Abstract:
An apparatus for mounting and arranging a plurality of flat panel video display assemblies. An a arcuate receiver segment has a lower surface for attachment to a support and an upper surface for receiving a connection plate. A connection plate is attached to the bottom of each display assembly. The receiver segment includes a central registration pin about which an edge cutout on the connection plate is aligned. The base plate has two locking tabs in spaced relation on either side of the registration pin. Each display assembly is lowered over and rotated about the registration pin so that opposed edges of the connection plate slide into respective locking relation with the locking tabs. Ten receiver segments are arranged to form a circle for mounting ten video displays. Adjacent display assemblies are fastened together to form a mechanically secure and visually seamless display.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to 360 degree video display systems, used in training or entertainment devices. More specifically, the invention pertains to an apparatus for mounting and arranging a plurality of flat panel video display assemblies, in which a plurality of arcuate receiver segments is arranged on a base plate to form a base ring, bottom edges of individual panels are lowered upon and rotated into locking engagement with a respective receiver segment, and adjacent panels are respectively attached to each other to form an inwardly directed circular array. 
   2. Description of the Prior Art 
   The prior art teaches the use of CRT display systems as visual aids in training devices or simulators. For example, air flight simulators used for pilot training, may use four to six CRTs installed in the cockpit “windows” of the simulator. Video information, corresponding to a prerecorded program as modified by the interaction of the student with that program, is displayed on the CRTs to simulate the visual experience of takeoff, flying, and landing procedures. 
   Similar arrangements have been used for other simulators, such as military tank trainers. However in this instance, the visual experience presented by the display must encompass 360 degrees, as opposed to the relatively narrow field of view presented by a flight simulator display. For the purpose of presenting a 360 degree visual display, the prior art teaches the use of five CRT assemblies, each including two CRTs, arranged to form a ring, with the light output of the CRT assemblies pointed inwardly toward the trainee. Each CRT assembly includes a downwardly directed, vertical CRT and a forwardly and inwardly directed, horizontal CRT. A computerized system feeds each CRT in the assembly with different video information, pertaining to physically contiguous fields of view. A beam splitter, interposed between the intersecting light outputs of the CRTs, redirects and reintegrates the visual information, so that a substantially seamless 72 degree field of view is presented to the viewer by each CRT assembly. The beam splitter does this by reflecting the light from the vertical CRT and by allowing throughput transmission of the light from the horizontal CRT. 
   CRTs have a number of drawbacks when used to simulate a circular 360 degree field of view, such as those used in a military tank trainer. CRTs are heavy and cumbersome to mount in the CRT assemblies which form a circular array. CRTs require a significant amount of room behind the CRT screen itself, to accommodate the rearwardly extending necks which house the electronic guns. Most of this room goes unused, resulting in a bulky and space inefficient arrangement. The computer system required to route and direct different video information to the CRTs is complex and expensive. The beam splitter used to redirect and reintegrate the visual outputs of the CRTs is also complex and expensive to manufacture. Lastly, CRTs in such applications are usually powered up continuously, and begin to lose light output and sharpness after a period of time as the electron guns and the phosphors degrade. Replacement of the CRTs is a labor intensive process, requiring down time when the training apparatus cannot be used. 
   Thus, the need exists for a video display replacement for the CRTs, which provides a high quality 360 degree image, and is also compact in size, lightweight, and easy to assemble and service. 
   The need further exists for an apparatus for mounting and arranging a plurality of flat panel video display assemblies, which can either be retrofitted to an existing training apparatus, or employed in a newly manufactured training apparatus, without modification. 
   The need also exists for a mounting and arranging system for a plurality of flat panel video display assemblies which allows an individual panel to be removed or replaced without disturbing the mounting or alignment of adjacent panels. 
   The need further exists for a mounting and arranging system for a plurality of flat panel video display assemblies in a circular array, in which the panels are self aligning, allowing the quick assembly, disassembly, and reassembly of the array without special tools or instruments. 
