Abstract:
A digital wrist watch includes a flexible digital display having an axis of curvature around which the display bends that is electrically connected to a microcontroller unit and is also electrically connected to a power source. Some of the plurality of electrical connections are positioned over at least one of a plurality of links that are configured to restrict twisting of the flexible digital display. The power source includes a battery positioned in an opening defined by one of the plurality of links The battery at least partially overlaps the plane of that link, The flexible digital display is selected from the group consisting of an electrophoretic display, a liquid crystal display, or an organic light emitting diode display.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/338,295 entitled “Mobile Device With Flexible Display” filed 17 Feb. 2010, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Mobile devices today ranging from cellphones, laptops, ebooks and ereaders, to digital watches all require an information display of some type to display text, graphics, or pictures. Liquid crystal displays were one of the first displays used in mobile devices and watches. Liquid crystal displays (LCDs) were initially developed in the 1970s. Due to tow power consumption. LCDs have since become the predominant display technology used in mobile devices. A LCD typically includes a layer of molecules aligned between two transparent electrodes, and two polarizing filters, the axes of transmission of which are (in most of the cases) perpendicular to each other. The liquid crystal molecules rotate when in the presence of an electric field and can be designed to enable light to either pass through the two polarizing filters or be blocked when an electric field is applied, 
         [0003]    In the 1990s several companies began to commercialize electrophoretic display technologies. Electrophoretic displays comprise some charged particle of particular color typically placed in a display with some liquid of contrasting color. When a voltage is applied across the two plates, the particles will migrate electrophoretically to the plate bearing the opposite charge from that on the particles. When the particles are located at the front (viewing) side of the display, it appears white when using white particles such as titanium dioxide. This is because light is scattered back to the viewer by the high-index titanium particles. When the particles are located at the rear side of the display, it appears dark, because the incident light is absorbed by the colored dye. The notable advantage of electrophoretic display technology is that it is reflective, and therefore is arguably more readable than other display technologies. Electrophoretic display technology is also bi-stable so that particles remain in their desired position without any charge, which can be a major power consumption reduction for displays that may have a lengthy duty cycle. A more recent display technology to emerge commercially is the emissive organic light emitting diode (OLED) displays. An OLED is a light-emitting diode (LED) whose emissive electroluminescein layer is composed of a film of organic compounds. This layer of organic semiconductor material is formed between two electrodes, where at least one of the electrodes is transparent. 
         [0004]    The typical flexible electrophoretic. LCD, or OLED display comprises two plastic substrates containing the chemical components that enable the display technology. These plastic substrates can be flexible. However, there typically remain significant limitations to the degree of flexibility or radius of curvature to which the product can be subject. Exceeding that flexibility or twisting the display may, for example, weaken the sealant used to hold these two outer plastic substrates together. 
       SUMMARY OF THE INVENTION 
       [0005]    This invention relates to mobile devices such as mobile phones, mobile computers, and timepieces (in particular wrist watches and other personal and/or wearable timepieces) that preferably include thin and/or flexible product designs. Various embodiments include integrated construction components and/or overall package designed to reduce twisting, and in some instances to also limit flexibility within the limits of the various flexible display technologies. The various embodiments described herein are preferably for use in applications such as watches, clocks, other timepieces, jewelry, mobile computers, and mobile phones. However, it should be understood that other portable consumer products are contemplated as within the scope of the invention. 
         [0006]    In one embodiment there is a watch comprising a flexible digital display capable of displaying at least one of chronological, graphical, or data information. The watch further includes at least one microcontroller unit (M CU) electrically connected to the flexible display. There is also a power source electrically connected to the flexible display. The watch further comprises means for reducing twist of the flexible digital display, wherein the means for reducing twist is positioned beneath and at least partially overlaps the flexible digital display. 
         [0007]    In another embodiment there is a watch comprising a flexible digital display capable of displaying at least one of chronological, graphical, or data information. The watch further includes at least one microcontroller unit (MCU) electrically connected to the flexible display. A power source is electrically connected to the flexible display. At least a portion of the flexible digital display spatially overlaps a means for permitting flex in a first axis and limiting flex in a second axis different from the first axis. 
         [0008]    In another embodiment there is a digital wrist watch including a flexible display having an axis of curvature around which the display bends. The flexible display is electrically connected to a microcontroller unit and is also electrically connected to a power source. At least some of a plurality of electrical connections are positioned over at least one of a plurality of links that are configured to restrict twisting of the flexible digital display. 
