PATENT DOCUMENT

Publication Number: US-11567542-B2
Application Number: US-202016821875-A
Country: US
Kind Code: B2

Title: Hinges for electronic devices and accessory devices

Abstract:
An accessory device for an electronic device is disclosed. The accessory device includes multiple sections, with one section holding the electronic device, and another section having an input mechanism, such as a keyboard. The accessory device includes a hinge assembly that allows relative movement of the sections with respect each other. An additional hinge assembly is integrated with the section carrying the electronic device, and provides additional flexibility and range of motion of the section, thereby allowing a user to position the electronic device at multiple different angles relative to the section carrying the input mechanism. Also, each hinge assembly may include multiple roller and spacer elements, as well as a retention structure passing through each roller element and spacer element. The retention structure can provide tension to increase the frictional force between the roller and spacer elements, and/or provide counterbalance to offset the weight of the electronic device.

Claims:
What is claimed is: 
     
       1. An accessory device suitable for use with an electronic device, the accessory device comprising:
 a first section comprising a first segment and a second segment; 
 a second section comprising an input mechanism configured to provide a command to the electronic device; 
 a first hinge assembly coupled to the first section and the second section, the first hinge assembly comprising:
 a first cylindrical roller element; 
 a second cylindrical roller element, wherein each of the first cylindrical roller element and the second cylindrical roller element comprises circular cross section; and 
 a spacer element having i) a first receiving surface engaging the first cylindrical roller element and ii) a second receiving surface engaging the second cylindrical roller element; and 
 
 a second hinge assembly coupled to the first segment and the second segment; and 
 a retention structure coupled to the first section and the second section, the retention structure passing through at least the first hinge assembly, 
 wherein a first position comprises the first section positioned over the second section and the first segment being fixed relative to the second segment, and 
 wherein a second position comprises the first section rotated away from the second section via the first hinge assembly such that the input mechanism is uncovered by the first section, and the first segment is rotated relative to the second segment via the second hinge assembly. 
 
     
     
       2. The accessory device of  claim 1 , wherein the first segment and the second segment define a receiving surface for the electronic device in the first position, and in the second position, a rotation of the first segment relative to the second segment causes the second segment to disengage from the electronic device. 
     
     
       3. The accessory device of  claim 2 , wherein the first hinge assembly allows the first segment to move relative to the second segment only in the second position. 
     
     
       4. The accessory device of  claim 1 , wherein the second position comprises the first section rotated away from the second section by a maximum angle of rotation between the first section and the second section, the maximum angle of rotation based upon the second hinge assembly. 
     
     
       5. The accessory device of  claim 1 ,
 wherein the first cylindrical roller element and the second cylindrical roller element rotate along the first receiving surface and the second receiving surface, respectively,
 while transitioning from the first position to the second position. 
 
 
     
     
       6. The accessory device of  claim 5 , wherein the spacer element comprises:
 a first insert having a first set of protrusions positioned in the first cylindrical roller element, the first set of protrusions directed toward a first portion of the spacer element; and 
 a second insert having a second set of protrusions positioned in the second cylindrical roller element, the second set of protrusions directed toward a second portion of the spacer element, the second portion being different from the first portion. 
 
     
     
       7. The accessory device of  claim 1 , further comprising:
 a tension adjustment system coupled to the retention structure, the tension adjustment system configured to adjust tension to the retention structure in the first position. 
 
     
     
       8. An accessory device suitable for use with an electronic device, the accessory device comprising:
 a first section that defines a receiving surface for the electronic device; 
 a second section comprising an input mechanism configured to provide a command to the electronic device; and 
 a hinge assembly coupled to the first section and the second section, the hinge assembly comprises:
 a first roller element that includes a first opening; 
 a second roller element that includes a second opening; and 
 a spacer element that engages the first roller element and the second roller element, the spacer element having i) a first protrusion located in the first opening and ii) a second protrusion located in the second opening, wherein
 the first roller element and the second roller element rotate along the spacer element while the first section rotates relative to the second section. 
 
 
 
     
     
       9. The accessory device of  claim 8 , further comprising a retention structure coupled to the first section and the second section, the retention structure that passes through the first roller element, the second roller element, and the spacer element. 
     
     
       10. The accessory device of  claim 9 , further comprising a shim structure positioned on the retention structure, the shim structure remains engaged with the first roller element and the second roller element. 
     
     
       11. The accessory device of  claim 8 , wherein the hinge assembly comprises a first hinge assembly, and wherein the first section comprises:
 a first segment; 
 a second segment; and 
 a second hinge assembly that couples the first segment with the second segment. 
 
     
     
       12. The accessory device of  claim 11 , wherein a first position comprises the first section positioned over the second section and the first segment being fixed relative to the second segment, and wherein a second position comprises the first section rotated away from the second section via the first hinge assembly, and the first segment is capable of rotation relative to the second segment via the second hinge assembly. 
     
     
       13. The accessory device of  claim 8 , wherein the spacer element comprises:
 a first convex surface that engages the first roller element; and 
 a second convex surface that engages the second roller element. 
 
     
     
       14. The accessory device of  claim 8 , further comprising a fastening component, wherein:
 the first roller element comprises a first roller element opening, 
 the second roller element comprises a second roller element opening, 
 the spacer element comprises a spacer element opening, and 
 the fastening component passes through the spacer element opening and is positioned in the first roller element opening and the second roller element opening. 
 
     
     
       15. An accessory device suitable for use with an electronic device, the accessory device comprising:
 a first section comprising a first segment and a second segment; 
 a second section comprising an input mechanism configured to provide a command to the electronic device, 
 a first hinge assembly coupled to the first section and the second section, the first hinge assembly comprising:
 a roller element having a first opening defined by a planar surface and a curved surface opposite the planar surface, 
 a spacer element engaging the roller element, the spacer element having a second opening, and 
 a retention structure passing through the first opening and the second opening, the retention structure secured to the first section and the second section; and 
 
 a second hinge assembly that rotationally couples the first segment with the second segment 
 wherein a first position comprises:
 the first segment and the second segment engaging the electronic device, and 
 the retention structure engaging the planar surface, and 
 
 wherein a second position comprises:
 the first section rotated relative to the second section to a maximum angle based on the second hinge assembly, 
 the retention structure engaging the curved surface, and 
 the second segment is free of contact with the electronic device. 
 
 
     
     
       16. The accessory device of  claim 15 , wherein the maximum angle is between 50 and 75 degrees. 
     
     
       17. The accessory device of  claim 15 , wherein:
 the first segment comprises a first magnet configured to form a first magnetic coupling with a first device magnet of the electronic device, 
 the second segment comprising a second magnet configured to form a second magnetic coupling with a second device magnet of the electronic device, and 
 rotation of the first segment relative to the second segment overcomes the second magnetic coupling. 
 
     
     
       18. The accessory device of  claim 15 , wherein the planar surface is defined by a flat surface and the curved surface is defined by a convex surface. 
     
