 
       FIG. 13C  shows a flow chart depicting process  1320  for creating a button assembly along the lines of  FIG. 13A . In step  1322 , a chamfered opening is created in a shell. The opening can be circular or any other feasible shape. Preferably, the opening can have a shape roughly equal to that of the button on the electronic device that the button assembly is configured to depress. In step  1324 , a rigid filler is placed within the chamfered opening. The rigid filler can have a chamfered edge as well, with the sides aligned to interlock with the chamfered opening in the shell. In steps  1326  and  1328 , inner and outer layers are bonded to the shell. However, adhesives should not be placed between the inner and outer layers and the rigid filler, allowing the rigid filler to move freely within the chamfered opening in the shell. Finally, in step  1330 , the rigid filler can be aligned with a button on a corresponding electronic device. When a force is applied to the outer layer, the force can be transferred through the rigid filler and depress the button the electronic device. 
       FIG. 13D  shows a flow chart depicting process  1350  for creating a button assembly along the lines of  FIG. 13B . In step  1352 , an opening is created in the shell. The opening can be circular or any other feasible shape. Preferably, the opening can have a shape roughly equal to that of the button on the electronic device that the button assembly is configured to depress. In step  1354 , the thickness of the shell in a region surrounding the opening can be reduced. The thickness can be reduced through drilling, machining, or any other technically feasible means. Furthermore, the material can be removed from the surface of the shell facing inwards towards the electronic device. Next, in step  1356 , an outer button can be over-molded onto the area of reduced thickness created in step  1354 . The outer button can include a protruding portion that can protrude through the opening in the shell and project outwards from the electronic device. Finally, in steps  1358  and  1360 , the inner and outer layers can be bonded to the shell. When a user depresses the appropriate region of the outer shell, the outer button transfers the resulting force through the inner layer and depresses the corresponding button on the electronic device. 
       FIGS. 14-16  illustrate an embodiment of an accessory unit  1400  according to the present disclosure. As illustrated, the accessory unit  1400  may comprise a front flap  1500  and a rear cover  1600 . The front flap qr 00  may include a plurality of segments  1501   a ,  1501   b ,  1501   c  and a folding region  1504  positioned between each of the segments. The folding regions  1504  may be configured to allow segments  1502  to fold with respect to each other. The front flap  1500  may also include an end region  1506 . The end region  1506  pivotally couples the front flap  1500  to the rear cover  1600 . 
     In some embodiments, each of segments  1501   a ,  1501   b ,  1501   c  can include one or more inserts disposed therein. For example, segments  1501   a ,  1501   b ,  1501   c  can each include a pocket region where the inserts are placed, or alternatively, may be embedded within segments  1501   a ,  1501   b ,  1501   c  (e.g., via insert molding). In embodiments using pockets, the pocket regions have a size and shape to accommodate corresponding inserts. The inserts can have various shapes but are usually shaped to correspond to the overall look of front flap  1500  (e.g., rectangular). The inserts can provide structural support for front flap  1500 . That is, the inserts can provide stiffness to the cover assembly. Accordingly, the inserts may be referred to as stiffeners. The inserts can be formed of rigid or semi-rigid material adding resiliency to front flap  1500 . Examples of materials that can be used include plastics, fiber glass, carbon fiber composites, metals, and the like. Some inserts can be formed of resilient materials that further accommodate other components such as magnetic elements. Magnetic elements can interact with a magnetic sensor disposed within an electronic device (not shown) associated with accessory unit  1400 . Magnetic elements also be arranged to form a magnetic attraction with an attractable magnetic element disposed with at least one insert. In some embodiment, attractable magnetic elements can be formed of steel, or other ferromagnetic material, and take the shape of a thin sheet incorporated within an insert. 
     Front flap  1500  further includes folding regions  1504  that are thinner segments  1501   a ,  201   b ,  201   c  and do not include the inserts thereby allowing front flap  1500  to fold and make front flap  1500  easier to handle. In one embodiment, segments  1501   b , and  1501   c  can be substantially wider than segment  1501   a  in size. In this way, a triangular support structure having appropriate angles can be formed by positioning segments  1501   a ,  1501   b ,  1501   c  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, now U.S. Pat. No. 8,344,836, which is incorporated herein by reference in its entirety. 