         [0009]    In another embodiment there is a timepiece comprising a flexible display positioned substantially within a polymer casing. The casing also encloses at least a portion of a means for restricting twist of the flexible display. A display face of the flexible display is adjacent to a substantially transparent portion of the casing. The flexible display is electrically connected to a power source and to controlling electronics for causing the display to present temporal information. 
         [0010]    In another embodiment there is a timepiece comprising a twist resistant spine. The spine spatially overlaps at least some of a plurality of electrical connections between MCU, a PCB, and a flexible display capable of displaying temporal information. The spine includes a main link and a plurality of additional links. The main link defines an opening for receiving a battery positioned therein. Alternatively, one or more of the links define an opening for receiving a battery or batteries positioned therein. 
         [0011]    In another embodiment there is a timepiece comprising a transparent layer above a flexible display bendable substantially in only a single axis. The timepiece includes a means for limiting flex to a single axis. The flexible display and a battery and a MCU and driving electronics and a PCB are all electrically connected together for causing the flexible display to present temporal information. 
         [0012]    In another embodiment there is a watch module comprising a spine for permitting limited flex in a first axis and restricting twist in other axis. The spine spatially overlaps a flexible display electrically connected to a microcontroller and driving electronics that are electrically connected to a flexible PCB. The spine comprises a plurality of links. Adjacent links are interconnected to permit only limited flex in the first axis. 
         [0013]    Multiple embodiments are disclosed and/or claimed herein. The variations or refinements described herein are generally applicable to most, if not all, of these embodiments. Such variations and refinement include the following individual refinements, as well as numerous combinations of these individual refinements. 
         [0014]    In one refinement the means for restricting twist, or the means for limiting flex to a single axis, or means for permitting flex in a first axis and limiting twist in a second axis different from the first axis, or means for permitting flex in a first axis and limiting flex in a second axis different from the first axis, includes a plurality of links. 
         [0015]    In another refinement the plurality of links includes a main link that is larger than at least one of the other links. 
         [0016]    In another refinement a link, preferably the main link, defines an opening for a battery, preferably a coin cell battery. 
         [0017]    In another refinement the battery at least partially overlaps the plane of the 
         [0018]    In another refinement at least one of the links includes rounded edges. In another refinement at least one of the links includes a stop to preclude flexing past a predetermined angle. 
         [0019]    In another refinement the majority of the links are smaller than the main link. In another refinement all of the links are smaller than the main link. 
         [0020]    In another refinement the plurality of links includes two smaller links adjacent to the main link, and each of the two smaller links includes a battery that is electrically connected to at least one of the MCU and the driving electronics. 
         [0021]    In another refinement the end link of the plurality of links includes an opening sized to mate with a protrusion from the module containing the display and associated controlling electronics. 
         [0022]    In another refinement at least two of the MCU, PCB and driving electronics spatially overlap one or more of the links. 
         [0023]    In another refinement each individual link does not flex. 
         [0024]    In another refinement the means for restricting twist, or the means for limiting flex to a single axis, or means for permitting flex in a first axis and limiting twist in a second axis different from the first axis, or means for permitting flex in a first axis and limiting flex in a second axis different from the first axis, is a sheet. The sheet material is selected from the group consisting of plastic or metal. 
         [0025]    In another refinement the sheet includes additional support segments to reduce twist. 
         [0026]    In another refinement the means for restricting twist, or the means for limiting flex to a single axis, or means for permitting flex in a first axis and limiting twist in a second axis different from the first axis, or means for permitting flex in a first axis and limiting flex in a second axis different from the first axis, includes a plurality of non-flexible supports integrated within a case material. 
         [0027]    In another refinement there is an outer casing constructed as a sleeve with at least one opening into which a module that includes the flexible display and the MCU is inserted. 
         [0028]    In another refinement the linkage assembly is secured directly to an internal portion of the casing to hold the module in place. 
         [0029]    In another refinement the protrusions are on an internal portion of the outer casing and interface with the buttons located in the strap portion of the outer casing. 
         [0030]    In another refinement the one or more electrical connections are positioned over a non-flexible portion of the means for restricting twist, or the means for limiting flex to a single axis, or means for permitting flex in a first axis and limiting twist in a second axis different from the first axis, or means for permitting flex in a first axis and limiting flex in a second axis different from the first axis. 
         [0031]    In another refinement the flexible display is selected from the group consisting of and electrophoretic display, a liquid crystal display, or an organic light emitting diode display. 
         [0032]    In another refinement the flexible display is an electrophoretic display. 
         [0033]    In another refinement the flexible display includes a frontlight having at least one light emitting diode. 
