Patent Publication Number: US-2022236765-A1

Title: Accessories for portable electronic devices

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 16/879,341, entitled “ACCESSORIES FOR PORTABLE ELECTRONIC DEVICES,” filed May 20, 2020, set to issue Apr. 19, 2022 as U.S. Pat. No. 11,307,615, which is a continuation of U.S. application Ser. No. 16/053,774, filed Aug. 2, 2018, entitled “ACCESSORIES FOR PORTABLE ELECTRONIC DEVICES,” issued on May 26, 2020 as U.S. Pat. No. 10,664,012, which claims the benefit of U.S. Provisional Application No. 62/541,537, entitled “ACCESSORIES FOR PORTABLE ELECTRONIC DEVICES,” filed Aug. 4, 2017, the contents of all of which are incorporated by reference herein in their entirety for all purposes. 
    
    
     FIELD 
     Embodiments described herein generally relate to accessory devices that can be removably coupled with portable electronic devices. More specifically, the described accessory devices can be multi-segment articles that can support portable electronic devices at different inclination angles. 
     BACKGROUND 
     Recent advances in computing devices have made portable electronic devices increasingly more prevalent. Users often pair different accessories with their electronic devices to add features and/or to customize their electronic devices. Besides adding functionalities to the electronic devices, accessories can be protective in nature or simply aesthetically pleasing adornments, or in some cases be both protective and ornamental in nature. For example, accessories can be articles such as cases and/or folios. In some cases, while portable electronic devices are often equipped with touch screens, accessories can include input devices such as keyboards to provide additional input options to the users as well as to offer protection to the electronic devices. 
     SUMMARY 
     In one aspect, a folio for use with a portable electronic device having a display assembly overlaid by a protective layer is described. The folio may include a base segment having a size and shape in accordance with the portable electronic device. The folio may further include an attachment segment coupled to the base segment, the attachment segment comprising a mechanism capable of securing a rear surface of the portable electronic device to the attachment segment. In some instances, when the portable electronic device is secured to the attachment segment, i) a closed configuration comprises the base segment overlaying the protective layer, and the attachment segment overlaying the rear surface of the portable electronic device; and (ii) a support configuration comprises both the portable electronic device and the attachment segment above the base segment, and the attachment segment balances and supports the portable electronic device. 
     In another aspect, a folio for use with a portable electronic device is described. The folio may include a base carrying an input device capable of communicating with the portable electronic device. The folio may further include an attachment panel capable of removably coupling with the portable electronic device. The folio may further include a cascading rotational support system having a first rotation element coupled to the base and a second rotation element coupled to the attachment panel such that the cascading rotational support system is capable of suspending the portable electronic device above the base. In some instances, when a first torque is applied to the attachment panel, only the first rotation element rotates until the first rotation element reaches a first hard stop. Further, in some instances, when a second torque opposite the first torque is applied to the attachment panel, only the second rotation element rotates until the second rotation element reaches a second hard stop different from the first hard stop. 
     In another aspect, folio for removably coupling to a portable electronic device is described. The folio may include a folio removably coupled to the portable electronic device. The folio may include a first segment carrying an input device that is capable of communication with the portable electronic device. The folio may further include a second segment pivotally coupled to the first segment. The folio may further include a third segment pivotally coupled to the second segment. The third segment is capable of being removably coupled to the rear surface of the portable electronic device. In some instances, in a support configuration, the folio supports the portable electronic device, the second segment is at an acute angle with respect to the first segment and the portable electronic device and the third segment are suspended above the first segment. Also, in some instances, in a closed configuration, the first segment covers an entirety of the display assembly. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       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 electronic system that can include an accessory article and a portable electronic device, in accordance with some embodiments. 
         FIG. 2A  illustrates a side view of the electronic system shown in  FIG. 1 , showing the system a closed configuration. 
         FIG. 2B  illustrates an isometric view of the electronic system shown in  FIG. 2A , further showing a digital pen. 
         FIG. 3  illustrates a side view of a support configuration of the article carrying the electronic device. 
         FIG. 4A-4C  illustrate a transition of the electronic system from a closed configuration to a support configuration. 
         FIG. 5  illustrates an isometric view of the electronic system shown in  FIG. 1 , showing the electronic device separated from the article along with a digital pen. 
         FIGS. 6A and 6B  illustrate two side views of an electronic system in different configurations, in accordance with some embodiments. 
         FIG. 7A-7D  illustrate a transition of the electronic system, shown in  FIGS. 6A and 6B , transitioning from a closed configuration to a clipboard configuration. 
         FIG. 8  illustrates a block diagram of a method for automatically altering an operation state of a portable electronic device based on the configuration of an article removably coupled to the portable electronic device, in accordance with some embodiments. 
         FIG. 9  shows a block diagram depicting a method for automatically altering operation of a portable electronic device based on different types of input devices in communication with the portable electronic device, in accordance with some embodiments. 
         FIG. 10  illustrates a block diagram of a computing device in accordance with some 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 can be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     DETAILED DESCRIPTION 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments 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; other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     Accessory devices such as cases and covers can often be coupled with portable electronic devices to provide added benefits to the portable electronic devices such as in the form of protection and improved appearance. While portable electronic devices are often handheld by the users, the portable electronic devices can also be placed on surfaces such as tables in situations such as when users watch videos with the portable electronic devices or when users connect external input devices such as accessory keyboards to the portable electronic devices and use the portable electronic devices primarily as displays. In those situations when portable electronic devices are placed on surfaces, it is often desirable to have a portable electronic device inclined relative to the surface to provide better viewing angles for the users. 
     Some accessory devices can be arranged in certain configurations to support the rear surface of the portable electronic device so that users do not need to manually hold the portable electronic device at inclination angles (corresponding to the viewing angles). However, designing an accessory device as a stand for a portable electronic device can be challenging. Because of its internal components and display assembly, the portable electronic device can often be heavier than the accessory device. As such, it can often be difficult to balance the portable electronic device by the accessory device because the lighter (and sometimes also smaller) accessory device is required to support the heavier portable electronic device. Conventional accessory devices are often designed with configurations that sacrifice flexibilities in order to provide balance to the systems. For example, conventional accessory devices may only allow a single or a very limited number of possible inclination angles of the portable electronic device so that the selectable view angles are limited and often fixed. 
     Embodiments described herein relate to accessory articles that can support portable electronic devices (tablet computers, mobile phones, etc.) at inclination angles and at the same time can allow the inclination angles to be finely adjusted. Some exemplary accessory articles described herein can take the form of a multi-segmented folio that can, in a closed configuration, cover both the front and rear surfaces of a portable electronic device. The article can be re-arranged into a configuration of a stand (sometimes referred to as a “support configuration”) that can be brought behind the portable electronic device to support the portable electronic device at an inclination angle. 
     In terms of the structure, in some instances, an exemplary accessory article can include a first segment that can carry an input device such as a keyboard that can be controlled by a user to input commands to the portable electronic device. The accessory article can also include a second segment that can be coupled to the first segment via a first hinge assembly. The accessory article can further include a third segment that can carry attachment components for removably attaching the portable electronic device to the third segment. The third segment can be coupled to the second segment via a second hinge assembly. In this regard, the second segment can be positioned between the first and third segments. In a closed configuration, the first segment can cover a first surface of the portable electronic device while the second and third segments can cooperate to cover a second surface of the portable electronic device opposite the first surface. In a support configuration, the first segment can become a base of the entire system (i.e. the system having the accessory article and the portable electronic device). The second segment can be inclined inward and at an acute angle relative to the first segment. The third segment can be suspended above the first segment and be inclined outward. 
     In this support configuration, the input device, such as a keyboard, can positioned be on the base of the system. At the same time, the portable electronic device, which can be carried by the third segment, can be suspended above and inclined with respect to the input device. Hence, the system in this configuration can be similar to a laptop computer. In addition, the second hinge assembly that controls the orientation of the third segment can be finely adjusted to change the viewing angle of the portable electronic device. Also, because of the presence of the second segment that inclines towards the first segment, the center of gravity of this system can shift more towards the middle of the system, thus creating an equilibrium state. An equilibrium state of the system can refer to a balanced and static state in which the components of the system, without any external support or any external force, remain stationary relative to each other. 
     Exemplary accessory articles in accordance with some embodiments can include various mechanical features that further facilitate the balance in the support configuration. For example, the hinge assemblies of the accessory articles can have one or more hard stops. A hard stop can be associated with a maximum or minimum angle that a hinge assembly can rotate turn. At a hard stop, a rotatable part of the hinge assembly may encounter a stationary part (such as pressing against a wall) so that no further movement is allowed. The first hinge assembly, which connects the first and second segments, may include a hard stop at an acute angle. This hard stop can ensure that the second segment is limited to a position defining an acute angle relative to the first segment so that, in any support configurations, the second segment can always shift weight of the system inwards towards the middle of the system. The second hinge assembly, which connects the third segment carrying the portable electronic device, can also have one or more hard stops that limit the range of the inclination angle of the portable electronic device. For example, the second hinge assembly can have a hard stop that prevents the portable electronic device from turning to an orientation that is parallel relative to the first segment. It should be noted, however, the inclination angle can be finely adjusted within a range of angles. 