   SUMMARY OF THE INVENTION 
   The apparatus of the present invention employs a plurality of flat panel video display assemblies. Each video display assembly includes a display screen and a surrounding frame. The display screen is preferably an Active Matrix Liquid Crystal Display (“AMLCD”). The surrounding frame has a top plate, opposing, vertical side plates, and a bottom connection plate. The top plate includes a flange extending outwardly and horizontally from its left hand end, with a screw hole. The top plate has a similar flange extending from its right hand end, provided with a screw. The connection plate includes a centrally positioned cutout along an edge of a front flange. The cutout is used for alignment purposes during the installation of each panel. 
   The video display assemblies are mounted upon a circular base ring. The base ring is comprised often arcuate receiver segments. Each receiver segment spans a 36 degree arc, so that when ten receiver segments are arranged in abutting relation, the circular base ring is formed. Each receiver segment is dedicated to the support and alignment of a respective video display assembly. For that purpose, the upper surface of each receiver segment includes a pair of locking tabs equally spaced on either side of a centrally positioned registration pin. 
   The array is assembled by individually mounting each display assembly upon a respective receiver segment of the base ring, and then interconnecting top plates of adjacent display assemblies to each other. This is accomplished by initially lowering a first display assembly onto the upper surface of a receiver segment with the registration pin of the receiver segment nested within the cutout of the connection plate. At this point, the axes of the receiver segment and connection plate are askew, approximately 30 degrees or so. Maintaining the pin/cutout alignment, the display assembly is rotated about its vertical axis. Toward the end of this rotation of the display assembly, front and rear flanges of the connection plate slide underneath the locking tabs on the receiver segment until fully seated. 
   This process is repeated with the next display assembly. However this time, one top plate of the first display assembly comes into slightly overlapping relation with another top plate of the second display assembly, when the latter is rotated into its locking position. A screw in the top plate of the second display assembly is screwed into a respective hole in the top plate of the first display assembly. The slight overlap between the assemblies provides a nearly seamless match between adjacent display assemblies. 
   Successive display assemblies are mounted to the base ring and to each other in identical fashion, until the entire circular array is formed. The viewing area of each of the displays is directed inwardly, toward a center point of the array. Perfect angular alignment of the displays is ensured by the geometric configuration formed by the base ring which is mimicked by the array of display assemblies mounted thereon. The locking interconnections between the display assemblies and the receiver segments, coupled with the screw interconnections between adjacent assemblies, provide a rigid and accurately aligned array. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a plurality of flat panel video display assemblies arranged and assembled on a decagon base to form a circular array; 
       FIG. 2  is an exploded perspective view of a receiver segment and a fragmentary portion of the base plate, showing the three alignment pins; 
       FIG. 3  is an exploded perspective view of a flat panel display assembly being installed on an arcuate receiver segment, illustrating engagement between the flanges on the bottom connecting plate and the locking tabs on the receiver segment; 
       FIG. 4  is a top plan view of a first display assembly and a fragment of a second display assembly, fully installed on their respective receiver segments; 
       FIG. 5  is a detail inset view of the right hand rear corner of the display assembly in  FIG. 4 , but showing the upper registration hole in the rear flange out of alignment with the lower registration hole in the receiver segment; 
       FIG. 6  is a view as in  FIG. 5 , but showing the upper registration hole and the lower registration hole in alignment, after the display assembly has slightly been rotated in clockwise fashion; 
       FIG. 7  is a detail view showing the slight side edge overlap between adjacent display assemblies; 
       FIG. 8  is a top plan view of the circular array of flat panel display assemblies, showing the entirety of base plate and the fully assembled base ring; 
       FIG. 9  is a fragmentary perspective view of two display assemblies, the left hand assembly in the process of being rotated about its vertical axis into a locked position; and, 
       FIG. 10  is a view as in  FIG. 9 , after the left hand display assembly has been rotated into a fully locked position, and after the locking screw in the right hand display assembly has been secured into a threaded hole in the top plate flange of the left hand display assembly. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Turning now to the drawings, and in particular  FIG. 1 , ten flat video display panel assemblies  11  are arranged and assembled to form a generally circular array  12 . The size of the array  12  is not critical, but in applications where the array is used as a video display for a tank training simulator, the diameter of the array is approximately four to five feet. This is large enough so that at least one person can comfortably operate within a large center aperture  13 , surrounded by the array  12 . (See,  FIG. 7 ). The size of each display assembly for the typical training simulator will range from approximately twenty to twenty-five inches on the diagonal. For other applications, such as home or public theater displays, the number, size, and configuration of the display assemblies as well as the diameter of the array, may be quite different. 