     
       19. The accessory device of  claim 15 , wherein the first hinge assembly provides a counterbalance force that offsets the electronic device, and wherein the counterbalance force varies based upon a relative position between the first segment and the second segment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of priority to i) U.S. Provisional Application No. 62/820,199, filed on Mar. 18, 2019, titled “HINGES FOR ELECTRONIC DEVICES AND ACCESSORY DEVICES,” and ii) U.S. Provisional Application No. 62/895,394, filed on Sep. 3, 2019, titled “HINGES FOR ELECTRONIC DEVICES AND ACCESSORY DEVICES,” the disclosure of EACH is incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The following description relates to hinges that are integrated with electronic devices and accessory devices. In particular, the following description relates to hinges formed from an assembly of multiple roller elements, as well as multiple spacer elements, or linking elements, positioned between adjacent roller elements. In order to maintain engagement between the roller elements and spacer elements, a hinge described herein may include one or more retention structures, or straps, that pass through each roller element and each spacer element. In order for the hinge to rotate or re-position sections or housing parts of the accessory devices and electronic devices, the hinge allows for rotational movement of the roller elements relative to the spacer elements, along with synchronous movement of the roller elements and the spacer elements. 
     BACKGROUND 
     Portable electronic devices and accessory devices may include a hinge that allows rotational movement of one part relative to another part. Some hinges include a C-shaped friction clip that surrounds a shaft. While one part (of the portable electronic device or accessory device) is rotated relative to the other part, the friction clip rotates around the shaft. When the rotation ceases, the friction between the friction clip and the shaft hold the parts in a fixed position. 
     These types of hinges have some drawbacks. For instance, the holding force (due to frictional engagement between the C-shaped friction clip and the shaft) is a function of the size of the friction clip and the shaft. Accordingly, the size must be adjusted based upon the weight of the device. Further, in the instance of an accessory device, the size must be adjusted based upon the weight of not only some parts of the accessory device, but also the weight of an electronic device that is carried by the accessory device. 
     SUMMARY 
     In one aspect, an accessory device suitable for use with an electronic device is described. The accessory device may include a first section that includes a first segment and a second segment coupled to the first segment by a first hinge assembly. The accessory device may further include a second section coupled to the first section by a second hinge assembly. The second section may include an input mechanism configured to provide a command to the electronic device. In some instances, a first position comprises the first section positioned over the second section and the first segment being fixed relative to the second segment. Also, in some instances, a second position includes the first section rotated away from the second section via the first hinge assembly such that the input mechanism is uncovered by the first section, and the first segment is rotated relative to the second segment via the second hinge assembly. 
     In another aspect, an accessory device suitable for use with an electronic device is described. The accessory device may include a first section that defines a receiving surface for the electronic device. The accessory device may further include a second section that includes an input mechanism configured to provide a command to the electronic device. The accessory device may further include a hinge assembly coupled to the first section and the second section. The hinge assembly may include a first roller element. The hinge assembly may further include a second roller element. The hinge assembly may further include a spacer element that engages the first roller element and the second roller element. In some instances, the first roller element and the second roller element rotate along the spacer element while the first section rotates relative to the second section. 
     In another aspect, an accessory device suitable for use with an electronic device is described. The accessory device may include a first section that includes a first segment and a second segment coupled to the first section by a first hinge assembly. The accessory device may further include a second section coupled to the first section by a second hinge assembly. The second section may include an input mechanism configured to provide a command to the electronic device. In some instances, a first position includes the electronic device engaged with the first segment and the second segment. Also, in some instances, a second position includes the first section rotated relative to the second section to a maximum angle based on the second hinge assembly, and the second segment is free of contact with the electronic device. 
     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.  1    illustrates an isometric view of an embodiment of an accessory device, showing the accessory device in an open position, in accordance with some described embodiments; 
         FIG.  2    illustrates an isometric view of the accessory device shown in  FIG.  1   , showing the accessory device in a closed position; 
         FIG.  3    illustrates an isometric view of the accessory device holding an electronic device; 
         FIG.  4    illustrates a side view of the accessory device and the electronic device, showing the accessory device in an open position, in accordance with some described embodiments; 
         FIG.  5    illustrates a side view of the accessory device and the electronic device, showing the accessory device in a closed position, in accordance with some described embodiments; 
         FIG.  6    illustrates a side view of the accessory device and the electronic device, showing the accessory device in an open position in which the section that carries the electronic device is rotated away from the section that includes the input mechanism, in accordance with some described embodiments; 
         FIG.  7    illustrates a side view of the accessory device and the electronic device, showing the accessory device in an open position, with the section carrying the electronic device further rotated by the hinge assembly; 
         FIG.  8    illustrates a side view of the accessory device, showing the accessory device carrying the device at an angle; 
         FIG.  9    illustrates a side view of the accessory device carrying the electronic device at an alternate angle; 
         FIG.  10    illustrates a side view of the accessory device, showing the accessory device in a closed positioned and carrying the electronic device; 
         FIG.  11    illustrates an exploded view of components of a hinge assembly, in accordance with some described embodiments; 
         FIG.  12    illustrates a cross sectional view of an embodiment of an accessory device, showing a hinge assembly and a retention structure passing through the hinge assembly, in accordance with some described embodiments; 
         FIG.  13    illustrates a cross sectional view of the accessory device shown in  FIG.  12   , showing the hinge assembly and components the hinge assembly interlocked with each other; 
         FIG.  14    illustrates an isometric view of an alternate embodiment of a spacer element, showing the spacer element with inserts that include protrusions that extend in different directions, in accordance with some described embodiments; 
         FIG.  15    illustrates an isometric view of the spacer element shown in  FIG.  14   , showing the inserts prior to installing in the spacer element; 
         FIG.  16    illustrates a cross sectional view of the spacer element shown in  FIG.  14   , taken along line  16 - 16 , showing the insert positioned in the spacer element; 
         FIG.  17    illustrates a cross sectional view of the spacer element shown in  FIG.  14   , taken along line  17 - 17 , showing the insert positioned in the spacer element; 
         FIG.  18    illustrates a cross sectional view of a hinge assembly, in accordance with some described embodiments; 
         FIG.  19    illustrates a side view of an accessory device with the hinge assembly shown in  FIG.  18    integrated with the accessory device; 
         FIG.  20    illustrates a cross sectional view of the hinge assembly shown in  FIG.  18   , showing the spacer elements with additional inserts, in accordance with some described embodiments; 
         FIG.  21    illustrates a side view of the accessory device shown in  FIG.  19   , showing the accessory device further limited in movement based on the hinge assembly; 
         FIG.  22    illustrates a cross sectional view of an embodiment of a roller element for use with a hinge assembly, in accordance with some described embodiments; 
         FIG.  23    illustrates a cross sectional view of an embodiment of an accessory device, showing a hinge assembly and a retention structure passing through the hinge assembly, in accordance with some described embodiments; 
         FIG.  24    illustrates an isometric view of an embodiment of a retention structure with a shim structure, in accordance with some described embodiments; 
         FIG.  25    illustrates a cross sectional view of an embodiment of an accessory device with a hinge assembly, showing the retention structure and the shim structure shown in  FIG.  24    integrated with the hinge assembly, in accordance with some described embodiments; 
         FIG.  26    illustrates a cross sectional view of the accessory device shown in  FIG.  25   , showing the hinge assembly positioning the accessory device at a different angle; 
         FIG.  27    illustrates a cross sectional view of an alternate embodiment of an accessory device and a hinge assembly, showing the hinge assembly positioning the accessory device at an angle greater than 180 degrees, in accordance with some described embodiments; 
         FIG.  28    illustrates a cross sectional view of an alternate embodiment of a roller element for use with a hinge assembly, in accordance with some described embodiments; 
         FIG.  29    illustrates a cross sectional view of an alternate embodiment of an accessory device, showing a hinge assembly and a retention structure passing through the hinge assembly, in accordance with some described embodiments; 
         FIG.  30    illustrates a side view of an alternate embodiment of an accessory device, showing a retention structure passing through multiple hinge assemblies, in accordance with some described embodiments. 
         FIG.  31    illustrates a side view of an alternate embodiment of an accessory device, showing multiple hinge assemblies, each with a retention structure, in accordance with some described embodiments; 
         FIG.  32    illustrates an exploded view of an alternate embodiment of a hinge assembly, showing the various components of the hinge assembly; 
         FIG.  33 A  illustrates a cross sectional view of the hinge assembly shown in  FIG.  32   , showing the elements of the hinge assembly secured together; 
         FIG.  33 B  illustrates a cross sectional view of the hinge assembly shown in  FIG.  33 A , showing relative movement of some of the elements of the hinge assembly; 
         FIG.  34    illustrates an isometric view of a roller element of the hinge assembly shown in  FIGS.  32 - 33 B , showing exemplary movement of the fastening component; 
         FIG.  35 A  illustrates a cross sectional view of an alternate embodiment of a hinge assembly; 
         FIG.  35 B  illustrates a cross sectional view of the hinge assembly shown in  FIG.  35 A , showing relative movement of some of the elements of the hinge assembly; 
         FIG.  36    illustrates a cross sectional view of an alternate embodiment of a hinge assembly, showing the hinge assembly with multiple flexible components; 
         FIG.  37    illustrates a cross sectional view of the hinge assembly shown in  FIG.  36   , showing relative movement of some of the elements of the hinge assembly; 
         FIG.  38    illustrates an isometric view of an embodiment of a retention structure, showing several layers of materials secured with the ends of the retention structure; 
         FIG.  39    illustrates an isometric view of an alternate embodiment of a hinge assembly, showing several cables passing through a roller element of the hinge assembly; 
         FIG.  40    illustrates a cross sectional view of a hinge assembly, showing a cable passing through several components of the hinge assembly; 
         FIG.  41    illustrates a plan view of an alternate embodiment of a hinge assembly, showing several cables of the hinge assembly, with each cable connected to a flexible component; 
         FIG.  42    illustrates a plan view of an alternate embodiment of a hinge assembly, showing several cables of the hinge assembly, and further showing a flexible component coupled with the cables; 
         FIG.  43    illustrates a plan view of an alternate embodiment of a hinge assembly, showing a roller element and a single cable passing through several openings of the roller element; 
         FIG.  44    illustrates an isometric view of an embodiment of a roller element, showing several grooves on an outer circumference of the roller element; 
         FIG.  45    illustrates an isometric view of an embodiment of a roller element with a coating on an outer circumference of the roller element, further showing a textured pattern applied to the coating; 
         FIG.  46    illustrates a cross sectional view of an embodiment of a roller element, showing the roller element defined by multiple materials; 
         FIG.  47    illustrates a cross sectional view of an embodiment of a roller element, showing the roller element defined by multiple materials; 
         FIG.  48    illustrates an isometric view of an embodiment of an accessory device with retention structures, showing each retention structure coupled to a tension adjustment system, in accordance with some described embodiments; 
         FIG.  49    illustrates a plan view of an embodiment of a tension adjustment system, in accordance with some described embodiments; 
         FIG.  50    illustrates a plan view of the extension and the coupling mechanism shown in  FIG.  49    of the tension adjustment system, showing several features of the extension and the coupling mechanism; 
         FIG.  51    illustrates a side view of the accessory device in an open position, in accordance with some described embodiments; 
         FIG.  52    illustrates a plan view of the tension adjustment system, showing the position of the extension relative to the coupling mechanism when the accessory device is in the open position shown in  FIG.  51   ; 
         FIG.  53    illustrates a side view of the accessory device in a closed position, subsequent to a transition from the open position, in accordance with some described embodiments; 
         FIG.  54    illustrates a plan view of the tensioning adjustment system, showing the position of the extension relative to the coupling mechanism when the accessory device is in the closed position shown in  FIG.  53   ; 
         FIG.  55    illustrates an isometric view of an alternate embodiment of an accessory device, showing an alternate arrangement of retention structures passing through multiple hinge assemblies, in accordance with some described embodiments; 
         FIG.  56    illustrates an isometric view of an alternate embodiment of an accessory device, showing a different number of retention structures passing through hinge assemblies, in accordance with some described embodiments; 
         FIG.  57    illustrates a side view of an alternate embodiment of an accessory device with an automated opening system, showing the accessory device in a closed position, in accordance with some described embodiments; 
         FIG.  58    illustrates a side view of the accessory device shown in  FIG.  47   , showing the accessory device in an open position using the automated opening system; 
         FIG.  59    illustrates an isometric view of an embodiment of a portable electronic device, showing the accessory device in an open position, in accordance with some described embodiments; 
         FIG.  60    illustrates a side view of the portable electronic device shown in  FIG.  59   , showing the portable electronic device in a closed position; 
         FIG.  61    illustrates an isometric view of an alternate embodiment of a portable electronic device, showing the portable electronic device in an open position, in accordance with some described embodiments; 
         FIG.  62    illustrates a side view of the portable electronic device shown in  FIG.  61   , showing the portable electronic device in a closed position; and 
         FIG.  63    illustrates a block diagram of an electronic device, in accordance with some 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. 
     The following disclosure relates to an accessory device that is suitable for use with portable electronic devices, including mobile wireless communication devices (such as smartphones and tablet computer devices). Accessory devices described herein may include multiple sections, or covers, that are coupled to each other by a hinge assembly, thereby allowing the sections to move relative to each other (based upon the hinge assembly). For instance, one section is designed to receive and couple with the portable electronic device by, for example, magnets, while another section may include an input mechanism (such as a keyboard, a display, a touch pad, or a combination thereof). Using the hinge assembly, the section that holds the portable electronic device can fold away from the section that includes the input mechanism. Further, when the portable electronic device is no longer in use, the hinge assembly allows the sections to move and surround the portable electronic device, which increases eases of portability and protection of the portable electronic device. 
     The accessory device may include an additional hinge assembly that increases the overall performance of the accessory device. For example, the additional hinge assembly may be integrated into the section carrying the portable electronic device, thereby partitioning the section into two segments. In this manner, when the accessory device is in an open position, the additional hinge assembly allows relative movement between the segments. As a result, the section carrying the portable electronic device provides a range of motion, and the portable electronic device can be rotated to different positions. This allows the user to adjust the portable electronic device relative to the input mechanism such that the user can position the portable electronic device in a desired manner. 
     The hinge assemblies described herein may include one or more roller elements (including cylindrical bodies) engaged with spacer elements (or linking elements), with a spacer element positioned between adjacent roller elements. Each spacer element can provide multiple surfaces, each of which is contoured to the shape of a roller element. The movement of the hinge assembly is based in part upon the roller elements rotating along the spacer elements, as well as movement of the roller elements and the spacer elements in multiple dimensions (that is, in a three-dimensional space). Further, in some instances, the roller elements and the spacer elements synchronously move together to provide a more fluid movement of the hinge assembly, as well as the sections (of the accessory device) coupled together by the hinge assembly. 
     In order to maintain engagement between the roller elements and the spacer elements, hinge assemblies described herein may include one or more retention structures, or straps, that pass through each roller element and each spacer element. The retention structures may include flexible properties, but may also provide stiffness to maintain the hinge assembly (as well as a section, or sections, coupled to the hinge assembly) in a fixed position. In some instances, the tension provided by the retention structures can be adjusted, which can cause an adjustment to the frictional forces between the roller elements and the spacer elements. As a result, the frictional engagement may be based upon the retention structure under tension. Further, due in part to this friction engagement providing a holding force to support parts of the accessory device and an electronic device carried by the electronic device, the hinge assembly is less dependent upon the size of components (such as the roller elements and the spacer element), as compared to traditional hinges with C-shaped friction clips and shafts engaged with the friction clips. 
     While a retention structure may pass through the center of the hinge assembly, in some instances, a hinge assembly described herein includes components manufactured such that a retention structure is offset through the hinge assembly. In other words, the retention structure passes through some point other than the center of the hinge assembly. As a result, the retention structure, under tension, can provide a force to the hinge assembly, thereby promoting a transition of the accessory device to an open position or a closed position, depending upon the offset position of the retention structure. 
     In addition to the offset position of the retention structure, the motion of the hinge assembly can be a function of one or more variables. For example, the amount of tension, or pulling force, applied to the strap can affect the torque applied to the hinge assembly. Further, the thickness of the strap can affect the ability of the strap to bend, or resist bending. Also, in some instances, when the accessory device transitions from an open position to a closed position, the length of the strap changes. The strap may respond by resisting the length change, thereby increasing the frictional force between the components to the hinge assembly. The increased frictional force can increase the torque required to move the hinge assembly. Further, when the accessory device holds an electronic device, the counterforce, or holding force, provided by the accessory device depends upon the angle at which the hinge assembly positions the section(s) holding the electronic device. In this regard, the force provided by the hinge assembly changes based upon the position of the hinge assembly. Accordingly, the counterforce provided by the hinge assembly is a function of the angular position of the section(s). The aforementioned variables can all be manipulated to provide an accessory device with a desired user experience. 
     These and other embodiments are discussed below with reference to  FIGS.  1 - 63   . 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. 
       FIG.  1    illustrates an isometric view of an embodiment of an accessory device  100 , showing the accessory device  100  in an open position, in accordance with some described embodiments. The accessory device  100  is designed to hold/carry a portable electronic device (not shown in  FIG.  1   ), such as mobile wireless communication devices including smartphones and tablet computing devices. As shown, the accessory device  100  includes a section  102   a  and a section  102   b . The section  102   a  and the section  102   b  may be referred to as a first section and a second section, respectively. However, these designations of first and second sections can be interchangeable. 
     The section  102   a  may be divided into multiple segments. For example, as shown, the section  102   a  includes a segment  104   a  and a segment  104   b . The segment  104   a  and the segment  104   b  may be referred to as a first segment and a second segment, respectively. However, these designations of first and second segments can be interchangeable. The segment  104   a  and the segment  104   b  may provide a receiving surface for the portable electronic device. Further, the section  102   a  may hold and carry the portable electronic device using magnets. For example, the segment  104   a  includes a magnet  106   a , a magnet  106   b , a magnet  106   c , and a magnet  106   d . The segment  104   b  includes a magnet  106   e  and a magnet  106   f  These aforementioned magnets may magnetically couple with one or more magnets (not shown in  FIG.  1   ) in the portable electronic device such that the portable electronic device remains coupled/engaged to the segment  104   a  and the segment  104   b . Also, although specific locations of the magnets are shown, the magnets may be generally located in the segment  104   a  and the segment  104   b  at locations corresponding the locations of the magnets in the portable electronic device. 
     The section  102   b  may include an input mechanism  108  designed to provide a command or input to the portable electronic device. In some embodiments, the input mechanism  108  is a touch input display (or touchscreen) with user input capabilities by way of touching the touch input display. In the embodiment shown in  FIG.  1   , the input mechanism  108  is a keyboard. In order to place the input mechanism  108  in communication with the portable electronic device, the accessory device  100  may include contacts  112  located on the section  102   a . The contacts  112  may include metal contacts that engage metal contacts (not shown in  FIG.  1   ) of the portable electronic device, thereby placing the accessory device  100  (including the input mechanism  108 ) in communication with processing circuitry (not shown in  FIG.  1   ) of the portable electronic device. As shown, the contacts  112  are located on the segment  104   a . However, the contacts  112  may be located on the segment  104   b , depending on the location of the contacts on the portable electronic device. Also, it should be noted that the accessory device  100  may include wireless circuitry (not shown in  FIG.  1   ), such as Bluetooth® circuitry or near-field communication (“NFC”) circuitry, designed to provide wireless communication with the portable electronic device, thereby providing a wireless method for transferring communication from the input mechanism  108  to the portable electronic device. 
     The accessory device  100  is designed to provide different benefits based upon the orientation/position of the accessory device  100 . In this regard, the accessory device  100  includes hinges, or hinge assemblies, that allow relative movement between the sections and segments of the accessory device  100 . For example, the accessory device  100  may include a hinge assembly  114   a  coupled to the section  102   a  and the section  102   b . The hinge assembly  114   a  allows relative movement between the section  102   a  and the section  102   b . The accessory device  100  may further include a hinge assembly  114   b  coupled to the segment  104   a  and the segment  104   b . The hinge assembly  114   b  allows relative movement between segment  104   a  and the segment  104   b . Based upon the configurations permitted by the hinge assembly  114   a  and the hinge assembly  114   b , the accessory device  100  may transition to multiple different configurations, such as the open position shown in  FIG.  1    as well as several other configurations shown and described below. 
     Both the hinge assembly  114   a  and the hinge assembly  114   b  may include multiple roller elements and spacer elements (not labeled). In order to maintain engagement between the roller elements and the spacer elements, the hinge assembly  114   a  and the hinge assembly  114   b  may include retention structures passing through the roller elements and the spacer elements. As shown in  FIG.  1   , the hinge assembly  114   a  includes a retention structure  116   a , a retention structure  116   b , a retention structure  116   c  and a retention structure  116   d . Further, the hinge assembly  114   b  includes the retention structure  116   b  and the retention structure  116   c . Due in part to the retention structure  116   b  and the retention structure  116   c  passing through the hinge assembly  114   b , the movement of the hinge assembly  114   a  may dictate the movement of the hinge assembly  114   b , and vice versa. This will be further discussed below. 
     The retention structures may be referred to as straps. The retention structures described herein may include a material (or materials) such as a metal (including steel), glass fiber, and/or carbon fiber. Also, the material and the thickness of the retention structures are selected to allow the hinge assembly  114   a  and the hinge assembly  114   b  to bend in accordance with a desired bend radius as well as a desired stiffness. The thickness of the retention structures may be proportional to the stiffness, and inversely proportional to the bend radius. Accordingly, the thickness should be selected to achieve desired properties of the hinge assemblies. 
     Due in part to the retention structures maintaining engagement between the roller elements and the spacer elements of the hinge assemblies, the retention structures may dictate, or at least partially dictate, the frictional force between roller elements and spacer elements. In this regard, the retention structures can be affixed to an adjustment mechanism (not shown in  FIG.  1   ), including a spring-loaded adjustment mechanism (as a non-limiting example), located in the section  102   a  and/or the section  102   b . The adjustment mechanism(s) can adjust the tension on the retention structures, thereby providing an adjustment to frictional forces between the roller elements and the spacer elements. This may allow the accessory device  100  to remain in the open position, as shown in  FIG.  1   . 
       FIG.  2    illustrates an isometric view of the accessory device  100  shown in  FIG.  1   , showing the accessory device  100  in a closed position. In the closed position, based on movement allowed by the hinge assembly  114   a , the section  102   a  is positioned over, and substantially covers, the section  102   b . Further, in the closed position, the hinge assembly  114   b  may prevent relative movement between the segment  104   a  and the segment  104   b . In other words, the hinge assembly  114   b  is essentially locked, thereby keeping the segment  104   a  co-planar with the segment  104   b.    
       FIG.  3    illustrates an isometric view of the accessory device  100  holding an electronic device  180 . The electronic device  180  may include a portable electronic device, such as a mobile wireless communication device or a tablet computing device. The electronic device  180  includes a housing  181  designed to carry several components (such as a display, processing circuitry, memory circuitry, batteries, speakers, microphones, cameras, flexible circuitry, etc.) of the electronic device  180 . Further, the electronic device  180  includes several magnets carried by the housing  181 . The magnets of the accessory device  100  are designed to magnetically couple with the magnets of the electronic device  180 . For example, the electronic device  180  includes a magnet  182   a , a magnet  182   b , a magnet  182   c , and a magnet  182   d  that magnetically couples with the magnet  106   a , the magnet  106   b , the magnet  106   c , and the magnet  106   d , respectively. Further, the magnetic attraction force between the magnets of the electronic device  180  and the magnets of the accessory device  100  can hold and suspend the electronic device  180  over the section  102   b  such that the electronic device  180  is not in contact with the section  102   b , as shown in  FIG.  3   . 
     When the aforementioned magnets of the accessory device  100  magnetically couple to the aforementioned magnets of the accessory device  100 , the electronic device  180  is held against the accessory device  100 , and in particular, against the segment  104   a . Also, the electronic device  180  may further include a magnet  182   e  and a magnet  182   f . The magnet  106   e  and the magnet  106   f  of the accessory device  100  are designed and positioned to magnetically couple with the magnet  182   e  and the magnet  182   f , respectively, of the electronic device  180 . However, as shown in  FIG.  3   , the electronic device  180  is rotated away from the segment  104   b , based on movement allowed by the hinge assembly  114   b . As a result, the magnet  106   e  and the magnet  106   f  are not magnetically coupled with the magnet  182   e  and the magnet  182   f , respectively. However, it should be noted that when the electronic device  180  is engaged with the segment  104   b , the magnet  106   e  and the magnet  106   f  are magnetically coupled with the magnet  182   e  and the magnet  182   f , respectively. 
     The accessory device  100  provides a benefit to a user by holding the electronic device  180  upright (as shown in  FIG.  3   ). Further, based upon movement allowed the hinge assembly  114   a  and the hinge assembly  114   b , the accessory device  100  can position the electronic device  180 , including a display  184  (designed to present visual information) of the electronic device  180 , in a manner that the user can easily and readily use the input mechanism  108  of the accessory device  100  while viewing the display  184  of the electronic device  180 . 
       FIG.  4    illustrates a side view of the accessory device  100  and the electronic device  180 , showing the accessory device  100  in an open position, in accordance with some described embodiments. As shown, the accessory device  100  is generally flat in this open position and the electronic device  180  can lie flat on the segment  104   a  and the segment  104   b . It should be understood that additional “open positions” are possible, such as the position of the accessory device  100  shown in  FIG.  3   . Also, in some embodiments, the accessory device  100  includes a dimension  120  that defines a uniform thickness of the accessory device  100 . For example, the section  102   a  (including the segment  104   a  and the segment  104   b ), the hinge assembly  114   a , the hinge assembly  114   b , and the section  102   b  can each include a thickness equal to the dimension  120 . As a result, the accessory device  100  may provide a consistent finish in terms of size. Further, the accessory device  100  may provide an appearance, initially, of a single piece of material with portions removed for the hinge assemblies, based upon the uniform thickness defined by the dimension  120 . 
       FIG.  5    illustrates a side view of the accessory device  100  and the electronic device  180 , showing the accessory device  100  in a closed position, in accordance with some described embodiments. In the closed position, the accessory device  100  surrounds the electronic device  180 . For instance, the section  102   b  covers a front face that includes the display (not labeled) of the electronic device  180 , while the section  102   a  covers, or at least substantially covers, the housing  181 . In order to fold the accessory device  100 , the hinge assembly  114   a  allows the section  102   a  to move relative to the section  102   b , or vice versa. However, due to the position of the electronic device  180  relative to the section  102   b , the hinge assembly  114   b  is stationary, allowing no relative movement between the segment  104   a  and the segment  104   b . Also, as shown in  FIG.  5   , the hinge assembly  114   a  may be sufficiently stiff or rigid in this closed position to prevent contact between the electronic device  180  and the section  102   a , including the input mechanism  108 . 
     Further, in the closed position, at least some of the magnets located in section  102   a  magnetically couple with at least some of the magnets in the electronic device  180 , and the housing  181  of the electronic device  180  remains engaged with the section  102   b . For example, the magnet  106   a , the magnet  106   c , and the magnet  106   e  in the section  102   a  magnetically couple with the magnet  182   a , the magnet  182   c , and the magnet  182   e , respectively, in the electronic device  180 . Although not shown, additional magnetic couplings may occur. 
       FIGS.  6  and  7    illustrate an exemplary movement of the accessory device  100 , and in particular, an exemplary movement of the hinge assembly  114   a  and the hinge assembly  114   b .  FIG.  6    illustrates a side view of the accessory device  100  and the electronic device  180 , showing the accessory device  100  in an open position in which the section  102   a  that carries the electronic device  180  is rotated away from the section  102   b  that includes the input mechanism  108 , in accordance with some described embodiments. Using the hinge assembly  114   a , the section  102   a  is rotated away from the section  102   b  to an angle  130   a . In some embodiments, the angle  130   a  represents the greatest or maximum angle allowed by the hinge assembly  114   a . In other words, when the section  102   a  is positioned at the angle  130   a  relative to the section  102   b , the hinge assembly  114   a  does not allow additional rotational movement of the section  102   a  away from the section  102   b . The angle  130   a  may be approximately in the range of 50 to 80 degrees. In some embodiments, the angle  130   a  is between 55 and 70 degrees. Furthermore, during the rotation (permitted by the hinge assembly  114   a ) of the section  102   a  relative to the section  102   b , the hinge assembly  114   b  may remain stationary or fixed such that no relative movement between the segment  104   a  and the segment  104   b  occurs, and the section  102   b  remains substantially flat. Also, despite the relative movement of the section  102   a , the electronic device  180  can remain coupled to the section  102   a  by way of the aforementioned magnets. As shown, the magnet  106   a , the magnet  106   c , and the magnet  106   e  in the section  102   a  remain magnetically coupled with the magnet  182   a , the magnet  182   c , and the magnet  182   e , respectively, in the electronic device  180 . Additional magnetic coupling (not shown in  FIG.  6   ) may also occur. 
       FIG.  7    illustrates a side view of the accessory device  100  and the electronic device  180 , showing the accessory device  100  in an open position, with the section  102   a  carrying the electronic device  180  further rotated by the hinge assembly  114   b . As shown, when the section  102   a , and in particular the segment  104   b  of the section  102   a , is positioned at the angle  130   a  relative to the section  102   b , the hinge assembly  114   b  is permitted to move, thereby allowing the segment  104   a  to move or rotate relative to the segment  104   b . When the segment  104   a  is allowed to move relative to the segment  104   b , the accessory device  100  permits additional movement of the electronic device. As shown, when the segment  104   a  relative to the segment  104   b , the electronic device  180  is no longer coupled to the segment  104   b . The magnet  106   a  and the magnet  106   c  in the segment  104   a  remain magnetically coupled with the magnet  182   a  and the magnet  182   c , respectively, in the electronic device  180 . However, the magnet  106   e  in the segment  104   b  is no longer magnetically coupled with the magnet  182   f  in the electronic device  180 . Accordingly, despite the relative movement of the segment  104   a  relative to the segment  104   b , the electronic device  180  can remain at least partially coupled to the section  102   a  by way of the aforementioned magnetic couplings. 
     The hinge assembly  114   b  allows the segment  104   a  to rotate to an angle  130   b , representing an angle relative to an initial position (shown as dotted lines) of the segment  104   a . The angle  130   b  may represent the greatest or maximum angular movement of the segment  104   a  relative to the initial position, with the initial position corresponding to the position of the section  102   a  (particularly the segment  104   b ) when positioned relative to the section  102   b  at the angle  130   a . The angle  130   b  may be approximately in the range of 30 to 60 degrees. In some embodiments, the angle  130   b  is between 40 and 50 degrees. 
     As a result of the movement of the hinge assembly  114   a  and the hinge assembly  114   b , the electronic device  180  can be positioned an angle  130   c  relative to the section  102   b , and in particular, relative to the input mechanism  108 . The angle  130   c  may be approximately in the range of 90 to 150 degrees. In some embodiments, the angle  130   c  is between 120 and 140 degrees. 
     The dynamics of the hinge assemblies of the accessory device  100  provide certain advantages. For example, prior to the section  102   a  rotating (relative to the section  102   b ) to the angle  130   a  by way of the hinge assembly  114   a , the hinge assembly  114   b  may be prohibited from movement. However, when the section  102   a  rotates to the angle  130   a  by way of the hinge assembly  114   a , the hinge assembly  114   a  may become stationary (that is, prevented from further movement) such that the section  102   a  is not permitted to move toward or away from the section  102   b , while the hinge assembly  114   b  allows the segment  104   a  to move relative to the segment  104   b . Also, when the segment  104   a  is subsequently positioned at the initial position (shown as dotted lines), then hinge assembly  114   b  again becomes stationary (with no relative movement between the segment  104   a  and the segment  104   b ), and the hinge assembly  114   a  is allowed to move, such that the section  102   a  can move toward the section  102   b  to place the accessory device  100  in the closed position (shown in  FIG.  4   ). Accordingly, the accessory device  100  provides added stability by regulating movement of the hinge assembly  114   a  and the hinge assembly  114   b  based upon certain positions and configurations of the accessory device  100 . 
       FIGS.  8 - 10    show additional features of the hinge assemblies of the accessory device  100 . The hinge assemblies shown and described in  FIGS.  8 - 10   , as well as other hinge assemblies described herein, may provide a variable holding force that is a function of several factors such as the friction between the components of the hinge assemblies, the relative position of the retention structures within the hinge assemblies, the thickness of the retention structures, the stiffness of the retention structures, and the spring constant of the retention structures, as non-limiting examples. The holding force is related to the ability of the hinge assemblies to maintain/hold the accessory device with at a given position, either with or without carrying an electronic device. 
       FIG.  8    illustrates a side view of the accessory device  100 , showing the accessory device  100  carrying the electronic device  180  at an angle  130   d . The hinge assembly  114   a  and the hinge assembly  114   b  combine to hold the electronic device  180  at the angle  130   d  relative to the section  102   b . In particular, the hinge assembly  114   b  provides a counterforce that balances the weight of the electronic device  180  (and portions of the section  102   a ) and resists unwanted movement of the section  102   a . The counterforce provided by the hinge assembly  114   b  may be a function of the retention structure  116   b , including the properties of the retention structure  116   b  (and other retention structures of the hinge assembly  114   b  shown in  FIG.  1   ). For instance, the stiffness and thickness of the retention structure  116   b , the angle at which the segments connected to the hinge assembly  114   b  are positioned, the spring constant of the retention structure  116   b , pre-bending (if applicable) of the retention structure  116   b , and the relative position of the retention structure  116   b  within the hinge assembly  114   b  (discussed below) affect the ability of the hinge assembly  114   b  to provide a counterbalance to support the electronic device  180 . 
     Additional movement of the accessory device  100  may change the counterforce properties of the hinge assembly  114   b . For example,  FIG.  9    illustrates a side view of the accessory device  100  carrying the electronic device  180  at an angle  130   e  different from the angle  130   d  (shown in  FIG.  8   ). As shown, the segment  104   a  rotates (using the hinge assembly  114   b ) relative to the segment  104   b , thereby rotating the electronic device  180  and providing a user with a different viewing angle of the electronic device  180 . The movement of the hinge assembly  114   b  imparts movement of the retention structure  116   b  (and any additional retention structures passing through the hinge assembly  114   b ). 
     As shown in the enlarged view, the segment  104   a  shifts by an angular distance  131  relative to the segment  104   a  in  FIG.  8   . The angular distance  131 , allowed by the movement of the hinge assembly  114   b , may cause additional changes to the retention structure  116   b . For instance, the length of the retention structure  116   b  (and any additional retention structures passing through the hinge assembly  114   b ) may increase on the order of 50-100 micrometers or more. This length increase of the retention structure  116   b  may increase the tension of the retention structure  116   b , and the material properties of the retention structure  116   b  may cause the retention structure  116   b  to resist the length increase. As a result, the frictional forces between structural components, such as roller elements and spacer elements, of the hinge assembly  114   b  increase. The increased frictional forces increase the torque required to move hinge assembly  114   b . The increased torque of the hinge assembly  114   b  can provide additional support, or holding force, for the electronic device  180 . Accordingly, the properties and characteristics of the hinge assembly  114   b  are dynamic, and depend upon the position of the accessory device  100 . It should be noted that any retention structure not shown in  FIGS.  8  and  9    that passes through the hinge assembly  114   b  undergo similar changes and provide similar features as those of the retention structure  116   b.    
       FIG.  10    illustrates a side view of the accessory device  100 , showing the accessory device  100  carrying the electronic device  180  in a closed position. As shown, the accessory device  100  is generally upright such that forces (including gravitational forces) may act on the accessory device  100  to otherwise cause the section  102   a  and the section  102   b  to separate from each other. However, the hinge assembly  114   a  is designed to withstand these forces to keep the accessory device  100  in the closed position. For instance, the retention structure  116   a  may causes the structural components, such as roller elements and spacer elements (discussed below), to frictionally engage each other in a manner that provides the hinge assembly  114   a  sufficient torque to resist gravitational forces. As a result, only user interaction with the accessory device  100  causes the accessory device  100  to transition out of the closed position. Although not shown in  FIG.  10   , one or more retentions structures may pass through the hinge assembly  114   b  to provide support and maintain the hinge assembly  114   b  in a flat configuration. 
       FIG.  11    illustrates an exploded view of components of a hinge assembly  214 , in accordance with some described embodiments. The hinge assembly  214 , including its components and associated features, may represent any hinge assembly described herein. As shown, the hinge assembly  214  includes a roller element  232  and a spacer element  234 . The roller element  232  defines a cylindrical, or at least substantially cylindrical, body. However, other shapes are possible. The spacer element  234  can be positioned between the roller element  232  and an additional roller element (not shown in  FIG.  8   ), thereby providing a link, or linking element, between adjacent roller elements. The spacer element  234  may include a surface  236   a  and a surface  236   b  (opposite the surface  236   a ). The surface  236   a  and the surface  236   b  each define a receiving surface for the roller element  232  and an additional roller element, respectively. Further, the surface  236   a  and the surface  236   b  may each take on a shape that corresponds to the shape of a roller element. During movement of the hinge assembly  214 , the roller element  232  (representative of additional roller elements) is designed to rotate, or roll, along the surface  236   a  of the spacer element  234  (representative of additional spacer elements). 
     As shown in the enlarged view, the roller element  232  may include a cylindrical body  238  and a coating  242  that covers the cylindrical surface defined by the cylindrical body  238 . In some embodiments, the cylindrical body  238  includes a metal such, as steel (including stainless steel) or aluminum (including anodized aluminum). In order to prevent or reduce wearing of the cylindrical body  238 , the coating  242  may cover (fully cover or at least substantially cover) the cylindrical body  238 . The coating  242  may include polyetheretherketone (PEEK) filled w/polytetrafluoroethylene (Teflon™), graphite, carbon fiber, perfluoroalkoxy copolymer resin (PFA Teflon™), or other similar materials. Also, the coating  242  may include a thickness of 1 millimeter or less. The coating  242  may include a thickness on the order of several hundred micrometers, and the visibility of the coating  242  is somewhat minimal. In this regard, the roller element  232  may include a cylindrical body  238  with a relatively high structural rigidity that is protected from wear based on the coating  242  that is generally not viewable by a user. Also, the spacer element  234  may include any material(s) described for the roller element  232 . 
     When mated with the surface  236   a , the roller element  232  is partially interlocked with the spacer element  234 . For example, the roller element  232  may include a cavity  244   a  and a cavity  244   b  that receive a protrusion  246   a  and a protrusion  246   b , respectively, located along the surface  236   a  of the spacer element  234 . Although the roller element  232  is partially interlocked with the spacer element  234 , at least some freedom of movement is allowed by the roller element  232  relative to the spacer element  234 . Although not labeled, the roller element  232  includes additional cavities for protrusions of an additional spacer element (not shown in  FIG.  8   ), and the spacer element  234  includes additional protrusion located on the surface  236   b  for cavities of an additional roller element (not shown in  FIG.  8   ). 
     In order to further maintain engagement between roller elements and spacer elements, the hinge assembly  214  may include retention structures, or straps. For example, the hinge assembly  214  includes a retention structure  216   a , a retention structure  216   b , and a retention structure  216   c . The aforementioned retention structure may include a metal, fabric, a combination of metal and fabric, or generally any sturdy, yet flexible material. The retention structure  216   a  passes through an opening  252   a  (or through hole) of the spacer element  234  and an opening  254   a  of the roller element  232 . The retention structure  216   b  passes through an opening  252   b  of the spacer element  234  and an opening  254   b  of the roller element  232 . The retention structure  216   c  passes through an opening  252   c  of the spacer element  234  and an opening  254   c  of the roller element  232 . The retention structures can be fastened or secured to sections or segments of an accessory device (not shown in  FIG.  8   ). Further, the retention structures can be pulled or stretched in order to increase tension, which in turns causes an increased frictional force between the roller element  232  and the spacer element  234  (as well as increased frictional forces between additional roller elements and spacer elements of the hinge assembly  214  that are not shown). Even further, the retention structures can be fastened or secured to tensioning elements, including adjustable tensioning elements, which can be used to adjust the frictional forces between the roller element  232  and the spacer element  234  (as well as adjust the frictional forces between additional roller elements and spacer elements of the hinge assembly  214  that are not shown). As a result, the ability for the hinge assembly  214  to hold the weight of the sections, segments, and an electronic device (not shown in  FIG.  8   ) can be controlled in part by the frictional forces that depend upon the use of at least one of the retention structure  216   a , the retention structure  216   b , and the retention structure  216   c.    
     It should be further noted that the retention structure  216   a , the retention structure  216   b , and the retention structure  216   c  can provide additional features. For example, the retention structure  216   a  can provide the tension, which dictates frictional forces between roller elements and spacer elements, while the retention structure  216   b  can be relatively rigid (compared to the retention structure  216   a  and the retention structure  216   c ) in order to provide an additional stiffness and holding force by the hinge assembly  214 . Further, the retention structure  216   c  may include a flexible circuit that passes electrical communication between an electronic device and an input mechanism of an accessory device (not shown in  FIG.  8   ). Also, the number of retention features may vary based on the number of features required. 
       FIGS.  12  and  13    illustrate an accessory device  300  with a hinge assembly  314 , taken along different cross sections. The hinge assembly  314 , including its components and associated features, may represent any hinge assembly described herein. 
       FIG.  12    illustrates a cross sectional view of an embodiment of an accessory device  300 , showing a hinge assembly  314  and a retention structure  316  passing through the hinge assembly  314 , in accordance with some described embodiments. As shown, the accessory device  300  is generally in a closed position, similar to what is shown in  FIG.  4   . The retention structure  316  passes through an opening in each spacer element and each roller element, and further extends into a section  302   a  and a section  302   b  of the accessory device  300 . The retention structure  316  can be fastened to the section  302   a  and the section  302   b , or a tensioning system (not shown in  FIG.  9   ) located in the section  302   a  and/or the section  302   b.    
     In addition to the retention structure  316 , the hinge assembly  314  may include a roller element  332   a , a spacer element  334   a , a roller element  332   b , and a spacer element  334   b . The roller element  332   a  is engaged with a curved surface of the section  302   a  as well as a surface of the spacer element  334   a . The roller element  332   b  is engaged with the spacer element  334   a  and the spacer element  334   b . The roller element  332   a  is designed to at least partially rotate along a surface of the spacer element  334   a  and the section  302   a , and the roller element  332   b  is designed to at least partially rotate along a surface of the spacer element  334   a  and the spacer element  334   b . The retention structure  316  is designed to maintain frictional engagement between the roller elements and the spacer elements, which may not be permanently affixed together by fasteners, adhesives, or the like. As a result, the retention structure  316  can regulate movement of the hinge assembly  314 , and confine the movement of the hinge assembly  314  to certain positions. 
     In addition to the retention structure  316 , the hinge assembly  314  may include additional feature designed to regulate movement. For example,  FIG.  13    illustrates a cross sectional view of the accessory device  300  shown in  FIG.  9   , showing the hinge assembly  314  and components the hinge assembly  314  interlocked. As shown, the roller element  332   a  includes a cavity  344   a  and the section  302   a  includes a protrusion  346   a  positioned in the cavity  344   a . The roller element  332   a  further includes a cavity  344   b  and the spacer element  334   a  includes a protrusion  346   b  positioned in the cavity  344   b . The roller element  332   b  includes a cavity  344   c  and the spacer element  334   b  includes a protrusion  346   c  positioned in the cavity  344   d . The roller element  332   b  further includes a cavity  344   d  and the spacer element  334   b  includes a protrusion  346   d  positioned in the cavity  344   d.    
     As shown in  FIG.  13   , the protrusions are positioned in the cavities and are engaged with surfaces that define the cavities. As a result, further movement of the hinge assembly  314  may be limited or prevented. For example, based on the physical contact between the protrusions and the surfaces within the cavities, the section  302   a  may not be permitted to travel toward the section  302   b  in the direction of an arrow  355   a . However, when the section  302   a  moves away from the section  302   b  in the direction of an arrow  355   b , the protrusions are no longer engaged with surfaces that define the cavities. 
       FIG.  14    illustrates an isometric view of an alternate embodiment of a spacer element  434 , showing the spacer element  434  with inserts that include protrusions that extend in different directions, in accordance with some described embodiments. The spacer element  434  (and several additional spacer elements with features similar to the spacer element  434 ) may be integrated with hinge assemblies described herein. The spacer element  434  includes an insert  466   a  and an insert  466   b , each of which includes multiple protrusions designed to interact with a roller element(s) (not shown in  FIG.  14   ) to control the movement of a hinge assembly. The protrusions of the insert  466   a  and the insert  466   b  include structural features similar to the protrusion  346   a , the protrusion  346   b , and the protrusion  346   c  (shown in  FIG.  13   ). However, the insert  466   a  and the insert  466   b  may include additional benefits, including the ability to control the movement of a hinge assembly in different directions. This will be further discussed below. 
     The insert  466   a  and the insert  466   b  each include protrusions positioned at a diagonal (non-zero angle) relative to a surface of the spacer element  434  through which the protrusions protrude. However, the protrusions of the insert  466   a  may be positioned an angle different than the protrusions of the insert  466   b . By providing an insert  466   a  with protrusions directed at one angle and an insert  466   b  at another angle, the spacer element  434  may provide a hinge assembly with mechanical stops at two different positions. For example, the insert  466   a  may provide a mechanical stop for a hinge assembly in a closed position of an accessory device, and the insert  466   b  may provide a mechanical stop for a hinge assembly in an open position of an accessory device. The phrases “open position” and “closed position” for an accessory device are previously described. The insert  466   a  and the insert  466   b  may include a symmetric design. In this manner, while  FIG.  14    shows the insert  466   a  and the insert  466   b  protruding from a surface  436   a  of the spacer element  434 , the insert  466   a  and the insert  466   b  may include an additional matching number of protrusions (not shown in  FIG.  14   ) that protrude from a surface  436   b  of the spacer element  434  that is opposite the surface  436   a.    
     In addition to having openings for the inserts, the spacer element  434  may include openings, or through holes, with each opening designed to receive a retention structure (not shown in  FIG.  14   ). For example, the spacer element  434  includes an opening  452   a , an opening  452   b , and an opening  452   c . The number of openings of the spacer element  434  may vary based upon the number of retention structures used with a hinge assembly. 
       FIG.  15    illustrates an isometric view of the spacer element shown in  FIG.  14   , showing the inserts prior to installing in the spacer element  434 . As shown, the spacer element  434  includes a slot  453   a  and a slot  453   b  that receives the insert  466   a  and the insert  466   b , respectively. The insert  466   a  and the insert  466   b  represent modular inserts that can be manufactured (including molding and/or machining, as non-limiting examples) prior to integration with the spacer element  434 . In other words, the insert  466   a  and the insert  466   b  are initially separate from the spacer element  434 , and subsequently positioned into openings (not labeled) of the spacer element  434  and secured through means such as adhesives, welding, soldering, press fitting, interference fitting, or a combination thereof. By pre-fabricating the insert  466   a  and the insert  466   b , the tolerances can be reduced and the ease of manufacture of the protrusions of the insert  466   a  and the insert  466   b  are enhanced, as compared to machining a single piece of material to form a spacer element with integrated protrusions. Also, the insert  466   a  and the insert  466   b  each represent a single body with multiple protrusions, as opposed to multiple, separate protrusions. While an alternative embodiment (not shown) may include multiple, separate protrusion, the single-body style (of the insert  466   a  and the insert  466   b ) that carries multiple protrusions reduce assembly times. 
       FIG.  16    illustrates a cross sectional view of the spacer element  434  shown in  FIG.  14   , taken along line  16 - 16 , showing the insert  466   a  positioned in the spacer element  434 . As shown, the insert  466   a  includes a protrusion  446   a  and a protrusion  446   b  (as well as several similar protrusions that are not shown). The protrusion  446   a  and the protrusion  446   b  are generally diagonal. Further, the protrusion  446   a  and the protrusion  446   b  are directed toward a first portion  435   a , or lower portion, of the spacer element  434 . Based the configuration of the protrusion  446   a  and the protrusion  446   b  (and additional protrusions of the insert  466   a ), the insert  466   a  may limit or prevent movement of a hinge assembly that integrates the spacer element  434 . This will be further shown below. Also, in order to enhance the integration of the insert  466   a  into the spacer element  434 , the protrusion  446   a  and the protrusion  446   b  (as well as remaining protrusion of the insert  466   a ) may include a chamfered edge  447   a  and a chamfered edge  447   b , respectively. 
       FIG.  17    illustrates a cross sectional view of the spacer element shown in  FIG.  14   , taken along line  17 - 17 , showing the insert  466   b  positioned in the spacer element  434 . As shown, the insert  466   b  includes a protrusion  446   c  and a protrusion  446   d . The protrusion  446   c  and the protrusion  446   d  are generally diagonal. However, the protrusion  446   c  and the protrusion  446   d  are directed toward a second portion  435   b , or upper portion, of the spacer element  434 . The second portion  435   b  is opposite the first portion  435   a  (shown in  FIG.  16   ). Based the configuration of the protrusion  446   c  and the protrusion  446   d  (and additional protrusions of the insert  466   b ), the insert  466   b  may limit or prevent movement of a hinge assembly that integrates the spacer element  434 . Moreover, the insert  466   b  may limit or prevent movement of the hinge assembly in a direction (or position) that is different from the direction (or position) limited or prevented by the insert  466   a  (shown in  FIG.  16   ). This will be further shown below. 
     The protrusions shown and described in  FIGS.  16  and  17    may include a dovetail configuration. For example, the protrusion  446   a  and the protrusion  446   b  (shown in  FIG.  16   ), as well as the protrusion  446   c  and the protrusion  446   d  (shown in  FIG.  17   ), may taper, or flare. This may enhance the interlocking, and subsequent stopping, capabilities of the protrusions. However, it should be noted that other shapes for the protrusions, such as rectangular shapes, are possible. 
       FIGS.  18 - 21    show and describe a hinge assembly with spacer elements that includes features and components previously described for the spacer element  434  (shown in  FIG.  14   ). Although the spacer elements are integrated with a particular hinge assembly, the spacer elements may be integrated with any hinge assembly of an accessory device described herein. 
       FIG.  18    illustrates a cross sectional view of a hinge assembly  514 , in accordance with some described embodiments. As shown, the hinge assembly  514  may include a roller element  532   a , a roller element  532   b , and a roller element  532   c . The hinge assembly  514  may further include a spacer element  534   a  and a spacer element  534   b , with an insert  566   a  and an insert  566   c  integrated with the spacer element  534   a  and the spacer element  534   b , respectively. The insert  566   a  includes a protrusion  546   a  and a protrusion  546   b  located in a cavity  544   a  (of the roller element  532   a ) and a cavity  544   b  (of the roller element  532   b ), respectively. Also, the insert  566   c  includes a protrusion  546   c  and a protrusion  546   d  located in a cavity  544   c  (of the roller element  532   b ) and a cavity  544   d  (of the roller element  532   c ), respectively. 
     As shown, the aforementioned protrusions are not engaged, or in contact with, surfaces that define the aforementioned cavities. As a result, the roller elements can rotate (along concave surfaces of the spacer elements) relative to the spacer elements, or conversely, the spacer elements can rotate (along rounded surfaces of the roller elements) relative to the roller elements. However, once the protrusions contact the surfaces (that define the cavities), the hinge assembly  514  can prevent further movement of accessory device from further movement. 
       FIG.  19    illustrates a side view of an accessory device  500  with the hinge assembly  514  shown in  FIG.  18    integrated with the accessory device  500 . As shown, the accessory device  500  is in a closed position, and the hinge assembly  514  connects a segment  504   a  of the accessory device  500  with a segment  504   b  of the accessory device  500 . Further, as shown in the enlarged cross sectional view, the protrusions of the inserts are engaged with the roller elements. For example, the accessory device  500 , in the closed position, causes movement of the hinge assembly  514  such that the protrusion  546   a  and the protrusion  546   b  engage the roller element  532   a  and the roller element  532   b , respectively, within the respective cavities of the roller element  532   a  and the roller element  532   b . Also, the closed position of the accessory device  500  further causes the protrusion  546   c  and the protrusion  546   c  to engage the roller element  532   b  and the roller element  532   c , respectively, within the respective cavities of the roller element  532   b  and the roller element  532   c . As a result, the segment  504   a  is prevented from further movement toward a section  502   b  of the accessory device  500 . Also, the accessory device  500  further includes a hinge assembly  514   a  that connects the segment  504   b  with the section  502   b . The hinge assembly  514   a  may include any features described for the hinge assembly  514 . 
       FIG.  20    illustrates a cross sectional view of the hinge assembly  514  shown in  FIG.  18   , showing the spacer elements with additional inserts, in accordance with some described embodiments. As shown, the spacer element  534   a  and the spacer element  534   b  may further include an insert  566   b  and an insert  566   d , respectively. The insert  566   d  includes a protrusion  546   e  and a protrusion  546   f  located in a cavity  544   e  (of the roller element  532   a ) and a cavity  544   f  (of the roller element  532   b ), respectively. Also, the insert  566   d  includes a protrusion  546   g  and a protrusion  546   h  located in a cavity  544   g  (of the roller element  532   b ) and a cavity  544   h  (of the roller element  532   c ), respectively. Also, it should be noted that the roller element  532   a , the roller element  532   b , and the roller element  532   c  each include multiple openings to accommodate multiple inserts, and their accompanying protrusions. As an example, the roller element  532   b  may include a four openings dedicated to the inserts, with an assigned opening for the insert  566   a  and the insert  566   c  (shown in  FIG.  18   ), as well as the insert  566   b  and the insert  566   c.    
     The spacer element  534   a  carries the insert  566   a  (shown in  FIG.  18   ) and the insert  566   b , and the spacer element  534   b  carries the insert  566   c  (shown in  FIG.  18   ) and the insert  566   d . However, the protrusion  546   e  and the protrusion  546   f  of the insert  566   b  are oriented toward a direction that is generally opposite to that of the protrusion  546   a  and the protrusion  546   b  of the insert  566   a  (shown in  FIG.  18   ). Further, the protrusion  546   g  and the protrusion  546   h  of the insert  566   d  are oriented toward a direction that is generally opposite to that of the protrusion  546   c  and the protrusion  546   d  of the insert  566   c  (shown in  FIG.  18   ). This configuration allows the spacer element  534   a  and the spacer element  534   b  are to limit or prevent movement of the hinge assembly  514  in two different directions. Accordingly, the hinge assembly  514  can limit or prevent movement of an accessory device (that integrates the hinge assembly  514 ) in two different positions, such as a closed position (shown in  FIG.  19   ) and open position (discussed below). 
