Abstract:
In varying embodiments, the present invention incorporates a combination of structures suitable for providing a lightweight and portable projection surface. In certain embodiments, the present invention includes a frame having four beams connected at the corners, with a collapsible brace at each corner, so that the frame can be collapsed for storage or transport. In certain embodiments, each beam may incorporate one or more collapsible inline braces in order to promote an even more compact profile when collapsed.

Description:
[0001]     This application claims priority to U.S. application Ser. No. 60/388,181 filed on Jun. 11, 2002. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates generally to media presentation, and specifically to a compact and highly-portable projection screen.  
         [0003]     Mobile projection screens were first developed in the late 1950s and early 1960s as an alternative to the large format roller-type projection screens, which operated in the manner of a pull-down window shade. Although roller screens are somewhat portable in small sizes, there was and is a demand for larger size projection screens for use by staging and projection professionals in remote locations for events such as sales meetings, seminars, and entertainment.  
         [0004]     Users needing a projection screen that was, for example, 14′ long, which is not an uncommon size, would require a one-piece screen in a 14′ long tube. A roller screen of this size was expensive to manufacture and difficult to ship and handle on-site in a temporary, non-permanent application.  
         [0005]     As a consequence of the drawbacks found in the roller screens, an alternative product was developed using a frame constructed of 1″ aluminum tube stock. The aluminum tube stock was cut in various lengths as required and a hinge was added. This hinge allowed the product to be folded into a smaller size, which could be assembled (unfolded) and disassembled (folded) as needed.  
         [0006]     With this design, the user attached a PVC vinyl projection surface to the frame using matching male and female snaps, which were applied to both the folding frame and the folding PVC vinyl projection surface. This design reduced time of assembly in the field and reduced the overall shipping dimensions, which reduced the overall cost to provide professional projection at remote locations.  
       SUMMARY OF THE INVENTION  
       [0007]     The mobile projection screen disclosed herein provides a unique combination of structures suitable for use with all forms of projection equipment. Using the teachings of the present invention, one of skill in the art will be able to readily construct a strong, lightweight projection screen able to be compactly stored and transported and easily assembled.  
         [0008]     In one embodiment, the present invention includes a projection screen frame having a top beam, a bottom beam, and at least one connecting beam connecting the top beam to the bottom beam. Each beam is connected to each beam adjacent to it by a brace, having a pivot pin disposed in one of the adjacent beams, a pivot plate disposed to pivot around the pivot pin, one or more fasteners connecting the pivot plate to the remaining beam, and a connecting brace, connecting the adjacent beams.  
         [0009]     In a second embodiment, the present invention includes a projection screen frame having a top beam, a bottom beam, and two side beams connecting the top beam to the bottom beam. Each beam is connected to each beam adjacent to it by a corner brace, having a pivot pin disposed in one of the adjacent beams, a pivot plate disposed to pivot around the pivot pin, one or more fasteners connecting the pivot plate to the remaining beam, and a connecting brace connecting the beams at points inside the pivot point. At least one beam has a pivotable inline brace disposed therein, separating the beam into two adjacent beam portions. The inline brace includes a pivot pin disposed in one of the adjacent beam portions, a pivot plate disposed to pivot around the pivot pin, one or more fasteners connecting the pivot plates to the remaining beam portion, and a latch, operable to latch the adjacent beam portions in an inline configuration.  
         [0010]     In a third embodiment, the present invention comprises projection screen frame having a top beam, a bottom beam, and two side beams connecting the top beam to the bottom beam. Each beam is connected to each beam adjacent to it by a corner brace comprising a pivot pin disposed in one of the adjacent beams, a pair of pivot plates disposed to pivot around the pivot pin, one or more fasteners fixing the orientation of the pivot plates to the remaining beam, and a connecting brace connecting the beams at points inside the pivot point. At least one beam has a pivotable inline brace disposed therein, separating the beam into two adjacent beam portions. The inline brace includes a pivot pin disposed in one of the adjacent beam portions, a pair of pivot plates disposed to pivot around the pivot pin, one or more fasteners fixing the orientation of the pivot plates to the remaining beam portion, and a latch, operable to latch the adjacent beam portions in an inline configuration.  
         [0011]     In a fourth embodiment, the present invention includes a projection screen frame having a top beam, a bottom beam, and two side beams connecting the top beam to the bottom beam. Each beam is connected to each beam adjacent to it by a corner brace having a pivot pin disposed in one of the adjacent beams, a pair of pivot plates disposed to pivot around the pivot pin, one or more fasteners fixing the orientation of the pivot plates to the remaining beam, and a connecting brace connecting the beams at points inside the pivot point. Each beam has at least one pivotable inline brace disposed therein, separating the beam into two adjacent beam portions. The inline brace has a pivot pin disposed in one of the adjacent beam portions, a pair of pivot plates disposed to pivot around the pivot pin, one or more fasteners fixing the orientation of the pivot plates to the remaining beam portion, and a latch, operable to latch the adjacent beam portions in an inline configuration. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     For more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying Figures.  
         [0013]      FIG. 1  depicts a three-dimensional view of an assembled projection screen according to one embodiment of the present invention;  
         [0014]      FIG. 2  depicts a front view of a locked corner brace of a mobile projection screen according to one embodiment of the present invention;  
         [0015]      FIG. 2A  depicts a rear view of an unlocked corner brace of a mobile projection screen according to one embodiment of the present invention;  
         [0016]      FIG. 3  depicts a three-dimensional view of an unlocked inline brace according to certain embodiments of the present invention;  
         [0017]      FIG. 4  depicts a three-dimensional view of a locked T-brace according to certain embodiments of the present invention; and  
         [0018]      FIG. 4A  depicts a three-dimensional view of an unlocked T-brace according to certain embodiments of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that may be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments.  
