Abstract:
A support structure for at least two flat panel display devices that permits adjustment of the at least two display devices in or about one or more axes, and a display system including such support structure and display devices while maintaining a constant space between the display devices in various configurations, alignments and orientations of the display devices. Such support structure, as provided in accordance with embodiments of the invention, provides for configuration of the at least two display devices, in a plurality of alignments in which fronts of the two display devices are generally aligned in a plane, for viewing together. Embodiments of the support structure provide for the two display devices to be positioned in a landscape and/or portrait configuration. Embodiments of the support structure provide for repositioning the display devices between horizontally and vertically-aligned configurations without disassembling the support structure itself and without disassembling either or both of the two display devices from the support structure.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims priority to U.S. Provisional Application Ser. No. 60/822,589, filed Aug. 16, 2006, which is incorporated by reference herein in its entirety. 
     
    
     COPYRIGHT NOTICE  
       [0002]     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention relates to a support structure for two or more flat panel display devices, and other relatively thin display devices, e.g., flat screen or thin monitors, touch screens, televisions, etc., and to a display system including such support structure and display devices.  
       SUMMARY OF THE INVENTION  
       [0004]     Embodiments of the invention provide a support structure for at least two flat panel display devices (or other relatively thin display devices) that permits adjustment of the at least two display devices in or about one or more axes, e.g., individually, together or cooperatively, and a display system including such support structure and display devices. (Depending upon context, “the at least two display devices” is sometimes referred to as “the two display devices.”) Such support structure, as provided in accordance with embodiments of the invention, provides for configuration of, e.g., two display devices, in a plurality of alignments in which fronts of the two display devices are generally aligned, e.g., in a plane (with or without a display device or devices tilted toward the other display device or devices), for viewing together. Embodiments of the support structure provide for reconfiguring the display devices from one of the plurality of configurations to another of the plurality of positions, e.g., between horizontally and vertically aligned configurations of the fronts of the display devices, and without disassembling the support structure itself and without disassembling either or both of the two display devices from the support structure. (Such configurations of the fronts of the display devices are referred to herein simply as configurations of the display devices.) Embodiments of the support structure provide for the two display devices to be positioned in a landscape and/or portrait configuration or orientation. Thus, for example, in one embodiment, two display devices may be aligned in one configuration, e.g., horizontally, with either or both of the display devices either in landscape or portrait orientation, and may be reconfigured to be aligned, in another configuration, e.g., vertically, with either or both of the display devices either in landscape or portrait orientation.  
         [0005]     In one embodiment, the support structure is supported on a laterally extending surface, e.g., a horizontal surface of a desk top, work station or table. In such an embodiment, the support structure may be supported from a stand contacting the laterally extending surface. An arm extending from a base portion of the stand may be provided to couple the support structure and the base portion. The base portion may or may not be fixed or clamped to the laterally extending surface.  
         [0006]     In another embodiment, the support structure is supported by an upwardly extending surface, e.g., of a desk, work station or table, or by a wall. In such an embodiment, a bracket may be provided for connection, e.g., clamping, to the desk, work station, table or wall, and an arm may be provided extending from the bracket to couple the bracket and the support structure.  
         [0007]     In some embodiments, adjustability may be provided by a stand, bracket or other mounting of the display devices in addition to the adjustability and configurability provided by the support structure.  
         [0008]     In some embodiments, the support structure provides for rotation of each display about a separate axis, e.g., for changing the orientation of a display device between the landscape and portrait orientations.  
         [0009]     According to some embodiments of the invention, the support structure may be arranged so that spacing between adjacent sides of the two display devices may be in separated by a space or gap (or in contact when the space equals zero), whether the two display devices are in vertically or horizontally aligned configurations, in landscape or portrait orientation. In some embodiments, the support structure provides for a space between adjacent sides of the two display devices that is the same when the display devices are in the horizontally aligned configuration and in the vertically aligned configuration. In one embodiment, the space is the same regardless of whether either or both display devices are in landscape or portrait orientation.  
         [0010]     In changing between landscape and portrait orientations of a display device or devices, a display device is rotated about the separate axis, e.g., which extends horizontally. One aspect of the invention provides for the space between the two displays to be maintained the same after one or both displays have been rotated between the landscape and portrait orientations. Rotating the two displays more or less at the same time prevents the displays from contacting each other while being rotated between orientations. Alternatively, the support structure may provide, as described below, for one or both displays to be rotated about an axis perpendicular to the separate axes so that one display may be rotated between orientations without rotating the other display.  
