Abstract:
A mobile interactive presentation and collaboration system having a projector carriage is positioned rearward of a screen assembly such that a projector positioned on the projector carriage operates as a counterweight balancing the screen assembly to prevent die screen assembly from tipping forward. The projector carriage is positioned at the base of the screen assembly to lower the center of gravity of the system to further improve the stability of tire system.

Description:
RELATED APPLICATIONS 
     The present application is a National Stage entry of PCT Application No. PCT/US2013/027401 filed Feb. 22, 2013, which claims the benefit of U.S. Provisional Application No. 61/603,158 entitled MOBILE INTERACTIVE PRESENTATION AND COLLABORATION SYSTEM and filed Feb. 24, 2012, said applications being hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to mobile interactive presentation and collaboration systems. Specifically, the present invention is directed to a mobile interactive presentation and collaboration system having a short-throw rear projector. 
     BACKGROUND OF THE INVENTION 
     Interactive computer based presentation and collaboration system have recently seen increased use. These collaboration systems often comprise a large interactive display that permits multiple users to simultaneously view and interact with the display. However, due to the high cost and substantial inconvenience of installing these systems, it is often highly desirable that the systems be mobile to allow a single system to be moved between multiple locations such as multiple conference rooms. Similarly, certain meeting spaces may not be suited for permanent installation of the systems or intended for only as a one-time meeting space. 
     An approach to making these systems mobile is pairing a short throw projector with a conventional whiteboard mounted a wheeled cart. Typically, the projector is a separate system that is positioned a distance from the cart and aimed at the white board. A drawback of this approach is that users often walk in front of the projector or standing at the white board blocking or partially obscuring the projected image. Alternatively, the projector is suspended from an arm extending from the top of the projector. The extreme angle of the projector reduces the likelihood that a user will be positioned to block the image. However, an inherent drawback of this system is that the top mounted arm with the extended projector can make the system is top-heavy and prone to tipping. Similarly, the front wheels of the cart must project substantially in front the white board to prevent the whiteboard from tipping forward. In particular, the top arm used to suspend a front projector in front of the screen shifts the center of mass of the system forward creating an even greater risk of the screen tipping forward. This arrangement can make accessing the whiteboard difficult or create a tripping hazard as users often move in front of the whiteboard during a presentation or collaboration. 
     A similar drawback is that a direct projection of the image onto the front of a whiteboard often produces an inferior quality image. For example, any residue left from writing on whiteboard with dry erase markers can degrade or obscure the projected image. Similarly, whiteboard materials are prone to warping, which can further distort the projected image. 
     Accordingly, there is a need for a mobile interactive presentation and collaboration system that addresses the drawbacks of presently available system. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a mobile interactive presentation and collaboration system having a screen assembly and a projector carriage, both positioned on a wheeled cart. The projector carriage is positioned rearward of the screen assembly and oriented in a generally horizontal orientation for receiving a short throw rear projector for projecting an image against a generally vertical rear projection surface of the screen assembly. In certain embodiments, the projector carriage projects rearward from screen assembly proximate to or at the bottom of the rear projection surface such that a projector positioned on the horizontal shelf acts as a counterweight preventing the rear projection surface from tripping forward. In other embodiments, the projector carriage is positioned on the wheeled cart rearward of the rear projection screen such that the projector back weights the wheeled cart to prevent the screen assembly from tipping forward. 