         [0034]    In another refinement the flexible display is an organic tight emitting diode display. 
         [0035]    In another refinement the flexible display is a liquid crystal display. 
         [0036]    In another refinement the transparent layer is silicone. 
         [0037]    In another refinement the casing is silicone. 
         [0038]    In another refinement the transparent layer and/or the casing is polyurethane. 
         [0039]    In another refinement the casing is leather and the transparent layer is silicone. 
         [0040]    In another refinement the casing is a flexible metal. 
         [0041]    In another refinement the links include polyphenylene sulfide. 
         [0042]    In another refinement the casing includes a magnet near an end of a strap portion of the casing, the magnet being within a protrusion from a surface of the casing, the cross-section of the protrusion being approximately the same as each of a plurality of sizing openings that begin near another end of the strap and are spaced apart toward the flexible display. 
         [0043]    In another refinement the sizing openings include material possessing some magnetic attraction. 
         [0044]    In another refinement there is screen printing on a east a portion of the strap portion of the casing. 
         [0045]    In another refinement the screen printing is of a substantially transparent gloss. 
         [0046]    In another refinement the substantially transparent gloss is present on a majority of the surface area of the casing. 
         [0047]    In another refinement a brand or logo is screen printed on the casing. 
         [0048]    In another refinement a brand or logo is screen printed to overlap at least a portion of the flexible display. 
         [0049]    In another refinement a strap portion of the casing includes laser etching. 
         [0050]    In another refinement the casing includes two leather straps bound together. 
         [0051]    In another refinement the two leather straps are sewn together. 
         [0052]    In another refinement the at least one of the bottom of the transparent layer and the top of the flexible display includes a matte finish. 
         [0053]    In another refinement the at least one of the bottom of the transparent layer and the top of the flexible display includes a coating to minimize the formation of air pockets. 
         [0054]    In another refinement the bottom of the transparent layer includes a matte finish and further includes a coating to minimize the formation of air pockets. 
         [0055]    In another refinement the power source is a coin cell battery. 
         [0056]    In another refinement the coin cell battery is positioned in an opening in one of the links, preferably the main link. 
         [0057]    In another refinement there is further included a padding layer. 
         [0058]    In another refinement the padding layer is positioned between at least a portion of the flexible display and the PCB. 
         [0059]    In another refinement the MCU a driving electronics are bonded onto a flexible printed circuit board. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0060]      FIG. 1  is a cross sectional view of an embodiment of a flexible device. 
           [0061]      FIG. 2  illustrates aspects of a side cross-sectional view of a non-bendable portion of an embodiment in which a microcontroller or driving electronics could be positioned. 
           [0062]      FIG. 3  is a top view of a battery positioned at least partially within the means for restricting twist integrated in a flexible digital watch embodiment. 
           [0063]      FIG. 4  is a cross sectional view of an embodiment with a battery co-located in the same axis as the twist reduction link. 
           [0064]      FIG. 5A  is a view of an assemblage of links that provide a bendable structure while restricting twist. 
           [0065]      FIG. 5B  is a bottom perspective view illustrating a stop mechanism integrated within links. 
           [0066]      FIG. 6  is a side view of aspects of a structure of another embodiment of a means to restrict twisting. 
           [0067]      FIG. 7  is a cross-sectional view of an embodiment of a flexible watch assembly. 
           [0068]      FIGS. 8A-8C  are side, bottom, and top views, respectively illustrating various features of one embodiment of a flexible digital watch, 
           [0069]      FIG. 9A  illustrates a top view of the overall finished appearance of an embodiment of a flexible digital watch, 
           [0070]      FIG. 9B  illustrates a bottom view of the overall finished appearance of an embodiment of a flexible digital watch. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0071]    For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
         [0072]    The emergence of flexible display technologies (including electrophoretic displays, LCDs, and OLED displays) now enables the possibility of new designs and aesthetic features for mobile products. Many mobile products comprise a display, power supply (typically a battery), and user interface, at least some of which are positioned partially within and/or part of a case. Such products can be transformed via implementation of various flexible display technologies for mass production. Current flexible display technologies have significant limitations that impact their reliability. One such limitation is that two plastic substrates may be able to flex in one axis to a certain radius of curvature. However, the substrates are much more limited in other axis. For example, twisting or torsion forces can cause significant shearing stresses between adhesive layers that can cause de-lamination leading to display failures. One solution would be the use of plastics that are so thin and ultra-flexible with such a low durometer that these stresses would not be an issue. However, production of any of these display technologies using a non-rigid plastic is extremely difficult. 