     To further support an equilibrium state of a support configuration, the hinge assemblies can also have stiffness that can withstand the weight of the portable electronic device. The stiffness of a hinge assembly can be associated with the torque friction of the hinge assembly. The torque friction of a hinge assembly can be the minimum torque required to overcome the friction of the hinge assembly to rotate the hinge assembly. A hinge assembly can have one or more torque components such as a friction clip that generate torque in favor of or against movement. For a support configuration, each hinge assembly of the accessory article needs to withstand the weight of a load, which can be a combination of the weights of one or more segments and/or the portable electronic device. The load can exert a torque that is roughly equal to a perpendicular component of the weight of the load multiplied by the distance between the center of gravity of the load and the hinge assembly. To maintain a support configuration in an equilibrium state, each hinge assembly can have a torque friction that can be larger than the expected maximum torque exerted by a load. In other words, each hinge assembly can be sufficiently stiff to withstand the weight of the system or part of the system so that the hinge assembly will not turn unless an external force (such as an applied force by a user) is exerted to the system. 
     The hinge assemblies in some exemplary accessory articles can also cooperate to form a cascading rotational support system. A cascading rotational support system can refer to two or more rotational supports that are related or connected to each other based on certain qualities and/or turn orders. For example, the hinge assemblies can have asymmetrical torque frictions (i.e. having different torque frictions in different rotational directions) that are related to other hinge assemblies. For the ease of reference, the turn direction from the closed configuration to the support configuration may be referred to as a first direction. The opposite turn direction from the support configuration to the closed configuration may be referred to as the second direction. In some configurations, the first hinge assembly can have a torque friction that is less than that of the second hinge assembly in the first direction. However, in some configurations, the first hinge assembly can have a torque friction that is greater than that of the second hinge assembly in the second direction. This arrangement can allow a particular turn order between the first and second hinge assemblies. When the accessory article is turned from the closed configuration to the support configuration, the first hinge assembly, being easier to rotate due to its relatively lower torque friction, can rotate first (before the second hinge assembly rotates) until the first hinge assembly reaches the aforementioned hard stop. After the first hinge assembly reaches the hard stop, the second hinge assembly can subsequently rotate back and forth to finely adjust the inclination angle of the portable electronic device without moving the first hinge assembly. This is due in part to the first hinge assembly reaching a hard stop in the first direction and also the first hinge assembly being having a relatively higher torque friction than the second hinge assembly in the second direction. This arrangement of asymmetrical torque frictions can facilitate a convenient adjustment of the viewing angle of the portable electronic device because the first hinge assembly can remain stationary when the viewing angle (which is largely associated with the second hinge assembly) is adjusted. 
     Accessory articles in accordance with some embodiments described herein can also include other mechanical or electronic features that provide additional benefits to the portable electronic devices. As non-limiting examples, first, a hinge assembly of an accessory article can have an elongated hollow body that can serve as a retainer to receive a digital pen such as a stylus or another interactive tool that can be used with the portable electronic device. Second, a segment of some exemplary accessory articles can be less stiff than other segments and can include two structural layers sandwiching a viscoelastic material that promotes a dampening of the vibration of the system. Third, an exemplary accessory article can include a relatively large segment (as compared to other smaller segments) that can have a size and shape generally in accordance with the portable electronic device. Some of the smaller segments can be connected to one or more hinge assemblies that allow the smaller segments to be folded on top of each other. In some configurations, the body of the portable electronic device can largely overlay the relatively large segment and the stacked smaller segments can be position at one end of the portable electronic device to make the device slightly inclined. Hence, this configuration can allow the accessory article to serve like a clipboard for the portable electronic device. Fourth, an exemplary accessory article can include battery packs that can store and transfer power to the portable electronic device. Fifth, an exemplary accessory article can include external connection ports (e.g. Universal Serial Bus, or “USB”) that allow wired transfer of information and power between the portable electronic device and an external device via the accessory article. 
     These and other embodiments are discussed below with reference to  FIGS. 1-10 . 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 electronic system that can include an article  100  and an electronic device  102 , in accordance with some embodiments. It should be noted that the article  100  may sometimes be referred to as an accessory, an accessory unit, an accessory device, accessory segment, folio, stand, support etc. As shown, the article  100  is coupled with the electronic device  102 . However, the coupling may include a removable coupling such that the electronic device  102  may be removed, or separated from, the article  100  without damaging the article  100  and the electronic device  102 . Also, the article  100  may include a multi-segmented article. The segments in article  100  could sometimes be referred to panels. As it will be discussed in further detail below, the article  100  can be arranged and re-arranged into different configurations for different purposes. In one case, the article  100  can define both a support configuration (also referred to as a first configuration) as well as a closed configuration (also referred to as a second configuration). The closed configuration may provide protection for the electronic device  102 . In the particular configuration shown in  FIG. 1 , the article  100  takes the form of a stand that supports (thereby defining at least one form of a support configuration) the electronic device  102  at an inclination angle to provide a better viewing angle for users. 
     The article  100  can include a first segment  104   a , which can sometimes also be referred to as an input segment or a base due to the first segment  104   a  carrying an input device(s)  106  on an interior surface  108   a  of the first segment  104   a  that is opposite an exterior surface  108   b  (of the first segment  104   a ). The input device  106  can communicate with and provide input commands to the electronic device  102 . The input device  106  can take the form of a keyboard, a track pad, a touch-sensitive display, a scanner, any other suitable input devices, and/or any combinations thereof. The article  100  can include a second segment  104   b  that is pivotally coupled to the first segment  104   a  via a first hinge assembly  112   a . The first hinge assembly  112   a  may include a rotational element. As shown, the first hinge assembly  112   a  is located at a first edge  114   a  of the second segment  104   b . The second segment  104   b  can include an interior surface  118   a  and an exterior surface  118   b  that is opposite the interior surface  118   a . The article  100  can include a third segment  104   c  that is pivotally coupled to the second segment  104   b  via a second hinge assembly  112   b . The second hinge assembly  112   b  may include a second rotational element at a second edge  114   b  of the second segment  104   b . The third segment  104   c  can include an interior surface  128   a , to which the electronic device  102  can removably attach, and an exterior surface  128   b  opposite the interior surface  128   a . Because the electronic device  102  can be removably attached to the third segment  104   c , the third segment  104   c  can sometimes be referred to as an attachment segment, an attachment panel, a back cover, a support, and/or a support segment. Also, the second segment  104   b  can sometimes be referred to as an intermediate segment because it is positioned between the first segment  104   a  and the third segment  104   c . By rotating the segments, the article  100  can be arranged into different configurations. This will be shown and described below. It should be understood that the article  100  could include other components, some of which will be discussed in more detail. Also, while the first hinge assembly  112   a  and the second hinge assembly  112   b  are described as hinge assemblies, those skilled in the art would understand that the hinge assemblies do not have to be hinge assemblies. The first hinge assembly  112   a  and the second hinge assembly  112   b  can be any suitable hinge assemblies. 
     The segments described herein can each include internal structural components such as frames and/or plates formed from rigid materials such as metals (e.g. aluminum), alloys, reinforced polymers, other suitable materials, and/or any combinations thereof to provide the structural rigidity to the segments. The internal structural elements can be mounted or connected to the first hinge assembly  112   a  and/or the second hinge assembly  112   b . The segments can also include other internal components such as circuitry that can be used for different purposes including communication with the electronic device  102 . The internal components can be wrapped with any suitable materials. In one case, the external enclosure can be formed from flexible materials such as fabrics, leathers, rubbers, silicone, other flexible plastic, other flexible polymers, or any suitable combination thereof. In another case, the external enclosure can be formed from more rigid materials such as high-density polyvinyl chloride, high-density polycarbonate, high-density polyethylene, carbon fiber, fiberglass, metal (e.g., aluminum), wood, any other suitable materials, or any combination thereof. Some of the materials of the external enclosure, especially for the third segment  104   c , can be radio-transparent materials so that the materials do not block the radio transmission and reception of the electronic device  102 . In some cases, the enclosures of different segments can be formed from the same materials to give a coherent appearance to the article  100 . In other cases, the enclosures for different segments can be formed from different materials to provide contrasting appearance among the segments of the article  100 . 
