Abstract:
A backlit sign is provided which utilizes a diffuser layer of numerous inks in a composition which allows the transmission of an illuminating source of light, but which substantially prevents the viewing of the source of light

Description:
[0001]    This application claims priority of U.S. provisional patent application Serial No. 60/318,588 having a filing date of Sep. 10, 2001 and is incorporated herein in its entirety by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to sign technology, and more specifically backlit visual displays which utilize unique compositions of inks and diffuser materials to distort the light source while providing sufficient illumination to display a sign or image.  
         BACKGROUND OF THE INVENTION  
         [0003]    The use of signs to display information, instructions, and advertisements are well known and are typically constructed by applying some form of ink, paint, or other material to a substrate backing material to identify lettering, graphics, directions, or other useful information. For nighttime applications, backlit signs have been provided which utilize a light source to illuminate a message or information to enhance the messages and desired sign information. These backlit signs are especially useful during low light conditions, although they are also used during daylight hours to enhance the sign image. One type of backlit sign commonly utilizes a light emitting diode (LED) source which provides light through one of a series of substrates or ink materials to illuminate an image or a message. One significant problem, however has been the inability of manufacturers and sign makers to create a sign which illuminates a message or other information, but which does not allow the light source to be seen by a viewer. Thus, often a “hot spot” of light can be seen which identifies the individual LEDs or other illuminating source, and which significantly distorts the image which is meant to be conveyed by the sign maker. Thus, there is a significant need in the art to provide a novel backlit sign which is capable of illuminating an image or message, but which obscures the light source which is positioned behind the sign or image. It is thus one aspect of the present invention to address this problem and to provide a method and apparatus which provides an improved backlit sign as set forth hereinbelow.  
         SUMMARY OF THE INVENTION  
         [0004]    It is thus one aspect of the present invention to provide a backlit sign manufacturing process and apparatus which prominently displays an image or information in an illuminated state, while not identifying the source of light which is projecting from a rearward portion of the sign. In one embodiment of the present invention, a process and composition is provided which includes utilizing a plurality of different inks and films applied to a substrate and which further includes a novel diffuser incorporating numerous types of inks which allow an image to be illuminated without identifying the light source. Thus, the present invention maybe utilized for any printed image applied on clear or translucent materials such as polycarbonates which are backlit by a light source and that offer some diffusion or moderation of light.  
           [0005]    It is another aspect of the present invention to utilize the diffusion inks and compositions in non-signage applications, such as overhead light sources, traffic lights, or on/off indicator lights which do not have any specific lettering or graphics displayed. Thus, the present invention could be used to obscure the bulbs in overhead flourescent light applications (or other light sources) or may be used in applications where no specific graphics are illuminated, i.e., such as an on/off indicator for a gasoline pump.  
           [0006]    It is yet another aspect of the present invention to provide a cost effective method for manufacturing a backlit light source which utilizes conventional materials and inks which are applied on one or more substrates, and which allow for the illumination of signs even in daylight conditions to indicate an “on/off” source for users, such as signs used at gasoline stations and fast food drive through restaurants. As discussed hereinbelow, this result is obtained by utilizing a novel ink diffusion formulation which is applied with consideration of the thickness of materials, the color and image being backlit, the distance between the LEDs and the graphic panel, the color and strength of LEDs associated with the backlit sign, and other factors related thereto. Thus, for different applications and types of backlit signs, the type of diffuser material, LEDs, and other materials may vary as appreciated by one skilled in the art.  
           [0007]    Thus, in one aspect of the present invention a backlit sign is provided for illuminating an image, and comprises:  
           [0008]    a substrate layer having a front side and a backside;  
           [0009]    a background ink layer applied to said backside of said substrate having at least one distinct color;  
           [0010]    at least one additional ink layer applied to said background ink to create an image;  
           [0011]    a diffuser layer applied to said at least one additional ink and comprising:  
           [0012]    a) an opaque white gloss vinyl ink having a percentage by weight of between about 20%-30%;  
           [0013]    b) a clear mixing gloss vinyl ink having a percentage by weight of between 50%-60%;  
           [0014]    c) a matte additive ink in a percentage by weight of between about 15%-20%; and  
           [0015]    a light source provided behind said diffuser layer.  
           [0016]    In an alternative embodiment of the present invention, the diffuser may be formulated without utilizing the matte additive inks. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a front elevation view of an embodiment of the present invention showing a backlit sign;  
         [0018]    [0018]FIG. 2 is a front elevation view of a portion of the embodiment shown in FIG. 1;  
         [0019]    [0019]FIG. 3 is a rear elevation view of a portion of the embodiment shown in FIG. 1;  
         [0020]    [0020]FIG. 4 is a exploded perspective view of a portion of the embodiment shown in FIG. 1; and  
         [0021]    [0021]FIG. 5 is a cross sectioned bottom plan view of the embodiment shown in FIG. 4. 