         [0073]      FIG. 1  illustrates aspects of a mobile device  1002  having a flexible display. A first outer transparent layer  1001  encases at least a portion of the flexible display  1003 . Those of ordinary skill in the art will understand that referring to layer  1001  as transparent means that the majority of the surface area of one side of the layer  1001  is transparent. Layer  1001  is considered transparent even if portions of it are opaque or translucent, or if portions are covered by an opaque top casing. Positioned behind the transparent layer  1001  is the flexible display  1003 . Examples of a flexible display  1003  include, but are not limited to, electrophoretic displays, LCDs, and OLED displays. Located within the mobile device  1002  between the transparent layer  1001  and the back casing  1004  is a means for substantially restricting (preferably severely reducing and even more preferably eliminating) twist in other than the flexing axis. 
         [0074]    In many mobile devices, particularly watches, there is typically spacing between the top transparent layer  1001  and an underlying display. This spacing is present because the displays are typically constructed out of glass and are subject to breakage should significant pressure be applied to an outer surface (that can flex and apply pressure and possibly break the underlying glass display). In a flexible mobile device  1002  (in particular a watch) subject to flexing it is preferable to have minimal empty spaces, and even more preferable to have no empty spaces. Minimal to zero spacing is preferably present between the flexible display  1003  and outer transparent layer  1001 . To permit flex in the mobile device or watch  1002  both the layer  1001  and other casing materials should be constructed from a flexible material. Such flexible materials include, but are not limited to, silicone, soft plastics, or rubbers. 
         [0075]    Layer  1001  preferably contacts the top surface of the flexible display  1003 . Since both are preferably made of soft and/or flexible materials, air pockets might be visible between the two layers (sometimes described as the watermark effect). Visible air pockets are not desired, and a special coating is preferably applied to at least one, if not both, of the bottom surface of the layer  1001  or the top surface of flexible display  1001  The coating adds some diffuseness to optical clarity as it typically includes tiny materials or particles acting as micro spacers between the two layers to prevent the formation of air pockets visible when the two surfaces are in contact. In another refinement the bottom surface of the layer  1001  has a matte finish that, when in contact with the top of the flexible display  1003 , assists in minimizing or preventing the formation of air pockets. 
         [0076]    Twist reduction mechanism  1011  preferably permits flexing of the flexible display  1003  (and mobile device  1002 ) substantially in only one axis. As used herein, twist reduction or restriction refers to permitting flexing or bending in a single axis (and in some embodiments limiting the amount of flexing on that single axis), but allowing zero to an insignificant amount of flexing in any other axis. Twist reduction mechanism  1011  preferably significantly reduces, and even more preferably substantially prevents, one or more modes of twisting of the mobile device  1002  that could result in failure of the flexible display  1003 . In one embodiment the means for reducing twist  1011  includes a linkage design. The twist reduction mechanism  1011  preferably includes a linkage design that can be customized to significantly limit twisting, The twist reduction mechanism  1011  even more preferably also includes a construction of the links designed to also allow a limited amount of flexibility in the preferred axis of flexibility, The twist reduction mechanism  1011  can comprise links constructed out of metals, or plastics. In one preferred embodiment the links are manufactured from hard plastics such as polyphenylene sulfide (PPS). Other embodiments of twist reduction  1011  mechanisms are contemplated as within the scope of the present invention. One example is a flexible plastic, but with cross sectional supports to reduce and/or prevent twistability. Another example is a frame construction that is hinged and allows flexing or bending only in one axis and only within the limitations of the flexible display  1003 . 
         [0077]    In consumer products ranging from mobile phones to wrist watches there are two other required components (not illustrated in  FIG. 1 ). First, a power source that typically includes a battery, preferably and most commonly a coin cell battery in watch applications, The power source could include a solar cell, preferably a solar cell connected to a battery (that consequently does not need to be a replaceable and/or removable battery). Second, the electronics comprising at least one microcontroller and supporting driving electronics. Any portion of the MCU or controlling electronics that would lie within the same cross section of the flexible display  1003  would likely be integrated on a flexible printed circuit board (PCB). In one variation the controlling electronics could reside in a cut-out within the twist reduction mechanism  1011  as well. 
         [0078]      FIG. 2  illustrates another embodiment in which a portion of a product is flexible. Various consumer products typically include at least one microcontroller unit (MCU)  2007 , and often multiple electronic components. Discrete components such as resistors and capacitors can be placed onto a flexible printed circuit board (PCB)  2006  and be subjected to some flexing. Such discrete components are connected to a small region and generally only include two contact points. However, problems can arise with respect to more complex electronics such as MCUs  2007 , and other driving components bonded to a flexible PCB  2006  that is then subjected to significant flexing. 
