You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND 
     The present invention relates generally to wireless communication devices having relatively moveable housing portions and, more particularly, to a hinge mechanism for connecting the relatively movable housing portions. 
     Wireless communications devices, such as cellular phones, personal digital assistants, and the like, frequently have two housing portions that are relatively moveable. For example, a common cell phone design is a so-called clamshell design, with a “flip” having a speaker and a display, and a base portion having a keypad and a microphone. The flip portion is connected to a base portion via a hinge. The flip portion rotates via the hinge between a closed position disposed proximate the base section in an overlying configuration and an open position where the flip and base are aligned end to end, similar to an open clamshell. The flip can typically be rotated open between about 90° and 180°, and sometimes more, relative to the base portion. 
     Wireless communications devices are rapidly adding functionality to the basic cell phone functionality. For example, many wireless communications devices can now be used for gaming, and/or for various business functions previously performed on office computers. For some of these additional functions, a traditional twelve-key phone keypad may be problematic, and a qwerty or similar keypad may be more desirable. Further, for many of these additional functions, a different screen orientation may be desired, such as one with a wider-than-tall orientation. Thus, as can be appreciated, while the conventional clamshell arrangement discussed above may be desirable when the device is used as a conventional cell phone, the conventional clamshell arrangement may be less desirable when the device is used for other purposes. 
     Therefore, while numerous wireless communications devices have been proposed, their configurations have not proven to be entirely satisfactory for some of the situations outlined above. Accordingly, there remains a need for alternative wireless communications device designs, advantageously ones that allow for a more user-friendly utilization of the device. 
     SUMMARY 
     In one illustrative embodiment, a wireless communications device, such as a cellular telephone, comprises a first body portion having a first perimeter and a second body portion having a second perimeter. A display is associated with one of the first and second body portions, and user input means is associated with the other. A hinge mechanism moveably couples the second body portion to the first body portion so that the second body portion may pivot between a closed state and an open state. The second body portion, while in the open state, is slidable from a first open position to a second open position along the first perimeter. The first and second open positions may be approximately 90° apart along the first perimeter. The first and second body portions may have respective major axes and the major axes may be disposed substantially parallel, and advantageously coincident, when the second body portion is in the first open position. Advantageously, the major axes may also be substantially parallel when the second body portion is in the second open position. The first and second perimeters may advantageously be substantially similar in shape, and advantageously generally oval. The operational orientation of the display may automatically change in response to the second body moving to the second open position. 
     In another embodiment, a wireless communications device comprises a first body portion having a first face and a longitudinal axis and a second body portion having a second face. A display is associated with one of the first and second body portions and user input means is associated with the other. A hinge mechanism moveably couples the second body portion to the first body portion so that the second body portion may pivot between a closed state and an open state relative to the first body portion. The second body portion, in the open state, is moveable relative to the first body portion such that a theoretical line from a midpoint of the first body portion along the longitudinal axis to a perimeter of the first body portion in a direction of the second body portion is variably oriented with respect to the longitudinal axis. The first body portion may include a first slot and the second body portion a second slot, with the hinge mechanism slidably disposed in the first and second slots. The hinge mechanism may comprise a first hinge plate associated with the first body portion and slidably mounted thereto and a second hinge plate associated with the second body portion and slidably mounted thereto. 
     In another embodiment, a wireless communications device comprises a first body portion; a second body portion distinct from the first body portion; and a display associated one of the first and second body portions and user input means associated with other. A hinge mechanism moveably couples the second body portion to the first body portion so that the second body portion may pivot between a closed state and an open state relative to the first body portion. The hinge mechanism comprises a first anchoring element associated with the first body portion and slidably mounted thereon for movement around a periphery thereof with the second body portion in the open state; a second anchoring element associated with the second body portion and slidably mounted thereon for movement around a periphery thereof with the second body portion in the open state; the first and second anchoring elements pivotally mated to one another for relative rotation about a pivot axis disposed generally tangent to a perimeter of the first body portion. 
     Other aspects of various embodiments of the inventive apparatus and related methods are also disclosed in the following description. The various aspects may be used alone or in any combination, as is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of one embodiment of a wireless communications device with its flip portion in the closed state. 
         FIG. 2  shows a simplified cross-sectional side view of the wireless communications device of  FIG. 1  with the flip portion in the open state. 
         FIG. 3  shows the wireless communications device of  FIG. 1  with the flip portion in the open state and positioned at a first location along the perimeter of main base. 
         FIG. 4  shows the wireless communications device of  FIG. 1  with the flip portion in the open state and positioned at a second location along the perimeter of main base. 
         FIG. 5  shows the wireless communications device of  FIG. 4  with the flip portion rotated to a new orientation. 
