Image display employing filter coated phosphor particles

Abstract

An image display comprising a viewing screen including a layer of phosphor particles emissive of light of a particular visual color and color filter particles transmissive of light of that color .Iadd.partially .Iaddend.covering .[.between 20 and 80 percent of.]. the surfaces of the phosphor particles.

I claim:  .[. 
     
       1.  An image display comprising a luminescent viewing screen and means for selectively exciting areas of said screen to luminescence, said screen comprising a layer of phosphor particles emissive of light in a particular portion of the visible spectrum, said phosphor particles having adhered to their surfaces color filter particles which are transmissive of light in said portion of the visible spectrum, said color filter particles covering between 20 and 80 percent of the surfaces of said phosphor particles..]. .[.2. The display means defined in claim 1 wherein said viewing screen comprises also a second layer of phosphor particles on said layer of filter-particle-coated phosphor particles on the side thereof opposite the viewing side of said screen, said second layer being free of said color filter particles..]. .[.3. The image display defined in claim 1 consisting essentially of a cathode-ray tube comprising a luminescent viewing screen and means for selectively exciting areas of said screen to luminescence with an electron beam..].  .[.4. A multicolor display comprising a luminescent viewing screen including at least two interlaced patterns of target elements, each pattern of which emits light of a particular color in the visible spectrum upon excitation, and means for selectively exciting each of said elements to emission, each of the elements of one of said patterns being comprised of a layer of phosphor particles which, upon excitation, emit light of a particular color in the visible spectrum, and color filter particles adhered to the surfaces of said phosphor particles, said color filter particles being transmissive of light of said particular color and being absorptive of light of other colors, and covering between 20 percent and 80 percent of the surfaces of said phosphor particles..]. .[.5. The multicolor display defined in claim 4 wherein each of said elements of said one pattern is comprised of a layer of red-emitting phosphor particles and red-transmitting color filter particles adhered to the surfaces of said red-emitting phosphor particles..]. .[.6. The multicolor display defined in claim 4 wherein said phosphor particles are of europium-activated yttrium oxysulfide and said color filter particles are of cadmium sulfo-selenide..].  .[.7. The multicolor display defined in claim 4 wherein each of said elements of said one pattern is comprised of a layer of blue-emitting phosphor particles and blue-transmitting color filter particles adhered to the surfaces of said blue-emitting phosphor particles..]. .[.8. The multicolor display defined in claim 7 wherein said phosphor particles are of silver-activated zinc sulfide and said color filter particles cobalt aluminate..]. .[.9. The multicolor display defined in claim 4 wherein said luminescent viewing screen comprises three interlaced patterns of target elements, one pattern of which is red emitting, one pattern of which is green emitting and one pattern of which is blue emitting..].  .[.10. The multicolor display defined in claim 9 wherein each of the elements of said red-emitting pattern is comprised of a layer of red-emitting phosphor particles and red-transmitting color filter particles adhered to the surfaces of said red-emitting phosphor particles, and each of the elements of said blue-emitting pattern is comprised of a layer of blue-emitting phosphor particles and blue-transmitting color filter particles adhered to the surfaces of said 
     
     
        blue-emitting phosphor particles..]. .Iadd.11.  An image display comprising a luminescent viewing screen and means for selectively exciting areas of said screen to luminescence, said screen comprising a layer of phosphor particles emissive of light in a particular portion of the visible spectrum, said phosphor particles having adhered to their surfaces color filter particles which are transmissive of light in said portion of the visible spectrum, said color filter particles partially covering the surfaces of said phosphor particles, said phosphor particles and said filter particles being present in such proportions that the percent decrease in reflectivity from said layer is at least twice as large as the percent loss in luminescent light output from said layer for the same visual color as compared with a similar layer that is free from filter particles. .Iaddend. .Iadd.12. An image display comprising a luminescent viewing screen and means for selectively exciting areas of said screen to luminescence, said screen comprising a layer of phosphor particles emissive of light in a particular portion of the visible spectrum, said phosphor particles having adhered to their surfaces color filter particles which are transmissive of light in said portion of the visible spectrum, said color filter particles partially covering the surfaces of said phosphor particles, said phosphor particles and said filter particles being present in such proportions that the percent decrease in reflectivity from said layer is at least twice as large as the percent loss in luminescent light output from said layer for the same visual color as compared with a similar layer that is free from filter particles, and wherein the luminescent light output from said layer of the same visual color is at least 90 percent of the light outpt of a similar layer that is free from filter particles. .Iaddend.