     One approach to forming at least one triangular support structure can include segment  201   a  having a plurality of magnets and arranged to fold with respect to segments  1501   b  and  1501   c  in such a way that at least one magnetic element within segment  1501   a  is magnetically attracted to a magnetically active element within segment  1501   c . In this way, segments  1501   a  and segment  1501   c  can be magnetically bound together forming a first triangular support structure. The triangular support structure can be used as a support structure for accessory unit  100 . Accordingly, any electronic component supported by accessory unit  1400  can also be supported. For example, when used as a support, an electronic device having a display and supported by accessory unit  1400  can be placed in such a way that visual content can be displayed at about 75 degrees in relation to a horizontal surface below accessory unit  1400 . In another example, front flap  1500  can be folded to form a second triangular support structure that can be used to position the electronic device in an orientation suitable for using the electronic device as a keyboard. It should be noted, however, that these are only representative examples of many other support structures that can be formed by front flap  1500 . 
     While the flexible material of end region  1506  allows it to pivotally couple front flap  200  to rear cover  1600 , this may also cause misalignment between front flap  1500  and rear cover  1600  in a closed configuration. As shown in  FIG. 16 , a closed configuration refers to front flap  1500  being substantially in contact with rear cover  1600 . To ensure proper alignment between front flap  1500  and rear cover  1600  in a closed configuration, some embodiments include end panels  1508  in end region  1506 . End panels  1508  may be configured to strengthen the end region  206  such that the end region  1506  maintains alignment of outer edges  1510   a - c  (collectively, “ 1510 ”) of the front flap  1500  with respect to the lip portion  1604  of the rear cover  1600 . End panels  1508  could be made of fiberglass, steel, carbon fiber, plastic, or combination thereof. In some embodiments, end segments  1508  can have a thickness that prevents them from showing through to a cosmetic surface of accessory unit  1400 . In this way, end panels  208  can provide rigidity for the pivotal coupling between front flap  1500  and rear cover  1600  without affecting a cosmetic appearance of accessory unit  1400 . 
     In  FIG. 15 , end region  1506  can include a material that is flexible and which thereby allows end region  1506  to bend. However, as a result of employing a flexible material in end region  1506 , without end segments  1608  front flap  1600  can tend to bend relative to the rear cover  1600  at end region  1506  in undesirable directions other than about a major axis  1512  through end region  1506  under certain circumstances. In this regard, end segments  208  can be configured to prevent misalignment of outer edges  1510  of front flap  1500  with respect to lip portion  1604  when the accessory unit is subjected to forces in directions other than perpendicular to a major axis  1512  through the end region  1506 . 
     Referring to  FIG. 15 , outer edges  1510  of front flap  1500  may contact lip portion  1604  when the front flap  1500  is in the closed configuration. Accordingly, front flap  1500  may define a substantially linear configuration when moved to the closed configuration. In this regard, end segments  1508  can be substantially coplanar with the other segments  1501   a ,  1501   b ,  1501   c  and the folding regions  1504  of the front flap  1500  when the front flap  1500  is in the closed (or folded) configuration. However, a portion of end region  1506  adjacent the end segments  1508  bends to enable the end region  1506  to function as a hinge, as noted above. 
     In some embodiments, as illustrated in  FIG. 15 , lip portion  1604  may extend outwardly beyond the outer edges  1510  of front flap  1500 . In this regard, lip portion  1604  may function to protect a consumer electronic device received in the chamber  1610  (referred to in  FIG. 16 ) in rear cover  1600  from damage to the edges of the consumer electronic device when dropped or otherwise subjected to impact. However, in other embodiments, the outer edges  1510  of the front flap  1500  and the lip portion  1604  may extend to the same dimensions, or the outer edges  1510  of the front flap  1500  may extend beyond the lip portion  1604 . When used as a structural element, lip portion  1604  includes material having mechanical properties sufficient to retain the consumer electronic device within chamber  1610  of rear cover  1600 . Moreover, in addition to the ability to retain the consumer electronic product within chamber  1610 , lip portion  1604  also retains enough flexibility to allow the consumer electronic device to be inserted and removed from chamber  1610  numerous times without undue exertion by an end-user, a potentially damaged accessory unit  1400 , or the consumer electronic device. 