     While the aforementioned protrusions are not engaged, or in contact with, surfaces that define the aforementioned cavities (as shown in  FIG.  20   ), the roller elements can rotate (along concave surfaces of the spacer elements) relative to the spacer elements, or conversely, the spacer elements can rotate (along rounded surfaces of the roller elements) relative to the roller elements. However, once the protrusions contact the surfaces (that define the cavities), the hinge assembly  514  can prevent further movement of accessory device components from further movement. 
       FIG.  21    illustrates a side view of the accessory device  500  shown in  FIG.  19   , showing the accessory device  500  further limited in movement based on the hinge assembly  514 . As shown, the accessory device  500  is in an open position. Further, as shown in the enlarged cross sectional view, the protrusions of the inserts are engaged with the roller elements. For example, the accessory device  500  in the open position causes movement of the hinge assembly  514  such that the protrusion  546   e  and the protrusion  546   f  engages the roller element  532   a  and the roller element  532   b , respectively, within the respective cavities of the roller element  532   a  and the roller element  532   b . Also, the open position of the accessory device  500  further causes the protrusion  546   g  and the protrusion  546   h  to engage the roller element  532   b  and the roller element  532   c , respectively, within the respective cavities of the roller element  532   b  and the roller element  532   c . As a result, the segment  504   a  is prevented from further movement away from the section  502   b . Also, the hinge assembly  514   a  may include any features described for the hinge assembly  514  shown in  FIGS.  20  and  21   . 
       FIG.  22    illustrates a cross sectional view of an embodiment of a roller element  632  for use with a hinge assembly, in accordance with some described embodiments. As shown, the roller element  632  includes an opening  654  that may receive, for example, a retention structure (not shown in  FIG.  22   ). The opening  654  may be defined by multiple surfaces. For example, the opening  654  includes a surface  656   a  and a surface  656   b . The surface  656   a  is generally flat or planar, while the surface  656   b  is curved or contoured. As shown, the surface  656   b  defines a convex surface. When integrated into a hinge assembly (not shown in  FIG.  22   ), the roller element  632  can rotate such that the surface  656   b  engages a retention structure in certain positions and configurations of the hinge assembly. 
       FIG.  23    illustrates a cross sectional view of an embodiment of an accessory device  700 , showing a hinge assembly  714  and a retention structure  716  passing through the hinge assembly  714 , in accordance with some described embodiments. The roller elements of the hinge assembly  714  may include a convex surface, similar to the surface  656   b  of the roller element  632  (shown in  FIG.  22   ). Further, the spacer elements, such as a spacer element  734 , of the hinge assembly  714  may include a convex surface, similar to the surface  656   b  of the roller element  632  (shown in  FIG.  22   ). The hinge assembly  714  includes a roller element  732  with an opening  754  that includes a surface  756   a  and a spacer element  734  with an opening  752  that includes a surface  756   b . These surfaces, and remaining surfaces of the openings in the roller elements and the spacer elements, may be similar to the surface  656   b  (shown in  FIG.  22   ). In this manner, each surface may include a convex surface designed to engage the retention structure  716 , as shown in  FIG.  23   . 
       FIG.  24    illustrates an isometric view of an embodiment of a retention structure  816  with a shim structure  817 , in accordance with some described embodiments. The retention structure  816  may include any features described herein for a retention structure. Also, the retention structure  816  may substitute for other retention structures described herein. The shim structure  817  (shown primarily as a dotted line) is positioned on a surface of the retention structure  816 , and provides additional volume to the retention structure  816 . In particular, the shim structure  817  may increase the retention structure  816  in a particular dimension. The shim structure  817  can be adhesively coupled to the retention structure  816 , or secured by other means. The shim structure  817  may include tape, as a non-limiting example. Generally, the thickness of the shim structure  817  is less than that of the retention structure  816 . However, the relationship related to the thickness may vary. 
       FIGS.  25  and  26    show and describe an accessory device  800  with a hinge assembly  814  that includes the retention structure  816  (shown in  FIG.  24   ). Further,  FIGS.  25  and  26    show movement of the retention structure  816  during movement of the hinge assembly  814  (and the accessory device  800 ). 
       FIG.  25    illustrates a cross sectional view of an embodiment of an accessory device  800  with a hinge assembly  814 , showing the retention structure  816  and the shim structure  817  integrated with the hinge assembly  814 , in accordance with some described embodiments. As shown, the hinge assembly  814  positions the accessory device  800  at an angle that is greater than 90 degrees. In some instances, a retention structure may disengage from any one of the roller element  832   a , the roller element  832   b , and the roller element  832   c  of the hinge assembly  814 . During the disengagement, the torque required to move the hinge assembly  814  changes, and as a result the force required to transition the accessory device  800  also changes. This may lead to an inconsistent transition of the accessory device  800 . However, due in part to the shim structure  817 , the retention structure  816  remains engaged with the aforementioned roller elements during a transition of the accessory device  800 , and the torque required to move the hinge assembly  814  remains unchanged. Accordingly, the torque profile (of the hinge assembly  814 ) is consistent, predictable, and repeatable, and a user experiences little or no changes in the hinge assembly  814  when transitioning the accessory device  800 . Also, in some instances, the retention structure  816  undergoes a pre-bending operation or a tensioning operation. The shim structure  817  nonetheless provides the engagement with the roller elements. 
       FIG.  26    illustrates a cross sectional view of the accessory device  800  shown in  FIG.  25   , showing the hinge assembly  814  positioning the accessory device  800  at a different angle. As shown, the accessory device  800  is generally flat such that two sections of the accessory device  800  are planar and define a 180-degree angle. Despite the retention structure  816  being flat, the retention structure  816  (by way of the shim structure  817 ) remains engaged with the roller element  832   a , the roller element  832   b , and the roller element  832   c  during a transition of the accessory device  800 , and the torque required to move the hinge assembly  814  remains unchanged. 
     In some instances, however, it may be advantageous to allow a retention structure (or structures) to disengage from the components of a hinge assembly. For example,  FIG.  27    illustrates a cross sectional view of an alternate embodiment of an accessory device  900  and a hinge assembly  914 , showing the hinge assembly  914  positioning the accessory device at an angle greater than 180 degrees, in accordance with some described embodiments. As shown, the hinge assembly  914  includes a roller element  932   a , a roller element,  932   b , and a roller element  932   c . The hinge assembly  914  further includes a retention structure  916  that passes through the aforementioned roller elements. As shown, in an initial position of the hinge assembly  914 , the retention structure  916  engages the roller element  932   a , the roller element,  932   b , and the roller element  932   c . However, during a transition to a subsequent position (shown as dotted lines) to an angle  931  beyond the 180-degree angle, the retention structure  916  disengages with at least the roller element  932   b . During this instance of disengagement, the torque profile of the hinge assembly  914  changes. For example, the external force or torque (provided by a user) required to move the hinge assembly  914  may decrease, which may facilitate transitioning the hinge assembly  914  (and in turn, the accessory device  900 ) from one position to another. The initial torque profile (prior to disengagement of the retention structure  916  with the roller element(s)) returns once the retention structure  916  engages the roller element(s). Accordingly, the torque profile of hinge assembly  914  provides at least two positions of equal torque when, with a different (e.g., smaller) torque when the retention structure  916  disengages with at least one of the roller elements. 
       FIG.  28    illustrates a cross sectional view of an alternate embodiment of a roller element  632  for use with a hinge assembly, in accordance with some described embodiments. As shown, the roller element  1032  includes an opening  1054  that may receive, for example, a retention structure  1016 . The opening  1054  may be defined by multiple surfaces. For instance, the opening  1054  includes a surface  1056   a  that is generally flat or planar, as well as a surface that includes both a flat portion  1056   b  and a curved portion  1056   c . As shown, the curved portion  1056   c  includes a non-linear surface. Generally, the curved portion  1056   c  may include a different slope/curvature, as compared to the flat portion  1056   b . As an example, in some embodiments, the curved portion  1056   c  includes a diagonal, or sloped, configuration with respect to the flat portion  1056   b . When integrated into a hinge assembly (not shown in  FIG.  28   ), the roller element  1032  is positioned such that the flat portion  1056   b  engages, or at least partially engages, the retention structure  1016 . 
     Based on the dimensions of the opening  1054 , the retention structure  1016  may apply additional torque to the roller element  1032 , which in turn applies additional torque to a hinge assembly that includes the roller element  1032 . For example, when the retention structure  1016  is parallel, or approximately parallel, to the flat portion  1056   b , the retention structure  1016  can apply a given torque to the roller element  1032 . However, as shown in  FIG.  2   , when the retention structure  1016  is non-parallel to the flat portion  1056   b  by an angle  1030  (non-zero angle relative to a horizontal line), the retention structure  1016  can rotate toward the curved portion  1056   c  and apply additional torque to the roller element  1032 . The additional torque provided to a hinge assembly by the retention structure  1016  may be used to support, or counterbalance, additional weight provided an electronic device carried by an accessory device (not shown in  FIG.  28   ) that includes the roller element  1032  and the retention structure  1016 . It should be noted that the opening  1054  (shown in  FIG.  28   ) and the opening  1054  each define an asymmetric opening, in which two surfaces facing each other are significantly different from each other. 
     Also, by adjusting the angle  1030 , the torque provided by the retention structure  1016  to the roller element  1032  can also change. For instance, by increasing the angle  1030  (i.e., making the angle larger), the surface defined by the curved portion  1056   c  becomes steeper than what is shown for the curved portion  1056   c  in  FIG.  28   . As a result, the retention structure  1016  (when engaging the curved portion  1056   c ) can provide additional torque to the roller element  1032  when tension is applied to the retention structure  1016 . Conversely, by decreasing the angle  1030  (i.e., making the angle smaller), the surface defined by the curved portion  1056   c  becomes shallower than what is shown for the curved portion  1056   c  in  FIG.  28   . As a result, the retention structure  1016  (when engaging the curved portion  1056   c ) can provide a reduced torque to the roller element  1032  when same tension is applied to the retention structure  1016 . 
       FIG.  29    illustrates a cross sectional view of an embodiment of an accessory device  1100 , showing a hinge assembly  1114  and a retention structure  1116  passing through the hinge assembly  1114 , in accordance with some described embodiments. As shown, the hinge assembly  1114  includes a roller element  1132   a , a roller element  1132   b , and a roller element  1132   c . Some of the roller elements of the hinge assembly  1114  may include a flat portion and a diagonal portion, similar to the flat portion  1056   b  and the curved portion  1056   c , respectively, of the roller element  1032  (shown in  FIG.  28   ). For example, the roller element  1132   a  and the roller element  1132   c  each include a flat portion and a diagonal portion. However, the respective diagonal portions of the roller element  1132   a  and the roller element  1132   c  face the roller element  1132   b  such that the roller element  1132   a  and the roller element  1132   c  are mirror images of each other, in terms of their respective cross sections. The roller element  1132   b , located between the roller element  1132   a  and the roller element  1132   c , includes a convex surface  1156  (similar to the surface  656   b , shown in  FIG.  22   ). As shown, the accessory device  1100  is supporting an electronic device  1180 , similar to the configuration of the accessory device  100  and the electronic device  180  (shown in  FIG.  3   ). By providing roller elements of the hinge assembly  1114  with an engagement surface (for the retention structure  1116 ) with both a flat portion and a diagonal portion, the retention structure  1116  can provide additional torque to the hinge assembly  1114 . In this manner, the hinge assembly  1114  is better suited to support the electronic device  1180  as well as a segment and/or section of the accessory device  1100  that supports the weight of the electronic device  1180 . Further, some roller elements can be designed to provide full clearance between a spacer element and the retention structure  1116 . For example, the roller element  1132   a  and a roller element  1132   b  are designed such that in the position (of the hinge assembly  1114 ) shown in  FIG.  29   , a spacer element  1134  (between the roller element  1132   a  and the roller element  1132   b ) is not in contact with the retention structure  1116 . However, in other positions of the hinge assembly  1114 , the spacer element  1134  is contact with the retention structure  1116 . 
       FIG.  30    illustrates a side view of an alternate embodiment of an accessory device  1200 , showing a retention structure  1216  passing through multiple hinge assemblies, in accordance with some described embodiments. As shown, the accessory device  1200  includes a section  1202   a  and a section  1202   b  connected to the section  1202   a  by a hinge assembly  1214   a , thereby allowing relative rotational movement between the section  1202   a  and the section  1202   b . The section  1202   a  further includes a segment  1204   a  and a segment  1204   b  connected to the segment  1204   a  by a hinge assembly  1214   b , thereby allowing relative rotational movement between the segment  1204   a  and the segment  1204   b.    
     As shown in the enlarged cross sectional view, the retention structure  1216  passes through both the hinge assembly  1214   a  and the hinge assembly  1214   b . This may promote synchronous movement of the hinge assembly  1214   a  and the hinge assembly  1214   b . The accessory device  1200  may additional features designed to further promote movement of the hinge assembly  1214   a  and the hinge assembly  1214   b . For example, the accessory device  1200  may include an automated system  1262 . The automated system  1262  may include a motor (including a step motor), a spring-loaded mechanism, and/or a cam mechanism. The automated system  1262  is designed adjust the tension of the retention structure  1216 . For instance, the automated system  1262  can provide a pulling force that increases the tension on the retention structure  1216 . The automated system  1262  can also release the pulling force, thereby decreasing at least some of the tension on the retention structure  1216 . The accessory device  1200  may include an internal power supply (not shown in  FIG.  30   ), such as a battery, that provides energy to the automated system  1262 . Alternatively, the accessory device  1200  can receive energy from an internal power supply located in an electronic device (not shown in  FIG.  30   ) when the accessory device  1200  is coupled to the electronic device. The adjustment of the tension to the retention structure  1216  can adjust the frictional force between the roller elements and the spacer elements of the hinge assembly  1214   a  and the hinge assembly  1214   b . As a result, the accessory device  1200  can provide an adjustable mechanism that adjusts the degree to which the hinge assemblies can open and close, as well as how much force can be provided to hold an electronic device (not shown in  FIG.  30   ). Regarding the latter, the adjustment to the hinge assembly  1214   a  can adjust the degree to which the segment  1204   b  can withstand a force in the direction of an arrow  1255   a . Also, the adjustment to the hinge assembly  1214   b  can adjust the degree to which the segment  1204   a  can provide a counterbalance to offset a force in the direction of an arrow  1255   b . The accessory device  1200  may further include a button  1264  that can be operated by a user. The button  1264  may include a mechanical button that actuates a switch (not shown in  FIG.  30   ), or a button with a capacitive touch interface. The button  1264  is used to control the automated system  1262 . Accordingly, the button  1264  can control the retention structure  1216 , and in turn, control the frictional forces between the components of the hinge assembly  1214   a  and the hinge assembly  1214   b.    
       FIG.  31    illustrates a side view of an alternate embodiment of an accessory device  1300 , showing multiple hinge assemblies, each with a retention structure, in accordance with some described embodiments. As shown, the accessory device  1300  includes a section  1302   a  and a section  1302   b  connected to the section  1302   a  by a hinge assembly  1314   a , thereby allowing relative rotational movement between the section  1302   a  and the section  1302   b . The section  1302   a  further includes a segment  1304   a  and a segment  1304   b  connected to the segment  1304   a  by a hinge assembly  1314   b , thereby allowing relative rotational movement between the segment  1304   a  and the segment  1304   b.    
     As shown in the enlarged cross sectional view, the accessory device  1300  includes a retention structure  1316   a  that passes through the hinge assembly  1314   a , and a retention structure  1316   b  that passes through the hinge assembly  1314   b . The accessory device  1300  may include an automated system  1362   a  and an automated system  1362   b  connected to the retention structure  1316   a  and the retention structure  1316   b , respectively. The automated system  1362   a  and the automated system  1362   b  may include any feature(s) described for the automated system  1262  (shown in  FIG.  30   ). In this regard, the automated system  1362   a  and the automated system  1362   b  is designed adjust the tension of the retention structure  1316   a  and the retention structure  1316   b , respectively. The accessory device  1300  may include an internal power supply (not shown in  FIG.  31   ), such as a battery, that provides energy to the automated system  1362   a  and the automated system  1362   b . Alternatively, the accessory device  1300  can receive energy from an internal power supply located in an electronic device (not shown in  FIG.  31   ) when the accessory device  1300  is coupled to the electronic device. The automated system  1362   a  and the automated system  1362   b  can increase or decrease the tension on the retention structure  1316   a  and the retention structure  1316   b , respectively. Accordingly, the automated system  1362   a  and the automated system  1362   b  can adjust the frictional force between the roller elements and the spacer elements of the hinge assembly  1314   a  and the hinge assembly  1314   b , respectively. Moreover, the accessory device  1300  can provide an adjustable mechanism capable of individually adjusting the degree of frictional forces of each hinge assembly, which can adjust the stiffness of the hinge assemblies, as well as how much force can be provided to hold an electronic device (not shown in  FIG.  31   ) by the hinge assemblies. Regarding the latter, the adjustment to the hinge assembly  1314   a  can adjust the degree to which the segment  1304   b  can withstand a force in the direction of an arrow  1355   a . Also, the adjustment to the hinge assembly  1314   b  can adjust the degree to which the segment  1304   a  can provide a counterbalance to offset a force in the direction of an arrow  1355   b . The accessory device  1300  may further include a button  1364  that can be operated by a user. The button  1364  is used to control the automated system  1362   a  and the automated system  1362   b . Accordingly, the button  1364  can control the retention structure  1316   a  and the retention structure  1316   b , and in turn, control the frictional forces between components of the hinge assembly  1314   a  and the hinge assembly  1314   b , respectively. 
       FIG.  32    illustrates an exploded view of an alternate embodiment of a hinge assembly  1414 , showing the various components of the hinge assembly  1414 . As shown, the hinge assembly  1414  includes a roller element  1432   a , a roller element  1432   b , and a roller element  1432   c . The hinge assembly  1414  further includes a spacer element  1434   a  positioned between the roller element  1432   a  and the roller element  1432   b , as well as a spacer element  1434   b  positioned between the roller element  1432   b  and the roller element  1432   c . Although not shown, the hinge assembly  1414  may include additional features, such as retention structures (see the retention structure  216   a , the retention structure  216   b , and the retention structure  216   c  in  FIG.  11   ) as well as corresponding openings for the retention structures, as non-limiting examples. Also, although not shown, the hinge assembly  1414  may include additional roller and spacer elements. 