     The counter weighting of the screen assembly by the horizontally oriented rear projector allows the screen assembly to be positioned closer to the front portion of cart chassis than a conventional system having a top arm suspending a front projector in which requires that a portion of the chart chassis to project in front of the screen assembly to prevent the screen assembly from tipping forward. Similarly, the low position of the projector at or proximate the bottom of the screen assembly improves the overall stability of the system. Accordingly, the counterbalancing of the screen assembly with the projector allows the cart chassis to have a smaller footprint making the system more easily moved. 
     The rear projection screen comprises a semi-transparent material such as a vinyl projection screen, tempered glass pane, polycarbonate or other acrylic material capable of displaying the image projected by the rear projector such the image can be viewed from the front of the projection screen. In certain embodiments, the rear projection screen can comprise a rigid material allowing the rear projection screen to be marked on the front side with an erasable marker or similar writing utensil to allow users to mark or annotate the images projected onto the rear projection screen. 
     A mobile interactive presentation and collaboration system, according to an embodiment of the present invention, comprises a cart chassis, a screen assembly and a projector carriage. The cart chassis comprises an elongated front member and at least two side members projecting rearward from the front member to support the front member in a front to back direction. Similarly, the screen assembly comprises two side supports projecting vertically from the cart chassis and supporting a rear projection screen in a generally vertical orientation, wherein the rear projection screen comprises a front face and a rear face and positioned substantially forward of a midpoint of the side members of the cart chassis along the front to back direction. The projector carriage defines a generally horizontal shelf for receiving a projector for directing an image at the rear face of the rear projection screen, wherein the projector carriage is positioned rearward from the rear projection screen at about the bottom of the rear projection screen such that the projector counterweights the screen against tipping forward. 
     The above summary of the various representative embodiments of the invention is not intended to describe each illustrated embodiment or every implementation of the invention. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the invention. The figures and the detailed description that follow more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The embodiments of the present invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which: 
         FIG. 1  is a top plan view of a mobile interactive presentation and collaboration system according to an embodiment of the invention; 
         FIG. 2  is a front elevation view of the system of  FIG. 1 ; 
         FIG. 3  is a side elevation view of the system of  FIG. 1 ; 
         FIG. 4  is a top plan view of a mobile interactive presentation and collaboration system according to an embodiment of the invention in which an Epson Model 450W projector is used in the system; 
         FIG. 5  is a front elevation view of the system of  FIG. 4 ; 
         FIG. 6  is a side elevation view of the system of  FIG. 4 ; 
         FIG. 7  is a top plan view of a mobile interactive presentation and collaboration system according to an embodiment of the invention in which an NEC Model WT610 projector is used in the system; 
         FIG. 8  is a front elevation view of the system of  FIG. 7 ; 
         FIG. 9  is a side elevation view of the system of  FIG. 7 ; 
         FIG. 10  is a top plan view of a mobile interactive presentation and collaboration system according to an embodiment of the invention in which an NEC Model U310W projector is used in the system; 
         FIG. 11  is a front elevation view of the system of  FIG. 10 ; 
         FIG. 12  is a side elevation view of the system of  FIG. 10 ; 
         FIG. 13  is a top plan view of a mobile interactive presentation and collaboration system according to an embodiment of the invention in which a Hitachi CP-AW250N projector is used in the system; 
         FIG. 14  is a front elevation view of the system of  FIG. 13 ; 
         FIG. 15  is a side elevation view of the system of  FIG. 13 ; 
         FIG. 16  is a top plan view of a mobile interactive presentation and collaboration system according to an alternative embodiment of the invention; 
         FIG. 17  is a front elevation view of the system of  FIG. 16 ; 
         FIG. 18  is a side elevation view of the system of  FIG. 16 ; 
         FIG. 19  is a photograph of the rear side of the projection screen of an embodiment according to  FIG. 1 ; and 
         FIG. 20  is a photograph of the front side of the projection screen of an embodiment according to  FIG. 1 . 
     