     
    
     DETAILED DESCRIPTION  
       [0022]    Referring now to the drawings, FIGS.  1 - 5  show one embodiment of the present invention. More specifically, these figures depict the backlit portion of a sign and the preferred layers of substrates and inks required to achieve the light distorting effect.  
         [0023]    Referring now to FIG. 1, one embodiment of the present invention is shown herein. The embodiment illustrated incorporates the teachings of the invention into the sign  2 , which contains text  5  and an image  7 . For example, the “Place Speedpass HERE” and “Speedpass™”  5  with the associated illuminated tiger image  7  may be used at a gasoline station or in other applications where illumination is required behind an image  7  to provide instructions and/or other information, or to indicate, for example when a gas pump is operational. The sign  2  shown is only one example of any number of types of signs and images which may utilize the present invention.  
         [0024]    Referring now to FIGS.  2 - 5 , an example of the image  7  portion of an entire sign  2  is shown herein. The image  7  is constructed such that a light source is obscured. Various layers are stacked in order to achieve this effect. As a result, the front and the rear of the image  7  will have different appearances as shown in FIG. 3, which depicts a real image of the sign shown in FIG. 2.  
         [0025]    Referring now to FIG. 3, a front exploded view of the present invention is provided, and which depicts the various layers and substrates required to create a sign of the present invention. Initially, a substrate  8  is laid down which will provide a canvas for the sign&#39;s text  5  and images  7  and will also protect the image  7  when finished. In one embodiment, the substrate is made of pressure sensitive vinyl, liquid vinyl, self-cling vinyl, surface-treated polyester, polycarbonate, or a acrylic, or similar material, preferably Makrofol EPC 0.015 to 0.020 inches thick. A background color  9 A is applied to the substrate. In one embodiment, the background color  9 A is a dark blue high gloss, flexible ink sold by Coates™ as a color in the C99 series. The background color  9 A is applied with a mesh of 255 openings/in 2  and a tension of 14-21 newtons, with regard to the screen used in the image manufacturing process. An additional ink series color combination  9 B, such as the orange, may be utilized to create the image  7  and/or text. In one embodiment, the image  7  is created by a four-color process that includes the application of at least Coates™ C99/HG with a mesh of 255 openings/in 2  and a tension of 14-21 newtons, and Nazdar™ 9700 with a mesh of 355 openings/in 2  and a tension of 20-22 newtons. After the surface  9  is applied a visual inspection for anomalies and pinholes may be performed.  
         [0026]    Numerous inks and the materials associated with the background  9 A and the image  9 B can be used. For example, END 7190, END 7248, END 7249, which are specific color indicators used in this example by Marconi Commerce Systems of Greensboro, N.C., and which identify specific tones and colors used to make various signs and graphic displays. As appreciated by one skilled in the art, the number of colors and inks utilized in any given backlit sign are essentially limitless and can be used in any combination as necessary to produce the desired backlit sign or display.  
         [0027]    Next, another layer  11  of gloss vinyl ink is then provided on top of the previously painted surface  9 , which includes in one embodiment a white ink such as Coates™ C99 11A. Preferably, this layer is applied with a mesh of 255 openings/in 2  and at a tension of 14-21 newtons. This layer  11  may also include additional inked portions  11 B which match areas of the image  7  &amp;  9 B in order to add color or contrast to the final product. After the surface  11  is applied a visual inspection for anomalies and pinholes may be performed.  
         [0028]    Subsequently, an additional layer  12  that acts to prevent unwanted light from emanating from the back is applied. In one embodiment, this opaquing layer  12  consist at least of a mixture of Coates™ Series C99 inks such as CRES-Lite #200, ET-10, and a viscosity reducer S103 (opaque white ink), applied with a mesh of 255 openings/in 2  and at a tension of 14-21 newtons. This layer  12  may also include and additional portions  12 B which match areas of the image  7 ,  9 B, &amp;  11 B in order to add color or contrast to the final product. Furthermore, an additional opaque layer of ink  13  which is merely the application of a second coat as identified herein, can be added to cover pinholes.  
         [0029]    Referring again to FIG. 4, a diffuser layer  14 , which disperses the light source in order to avoid “hot spots”, is now applied on top of the opaquing layer  12  or  13 . In one embodiment, the diffusing layer  14  consists of a mixture of Coates™ Series C99, specifically S199 (a clear mixing agent), S103 (white opaque), and MAT-190 (matte additive), and is applied with a mesh of 255 holes/in 2  at a tension of 14-21 newtons. Alternatively, the matte additive can be omitted. After application, the diffusing layer may be inspected to ensure that the light sources are sufficiently dispersed. Preferably, no pinholes should be present and a photometer reading of 1050-1200 lumins should be read. It should be understood that the diffusing layer is applied between the image  7  and the light source  18 , regardless of the intervening layers present. Alternatively, the diffusing layer  14  can be applied to another material, preferably silk screen, and then placed between the image  7  and the light source  18 .  