         [0011]     In one embodiment, the support structure supports two display devices for rotation together about a first axis, and for rotation of each of the two display devices individually about a respective second axis, e.g., the second axes are parallel to each other and to the first axis. (Use of the terms “first,” “second,” “third,” “fourth” and “fifth” in connection with axis or axes is for convenience and ease of description.) In this embodiment, the two display devices may be rotated together, e.g., between a horizontally aligned configuration and a vertically aligned configuration, and each of the two display devices may be individually rotated, e.g., between a landscape orientation and a portrait orientation. For example, the two display devices may be reconfigured from a horizontally aligned, landscape orientation to a vertically aligned, landscape configuration by rotating the two display devices about the first axis together from the horizontally aligned to the vertically aligned configurations and also rotating each of the two display devices about a respective second axis to maintain them in landscape orientation, or, after the two display devices are in a vertically aligned configuration, rotating each of the two display devices about a respective second axis from portrait orientation back to landscape orientation.  
         [0012]     In some embodiments, the support structure provides for each of the two display devices to be rotated about a third axis, e.g., perpendicular to the respective second axis. Such rotation about the third axis permits a particular display device to be adjusted relative to the plane described above (in which the fronts of the display devices may be vertically or horizontally aligned) to face towards or away from the other display device, or the fronts of both display devices may be adjusted to face towards or away from each other, etc.  
         [0013]     For smaller spaces between adjacent sides of the two display devices, rotating one of the display devices (or both of the display devices in opposite directions) about the third axis offsets the display devices with respect to the plane referred to above and allows them to overlap and not touch each other during rotation thereof about respective second axes, e.g., rotation of only one display at a time.  
         [0014]     In one embodiment of the support structure, the two display devices are rotatable about a respective second axis which is equidistant from adjacent sides of a respective rectangular display device. For a non-square, rectangular display device, the second axis is not located at the center of the display (which is equidistant from opposite sides of the display). The location of the second axis with respect to a respective display device is selected to provide a desired space between adjacent sides of the two display devices, as described above. Each second axis is offset relative to a non-square flat panel display device such that it is located equidistant from any two adjacent sides of the flat panel display device. This positioning enables the space between the flat panel display devices in horizontally and vertically aligned configurations to be maintained equal.  
         [0015]     In some embodiments, the support structure comprises an arm to which the rear of each display device of the two display devices is rotatably coupled to rotate about a respective second axis, and a respective second axis coupling which rotatably couples a respective display device and the arm. In these embodiments, the support structure may comprise a bracket rotatably coupled to the arm for rotation of the arm (and the two display devices) about the first axis, and a first axis coupling which rotatably couples the respective bracket and the arm. In an embodiment in which the display devices are rotatable about respective third axes, a respective third axis coupling couples a respective second axis coupling to the arm.  
         [0016]     Each second axis coupling may be positioned as discussed above for the second axis, e.g., equidistant from adjacent sides of the respective display device. In various embodiments, the first, second and third axes couplings may include friction, spring, and detent devices, etc., to facilitate rotation, positioning, and configuring of the display devices as described above. For example, the first, second and third axis coupling may be frictionally or spring loaded to maintain the position to which a display has been rotated or to facilitate rotation. In addition, the couplings may include stops or detents to limit the extent of rotation and/or provide for set rotated positions corresponding to horizontally and vertically aligned configurations of the display devices, and portrait and landscape orientation of the display devices.  
         [0017]     A support for two flat panel display devices according to an embodiment of the invention comprises a base, a first arm extending from the base, and a second arm coupled to the first arm, spaced from the base, for rotation about a first axis. Each of the two flat panel display devices are adapted to be coupled to the second arm at spaced locations for rotation about a respective second axis, where each of the second axes is parallel to the first axis, offset from the center of the respective display device and equidistant from adjacent sides of the respective display device. Each of the two flat panel display devices also is adapted to be coupled to the second arm for rotation about a respective third axis normal to the first and second axes. In a display system comprising the two flat panel display devices coupled to the arm for rotation about respective second axes: the two flat panel display devices can be repositioned between a first configuration of the two display devices in which the two display devices are horizontally aligned with a space between the two display devices and a second configuration of the two display devices in which the two display devices are vertically aligned with the space between the first and second display devices by rotating the second arm about the first axis, the space being the same for the first and second configurations of the two display devices; and each of the two flat panel display devices can be repositioned between landscape and portrait orientation by rotation of a respective display device about a respective second axis.  