         [0020]      FIG. 1  depicts a three-dimensional view of an assembled projection screen according to one embodiment of the present invention. As seen in  FIG. 1 , mobile projection screen assembly  100  includes a projection surface  102  mounted on a rectangular frame  104 . The frame  104  is, in turn, affixed to a pair of mounts  106 , each of which incorporates a vertical strut  108  and a horizontal base  110 . In this embodiment, the frame  104  is connected to the mounts  106  at pivot points  112 . The angle of the frame  104 , and therefore the screen  102 , with respect to the vertical struts  108  can be adjusted and fixed using adjustment mechanism  114 .  
         [0021]     Stability, weight and transport volume are all closely interrelated. To optimize packing dimensions, the frame  104  can be made from a number of different tube sizes. At least one embodiment uses tubing having a profile of 32 mm×32 mm square in cross-section. In certain embodiments, this tubing is extruded aluminum alloy with a weight of 0.6 kg/m. The 32 mm×32 mm profile tubing has been found suitable for all screen sizes up to at least 400×400 cm, 600×300 cm or 900×300 cm.  
         [0022]     In another embodiment, the frame  104  is constructed of tubing having a cross-section of 64×32 mm. This tubing has been used successfully in frames as large as 500×340 cm and up. This size of tubing can also, of course, be used in smaller frames if the application requires additional strength or rigidity.  
         [0023]     As explained in more detail below, Applicants have developed a novel way to integrate the corner braces of the frame  104  into the interior of the frame  104 , rather than attaching it externally, as found in the prior art. This innovation has proved to be a significant enhancement to the overall performance of the device. This feature also facilitates the use of a folding projection surface  102  with square corners. This further enhances the performance of the device.  
         [0024]     A second innovation of the present invention is the incorporation of pressure release push button self-latching inline hinges. Prior to Applicant&#39;s development and incorporation of this feature, the prior art used a locking hinge requiring at least two hands to latch in place. In certain embodiments, the frame  104  is designed to lock its hinges in place automatically as the frame  104  is pulled open. Using the novel aspects disclosed herein, a user can assemble and disassemble certain embodiments of frame  104  without any tools.  
         [0025]      FIG. 2  depicts a front view of a locked corner brace of a mobile projection screen according to one embodiment of the present invention.  FIG. 2A  depicts a rear view of an unlocked corner brace of a mobile projection screen according to one embodiment of the present invention.  
         [0026]     Corner brace  200  is composed of a first beam  202  joined to a second beam  204  by a pivot pin  206  and a joint plate  208 . Joint plate  208  is fastened to second beam  204  by fasteners  210 . First beam  202  and second beam  204  are connected and reinforced by over-center brace  212  which is connected to first beam  202  by fastener  214 , and to second beam  204  by fastener  216 .  
         [0027]     In certain embodiments, one or both of beams  202  and  204  of joint  200  may have a slot cut in the inside face of each, so as to accommodate the over-center brace  212  when the corner joint  200  is collapsed. In certain embodiments, one face of the beams  202  and  204  may incorporate snaps to facilitate attachment of a projection screen  102 .  
         [0028]      FIG. 3  depicts a three-dimensional view of an unlocked inline brace according to certain embodiments of the present invention. Inline brace  300  connects a first beam  302  and a second beam  304 , allowing them to pivot about pivot pin  306  unless latched.  
         [0029]     First beam  302  and second beam  304  are connected to pivot pin  306  by inner latch plates  308  and outer latch plates  310 , respectively. Inner latch plates  308  are connected to beam  304  by fasteners  314 . Outer latch plates  310  are attached to beam  302  by fasteners  312 .  
         [0030]     In storage, the inline brace  300  will be left free to pivot about pivot pin  306  and will not be latched. In use, however, the inline brace  300  can be latched into a straight configuration, so that beam  302  and beam  304  are generally parallel and aligned to one another. This latching is accomplished using inner latch  316  and outer latch  318 , which are designed to mate together and latch upon engagement. In certain embodiments, one or both of inner latch  316  and outer latch  318  may be spring-loaded. In certain embodiments, inner latch  316  and outer latch  318  are designed to automatically latch whenever beam  302  and beam  304  are aligned sufficiently to engage inner latch  316  and outer latch  318 .  
         [0031]      FIG. 4  depicts a three-dimensional view of a locked T-brace according to certain embodiments of the present invention.  FIG. 4A  depicts a three-dimensional view of an unlocked T-brace according to certain embodiments of the present invention.  
         [0032]     T-brace  400  connects central beam  402  to first transverse beam  404  and second transverse beam  406  through pivot pins  408  and  410 , respectively. Pivot pins  408  and  410  are connected to transverse beams  404  and  406  by pivot plates  412  and  414  respectively. Pivot plates  412  and  414  are secured to transverse beams  404  and  406  by fasteners  416  and  418 .  
         [0033]     T-brace  400  is supported and stiffened by locking braces  420  and  422 . Locking brace  420  braces the connection between central beam  402  and first transverse beam  404 , while locking brace  422  braces the connection between central brace  402  and second transverse brace  406 . In certain embodiments, either or both of locking braces  420  and  422  may be over-center locking braces.  
         [0034]     Locking brace  420  is connected to transverse beam  404  by fastener  424  and to central beam  402  by fastener  428 . Similarly, locking brace  422  is connected to transverse beam  406  by fastener  426  and to central beam  402  by fastener  428 . In certain embodiments, central beam  402 , transverse beam  404 , and/or transverse beam  406  may incorporate a slot or pocket to accommodate the locking braces in the closed position.  
         [0035]     While this invention has been described in reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments.