Abstract:
Slide-out and roil-up information displays and methods supply enlarged viewing areas. A slide-out information display device includes stacked display segments wherein each of the display segments except one is at least partially covered by the others. Separable bezel segments support the display segments, the stacked display segments being uncovered when the bezel segments are separated from a collapsed configuration to an un-collapsed configuration for use by a user. A roll-up display device includes flexible display membranes. Scrolling assemblies in the roll-up display include rotatably mounted scrolling assembly mechanisms for rolling up the flexible display membranes. Some scrolling assemblies are movable and can be extended beyond the housing members. At least one display membrane being covered by at least one other display membrane when the movable scrolling assemblies are not extended, and the covered display membranes being uncovered when the movable scrolling assemblies are extended.

Description:
INCORPORATION BY REFERENCE 
       [0001]    Each of the following U.S. patent applications and U.S. patents is incorporated in its entirety by reference herein: 
         [0002]    Pocket Computer with Full-Size Keyboard, U.S. Pat. No. 6,088,220, filed Oct. 2, 1997; 
         [0003]    Collapsible Display Device and Methods for Using the Same, U.S. patent application Ser. No. 10/719,300, filed Nov. 21, 2003; 
         [0004]    Continuously Displayable Scroll-Type Display, U.S. Pat. No. 6,498,597, filed Oct. 28, 1999; 
         [0005]    Mobile Terminal Device, Content Distribution System, Content Distribution Method, and Program for Executing Method Thereof, U.S. patent application Ser. No. 10/012,558, filed Dec. 12, 2001; 
         [0006]    Black/White Cholesteric Bistable Display with Increased White Reflectivity, U.S. patent application Ser. No. 11/004,752 filed Dec. 3, 2004; 
         [0007]    Electronic Apparatus With a Foldable Display, U.S. Pat. No. 5,734,513, filed Apr. 3, 1996; and 
         [0008]    Desktop Manager for Graphical User Interface Based System with Enhanced Desktop, U.S. Pat. No. 5,835,090, filed Oct. 17, 1996. 
     
    
     BACKGROUND 
       [0009]    Portable computing devices such as, e.g., personal digital assistants, display-enhanced cellular telephones, portable electronic document readers, and interactive electronic guidebooks are typically produced with displays that are limited in visual area because the portable computing devices are preferably designed to be conveniently carried in the human hand. This is particularly true where the display is integrated with the body of the portable electronic device. 
         [0010]    Accordingly, it would be desirable to provide a display that can be stored in a small space, but can be subsequently opened into a form that is much wider than the device to which it is attached. Preferably, an opened display for a portable device should be rigid enough that the user does not have to provide separate support for the display or set the portable device on a flat supporting surface. It would be additionally advantageous for the display to be easily opened with one hand since the other hand is usually used to support the portable computing device. 
         [0011]    There has been prior work on displays that can be expanded to a greater viewing area. For example,  FIG. 1  shows a known four-segment hinged display device  100  as described in U.S. Pat. No. 6,088,220 titled Pocket Computer with Full-Size Keyboard. Each half of the display  100 , as shown, has been folded out along a respective pair of horizontal hinge arrangements  120 - 180 . Hinged displays of this kind require repetitive manual actions to open or close the display, and generally involve flex cabling across each hinge arrangement which introduces additional potential failure points to the display. Further, this type of display arrangement multiplies the number of segment boundaries which results in visible seams in the display unless additional steps are taken. 
         [0012]    Published U.S. patent application Ser. No. 10/719,300, titled Collapsible Display Device and Methods for Using the Same, discloses a number of fold-up display geometries that use non-right-angle folds, twists and pivots to reduce the number of manual actions needed to open the display. For example,  FIG. 2  shows a display  200  which consists of a number of display segments  220  that open around a pivot  240 . Also disclosed are fold-up displays similar to folding fans, twist-up displays using spring-like exterior rings, pop-up displays that apply “pop-up book” techniques, and umbrella displays that apply a hub-spoke umbrella action. 
         [0013]    Roll-up displays utilizing flexible display materials have been proposed such as, e.g., the roll-up display  300  shown in  FIG. 3  and disclosed in U.S. Pat. No. 6,498,597 titled Continuously Displayable Scroll-Type Display. The roll-up display device  300  utilizes a scroll-like flexible display medium  320  which is stored in a cylindrical magazine  340 . A practical issue arises from using a flexible display material which is preferably viewed flat, and which is also sometimes fragile. 