         [0018]     In some embodiments, a bracket attached to the first arm is rotatably coupled to the second arm for rotation of the second arm about the first axis. In some embodiments, the bracket comprises VESA compliant structure.  
         [0019]     A support for two flat panel display devices according to another embodiment of the invention comprises a base, a first arm extending upwardly from the base, and a second arm coupled to the first arm, spaced from the base, for rotation about a first axis. Each of the two flat panel display devices is adapted to be coupled to the second arm at spaced locations for rotation about a respective second axis parallel to the first axis. Each of the two flat panel display devices also is adapted to be coupled to the second arm for rotation about a respective third axis normal to the first and second axes. In a display system comprising the two flat panel display devices coupled to the second arm for rotation about respective first, second and third axes: the two flat panel display devices can be repositioned between a first configuration of the two display devices in which the two display devices are horizontally aligned and a second configuration of the two display devices in which the two display devices are vertically aligned by rotating the second arm about the first axis; each of the two flat panel display devices can be repositioned between landscape and portrait orientation by rotation of a respective display device about a respective second axis; and each of the two flat panel display devices can be rotated about the third axis in the horizontally and vertically aligned configurations to tilt towards and away from each other. In another embodiment, the support described in this paragraph may provide for rotation of the second arm about an axis perpendicular (sometimes referred to as the fourth axis) to the first axis such that the second arm can be rotated about this axis in the vertically and horizontally aligned configurations to tilt upwardly and downwardly. In another embodiment, the supports described in this paragraph may provide for rotation of the first arm about an axis (sometimes referred to as the fifth axis) such that the first arm, the second arm and the two displays can be rotated relative to the base about this axis. In one embodiment, the fifth axis extends vertically and is parallel to the third axis, and also perpendicular to the base.  
         [0020]     A support for two flat panel display devices according to another embodiment of the invention comprises a bracket, an arm, a first axis coupling that couples the arm to the bracket for rotation about a first axis, a second axis coupling for each of the two flat panel display devices adapted to couple the arm to the respective display device via a respective third axis coupling for rotation about a respective second axis parallel to the first axis, where the second axis couplings are equidistantly spaced from the first axis on opposed sides thereof. A respective third axis coupling is adapted to couple a respective display to a respective second axis coupling for rotation about respective third axis perpendicular to the respective second axes and to the first axis. Each second axis coupling is adapted to be connected to a respective display device at a location offset from the center of the respective display device and equidistant from adjacent sides of the respective display device. In this embodiment:  
         [0021]     the two flat panel display devices can be repositioned between a first configuration of the two display devices in which the two display devices are horizontally aligned with a space between the two display devices and a second configuration of the two display devices in which the two display devices are vertically aligned with the space between the first and second display devices by rotating the second arm about the first axis, the space being the same for the first and second configurations of the two display devices; each of the two flat panel display devices can be repositioned between landscape and portrait orientation by rotation of a respective display device about a respective second axis; and each of the two flat panel display devices can be rotated about the third axis in the horizontally and vertically aligned configurations to tilt towards and away from each other.  
         [0022]     In some embodiments, a detent is provided corresponding to a position of the second arm in which the first and second display devices are in the horizontally aligned configuration and a detent is provided corresponding to a position of the second arm in which the first and second display devices are in the vertically aligned configuration.  
         [0023]     In some embodiments, a detent is provided corresponding to a position of a respective display in landscape orientation and a detent is provided corresponding to a position of a respective display in portrait orientation.  
         [0024]     According to the embodiments disclosed herein, two flat panel displays are supported for adjustment about one, two, three, four or five axes.  
         [0025]     Display systems comprising two flat panel display devices and a support therefor, e.g., as described above, are also provided according to embodiments of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     Embodiments of the invention are illustrated in the figures of the accompanying drawings which are meant to be exemplary and not limiting, and in which like references are intended to refer to like or corresponding parts.  
         [0027]      FIG. 1  is a front perspective view of a display system including a pair of flat panel display devices and a support structure therefor, depicting the display devices supported in a horizontally aligned configuration in a landscape orientation in accordance with an embodiment of the invention.  
         [0028]      FIG. 2  is a rear view of the display system depicted in  FIG. 1 .  
