Abstract:
A colored light filter for providing a single colored light upon light being transmitted thereto and including a lamination of an at least substantially clear plastic material provided with colored dye and an at least substantially clear thermosetting material. A manufacturing process for laminating an at least substantially clear plastic material provided with colored dye and an at least substantially clear thermosetting material together to provide the color light filter.

Description:
BACKGROUND OF THE INVENTION 
     Color light filters are known to the art for providing a single color of light, or at least a substantially single color of light, upon a plurality of colors of light in the visible light spectrum being transmitted thereto. The color of light provided is, of course, dependent upon the color of the color light filter. Such color light filters are widely used in the entertainment field, such as for example, in stage theaters, outdoor shows and other applications where relatively bright colored light is desired or required. The light for such applications transmitted to the color light filter is typically from what is referred to in the art as a white light source, or reflected from a white light source, and which white light source typically includes at least a portion of the colors of light in the visible light spectrum from violet, through blue, through green, through yellow-orange to red. Some white light sources also produce at least some ultraviolet light and, of course, upon such white light source becoming heated, the white light source radiates and produces at least some infrared light. Light is also used herein and in the appended claims as radiation, electromagnetic radiation, or energy that can affect the human eye. 
     As is further known to the color light filter art, and referring to FIG. 1A, the typical prior art color light filter includes a transparent, or least substantially transparent, base plastic material  18  which has either or both of its outer surfaces suitably coated with a colored dye  19  in the manner known to the art, or which base material  18  can have a colored dye diffused into either or both of its outer surfaces in a manner known to the art, or and referring to FIG. 1B, the base material  18 A can have colored dye  19  dispersed completely through the base material  18 A in the manner known to the art. Such prior art plastic base material  18  and  18 A may be a clear, or least substantially clear thermoplastic material such as polycarbonate, vinyl, or acetate or may be a thermosetting material such as polyester. 
     A typical prior art color light filter  10  and its implementation are illustrated diagrammatically in FIG.  1 . The prior art color light filter  10  is mounted in a suitable holder (not shown) in front of a light source  12  which may be, for example, the above-noted white light source. Light illustrated by the arrows identified by general numerical designation  14  is transmitted to the color filter  10  from the light source  12  and, for example, upon the color light filter  10  being provided with red dye as described above, the color filter  10  will be a red color light filter, and the red color light filter will allow red color light  16  to pass therethrough but the red dye provided in the red color filter  10  will absorb and block all other colors of light in the visible light spectrum contained in the light  14  from passing through the red color light filter. 
     Referring again to FIG. 1, the light source  12  is typically operated in the above-noted applications at 500 watts or above and upon the colored dye contained in the base material, as noted above, absorbing the colors of light as noted to prevent their passage through the color filter, heat is produced which can be sufficient to cause the color light filter  10  to degrade, lose its strength or structural integrity and fade. Such loss of strength, structural integrity or weakening can cause the color light filter  10  to wrinkle, or otherwise distort in shape, and fade thereby impairing, if not ultimately destroying, the ability of the color light filter  10  to produce a single color of light. This reduces the useful life of the color light filter  10  causing it to be replaced thereby increasing the cost of providing colored light. Further, in an application such as the above-noted theater application, the color light filter  10  may be located in a relatively inaccessible location in the theater which prevents the color light filter, upon weakening and fading as noted above, from being readily replaced such as during a theater production or performance. 
     Accordingly, there is a need in the color light filter for a new and improved color light filter having increased strength and an increased ability to withstand heat and maintain its structural integrity thereby providing the light filter with an increased useful life span. There is a further need in the art for a process of manufacturing such new and improved color light filter. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to satisfy the foregoing needs in the color light filter art. 
     A color light filter satisfying the foregoing need and embodying the present invention may include a layer of substantially clear plastic material provided with colored dye of a selected color and for allowing light of the selected color to pass therethrough and the colored dye for absorbing and blocking the passage therethrough of light other than the selected color of light in the visible spectrum of light; and 
     a layer of clear thermosetting material laminated to the layer of substantially clear plastic material and for providing the layer of substantially clear plastic material with strength upon the layer of substantially clear plastic material becoming heated due to the colored dye absorbing light of the other colors of light. 