         [0079]    Excessive flexing or bending can often cause failure of the bonding (such failure resulting in loss of one or more connections). For complex electronics (MCU  2007  or display driver) there might be dozens to hundreds of connections made to the flexible PCB  2006 . Consequently, the portion including complex electronics is preferably first connected to flexible PCB  2006 , and located over a non-bendable link  2005  of the twist reduction mechanism. Depending on size, the MCU  2007  for other complex electronics) can be positioned over a link  2005  that might differ in size and shape from the neighboring individual links to limit flexing. The product might also include an integrated circuit (IC) upper guard  2008  as well as an IC lower guard  2009  (see  FIG. 2 ). Each of the guards  2008  and  2009  might be some type of PCB stiffener materials. The IC guard materials serve to protect MCU  2007  and restrict or prevent any flexing, particularly in regions that could result in loss of one or more connections. 
         [0080]    Referring to  FIG. 3 , there is a battery  3010  in a flexible wrist watch or other mobile device. Battery  3010  is a coin cell battery  3010 , it being understood that other types of power sources or other shaped battery  3010  might be used.  FIG. 3  illustrates a twist reduction assembly  3011  and individual links  3005 . Battery  3010  preferably overlaps a link  3012  that is larger than other links  3005 . A single larger link  3012  among smaller links  3005  provides for the possibility of improved consumer or aesthetic appeal. For example, it might permit a thinner mobile device, while at the same time providing a twist reduction assembly integrated within the mobile device. Alternatively, improved customer perceptions of flexibility might result from providing two or more smaller batteries. Smaller batteries positioned in separate links  3005  with link  3012  hinged between them would result in increased flexibility. 
         [0081]      FIG. 4  illustrates a battery  4010  co-located in the same plane as a main twist reduction link  4012 . Linkage  4012  having adjacent thereto links  4005 , that are smaller in at least one dimension to permit increased flexibility. Outer case  4004  includes a transparent outer layer  4001  positioned above the flexible display  4003 . Referring to layer  4001  as transparent again implies that the majority of the surface area of the layer is transparent. Layer  4001  is considered transparent even if portions of it are opaque or translucent, or if portions are covered by an opaque top casing. Examples of a flexible display  4003  include, but are not limited to, electrophoretic displays, LCDs, and OLED displays. For display types such as a LCD a backlight might typically be used. For a reflective display technology such as electrophoretic a front light is preferably used. Frontlights or backlights are part of the flexible display assembly  4003  as preferred, 
         [0082]    Referring to  FIG. 4 , flexible PCB  4006  is designated with cross-hatching, and beneath it is the means for restricting twist  4012  that overlaps the battery  4010 . Case back housing  4013  allows for access to the battery  4010  for replacement. A wrist watch preferably includes some level of water resistance ranging from splash resistant to 3ATM, 5ATM, or even as high as 10ATM. Transparent layer  4001  (preferably a transparent portion of the casing) and outer casing  4004 , and battery caseback  4013  are preferably designed to possess some level of water resistance. The controlling electronics and supporting electrical components are preferably, but not necessarily, located on the flexible PCB  4006  in the region beneath the flexible display  4003 . There is preferably further included a padding layer  4020 . Padding layer  4020  might be positioned either between the flexible display  4003  and flexible PCB  4006  layer as shown in  FIG. 4 , or between flexible PCB  4006  and means for reducing twist  4011 . Padding layer  4020  assists in protecting the display from stress applied during twisting or flexing of the device, and damage that could be caused to the display from the harder twist reduction mechanism  4011  pressing against it. Layer  4020  could be a thin soft material including, but not limited to, silicone, rubber or other low durometer materials. 
         [0083]    One embodiment including a means for restricting twist in a watch that must wrap around a wrist is the linked chain of  FIG. 5A . Individual links  5005  are connected. forming linkage assembly  5011 . Linkage assembly includes a larger central link  5012 . Main link  5012  includes an opening  5014  to permit a coin cell battery to be at least partially located within the same plane as the linkage assembly  5011 . Linkage assembly  5011  allows flexibility in one preferred axis to some degree, but significantly limits or prevents twisting in the other directions or axis of rotation. Linkage  5005  includes some interconnection  5015 , that might be a pin inserted through some portion of both of the adjacent links  5005 , thereby holding them together. 