         [0029]      FIG. 3 a  schematic rear view of a flat panel display device of the display system depicted in  FIG. 1  illustrating possible points of attachment of the flat panel device to the support structure for rotation about the second axis referred to above.  
         [0030]      FIG. 4  is a rear view of the display system depicted in  FIGS. 1 and 2  in which the flat panel display devices are being rotated about the first axis referred to above and about the second axis during rotation about the first axis to reconfigure the display devices from the horizontally aligned configuration, landscape orientation depicted in  FIG. 1  to the vertically aligned configuration, landscape orientation depicted in  FIGS. 5 and 6 .  
         [0031]      FIGS. 5 and 6  are front and rear views, respectively, of the display system depicted in  FIGS. 1 and 2  with the display devices supported in a vertically aligned configuration in landscape orientation.  
         [0032]      FIGS. 7-9  are top views of the display system depicted in  FIGS. 1 and 2  illustrating reconfiguration of the display devices from the horizontally aligned configuration, landscape orientation, of  FIGS. 1, 2  and  7  to the vertically aligned configuration, landscape orientation, of  FIGS. 5, 6  and  9 .  
         [0033]      FIGS. 10 and 11  are front perspective views of the display system depicted in  FIGS. 1 and 2  in the horizontally aligned and vertically aligned configurations respectively, with the display devices in landscape orientation and tilted towards each other.  
         [0034]      FIGS. 12 and 13  are front and rear views, respectively, of the display system depicted in  FIGS. 1 and 2 , with the display devices in the horizontally aligned configuration in portrait orientation.  
         [0035]      FIGS. 14 and 15  are front and rear views, respectively, of the display system depicted in  FIGS. 1 and 2 , with the display devices in the vertically aligned configuration in portrait orientation.  
         [0036]      FIG. 16  is a rear view of the display system depicted in  FIGS. 1 and 2 , in which the display devices are being rotated about the first and second axes during reconfiguration of the display devices from the vertically aligned configuration, portrait orientation, depicted in  FIGS. 14 and 15 , to the horizontally aligned configuration, portrait orientation, depicted in  FIGS. 12 and 13 .  
         [0037]      FIG. 17  is a front perspective, partially exploded view of a portion of the display system depicted in  FIGS. 1 and 2  showing the first and third axes couplings in accordance with an embodiment of the invention, and an additional coupling between an upwardly extending arm and a base in accordance with another embodiment of the invention.  
         [0038]      FIGS. 18-20  are views of the second axis coupling for one of the display devices, where  FIG. 18  shows the coupling in a detent position corresponding to landscape orientation of the horizontally aligned configuration of the display device;  FIG. 19  shows the coupling during movement of the display device between the two detent positions of the coupling; and  FIG. 20  shows the coupling in a detent position corresponding to landscape orientation of a vertically aligned configuration of the display device.  
         [0039]      FIG. 21  is an exploded perspective view showing an embodiment of a second axis coupling. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0040]     Embodiments of the present invention will now be described with reference to the drawings. Referring to  FIG. 1 , the display system  100  according to an embodiment of the invention includes two display devices  102  and  103 , sometimes referred to as a dual panel display. Although an embodiment of a multiple display device system is illustrated and described in connection with two display devices, it should be understood that embodiments may include more than two display devices. The display devices  102 ,  103  illustrated in the drawings are flat panel display devices, which may be used for a various applications, e.g., as computer monitors, televisions, presentation devices, etc. The term flat panel display device is meant herein in a broad sense and encompasses various models and types of relatively thin electronic display devices (thin compared, e.g., to cathode ray tube devices). In the embodiment depicted in  FIG. 1 , display devices  102 ,  103  may, for example, be flat panel LCD or plasma type electronic display devices, e.g., of a size suitable for use on a desktop or work station, etc.  
         [0041]     The display devices  102 ,  103  are supported by a support structure  110 , shown for example in  FIG. 2 . In the embodiment depicted in  FIGS. 1 and 2 , the support structure  110  is supported from a stand  112  including a base  114 , adapted to stand on a laterally extending surface such as a desktop, work station top, table top, etc., and an arm  116  that is attached at one end to the base  114  and at the other end to the support structure  110 . The arm  116  may be articulated to the base  114  and/or support structure  110  for, e.g., positioning purposes. In other embodiments, the support structure  110  may be supported from an upwardly extending surface by, e.g., an arm and bracket, or from surfaces and structure using suitable devices.  