     The hinge assemblies described herein can be any types of suitable hinges such as friction hinges and detent hinges. Some hinge assemblies can include conventional clutch mechanisms while other hinges can be of more specific types such as layered friction hinges, yoga geared hinges, or any other suitable hinges. The first hinge assembly  112   a  and/or the second hinge assembly  112   b  in the article  100  can have specific stiffness and torque friction so that article  100  can withstand the weight of electronic device  102  and statically maintain the configurations of article  100 , such as when article  100  is in a support configuration shown in  FIG. 1 . The first hinge assembly  112   a  and/or the second hinge assembly  112   b  described herein can also include spring loaded hinges, or can include torsion bars so that the torque required to turn the hinge assemblies can vary based on the angles of the hinge assemblies and the directions of the turning. In addition, the first hinge assembly  112   a  and/or the second hinge assembly  112   b  described herein can also include certain angular limits so that the two segments coupled with the first hinge assembly  112   a  or the second hinge assembly  112   b  can only be rotated within a certain angular range. Different hinge assemblies in the article  100  can have different properties in terms of the stiffness, torque, angular limit, and etc. Detailed properties of the hinge assemblies in the article  100  will be discussed below. 
     Referring to the electronic device  102 , the electronic device  102  may include a portable electronic device such as a tablet computer or a smart phone. The electronic device  102  can include a housing  132 , or enclosure, and may include a front surface  134   a  (or first surface) and a rear surface  134   b  (or second surface). The front side of the housing  132  can have edges that define an opening at which a display assembly  136  is carried. The display assembly  136  may present visual information, in the form of still images and/or videos. The display assembly  136  can include a capacitive touch sensitive layer designed to receive a touch input to alter the visual information. Also, the electronic device  102  can include a protective layer that overlays the display assembly  136 . The protective layer can include a transparent material, such as glass or sapphire, as non-limiting examples. 
     Referring to  FIGS. 2A and 2B , a side view and an isometric view, respectively, of a closed configuration of the article  100  covering the electronic device  102  are illustrated. In the closed configuration, the electronic device  102  can be sandwiched between the segments of the article  100  so that the article  100  can provide protection and/or improve the appearance of the electronic device  102 . The first segment  104   a  may include a size and shape generally in accordance with the electronic device  102  and can cover the front surface  134   a  of the electronic device  102 . In other words, the first segment  104   a  can generally overlay the front surface  134   a  of the electronic device  102  and cover the entirety of display assembly  136  so that the input device  106 , located on the interior surface  108   a  of the first segment  104   a , can be in a close proximity to the display assembly  136  while the exterior surface  108   b  of the first segment  104   a  can be the external facing surface, as shown in  FIG. 2A . In some embodiments, the first segment  104   a  can be of sufficient size to cover the front surface  134   a  of the electronic device  102  in its entirety. 
     The second segment  104   b  and the third segment  104   c  can be smaller than the first segment  104   a . However, when combined, the second segment  104   b  and the third segment  104   c  can also have a size and shape generally in accordance with the electronic device  102 . In other words, the combined surface area of the second segment  104   b  and the third segment  104   c  is about the same as the area of the first segment  104   a . Hence, the second segment  104   b  and the third segment  104   c  can cooperate to overlay the rear surface  134   b  the electronic device  102  when the second segment  104   b  and the third segment  104   c  are planar to each other, as shown in  FIG. 2A . Accordingly, the interior surface  118   a  of the second segment  104   b  and the interior surface  128   a  of the third segment  104   c  can overlay the rear surface  134   b . However, the rear surface  134   b  may extend beyond the aforementioned interior surface individually. Also, although not shown, the third segment  104   c  can include a mechanism that is capable of securing the rear surface  134   b  to the interior surface  128   a  of third segment  104   c . In the closed configuration, the interior surface  118   a  of second segment  104   b  and the interior surface  128   a  of third segment  104   c  can be in a close proximity to the rear surface  134   b . The exterior surface  118   b  of the second segment  104   b  and the exterior surface  128   b  of the third segment  104   c  can be the external facing surfaces, as shown in  FIG. 2A . Also, in a closed configuration, the first segment  104   a  can be in a rotational relationship with respect to the second segment  104   b  and the third segment  104   c , allowing the first segment  104   a  to generally overlay a protective layer (not shown in  FIGS. 2A and 2B ) of the electronic device  102 . 
     Referring specifically to  FIG. 2B , the first hinge assembly  112   a  can include a retainer that can retain another accessory device (e.g. a digital pen) for use with the electronic device  102 . For example, the first hinge assembly  112   a  may include a hollow body that can include an opening  140  at one end and internal components  142 , such as bushings, cams, bearings and springs, at a second (opposite) end. The hollow body of the first hinge assembly  112   a  can serve as a retainer that can receive a digital pen  144 . If the digital pen  144  requires power to operate, the first hinge assembly  112   a  can additionally include a charger  146  near the second end of the first hinge assembly  112   a . However, other locations along the first hinge assembly  112   a  are possible. It should be noted that while a retainer for the digital pen  144  is shown to be the body of the first hinge assembly  112   a , a retainer for the digital pen  144  could also be in other forms and/or be located at other locations. In some cases, both the digital pen  144  and the article  100  can include magnetic elements so that the digital pen  144  can be removably attached to the article  100  through magnetic coupling. For example, the digital pen  144  can include a magnet and the segments of the article  100  can include ferromagnetic material such as a ferromagnetic metal. Hence, the digital pen  144  can be attached to any segments of the article  100 . 
       FIG. 3  illustrates a side view of a support configuration of the article  100  carrying the electronic device  102 . This configuration can resemble a configuration of a laptop computer in which the first segment  104   a  carrying the input device  106  can serve as a base portion while the electronic device  102  can serve as a display portion. Due in part to the second hinge assembly  112   b  positioned between the second segment  104   b  and the third segment  104   c , the user can adjust the viewing angle of the electronic device  102 . 
     In this configuration, the article  100  and the electronic device  102  can be in an equilibrium state, meaning the segments and the electronic device  102  are at a balanced and static state without additional support or external force. In this state, the second segment  104   b  can be at an acute angle relative to the first segment  104   a , as denoted by angle θ 1 . Hence, second segment  104   b  is inclined and elevated relative the first segment  104   a . It should be understood that the angle θ 1  is less than 90 degrees. The inward inclination of the second segment  104   b , due to the acute angle, can shift the center of gravity of the system inwards so that the entire system can achieve equilibrium. In one specific embodiment, at this equilibrium state, the electronic device  102  is only attached to and supported by the third segment  104   c . Moreover, in that specific embodiment, the third segment  104   c  is only supported by second segment  104   b . Also, the second hinge assembly  112   b  can support and suspend the third segment  104   c  and the electronic device  102  so that the third segment  104   c  can be further elevated from the second segment  104   b  and inclined away from the first segment  104   a . In this manner, the third segment  104   c  can be at an obtuse angle relative to the first segment  104   a , as denoted by an angle θ 2 . It should be understood that the angle θ 2  is between 90 and 180 degrees. Also, a lower edge  148  of the electronic device  102  can align with a top edge  150  of the input device  106 . 
     As shown in  FIG. 3 , the electronic device  102  can be suspended (i.e. elevated) from the first segment  104   a  such that the electronic device  102  is separated from the first segment  104   a  by a gap  152 . In this manner, the electronic device  102  is not restricted at any point other than at the second hinge assembly  112   b . As a result, the viewing angle of the electronic device  102  can be more readily and easily adjusted. Also, due in part to the elevation of the electronic device  102 , the viewing position of the electronic device  102  may be enhanced for a user, as the electronic device  102  is closer to the user (as opposed to the electronic device  102  resting on the first segment  104   a . However, in other embodiments (not shown in  FIG. 3 ), the lower edge  148  of the electronic device  102  can be in contact with the first segment  104   a  to provide additional support of the electronic device  102 . In this case, article  100  may include a stop at a location corresponding to the contact position between the first segment  104   a  and the electronic device  102 . The stop can fix the position of the electronic device  102  relative to the first segment  104   a.    
     The hinge assemblies (i.e., rotational elements) of the article  100  may include a specific stiffness that can withstand the weight of the segments and the electronic device  102 . The stiffness of a hinge assembly can be described in terms of the torque friction (i.e. minimum torque required) to turn the hinge assembly in one direction. 
     A hinge assembly can provide a constant and/or variable torque depending on specific design and user considerations. For example, when the design requires that one segment of the article retains a fixed position, or angular displacement, relative to another segment in a support configuration, the hinge assembly can provide an overall hinge assembly torque that can balance a torque generated by a load in the support configuration. Accordingly, the hinge assembly can include a number of torque generating components, each of which provide a torque τ i  that combine to provide the overall hinge assembly torque in accordance with Equation (1) below. Equilibrium requires that hinge torque τ hinge  be equal to or greater than a maximum value of the torque τ load  of the load. 