         [0084]    A wide variety of connections between adjacent links  5005  are contemplated as within the scope of the invention. Such connections preferably permit some rotation and not a fixed, permanent orientation with respect to each other. For some applications it might be preferable to provide some flex in a single axis, but such flex not to exceed that beyond which the flexible display might fail over expected product lifetime. The individual link  5005  can be designed to allow the maximum amount of desired axis of flexibility that the flexible display can reliably tolerate repeatedly over product lifetime. In one refinement the design includes end links  5025 , that preferably include a taper. End link  5025  is constructed out of softer material than links  5005  and  5012 . End link  5025  also preferably includes an opening  5026  therein. Opening  5026  fits over a corresponding protrusion inside the main casing, This feature insures that linkage assembly  5011  does not float and/or shift within the assembled watch or device and it is held in place with respect to the overall outer casing. 
         [0085]    Referring to  FIG. 5B , the linkage assembly  5011  exhibits some rotation between each adjacent link  5005  in the portion that is bending or flexing in its single preferred axis. Links  5005  preferably include some degree of rounded edges. Rounded edges increase the amount of flexibility or bending of the wrist watch in the single desired bending axis. However, other embodiments are contemplated as within the scope of the invention using links  5005  that are less rounded on the edges where links interface. More squared off individual links  5005  reduce the amount of rotation. Additional design elements can also be integrated into the linkage assembly  5011  to reduce or prevent flexibility beyond the limitations of the internal components. Stops  5035  might also be included to prevent flexing in the preferred axis past some predetermined angle.  FIG. 5B  illustrates an enlarged view of the larger main link  5012  that includes opening  5014  for a battery (preferably positioned at least in part in the same plane). Link  5012  also preferably includes openings  5040  to fix linkage assembly  5011  to protrusions in the main casing or to the flexible PCB or flexible display. 
         [0086]      FIG. 6  illustrates aspects of another potential means for restricting twist in a flexible mobile device. A thin sheet of material  6030  is employed that can be constructed using any number of plastics or metals. At least one side of thin sheet  6030  includes geometric features or pattern  6035 . Features or pattern  6035  are either present as part of the construction of the thin sheet  6030 , or affixed to the thin sheet  6030 . The geometrical features are designed to limit the degree of flexibility in at least one axis. These features  6035  can also be designed to reduce twistability as well. 
         [0087]    Referring to  FIG. 7 , flexible digital watch  7002  includes an outer casing  7004 . At least a portion of casing  7004  is constructed out of a flexible material including but not limited to, various plastics, rubber or silicone, as well as flexible metal, or leather. Casing  7004  at least partially, and preferably entirely, encases the flexible display  7003 , a power source that is typically a battery  7010 , and controlling electronics on flexible PCB  7006 . Top transparent layer  7001  can be made of the same materials as the outer casing  7004  and produced in a single production procedure. Alternatively, top layer  7001  is a different material that is later bonded by heat or adhesive to the casing  7004 . For example, attaching a silicone transparent top layer  7001  to a leather or flexible metal casing  7004 . As with previously described embodiments, in one refinement a coating is applied to the bottom surface of the transparent top layer  7001  to prevent the formation of any air bubbles or “watermark” visible effects. At least partially within the casing  7004  is the module that includes flexible display  7003 , flexible PCB  7006 , and twist restriction linkage assembly  7012 . A padding layer could also be included, preferably inserted between the flexible display  7003  and the twist restriction linkage assembly  7012  to reduce the chances of damage to the flexible display  7003  during product life. Battery  7010  overlaps main link  7012 . Battery hatch  7013  can take many forms, but in  FIG. 7  the hatch  7013  is a piece of plastic or metal attached by screws  7023  to link  7012 . 
         [0088]    Referring to  FIGS. 8A-8C  there is a module for a flexible digital watch that includes linkage assembly  8011 , battery  8010 , and flexible display  8003 . As shown in  FIG. 8B  the battery  8010  preferably fits into main link  8012  that is slightly larger than individual links  8005 . To reduce the size of main link  8012  one could use batteries  8010  with a smaller diameter, or put two smaller diameter batteries  8010  side-by-side. Alternatively, one could put smaller diameter batteries  8010  on different smaller links  8012 .  FIG. 8C  illustrates one orientation of a flexible display  8003  on a portion of linkage assembly  8011 . The linkage assembly  8011  reduces the twisting to which the flexible display  8003  can be subjected. Additionally, linkage assembly  8011  might also be designed to reduce the flexibility of the overall mobile device. 
         [0089]    Alternative mechanisms could be used instead of linkage assembly  8011 . Such mechanisms might comprise a plastic or metal sheet, or supports integrated as an underlying structure or within the outer casing (not shown in  FIG. 8 ).  FIGS. 8A-8C  also illustrate the preference to reduce the overall thickness of the watch in the regions where the flexible display  8003  is located. In some cases the outer casing (not shown in  FIG. 8 ) might taper down to be thinner in the strap area. When the outer casing is produced using compression and/or heat injection molding technique (using plastics or silicone to produce a sleeve with at least one opening) the tapered down area that does not contain a module might need to be filled with some material. End link  8025  might preferably comprise a flexible elastomer filler material ranging from plastic, silicone or flexible metal, and often tapers to a decreased thickness. End link  8025  is attached to linkage assembly  8011  and inserted into the outer casing in the strap region. 
         [0090]    Referring to  FIGS. 9A-9B , flexible watch  9002  includes a transparent top layer  9001  over a flexible digital display  9003 . Layer  9001  and display  9003  are at least partially surrounded by the outer casing  9004 . Water resistance is a standard feature in watches. Thus, flexible display  9003  and supporting electronics are preferably enclosed in a water tight case construction. Some products that incorporate new flexible display technologies and may only need some level of “splash.” water resistance can be constructed without the need for the top transparent layer  9001  over the flexible display  9003 . In such designs the top surface of the flexible display  9003  is external and accessible to touch. It is contemplated as within the scope of this invention that a flexible watch or mobile device as taught herein could also be constructed without the top transparent layer  9001 , and only include the outer casing  9004 . When transparent layer  9001  is not present over the flexible display  9003  there may be sealant applied around the outer casing  9004  along the window where the flexible display  9003  is visible. 
         [0091]    Referring to  FIGS. 9A-9B , the size of the flexible display relative to the watch is not necessarily to scale, and is only representational. That is to say, the flexible display  9003  as illustrated is only a small portion of the overall flexible watch  9002 . Economies of scale and other factors should drive the price of flexible displays downward and result in greater reliability when bent. As reliability improves and price decreases the flexible display  9003  and corresponding top transparent layer  901  might be increased in size and result in an even longer display in strap than is illustrated  FIGS. 9A-9B . Both the top transparent layer  9001  and outer casing  9004  can be constructed out of any variety of plastics, ranging from polyurethanes (PU) to silicones, or other flexible materials such as rubber, etc. In one variation the top transparent layer  9001  is a flexible plastic such as silicone or polyurethane, and is attached to a flexible outer casing  9004  material. Flexible outer casing material could be plastic, silicone, leather, or flexible metal. Examples of such metals include, but are not limited to, thin (preferably very thin) flexible metals such as aluminum or steel. 
         [0092]    Watches and other mobile devices often use one or more buttons or user interface components, such as membrane switches, or dome push buttons, or any number of existing implementations. Referring to  FIGS. 9A-9B , the buttons  9055  are placed within the flexible case construction in the strap region, Buttons  9055  include switches underlying the flexible outer casing  9004 . Small protrusions are preferably used on the outer casing  9004 , such protrusions being positioned to overlap the buttons  9055  located. on flexible PCB internally. Thus, pressure on the outer casing results in button press. However, optimization of the design is useful so that flexing of the watch does not result in pressure activation of the buttons  9055 . In another variation (not illustrated in  FIGS. 9A-9B ) the buttons  9055  could be located underneath the flexible display  9003 , and activated by pushing on the flexible display  9003  in that area of the button  9055  location. 
         [0093]    Various known watch closure mechanisms can be employed on a flexible digital watch to connect the straps together as they wrap around the wrist. Examples include, but are not limited to, standard buckle with holes in strap, butterfly closures, etc. The embodiments disclosed herein are preferably used with the magnetic closure mechanism discussed herein. Top surface of watch  9002  includes a logo plate  9070  that overlaps closure magnet  9075  protruding from the bottom side. Magnet  9075  is preferably a neodymium magnet. Top side of outer casing  9004  includes sizing holes  9080  located in the strap sizing region. Magnets or steel material are positioned beneath the sizing holes  9080 , preferably at least partially within outer casing  9004 . Flexible digital watch  9002  is wrapped around the wrist, and the protruding closure magnet  9075  is fitted into the appropriate sizing hole  9080 . The magnets or steel located beneath each sizing hole provides a magnetic attractive surface for retention. The sizing holes  9080  enable the protrusion of the closure magnet  9075  to fit therein, and provides additional holding strength so that shearing forces do not easily cause the band to come undone from the wearer. One or more magnets could be used on the closure magnet  9075  side or on sizing holes side  9080  of the strap to provide additional holding strength. 