         [0042]     Referring to  FIG. 2 , the support structure  110 , comprises a bracket  120  and an arm  122 , and the display devices  102 ,  103  include a rear cover  124 . A first axis coupling  130  ( FIG. 21 ) rotatably couples the bracket  120  and the arm  122  for rotation of the arm  122  (and the display devices  102 ,  103  as a unit) about a first axis  132  (indicated by an “x” mark in  FIGS. 2, 4  and  6 ). The first axis  132  ( FIG. 2 ) extends horizontally and perpendicular to the major sides of the display devices  102 ,  103 . Rotation of the arm  122  about the first axis  132  (see  FIG. 4 ) repositions the display system  100  between a horizontally aligned configuration, landscape orientation ( FIGS. 1 and 2 ) and a vertically aligned configuration, landscape orientation ( FIGS. 5 and 6 ) of display devices  102 ,  103 .  
         [0043]     A respective second axis coupling  134  ( FIG. 17 ) couples the arm  122  and each display device  102 ,  103  (either directly or through a respective third axis coupling  138  where the embodiment provides for rotation about a third axis  140 ) for rotation about a respective second axis  136  ( FIGS. 2, 4  and  6 ). (The second axis coupling is shown in broken lines in  FIGS. 2, 4  and  6 ). Embodiments of the invention may provide a support structure and/or display system in which display devices are rotatable about the second axis alone, or in combination with rotation about one or more other axes, e.g., the first, third, fourth and/or fifth axes. Each second axis  136  extends horizontally, and is perpendicular to the major sides of the respective display devices, and is parallel to the first axis  132 . Rotation of a display device  102 ,  103  about a second axis  136  repositions a display device between landscape and portrait orientations of the display devices when the display devices are not also reconfigured between vertically or horizontally aligned configurations. Rotation of a display device  102 ,  103  about a second axis  136  while the arm  122  and display devices  102 ,  103  are being rotated about the first axis  132  to reconfigure between vertically and horizontally aligned configurations of the display devices maintains the respective display device in the landscape or portrait orientation existing prior to reconfiguration.  
         [0044]     In embodiments providing for rotation about a third axis, a respective third axis coupling  138  ( FIG. 17 ) couples the arm  122  and each second axis coupling  134  for rotation or tilting of a display device  102 ,  103  about the third axis  140  ( FIGS. 2 and 7 ). For example, third axis couplings  138  provide for tilting of the respective display devices, e.g., towards each other, as shown for example in  FIGS. 10 and 11  (or away from each other, etc.), and for offsetting the display devices when the display system configuration is being changed between horizontally and vertically aligned configurations, as shown for example in  FIGS. 7 and 8 . Referring to  FIGS. 2 and 7 , the third axis  140  extends vertically with respect to the display devices and is perpendicular with respect to the first axis  132  and the second axes  136 .  
         [0045]     The first axis coupling  130  ( FIG. 21 ) may be any suitable rotation or pivot joint that allows for rotation of the arm  122  about the first axis  132  ( FIGS. 2 and 4 ) with respect to the bracket  120  while maintaining the rotated position of the arm  122  at least at home, e.g., detent, positions corresponding to a horizontally aligned configuration ( FIGS. 1 and 2  for landscape orientation and  FIGS. 12 and 13  for portrait orientation), and a vertically aligned configuration ( FIGS. 5 and 6  for landscape orientation and  FIGS. 14 and 15  for portrait orientation). A specific implementation of the first axis coupling  130  is described below in connection with  FIG. 21 .  
         [0046]     The bracket  120  ( FIG. 4 ) is positioned sufficiently spaced from the base  114  such that the arm  122  with the display devices  102 ,  103  may rotate about the fist axis  132 , with appropriate rotation of display device  102  and  103  about respective second axes  136 , without contacting the base  114  during reconfiguration between horizontally and vertically aligned configurations. Bracket  120  may be a Video Electronics Standards Association (VESA) compliant plate, or any suitable bracket. Correspondingly, the arm  122  is preferably VESA compliant to facilitate mounting thereof to bracket  120 . If desired, a VESA compliant bracket  120  may be attached to any VESA-compliant device, and the base  114 , arm  116  and bracket  120  may be provided as a VESA compliant support. Similarly, the arm  122  may be attached to other suitable VESA compliant support devices.  