       τ hinge =Σ 1   n τ I ≥τ load   Eq (1).
 
     It should be noted that the hinge assembly can include a constant torque component, such as a friction clip, that engages a rotational component (such as a shaft) with frictional force F f  applied at a surface of the rotational component a distance r s  from an axis of rotation resulting in constant torque τ const  according to Equation (2): 
       τ const   =F   f   *r   s   Eq. (2).
 
     Moreover, the hinge assembly can also include a variable torque component such as a torsional element (or spring element) that provides a torque in accordance with the angular displacement (θ) of the base that can provide variable torque τ var  in accordance with Equation (3): 
       τ var ∝φ  Eq. (3)
 
     where φ represents a twist angle from an equilibrium position. In this way, by combining the various torque components, each of the first hinge assembly  112   a  and the second hinge assembly  112   b  can be customized to provide a torque profile in accordance with the specific design and kinematic requirements of the article  100 . 
     In a particular case, the torque of a load τ load  can be related to a perpendicular component of the weight W of the load relative to a pivotal point (e.g. an axis of rotation of a hinge assembly) multiplied by the distance D between the center of gravity of the load and the pivotal point in accordance to Equation (4) below. The center of gravity of a load can depend on the relative weights, sizes and dimensions of the components (e.g. segments of the article  100  and/or the electronic device  102 ) of the load. 
       τ lid   =W   perpendicular   *D   Eq. (4).
 
     For example,  FIG. 3  is labeled with a center of gravity C 1  of the total of the electronic device  102  and the third segment  104   c . The location of the center of gravity C 1  is exemplary only because the location can depend on the relative weights, sizes and dimensions of the segments and the electronic device  102 . In this particular orientation, the torque exerting on the second hinge assembly  112   b  by a load (which can be the total of the weight of the electronic device  102  and the third segment  104   c  in this particular case) can be equal to a perpendicular component (labeled by arrow W p ) of the weight of the load multiplied by the distance D 1  between the center of gravity C 1  and the second hinge assembly  112   b . However, it should be noted that the perpendicular component W p  of the weight of the load is variable because the third segment  104   c  is rotatable relative to second segment  104   b  so that the second hinge assembly  112   b  can experience different amounts of torque from the load based on different orientations of the third segment  104   c . To maintain the entire system in the equilibrium state, the second hinge assembly  112   b  can have a torque friction that is greater than a maximum torque exerted by the load, which can be greater than the torque exerted by the load at the orientation illustrated in  FIG. 3  because it can reasonably be expected that a user might lift the entire system and put the system at different orientations. The torque friction the third segment  104   c  should be sufficiently large such that the system can remain stationary at any orientation. In some cases, the torque friction can be at least equal to the total weight of electronic device and the third segment  104   c  multiplied by distance D 1 . In other cases, the torque friction can be significantly greater than the maximum torque exerted by the load so that the entire system can be relatively stiff. Hence, without any external force, such as a force by a user turning the segments, the article  100  supporting the electronic device  102  can maintain stationary at the configuration shown in  FIG. 3 . 
     Similarly, the first hinge assembly  112   a  can also have a stiffness that can withstand the torque exerting on the first hinge assembly  112   a  by the weight of the electronic device  102 , the third segment  104   c , and second segment  104   b  combined. By having hinge assemblies that are stiff, the article  100  can maintain the configuration shown in  FIG. 3  in an equilibrium state. 
       FIGS. 4A-4C  illustrate the rearrangement from a closed configuration of the article  100  to a support configuration. The closed configuration of the article  100  shown in  FIG. 4A  can first be turned to a V-shaped intermediate configuration shown in  FIG. 4B  by turning the first hinge assembly  112   a  to rotate the second segment  104   b  together with the third segment  104   c  away from the first segment  104   a  (i.e. in a direction R 1 ). At the intermediate configuration shown in  FIG. 4B , the second segment  104   b  and the third segment  104   c  can be planar to each other and both segments can be at an acute angle relative to the first segment  104   a . At this state, a center of gravity C 2  of the total of the electronic device  102 , the second segment  104   b , and the third segment  104   c  can be near the midpoint of the electronic device  102 . The first hinge assembly  112   a  should have a stiffness that can withstand the torque exerted by the total weight of the electronic device  102 , the second segment  104   b , and the third segment  104   c . From the intermediate configuration in  FIG. 4B  to the support configuration in  FIG. 4C , the second hinge assembly  112   b  can then be turned in the direction R 1  to further rotate the third segment  104   c  away from the first segment  104   a  until the third segment  104   c  is at a right angle or an obtuse angle relative to the first segment  104   a . In the entire transition from the closed configuration to the support configuration, the electronic device  102  can retain the article  100 . 
     The first hinge assembly  112   a  and the second hinge assembly  112   b  may include features that facilitate the transition of the article  100  and maintain the support configurations of the article  100 . As shown in  FIG. 4C , the first hinge assembly  112   a  may limit the angle between the first segment  104   a  and the second segment  104   b  to an angle θ 3 , which may include an acute angle. When the first segment  104   a  and the second segment  104   b  are separated by the angle θ 3 , a rotational part of the first hinge assembly  112   a  meets a hard stop (such as pressing against a wall) so that the second segment  104   b  cannot go beyond the angle θ 3  in a direction R 1 . In other words, the first hinge assembly  112   a  may include an angular range of motion less than 90 degrees (corresponding to the angle θ 3 ) such that the second segment  104   b  is only rotatable relative to the first segment  104   a  at an angle that is less than 90 degrees. The angular limit of the first hinge assembly  112   a  can serve at least two purposes. First, the angular limit can allow the article  100  to naturally transition from the V-shaped intermediate configuration shown in  FIG. 4B  to the support configuration shown in  FIG. 4C . After the second segment  104   b  and the third segment  104   c  turn together away from the first segment  104   a  (in the direction R 1 ) and reach the angular limit of first hinge assembly  112   a , the only hinge that is rotatable in the same direction is the second hinge assembly  112   b . In this regard, the second hinge assembly  112   b  can start to turn after first hinge assembly  112   a  is at the angular limit (that is, the angle θ 3 ). Second, the angular limit of the first hinge assembly  112   a  can balance of the entire system. For the support configuration shown in  FIG. 4C , a center of gravity C 3  of the entire system (i.e. the article  100  and the electronic device  102 ) is shown. Even though all of the hinge assemblies can be stiff enough to withstand different weights of the components in the system so that segments does not rotate relative to each other without any external force, the entire system could still tip over at a pivot point, such as at the location of the first hinge assembly  112   a  in the direction R 1 , should the system become unbalanced. This is due in part to the electronic device  102  being significantly heavier than the first segment  104   a . The angular limit of the first hinge assembly  112   a  can depend on the location of center of gravity C 3 . The angular limit θ 3  can shift the center of gravity C 3  inwards, and thus, balance the entire system. In some cases, the angle θ 3  may include a value in the range of 30 to 75 degrees. In one embodiment, the angle θ 3  is 60 degrees. 
     The second hinge assembly  112   b  may also include one or more angular limits. For example, the second hinge assembly  112   b  may include a first hard stop at 180 degrees. In other words, for a turn direction towards the first segment  104   a  in a direction R 2  (as shown in  FIG. 4B ), the third segment  104   c  can, at most, turn planar relative to the second segment  104   b . This hard stop can prevent the third segment  104   c  and the second segment  104   b  from forming an outwardly protruding angle at the second hinge assembly  112   b  when the article  100  is in the closed configuration, which can be aesthetically unpleasing. As shown in  FIG. 4C , the second hinge assembly  112   b  may include a second hard stop at an angle θ 4 . The angle θ 4  may include a value within a range of 60 to 120 degrees. In other words, for a turn direction away from the first segment  104   a  (in the direction R 1 ), the minimum angle between the second segment  104   b  and the third segment  104   c  may include the angle θ 4 . Once the second hinge assembly  112   b  reaches this angular limit (at the angle θ 4 ), the third segment  104   c  can no longer further turn away from the first segment  104   a  (in the direction R 1 ). This second hard stop can ensure that, at the support configuration shown in  FIG. 4C , the third segment  104   c  does not continue to turn in the direction R 1 , thereby preventing the third segment  104   c  (and the electronic device  102 ) from becoming parallel or even downward relative to the first segment  104   a . Due in part to the two hard stops of the second hinge assembly  112   b , the second hinge assembly  112   b  may include an angular range of motion within approximately 60 and 180 degrees such that the third segment  104   c  can only be rotated relative to the third segment  104   c  only within the angular range of motion. 