         [0014]    One approach is to utilize an accordion-like support structure similar to the one disclosed in U.S. patent application Ser. No. 10/012,558 titled Mobile Terminal Device, Content Distribution System, Content Distribution Method, and Program for Executing Method Thereof. With reference to  FIG. 4 , the roll-up display device  400  includes an accordion-like supporting structure  420  for supporting the flexible display material  440 . Other roll-up displays use a “bamboo scroll” type of supporting structure which provides lateral support, but does not provide longitudinal support. It should be noted that, while the roll-up configuration has the advantage of expanding for use and collapsing to a smaller area for storage, the area to which it collapses is still limited in its degrees of freedom by its constant width, as is the area to which it expands. In other words, although the display area can be changed in its length dimension, its width dimension is generally fixed. 
         [0015]    Accordingly, it would be advantageous to introduce display configurations that overcome certain disadvantages of existing technologies. 
       BRIEF DESCRIPTION 
       [0016]    An expanding electronic display is provided which includes two display sections, one of the two display sections being configured to be hidden from view when the expanding electronic display is in a first position. A movement mechanism permits movement of one of the display sections into a relationship to the remaining display section which permits viewing of both display sections concurrently. 
         [0017]    A slide-out information display device is also provided which includes stacked display segments. Each of the display segments except one is at least partially covered by one or more of the remaining display segments. Bezel segments are provided for supporting the display segments, and are arranged such that the bezel segments are separable from each other in at least one direction, the stacked display segments being uncovered when the bezel segments are separated from a collapsed configuration to an un-collapsed configuration for use by a user. The uncovered display segments thereby provide an enlarged viewing area. 
         [0018]    A roll-up display device is also provided which includes flexible display membranes. A pair of scrolling assemblies is included, one of which includes a rotatably mounted scrolling assembly mechanism for rolling up a first flexible display membrane. Additional scrolling assemblies are also provided, one of which includes a second rotatably mounted scrolling assembly mechanism for rolling up a second flexible display membrane. The additional scrolling assemblies are movable in at least one direction and can be extended beyond the first pair of scrolling assemblies, the second display membrane being covered by the first display membrane when the additional scrolling assemblies are not extended, and the second display membrane being uncovered when the additional scrolling assemblies are extended, thereby providing an enlarged viewing area. 
         [0019]    A method is also provided for forming a slide-out information display. The method includes stacking display segments, each of the display segments except one of the plurality of display segments at least partially covered by one or more of the remaining display segments. The plurality of display segments are supported in at least two bezel segments, and the bezel segments are interconnected such that the bezel segments are separable in at least one direction. The covered stacked display segments are uncovered when the bezel segments are moved from a collapsed configuration to an un-collapsed configuration by a user, the uncovered display segments thereby providing an enlarged viewing area. 
         [0020]    A method is further provided for forming a roll-up display. The method includes providing a pair of scrolling assemblies, at least one scrolling assembly including a rotatably mounted scrolling assembly mechanism for rolling up a flexible display membrane. An additional pair of scrolling assemblies is provided, one of the additional scrolling assemblies including a second rotatably mounted scrolling assembly mechanism for rolling up a second flexible display membrane. The additional scrolling assemblies are movable in at least one direction and can be extended beyond the first pair of scrolling assemblies, the second display membrane being covered by the first display membrane when the additional scrolling assemblies are not extended, and the second display membrane being uncovered when the additional scrolling assemblies are extended by a user, thereby providing an enlarged viewing area. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a known four-segment hinged display device; 
           [0022]      FIG. 2  is a known display which consists of a number of display segments that open around a pivot; 
           [0023]      FIG. 3  is a known roll-up display; 
           [0024]      FIG. 4  is a known roll-up display including an accordion-like support structure; 
           [0025]      FIG. 5  is a first configuration for a slide-out information display; 
           [0026]      FIG. 6  is the first configuration for a slide-out information display shown in an operable, expanded configuration; 
           [0027]      FIG. 7  is a second configuration for a slide-out information display; 
           [0028]      FIG. 8  is the second configuration for a slide-out information display expanded for use; 
           [0029]      FIG. 9  is a third available configuration of a slide-out information display; 
           [0030]      FIG. 10  is a side view of the third available configuration of a slide-out information display; 
           [0031]      FIG. 11  is a fourth available configuration of a slide-out information display; 
           [0032]      FIG. 12  is a fifth available configuration of a slide-out information display; 
           [0033]      FIG. 13  is a first available configuration of a slide-out information display utilizing flexible display membranes; 
           [0034]      FIG. 14  is a top view of the information display of  FIG. 13 ; 
           [0035]      FIG. 15  is the information display of  FIG. 13  manually extended in the vertical direction; 
           [0036]      FIG. 16  is a second available configuration of a slide-out information display using flexible display membranes; 
           [0037]      FIG. 17  is a third available configuration of a slide-out information display utilizing flexible display membranes; 
           [0038]      FIG. 18  is a fourth available configuration of a slide-out information display utilizing flexible display membranes; 
           [0039]      FIG. 19  is a side view of the information display of  FIG. 18  in a collapsed position; and 
           [0040]      FIG. 20  is a side view of the information display of  FIG. 18  in an extended position. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    Referring now to  FIGS. 5-16 , slide-out information displays corresponding to concepts of the present application, and distinct from those discussed in connection with  FIGS. 1-4 , are more particularly described. 