     The process of the present invention for manufacturing the color light filter of the present invention, and satisfying one of the foregoing needs in the art, may include the steps of providing a substantially clear layer of plastic material provided with a colored dye, providing a layer of clear thermosetting material, and laminating the layer of substantially clear plastic material provided with the colored dye to the layer of clear thermosetting material to provide the color light filter. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatical illustration of a typical prior art color light filter and its implementation; 
     FIG. 1A is a diagrammatical illustration of a prior art color filter including a clear, or substantially clear, base material having colored dye coated or diffused into one or both of its outer surfaces; 
     FIG. 1B is a diagrammatical illustration of a prior art color filter including a clear, or substantially clear, plastic base material having a dye dispersed therethrough; 
     FIG. 2 is a perspective view of a color light filter embodying the present invention; 
     FIG. 3 is a diagrammatic illustration of the manufacturing process of the present invention for manufacturing the color light filter of the present invention; and 
     FIG. 4 is a diagrammatical cross-section view of the laminate produced by the manufacturing process of FIG. 3 taken in the direction of the arrows  4 — 4  in FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 2, a color light filter embodying the present invention is illustrated and identified by general numerical designation  20 . The color light filter  20  may include a layer of material  21  which may be the layer of clear, or at least substantially clear, plastic material  18  shown in FIG. 1A having either or both of its outer surfaces coated with a colored dye, or having a colored dye diffused into either or both of its outer surfaces, or the layer of material  21  may be the clear, or at least substantially clear, layer of plastic material  18 A shown in FIG. 1B having a colored dye dispersed therethrough. The clear, or at least substantially clear, plastic material  18 , of FIG. 1A, or  18 A of FIG. 1B, as noted above, may be either a thermoplastic material such as vinyl, acetate or polycarbonate or may be a thermosetting material such as polyester. The layer of material  21 , of FIG. 2, is laminated to a layer of clear, or at least substantially clear, thermosetting material  22  which may be, for example, at least substantially clear polyester. The layers are laminated by suitable heat and pressure, as described in detail below, utilizing a clear, or at least substantially clear, suitable adhesive  23 , which may be a pressure-sensitive acrylic adhesive or another suitable clear, or at least substantially clear, heat-stable adhesive. 
     Referring now to the process of the present invention for manufacturing the color light filter  20  of FIG. 2, reference is made to FIG. 3. A layer or material  21 , as shown in FIG.  2  and as described above, is fed from a suitable supply  26  thereof, a layer of suitable clear thermosetting material  22 , such as the above-noted at least substantially clear polyester, is fed from a suitable supply  30  thereof, and clear adhesive, of the types noted above, are fed forwardly as illustrated in FIG. 3 between a pair of opposed and heated pressure rollers  34  and  36 . The opposed heat and pressure rollers  34  and  36  apply heat and pressure, for example pressure in the range of from about 2 to about 3 psi and heat at about room temperature or about 78° F., to the layer of material  21 , the layer of clear thermosetting material  22  and the intermediate layer of clear adhesive  23  to laminate the material  21  and the clear thermosetting material  22  together as indicated by general numerical designation  38  in FIG.  3 . 
     The lamination  38  may thereafter be cut into suitable color light filters  20 , FIG. 2, by suitable cutting machinery of the type known to the art. 
     It will now be presumed that the color light filter  20  of the present invention is placed in a suitable holder and resides in place of the prior art color light filter  10  of FIG.  1 . It will be understood that the colored dye provided in the material  21 , FIG. 2, will be selected to be of a color of one of the colors of light included in the plurality of colors of light  14  shown in FIG.  1 . The clear, or at least substantially clear, plastic material comprising the layer of material  21  (FIG.  2 ), will allow the selected color of light to pass through the color filter  20  of the present invention and, the color dye provided in the material  21  will absorb and thereby block the non-selected colors of light included in the light  14  from passing through the color filter  20  which will produce heat and tend to cause the layer of material  21  (FIG. 2) to lose its strength, weaken, and otherwise distort in shape as noted above, however, since the layer of material  21  is laminated to the layer of thermosetting material  22  (FIG. 2) as taught above with regard to the manufacturing process of FIG. 3, the layer of clear thermosetting material  22 , since it is thermosetting and not thermoplastic, will retain its shape and strength and, by being laminated to the layer of material  21 , the layer of thermosetting material  22  will cause the layer of material  21  to maintain its shape and structural integrity while it is heated and hence the life span of a color light filter  20  of the present invention will be increased beyond that of the prior art color light filter  10  of FIG.  1 . 
     It will be further understood that in accordance with the further teachings of the present invention, the clear plastic adhesive  23  (FIG. 2) may be provided with suitable ultraviolet inhibitor for inhibiting any ultraviolet light that may be present in the light  14  (FIG. 1) from passing through the clear adhesive  23  which in turn reduces the amount of heat absorbed by the colored dye in the material  21 . This reduction in absorbed heat reduces, or at least retards, the loss of strength of the material  21  and further enhances the life span of a color light filter  20  of the present invention. 
     It will be understood by those skilled in the art that many variations and modifications may be made in the present invention without departing from the spirit and scope thereof.