         [0047]     The second axes coupling  134  ( FIG. 2 ) may be any suitable rotation or pivot joint that allows for rotation of a display device  102 ,  103  about the second axis  136  with respect to the arm  122  while maintaining the rotated position of the display device at least at home, e.g., detent, positions corresponding to a landscape orientation ( FIG. 1 ) and a portrait orientation ( FIG. 12 ). A specific implementation of a second axis coupling  134  is described below in connection with  FIG. 17 .  
         [0048]     Referring to  FIG. 3 , the second axis  136  is positioned equidistant from any respective two adjacent edges of a respective display device  102 ,  103 . In the illustrated embodiments, the overall geometric shape of displays  102 ,  103  is rectangular but not square. Therefore, a point that is equidistant from adjacent sides would not be in the geometric center of the display device (midway between each pair of opposite sides), but offset therefrom. Locating the second axis  136  at a point equidistant from adjacent sides of a respective display  102 ,  103  enables a selected space “s” (which could be zero, as mentioned above) (determined as described herein) (see  FIGS. 1, 5 ,  12  and  14 ) to be maintained between displays  102 ,  103  when in the horizontally aligned and vertically aligned configurations. The space “s” is determined by the dimensions of the displays and an equal distance from the first axis  132  to each second axis  136 . Positioning of second axis  136  is also selected to provide for a desired alignment of the displays  102 ,  103  in various configurations and orientations. For 15 inch display devices and a space “s” in the range of ¼ inch to ¾ inch, the second axis  136  is located in the upper right quadrant of display device  103  near the geometric center as viewed from the back thereof (where the display system is in horizontally aligned configuration, landscape orientation). The exact position will depend on the exact dimensions of the display device and can easily be determined based on the description herein. This offset location of the second axis  136  maintains the same set space “s” between display devices when the display devices are in a horizontally aligned configuration (in both landscape and portrait orientations) ( FIGS. 1 and 5 ) and in a vertically aligned configuration (in both landscape and portrait orientations) ( FIGS. 12 and 14 ), which unifies the presentation of display devices  102 ,  103  regardless of the particular configuration and orientation of the display devices.  
         [0049]      FIG. 3  illustrates possible positions of second axis  136  on a display device, e.g., display device  103 . Points equidistant from adjacent sides  142 ,  143  of the display define a line  145 , which is not a diagonal and does not pass through the geometrical center of the display. Therefore, points on line  145  are offset as described above. Placement of second axis  136  on line  145  maintains the set spacing “s.” As mentioned, a particular selected point on line  145  of axis  136  provides for a desired relative positioning of the displays in various configurations and orientations. The point that corresponds to a desired relative positioning can be easily determined, e.g., empirically.  
         [0050]      FIGS. 2, 4  and  7 - 9  illustrate changing the presentation display system configuration of display devices  102 ,  103  from horizontally aligned, landscape orientation, to vertically aligned, landscape orientation. (Changing from a vertically aligned configuration to a horizontally aligned configuration is similar and therefore will not be described in detail.) The change between horizontally aligned and vertically aligned configurations of display devices  102 ,  103  includes a rotation of arm  122  about the first axis  132  ( FIG. 4 ) (which provides for the change between horizontally and vertically aligned configurations) and rotation of each display about a respect second axis  136  (which maintains the particular landscape or portrait orientation). As discussed above, to provide clearance between display devices  102 ,  103  during the rotation thereof about respective second axes  136 , one of the display devices  102 ,  103  is rotated (tilted) about the third axis  140 , as illustrated in  FIGS. 7-8 . With display device  102  being rotated about second axis  136  ( FIGS. 7 and 8 ), clearance is provided between display devices  102  and  103  as arm  122  is rotated about the first axis  132  and each display device  102 ,  103  is rotated about a respective second axis  136 , as illustrated in  FIGS. 4 and 8 .  FIGS. 1, 2  and  7  illustrate the relative positions of the display devices and the first, second and third axes in the horizontally aligned configuration, landscape orientation, and  FIGS. 5, 6  and  8  illustrate the relative positions of the display devices and the first, second and third axes in the vertically aligned configuration, landscape orientation.  
         [0051]     With the displays in portrait orientation ( FIGS. 12-15 ), the reconfiguration between horizontally aligned and vertically aligned configurations is similar to the reconfiguration described above for landscape orientation. After one of the display devices  102  or  103  is tilted about a third axis  140 , arm  122  is rotated about first axis  132  and each of the displays  102 ,  103  is rotated about a respective second axis  136  to maintain the portrait orientation of each display, as illustrated in  FIG. 16 .  