         [0042]    With reference now to  FIG. 5 , a first configuration  500  for a slide-out information display is shown. The first configuration  500  is shown in a closed position. The slide-out information display includes a set of stacked display panels  502 ,  504  wherein the first display panel  502  is visible in the figure and the second display panel  504  is stacked beneath a first display panel and is not visible in the figure. The slide-out information display includes interconnected frame members or bezel segments  506 ,  508  for supporting the first and second display panels. The frame members in this embodiment are interconnected by an upper support member  510  and a lower support member  512  which reside in respective frame channels  514 ,  516  for maintaining the first and second frame members in proper relationship with respect to each other. It is to be understood that the connecting members  510 ,  512  residing in the respective channels  514 ,  516  are exemplary representations, and any suitable interconnecting arrangement as known in the art is included within the scope of the present disclosure. It is to be further understood that the display panels  502 ,  504  can be any rigid or semi-rigid type of display panel known in the art. Available components for the display panels will be readily apparent to one of skill in the art 
         [0043]    With reference now to  FIG. 6 , the slide-out information display  500  is shown in an operable, expanded configuration. In this configuration, the second display panel  504  is positioned to the right of first display panel  502  as viewed when observing the display panels as shown in the figure. However, because the second display panel  504  is housed directly below display panel  502 , there remains a slight offset between the planes of the two panels at the position designated by the boundary line indicated by the numeral  518 , although the effect of the small offset is preferably negligible. 
         [0044]    With reference now to  FIG. 7 , a second exemplary configuration is shown similar to the previously described configuration shown in  FIG. 6  which, however, eliminates the need for supporting elements  510 ,  512 . In this second configuration, a first bezel segment  520  is configured such that a second bezel segment  522  rides in a hollow channel region  524  of the first bezel segment. As shown now in  FIG. 8 , when the second configuration of the slide-out information display is expanded, a region of overlap designated by numeral  526  provides support for the second bezel segment  522 . In this second arrangement, as in the first arrangement, a slight offset remains at the boundary line designated by numeral  528 . 
         [0045]    With reference now to  FIG. 9 , a third available configuration of a slide-out information display is shown. This third configuration is like the configuration shown with reference to  FIG. 8 , however, guide rollers  530  have been added to each side of the second bezel segment  522  for supporting the second bezel segment. A first bezel segment  520  has, consequently, been provided with guide channels  532  for supporting the guide rollers  530 . With reference to  FIG. 10 , a side view of the third available configuration is shown in an expanded operable position. In the expanded configuration, the guide rollers  530  continue to provide support for the second bezel segment  522 . It is to be noted that, as in the previous configurations, a slight offset  534  remains. 
         [0046]    With reference now to  FIG. 11 , and continuing reference to  FIG. 10 , a fourth available configuration of the slide-out information display is shown which eliminates the undesirable offset  534  of the previous configuration. This fourth configuration is identical in all respects to the third configuration except that the guide channels  532  are provided with a curved portion  536  which causes the second bezel segment  522  to be elevated with respect to the first bezel segment  520  when expanded, thereby eliminating the undesirable offset  534 , aligning the display panel segments on the same plane. It is to be appreciated that other interconnecting arrangements for eliminating the undesirable offset are known in the art and are included within the scope of the present disclosure. 
