Abstract:
Articulated display matrix apparatus for providing moving or flashing variable messages is disclosed. The apparatus is highly adaptable and portable. Because the linear arrays of display cells are durably enclosed, as well as articulated, they can shipped and stored compactly. Because of their light weight and their highly-flexible structure they can be mounted in a variety of configurations and on a variety display panel shapes, without tools. The display matrix arrays can provide a continuous combined display matrix that is extensible in two dimensions.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to message display matrixes. More particularly, the present invention pertains to portable message display matrixes. 
     2. Discussion of Related Art 
     Point-of-sale advertising boards and convention booth advertising frequently use alphanumeric matrixes that provide moving or flashing displays of variable messages to attract and secure the attention of passers-by. The display matrixes must be adaptable, to satisfy changing design requirements. Both the display matrixes and the structural units supporting them must be readily portable. 
     When the display matrixes are integral with the board or the booth that supports them, the structural units become bulkier, and more awkward to ship and to store. In particular, the size of the units that support the display matrixes makes it difficult to protect those matrixes, and the weight of the units makes it difficult to prevent them from damaging display matrixes on adjacent units during shipping. 
     SUMMARY OF THE INVENTION 
     Display matrix apparatus in accordance with the present invention includes first and second display cells. Each cell has a display plane, a hinge having a hinge axis, and a respective light-weight enclosure. The enclosures each have an angled side that permits rotation of the cells in the articulated matrix about the hinge with a reduced separation between the cells. 
     In particular embodiments, the angled side defines an oblique plane that forms an acute angle with a plane parallel to the display plane at the hinge axis. 
     In one embodiment, the angled side defines an oblique plane forward of the hinge axis, such that the cells in the articulated matrix can rotate forward about the hinge axis without damaging display elements on the display plane. 
     In a preferred embodiment, the backwall and angled sides of the enclosures are made from a light-weight metal sheet. The angled sides of the enclosures are partially open. This provides a very light-weight enclosure and permits cables electrically connecting the repective display planes to move freely when the enclosures are rotated about the hinge axis, without pinching the cables. 
     The light-weight, articulated construction of apparatus in accordance with the present invention permits a hook fabric to quickly and reliably attach the apparatus to napped fabric surfaces having a wide variety of shapes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the present invention will be better understood when the detailed description of a preferred embodiment given below is considered in conjunction with the drawings provided, wherein: 
     FIGS. 1 and 1a are a plan view of an array of hinged display cells viewed from above, and a detail of that plan view showing a cell cut out of the center of the array, respectively; 
     FIG. 2 is a schematic cross-section view of a single display cell taken perpendicular to the display face and parallel to the hinge axes of the display cell enclosure; 
     FIG. 3 shows a flexible message display matrix in accordance with the present invention mounted in an advertising booth; and 
     FIG. 4 shows a message display matrix in accordance with the present invention compactly coiled in a carrying case. 
    
    
     In these figures, similar reference numerals indicate similar structures. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a linear array of display cells 10 in accordance with the present invention. A first display cell 10a is attached to the next display cell 10b by a tough, continuous plastic web 11 having a hinge axis 12a. The array provides an easy-to-use, highly-adaptable apparatus for producing electronically-controlled variable messages suitable for portable displays used in point-of-sale advertising and convention booths. 
     The display cells in FIG. 1 are flexed about hinge axes 12a through 12d to position adjacent display planes 14 of the cells 10 at a shallow convex oblique angle (12a), 45-degree concave angles (12b) and (12c), and a 90-degree convex angle (12d), respectively. This articulation makes the message display apparatus highly adaptable. It can be compactly stored, and is conformable to the curves and corners on irregular display surfaces, such as the one shown in FIG. 3. 
     Between the backwall 16 of the cell 10 and the hinge axis 12, a rear portion 22 of the side of each enclosure 18 is cutaway or angled so as to define a first oblique plane 23 extending aft of and including the hinge axis 12. This oblique plane 23 intersects a plane 24 that includes the hinge axis 12 and is perpendicular to the display plane 14, at an angle &#34;x&#34; of 45 degrees. 
     The front portion 26 of each enclosure 18, likewise, is angled and defines a second oblique plane 27 including the hinge axis 12. This second oblique plane 27 intersects the perpendicular plane 24 at an angle &#34;y&#34; that is one-half the size of angle &#34;x&#34;. This forward cutaway permits the distance between cells 10 at the hinge axis 12 to be minimized, without interfering with the rotation of each cell through 135 degrees relative to the next. 
     As shown more clearly in FIG. 1a, a rectangular array of equidistant light-emitting diodes (LEDs) 28 is affixed to a printed circuit board 30. The circuit board 30 is parallel to the display plane 14 defined by the forward ends of the display elements 28 in each cell 10. When the circuit boards 30 are aligned so that the respective display planes 14 are co-planar, forming a 180 degree angle with each other, the distance between adjacent first and second LEDs 28b and 28a on one circuit board 30a is the same as the distance between adjacent LEDs 28b and 28c on the respective circuit board 30b across the hinge axis 12a. This element spacing provides a linear array of cells having a combined display matrix that appears to be continuous. 