     The material(s) defining the accessory unit  1500  may vary. In one embodiment, the entire accessory unit  1500  may be formed from a single material. However, as noted above, in other embodiments, it may be desirable to form the accessory unit  1500  from multiple materials to take advantage of differing material properties. 
     As shown in  FIG. 15 , accessory unit  1400  may further include one or more magnetic elements  1408  in front flap  1600 . For example, magnetic elements  1408  disposed within segment  201   a  can be configured to interact with an attachment feature of a consumer electronic device positioned within rear cover  1600 . Magnetic elements  1408  can be magnetically attracted to the attachment feature of the consumer electronic device when accessory unit  1400  is in a closed configuration such that the front flap  1500  is releasably retained in this configuration. The front flap  1500  may further include a magnetic element  1410  configured to interact with a magnetically sensitive circuit embedded in the consumer electronic device configured to detect the presence, absence, or change from presence to absence, or vice versa, of the magnetic element  1410 . For example, the magnetically sensitive circuit may include a Hall Effect sensor. 
     Magnetic elements  1408  and  1410  of accessory unit  1400  can be configured to provide various other types of functionality. For 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 consumer electronic device. Magnetic element  1410  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. The signal can also be used to alter the operating state to a state having functionality suitable for the consumer electronic device being fully covered. 
     In 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  1500  having magnetic element  1410  is removed to the point where the Hall Effect sensor no longer senses the magnetic field of magnetic element  1410 , then the Hall Effect sensor can generate another signal. This other signal can result in the consumer electronic device entering a different operating state consistent with at least a portion of the display being uncovered and viewable. In this state, the functionality 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, and 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, now U.S. Pat. No. 8,344,836, which is incorporated herein by reference in its entirety. 
       FIG. 16  shows accessory unit  1400  in a closed configuration. Further, in other embodiments, rear cover  1600  could be made with an adhesively formed base material, or alternative, rear cover could simply be an inner layer adhesively attached to an outer layer. In the embodiment shown in  FIG. 2B , rear cover  1600  includes shell  118 . Shell  1418  may be formed by a thermoforming process using plastic, compression molding, injection molding, or a combination thereof. Shell  1418  could be made from any rigid material known in the art for making a case for an electronic housing device. In addition to shell  1418 , rear cover  1600  includes inner layer  1402  is attached to an inner surface of shell  1418 , and outer layer  1404  is also attached to shell  1418 . As shown  FIG. 16 , inner layer  1402  and outer layer  1404  generally terminate at one end near lip portion  1604  of rear cover. Inner layer  1402  and outer layer  1404  extend through rear cover  1600  to define an outer periphery of front flap  1600 . Inner layer  1402  and outer layer  1404  generally terminate at another end near reinforcement element  1416 . In some embodiment, reinforcement element  116  can be formed from a relatively rigid material such as plastic, steel, carbon fiber, fiberglass, etc. In the embodiment shown in  FIG. 16 , reinforcement element  1416  includes an adhesive disposed between inner layer  1402  and outer layer  1404 . 
       FIGS. 17A-17G  show a process for forming rear cover portion of an accessory unit. For simplicity, this set of figures omits front flap  1500 .  FIGS. 17A-17C  show various embodiments of shell  1700 . In  FIG. 3A , a thermoformed plastic shell  1700  made of a single material is depicted. A recessed portion  1702  of shell  1700  can have a substantially uniform thickness, while a lip portion  1704  can be integrally formed with recessed portion  1702 . Lip portion  1704  can be injection molded on to recessed portion  1702 , thereby removing any need for a subsequent bonding operation. In another embodiment shown in  FIG. 17B , plastic recessed portion  1702  is compression molded to a lip portion  1706 . In some embodiments, lip portion  1706  is made from reinforced glass fiber. Lip portion  1706  can be constructed by overlaying a number of unidirectional glass fibers in a continuous loop and then forming them in accordance with a geometry of lip portion  1706 . In  FIG. 17C , lip portion  1706  also includes a substantial portion of sidewalls and accordingly, forms a substantial portion of the recessed portion of shell  1700 . Portions of a shell  1700  that include reinforced material (such as reinforced glass fiber) can substantially add to an overall stiffness of shell  1700 . 