         [0047]    With reference now to  FIG. 12 , a fifth available configuration of a slide-out information display is shown. It is an object of this configuration to provide the user with a slightly convex viewing arrangement of the first and second display panels  502 ,  504 . This arrangement is similar to the previously shown arrangements except that the guide channel  532  is configured at an angle  544  with respect to the first display panel  502  thereby providing a convex viewing arrangement when expanded to the operable position as shown in the figure. It is to be appreciated that this configuration may also be provided with a curved region  536  as shown in the previous arrangement to eliminate the undesirable offset between the first and second display channels  502 ,  504  when expanded to the operable position. 
         [0048]    With reference now to  FIG. 13 , a first available configuration of a slide-out information display  600  utilizing flexible display membranes is shown. The information display  600  includes a first flexible display membrane  602  and a second flexible display membrane  604  having the first display membrane positioned slightly in front of the second display membrane as shown or viewed in the figure. The first flexible display membrane  602  is stored in respective left and right scrolling assemblies  606 ,  608 . It is to be appreciated that, although two scrolling assemblies are shown in the figure, alternate embodiments may incorporate only one scrolling assembly, i.e., on other words, one end of the display membrane is fixed and scrolling occurs by the one scrolling assembly. The second flexible display membrane is similarly stored in left and right scrolling assemblies  610 ,  612  and alternate embodiments may also be configured utilizing only one scrolling assembly for the second flexible display membrane  604 . 
         [0049]    In order for the flexible display membranes  602 ,  604  to be operable, they must be sufficiently rigid so as to provide a constant display area, yet sufficiently flexible so as to allow individual sections of the display to be deformed by rolling onto the scrolling assembly mechanisms, where required. The membranes  602 ,  604  will generally be built upon a layer of material that constitutes a structural substrate for the other components of the display membrane. The material must have thermal characteristics (such as melting point) and chemical characteristics such that it will withstand the fabrication processes of the various components of the display membrane that are built on top of it. The structural substrate material must also have mechanical properties that are suitable to the kind of deformation required by the specific display embodiment. The membranes  602 ,  604  may accordingly include one or more structural substrate layers made of any of the following: a low elasticity material, such as a metal foil; and a high elasticity material, such as a plastic or polymer. 
         [0050]    In certain embodiments, the membranes  602 ,  604  may include control layer components and addressing circuitry for addressing the display pixels that form a visual display area along the display membranes  602 ,  604 . In conventional display systems, individual circuit elements used in the addressing circuitry are often not fabricated in a manner that is suited for building collapsible displays. For example, construction of active-matrix liquid-crystal displays (LCDs), such as those commonly used as personal computer monitors, typically involves a fabrication process for building thin-film transistor (TFTs) in which silicon is deposited on thin glass sheets. The glass has thermal and chemical characteristics that are desirable for that fabrication process, but the glass sheets are at best semi-rigid. As another example, commercial displays have been built using bi-stable dielectric twisting-ball (gyricon) display elements. Many of these displays have been direct-addressed using large-area copper pads on conventional printed circuit boards (PCBs); the copper pads are driven using off-board control logic. 
         [0051]    PCBs are inexpensive but are entirely rigid. However, several alternative display control technologies are available such that the individual circuit elements (1) are themselves reasonably flexible and (2) can be fabricated using processes suitable for use with flexible structural substrates. There are a variety of such technologies, such as: amorphous silicon transistors fabricated at low-temperature; polysilicon transistors fabricated at low-temperature; organic transistors; and hybrid organic/inorganic transistors. The ability to include transistor elements within a flexible control layer enables the use of active-matrix techniques, which are important if the display layer technology is not bi-stable (see below). Other available components for the control layer will be readily apparent to one of skill in the art. 