         [0052]     Each of the third axis couplings  138  ( FIG. 17 ) may be any suitable rotation or pivot joint that allows for limited rotation or tilting of the respective display device  102 ,  103  about a respective third axis  140  while maintaining the rotated or tilted position of the respective display. A specific implementation of a third axis coupling  138  is described below in connection with  FIG. 17 .  
         [0053]     Each display device  102 ,  103  can be independently tilted towards or away from each other in both the vertically aligned and horizontally aligned configurations, in both landscape and portrait orientations. This is illustrated in  FIG. 10  where the display devices  102 ,  103  are tilted about a respective third axis  140  ( FIG. 2 ) towards each other in the horizontally aligned configuration, landscape orientation, and in  FIG. 11 , where the display devices  102 ,  103  are tilted about a respective third axis  140  towards each other in the vertically aligned configuration, landscape orientation. As mentioned, tilting is accomplished by rotating a particular display about its third axis  140 . The displays  102 ,  103  can similarly be tilted in portrait orientations not shown.  
         [0054]     The first axis coupling  130  and both second axes couplings  134  are similar. Therefore, much of the following description of the second axes couplings  134  will apply to the first axis coupling  130 . The second axis coupling  130  for display  103 , as illustrated in  FIG. 17  (which omits the display device  103  and various screws, washers, gaskets, etc., for clarity), includes a hub assembly  160  that rotatably couples the arm  122  to the display  103  (via third axis coupling  138 ). In the illustrated embodiment, the hub assembly is held between the rear cover  124  and the rear head frame  164  ( FIG. 2 ) of the display device  103 . The rear cover  124  is attached to the rear head frame  164  via screws (not shown) and threaded posts  166 . In another embodiment, not illustrated, the hub assembly is held on the inside of the rear head frame  164  between the rear head frame and a head case assembly (not shown) of the display. In both embodiments, a part of the hub assembly is captivated between two parts, i.e., either between the rear cover  124  and the rear head frame  164 , or between the rear head frame  164  and a head case assembly.  
         [0055]     The hub assembly  160  ( FIG. 17 ) comprises a hub  168  captivated in a hub housing  170  which includes a frame  172 , attached to or forming part of the rear cover  124 , and a housing cover  174  attached to the housing frame by screws (not shown) and threaded posts  176 . The hub  168 , captivated in the hub housing  170 , and the rear cover  124  are relatively rotatable. The rear cover  124  includes a hole  178  therethrough within the housing frame  172 . A mounting disc  180  fixed to the third axis coupling  138  in alignment with the hole is attached to the hub  168  by screws (not shown) that pass through holes  182  in the hub  168  and are threaded to threaded posts  184  on the mounting disc  180 . This arrangement allows the rear cover  124  with the display  103  attached thereto to be rotated relative to the arm  116 , as illustrated, for example, in  FIG. 4  (the hub  168  is fixed to the arm  116  via the mounting disc  180  and the third axis coupling  138 , and is rotatable within the hub housing  170  relative to the rear cover  124 ). A detent mechanism  188 , described below, provides detent positions for the hub  168  corresponding to the landscape and portrait orientations of the particular display  102 ,  103 .  
         [0056]     Referring to  FIGS. 18-20 , the hub  168  is generally disc-like or cylindrical and the hub housing  170  defines a generally cylindrical space  190  within which the hub  168  is received. The housing space  190  and the hub  124  are complementarily configured and sized to permit relative rotation between the two with minimum lateral and axial movement. The detent mechanism  188  is provided as follows. The hub housing  170  includes a blind slot  192  which extends radially with respect to, and opens into, the housing space  190 . A coil spring  194  is loaded in the slot  192  and urges a ball bearing  196  positioned at the open end of the slot against the outer periphery of the hub  168 . This loads the hub  168  and reduces lateral movement of the hub  168  in the hub housing  170  while introducing a frictional drag to relative rotation between the hub and the housing (which acts to lightly load a display device in a rotated position other than a detent position). The periphery of the hub  168  includes two circular recesses  198  and  199  spaced 90° apart sized to receive a substantial portion of the ball bearing  196  therein. The recesses  198  and  199  cooperate with the ball bearing  196  and the spring  194  to provide detents at the recesses  198  and  199  which define two relative positions of the hub  168 , 90° apart, in the hub housing  170 , as illustrated in  FIGS. 18 and 20 .  FIG. 18  illustrates the hub  168  in one detent position with the ball bearing  196  engaged in recess  198 , and  FIG. 20  illustrates the hub  168  in the other detent position with the ball bearing  196  engaged in recess  199 . Clockwise movement of the rear cover  124  (to which the hub housing  170  is attached) releases the hub  168  from engagement at recess  198  and into engagement at recess  199  with ball bearing  196 , and counter-clockwise movement of the rear cover  124  releases the hub from engagement at recess  199  and into engagement at recess  198  with ball bearing  196 . The two engaged positions of hub  168  illustrated in  FIGS. 18 and 20  correspond to landscape and portrait orientations of the particular display. The circular configuration of the recesses  198  and  199  facilitates seating and de-seating of the ball bearing  196  therein, and performs a camming function associated with the detent mechanism  190 . The relative positions of the hub housing  168  (and rear cover  124 ) and the hub  168  in  FIGS. 18-20  respectively correspond to the positions of display device  103  in  FIGS. 2, 4  and  5  (where the second axes couplings  134  are shown in broken lines).  