    
    
     While the present invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the present invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention. 
     DETAILED DESCRIPTION 
     As depicted in  FIGS. 1-3 , a mobile interactive presentation and collaboration system  30 , according to an embodiment of the present invention, comprises a cart chassis  32 , a projector carriage  34 , a rear projector  36  and a screen assembly  38 . The cart chassis  32  comprises an elongated front member  40  and at least two side members  42  projecting rearwardly from the ends of the front member  40 . As depicted in  FIGS. 1, 4, 7, 10 and 13 , in certain embodiments, the side members  42  extend in parallel rearward from the front member  40  and angled at about ninety degrees to the front member  40 . As depicted in  FIG. 21 , in certain embodiments, the side members  42  is positioned at about a forty five degree angle relative to the front member  40 . In various embodiments, the side members  42  can be angled at a plurality of different angles less than ninety degrees relative to the front member  40  to prevent tipping of the carriage  34  in both an both a fore and aft direction (denoted in  FIG. 3  with the arrow annotated “z-z”) and in a lateral direction (denoted in  FIG. 3  with the arrow annotated “x-x”). 
     In certain embodiments, the cart chassis  32  also comprises a plurality of wheels  44  positioned beneath the front member  40  and the side members  42  allowing the cart chassis  32  to be maneuvered. As depicted in  FIGS. 2-3, 5-6, 8-9, 11-12 and 14-15 , the wheels  44  can be positioned at the ends of the side members  42  such that the wheels  44  are arranged in a generally rectangular arrangement. In certain embodiments, the wheels  44  can comprise wheel locks for fixing the cart chassis  32  once the cart chassis  32  is positioned in a desired position. In other embodiments, the can chassis  32  can comprise other conventional support elements for supporting the cart chassis  32  including, but not limited to fixed legs, adjustable height legs, toot pads, to friction sliding pads and other conventional mean of supporting and/or moving the cart chassis  32  without tipping the cart chassis  32 . 
     As depicted in  FIGS. 1, 3-4, 6-7, 9-10, 12-13, 15-16 and 18 , the projector carriage  34  defines a generally horizontal shelf for receiving the projector  32 . As depicted in  FIGS. 7 and 9 , in certain embodiments, the projector carriage  34  extends rearward from the front member  40  of the cart chassis  32 . In this configuration, the projector carriage  34  is aligned with or proximate to the horizontal plane defined by the side members  42  of the cart chassis  32 . As depicted in  FIGS. 1, 3-4, 6, 10, 12-13, 15-16 and 18 , in certain embodiments, the projector carriage  34  extends rearward from the screen assembly  38 . In this configuration, the projector carriage  34  is positioned at or proximate to the bottom most portion of the screen assembly  38  such that the projector carriage  34  is proximate to the cart chassis  34 . 
     Projector  36  may be any suitable short throw projector available on the market. As can be seen, these projectors can enable system  30  to accommodate different aspect ratio projected images, for example 16:9, 16:10 ad 4:3, with appropriate adjustment of the projector position relative to screen assembly  38 . In addition to the examples provided, it will be appreciated that any other suitable projection device can be used in system  30  with the appropriate positioning and aspect ratio adjustment. 
     In certain embodiments, the projector carriage  34  comprises an adjustment assembly allowing the projector carriage  34 , and correspondingly the projector  36 , to be moved vertically (denoted in  FIG. 3  with the arrow annotated “y-y”), in the fore and aft direction and in the lateral direction. The adjustment assembly can comprise but is not limited to a hydraulic system, worm gear assembly, a plurality of engagement points spaced vertically and/or laterally to which the projector carriage  34  can be releasably attached and other conventional means of positioning and fixing the projector carriage  34 . 
     As depicted in  FIGS. 1-18 , the screen assembly  38  comprises a pair of side supports  46  and rear projection screen  48  having a front face and a rear face. In certain embodiments, the side supports  46  extend vertically from the side members  42  of the cart chassis  32 . In this configuration, the side supports  46  are positioned such that side supports  46  are aligned with or proximate to the front member  40  of the cart chassis  32 . Alternatively, the side supports  46  extend vertically from the ends of the front member  40  of the cart chassis  32 . In certain aspects, the side supports  46  position the rear projection screen  48  such the rear projection screen  48  is positioned a predetermined distance above the cart chassis  32  to define a gap between the bottom of the rear projection screen  48  and the cart chassis  32 . In an embodiment as depicted in  FIGS. 1-3 , and  19 - 20 , rear projection screen  48  can comprise a tempered glass pane  50  presenting a front side  52  and a rear side  54 . A suitable white or light colored projection material, for example Dual-Vision white vinyl projection screen material available from Da-Lite Screen Company of Warsaw, Ind. is applied to the rear side  54 . It will be appreciated that any other suitable rear projection screen material may be substituted and applied to the rear side  54 . It will also be appreciated that another suitable transparent material may be substituted for the tempered glass pane  50 , such as polycarbonate or other acrylic material. 
     Typically, the primary consideration for the projected image is the diagonal screen size. As shown in  FIGS. 3, 6, 9, 12 and 15  and the tables below, the projection distance A, the offset distance B and offset distance C can each be varied by adjusting the relative positioning of the projector carriage  34  via the adjustment assembly to provide a projected image having the desired diagonal screen size. For the purposes of this disclosure, the projection distance A is the horizontal distance from the center of the projector lens to the rear face of the rear projection screen  48 . The offset distance B is vertical distance from the bottom of the projector to the desired bottom edge of the projected image for the purposes of this disclosure. Similarly, the offset distance C is the vertical distance from the bottom of the projector to the desired top edge of the projected image. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Representative distances at which the projector carriage 34 can be positioned to provide 
               