   The display panel assembly  11  includes a flat display screen  14  provided with a surrounding frame  16 . Preferably, screen  14  is of the type known as an Active Matrix Liquid Crystal Display (hereinafter, “AMLCD”). Modern AMLCDs have overcome two major faults which were characteristic of prior LCD display panels: (1) poor resolution; and, (2) slow turn-on/turn-off time, when compared to conventional Cathode Ray Tubes. With image resolution and pixel response time approaching or equaling that of CRTs, modern AMLCDs are now the display device of choice for many video display applications. However, the apparatus of the present invention may also be used in conjunction with other flat panel video display technologies, such as plasma and digital micro-mirror device (“DMD”) displays. The AMLCD screen which has been used successfully by the inventor is the Model LTM213U3-L07,manufactured by Samsung Electronics, of Chonan, Korea. 
   Surrounding frame  16  is comprised of a top plate  17 , opposing, vertical side plates  18  and  19 , and a bottom connection plate  21 . The top plate  17  has first connection means including a first flange  22  extending outwardly from its left hand end. Flange  22  is provided with a screw hole  23 . The top plate also has second connection means including a second flange  24  extending from its right hand end. Flange  24  is provided with a captive screw  26 . The bottom connection plate  21  is perpendicular to screen  14  and includes a front flange  27  and a rear flange  28 , extending, respectively, forwardly and rearwardly from the screen  14 . Front flange  27  has a centrally positioned triangular-shaped cutout  29 . The corner portions of rear flange  28  include upper registration holes  31  and  32 . (See,  FIG. 4 ). As will be explained more fully below, cutout  29  and upper registration holes  31  and  32  are used for alignment purposes during the installation of each display assembly  11 . 
   The lower, rear side of display assembly  11  includes a control and interconnection panel  25 , having a power switch  30  and connection jacks  35 . Power, video, and control signals are fed to the connection jacks of the display assembly through a plurality of cables, not shown in the drawings. 
   A decagonal base plate  33  forms the primary structural support for the array  12 . Base plate  33  is provided with a circular center aperture, mentioned above, sized to accommodate at least one person. The circular array  12  of the present invention may be used advantageously in connection with an existing tank training simulator (not shown), in which the old CRT displays are replaced with the display assemblies  11 . In such a retrofit application, the existing base plate  33  may have to be tapped or bored with new holes to accommodate a plurality of upwardly extending registration pins  34 . Array  12  may also be used in new tank training simulators, in which case holes for the registration pins  34  would be fabricated as part of a newly manufactured base plate  33 . It should also be noted that where the array  12  of the present invention is used for other applications, a substitute equivalent support may be used in lieu of base plate  33 . For example, a floor or other substrate could be easily substituted. 
   A circular base ring  36  is assembled to overlay the base plate  33 . Ring  36  is comprised of ten arcuate receiver segments  37 , with each segment spanning a 36 degree arc. To ensure proper alignment between the receiver segments and the base plate, each receiver segment  37  includes three registration apertures  38 . As shown in  FIG. 2 , the locations of registration apertures  38  correspond the locations of respective underlying registration pins  34 . Each receiver segment is successively aligned with and lowered over its set of registration pins. When all ten receiver segments are arranged in lateral edge-abutting relation over base plate  33 , the 360 degree base ring  36  is formed (See,  FIG. 8 ). 
   Each receiver segment  37  is dedicated to the support and proper radial alignment of a respective video display assembly  11 . To accomplish that purpose, the upper surface  39  of each receiver segment includes a first locking tab  41  and a second locking tab  42 . Locking tabs  41  and  42  are located in spaced relation on either side of a registration pin  43 . First locking tab  41  has an entry portion  44  facing in one direction toward the center aperture  13 . Second locking tab  42  has an entry portion  46  facing in another direction, away from the center aperture. As is evident from  FIG. 2 , entry portion  44  and entry portion  46  are oriented in opposite directions. 