     Additionally, the hinge assembly  1414  may include a fastening component  1482   a , a fastening component  1482   b , and a fastening component  1482   c . The aforementioned fastening components may include a threaded fastener or threaded bolt, as non-limiting examples. The aforementioned fastening components couple with consecutive roller elements of the hinge assembly  1414 , and also pass through a spacer element. For instance, the fastening component  1482   a  includes an end that fits into an opening  1454   a  of the roller element  1432   a , as well as a threaded end that passes through an opening  1452   a  of the spacer element  1434   a  and into an opening  1454   c  of the roller element  1432   b . The roller element  1432   b  may include a threaded nut (not labeled) located in the opening  1454   c . In this manner, the threaded end of the fastening component  1482   a  can be in threaded engagement with the threaded nut. An example will be shown below. Similarly, the fastening component  1482   b  includes an end that fits into an opening  1454   d  of the roller element  1432   b , as well as a threaded end that passes through an opening  1452   b  of the spacer element  1434   a  and into an opening  1454   b  of the roller element  1432   a . The roller element  1432   a  may include a threaded nut (not labeled) located in the opening  1454   b  and capable of threaded engagement with the threaded end of the fastening component  1482   b . Also, the fastening component  1482   c  includes an end that fits into the opening  1454   d  of the roller element  1432   b , as well as a threaded end that passes through an opening  1452   c  of the spacer element  1434   b  and into an opening (not shown in  FIG.  32   ) of the roller element  1432   c . The roller element  1432   c  may include a threaded nut (not shown in  FIG.  32   ) located in the opening (that receives the threaded end of the fastening component  1482   c ), and capable of threaded engagement with the threaded end of the fastening component  1482   c.    
     Further, each of the fastening components may carry a tensioning element. For example, as shown in the enlarged view, the fastening component  1482   a  carries a tensioning element  1484   a . The tensioning element  1484   a  may include a flexible assembly, such as a spring or a washer (including a Belleville washer, as a non-limiting example). When the hinge assembly  1414  is assembled, the fastening components may be compressed by adjacent structures. For example, the tensioning element  1484   a  can be compressed by the roller element  1432   a  and the spacer element  1434   a . The compression of the tensioning element  1484   a  allows for frictional engagement between the roller element  1432   a  and the spacer element  1434   a . Moreover, an adjustment to the fastening component  1482   a  (e.g., rotating to tighten or loosen) can alter the compression to the tensioning element  1484   a , thereby adjusting the frictional engagement between the roller element  1432   a  and the spacer element  1434   a.    
       FIG.  33 A  illustrates a cross sectional view of the hinge assembly  1414  shown in  FIG.  32   , showing the elements of the hinge assembly  1414  secured together. As shown, the spacer element  1434   a  engages the roller element  1432   a  and the roller element  1432   b . Also, the spacer element  1434   b  engages the roller element  1432   b  and the roller element  1432   c . Additionally, the fastening component  1482   b  and the fastening component  1482   c  carry a tensioning element  1484   b  and tensioning element  1484   c , respectively. The tensioning element  1484   b  and the tensioning element  1484   c  may include any features described for the tensioning element  1484   a  (shown in  FIG.  32   ). In this regard, the tensioning element  1484   b  may be compressed between the spacer element  1434   a  and the roller element  1432   b , and the tensioning element  1484   c  may be compressed between the spacer element  1434   b  and the roller element  1432   b.    
     Further, the roller element  1432   a  includes a nut  1486   b  located in the opening  1454   b , and the roller element  1432   c  includes a nut  1486   c  located in an opening  1454   e  (of the roller element  1432   c ). In some embodiments, the nut  1486   b  and the nut  1486   c  each include a cylindrical perimeter, thereby defining a cylindrical nut. In the embodiment shown in  FIG.  33 A , the nut  1486   b  and the nut  1486   c  define a spherical perimeter, thereby defining a spherical nut. The nut  1486   b  and the nut  1486   c  are in threaded in engagement with the fastening component  1482   b  and the fastening component  1482   c , respectively. In some embodiments (not shown in  FIG.  33 A ), a surface of the nut  1486   b  and the nut  1486   c  are co-planar, or flush, with a surface of the roller element  1432   a  and the roller element  1432   c , respectively. For instance, an outer perimeter of the nut  1486   b  and the nut  1486   c  can be co-planar, or flush, with an outer perimeter of the roller element  1432   a  and the roller element  1432   c , respectively. In this manner, the nut  1486   b  and the nut  1486   c  can define a frictional engagement surface with the spacer element  1434   a  and the spacer element  1434   b , respectively. 
     When the hinge assembly  1414  is integrated with a system (such as the accessory device  100 , shown in  FIG.  1   ), at least some of the elements and components of the hinge assembly  1414  can move/rotate. For example,  FIG.  33 B  illustrates a cross sectional view of the hinge assembly  1414  shown in  FIG.  33 A , showing relative movement of some of the elements of the hinge assembly  1414 . As shown, the spacer element  1434   a  and the roller element  1432   a  can move relative to the roller element  1432   b , and vice versa, despite the integration of the fastening component  1482   b . Similarly, the spacer element  1434   b  and the roller element  1432   c  can move relative to the roller element  1432   b , and vice versa, despite the integration of the fastening component  1482   c . Also, in some embodiments, an additional nut is fitted in to the opening  1454   d  in order to secure the fastening component  1482   b  and the fastening component  1482   c.    
     It should be noted that while  FIGS.  33 A and  33 B  show and describe the hinge assembly  1414  as having a particular number of elements (e.g., roller elements, spacer elements, fastening components, nuts, etc.), the number of elements can increase or decrease in other embodiments based on the desired length and other characteristics of the hinge assembly  1414 . In other words, the hinge assembly  1414  shown and described in  FIGS.  33 A and  33 B  is an exemplary hinge assembly, and should not be construed as limiting. 
       FIG.  34    illustrates an isometric view of a roller element  1432   a  of the hinge assembly  1414  shown in  FIGS.  32 - 33 B , showing exemplary movement of the fastening component  1482   a . For purposes of illustration, the spacer element  1434   a  (shown in  FIGS.  32 - 34   ) is removed. During movement of the roller element  1432   a  relative to the spacer element  1434   a  (or vice versa), the fastening component  1482   a  can move in either direction defined by a two-sided arrow  1483 . However, the movement of the fastening component  1482   a  is limited based upon the dimensions of the opening  1454   a . For example, the fastening component  1482   a  can move in one of the directions defined by the two-sided arrow  1483  until the fastening component  1482   a  engages the edge of the opening  1454   a . Similarly, the fastening component  1482   a  can move in the other direction defined by the two-sided arrow  1483  until the fastening component  1482   a  engages the (opposing) edge of the opening  1454   a . Once the fastening component  1482   a  engages the edges of the opening  1454   a , further movement of the fastening component  1482   a . Additionally, further movement of the spacer element  1434   a  and the roller element  1432   b  (both shown in  FIGS.  32 - 33 B ) also ceases. Thus, the fastening components shown and described in  FIGS.  32 - 34    can be used for controlling movement of the hinge assembly  1414 . 
       FIG.  35 A  illustrates a cross sectional view of an alternate embodiment of a hinge assembly. The hinge assembly  1414 ′ may include any feature(s) shown and described for the hinge assembly  1414  (shown in  FIGS.  32 - 34   ). As shown, the spacer element  1434   a ′ engages the roller element  1432   a ′ and the roller element  1432   b ′. Also, the spacer element  1434   b ′ engages the roller element  1432   b ′ and the roller element  1432   c ′. Additionally, the fastening component  1482   b ′ and the fastening component  1482   c ′ carry a tensioning element  1484   b ′ and tensioning element  1484   c ′, respectively. In this regard, the tensioning element  1484   b ′ may be compressed between the spacer element  1434   a ′ and the roller element  1432   b ′, and the tensioning element  1484   c ′ may be compressed between the spacer element  1434   b ′ and the roller element  1432   b′.    
     Further, the roller element  1432   a ′ includes a nut  1486   b ′ located in the opening  1454   b ′, and the roller element  1432   c ′ includes a nut  1486   c ′ located in an opening  1454   e ′ (of the roller element  1432   c ′). In some embodiments, the nut  1486   b ′ and the nut  1486   c ′ each include a cylindrical perimeter, thereby defining a cylindrical nut. In the embodiment shown in  FIG.  35 A , the nut  1486   b ′ and the nut  1486   c ′ define a spherical perimeter, thereby defining a spherical nut. The nut  1486   b ′ and the nut  1486   c ′ are in threaded in engagement with the fastening component  1482   b ′ and the fastening component  1482   c ′, respectively. In some embodiments (not shown in  FIG.  35 A ), a surface of the nut  1486   b ′ and the nut  1486   c ′ are co-planar, or flush, with a surface of the roller element  1432   a ′ and the roller element  1432   c ′, respectively. For instance, an outer perimeter of the nut  1486   b ′ and the nut  1486   c ′ can be co-planar, or flush, with an outer perimeter of the roller element  1432   a ′ and the roller element  1432   c ′, respectively. In this manner, the nut  1486   b ′ and the nut  1486   c ′ can define a frictional engagement surface with the spacer element  1434   a ′ and the spacer element  1434   b ′, respectively. 
     When the hinge assembly  1414 ′ is integrated with a system (such as the accessory device  100 , shown in  FIG.  1   ), at least some of the elements and components of the hinge assembly  1414 ′ can move/rotate. For example,  FIG.  35 B  illustrates a cross sectional view of the hinge assembly  1414 ′ shown in  FIG.  35 A , showing relative movement of some of the elements of the hinge assembly  1414 ′. In some embodiments, the spacer element  1434   a ′ and the roller element  1432   a ′ can move relative to the roller element  1432   b ′, and vice versa, despite the integration of the fastening component  1482   b ′. Similarly, in some embodiments, the spacer element  1434   b ′ and the roller element  1432   c ′ can move relative to the roller element  1432   b ′, and vice versa, despite the integration of the fastening component  1482   c ′. However, in the embodiment shown in  FIG.  35 B , the roller element  1432   a ′ and the roller element  1432   c ′ move (i.e., rotate) relative to the spacer element  1434   a ′, the roller element  1432   b ′, and the spacer element  1434   b′.    
       FIG.  36    illustrates a cross sectional view of an alternate embodiment of a hinge assembly  1514 , showing the hinge assembly with multiple flexible components. As shown, the hinge assembly  1514  includes a roller element  1532   a , a roller element  1532   b , and a roller element  1532   c . The hinge assembly  1514  further includes a spacer element  1534   a  that engages the roller element  1532   a  and the roller element  1532   b , as well as a spacer element  1534   b  engages the roller element  1532   b  and the roller element  1532   c . Further, the spacer element  1534   a  carries a flexible member  1586   a  that extends out of the spacer element  1534   a  and into an opening  1554   a  of the roller element  1532   a . Additionally, the spacer element  1534   b  carries a flexible member  1586   b  that extends out of the spacer element  1534   b  and into an opening  1554   b  of the roller element  1532   b . The flexible member  1586   a  and the flexible member  1586   b  can be secured with the spacer element  1534   a  and the spacer element  1534   b , respectively, by welding, soldering, or adhesives, as non-limiting examples. Also, the flexible member  1586   a  and the flexible member  1586   b  may each include a leaf spring, and accordingly, the flexible member  1586   a  and the flexible member  1586   b  may include flexible properties. Although not shown, the hinge assembly  1514  may include additional features, such as retention structures (see the retention structure  216   a , the retention structure  216   b , and the retention structure  216   c  in  FIG.  11   ) as well as corresponding openings for the retention structures, as non-limiting examples. Also, although not shown, the hinge assembly  1514  may include additional roller and spacer elements. 
     The flexible member  1586   a  and the flexible member  1586   b  are each designed to bend or flex in response to a force (including a torque) derived from movement of the certain components of the hinge assembly  1514 . For example,  FIG.  37    illustrates a cross sectional view of the hinge assembly  1514  shown in  FIG.  36   , showing relative movement of some of the elements of the hinge assembly  1514 . When the roller element  1532   a  is rotated relative to the spacer element  1534   a  (or vice versa), the relative movement causes the flexible member  1586   a  to bend or flex. Similarly, when the roller element  1532   b  is rotated relative to the spacer element  1534   b  (or vice versa), the relative movement causes the flexible member  1586   b  to bend or flex. The bending/flexing of the flexible member  1586   a  and the flexible member  1586   b  increases the stiffness of the hinge assembly  1514 , thereby limiting the further movement of the hinge assembly  1514  to within two or more desired positions, and may also provide a force that returns the hinge assembly  1514  to the prior configuration (such as what is shown in  FIG.  36   ). Additionally, the flexible member  1586   a  and the flexible member  1586   b  may promote synchronous motion of the components of the hinge assembly  1514 . For example, as a result of the bending/flexing of the flexible member  1586   a  due to movement of the roller element  1532   a , the flexible member  1586   a  may bend but subsequently cease bending, and further torque provided to the roller element  1532   a  causes the spacer element  1534   a  to move/rotate, while also promoting movement/rotation of the roller element  1532   b  and the spacer element  1534   b . This may, concurrently, result in the bending/flexing of the flexible member  1586   b  until the spacer element  1534   b  and the roller element  1532   c  begin to move/rotate. 
       FIG.  38    illustrates an isometric view of an embodiment of a retention structure  1616 , showing several layers of materials secured with the ends of the retention structure  1616 . As shown, the retention structure  1616  includes several layers of materials on opposing ends (the retention structure  1616 ). Specifically, the retention structure  1616  includes layers of material  1688   a  and layers of material  1688   b . Each of the layers of material may include two or more layers of steel, including stainless steel (as a non-limiting example). In this manner, the layers of material  1688   a  and layers of material  1688   b  may more readily distribute loads applied to the retention structure  1616 , as compared to the material layer being formed from non-metal materials. In addition, the layers of material  1688   a  and layers of material  1688   b , each being formed from metal, may provide a more robust retention structure. This may be particularly useful when the retention structure  1616  is secured at its ends, which are defined by the layers of material  1688   a  and layers of material  1688   b . In this manner, the layer of material  1688   a  may define a structure that fits into a slot (not shown in  FIG.  38   ) and the layers of material  1688   b  may include an opening  1689  used to receive a fastener (not shown in  FIG.  38   ). Further details regarding integrating a retention structure similar to the retention structure  1616  may be found in, for example, in U.S. patent application Ser. No. 16/053,693, entitled FRICTION ROLLER HINGE FOR ELECTRONIC DEVICES AND METHOD FOR MAKING ROLLER AND SPACER ELEMENTS, which is incorporated by reference in its entirety herein. 
       FIG.  39    illustrates an isometric view of an alternate embodiment of a hinge assembly  1714 , showing several cables passing through a roller element  1732  of the hinge assembly  1714 . As shown, the roller element  1732  includes an opening  1754   a , an opening  1754   b , an opening  1754   c , and an opening  1754   d . The hinge assembly  1714  further includes a cable  1792   a , a cable  1792   b , a cable  1792   c , and a cable  1792   d  passing through the opening  1754   a , the opening  1754   b , the opening  1754   c , and the opening  1754   d , respectively. Generally, the aforementioned cables and openings each includes a circular cross section. Although not shown, the hinge assembly  1714  may include additional roller elements, as well as spacer elements (similar to spacer elements previously shown and described), with the additional roller elements and spacer elements having circular openings (similar to those shown and described for the openings of the roller element  1732 ) designed to receive a cable. 
       FIG.  40    illustrates a cross sectional view of a hinge assembly  1814 , showing a cable  1892  passing through several components of the hinge assembly  1814 . The hinge assembly  1814  may include features similar to those shown and described for the hinge assembly  1714  (shown in  FIG.  39   ). As shown, the hinge assembly  1814  includes a roller element  1832   a , a roller element  1832   b , and a roller element  1832   c . The hinge assembly  1814  further includes a spacer element  1834   a  that engages the roller element  1832   a  and the roller element  1832   b , as well as a spacer element  1834   b  engages the roller element  1832   b  and the roller element  1832   c . The hinge assembly  1814  further includes a cable  1892  passing through respective openings of the aforementioned roller elements and spacer elements. It should be noted that the cable  1892  may include flexible properties, thereby allowing relative movement of the components of the hinge assembly  1814 . 
     Referring to both  FIGS.  39  and  40   , the openings in the component(s) of the hinge assembly  1714  and the hinge assembly  1814  are relatively smaller than those previously shown and described for prior hinge assemblies. In this regard, the volume or space defined by the openings of the hinge assembly  1714  and the hinge assembly  1814  are relatively smaller. As a result, the locations of the spacer elements below and above the openings may include relatively more material, which may lead to a more reliable spacer element. This may be particularly beneficial when surrounding roller elements are compressing the spacer element. For instance, a spacer element (in prior embodiments) surrounded by, and in contact with, a pair of roller elements may be compressed by the roller elements, causing the spacer element to separate when sufficient compression force is applied, particularly at location(s) associated with an opening of the spacer element. However, when the spacer element  1834   a  is compressed by the roller element  1832   a  and the roller element  1832   b , the spacer element  1834   a  is less likely to separate along an opening  1852  of the spacer element  1834   a , due in part to the relatively smaller size of the opening  1852 , as compared to, for example, the opening  252   c  (shown in  FIG.  11   ). 
     In some embodiments, a cable(s) passing through a hinge assembly may be fastened or anchored to one end of a system or body, and coupled to another system or body by a spring. For example,  FIG.  41    illustrates a plan view of an alternate embodiment of a hinge assembly  1914 , showing several cables of the hinge assembly  1914 , with each cable connected to a flexible component. As shown, the hinge assembly  1914  includes a roller element  1932 . Although not shown, the hinge assembly  1914  may include additional roller elements, as well as spacer elements (similar to spacer elements previously shown and described), with the additional roller elements and spacer elements having circular openings (similar to those shown and described for the openings of the roller element  1932 ) designed to receive a cable. 
     The roller element  1932  includes several openings, with each opening receiving a cable. As shown, the hinge assembly  1914  includes a cable  1992   a , a cable  1992   b , a cable  1992   c , and a cable  1992   d . The hinge assembly  1914  further includes a flexible component  1994   a , a flexible component  1994   b , a flexible component  1994   c , and the flexible component  1994   d  connected to the cable  1992   a , the cable  1992   b , the cable  1992   c , and the cable  1992   d , respectively. The aforementioned flexible components may include a spring, as a non-limiting example. In this manner, the aforementioned flexible components allow for flexibility and variation in tension of the aforementioned cables, which may be beneficial when the hinge assembly  1914  is transitioning from one configuration/position to another. 
       FIG.  42    illustrates a plan view of an alternate embodiment of a hinge assembly  2014 , showing several cables of the hinge assembly, and further showing a flexible component coupled with the cables. As shown, the hinge assembly  2014  includes a roller element  2032 . Although not shown, the hinge assembly  2014  may include additional roller elements, as well as spacer elements (similar to spacer elements previously shown and described), with the additional roller elements and spacer elements having circular openings (similar to those shown and described for the openings of the roller element  2032 ) designed to receive a cable. 
     The roller element  2032  includes several openings, with each opening receiving a cable. As shown, the hinge assembly  2014  includes a cable  2092   a , a cable  2092   b , a cable  2092   c , and a cable  2092   d . The hinge assembly  2014  further includes a bar  2093  coupled with each of the aforementioned cables. The hinge assembly  2014  further includes a flexible component  2094  coupled with the bar  2093 , and accordingly, the flexible component  2094  is coupled with the aforementioned cables. As a result, the flexible component  2094  still allows for flexibility and variation in tension of the aforementioned cables, while also reducing the number of components for the hinge assembly  2014 . 
     Referring to both the hinge assembly  1914  and the hinge assembly  2014  in  FIGS.  41  and  42   , respectively, in some embodiments, the flexible component (or components) are coupled with both ends of the cables. 
       FIG.  43    illustrates a plan view of an alternate embodiment of a hinge assembly  2114 , showing a roller element  2132  and a cable  2192  passing through several openings of the roller element  2132 . Although not shown, the hinge assembly  2114  may include additional roller elements, as well as spacer elements (similar to spacer elements previously shown and described), with the additional roller elements and spacer elements having circular openings (similar to those shown and described for the openings of the roller element  2132 ) designed to receive a cable. 
     The roller element  2132  includes several openings, with the cable  2192  passing through each of the openings. The cable  2192  may include several integrated nodes, or connection points. For example, the cable  2192  includes a node  2195   a , a node  2195   b , a node  2195   c , a node  2195   d , and a node  2195   e . Each of the nodes may connect to a system(s) or body/bodies, thereby connecting the cable  2192  (and thus, the hinge assembly  2114 ) to the system(s)/body/bodies. 
     In some instances, a hinge assembly may, over several cycles, break down in certain areas due to wear. For example,  FIG.  44    illustrates an isometric view of an embodiment of a roller element  2232 , showing several grooves on an outer circumference of the roller element  2232 . As shown, the roller element  2232  includes a groove  2296   a  and a groove  2296   b  (both representative of additional grooves) on the outer circumference. The aforementioned grooves may result from relative movement, over the course of several instances, by one or more spacer elements (not shown in  FIG.  44   ) engaged with the roller element  2232  (see, for example,  FIGS.  33  and  34   ). As a result, the appearance of the roller element  2232  may change based on the grooves. The change in appearance may include a change in roughness/texture and/or reflectivity, as non-limiting examples. Generally, such changes from the original manufacturer specification are undesirable. 
       FIG.  45    illustrates an isometric view of an embodiment of a roller element  2332  with a coating  2397  on an outer circumference  2398  of the roller element  2332 , further showing a textured pattern applied to the coating  2397 . The coating  2397  may include polymers/plastics (as non-limiting examples) sprayed, molded, or otherwise applied to the outer circumference  2398 . Moreover, the coating  2397  may be manipulated to include a textured pattern that includes several grooves. For example, as shown in the enlarged view, the coating  2397  includes a groove  2396   a  and a groove  2396   b  (both representative of additional grooves) on the outer circumference  2398 . The grooves are “synthetic” grooves. In other words, the grooves are formed prior to assembly of the roller element  2132  with a hinge assembly (not shown in  FIG.  45   ). As a result, the roller element  2332  may be made to include an appearance of “wear” prior to any engagement with one or more spacer elements (not shown in  FIG.  45   ). In this manner, use of the roller element  2332  (i.e., use with a hinge assembly) results in little, if any change, in appearance. 
       FIG.  46    illustrates a cross sectional view of an embodiment of a roller element  2432 , showing the roller element  2432  defined by multiple materials. For example, the roller element  2432  may include a material  2499   a  and a material  2499   b . In some embodiments, the material  2499   a  includes a polymer/plastic, while the material  2499   b  includes a metal (such as steel or stainless steel, as non-limiting examples). In this manner, the weight of the roller element  2432  can be better controlled (as compared to use of a monolithic roller element), as polymers and metals are known to include different densities. Also, the appearance of the roller element  2432  can manipulated to, for example, match the appearance of another element of a hinge assembly (not shown in  FIG.  46   ). The roller element  2432  includes an opening  2454 . The opening  2454  can be defined by both the material  2499   a  and the material  2499   b , as shown in  FIG.  46   . In particular, the surface designed to receive a retention structure or a cable (not shown in  FIG.  46   ) is defined by the material  2499   b.    
       FIG.  47    illustrates a cross sectional view of an embodiment of a roller element  2532 , showing the roller element  2532  defined by multiple materials. For example, the roller element  2532  may include a material  2599   a  and a material  2599   b . In some embodiments, the material  2599   a  includes a polymer/plastic, while the material  2599   b  includes a metal (such as steel or stainless steel, as non-limiting examples). Also, the roller element  2532  includes an opening  2554  defined by both the material  2599   a  and the material  2599   b , as shown in  FIG.  47   . As shown in the enlarged view, the material  2599   b  is generally rough or jagged. This may result from cutting or other machining processes. When a retention structure or a cable (not shown in  FIG.  47   ) passes through the opening  2554 , the jagged surface of the material  2599   b  will not come into contact with, and cause damage to, the retention structure or cable, as the material  2599   a  covers the material  2599   b . Accordingly, a smoothing operation to the material  2599   b  need not be performed due to the relatively smooth surface of the material  2599   a , and the retention structure or cable is less susceptible to damage. 
     In order to adjust a hinge assembly (assemblies), some accessory devices herein may include additional features designed to adjust the tension provided to the retention structures that in turn alter features of the hinge assembly. For example,  FIG.  48    illustrates an isometric view of an embodiment of an accessory device  2600  with retention structures, showing each retention structure coupled to a tension adjustment system, in accordance with some described embodiments. Similar to other embodiments described herein, the accessory device  2600  may include a section  2602   a  coupled to a section  2602   b  by a hinge assembly  2614   a  that allows relative movement between the section  2602   a  and the section  2602   b . For purposes of illustration, one or more input mechanisms (such as a keyboard, touch pad, and/or touch input display) are removed from the section  2602   b . The section  2602   a  may include a segment  2604   a  coupled to a segment  2604   b  by a hinge assembly  2614   b  that allows relative movement between the segment  2604   a  and the segment  2604   b.    
     The accessory device  2600  further includes a retention structure  2616   a  and a retention structure  2616   b , both of which pass through the hinge assembly  2614   a  and the hinge assembly  2614   b . In some embodiments, at least one of the retention structure  2616   a  and the retention structure  2616   b  are integrated into the hinge assembly  2614   a  and the hinge assembly  2614   b  in an offset manner with respect to the center of the hinge assembly  2614   a  and the hinge assembly  2614   b . As a result, the retention structure  2616   a  and the retention structure  2616   b  may bias to the hinge assembly  2614   a  and the hinge assembly  2614   b , thereby causing a tendency in the hinge assembly  2614   a  and the hinge assembly  2614   b  to maneuver the accessory device  2600  to an open position or a closed position. For example, when the retention structure  2616   a  and the retention structure  2616   b  are offset to an outer/exterior region of the hinge assembly  2614   a  and the hinge assembly  2614   b , the hinge assembly  2614   a  and the hinge assembly  2614   b  may provide some bias to place the accessory device  2600  to the open position, as shown in  FIG.  48   . Generally, however, the biasing force does not automatically position the accessory device  2600  in the open position, and a user-applied force is required to position the accessory device  2600  in a desired manner. 
     While providing a biasing force can assist a user in opening the accessory device  2600 , the same biasing force may prevent the accessory device  2600  from remaining in a fully closed position when a user desires such a position. In this regard, the accessory device  2600  can integrate features designed to alter the tension to the retention structure  2616   a  and the retention structure  2616   b , thereby changing the forces provided by the hinge assembly  2614   a  and/or the hinge assembly  2614   b . For example, the accessory device  2600  may include a tension adjustment system  2668   a  and a tension adjustment system  2668   b  coupled to the retention structure  2616   a  and the retention structure  2616   b , respectively. The tension adjustment systems are designed to release, or at least relieve, some of the tension on the retention structures. As a result, when the accessory device  2600  in the closed position (as shown in  FIG.  2    for the accessory device  100 ), the retention structures do not cause the hinge assemblies to bias the accessory device  2600  in an undesired manner (i.e., the open position). However, when the accessory device  2600  transition to the open position, the tension adjustment system  2668   a  and the tension adjustment system  2668   a  allow the  2616   a  and the retention structure  2616   b , respectively, to return to prior tension profiles. This will be shown and described below. Also, although the tension adjustment system  2668   a  and the tension adjustment system  2668   a  are positioned in the section  2602   b , in some embodiments, the tension adjustment system  2668   a  and the tension adjustment system  2668   a  are positioned in the segment  2604   a  or the segment  2604   b . Also, while one end of the retention structure  2616   a  and the retention structure  2616   b  is coupled to the tension adjustment system  2668   a  and the tension adjustment system  2668   b , respectively, the opposing end of the retention structure  2616   a  and the retention structure  2616   b  can be fixed/fastened within the segment  2604   a.    
       FIG.  49    illustrates a plan view of an embodiment of a tension adjustment system  2768 , in accordance with some described embodiments. The tension adjustment system  2668   a  and the tension adjustment system  2668   b  (shown in  FIG.  48   ) may include any of the features describe herein for the tension adjustment system  2768 . The tension adjustment system  2768  may include a housing  2770  that carries the various components and features. For example, the tension adjustment system  2768  may include a biasing mechanism  2772  located in the housing  2770 . In some embodiments, the biasing mechanism  2772  is a spring. The tension adjustment system  2768  further includes a structural element  2774 , such as a bracket (as a non-limiting example). As shown in  FIG.  49   , the biasing mechanism  2772  is positioned in a manner such that the biasing mechanism  2772  biases the structural element  2774  away from a wall  2771  (of the housing  2770 ). The tension adjustment system  2768  further includes a fastening component  2776  that couples the structural element  2774  to a retention structure  2716  that passes through a hinge assembly (or assemblies) of an accessory device (not shown in  FIG.  49   ). The fastening component  2776  may include an adjustable component designed to provide an adjustment to the tension to the retention structure  2716  in order to “fine tune” the tension provided by the biasing mechanism  2772 . 
     The tension adjustment system  2768  further includes a coupling mechanism  2778   a  and a coupling mechanism  2778   b  coupled to an extension  2780   a  and an extension  2780   b , respectively, of the structural element  2774 . During use of an accessory device that integrates the tension adjustment system  2768 , the accessory device transitions from an open position to a closed position, or vice versa. During the transition, the tension applied to the retention structure  2716  may change, and the tension adjustment system  2768  compensates for the change using the biasing mechanism  2772 , the structural element  2774 , the coupling mechanism  2778   a , and the coupling mechanism  2778   b . An example will be further shown and discussed below. 
       FIG.  50    illustrates a plan view of the extension  2780   a  and the coupling mechanism  2778   a  of the tension adjustment system  2768  shown in  FIG.  49   , showing several features of the extension  2780   a  and the coupling mechanism  2778   a . The extension  2780   a , which is part of the structural element  2774 , is designed to mate with the coupling mechanism  2778   a . In this regard, the coupling mechanism  2778   a  may include a body  2779  and a coupling bracket  2781   a  connected to the body  2779  by a pivot  2783   a . The coupling mechanism  2778   a  may further include a coupling bracket  2781   b  connected to the body  2779  by a pivot  2783   b . The coupling bracket  2781   a  and the coupling bracket  2781   b  can rotate (as indicated by the dotted lines) relative to the body  2779  by way of the pivot  2783   a  and the pivot  2783   b , respectively. 
     In order to mate with the extension  2780   a , the coupling bracket  2781   a  and the coupling bracket  2781   b  may include one or more protrusions. For example, the coupling bracket  2781   a  may include a protrusion  2785   a , a protrusion  2785   b , and a protrusion  2785   c . The coupling bracket  2781   b  may include a protrusion  2785   d , a protrusion  2785   e , and a protrusion  2785   f . The extension  2780   a  may include a receptacle  2787   a , a receptacle  2787   b , and a receptacle  2787   c  designed to engage the protrusion  2785   a , the protrusion  2785   b , and the protrusion  2785   c , respectively. The extension  2780   a  may further include a receptacle  2787   d , a receptacle  2787   e , and a receptacle  2787   f  designed to engage the protrusion  2785   d , the protrusion  2785   e , and the protrusion  2785   f , respectively. 
     During a transition of an accessory device that integrates the tension adjustment system  2768 , the retention structure  2716  (shown in  FIG.  49   ) can move. This may include bending and/or stretching. In conjunction with the retention structure  2716 , the extension  2780   a  can move. Further, the extension  2780   a  can move relative to the coupling mechanism  2778   a . The movement of the extension  2780   a  may cause engagement or disengagement between at least some the receptacles of the extension  2780   a  and the protrusions of the coupling bracket  2781   a  and the coupling bracket  2781   b . This will be shown below. 
       FIGS.  51 - 54    illustrate an exemplary transition of an accessory device  2700  from an open position to a closed position, and resultant movement of the tension adjustment system  2768 .  FIG.  51    illustrates a side view of the accessory device  2700  in an open position, in accordance with some described embodiments. As shown, the accessory device  2700  includes a section  2702   a  coupled to a section  2702   b  by a hinge assembly  2714 . Further, the retention structure  2716  passes through the hinge assembly  2714  and connects to the tension adjustment system  2768 , which is located in the section  2702   b . Also, the retention structure  2716  may be offset (i.e., not centered) in the hinge assembly  2714 . For example, the retention structure  2716  is located along an outer, or exterior, region of the hinge assembly  2714 . As a result, the hinge assembly  2714  may provide some biasing force, based on the retention structure  2716  under tension, which assists the user in opening the accessory device  2700 . 
       FIG.  52    illustrates a plan view of the tension adjustment system  2768 , showing the position of the extension  2780   a  relative to the coupling mechanism  2778   a  when the accessory device  2700  is in the open position shown in  FIG.  51   . The coupling mechanism  2778   a  is designed to secure the extension  2780   a  in the open position of the accessory device  2700  (shown in  FIG.  51   ) in the manner described herein. For example, as shown in the enlarged view (with the coupling mechanism  2778   a  removed for simplicity and illustration), the protrusion  2785   a , the protrusion  2785   b , and the protrusion  2785   b  (of the coupling bracket  2781   a ) are positioned in the receptacle  2787   a , the receptacle  2787   b  and the receptacle  2787   c  (of the extension  2780   a ), respectively. Also, the protrusion  2785   d , the protrusion  2785   e , and the protrusion  2785   f  (of the coupling bracket  2781   b ) are positioned in the receptacle  2787   d , the receptacle  2787   e  and the receptacle  2787   f  (of the extension  2780   a ), respectively. Accordingly, the extension  2780   a  can be referred to as being fully engaged with the coupling mechanism  2778   a , as all protrusions are positioned in their respective receptacles. It should be noted that the coupling mechanism  2778   b  can secure the extension  2780   b  in a similar manner as described for the coupling mechanism  2778   a  and the extension  2780   a . The tension adjustment system  2768  can maintain the retention structure  2716  using the structural element  2774  and provide tension in the form of the biasing mechanism  2772 . Although not shown, the accessory device  2700  (shown in  FIG.  51   ) may include additional tension adjustment systems secured to additional retention structures, with each tension adjustment system working in a manner similar to that of the tension adjustment system  2768 . 
       FIG.  53    illustrates a side view of the accessory device  2700  in a closed position, subsequent to a transition from the open position, in accordance with some described embodiments. As shown, the section  2702   a  is rotated, using the hinge assembly  2714 , such that the section  2702   a  is positioned over the section  2702   b . When the retention structure  2716  is offset within the hinge assembly  2714 , the retention structure  2716  may provide additional torque on the components of the hinge assembly  2714  and subsequently provide at least some force to the hinge assembly  2714  that biases the accessory device  2700  in the direction of the open position (shown in  FIG.  51   ). Generally, in the closed position, the section  2702   a  lies flat, and is parallel with respect to the section  2702   b . Subject to the biasing force, the accessory device  2700  may tilt or may not lie flat, and accordingly, may parallel with respect to the section  2702   b . However, the tension adjustment system  2768  can reduce the tension on the retention structure  2716 , thereby remove the biasing force provided by the hinge assembly  2714  so that the aforementioned sections are parallel to each other in the closed position. 
       FIG.  54    illustrates a plan view of the tension adjustment system, showing the position of the extension  2780   a  relative to the coupling mechanism  2778   a  when the accessory device  2700  is in the closed position shown in  FIG.  53   . Due to the transition of the accessory device  2700  to the closed position, a pulling force may be exerted on the retention structure  2716 , thereby increasing the tension on the retention structure  2716 . The increased tension to the retention structure  2716  may provide a force that causes the structural element  2774  to move, which in turn causes a change in the relative position between the extension  2780   a  and the coupling mechanism  2778   a . As shown in the enlarged view (with the coupling mechanism  2778   a  removed for simplicity and illustration), the protrusions of the coupling mechanism  2778   a  are shifted with relative to their respective receptacles of the extension  2780   a . For example, the protrusion  2785   a , the protrusion  2785   b , and the protrusion  2785   c  (of the coupling bracket  2781   a ) are shifted (and located at different positions on) the receptacle  2787   a , the receptacle  2787   a , and the receptacle  2787   c , respectively. Also, the protrusion  2785   d , the protrusion  2785   e  and the protrusion  2785   f  (of the coupling bracket  2781   b ) are shifted (and located at different positions on) the receptacle  2787   d , receptacle  2787   e , and the receptacle  2787   f , respectively. Accordingly, the extension  2780   a  is partially engaged with the coupling mechanism  2778   a , as the extension  2780   a  is partially pulled away from the coupling mechanism  2778   a . Although not expressly shown, the extension  2780   b  may be in similar relationship with respect to the coupling mechanism  2778   b.    
     It should be noted that the retention structure  2716 , under increased tension due to the transition to the closed position, is pulled in a direction  2790 , and the structural element  2774 , along with the extension  2780   a  and the extension  2780   b , is also pulled in the direction  2790 . Based on the structural element  2774  moving in the direction  2790  (due to the partial decoupling between the extensions and the coupling mechanism), the structural element  2774  provides at least some tension relief to the retention structure  2716 . As a result, the torque provided by the retention structure  2716  to the hinge assembly  2714  (shown in  FIG.  53   ) is reduced such that the bias to the open position is reduced or eliminated, and the accessory device  2700  remains fully closed. Accordingly, the tension adjustment system  2768  provides a notable advantage over stationary fasteners that fixed each end of the retention structure  2716  to the accessory device  2700 , and subsequently provide a relatively static tension to the retention structure  2716 . 
       FIGS.  55  and  56    illustrate alternate embodiments of accessory devices. The accessory devices shown and described in  FIGS.  55  and  56    may integrate at least some features previously described for an accessory device, such as hinge assemblies and/or retention structures. 
       FIG.  55    illustrates an isometric view of an alternate embodiment of an accessory device  2800 , showing an alternate arrangement of retention structures passing through multiple hinge assemblies, in accordance with some described embodiments. As shown, the accessory device  2800  includes a section  2802   a  and a section  2802   b  connected to the section  2802   a  by a hinge assembly  2814   a , thereby allowing relative rotational movement between the section  2802   a  and the section  2802   b . The section  2802   a  further includes a segment  2804   a  and a segment  2804   b  connected to the segment  2804   a  by a hinge assembly  2814   b , thereby allowing relative rotational movement between the segment  2804   a  and the segment  2804   b.    
     The section  2802   b  includes an input mechanism  2808 . As shown in  FIG.  53   , the input mechanism  2808  is a display, which includes a capacitive touch input display. The input mechanism  2808  is presenting a keyboard. However, the input mechanism  2808  may present several different types of input features, such as a dynamic row of function buttons that displays information specific to a software application running on an electronic device (not shown in  FIG.  55   ), a touch pad (in conjunction with the keyboard), and/or other features. It should be noted that the input mechanism  2808  can provide a command to an electronic device (not shown in  FIG.  55   ) that is in communication with the accessory device  2800 . 