               
                 a desired screen size at a 16:9 aspect ratio 
               
             
          
           
               
                 Screen Size (diagonal) 
                 Projection distance A 
                 Offset Distance B 
                 Offset distance C 
               
               
                   
               
             
          
           
               
                 60 inches 
                 19 to 26  
                 inches 
                 8.8 to 16.1 
                 inches 
                 38.2 to 52.1  
                 inches 
               
               
                 65 inches 
                 21 to 28  
                 inches 
                 9.7 to 17.6  
                 inches 
                 41.6 to 56.6  
                 inches 
               
               
                 70 inches 
                 About 22  
                 inches 
                 About 10.6  
                 inches 
                 About 44.9  
                 inches 
               
               
                 80 inches 
                 About 26  
                 inches 
                 About 12.4  
                 inches 
                 About 51.6  
                 inches 
               
               
                 90 inches 
                 About 29  
                 inches 
                 About 14.2  
                 inches 
                 About 58.3  
                 inches 
               
               
                 93 inches 
                 About 30  
                 inches 
                 About 14.7  
                 inches 
                 About 60.3 
                 inches 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Representative distances at which the projector carriage 34 can be positioned to provide 
               
               
                 a desired screen size at a 16:10 aspect ratio 
               
             
          
           
               
                 Screen Size (diagonal) 
                 Projection distance A 
                 Offset Distance B 
                 Offset distance C 
               
               
                   
               
             
          
           
               
                 60 inches 
                 15.6 to 25 
                 inches 
                 6.9 to 15.6 
                 inches 
                 38.7 to 54 
                 inches 
               
               
                 70 inches 
                 18.3 to 29 
                 inches 
                 8.4 to 18.5 
                 inches 
                 45.5 to 59.4 
                 inches 
               
               
                 77 inches 
                 About 20 
                 inches 
                 About 13 
                 inches 
                 About 54 
                 inches 
               
               
                 80 inches 
                 20 to 25 
                 inches 
                 6.5 to 14.5 
                 inches 
                 48.5 to 59 
                 inches 
               
               
                 85 inches 
                 About 22 
                 inches 
                 About 14 
                 inches 
                 About 60 
                 inches 
               
               
                 87 inches 
                 About 22 
                 inches 
                 About 14 
                 inches 
                 About 60 
                 inches 
               
               
                 90 inches 
                 23 to 28 
                 inches 
                 11.4 to 16 
                 inches 
                 55.5 to 63.7 
                 inches 
               
               
                 96 inches 
                 24 to 30 
                 inches 
                 12.3 to 16 
                 inches 
                 58 to 66 
                 inches 
               
               
                 100 inches  
                 25 to 26.3 
                 inches 
                 16 to 17.5 
                 inches 
                 69 to 70.5 
                 inches 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Representative distances at which the projector carriage 34 can be positioned to provide 
               
               
                 a desired screen size at a 4:3 aspect ratio 
               
             
          
           
               
                 Screen Size (diagonal) 
                 Projection distance A 
                 Offset Distance B 
                 Offset distance C 
               
               
                   
               
             
          
           