     The first hinge assembly  112   a  and the second hinge assembly  112   b  can cooperate with the second segment  104   b  to form a cascading rotational support system. A cascading rotational support system can refer to two or more rotational supports (such as hinge assemblies) that are related or connected to each other based on torques, turn orders, and/or other qualities. For example, the first hinge assembly  112   a  and the second hinge assembly  112   b  may include asymmetrical torques that can be related to each other so that the first hinge assembly  112   a  and the second hinge assembly  112   b  can move in certain specific orders. Asymmetrical torques can refer to hinge assemblies that may include different torque frictions in different rotational directions. In one embodiment, for a first rotational direction that rotates the second segment  104   b  away from the first segment  104   a , the first hinge assembly  112   a  may include a first torque friction that is lower than a first torque friction of the second hinge assembly  112   b  in the first rotational direction (i.e., in the direction R 1  as denoted in  FIGS. 4B and 4C ). On the other hand, for a second rotational direction that rotates the second segment  104   b  towards the first segment  104   a , the first hinge assembly  112   a  may include a second torque friction that is greater than a second torque friction of the second hinge assembly  112   b  in the second rotational direction (i.e., in the direction R 2  as denoted in  FIG. 4B ). In one instance, the torque friction of first hinge assembly  112   a  in the direction R 1  can be lower than the torque friction of the second hinge assembly  112   b  in both the direction R 1  and the direction R 2 . 
     The hinge assemblies described herein can include detent hinges or friction hinges that can be adjusted based on the system requirement. In some cases, the hinge assemblies can also be spring loaded or can be coupled with torsion elements to vary the torque friction of the hinge assemblies relative to the angles and/or directions of the hinge assemblies. In general, first hinge assembly  112   a  may include a lower resistance in the direction R 1  than in the direction R 2  so that it requires less external force (from a user) to open the article  100  from the closed configuration in  FIG. 4A  than closing the article  100  from the support configuration in  FIG. 4C . In one case, the first hinge assembly  112   a  can be a detent hinge that has a relatively high torque frictions at zero degrees (referring to the closed configuration in  FIG. 4A ) and at the angle θ 3  (referring to the angular limit), and relatively low torque friction in between so that the first hinge assembly  112   a  may include a tendency to stay at either the zero-degree angle shown in  FIG. 4A  or the angular limit shown in  FIGS. 4B and 4C . In some cases, when the first hinge assembly  112   a  is at the angle θ 3  (shown in  FIG. 4C ), the torque friction of the first hinge assembly  112   a  in the direction R 2  can be significantly higher than any other torque frictions in the system so that first hinge assembly  112   a  can provide the most stable support to the system at the configuration shown in  FIG. 4C . Also, a cam or a spring can be used in the first hinge assembly  112   a  to bias the first hinge assembly  112   a  in the direction R 2 , thereby biasing the system to the closed configuration shown in  FIG. 4A  to help the segments of the article  100  to stay close with the electronic device  102 . 
     In addition, a cascading rotational support system can be achieved by adjusting the relative torque frictions between the first hinge assembly  112   a  and the second hinge assembly  112   b . A cascading rotational support system can also be achieved by mechanically and/or electrically connecting the first hinge assembly  112   a  and the second hinge assembly  112   b  so that some torque from the first hinge assembly  112   a  can be transferred to the second hinge assembly  112   b , or vice versa. By having specific relationship between the hinge assemblies, the order of rotation of the hinge assemblies can be specified. 
     The cascading rotational support system and the presence of hard stops can facilitate a natural transition between the closed configuration shown in  FIG. 4A  and the support configuration shown in  FIG. 4C . In order to open or closed the system, users may naturally or conveniently apply a turning force near the top edge  154  (labeled in  FIGS. 4B and 4C ) of the electronic device  102 . From the closed configuration in  FIG. 4A  to the intermediate configuration in  FIG. 4B  in the direction R 1 , the second hinge assembly  112   b  can remain stationary while the first hinge assembly  112   a  rotates even a force is applied at top edge  154  because the torque friction of the second hinge assembly  112   b  is greater than the torque friction of the first hinge assembly  112   a  in the direction R 1 . Hence, the third segment  104   c  can remain planar with the second segment  104   b  in the intermediate configuration of  FIG. 4B  until the first hinge assembly  112   a  reaches the hard stop at the angle θ 3 . Once the first hinge assembly  112   a  reaches the hard stop, the first hinge assembly  112   a  can no longer be turned in the direction R 1  and the second hinge assembly  112   b  can begin to turn in the direction R 1  so that the article  100  is transitioned from the intermediate configuration of  FIG. 4B  to the support configuration of  FIG. 4C  when a force continues to be applied at the top edge  154 . 
     In the support configuration of  FIG. 4C , the first hinge assembly  112   a  reaches the angular limit. As a result, the first hinge assembly  112   a  remains stationary without a user manually holding the second segment  104   b , and only the second hinge assembly  112   b  may continue to rotate. From the user&#39;s perspective, when the viewing angle of the electronic device  102  is adjusted, the first hinge assembly  112   a  is “locked.” In this regard, for turning the electronic device  102  in the direction R 1  (i.e. making the electronic device  102  flatter relative to the first segment  104   a ), only the second hinge assembly  112   b  may continue to rotate because the first hinge assembly  112   a  has already reached its angular limit. Further, for turning the electronic device  102  in the direction R 2  (i.e. making electronic device  102  steeper relative to first segment  104   a ), it is also only the second hinge assembly  112   b  that rotates in direction R 2  because the second hinge assembly  112   b  has a higher torque friction than the second hinge assembly  112   b  in the direction R 2 . Due in part to only the second hinge assembly  112   b  moving, the viewing angle of the electronic device  102  can be conveniently and finely adjusted by a user, even in instances when the user applies a force to the top edge  154 . 
     This asymmetrical torque friction hinge system with hard stops implemented can also allow a natural transition from the support configuration shown in  FIG. 4C  back to the closed configuration shown in  FIG. 4A . When the third segment  104   c  is rotated in the direction R 2  in the configuration of  FIG. 4C , the first hinge assembly  112   a  can remain stationary. When the third segment  104   c  continues to rotate in the direction R 2  all the way back to the intermediate configuration of  FIG. 4B , the second hinge assembly  112   b  will reach one of the aforementioned hard stops at 180 degrees. Moreover, in the intermediate configuration of  FIG. 4B , only the first hinge assembly  112   a  is rotatable in the direction R 2 . Hence, a torque in the direction R 2  can close the first hinge assembly  112   a  and turn the article  100  back to the closed configuration shown in  FIG. 4A . 
     The turn order of a cascading rotational support system can be specified in some embodiments even when a force is applied at the top edge  154 . For example, in a first rotational direction R 1  from the closed configuration (in  FIG. 4A ) to the support configuration (in  FIG. 4C ), the first hinge assembly  112   a  can be turned prior to the second hinge assembly  112   b  being turned. Conversely, in a second rotational direction R 2  from the support configuration (in  FIG. 4C ) to the closed configuration (in  FIG. 4A ), the second hinge assembly  112   b  can be turned prior to the first hinge assembly  112   a  being turned. 
     According to one embodiment, the cascading rotational support system can include a first rotation element coupled to the first segment  104   a  and a second segment rotation element coupled to the third segment  104   c  such that the cascading rotational support system can suspend, position and orient the electronic device  102  above the first segment  104   a  at a desirable viewing angle and position. When a first torque is applied to the third segment  104   c  (i.e. a force applied in a first rotational direction such as the direction R 1 ) to change the article  100  from a closed configuration to a support configuration, only the first rotation element can rotate until the first rotation element reaches a hard stop in the first rotational direction. When a second torque is applied to the third segment  104   c  (i.e. a second force applied in a opposite rotational direction such as direction R 2 ) to change the article  100  from a support configuration to a closed configuration, only the second rotation element can rotate until the second rotation element reaches a hard stop in the second rotational direction. The first rotation element and the second rotation element may each refer to a hinge assembly described herein. It should be noted that while various hard stops and asymmetrical torque friction hinge systems are described herein with a preferred embodiment, those features are only optional and should not be construed as limiting. 