         [0052]    In further embodiments, the membranes  602 ,  604  may include display layer components for activating or deactivating an addressed pixel. The display layer elements must be built from materials that are flexible and can be fabricated on flexible substrates. If a control layer is present in the display, the display layer must be controlled by addressing circuit elements that are themselves flexible and can be fabricated on flexible substrates. However, the cholesteric liquid crystal display has attracted attention in recent years as an electronic paper (e-paper) type of display device. The cholesteric liquid crystal display is capable-of utilizing reflection from surrounding lights as a light source and has a storage property which can hold display contents after the supply voltage is turned off. Further, because an active matrix is not needed for driving the display, cholesteric liquid crystal display devices are capable of providing cost effective large-capacity displays, and may use a flexible substrate which is particularly suitable for e-paper. An example of such a display is described in U.S. patent application Ser. No. 11/004,752 titled Black/White Cholesteric Bistable Display with Increased White Reflectivity. Such display technologies are often colloquially described using names such as “electric paper,” “electronic paper,” or “electronic ink” as well as others. Of these technologies, those in which the display elements are bi-stable (hold their image without the application of additional power) are often advantageous in that (1) they facilitate the construction of electronic devices with lower power consumption and therefore longer battery life, and (2) they do not need active-matrix elements to maintain their image. Other available components for the display layer will be readily apparent to one of skill in the art. 
         [0053]    In any of the embodiments described below, each of the display membranes  602 ,  604  may be provided as a single continuous sheet, however, in use, the membranes are aligned to provide the appearance of a continuous display membrane. Various technologies may be provided to conceal, mask or hide otherwise visible edges of the sections within the display area where the membranes are adjacent. U.S. Pat. No. 5,734,513 describes one such technique that may be adapted. In addition to hardware-based edge concealment techniques, software-based techniques can be used to reduce the effect (as perceived by the end user) of having multiple display sections with visible edges between them. For example, U.S. Pat. No. 5,835,090 describes how the position of application windows in a graphic user interface (GUI) can be constrained to always be displayed entirely within one of several display sections if desired. 
         [0054]    Although various useful display membranes have been developed and continue to be improved, there have not been many attempts to provide such display membranes in configurations that allow the display to be expanded to larger areas and collapsed to smaller areas. In particular, there have not been proposed various display device geometries that would be useful for providing larger display areas in more than one dimension to portable electronic devices. Most flexible display membranes instead are proposed in the form of single panel displays, simple roll-up displays, aligned-axis fold-up panel displays, or multiple-axis fold-up panel displays, as discussed previously. 
         [0055]    The pair of scrolling assemblies  606 ,  608  associated with the first flexible display membrane  602  are fixedly mounted in respective housing members  614 ,  616 . In this configuration, however, the scrolling assemblies  610 ,  612  associated with the second flexible display membranes  604  are movably housed in respective channels  618 ,  620  formed within the housing members  614 ,  616 . While  FIG. 13  shows an approximate perspective view from the front of the information display  600  as viewed by a user,  FIG. 14  shows a top view of the information display including scrolling assembly mechanisms  622 - 628  and an expanding support  632 . It is to be appreciated that the first configuration of the information display utilizing flexible display membranes in  FIG. 13  is shown with the housing members  614 ,  616  extended in a horizontal direction as shown in the figures. When the information display is not in use, the housing members  614 ,  616  may be closed horizontally while the flexible display membrane  602 ,  604  are stored in the respective scrolling assemblies  606 - 612 . The scrolling assembly mechanism operation can be facilitated in some embodiments by a spring and cam mechanism such as, e.g., those used in window shades and projection screens as known in the art. The expanding support  632  is provided for supporting the display membranes when the housing members  614 ,  616  are extended, and is described in more detail below. 
         [0056]    With reference now to  FIG. 15 , the information display  600  is shown manually extended in the vertical direction with scrolling assemblies for the second flexible display membrane  604  extended in their respective channels  618 ,  620  in a vertical direction (more details on connection for vertical movement are set out in  FIGS. 18-20  and the associated discussion). In this embodiment, the scrolling assemblies  610 ,  612  are slidably mounted in the channels  618 ,  620  so that they can be manually extended or pulled in a direction essentially parallel to the plane of the display membranes. The scrolling assemblies  610 ,  612  may be mounted so that there is sufficient friction to support the scrolling assemblies in their extended and/or collapsed positions. Other suitable means for supporting the scrolling assemblies  610 ,  612  such as, e.g., by the use of catches or cams and detents may also be used in some embodiments. This configuration advantageously increases the viewing area in both the horizontal and vertical directions. It is generally desirable to also include a rigid or semi-rigid support assembly for the flexible display membranes of some kind. The previously mentioned expanding support assembly  632  can be support rods  510  as shown in  FIG. 6 , telescoping rods like those used, e.g., for antennas or any other mechanism that serves the function of guiding and supporting the expanding information display device and flexible display membranes. For example, an accordion style expanding support  632  is shown in  FIG. 15 . 