     
    
    
     DETAILED DESCRIPTION 
     One embodiment of a wireless communications device is shown in  FIG. 1 , and generally indicated at  10 . The wireless communications device includes main base  20 , a cover or “flip” portion  60 , and a hinge mechanism  100 . The base  20  includes a case or shell  22  that houses appropriate electronics, such as communications electronics  12 . In general, the case  22  includes a top or face  30 , a bottom  40 , and a sidewall  24  interconnecting the two. The face  30  includes user input means, such as keypad  32 , selection buttons  36 , and/or microphone  34 . While keypad  32  is shown as a conventional twelve-key keypad, the keypad  32  may take other forms known in the art, such as qwerty keypad. Further, while selection keys  36  are shown in an illustrative arrangement, other arrangements may alternatively be used. The bottom  40  is spaced from top  30  by sidewall  24  to form a cavity  42 . The cavity  42  advantageously houses appropriate communications and control electronics  12 , the details of which are not important to understanding the present invention. As can be seen in  FIG. 2 , the sidewall  24  includes a slot  26  that extends approximately 90° circumferentially around the perimeter  50  of case  22 . A flange  28  defines the lower edge of slot  24 , and top  30  helps define the upper edge of slot  24 . As shown, the underside of top  30  may include a guide protrusion if desired. The overall shape of case  22  in this illustrative embodiment is generally oval (in front view), with a major or longitudinal axis  52  and a minor or transverse axis  54 . For ease of reference, a midpoint  53  is located midway along major axis  52 , and is considered the center of main base  20 . Of course, the base  20  may take a shape other than oval, but a generally oval shape is believed advantageous for implementing the present invention. 
     The flip portion  60  likewise includes a case or shell  62  and advantageously has an overall shape (in front view) similar, or identical, to the main base  20 . As such, the flip portion  60  likewise is generally oval, with a major or longitudinal axis  92  and a minor or transverse axis  94 . As above, the center  93  of the flip portion&#39;s case  62  is defined as the midpoint of major axis  92 . Of course, the flip portion  60  may take a shape other than oval, but a generally oval shape is believed advantageous for implementing the present invention. In general, the case  62  includes a face section  70 , a top  80 , and a sidewall  64  interconnecting the two. For case  62 , the face section  72  is the portion of case  62  facing the main base  20  when the wireless communications device  10  is closed. The face section  70  includes output means, such as display  72  and/or speaker  74 . The top  80  is spaced from face section  70  by sidewall  64  to form a cavity  82 . The cavity  82  advantageously houses appropriate electronics  14 , such as an antenna, communications electronics, and/or control electronics, or the like, the details of which are not important to understanding the present invention. As can be seen in  FIG. 2 , the sidewall  64  includes a slot  66  defined between face portion  70  and flange  68 . The slot  66  advantageously extends approximately 90° circumferentially around the perimeter  90  of case  62 . 
     The flip portion  60  is moveably coupled to the main base  20  by hinge mechanism  100 . Hinge mechanism  100  includes a primary carriage assembly  110  pivotally coupled to a secondary carriage assembly  120 . The primary carriage assembly  110  is associated with main base  20  and includes a hinge plate  112  with a flange  114  on one end, a hook portion  116  on the other end, and a central section  118  disposed therebetween. The central section  118  is disposed in slot  26 , and flange  114  extends outward from slot  26 . Hook portion  116  extends inwardly so as to wrap around flange  28  in order to maintain hinge plate  112  associated with main base  20 . As can be seen in  FIG. 2 , flange  114  advantageously extends out from slot  26  at an upward angle. Primary carriage assembly  110  advantageously includes suitable means for reducing sliding friction between hinge plate  112  and case  22 . For example, primary carriage assembly  110  may include one or more spheres  119  that rollingly support hinge plate  112  against flange  28 . With such an arrangement, it may be advantageous for flange  28  to include some shallow detent recesses (not shown) that face hinge plate  112 , so that primary carriage assembly  110  may be preferentially located in predetermined locations along slot  26  relative to perimeter  50 . 
     The secondary carriage assembly  120  is associated with the flip portion  60  and includes a hinge plate  122  with a flange  124  on one end, a hook portion  126  on the other end, and a central section  128  disposed therebetween. The central section  128  is disposed in slot  66 , and flange  124  extends outward from slot  66 . Hook portion  126  extends inwardly so as to wrap around flange  68  in order to maintain hinge plate  122  associated with flip portion  60 . Secondary carriage assembly  120  also advantageously includes suitable means for reducing sliding friction between hinge plate  122  and case  62 . For example, sphere(s)  129  may form a rolling sphere(s) arrangement similar to that discussed above. Further, detents (not shown) may be used so that secondary carriage assembly  120  may be preferentially located in predetermined locations along slot  66  relative to perimeter  90  of case  62 . 
     A hinge joint  130  connects hinge plate  112  to hinge plate  122  so that flip  60  may be opened and closed. The hinge joint  130  may take any suitable form known in the art, such as a dampened or detented hinge connection. The hinge joint  130  allows flip portion  60  to be moved between a closed state and an open state relative to main base  20  by rotation about pivot axis  132 . In the closed state ( FIG. 1 ), the flip portion  60  overlies the main base  20 , such that face  70  faces face  30 . In the open state ( FIG. 2 ), flip portion  60  is rotated about hinge axis  132  so that a non-zero included angle Θ is formed between faces  30 , 70 . This included angle Θ is advantageously in the range of 90°-180°. 