     The accessory device  2800  further includes a retention structure  2816   a , a retention structure  2816   b , and a retention structure  2816   c . As shown, the retention structure  2816   a , the retention structure  2816   b , and the retention structure  2816   c  pass through both the hinge assembly  2814   a  and the hinge assembly  2814   b . With at least one of the retention structures passing through both the hinge assembly  2814   a  and the hinge assembly  2814   b , the accessory device  2800  can provide coordinated and regulated movement of the hinge assembly  2814   a  and/or the hinge assembly  2814   b . For instance, similar to the hinge assembly  114   a  and the hinge assembly  114   b  shown and described in  FIGS.  6  and  7   , the hinge assembly  2814   a  may be free to move while the hinge assembly  2814   b  remains fixed, and vice versa. 
       FIG.  56    illustrates an isometric view of an alternate embodiment of an accessory device  2900 , showing a different number of retention structures passing through hinge assemblies, in accordance with some described embodiments. As shown, the accessory device  2900  includes a section  2902   a  and a section  2902   b  connected to the section  2902   a  by a hinge assembly  2914   a , thereby allowing relative rotational movement between the section  2902   a  and the section  2902   b . The section  2902   a  further includes a segment  2904   a  and a segment  2904   b  connected to the segment  2904   a  by a hinge assembly  2914   b , thereby allowing relative rotational movement between the segment  2904   a  and the segment  2904   b.    
     The accessory device  2900  further includes a retention structure  2916   a , a retention structure  2916   b , a retention structure  2916   c , a retention structure  2916   d , and a retention structure  2916   e . As shown, the retention structure  2916   a , the retention structure  2916   c , and the retention structure  2916   e  pass through both the hinge assembly  2914   a , while the retention structure  2916   b  and the retention structure  2916   d  pass through the hinge assembly  2914   b . By providing a different number of retention structures that pass through the hinge assemblies, the hinge assemblies may provide different properties. For example, due to the greater number of integrated retention structures, the hinge assembly  2914   a  may provide greater stiffness than the hinge assembly  2914   b . As a result, the hinge assembly  2914   a  can support more weight/force than the hinge assembly  2914   b , or the hinge assembly  2914   a  may resist move more than the hinge assembly  2914   b . However, the hinge assembly  2914   b  may be more flexible than the hinge assembly  2914   a , thereby providing the hinge assembly  2914   b  with greater ease of movement. It should be noted that in some embodiments (not shown in  FIG.  56   ), the hinge assembly  2914   b  includes a greater number of retention structures as compared to the hinge assembly  2914   a.    
       FIGS.  57  and  58    illustrate an accessory device capable of automated opening and closing using a retention structure.  FIG.  57    illustrates a side view of an alternate embodiment of an accessory device  3000  with an automated opening system, showing the accessory device  3000  in a closed position, in accordance with some described embodiments. As shown, the accessory device  3000  includes a section  3002   a  and a section  3002   b  connected to the section  3002   a  by a hinge assembly  3014   a , thereby allowing relative rotational movement between the section  3002   a  and the section  3002   b . The section  3002   a  further includes a segment  3004   a  and a segment  3004   b  connected to the segment  3004   a  by a hinge assembly  3014   b , thereby allowing relative rotational movement between the segment  3004   a  and the segment  3004   b . Also, similar to prior embodiments, the accessory device  3000  is capable of carrying an electronic device  3080 . 
     The accessory device  3000  may further include a retention structure  3016  that passes through both the hinge assembly  3014   a  and the hinge assembly  3014   b . The retention structure  3016  may promote synchronous movement of the hinge assembly  3014   a  and the hinge assembly  3014   b . The accessory device  3000  may additional features designed to further promote movement of the hinge assemblies. For example, the accessory device  3000  may include automated opening. The automated opening may include an automated system  3062   a  and an automated system  3062   b . The automated system  3062   a  and the automated system  3062   b  may each include a motor (including a step motor), a spring-loaded mechanism, and/or a cam mechanism. The accessory device  3000  may include an internal power supply (not shown in  FIG.  57   ), such as a battery, that provides energy to the automated system  3062   a  and the automated system  3062   b . Alternatively, the accessory device  3000  can receive energy from an internal power supply located in an electronic device (not shown in  FIG.  57   ) when the accessory device  3000  is coupled to the electronic device. As shown, the automated system  3062   a  is secured to one end of the retention structure  3016 , and the automated system  3062   b  is secured to the other (opposing) end of the retention structure  3016 . The automated system  3062   a  and the automated system  3062   b  can work in unison to adjust the tension of the retention structure  3016 . For instance, the automated system  3062   a  and the automated system  3062   b  can provide a pulling force to each end the retention structure  3016 . The pulling force may include a winding of the retention structure  3016  to reduce the amount of “free” or available retention structure available to the hinge assembly  3014   a  and the hinge assembly  3014   b . As result of the pulling force to the retention structure  3016 , the retention structure  3016  may cause movement of the hinge assembly  3014   a  and the hinge assembly  3014   b . This will be further shown and described below. The accessory device  3000  may further include a button  3064  that can be operated by a user. The button  3064  may include a mechanical button that actuates a switch (not shown in  FIG.  57   ), or a button with a capacitive touch interface. The button  3064  is used to control the automated system  3062   a  and the automated system  3062   b . Accordingly, the button  3064  can control the retention structure  3016 , and in turn, control the hinge assembly  3014   a  and the hinge assembly  3014   b . It should be noted that in some embodiments, the accessory device  3000  includes a single automated system. 
       FIG.  58    illustrates a side view of the accessory device shown in  FIG.  57   , showing the accessory device  3000  in an open position using the automated opening system. When a user (not shown in  FIGS.  57  and  58   ) contacts the button  3064 , the accessory device  3000  can automatically transition from the closed position (shown in  FIG.  57   ) to the open position shown in  FIG.  58   . By contacting the button  3064 , the user activates the automated system  3062   a  and the automated system  3062   b , which increases the tension in the retention structure  3016  and causes movement of the hinge assembly  3014   a  and the hinge assembly  3014   b . The movement of the hinge assembly  3014   a  rotates the section  3002   a  from the section  3002   b . Also, the movement of the hinge assembly  3014   b  causes the segment  3004   a  to move relative to the segment  3004   b . As a result, the electronic device  3080  is positioned at a desirable angle with respect to an input mechanism  3008  of the section  3002   b . Although not shown, the accessory device  3000  may be capable of transitioning back to the closed position (shown in  FIG.  57   ) by subsequently contacting the button  3064  and/or by contacting the input mechanism  3008 .  FIGS.  57  and  58    illustrate an accessory device that can automatically move to vary desirable positions without manual movement (other than interacting with the button  3064  or the input mechanism  3008 ). 
     Hinge assemblies described herein may be integrated with other devices. For example,  FIG.  59    illustrates an isometric view of an embodiment of a portable electronic device  3101 , showing the portable electronic device  3101  in an open position, in accordance with some described embodiments. The portable electronic device  3101  may include a laptop computing device. As shown, the portable electronic device  3101  includes a housing  3103   a , or display housing, that carries a display  3105  of the portable electronic device  3101 . The portable electronic device  3101  may further include a housing  3103   b , or base portion, that includes an input mechanism such as a keyboard assembly  3107  and a touch pad  3109 , both of which are designed to generate an input or command to a processing system (not shown in  FIG.  59   ) of the portable electronic device  3101 . The portable electronic device  3101  may further include a hinge assembly  3114  coupled to the housing  3103   a  and the housing  3103   b . The hinge assembly  3114  allows for rotational movement of the housing  3103   a  with respect to the housing  3103   b , and vice versa. The portable electronic device  3101  is shown in an open position. However, the hinge assembly  3114  allows the housing  3103   a  to rotate over the housing  3103   b  such that the display  3105  is positioned over the keyboard assembly  3107  and the touch pad  3109 , thereby defining a closed position. The hinge assembly  3114  may include one or more features described herein for hinge assemblies, spacer elements, roller elements, and/or retention structures, as non-limiting examples. Also, the portable electronic device  3101  may include an audio module  3118 , or speaker, that emits acoustical energy in the form of audible sound. Based on the position of the portable electronic device  3101  and the hinge assembly  3114 , the acoustical energy produced by the audio module  3118  can exit the housing  3103   b , and reflect off of the hinge assembly  3114  in a direction toward a user. 
       FIG.  60    illustrates a side view of the portable electronic device  3101  shown in  FIG.  59   , showing the portable electronic device  3101  in a closed position. As shown, the housing  3103   a  includes a thickness  3121  and the housing  3103   b  includes a thickness  3123  that is greater than the thickness  3121  of the housing  3103   a . Also, the thickness  3121  of the housing  3103   a  is the same, or at least approximately the same, thickness as that of the hinge assembly  3114 . Also, the housing  3103   b  may include a notch  3115 , or curved portion, that allows a user to position a digit (such as a finger) under the housing  3103   a  and pull the housing  3103   a  away from the housing  3103   b , and transition the portable electronic device  3101  from the closed position to the open position (as shown in  FIG.  59   ). 
     The housing  3103   b  may include a recess. As shown in  FIG.  60   , the recess may position the keyboard assembly  3107  and the touch pad  3109  sub-flush, or below, an uppermost surface of the housing  3103   b . In this manner, in the closed position, the display  3105  may not contact the keyboard assembly  3107  or the touch pad  3109 . Also, in the closed position, the portable electronic device  3101  defines an opening  3117  capable of carrying an object (not shown in  FIG.  60   ) such as a stylus or other digital interactive tool designed to provide an input to the display  3105 . In this manner, when the display  3105  includes touch input capabilities, the portable electronic device  3101  can carry the object and the object can be removed from the opening  3117  so that the user can interact with the display  3105  using the object. As shown, the hinge assembly  3114  and the housing  3103   b  are shaped such that the opening  3117  includes a circular opening. However, other shapes are possible. 
     Furthermore, the opening  3117  may provide a thermal dissipation path for the portable electronic device  3101 . For example, the portable electronic device  3101  may include an opening  3119   a  (representative of several openings) used as an air intake opening to provide cooling capabilities for internal components (such as processing circuits) located in the housing  3103   b . The air entering the opening  3119   a  can subsequently leave an opening  3119   b  (representative of several openings) after the air convectively cools the internal components. 
       FIG.  61    illustrates an isometric view of an alternate embodiment of a portable electronic device  3201 , showing the portable electronic device  3201  in an open position, in accordance with some described embodiments. The portable electronic device  3201  may include a laptop computing device. As shown, the portable electronic device  3201  may include a housing  3203   a , or display housing, that carries a display  3205  of the portable electronic device  3201 . The portable electronic device  3201  may further include a housing  3203   b , or base portion, that includes input mechanism such as a keyboard assembly  3207  and a touch pad  3209 , both of which are designed to generate an input or command to a processing system (not shown in  FIG.  61   ) of the portable electronic device  3201 . The portable electronic device  3201  may further include a hinge assembly  3214  coupled to the housing  3203   a  and the housing  3203   b . The hinge assembly  3214  allows for rotational movement of the housing  3203   a  with respect to the housing  3203   b , and vice versa. The portable electronic device  3201  is shown in an open position. However, the hinge assembly  3214  allows the housing  3203   a  to rotate over the housing  3203   b  such that the display  3205  is positioned over the keyboard assembly  3207  and the touch pad  3209 , thereby defining a closed position. The hinge assembly  3214  may include one or more features described herein for hinge assemblies, spacer elements, roller elements, and/or retention structures, as non-limiting examples. 
     While the housing  3203   b  provides an additional thickness (as compared to the housing  3203   a ), the housing  3203   b  may further provide a two-tiered thickness. For instances, the housing  3203   b  includes a dimension  3225   a  and a dimension  3225   b . As shown, the dimension  3225   b  is greater than the dimension  3225   a , corresponding to a greater thickness along the dimension  3225   b  as compared to the thickness along the dimension  3225   a . As a result, the housing  3203   b  that can be utilized by positioning certain components in a location of the housing  3203   b  corresponding to the dimension  3225   b . For example, the housing  3203   b  includes a port  3227  that can be used for power and data transmission to the portable electronic device  3201 . The housing  3203   b  may further include an audio module  3229  that can be used for transmission of acoustical energy in the form of audible sound. As shown, both the port  3227  and the audio module  3229  are in a location of the housing  3203   b  corresponding to the dimension  3225   b.    
       FIG.  62    illustrates a side view of the portable electronic device  3201  shown in  FIG.  61   , showing the accessory device in a closed position. As shown, the hinge assembly  3214  allows the housing  3203   a  to move relative to the housing  3203   b . The hinge assembly  3214  may include a retention structure  3216  used to keep roller elements and spacer elements (not labeled) together, and to promote frictional engagement between the roller elements and the spacer elements. 
       FIG.  63    illustrates a block diagram of an electronic device  3300 , in accordance with some embodiments. The electronic device  3300  may include a portable electronic device, such as a mobile wireless communication device described herein. The electronic device  3300  is capable of implementing the various techniques described herein. The electronic device  3300  may include one or more processors  3310  for executing functions of the electronic device  3300 . The one or more processors  3310  can refer to at least one of a central processing unit (CPU) and at least one microcontroller for performing dedicated functions. Also, the one or more processors  3310  can refer to application specific integrated circuits. 
     According to some embodiments, the electronic device  3300  can include a display unit  3320 . The display unit  3320  is capable of presenting a user interface that includes icons (representing software applications), textual images, and/or motion images. In some examples, each icon can be associated with a respective function that can be executed by the one or more processors  3310 . In some cases, the display unit  3320  includes a display layer (not illustrated), which can include a liquid-crystal display (LCD), light-emitting diode display (LED), or the like. According to some embodiments, the display unit  3320  includes a touch input detection component and/or a force detection component that can be configured to detect changes in an electrical parameter (e.g., electrical capacitance value) when the user&#39;s appendage (acting as a capacitor) comes into proximity with the display unit  3320  (or in contact with a transparent cover layer that covers the display unit  3320 ). The display unit  3320  is connected to the one or more processors  3310  via one or more connection cables  3322 . 
     According to some embodiments, the electronic device  3300  can include one or more sensors  3330  capable of detecting an orientation of the electronic device  3300 . In some examples, the one or more sensors  3330  may include an accelerometer, an electronic gyroscope, or some other orientation sensor. In some embodiments, the one or more sensors  3330  can determine whether the electronic device  3300  is positioned in a manner that a user can use certain features, such as an input mechanism of an accessory device (not shown in  FIG.  63   ). In response, the one or more processors  3310  can modify a notification that activates both the keyboard and the display unit  3320 . The one or more sensors  3330  can also include magnetic field sensors, such as Hall Effect sensors. The one or more sensors  3330  is/are connected to the one or more processors  3310  via one or more connection cables  3332 . 
     According to some embodiments, the electronic device  3300  can include one or more input/output components  3340  that enable communication between a user and the electronic device  3300 . In some cases, the one or more input/output components  3340  can refer to a button or a switch that is capable of actuation by the user. In some examples, the one or more input/output components  3340  can refer to a switch having a mechanical actuator (e.g., spring-based switch, slide-switch, rocker switch, rotating dial, etc.) or other moving parts that enable the switch to be actuated by the user. The one or more input/output components  3340  can include an accelerometer that determines whether the electronic device  3300 , and to what extent, is accelerating or decelerating. When the one or more input/output components  3340  are used, the one or more input/output components  3340  can generate an electrical signal that is provided to the one or more processors  3310  via one or more connection cables  3342 . 
     According to some embodiments, the electronic device  3300  can include a power supply  3350  that is capable of providing energy to the operational components of the electronic device  3300 . In some examples, the power supply  3350  can refer to a rechargeable battery. The power supply  3350  can be connected to the one or more processors  3310  via one or more connection cables  3352 . The power supply  3350  can be directly connected to other devices of the electronic device  3300 , such as the one or more input/output components  3340 . In some examples, the electronic device  3300  can receive power from another power sources (e.g., an external charging device) not shown in  FIG.  63   . 
     According to some embodiments, the electronic device  3300  can include memory  3360 , which can include a single disk or multiple disks (e.g., hard drives), and includes a storage management module that manages one or more partitions within the memory  3360 . In some cases, the memory  3360  can include flash memory, semiconductor (solid state) memory or the like. The memory  3360  can also include a Random Access Memory (“RAM”) and a Read-Only Memory (“ROM”). The ROM can store programs, utilities or processes to be executed in a non-volatile manner. The RAM can provide volatile data storage, and stores instructions related to the operation of the electronic device  3300 . In some embodiments, the memory  3360  refers to a non-transitory computer readable medium, where an operating system (“OS”) is established at the memory  3360  that can be configured to execute software applications. The one or more processors  3310  can also be used to execute software applications. In some embodiments, a data bus  3362  can facilitate data transfer between the memory  3360  and the one or more processors  3310 . 
     According to some embodiments, the electronic device  3300  can include wireless communications components  3370 . A network/bus interface  3372  can couple the wireless communications components  3370  to the one or more processors  3310 . The wireless communications components  3370  can communicate with other electronic devices via any number of wireless communication protocols, including at least one of a global network (e.g., the Internet), a wide area network, a local area network, a wireless personal area network (WPAN), or the like. In some examples, the wireless communications components  3370 . 
     It should also be noted that accessory described herein may include several features described herein for the electronic device  3300 , such as one or more processors  3310 , the sensors  3330 , the input/output components  3340 , the power supply  3350 , memory  3360 , and the wireless communications components  3370 . 
     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: 20200317
Publication Date: 20230131
Grant Date: 20230131
Priority Date: 20190318
Inventors: MILLER, ARI P.
ROBINSON, KEVIN M.
CHEN, CHIEN-TSUN
Assignee: APPLE INC
CPC Classifications: [{"code": "E05Y2600/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "E05D11/082", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D11/1028", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05Y2900/606", "inventive": false, "first": false, "tree": "[]"}, {"code": "E05Y2201/62", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16C11/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": true, "tree": "[]"}, {"code": "E05D11/1028", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16C11/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05Y2600/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1662", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D11/082", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05Y2201/62", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1669", "inventive": true, "first": false, "tree": "[]"}, {"code": "E05D11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": true, "tree": "[]"}, {"code": "E05Y2999/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "E05Y2999/00", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 72514300