         [0057]    With reference now to  FIG. 16 , and continuing reference to  FIG. 15 , a second available configuration of a slide-out information display using flexible display membranes is shown. The slide-out display  630 , as before, includes first and second flexible display membranes  602 ,  604 . Also included is an expanding support assembly  632  and the scrolling assemblies  606 - 612 . While the previous embodiment shown in  FIG. 15  required manual extension of the scrolling assemblies  610 ,  612  in the vertical direction, the slide-out display  630  of  FIG. 16  provides for automatic extension of the scrolling assemblies  610 ,  612  in the following manner. In this embodiment, as the housing members  614 ,  616  are separated, a driver mechanism coupled with the expanding support  632  extends the scrolling assemblies  610 ,  612  as previously described. In this exemplary embodiment, a rotating head  634  of the scrolling assembly  610  coupled with a second rotating head  636  which is coupled to the expanding support assembly  632 . A second set of rotating heads  638 ,  640  is provided for extending the second scrolling assembly  612 . The rotating head  636  may be coupled to the expanding support assembly  632  by a variety of means. For example, the rotating head can be a gear which engages a rack gear mounted on, or formed into, the support assembly. When the rotating head  636  is a gear, the rotating head  634  coupled to the scrolling assembly  610  may also be a gear which couples to the scrolling assembly by means of a worm gear arrangement. In embodiments where the rotating head  636  coupled to the expanding support  632  is sufficiently proximate to the scrolling assembly  610 , the second rotating head  634  may be eliminated, and the first rotating head  636  may be formed with an additional worm gear for extending the scrolling assembly  610 . Other arrangements as known in the art may also be used. 
         [0058]    With reference now to  FIG. 17 , a third available configuration of a slide-out information display utilizing flexible display membranes is shown. Like the previous embodiment, this embodiment of the slide-out display  650  automatically extends the scrolling assemblies  610 ,  612  as the housing assemblies  614 ,  616  are separated. In this embodiment, however, driver mechanisms  652 ,  654  are coupled to operation of a roller unit of the scrolling assemblies  610 ,  612 . For example, as the flexible display membranes play out, roller units in the scrolling assembly  610 ,  612  cause heads  656 ,  658  to rotate in turn and extend the scrolling assemblies  610 ,  612 . Alternately, a rotating head  660 ,  662  in the scrolling assembly can be coupled by a mechanism such as drive belts  664 ,  666  to the rotating heads  656 ,  658  which extend the scrolling assemblies  614 ,  616 . The coupling mechanisms can be implemented in a variety of ways known in the art. Various combinations of known methods in the art of transmitting mechanical force between objects moving in different directions, such as, e.g., threaded screw heads, drive belts, hydraulic mechanisms, and so on, can be used. 
         [0059]    With reference now to  FIG. 18 , a fourth available configuration  668  of a slide-out information display utilizing flexible display membranes is shown. This configuration is a manual configuration similar to the embodiments shown with reference to  FIGS. 13-15 , however, without housing members. In this embodiment, the scrolling assemblies  610 ,  612  are also slidably mounted so that they can be manually extended or pulled in a direction essentially parallel to the plane of the display membranes. However, in this fourth configuration, each of the extendable scrolling assemblies  610 ,  612  is formed with a tab  670 ,  672  which extends from the face of the respective scrolling assembly. Each tab  670 ,  672  slides in a channel  674 ,  676  formed in the respective remaining scrolling assembly  606 ,  608 . This configuration is further shown with separate telescoping support members  678 ,  680  so that each pair of scrolling assemblies is supported. 
         [0060]    With reference now to  FIGS. 19-20 , and continuing reference to  FIG. 18 , a side view of the fourth available configuration  668  is shown in order to clarify the manual extension of the scrolling assemblies  610 ,  612 . In order to not complicate the drawing, only the left side scrolling assemblies  606 ,  610  are shown in the figure.  FIG. 19  shows the display  668  in a collapsed configuration with the tab  670  in a lower portion of the channel  674 . After manually extending the scrolling assemblies, as shown in  FIG. 20 , the tab  670  is in the upper portion of the scrolling assembly  606 , and the second display membrane  604  is now extended above the first display membrane  603 , with a slight offset to the left as shown. 
         [0061]    It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.