               
                 55 inches 
                 19 to 26  
                 inches 
                 7.3 to 16.3  
                 inches 
                 40.3 to 49.3  
                 inches 
               
               
                 60 inches 
                 21 to 29  
                 inches 
                 8.1 to 17.9  
                 inches 
                 44.1 to 53.9  
                 inches 
               
               
                 63 inches 
                 18 to 25  
                 inches 
                 3.7 to 12.3  
                 inches 
                 41.5 to 50.1  
                 inches 
               
               
                 70 inches 
                 23 to 25  
                 inches 
                 About 9.8  
                 inches 
                 About 51.8  
                 inches 
               
               
                 80 inches 
                 26 to 28  
                 inches 
                 About 11.5  
                 inches 
                 About 59.5  
                 inches 
               
               
                 85 inches 
                 About 30  
                 inches 
                 About 12.3  
                 inches 
                 About 63.3  
                 inches 
               
               
                   
               
             
          
         
       
     
     As depicted in  FIGS. 5, 8, 11, and 14 , in certain embodiments, the rear projection screen  48  can comprise about five feet, six inches wide by about six feet high, wherein the image projected by the projector  36  is on less than the entire area of rear projection screen  48 . In other embodiments, the dimensions of the rear projection screen  48  can be varied according to the needs of the consumer and physical constraints such as the dimensions of doors, elevators and hallways through which the system  30  must be navigated. In certain embodiments, the side members  42  of the chassis cart  32  can be at least fifteen inches in length. In other embodiments, the side members  42  can be at least twenty inches in length. In other embodiments, the side members  42  can be at least twenty five inches in length. Accordingly, in certain embodiments, the side members  42  can be less than forty percent of the length of the side supports  46 . In other embodiments, the side members  42  can be less than thirty percent of the length of the side supports  46 . In other embodiments, the side members  42  can be less than twenty five percent of the length of the side supports  46 . In certain aspects, the projected image can comprise about five fee, four inches wide and about three feet high. In certain embodiments, the projected image can comprise less than seventy percent of the total area of the rear projection screen  48 . In other embodiments, the projected image can comprise less than sixty percent of the total area of the rear projection screen  48 . In other embodiments, the projected image can comprise less than fifty percent of the total area of the rear projection screen  48 . In other embodiments, the projected image can comprise less than forty percent of the total area of the rear projection screen  48   
     In operation, the projector  36  may be mounted on projector carriage  34  and appropriately adjusted so as to produce an image of a desired aspect ratio projected onto rear side  54  of screen  48 . The image is visible from the front side  52  of the screen  48 . In certain embodiments, the surface of the pane  50  can be annotated with dry erase or other markers without affecting the screen material on rear side  54 . In addition, with the positioning of appropriate sensors on screen assembly  38  and/or cart chassis  32 , system  30  may be fully interactive, enabling annotations made on screen  48  to be recorded, and enabling any other such interactive features as are known for use with interactive short throw projection systems. 
     As depicted in  FIGS. 16-17 , in certain embodiments, the system  30  can further comprise at least one rear enclosure panel  60  enclosing and making the projector carriage  34  and the projector  36 . Each rear enclosure panel  60  is positioned to project vertically from the side member  42  of the cart chassis  32 . In certain embodiments, the cart chassis  32  can further comprise a rear member  62  for linking the ends of the side members  42  opposite the front member  40 . 
     The foregoing descriptions present numerous specific details that provide a thorough understanding of various embodiments of the invention. It will be apparent to one skilled in the art that various embodiments, having been disclosed herein, may be practiced without some or all of these specific details. In other instances, components as are known to those of ordinary skill in the art have not been described in detail herein in order to avoid unnecessarily obscuring the present invention. It is to be understood that even though numerous characteristics and advantages of various embodiments are set forth in the foregoing description, together with details of the structure and function of various embodiments, this disclosure is illustrative only. Other embodiments may be constructed that nevertheless employ the principles and spirit of the present invention. Accordingly, this application is intended to cover any adaptations or variations of the invention. 
     For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of 35 §112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.