Dye combinations for image enhancement filters for color video displays

Abstract

A bandpass filter containing specific red dyes alone or in combination with other dyes selectively transmits predetermined primary color wavelengths as well as selectively absorbs wavelengths other than the predetermined primary color wavelength. The filter is particularly useful for enhancing the contrast of color plasma displays by absorbing visible light emitted at 590 nm from the display.

What is claimed is:  
     
         1 . A filter for contrast and color enhancement of a color display, comprising either a first dye having substantially the absorbance spectrum as shown in FIG. 1, or a second dye having substantially the absorbance spectrum as shown in FIG. 2, or a mixture of said first and second dyes uniformly contained in a carrier matrix.  
     
     
         2 . The filter of  claim 1 , comprising a mixture of said first and second dyes, said mixture containing about 0.02% to about 0.85% by weight of said first dye and about 0.01% to about 0.45% by weight of said second dye, said weights based on said matrix.  
     
     
         3 . The filter of  claim 1 , wherein the filter is a multiple bandpass filter comprising said first and second dyes, Astrazon Orange dye and Luxol Fast Blue dye uniformly contained in the matrix.  
     
     
         4 . The filter of  claim 2 , further containing Astrazon Orange in amounts of about 0.02% to about 2.0% by weight and Luxol Fast Blue in amounts of about 0.02% to about 2.0% by weight, based on the matrix.  
     
     
         5 . The filter of  claim 4 , further containing Disperse Yellow 9 dye uniformly contained in the matrix in amounts of about 0.20% to about 0.80% by weight based on the matrix.  
     
     
         6 . The filter of claims  3 , further containing IRA 850 dye uniformly contained in the matrix.  
     
     
         7 . The filter of  claim 1  wherein said matrix is a polymer matrix.  
     
     
         8 . The filter of  claim 7 , wherein the polymer matrix comprises polyvinyl alcohol, polyvinyl acetate, polymethyl methacrylate, polyacrylate, polyolefin,, polystyrene, polycarbonate, polyvinyl butyrate, cycloolefin polymer, cycloolefin copolymer, polyurethane, polyamide, polyester, polyether, polyketone, or polyesteramide.  
     
     
         9 . The filter of  claim 1 , wherein said first and second dyes have a light fastness characterized as less than 10-20% degradation under 85 MJ/m 2  exposure of white light and a thermal stability characterized as less than 10-20% degradation under conditions of 70° C., 70% RH for 72 hours.  
     
     
         10 . The filter of  claim 3 , comprising a first layer formed from a mixture of said first and second dyes uniformly contained within a polymer matrix, and a second layer juxtaposed on said first layer and comprising a mixture of Astrazon Orange dye and Luxol Fast Blue dye uniformly contained within a polymer matrix.  
     
     
         11 . The filter of  claim 10 , wherein the first layer comprises a polymethyl methacrylate matrix.  
     
     
         12 . The filter of  claim 11 , wherein the second layer comprises polyvinyl acetate matrix.  
     
     
         13 . The filter of  claim 1  wherein said matrix is coated onto a transparent substrate selected from glass and a polymeric substrate.  
     
     
         14 . The filter of  claim 1  wherein said matrix is a free standing polymeric film.  
     
     
         15 . A color display device comprising: 
 A face plate containing an inner and outer surface, the inner surface comprises a layer of phosphor and the outer surface comprises a translucent filter;    The filter comprises either a first dye having substantially the absorbance spectrum as shown in FIG. 1, or a second dye having substantially the absorbance spectrum as shown in FIG. 2, or a mixture of said first and second dyes, incorporated in a carrier matrix.    
     
     
         16 . The color display device of  claim 15 , wherein the filter further comprises Astrazon Orange dye and Luxol Fast Blue dye contained uniformly in a carrier matrix.  
     
     
         17 . The color display device of  claim 16 , wherein the filter further comprises Disperse Yellow 9 dye incorporated in a carrier matrix.  
     
     
         18 . The color display device of  claim 1  wherein said carrier matrix is a polymer.  
     
     
         19 . The color display device of  claim 18 , wherein the polymer matrix is composed of polyvinyl alcohol, polyvinyl acetate, polymethyl methacrylate, polyacrylate, polyolefin,, polystyrene, polycarbonate, polyvinyl butyrate, cycloolefin polymer, cycloolefin copolymer, polyurethane, polyamide, polyester, polyether, polyketone, or polyesteramide.  
     
     
         20 . The color display device of  claim 16 , wherein the filter comprises a first layer comprising a mixture of said first and second dyes contained in a polymeric matrix and a second layer comprising Astrazon Orange dye and Luxol Fast Blue dye contained in a separate polymeric matrix.  
     
     
         21 . The color display device of  claim 21 , wherein the first layer comprises a polymethyl methacrylate matrix and the second layer comprises a polyvinyl acetate matrix.  
     
     
         22 . The color display device of  claim 15  wherein said matrix is coated onto a transparent substrate selected from glass and polymeric substance.  
     
     
         23 . The color display device of  claim 15  wherein said matrix is a free standing polymeric film.  
     
     
         24 . The color display device of  claim 15  comprising a plasma display device.  
     
     
         25 . A plasma display device and an image enhancement filter provided thereon, said filter comprising at least one red dye capable of absorbing visible light emitted at 590 nm.  
     
     
         26 . The plasma display device of  claim 25  wherein the filter is capable of absorbing at least 50% of visible light emitted at 590 nm.  
     
     
         27 . The plasma display device of  claim 25  wherein said at least one red dye is contained within a polymeric matrix.  
     
     
         28 . The plasma display device of  claim 27  wherein the carrier matrix is coated onto a transparent substrate selected from glass and polymer substance.  
     
     
         29 . The plasma display device of  claim 27  wherein said matrix is a free standing polymeric film.  
     
     
         30 . The plasma display device of  claim 25 , further comprising IRA 850 dye capable of shielding IR radiation emitted form plasma of the plasma display device.  
     
     
         31 . A dye solution comprising a solvent and the dye comprising a dye having substantially the absorbance spectrum as shown in FIG. 1, a dye having substantially the absorbance spectrum as shown in FIG. 2, Astrazon Orange, Luxol Fast Blue, Disperse Yellow 9, IRA 850, or mixtures thereof.  
     
     
         32 . The dye solution of  claim 31 , wherein the solvent is water, or organic solvent or mixtures thereof.  
     
     
         33 . The dye solution of  claim 32  wherein the organic solvent comprises isopropyl alcohol, methyl alcohol, methyethyl ketone, acetone, dimethylfuran or mixtures thereof.