         [0094]    Referring to  FIG. 9B , in one preferred embodiment the outer casing  9004 , preferably including a transparent portion that serves as top layer  9001 , is produced out of at least one mold using either silicone pressure mold or injection molding. This single outer casing  9004  portion has an opening where the module including the flexible display  9003 , controlling electronics on flexible PCB, and twist reduction mechanism is inserted. These components are bottom loaded and secured within and often connected directly to the inner portions of the outer casing  9004 . External patch  9085  is then adhered to the opening of the outer case  9004  seating the module therein and providing some level of water resistance, The patch can be secured to the outer casing by a variety of means, but preferably via adhesives. The battery is inserted and the battery cover  9013  is secured by screws to the main link. 
         [0095]    In another embodiment the production of the flexible watch  9002  includes an outer casing  9004  made out of silicone or polyurethane plastic produced by placing a dummy module into a mold, and the outer casing  9004  is then formed through compression or injection molding techniques after which the dummy module is then removed. Using this production technique the outer casing  9004  is effectively like a sleeve that can have either one or both ends open. The opening in the formed flexible outer casing  9004  is then used to insert the flexible watch module assembly. Then one or both ends of the outer casing  9004  can be sealed by heat, sealant, adhesive, or even a cap so that some level of water resistance can be achieved for the flexible wrist watch or mobile device. Additional areas within the plastic or silicone outer casing construction can also be added that would hold the display and the flexible PCB in place. On a watch that will be subjected to bending such permits the flexible display  9003  to stay in the correct position with the top transparent layer  9001 . Such also aids in insuring that the underlying flexible PCB does not bunch up in any area of the assembly, but remains in a fixed position after being inserted in the production process. 
         [0096]    Those of ordinary skill in the art will understand that a variety of flexible displays might be used in any embodiment of the present invention. Such flexible displays include any of a variety of technologies including, but not limited to, electrophoretic, liquid crystal, and OLED. Those of ordinary skill in the art will further understand that a front light or backlight could be used in conjunction with electrophoretic or liquid crystal displays, respectively, and such lighting is considered to be part of the flexible display assembly whenever illustrated in the figures herein. Prototypes of one embodiment have been made that include an electrophoretic display using segmented displays. However, other embodiments contemplated as within the scope of the invention include, but are not limited to, a matrix electrophoretic display, or matrix OLED display. 
         [0097]    A wide variety of shapes and sizes of flexible displays are contemplated as within the scope of the present invention. In one embodiment the display has a width of about 16 mm to 20 mm and a length of about 45 mm to 50 mm. It will be understood by those of ordinary skill in the art, however, that the display is not limited to rectangular shapes. For example, electrophoretic displays (E INK. displays) permit rounded or curved shapes. As another example, persons of smaller stature will typically prefer a watch display better sized for their arm and/or hand, and thus might prefer a watch with a smaller display. Similarly, watches marketed to males are often larger, and might include a larger display. 
         [0098]    As previously noted, some embodiments include a transparent layer that preferably contacts the top surface of the flexible display. Since both are preferably made of soft and/or flexible materials, air pockets might be visible between the two layers (sometimes described as the watermark effect). In all such embodiments visible air pockets are undesirable. To minimize the resulting “watermark effect” a special coating is preferably applied to at least one, if not both, of the bottom surface of the top layer or the top surface of flexible display. Such coating is preferably added to the bottom surface of the top layer. Another mechanism for addressing the “watermark” effect is providing a matte finish to at least one, if not both, of the bottom surface of the top layer or the top surface of the flexible display. Again, such matte finish is preferably added to the bottom surface of the top layer, it is also contemplated that both a matte finish and a coating could be provided. For ease of manufacture the matte finish and coating are preferably, but not necessarily, both on the same surface (again preferably the bottom surface of the top transparent layer). 
         [0099]    Some embodiments of the present invention preferably include a means for restricting twist integrated within the case of the mobile device or wrist watch, or within the outer case construction itself. These “integrated” embodiments aid in providing one or both of two outcomes. The first is to preferably insure that the portion of the product where the flexible display is located can not be subjected to twisting forces that would cause failure of the flexible display. The second is to preferably prevent the overall product and the display from flexing in the provided for axis of flexibility beyond the limitations or radius of curvature of the display. 
         [0100]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow, In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.