         [0057]     The first axis coupling  130 , illustrated in  FIG. 21 , is similar to the second axis coupling  134  and comprises a hub assembly  160   a  that provides for relative rotation between the arm  116  and the stand  112 . The hub assembly  160   a  comprises a hub  168   a  captivated in a hub housing  170   a  formed in the inside, rear of the bracket  120  and closed by a plate  174   a  attached to the bracket by screws  185 , holes  186  and threaded posts  187 . The hub  168   a  is fixed to the arm  122  (and thereby supports the arm  122  from the stand  112 ) by screws (not shown) which pass through the arm  122  and a central hole  178   a  in the bracket  120  and are received in the four screw holes  201  in the central region of the hub  168   a . The bracket  120  is fixed to the stand  112  via a hinge  203  (not shown in other figures), which allows the displays  102 ,  103  to be tilted as a unit relative to the stand  112 . Thus, the arm  122  and attached hub  168   a  are rotatable relative to the bracket  120  and stand  112 , as illustrated in  FIG. 4 , and generally as described above for hub assembly  160 .  
         [0058]     Like the hub assembly  160 , the hub assembly  160   a  includes a detent mechanism  188   a  with two detent positions defined by recesses  198   a  and  199   a  in the outer periphery of the hub  168   a , and a ball bearing  196   a  loaded against the outer periphery of the hub  168   a  by a coil spring  194   a  in a slot  192   a . The two detent positions of the hub assembly  160   a  correspond to the horizontally aligned and vertically aligned configurations of the display devices  102 ,  103 .  
         [0059]     Each third axis coupling  138 , illustrated in  FIG. 17 , comprises a tubular hinge  205  including upper and lower hinge bodies  207 ,  208  fixed to the arm  122  by screws (not shown) received in posts  210  and a rotatable hinge body  212  attached to a respective mounting disc  180  of the respective hub assembly  160  described above. The upper and lower hinge bodies  207 ,  208  each includes a reduced diameter portion  214  which rotatably nests in an opposite end of the rotatable hinge body  212 . Alternatively, a hinge pin (not shown) may be fixed to hinge bodies  207 ,  208  and rotatably receive the rotatable hinge body  212 . As discussed above, the mounting disc  180  is attached to the hub  168 , so that the rotatable hinge body  212  rotatably supports a respective display from the arm  122 . The rotation provided by the tubular hinges  205  allows the respective display devices to be tilted towards or away from each other, as described above.  
         [0060]     Referring to  FIG. 17 , the displays  102  and  103 , the support structure  110  and the arm  116  may be rotated relative to the base  114  in accordance with another embodiment of the invention. In this embodiment, the arm  116  may be rotated about an axis  220  (sometimes referred to as the fifth axis), which in the illustrated embodiment extends perpendicularly to the base  114 , e.g., extends vertically. In the illustrated embodiment, axis  220  is parallel to the third axis  140 . Any suitable coupling  222  may be used to couple the arm  116  to the base  114  for such rotation.  
         [0061]     Embodiments of the disclosed invention have been described and illustrated in an exemplary and non-limiting sense, and the invention as defined by the claims is not to be limited to the precise details of methodology or construction set forth above.  
         [0062]     For example, while support structures for two display devices have been illustrated and described, support structures for other embodiments may include more than two display devices. Also, couplings other than those illustrated may be used.