     The circuit board 30c is electrically linked to the circuit boards 30b and 30d in adjacent cells 10b and 10d by respective flexible flat cables 32b, 32c. The cables 32 pass through openings 31 in the side walls 33 of the respective cells 10. The openings 31 allow free movement of the cables, preventing cables such as the cable 32d from becoming pinched when the cells 10d and 10e are rotated to mount them on the convex right angle 50 shown in FIG. 3. This permits cables electrically connecting the repective cells to move freely when the cells are rotated about the hinge axis. 
     Preferrably, the respective open angled back portions 22 of the tubular enclosures 18 on each side of a given hinge axis 12 are partially enclosed by sidewalls 33, to protect the circuit board from dirt, foreign objects, and static electricity. The sidewalls are made of thin, light-weight metal sheet that is contiuous with the backwall 16. The sheet is folded forward at a 45-degree angle along respective Sides of the backwall, but stop short of the hinge axis leaving a gap in the enclosure, behind the circuit board 30 which provides the opening 31 for free movement of the cables 32 between the respective enclosures 10. 
     Alternatively a thin, flexible one-piece web (not shown) made of a pliable poly-urethane may be attached with adhesive to the top and bottom extrusions 34 and the backwall 16 of each enclosure 18. This web would extend from one backwall 16a to the next 16b to flexibly seal larger openings 31, in place of the partially open sidewalls 33. Also, the cables 32 connecting the circuit boards 30 may be embedded in the flexible web hinge 11. The open sides of the enclosure may then be closed by metal or plastic sheets and the enclosures may be sealed by metal or plastic sheets. 
     The apparatus is particularly adaptable because it is light-weight enough to be attached to supporting structures by hook-and-loop fasteners. Specifically, the backwall 16 in the enclosure 18 of each cell 10 is covered by a strip of hook fabric 20 attached to the backwall by adhesive. 
     FIG. 2, is a section view taken along the section line 2--2 of the cell 10 shown in FIG. 1a. The enclosure 18 of each cell 10 is formed of two light-weight extruded metal sections 34 attached to the top and bottom of a bent sheet of light-weight metal that provides the backwall 16 and sidewalls 33 of the enclosure 18. The backwall 16 extends along the width of the adjacent edges of the respective extrusions 34, and is attached to right-angle surfaces 36 on the extrusions 34 by four fasteners 38. Preferably, the edges of the circuit board 30 are mounted with adhesive into a channel 39 in each extrusion 34. Alternately, they may be press-fit and crimped into the channel. The extension surfaces 36 and the channels 39 in the extrusion integrate the backwall 16 and circuit board 30 to form a stable, rigid box-like structure which can accomodate auxilliary circuit elements or auxilliary circuit boards including power regulators or power drivers, and microprocessor control circuits within the enclosure. 
     The extrusions 34 have cutaway portions 22, 26 aft and forward of each hinge axis 12, that reduce the separation between the cells 10 required to permit the cells to rotate through a 135-degree arc with respect to each other. The acute angle &#34;y&#34; forward of the hinge axes 12 also determines the minimum clearance that is provided between the display elements 28 of the respective cells 10 when the cells are rotated about a hinge axis toward each other, such as cells 10c and 10d on either side of hinge axis 12c. These cutaways 26 also permit extrusions 34 to extend forward of the circuit board 30, to protect the LEDs 28. 
     The extrusions 34 also have an overhang 40 that lies forward of the display plane 14. The overhang 40 cooperates with the cutaway portions 26 located forward of each hinge axis 12 to provide additional protection for the LEDs 28, as well as providing a cosmetic frame for the linear array. In particular, the overhangs 40 provide space between the LEDs 28 and the backwalls 16 of other cells 10, and the display elements 28 nearest the edges of each display plane 14 when the array is coiled about itself, as shown in FIG. 4. 
     In another embodiment, the cells are constructed without overhangs, so that the LED matrix extends the full height of the cell. Thus, areas otherwise covered by overhangs become part of the combined matrix. The articulated display matrix provided by this embodiment can be extended in two dimensions by stacking the linear arrays top to bottom, as well as end to end, and these stacked arrays also provide a continuous combined display matrix. 
     Specifically, if the distance between the top and bottom row of the elements and the respective near edge of each cell is one-half the distance between elements themselves, the combined display matrixes will be continuous between cells that are not hinged together, as well as along the length of the arrays. 
     Because of the light-weight construction of the enclosures 18, the hook fabric 20 securely attaches the cells 10 in the array 41 without requiring the use of tools. For example, FIG. 3 shows display arrays 41 mounted on the surface of an advertising booth 42 across the top of the napped fabric surface 44 that covers both the flat panel 46 and concave panel 48. The arrays could also be arranged vertically, or even diagonally, together or separately, on the panels 46, 48. 
     The flexible web hinge 11 permits the array 41 of cells 10 to conform to the convex right angle 50 between the panels 46, 48. The flexible web 11 also permits the array 41 to be mounted helically, about a column for instance. 
     The light-weight structure of apparatus in accordance with the present invention requires only minimal further protection from damage, thereby reducing the shipping weight and storage bulk of the arrays 41. In FIG. 4, for instance, an array 41 of cells 10 can be packed inside a simple carrying case 60 for shipping and storage, without additional cushioning. 
     It will be appreciated by one skilled in the art that variations and modifications of the disclosed apparatus are possible within the spirit and scope of this invention. For example, the enclosures could be formed of a sturdy plastic material by injection molding. 
     The embodiments described above are provided to illustrate presently preferred ways of making and using this invention. The invention is defined by the claims appended below.