       FIG. 17D  shows a first assembly step, which depicts shell  1700  as depicted in  FIG. 17A  and a first layer  1710  (which may also be referred to as an inner layer). In some embodiments, shell  1700  can be a thermoformed plastic shell, a compression molded shell, an injection molded shell, or a combination thereof. In some embodiments, first layer  1710  is a microfiber layer; microfiber layer could further be a preformed microfiber layer. It should be understood that the embodiments shown in  FIGS. 17B and 17C  could also be used in the assembly steps shown in  FIGS. 17D-17G . First layer  1710  can be a preformed microfiber layer. First layer  1710  can be adhesively coupled to a central portion  1709  of recessed portion  1802 . In one embodiment, first layer  1710  can be adhesively coupled to shell  1700  by a thermoplastic adhesive, while in other embodiments a thermosetting adhesive can be utilized. In both cases, shell  1700  and first layer  1710  can be heated to activate the thermal adhesive.  FIG. 17E  shows a second step in which an expanding device is used to press peripheral portions  1711  of first layer  1710  around a lip portion  1704  of shell  1700 , thereby adhesively engaging the peripheral portions of first layer  1710  about lip portion  1704  and along sidewalls of shell  1700 . Because first layer  1710  is preformed to conform with an inside surface of shell  1700 , undue stretching of first layer  1710  can be controlled and avoided. In this way, pin holes can be prevented from forming in first layer  1710 , thereby preventing adhesive and/or a portion of shell  1700  from showing through first layer  1710 . 
     In  FIG. 17F , once first layer  1710  is in adhesive contact with shell  1700  and while an expanding device (not shown) keeps the first layer  1710  under tension, an exposed portion of shell  1700  can be cooled at a controlled rate to establish desired characteristics in an adhesive coupling between first layer  1710  and shell  1700 . For example, in some embodiments, cooling can be varied to provide varying stiffness across recessed portion  1702  and/or lip portion  1704 . In  FIG. 17G , second layer  1712  (also referred to as an outer layer) can be adhesively coupled to an exposed portion of shell  1700 . Second layer  1712  could be made of leather. In one embodiment, the adhesive coupling can be accomplished using a concave fixture to press second layer  1712  against shell  1700 . First end  1713  and second end  1714  of second layer  1712  can be coupled to first end  1716  and second end  1717 , respectively, of first layer  1710 . First layer  1710  and second layer  1712  can come together to form a substantially zero flange design. The phrase “zero flange design” refers to a bonded region of first layer  1710  and second layer  1712  that free of outward protrusion (with respect to shell  1700 ) of first layer  1710  or second layer  1712 . In other words, the region where first layer  1710  is bonded to second layer  1712  extends from shell  1700  a distance approximately similar to a thickness (width) of first layer  1710  or second layer  1712 ). The zero flange design further maintains the bonded relationship between first layer  1710  and second layer  1712 . An example of zero flange design is shown where second end  1714  of second layer  1712  bonds with first layer  1710 . In some embodiments, a slight flange can be formed to increase surface area between the two layers, thereby improving adhesion. It should be noted that ideal fit and finish of an accessory unit is accomplished by tuning an amount of stretch in both first layer  1710  and second layer  1712 . Also, the adhesive may be cured by, for example, radiation (from a light source such as ultraviolet (UV) light) and/or a time lapse sufficient for the adhesive to bond first layer  1710  and second layer  1712  to shell  1700 . Other cooling means are further discussed below. 
       FIG. 18A  shows a cross sectional view of a sidewall of rear cover  1600  having an electronic device  1800  disposed therein. This view shows how lip portion  1604  can act via interference fit to retain consumer electronic device  1800  in chamber  1610 . When electronic device  1900  is inserted into rear cover  1600 , lip portion  304  extends outward in a direction away from electronic device  1900 , then retracts to the original (resting) position once the electronic device  1900  is fully received by the rear cover  1600 . The interference fit can cause an electronic device  1900  to snap into place within an accessory unit due to a geometry of lip portion  1604  not conforming precisely to an outer surface of consumer electronic device  1800 . In other words, the curvature of rear cover  1600  may not completely correspond to the curvature of electronic device  1900 .  FIG. 18A  further illustrates a close-up showing relationship between lip portion  1604  and chamfered portion  1804  of electronic device  1800 . Here, engaging region  1815  of the inner layer  1402  contacts electronic device  1800 . However, edge  1605  of lip portion  1604  is angled such that inner layer  1402  does not contact electronic device  1800 . The area is shown as disengaging region  1816 . Such a configuration contributes to the snap effect during inserting and extracting electronic device  1800  from an accessory unit. It should be understood this relationship between extends around the perimeter of the lip portion  1604  and electronic device  1900 . 
     This feature allows a user to have affirmative confirmation (for example, by hearing a “snap”) that consumer electronic device  1800  is secured within an accessory unit, or when electronic device  1800  is released/removed from an accessory unit. Also, lip portion  1604  can avoid contacting display cover glass  1802 . This allows all of display cover glass  1802  to remain visible, which may be desirable in embodiments in which electronic device  1800  includes a display that extends near the edges of the top surface of electronic device  1800 . 
     In particular, the curvature of rear cover  1600  may not completely correspond to the curvature of electronic device. For example,  FIG. 18A  illustrates a close-up of the relationship between lip portion  304  and chamfered portion  1804  of electronic device  1800 . Here, engaging region  1915  of the inner layer  1402  contacts electronic device  1800 . However, a lower section of lip portion  1604  is angled such that inner layer  1402  does not contact electronic device  1800 . The area is shown as disengaging region  1816 . Such a configuration contributes to the snap effect of inserting and extracting electronic device  1800  from an accessory unit. It should be understood this relationship between extends around the perimeter of the lip portion  304  and electronic device  1800 . 
       FIG. 18B  shows a cross sectional view of a sidewall of rear cover  1600  that includes embossed portion  1714   b . A tactile feel of embossed portion  1714   b  can be enhanced by adding a filling member  1806  suspended between inner layer  1402  and outer layer  1404 . Filling member  1806  could include a plastic member other or a more flexible member such as silicone. In the embodiment shown in  FIG. 18B , embossed portion  1714   b  can correspond to a volume control of an electronic device. A portion of shell  1418  has been removed to allow user interaction with the volume control. In this way filling member  1806  can provide a strong tactile feeling to a user manipulating the volume control. Inner layer  1402  and outer layer  1404  can cause filling member  1806  to hover in position and provide resistance in response to a user actuation. In some embodiments, filling member  1806  can be surrounded by low durometer rubber during an insert molding operation to provide additional spring/flexibility for actuation of the volume control. In other embodiments, additional tactile enhancements can be made. For example, a portion of outer layer  104  that engages filling member  1806  can be made thinner so that there is less compressible material (e.g, less outer layer  1404 ) when a user actuates the volume control. A treatment can be applied to the leather layer to adjust a hardness of the leather layer above filling member  1806 . A skiving method (discussed below) could also be used to remove a portion of outer layer  1404 . 
       FIG. 18C  shows a cross sectional side view of a sidewall or rear cover  1600  that includes an aperture  1612   f  for coupling a data cable to data port  1808  of electronic device  1800  disposed within an accessory unit. Depending on the electronic device, aperture  1612   f  could receive other members known in the art for coupling to an electronic device through an aperture of an accessory unit. Aperture  1612   f  can have sidewalls  1810  that extend normal from an outside surface of electronic device  1800 . When compared with an aperture cut in a direction substantially parallel to a top surface of electronic device  1800 , aperture  1612   f  avoids sharp angles jutting out and having a higher potential of fraying or even interfering with use of data port  1808 . Rather, aperture  1812   f , as shown in  FIG. 18C , is cut such that the circular wall is normal to the surface of electronic device  1800 . This design leaves edges of aperture  1612   f  less vulnerable to contact from external objects. While such an opening would normally require a three dimensional cutting path to be traced, a tapered cutter can be utilized to cut aperture  1612   f  as depicted without complexities associated with a three dimensional cutting path.  FIG. 18D  shows another configuration of aperture  1612   f  In this embodiment, a debossed aperture  1612   f  is depicted. Here, shell  1418  is made thinner near aperture  1612   f  to provide an appearance of an accessory unit having a narrower width. In some embodiments, shell  1418  can end prior to aperture  1612   f  such that only inner layer and outer layers remain at the edge of aperture  1612   f  In other embodiments, inner layer  1402  can made thinner and/or end prior to aperture  1612   f.    
     It should be understood that the depicted techniques can be applied to any of apertures  312  as depicted in  FIG. 1A . In contrast, apertures  312   e  (configured to audio from an electronic device to pass through accessory unit  100 ) can be formed using a different process. In one embodiment, apertures  312   e  can be drilled by a spindle head rotating at 80,000 rpm to create a substantially clean hole through rear cover  300 . In other embodiments, a spiral shaped cutter can be used to form apertures  312   e . The spiral shaped cutter can push chips towards a center portion of apertures  312   e , thereby forming a clean cut. 
       FIGS. 19A-19E  shows a series of illustrations describing a skiving method. Skiving can be applied by a skiving machine, to change characteristics of a fabric layer, and more specifically to change a material thickness of the fabric. A leather portion of front flap  200  may be too rigid along folding regions  204  (shown in  FIGS. 1A-2A ) for certain applications. This excessive rigidness may prohibit front flap  200  from easily folding to form a support structure. The skiving method offers a reliable method for removing material from front flap  200  to create, for example, folding regions  204 . 
       FIG. 19A  shows a template  1902  configured to establish a skiving pattern. In some embodiments template  1902  can be made of plastic and can includes protrusions  1904 ,  1906  that determine where material is to be removed. Although protrusions  1904 ,  1906  are depicted as being substantially the same size and shape, other sizes and shapes are possible and can serve different purposes. In other embodiments, there could be at least three protrusions. In  FIG. 19B , leather layer  1908  is laid across template  1902 , with the cosmetic side  1909  contacting template  1902 . By laying the cosmetic side  1909  against template  1902 , subsequent cutting operations do not substantially affect an exterior finish of leather layer  1908 . In  FIG. 19C  a cutting operation is performed along cutting line  1910 . The cutting operation can be performed by a thin slicing blade that cuts parallel to a top surface of template  1902 .  FIG. 19D  shows leather layer  1908  after the cutting operation. Because protrusions  1904 ,  1906  cause leather layer to curve gradually, a resulting thickness of leather layer  1908  also varies gradually (corresponding to protrusions  1904 ,  1906 ) to provide a smooth thickness transition. Finally,  FIG. 19E  shows leather layer  1908  removed from template  1902 . It should be noted that in addition to increasing flexibility in folding regions  204 , this skiving method can be used to provide space to embed various items beneath leather layer  1908 . For example, flexible circuits, wiring, and even magnetic elements could be partially or completely hidden by such a technique. 
       FIG. 20  shows a block diagram illustrating a method for assembling an accessory unit. In a first step  2002 , a shell and front flap segment inserts are provided. In one embodiment the shell can be a thin walled thermoformed plastic shell and the segment inserts can be glass fiber. In other embodiments, the shell can be formed by compression molding, or a combination of thermoforming and compression molding. In step  2004 , the shell and front flap segment inserts can be positioned between an outer layer and an inner layer. Segment inserts may include magnetic elements, filling elements (such as a plastic piece or silicone), or a combination thereof. In some embodiments, magnetic elements are formed inside the segments inserts, and accordingly, are disposed between the inner layer and the outer layer in conjunction with the segment inserts. 