   Lower registration holes  47  and  48  are provided in the left hand and right hand rear portions of receiver segment  37 . These lower registration holes are used in the installation of each display assembly and the associated alignment process between the connection plate  21  and the underlying receiver segment  37 . 
   After the base ring  36  is fully formed, assembly of the circular array  12  can begin. Making particular reference to  FIG. 3 , a display assembly  11  is lowered into position over a respective receiver segment  37 . Assembly  11  is initially oriented with its left hand side toward the rear of ring  36  and its right hand side toward the front of ring  36 . Triangular-shaped cutout  29  is aligned with respect to segment  37  so that registration pin  43  is nested within the apex of cutout  29 . With connection plate  21  now resting upon the upper surface  39  of segment  37 , display  11  is manually rotated in a counter-clockwise fashion about its vertical axis. As rotation of the display assembly  11  about registration pin  43  continues, the front and rear flanges  27  and  28  pass through respective entry portions  44  and  46 , and engage tabs  41  and  42 . 
   Display assembly  11  must still be counter-rotated, to a slight degree and in a clockwise fashion, to complete the alignment process. Making reference to  FIG. 5 , it can be seen that the upper registration hole  32  is out of axial alignment with lower registration hole  48 . Similarly, on the left hand side of assembly  11 , upper registration hole  31  is out of axial alignment with lower registration hole  47 . With a slight clockwise rotation of the assembly  11 , the upper and lower registration holes become aligned and axially coincident, as shown in  FIG. 6 . 
   With the installation of a first assembly  11  completed, a second assembly  11  is mounted on an adjacent receiver segment  37 , in identical fashion. The installer can proceed with the installation of the next display assembly either to the left or to the right of the first display assembly. However, it is preferred to install successive display assemblies in a clockwise direction.  FIG. 9  shows the first assembly already in place, while the second assembly is in the process of being rotated into a locked position.  FIG. 10  shows the relative positions of the two assemblies after rotation is completed. Screw  26  in top plate  17  of the first assembly is manually rotated so that it threadably engages screw hole  23  in top plate  17  of the second assembly. 
   As is evident from  FIG. 7 , when the right hand display assembly is rotated into position adjacent the left hand display assembly, there is a physical overlap  49 , between the adjacent side edges of the two assemblies. The purpose of the overlap is to minimize the gap, or visual display dead space, between the two screens. In practice, the gap has been reduced to approximately 0.250″, so that the visual continuity between the screens of adjacent display assemblies is quite good. Another way of expressing this overlap is the fact that a perpendicular line from the center of screen  14  does not pass directly through center of the center aperture  13 , but is slightly offset therefrom. This slight offset is predetermined by the location of the lower registration apertures  47  and  48  in receiver segment  37 . 
   Successive display assemblies  11  are installed until the entire circular array  12  is formed, as shown in  FIGS. 1 and 8 . Despite the fact that each assembly is “floating”, as it is not rigidly affixed to the base ring, the array is quite rigid and stable. This stems from the geometric configuration of the array, the mechanical restraint provided by the connectors between the assemblies, and the mechanical restraint provided by the flange and tab arrangement. 
   One of the unique advantages provided by the “floating” mounting system, is the avoidance of mechanical multiplication of tolerance deviations. For example, if the assemblies were rigidly attached to the receiver segments, small tolerance deviations from assembly to assembly could build up so that attachment to both the segment and the adjacent assembly would be difficult or impossible. In the apparatus of the present invention, the mechanical interconnection between adjacent display assemblies is effected very quickly and easily, because the flange and tab arrangement allows small movements of the assemblies during interconnection. However, when the display assemblies are all mounted and interconnected, the array is unexpectedly rigid and stable. Another unique advantage provided by the mounting system is the ability, easily and quickly, to remove a single display assembly, for repair or replacement, without disturbing the integrity of the remaining array. Installation of a new or repaired display assembly takes just a few minutes, and requires no special tools or any additional alignment procedure to complete.