         [0030]    To create a sufficiently backlit sign which is capable of brightly illuminating an image  7  or sign  2 , yet which diffuses the illuminating source to such a degree that the LED or other light source  18  is not visible from the viewing front, a specific and novel type of diffuser technique and method must be utilized. Thus, in one particular embodiment of the present invention Coates™ C99-S199, C99-S103, and Mat-190 inks are applied in the weight percentages as identified herein to formulate the composition of the diffuser  14 . More specifically, the C99-S103 is a gloss vinyl ink which is an opaque white color while the C99-S199 is a gloss vinyl ink which has a clear color, while the Mat-190 is a matte additive used for mixing purposes. In one embodiment of the present invention, the C99-S199 is used in a percentage of between about 50% and 60%, and preferably 56%, the C99-S103 is used in a percentage of between about 20% and 30% and preferably 24%, while the matte additive Mat-190 is used in a range of between 10% and 25%, and preferably 20% for the application shown in the attached figures. Alternatively, it has been found that in one embodiment an adequate diffuser  14  can be formulated by entirely eliminating the Mat-190, and utilizing the S199 in a percentage of about 65%, and the S103 in a percentage of about 35%. Variations in the compositions of ink and weight percentages may be substituted as appreciated by one skilled in the art. The combination is preferably mixed inward for 15 minutes and then mixed outward for 15 minutes at a maximum blend speed of 10 using an M&amp;R Turnabout D/C high speed mixer.  
         [0031]    In order to further describe and enable one to construct this embodiment of the present invention the following table is provided.  
                                           Index #   Ink/Formula   Mesh/Tension   Inspection                    8   Makrofol EPC &amp; similar   N/A   Visual for scratches on full           .015 &amp; .020       sheets before being cut to size.                   Cut sheets checked for scratches                   prior to printing.        9A   Coates C99   255 openings/in 2     Visual/Denso               14-21 newtons        9B   Nazdar 9700   355 openings/in 2 /20-22   Visual/Denso           C99/HG   newtons               255 openings/in 2 /14-21               newtons       11   Coates C99   255 openings/in 2     Visual/Denso               14-21 newtons       12   Coates C99   255 openings/in 2     Visual/Even coverage with no           CRES-Lite #200 (75 g)   14-21 newtons   pin holes. Also used behind           ET-10 (50 g) (reducer)       image area that is not backlit to           S103 (385 g) (opaque white)       show contrast.       13   Coates C99   255 openings/in 2     Visual/Use only if necessary to           CRES-Lite #200 (75 g)   14-21 newtons   cover pin holes.           ET-10 (50 g) (reducer)           S103 (385 g) (opaque white)       14   Coates C99   255 openings/in 2     Visual/18″ for 5 seconds,           S199 (448 g) (mixing clear)   14-21 newtons   perpendicular, eye level. No pin           S103 (192 g) (opaque white)       holes. Must not see diameter of,           Mat-190 (160 g) (matte       or count LEDs. Photometer           additive)       reading: 1050-1200       15   3M 468MP   N/A   Backlit area free of adhesive.           Adhesive       Selective cut not over image.                   Must pass adhesive pull test.                  
 
         [0032]    To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein:  
         [0033]    [0033] #  Description  
         [0034]    [0034] 2  Sign  
         [0035]    [0035] 5  Text on a sign  
         [0036]    [0036] 7  Image on a sign  
         [0037]    [0037] 8  Substrate surface  
         [0038]    [0038] 9  Image coat(s)  
         [0039]    [0039] 9 A Background color  
         [0040]    [0040] 9 B Image color(s)  
         [0041]    [0041] 11  White flood layer  
         [0042]    [0042] 11 A White flood ink  
         [0043]    [0043] 11 B Image enhancing portion of white flood layer  
         [0044]    [0044] 12  Opaqueing layer  
         [0045]    [0045] 12 A Opaqueing portion of the layer  
         [0046]    [0046] 12 B Image enhancing portion of the opaqueing layer  
         [0047]    [0047] 13  Optional opaqueing layer  
         [0048]    [0048] 13 A Opaqueing portion of the optional layer  
         [0049]    [0049] 13 B Image enhancing portion of the optional opaqueing layer  
         [0050]    [0050] 14  Diffusing layer  
         [0051]    [0051] 15  Adhesive  
         [0052]    [0052] 16  Clear polycarbonate door  
         [0053]    [0053] 18  Light source(s)  
         [0054]    As appreciated by one skilled in the art various percentages and combinations of the diffuser materials, and/or alternative materials and process steps may be utilized to obtain similar results as provided herein. Thus the present invention is not limited to the specific embodiment as set forth above and in the claims, but includes all equivalent compositions and process steps which capture the novelty of the present invention.