     The article  100  may include additional features and components that provide added benefits and functionalities to the article  100  as well as to the electronic device  102 . For example,  FIG. 5  illustrates an isometric view of an electronic system showing the article  100  separated from the electronic device  102 . In some embodiments, the article  100  can include one or more attachment components that can be used to removably attach the electronic device  102 . For example, the article  100  may include a first attachment components  502   a , a second attachment component  502   b , a third attachment component  502   c , and a fourth attachment component  502   d . These attachment components can retain the electronic device  102  through frictional fit, magnetic coupling, mechanical fastening, and/or any other suitable combination. In this regard, in some embodiments, each of the first attachment components  502   a , the second attachment component  502   b , the third attachment component  502   c , and the fourth attachment component  502   d  are magnetic elements. As shown, the aforementioned attachment components are carried by the third segment  104   c . Further, the aforementioned attachment components can be embedded in the third segment  104   c  so as to not be visible. When the aforementioned attachment components are magnetic elements, the magnetic elements can be permanent magnets such as ceramic rare earth magnets (e.g., samarium-cobalt, neodymium, other rare earth magnets) or ferrous-based magnets. The aforementioned attachment components can also include a Halbach array of magnets. In other cases, some or all of the magnetic elements can be formed of magnetically attractive material, such as a ferromagnetic material (e.g., a ferrite, a ferrous metal or alloy of iron, nickel, or cobalt). The magnetic elements of the third segment  104   c  can form one or more magnetic circuits with the magnetic elements (not shown in  FIG. 5 ) located in the electronic device  102 , and as a result, the magnetic elements provide an attractive force to retain the electronic device  102 . In additional to retaining the electronic device  102 , the magnetic elements can be in a specific number and/or arranged in a specific pattern to align the magnetic elements of the electronic device  102  so that the electronic device  102  can be aligned with the third segment  104   c  in a specific manner (e.g., align along the edges). 
     In another embodiment, each of the first attachment components  502   a , the second attachment component  502   b , the third attachment component  502   c , and the fourth attachment component  502   d  can take the form of mechanical fastener. For example, pairs of lock and loop fasteners such as Velcro can be use. For example, the aforementioned attachment components can provide loops, while the housing of the electronic device  102  provides locks. In yet another embodiment, each of the first attachment components  502   a , the second attachment component  502   b , the third attachment component  502   c , and the fourth attachment component  502   d  can utilize frictional fit to retain the electronic device  102 . For example, although not shown in  FIG. 5 , the third segment  104   c  may not be flat. Rather, each of the aforementioned attachment components can form sidewalls along the third segment  104   c  that cooperate with the third segment  104   c  to define a recessed region that may include a size and shape in accordance with the electronic device  102  (or portion thereof) in order to receive and retain the electronic device  102  through friction fit. While several possible configurations of the aforementioned attachment components are described herein, those skilled in the art would understand that those are merely non-limiting examples. 
     In some embodiments, the article  100  includes an interface  504  that allows the exchange of information and power between the article  100  and the electronic device  102 . The article  100  can include an internal electrically conductive material, such as flexible circuitry or an electrically conductive fabric, used to electrically couple the input device  106  and the electronic device  102 . While the interface  504  is located on the third segment  104   c , those skilled in the art would understand that the location is only exemplary and is not limiting. The interface  504  can allow the input device  106  to provide and/or exchange commands with the electronic device  102 . As it will be discussed in further detail, the interface  504  may also allow the transfer of power to and/or from the article  100 . It should be noted that the interface  504  can also be referred as a charge terminal, an information terminal, an electrical contact, a transceiver, an antenna, a port, an inlet, a charge station, an inductive charge receiver or transmitter, a near-field communication (“NFC”) charge receiver or transmitter, a communication component or other suitable term as dictated by its particular features and functions. 
     In some embodiments, the interface  504  is an electrical contact such as a smart connector. The electronic device  102  may include a corresponding electrical contact (not shown in  FIG. 5 ) on the back of the electronic device  102 . Hence, when the electronic device  102  is attached to the third segment  104   c , the interface  504  can complete a circuit with the electrical contact of the electronic device  102  so that a direct connection is established between the article  100  and the electronic device  102 . In another embodiment (not shown in  FIG. 5 ), the interface  504  includes a connection port such as a USB and/or USB-C connection port that allows the article  100  to be electrically connected to the electronic device  102  via an electrical cable. In yet another embodiment, the interface  504  includes a short distance inductive communication component such as an NFC transceiver that communicates with the electronic device  102  through short-ranged protocols and exchanges power through inductive charging. In yet another embodiment, the interface  504  includes a wireless RF antenna that communicates using wireless protocols such as Bluetooth and/or Wi-Fi. While several possible types of the interface  504  are described herein, those skilled in the art would understand that those are merely non-limiting examples. 
     In some embodiments, the article  100  can include one or more power storage units  506 . The one or more power storage units  506  may include batteries and/or supercapacitors. As shown, the one or more power storage units  506  are carried by, and embedded in, the first segment  104   a  and the second segment  104   b . However, those skilled in the art would understand that the particular segments shown in  FIG. 5  as carrying the one or more power storage units  506  are only exemplary and are not limiting. The one or more power storage units  506  can be used to store energy supplied by the electronic device  102  and/or another charge source (e.g., a wall plug). The one or more power storage units  506  are capable of transferring electrical energy to the electronic components on the article  100 , which may include the input device  106 . Further, the one or more power storage units  506  are capable of transferring electrical energy to the electronic device  102  and/or to other devices, such as the digital pen  144 . 
     The article  100  may include a charge terminal  508  located in the first hinge assembly  112   a . The charge terminal  508  that can transfer energy from the one or more power storage units  506  to the digital pen  144  when then digital pen  144  is inserted into the opening  140  defined by the hollow body of the first hinge assembly  112   a . The one or more power storage units  506  can be connected to the input device  106 , the interface  504 , and the charge terminal  508  through internal circuitry (not shown in  FIG. 5 ), such as printed circuit boards, cables, and/or flexible circuits. 
     In some cases, the article  100  can include a power inlet  510 . The one or more power storage units  506  can be charged by an external power source (e.g. a wall plug or a USB power source) via the power inlet  510 . The power inlet  510  can be a standard charging port such as a USB or USB-C connection port, a plug-in for a direct DC connection (or an AC source with a transformer), a customized charging inlet, and/or any other suitable power inlet. The power inlet  510  can be located at the first segment  104   a  or can be located at any other suitable location(s) of the article  100 . The power inlet  510  can be used to charge the one or more power storage units  506 , which in turn can transfer the energy to the electronic device  102 , so that the article  100  can act as supplemental power source for the electronic device  102 . In some cases, the power inlet  510  may also be used to directly charge the electronic device  102  and/or the digital pen  144 . In some cases, the article  100  can include additional ports that allow information exchange between the article  100  and another electronic device (not shown in  FIG. 5 ), such as a mouse that can be used to control portable the electronic device  102 . For example, an additional port can include a USB-C connection port. 
     In some embodiments, the electronic device  102  can supply energy to the electronic components of the article  100  (e.g. the input device  106 ) through the interface  504 . In this regard, in some embodiments (not shown in  FIG. 5 ), the one or more power storage units  506  are not integrated into the article  100 . The digital pen  144 , when retained by the first hinge assembly  112   a , can also be charged by the energy supplied by the electronic device  102 . 
     In some embodiments, the article  100  may not include the input device  106 . In other embodiments, the input device  106  can be of different types. In one particular embodiment, the input device  106  is a keyboard. In these embodiments, the input device  106  may include different designs that can include different materials, coating, and components such as a rubber dome, a metal dome, and/or any suitable combination. The input device  106  can include backlights whose power can be supplied either by the one or more power storage units  506  or directly from the electronic device  102 . Further, when the input device  106  is a keyboard, the input device  106  includes a membrane or fabric layer that acts as a cosmetic or functional seal layer. The seal of the input device  106  may include hard rigid keycaps above the fabric layer. Some or all keys of the keyboard can also contain a touch sensor to facilitate multi-touch sensing of a key. Also, in some embodiments, the first segment  104   a  includes a touch sensor  512  that can serve as a track pad. 
     In another embodiment (not shown in  FIG. 5 ), alternative to or in addition to a keyboard, the input device  106  includes a touch sensor, such as a capacitive touch sensor. For example, the input device  106  can occupy a substantial area, including a large majority of the interior surface  108   a  of the first segment  104   a . The touch sensor can support multi-touch sensing. Users can control the electronic device  102  via the touch sensor of the input device  106  through different finger movements and gestures. In yet another embodiment (not shown in  FIG. 5 ), the input device  106  includes a display assembly with touch sensing ability. Hence, the input device  106  can provide different images to the user, by way of the display. In one case, the electronic device  102  can control the display of image data of the input device  106 . In another case, the article  100  can include a processor that controls or that works with the electronic device  102  to control the display of image data. In one instance, the input device  106  can display a virtual keyboard. In yet another embodiment, the input device  106  can be removably coupled to the first segment  104   a . In some cases, the entire or part of the first segment  104   a  can be removably coupled to the article  100 . Hence, a first type of the input device  106  can be replaced with a second input device or a second type of input device. For example, a keyboard can be removably coupled to the article  100  and can be replaced by a track pad. In some cases, one type of the input device  106  can include another portable electronic device having a touch screen display assembly. Hence, a second portable electronic device can replace the first segment  104   a  (or part thereof) and can electrically couple with the electronic device  102  through the circuitry of the article  100  and the interface  504 . 
     In some embodiments, the electronic device  102  can detect the configuration of the article  100  and automatically switch to different operating modes based on the configuration of the article  100 . For example, the article  100  can include a first triggering element  514   a  along an edge of the first segment  104   a  such that the first triggering element  514   a  aligns with an edge of the electronic device  102 . The article  100  may further include a second triggering element  514   b  along an edge of the second segment  104   b  such that the second triggering element  514   b  aligns with an edge of the electronic device  102 . The first triggering element  514   a  and the second triggering element  514   b  can work in conjunction with a first sensor and a second sensor (not shown in  FIG. 5 ), respectively, of the electronic device  102 . The first sensor and the second sensor can be connected to a processor. The sensors can include magnetic sensors (e.g. Hall effect sensors, magnetometers, etc.), optical sensors, wireless sensors and other types of suitable sensors. The first triggering element  514   a  and the second triggering element  514   b  may include any corresponding suitable elements. For example, when the sensors are magnetic, the first triggering element  514   a  and the second triggering element  514   b  can be magnetic elements such as permanent magnets or ferromagnetic metals. When the sensors are optical sensors, the first triggering element  514   a  and the second triggering element  514   b  can be a light source such as a LED light source. 
     This arrangement of sensors can be used to detect when the article  100  is in a closed configuration (shown in  FIG. 4A ) or in other configurations such as the support configuration (shown in  FIG. 4C ). In the closed configuration, both the first triggering element  514   a  and the second triggering element  514   b  can be brought in a close proximity to the electronic device  102 . In a support configuration, both the first triggering element  514   a  and the second triggering element  514   b  can be brought away from the electronic device  102 . Based on the detection the first triggering element  514   a  and/or the second triggering element  514   b  by the sensors, the processor of the electronic device  102  can deduce the configuration of the article  100 . The electronic device  102  can automatically enter different operating modes based on the configuration of the article  100 . For example, when the article  100  is in the closed configuration, the electronic device  102  can transition to an inactive mode such as a sleep mode. 
     In addition to various electronic features, the article  100  can also have additional mechanical features that enhance the capabilities of the article  100 . For example, since the second segment  104   b  can be an intermediate segment that connects to the first segment  104   a  and the third segment  104   c , the second segment  104   b  can be primarily responsible for the dampening the system. The second segment  104   b  can include structural elements that are stiff, but less stiff compared to other segments and/or hinge assemblies of the article  100 . Due in part the location of the second segment  104   b , the second segment  104   b  can act effectively as a spring that provides dampening to the article  100  against vibrations caused by situations such as when a user is carrying the system in a moving automobile. In some instances, the second segment  104   b  can deflect more than half of the amplitude of a given vibration. 
     The second segment  104   b  can include additional internal structural to provide dampening to the article  100 . For example, the enlarged partial cross-sectional view shows internal layers of the second segment  104   b , which can utilize constrained layer damping principles to provide damping to the electronic device  102 . The second segment  104   b  can include a substrate layer  516 , which can define a main structural layer of the second segment  104   b . The second segment  104   b  can further include a secondary structural layer  518 . The second segment  104   b  can further include a viscoelastic material  522  that defines a layer sandwiched between the substrate layer  516  and the secondary structural layer  518 . The second segment  104   b  can further include a first layer  524   a  and a second layer  524   b . The first layer  524   a  can combine with the second layer  524   b  to wrap around and can cover the substrate layer  516 , the secondary structural layer  518 , and the viscoelastic material  522 . The substrate layer  516  and the secondary structural layer  518  can be made from the same or different materials and may include the same or different thicknesses. Also, the substrate layer  516  and the secondary structural layer  518  can be significantly stiffer than the viscoelastic material  522 . When the system vibrates, the vibration can create shear at the viscoelastic material  522 . The viscoelastic material  522  can then covert the kinetic energy associated with the vibration into heat, thus providing dampening to the system. It should be noted that this internal structure does not have to be present on the second segment  104   b . Also, the internal structure can also be present on other segments of the article  100 . 
     Referring to the second hinge assembly  112   b , the second hinge assembly  112   b  can include a number of short segments connected in series. Hence, each segment may include a reduced overall contribution to the torque of the second hinge assembly  112   b . Because of the short segments, each segment can become effectively significantly stiffer. As a result, the second hinge assembly  112   b  can also become stiffer to withstand the weight of the electronic device  102 . The first hinge assembly  112   a  can also include similar types of hinge to increase the stiffness. 
       FIGS. 6A and 6B  illustrate two side views of an electronic system in different configurations, in accordance with some embodiments.  FIG. 6A  illustrates in a closed configuration and  FIG. 6B  illustrates in a support configuration. As shown, the electronic system includes an article  600 . Similar to the article  100  shown in  FIGS. 1-5 , the article  600  may include a multi-segment folio and can have any other features that are described in and associated with  FIGS. 1-5 . For example, the article  600  can include a first segment  604   a , a second segment  604   b , and a third segment  604   c . The article  600  may include a first hinge assembly  612   a  (acting as a first rotational element) connected to the first segment  604   a  and the second segment  604   b . The article  600  may further include a second hinge assembly  612   b  (acting as a second rotational element) connected to the second segment  604   b  and the third segment  604   c . The article  600  may carry an electronic device  602  in any manner previously described. 
     The third segment  604   c  can be further divided into two sub-segments. In this regard, the third segment  604   c  may include a first sub-segment  662   a  and a second sub-segment  662   b . The first sub-segment  662   a  can be coupled to the second sub-segment  662   b  via a third hinge assembly  612   c  (acting as a first rotational element) so that the first sub-segment  662   a  is rotatable relative to the second sub-segment  662   b . In one case, the third hinge assembly  612   c  can be located at or near the midline (shown as a dotted line in  FIG. 6A ) of electronic device  602 . In terms of the sizes of the segments, in one case, the first segment  604   a  can have a size and shape generally in accordance with electronic device  602 . The second sub-segment  662   b  can have half of the size of the first segment  604   a . The combination of the first sub-segment  662   a  and second segment  604   b  can also have half of the size of first segment  604   a . Accordingly, the size of the combination of the first sub-segment  662   a  and second segment  604   b  can equal the size of the second sub-segment  662   b . As shown in  FIG. 6B , in a support configuration, the article  600  can be arranged similar to the support configuration of article  100  shown in  FIGS. 1-5 . The second segment  604   b  can be at an acute angle relative to the first segment  604   a , similar to a manner previously described. Also, the first sub-segment  662   a  can be coupled to the second sub-segment  662   b  can remain planar to each other and third segment  604   c  can be at an obtuse angle relative to first segment  604   a , similar to a manner previously described. 
     Referring to  FIG. 6B , the article  600  can include a triggering element  614  carried by the second segment  604   b . The electronic device  602  can include a first sensor  620   a  at a top side of the electronic device  602  and a second sensor  620   b  at a bottom side of the electronic device  602 . It should be noted that the numbers, locations, and arrangements of triggering elements and sensors are exemplary only. Depending on the configuration of the article  600 , the second segment  604   b  can be positioned in different locations relative to electronic device  602 . Hence, the triggering element  614  may be sufficiently close to one of the first sensor  620   a  or the second sensor  620   b  so that the triggering element  614  may trigger either first sensor  620   a  or second sensor  620   b . This will be shown below. Alternatively, in some configurations, the triggering element  614  may not trigger any sensor at all. For example, in a support configuration shown in  FIG. 6B , the second segment  604   b  can be brought away from the electronic device  602 , and the triggering element  614  does not trigger any of the first sensor  620   a  or the second sensor  620   b.    
     In addition to the support configuration, the article  600  can be rearranged to another configuration that can be referred to as a clipboard configuration. For example,  FIGS. 7A-7D  illustrates a transition from a closed configuration shown in  FIG. 7A  to the clipboard configuration shown in  FIG. 7D . First, the article  600  can transition to a first intermediate configuration shown in  FIG. 7B  by turning the first hinge assembly  612   a  in a manner that causes the second segment  604   b  and the third segment  604   c  to move in a direction away from the first segment  604   a . Second, the article  600  can transition to a second intermediate configuration shown in  FIG. 7C  by turning the third hinge assembly  612   c  in a manner that causes the third segment  604   c  to move further in a direction away from the first segment  604   a . By turning the third hinge assembly  612   c , the second sub-segment  662   b  can rotate relative to the first sub-segment  662   a . Third, the third hinge assembly  612   c  can continue to turn so that the second sub-segment  662   b  can be folded onto both the first sub-segment  662   a  and the second segment  604   b . Further, the first hinge assembly  612   a  can be turned in a direction back to the first segment  604   a , as shown in the clipboard configuration in  FIG. 7D . The electronic device  602  can largely overlay the first segment  604   a  such that the edges of the electronic device  602  can align with the edges of the first segment  604   a . The rest of the segments can be stacked together and positioned between the electronic device  602  and the first segment  604   a  at one end of the electronic device  602 . The stacked segments can an inclination of the electronic device  602  relative to the first segment  604   a . Hence, this configuration can allow the article  600  to serve like a clipboard for the electronic device  602 . In the entire transition from the closed configuration to the clipboard configuration, the electronic device  602  can remain attached to the article  600 . 