     In step  2006 , the outer layer and inner layer are adhesively coupled together around both the shell and the front flap segments. In some embodiments, a complex press can be utilized that seals the outer layer and inner layer around the shell and front flap in a single bonding (or laminating) operation. In other embodiments, the microfiber layer is first adhesively bonded to an inside surface of the shell. The adhesive bond can be established by a thermoplastic or thermosetting adhesive. One advantage of a thermosetting adhesive is that lower setting temperatures can be used and an applicator can be utilized to spread the adhesive at varying thicknesses thereby generating regions of greater and lesser rigidity. In addition, the leather layer is not subject to higher heat that is required to activate other adhesives. 
     Subsequent to bonding the microfiber layer to a bottom portion of the shell, a spreading element can be utilized to adhere peripheral portions to sidewalls of the shell, including a top side of a lip portion of the shell as well as the sidewalls of the shell. After the microfiber is pressed against the shell the shell, the shell can be cooled to cause the adhesive to properly set. Cooling means may include running coolant through the tool (spreading element), cooling the tool (which extracts heat from the microfiber/shell configuration), using air jets in the tool to push air onto the microfiber/shell configuration, switching out the heated tool with a cool tool, or a combination thereof. Next, the leather layer is adhered to an opposite side of the shell. Subsequently, the leather layer and microfiber seal around the front flap segment inserts and various other internal components of the accessory unit. In step  2008 , a machining operation can be applied to form apertures and embossments along a surface of the accessory unit to provide easy access to controls on a compatible consumer electronic product. 
       FIGS. 21A-21D  show various alternative hybrid shell embodiments. The hybrid shell embodiments each include a shell formed by compression molding at least two different materials together. In this way different characteristics can be provided to different portions of the shell. Each of the following embodiments can be formed during a single compression molding operation. In  FIG. 21A  shell  2100  is made from substantially stiff material such as glass fiber or a carbon fiber weave. Portions  2102  and  2104  can correspond to an input/output openings that can be areas of high strain. In this way the potential strain on the cover can be ameliorated. In  FIG. 21B  shell  2110  is made from substantially flexible material, such as a thermoplastic. Regions  2112  and  2114  can correspond to edge areas to firm up a feel of the edge portions of the accessory unit. In some embodiments this can prevent the accessory unit from having a floppy edge feel. In other words, the accessory unit feels rigid and robust when held by a user. In  FIG. 21C , shell  2120  is made from a substantially flexible material and having an embedded attraction plate  2122  made from a magnetically attractable material such as steel. By embedding attraction the plate  2122  within shell  2120 , magnetic elements within the front flap can attract to the attraction plate  2122 , such that the front flap is secured to the shell  2120  during, for example, use of an electronic device.  FIG. 21D  shows a shell  2130  having a stiff outer periphery  2132  that can be formed from, for example, glass fiber. Outer periphery  2132  can include both a lip portion of shell  830  and at least sidewalls of shell  830 , such that a protected electronic device is firmly seated within the accessory unit. The shells described in  FIGS. 21A-D  may include an outer layer (such as leather) disposed on an outer surface of the shell. It should be understood that the outer layer is sufficiently thin and/or the magnetic attraction is sufficiently strong such that front flap attracts to shell. 
     Indicia, such as a logo or symbol, may be disposed on the front flap and/or the rear cover. Indicia can be formed by removing a portion of a surface of the leather layer corresponding to a shape of the logo. Unfortunately, the consistency or uniformity of an underlying layer of leather can vary in accordance with a grain or other individual characteristic of the leather. To compensation, in some embodiments, the underlying layer can be treated with water or steam to provide a particular color for the indicia. Variations in temperature, time and/or operating pressure can affect the color or colors obtained. To further create indicia with a more uniform appearance, a dye or ink can be applied to the indicia. 
       FIG. 22  is a block diagram of an arrangement  2200  of functional modules utilized by an electronic device. The electronic device can, for example, be a tablet computer. The arrangement  2200  includes an electronic device  2202  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  2204 . The arrangement  2200  also includes a graphical user interface (GUI) manager  2206 . The GUI manager  2206  operates to control information being provided to and displayed on a display device. The arrangement  2200  also includes a communication module  2208  that facilitates communication between the portable media device and an accessory device. Still further, the arrangement  2200  includes an accessory manager  2210  that operates to authenticate and acquire data from an accessory device that can be coupled to the portable media device. 