     As can be appreciated, primary carriage assembly  110  slides along slot  26  so as to be moveable along the perimeter  50  of main base  20 . This sliding motion allows the flip portion  60  to be moved from a first position ( FIG. 3 ) to a second position ( FIG. 5 ) along perimeter  50 , while flip portion  60  is in the open position, and advantageously while angle Θ is held constant. For example, the first perimeter position may correspond to a conventional flip-phone configuration ( FIG. 3 ), where the major axis  92  of flip portion  60  is parallel to, or advantageously coincident with, the major axis  52  of main base  20 . When positioned in this manner, there is a maximum distance between the speaker  74  and microphone  34 , and the device  10  may be easily used as a conventional cell phone. The flip portion  60  may be moved relative to the main base  20  to a second position, such as one more suitable for gaming or business software functions. To do so, the primary carriage assembly  110  of hinge mechanism  100  is slid along slot  26 , with the length of slot  26  helping determine the allowed amount of sliding. For example, if slot  26  extends for a 90° arc, then hinge mechanism  100  is limited to 90° of movement relative to the center  53  of main base  20 . When moved as described, the major axis  92  of flip portion  60  is moved from being parallel to main base major axis  52  to being perpendicular thereto. Thus, the overall device would have a T-shape as depicted in  FIG. 4 . However, secondary carriage assembly  120  is also slidable along slot  66  so as to be moveable along the perimeter  90  of flip portion  60 . Assuming that slot  66  also sweeps a 90° arc, the resulting dual sliding action allows flip portion  60  to be rotated into a new orientation so that the respective major axes  52 , 92  are again parallel, although not coincident. See  FIG. 5 . This arrangement is believed advantageous when using the device  10  for gaming or business applications. 
     As can be seen, the movement of the flip portion  60  from the position shown in  FIG. 3  to the position shown in  FIGS. 4-5  has the effect of changing the orientation of a theoretical line  99  extending from the center  53  of main base  20  to the closest point on the perimeter  90  of flip portion  60 . This line  53  thus changes its relative angle β with respect to major axis  52  as the flip portion  60  is moved. Further, if the hinge mechanism  100  also slides along slot  66  in flip portion  60 , then points of closest approach on the perimeter  50  of main base  20  and the perimeter  90  of flip portion  60  change from X and X′ to Y and Y′, respectively. 
     While the above description has been in terms of the device  10  changing configuration from the “in-line” configuration of  FIG. 3 , to the T-shaped configuration of  FIG. 4 , to the “side by side” configuration of  FIG. 5 , the transformation may be in the reverse sequence. Further, the flip portion  60  may simultaneously be moved relative to main base  20  and “spun” relative thereto, so that movement steps are combined and the interim T-shaped configuration of  FIG. 4  is avoided. 
     In some embodiments, the main base  20  and/or flip portion  60  may include appropriate sensors  16  for detecting the relative orientations and positions of the components. And, based on these sensors  16 , the wireless communications device  10  may change its operational mode. For example, with the wireless communications device  10  disposed as shown in  FIG. 3 , the control electronics may “orient” the display  72  “vertically” such that the point closest to speaker  74  is the functional “top” of the display  72 ; but when the wireless communications device  10  changes to the arrangement shown in  FIG. 5 , the control electronics may “orient” the display  72  “horizontally” so that the point closest to the speaker  74  is the functional “left” of display  72 . Similarly, the function of the selection buttons  36  may change. Indeed, if the keypad  32  is of a touchscreen type, then the layout of keypad  32  may also be adapted based on the geometrical relationship between the flip portion  60  and the main base  20 . 
     The discussion above has assumed that the cases  22 , 62  are generally oval in shape; however, such is not required in all embodiments. Instead, the cases  22 , 62  may have any suitable shape, including generally rectangular, or the like, as is desired. 
     Further, there are typically conductor based electrical connections between main base  20  and flip portion  60 , such as for carrying display information to display  72 , or audio output signals to speaker  74 . As such, hinge mechanism  100  may advantageously include appropriate contact rings and contacts (not shown), or other means, to allow electrical connections to be maintained despite the changing relative positions and orientations of main base  20  and flip portion  60 . And, any known approach, such as ribbon cabling, may be used to extend the desired electrical path(s) to and/or through hinge mechanism  100  from the electronics  12 , 14 . If ribbon cable or the like is used, then care should be taken so that sufficient length of cabling is provided so as to not impede the desired movements of the hinge mechanism  100 . 
     The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. Further, the various aspects of the disclosed device and method may be used alone or in any combination, as is desired. The disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Summary:
A wireless communications device, such as a cellular telephone, includes first and second bodies having respective perimeters. A display is associated with one of the bodies and user input is associated with the other. A hinge mechanism moveably couples the bodies together so that the second body may pivot between a closed state and an open state. The second body, while in the open state, is slidable from a first open position to a second open position along the perimeter of the first body. The first and second bodies may have respective major axes, and the major axes may be substantially parallel when the second body is in the first open position. The major axes may advantageously also be substantially parallel when the second body is in the second open position. The bodies may include respective peripheral slots along which the hinge mechanism moves.