     In a closed configuration shown in  FIG. 7A , the triggering element  614  can be in a close proximity of first sensor  620   a  to trigger the first sensor  620   a . For example, if the triggering element  614  is magnetic, the external magnetic field generated by the triggering element  614  has a field strength that, in the closed configuration, exceeds a threshold level of first sensor  620   a , thereby triggering the first sensor  620   a . In a clipboard configuration shown in  FIG. 7D , the triggering element  614  can be in a close proximity to the second sensor  620   b , and accordingly, can trigger the second sensor  620   b . It should be noted that because the second sub-segment  662   b  can be located between the triggering element  614  and the second sensor  620   b , the threshold level of the second sensor  620   b  can be set at a lower level than the threshold level of the first sensor  620   a . Based on the signals of the first sensor  620   a  and the second sensor  620   b , a processor (not shown) of the electronic device  602  can determine the configuration of the article  600  and may enter different operation states based on the configuration. 
       FIG. 8  shows a block diagram of a method  800  for automatically altering an operation state of a portable electronic device based on the configuration of an article removably coupled to the portable electronic device, in accordance with some embodiments. The portable electronic device may refer to an electronic device described herein and the article can refer to the article  100  (in  FIGS. 1-5 ) or the article  600  (in  FIGS. 6A-7D ). Also, the article may include a folio or cover for an electronic device described herein. The portable electronic device can include a first sensor and a second sensor, such as the first sensor  620   a  and the second sensor  620   b  in  FIGS. 6 and 7A -D. The folio can include one or more triggering elements such as the triggering element  614  in  FIGS. 7A-D . In one case, a second segment can carry the triggering element. 
     The method  800  can begin at step  802  when the electronic device is in a first mode that corresponds to a closed configuration of the folio. For example, an exemplary first mode can be an inactive mode such as a sleep mode. The method  800  can also include step  804 , which may include a decision stage that determines whether the first sensor is triggered. If the first sensor is triggered, the triggering element can be in proximity with the first sensor. This can be associated with a closed configuration where a second segment of the article covers at least part of a surface of the electronic device. Hence, the electronic device can remain in the first mode. If the first sensor is not triggered, the first sensor can send a signal to a processor of the electronic device. The receipt of such signal can indicate that the triggering element carried is no longer in proximity to the first sensor. At this stage, the method  800  can then proceed to step  806 . Step  806  may include another decision stage that determines whether the second sensor is triggered. If the second sensor is not triggered, then neither the first nor the second sensor is triggered, and the method  800  can then proceed to step  808 . This can be associated with a support configuration where the second segment is brought away from the electronic device (e.g. the configuration shown in  FIG. 3  or  FIG. 6B ). At step  808 , the processor can cause the electronic device to switch from the first mode to a second mode, which may correspond to the support configuration. Also, the second mode may include an active mode. In some cases, the support configuration can be associated with an active input device (e.g.  FIG. 3 ). Hence, at step  810 , the electronic device can provide energy to an input device carried by the article, such as a keyboard or a track pad, so that the input device is operational. In some cases, the input device may indicate to the user that power is received from the electronic device (such as by turning on an LED or turning on backlights of the keyboard). Referring back to step  806 , if the second sensor is triggered, the method  800  proceeds to step  812 , and processor can cause the electronic device to switch to a third mode, which corresponds to the clipboard configuration. The third mode may refer the article being in a clipboard configuration (e.g. the configuration shown in  FIG. 7D ). In some cases, the third mode can be the same as the second mode, which can also define an active mode. In other cases, the electronic device in the third mode can automatically launch an application such as a note-taking application or a drawing application because the clipboard configuration can be associated with a “scratch pad” configuration for users to use a digital pen. The exact application launched can be based on a user setting that is user selectable. After step  810  or  812 , the method can return to step  804  so that the processor of the electronic device can continue to monitor the status of the sensors in order to determine the configuration of the article. 
       FIG. 9  shows a block diagram  900  depicting a method for automatically altering operation of a portable electronic device based on different types of input devices in communication with the portable electronic device, in accordance with some embodiments. The input device can be removably coupled to an article so that an input device of the article is in communication with the portable electronic device through the circuitry of the article. The method can begin at step  902 . At step  902 , the electronic device can determine the type of the input device connected to the article through signal communication. At step  904 , the electronic device can optionally provide power to the input device based on the type of the input device determined. For example, in one case the input device may include a keyboard without backlights while in another case the input device may include a keyboard with backlights. In yet another case the input device has its own battery so that the electronic device can determine that no power is needed to provide to the input device. At step  906 , the electronic device can adjust its operation based on the type of the input device. For example, the electronic device can be configured to show a virtual keyboard on a display when a user selects an input field in a software application. However, when the input device is detected as a keyboard, the electronic device can alter its operation so the virtual keyboard is no longer shown. In another case, when the input device is detected to have a second display assembly, the electronic device can transmit image data to the input device. 
       FIG. 10  is a block diagram that illustrates circuitry of a computing device  1000  in accordance with some embodiments. The computing device  1000  may include an electronic device or an article described herein that includes a processor. An exemplary computing device can contain all or some of the components shown in  FIG. 10 . The computing device  1000  can include a processor  1002  that pertains to a microprocessor or controller for controlling the overall operation of the computing device  1000 . The computing device  1000  can store media data pertaining to media items in a file system  1004  and a cache  1006 . The file system  1004  can be, typically, a storage disk or multiple storage disks. The file system  1004  typically can provide high capacity storage capability for the computing device  1000 . However, since the access time to the file system  1004  can be relatively slow, the computing device  1000  can also include a cache  1006 . The cache  1006  may include, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to the cache  1006  can be substantially shorter than that for the file system  1004 . However, the cache  1006  does not have the large storage capacity of the file system  1004 . Further, the file system  1004 , when active, can consume more power than does the cache  1006 . The computing device  1000  can also include a RAM  1020  and a Read-Only Memory (ROM)  1022 . The ROM  1022  can store programs, utilities or processes to be executed in a non-volatile manner. The RAM  1020  provides volatile data storage, such as for the cache  1006 . The computing device  1000  may include a battery  1024  that provides electrical energy to components of the computing device  1000 . 
     The computing device  1000  can also include a user input device  1008  that allows a user of the computing device  1000  to interact with the computing device  1000 . For example, the user input device  1008  can take a variety of forms, such as a button, keypad, touch screen, audio input interface, visual/image capture input interface, input in the form of sensor data, etc. Still further, the computing device  1000  can include a display  1010  (screen display) that can be controlled by the processor  1002  to display information to the user. 
     In one embodiment, the computing device  1000  can serve to store multiple media items (e.g., songs, podcasts, etc.) in the file system  1004 . When a user desires to have the electronic device play a particular media item, a list of available media items can be displayed on the display  1010 . Then, using the user input device  1008 , a user can select one of the available media items. The processor  1002 , upon receiving a selection of a particular media item, can supply the media data (e.g., audio file) for the particular media item to a coder/decoder (CODEC)  1013 . The CODEC  1013  can then produce analog output signals for a speaker  1014 . The speaker  1014  can be a speaker internal to the computing device  1000  or external to the computing device  1000 . For example, headphones or earphones that can connect to the computing device  1000  would be considered an external speaker. 
     The computing device  1000  can also include a network/bus interface  1011  that couples to a data link  1012 . The data link  1012  can allow the computing device  1000  to couple to a host computer or to accessory articles. The data link  1012  can be provided over a wired connection or a wireless connection. In the case of a wireless connection, the network/bus interface  1011  can include a wireless transceiver. The media items (media assets) can pertain to one or more different types of media content. In one embodiment, the media items can be audio tracks (e.g., songs, audio books, and podcasts). In another embodiment, the media items can be images (e.g., photos). However, in other embodiments, the media items can be any combination of audio, graphical or visual content. The computing device  1000  may include a sensor  1026  that can take the form of circuitry for detecting any number of stimuli. For example, the sensor  1026  can include a Hall Effect sensor responsive to external magnetic field, an audio sensor, a light sensor such as a photometer, and so on. A data bus  1016  can facilitate data transfer between at least the file system  1004 , the cache  1006 , the processor  1002 , and the CODEC  1013 . 
     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 that 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.