       FIG. 23  is a block diagram of an electronic device  2350  suitable for use with the described embodiments. The electronic device  2350  illustrates circuitry of a representative computing device. The electronic device  2350  includes a processor  2352  that pertains to a microprocessor or controller for controlling the overall operation of the electronic device  2350 . The electronic device  2350  stores media data pertaining to media items in a file system  2354  and a cache  2356 . The file system  2354  is, typically, a storage disk or a plurality of disks. The file system  2354  typically provides high capacity storage capability for the electronic device  2350 . However, since the access time to the file system  2354  is relatively slow, the electronic device  2350  can also include a cache  2356 . The cache  2356  is, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to the cache  2356  is substantially shorter than for the file system  2354 . However, the cache  2356  does not have the large storage capacity of the file system  2354 . Further, the file system  2354 , when active, consumes more power than does the cache  2356 . The power consumption is often a concern when the electronic device  2350  is a portable media device that is powered by a battery  2374 . The electronic device  2350  can also include a RAM  2370  and a Read-Only Memory (ROM)  2372 . The ROM  2372  can store programs, utilities or processes to be executed in a non-volatile manner. The RAM  2370  provides volatile data storage, such as for the cache  2356 . 
     The electronic device  2350  also includes a user input device  2358  that allows a user of the electronic device  1350  to interact with the electronic device  2350 . For example, the user input device  1558  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  2350  includes a display  2360  (screen display) that can be controlled by the processor  2352  to display information to the user. A data bus  2366  can facilitate data transfer between at least the file system  2354 , the cache  2356 , the processor  2352 , and the CODEC  2363 . 
     In one embodiment, the electronic device  2350  serves to store a plurality of media items (e.g., songs, podcasts, etc.) in the file system  2354 . 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  1560 . Then, using the user input device  2358 , a user can select one of the available media items. The processor  2352 , 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)  2363 . The CODEC  1563  then produces analog output signals for a speaker  2364 . The speaker  2364  can be a speaker internal to the electronic device  2350  or external to the electronic device  2350 . For example, headphones or earphones that connect to the electronic device  2350  would be considered an external speaker. 
     The electronic device  2350  also includes a network/bus interface  2361  that couples to a data link  2362 . The data link  2362  allows the electronic device  2350  to couple to a host computer or to accessory devices. The data link  2362  can be provided over a wired connection or a wireless connection. In the case of a wireless connection, the network/bus interface  2361  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  2376  can take the form of circuitry for detecting any number of stimuli. For example, sensor  2376  can include a Hall Effect sensor responsive to external magnetic field, an audio sensor, a light sensor such as a photometer, and so on. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20160725
Publication Date: 20180828
Grant Date: 20180828
Priority Date: 20130904
Inventors: SMITH, Samuel Gilkison
BALAJI, SANTHANA KRISHNAN
SARTEE, JARED A.
QIAN, AMY
MOOLSINTONG, PINIDA J.
Assignee: APPLE INC
CPC Classifications: [{"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B38/0036", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "B32B37/1284", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2305/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/182", "inventive": true, "first": false, "tree": "[]"}, {"code": "G05G1/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2305/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0086", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B38/0004", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B38/0008", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2398/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2375/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2375/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/182", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0226", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C11/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "G05G1/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B38/0008", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2305/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B1/3888", "inventive": true, "first": true, "tree": "[]"}, {"code": "B32B2305/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2398/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B38/0004", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/1284", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3888", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B38/0036", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C2011/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2398/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2305/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/182", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2305/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B38/0036", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0239", "inventive": true, "first": false, "tree": "[]"}, {"code": "G05G1/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B38/0008", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C2011/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B1/3888", "inventive": true, "first": true, "tree": "[]"}, {"code": "B32B38/0004", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0226", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2375/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B37/1284", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0086", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C11/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C11/002", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/002", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 52628859