Color cathode ray tube having a faceplate-mounted support structure with a welded-on high-tension foil shadow mask

Abstract

An improved front assembly for a color cathode ray tube having a tension foil shadow mask is disclosed. The faceplate of the tube has on its inner surface a centrally disposed phosphor target surrounded by a peripheral sealing area adapted to mate with a funnel. A separate metal faceplate frame is secured to the inner surface of the faceplate between the sealing area and the target. The separate metal frame according to the invention supports a welded-on tension foil shadow mask a predetermined distance from the inner surface of the faceplate. The separate faceplate-mounted metal frame may have according to the invention a plurality of slurry-passing structures contiguous to the inner surface of the faceplate for passing any surplusage of slurry during the radial-flow slurry-deposition process used in screening the faceplate. Various configurative embodiments of the faceplate-mounted metal frame according to the invention are also disclosed.

What is claimed is: 
     
       1. A front assembly for a cathode ray tube including a substantially flat faceplate having on its inner surface a centrally disposed phosphor target surrounded by a peripheral sealing area adapted to mate with a funnel, and a stiff faceplate-mounted support structure composed of a weldable metal and secured to said inner surface between said sealing area and said target for supporting a welded-on high-tension foil shadow mask at a predetermined distance from said inner surface of said faceplate, said mask having a central apertured area and a peripheral area which is welded to said support structure, the bond between said support structure and said faceplate being of such area and strength as to resist substantially all of the tensile forces exerted by said foil mask. 
     
     
       2. A front assembly for a cathode ray tube including a substantially flat faceplate on its inner surface a centrally disposed phosphor target surrounded by a peripheral sealing area adapted to mate with a funnel, and a separate stiff faceplate-mounted support structure composed of a weldable metal secured to said inner surface between said sealing area and said target for supporting a welded-on high-tension foil shadow mask stretched in all directions in the plane of said mask a predetermined distance from said inner surface of said faceplate, said mask having a central apertured area and a peripheral area which is welded to said support structure, the bond between said support structure and said faceplate being of such area and strength as to resist substantially all of the tensile forces exerted by said foil 
     
     
       3. A front assembly for a cathode ray tube including a substantially flat faceplate having on its inner surface a centrally disposed phosphor target surrounded by a sealing area having three substantially radially oriented V-shaped grooves therein for indexing said faceplate in conjunction with complementary rounded indexing means on a mating envelope member, said front assembly further including a separate stiff faceplate-mounted support structure composed of a weldable metal secured to said inner surface between said sealing area and said target for supporting a welded-on high-tension foil shadow mask stretched in all directions in the plane of said mask a predetermined distance from said inner surface of said faceplate, said mask having a central apertured area and a peripheral area which is welded to said support structure, the bond between said support structure and said faceplate being of such area and strength as to resist substantially all of the tensile forces exerted by said foil mask. 
     
     
       4. A front assembly for a color cathode ray tube including a substantially flat faceplate having on its inner surface a centrally disposed phosphor target area surrounded by a sealing area with three substantially radially oriented V-shaped grooves therein for indexing said faceplate in conjunction with complementary rounded indexing means associated with a funnel, said front assembly further including a separate discontinuous or segmented faceplate support structure composed of a weldable metal secured to said inner surface between said sealing area and said target for supporting a welded-on high-tension foil shadow mask a predetermined distance from said inner surface of said faceplate, said mask having a central apertured area and a peripheral area which is welded to said support structure, the bond between said support structure and said faceplate being of such area and strength as to resist substantially all of the tensile forces exerted by said foil mask. 
     
     
       5. A front assembly for use in a color cathode ray tube, including a faceplate having on its inner surface a centrally disposed screen-receiving area for receiving a uniform coating of phosphor slurry by the radial flow suffusion process, said front assembly including a separate metal faceplate frame enclosing said screen-receiving area and secured to said inner surface of said faceplate for supporting a welded-on tension foil shadow mask, said faceplate frame having a plurality of slurry-passing structures contiguous to said inner surface for passing any surplusage of slurry during the slurry-deposition process. 
     
     
       6. A front assembly for use in a color cathode ray tube, including a faceplate having on its inner surface a centrally disposed screen-receiving area for receiving a uniform coating of phosphor slurry by the radial flow suffusion process, and a separate metal frame enclosing said screen-receiving area and secured to said inner surface of said faceplate for supporting a welded-on tension foil shadow mask, said separate faceplate-mounted metal frame having a plurality of slurry-passing structures contiguous to said inner surface for passing any surplusage of slurry during the slurry-deposition process, said slurry-passing structures comprising columns affixed to said inner surface and having openings therebetween, said columns having a cross-section effective to promote radial flow of said slurry with minimum washback. 
     
     
       7. The apparatus defined by .[.claims.]. .Iadd.claim .Iaddend.1, 3 .[.and.]. .Iadd.or .Iaddend.5 wherein said frame is of triangular configuration. 
     
     
       8. The apparatus defined by .[.claims.]. .Iadd.claim .Iaddend.1, 3 .[.and.]. .Iadd.or .Iaddend.5 wherein said frame is substantially rectangular in cross-section. 
     
     
       9. The apparatus defined by .[.claims.]. .Iadd.claim .Iaddend.1, 3 .[.and.]. .Iadd.or .Iaddend.5 wherein said frame is substantially trapezoidal in cross-section. .Iadd. 
     
     
       10.  In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which and secured to said inner surface are mask support means which is segmented at its interface with said inner surface. .Iaddend. .Iadd.11. The front assembly according to claim 10 wherein said mask support means are each composed of discrete, independent segments, one side of each of which is cemented to said inner surface and the opposite side of which supports a portion of a tension shadow mask. .Iaddend. .Iadd.12. The front assembly according to claim 10 wherein said segments have rounded ends. .Iaddend. .Iadd.13. The front assembly according to claim 10 wherein said segments are composed of metal. .Iaddend. .Iadd.14. The front assembly according to claim 10 wherein said segments are attached to said inner surface by devitrifying glass frit. .Iaddend. .Iadd.15. The front assembly according to claim 10 wherein each of said mask support means is segmented at its interface with said inner surface, but unsegmented at a distance from said interface. .Iaddend. .Iadd.16. The front assembly according to claim 15 wherein the segments of said mask support means are attached to said inner surface by devitrifying glass frit. .Iaddend. .Iadd.17. The front assembly according to claim 15 wherein said mask is attached to the unsegmented part of said mask support means. .Iaddend. .Iadd.18. The front assembly according to claim 15 wherein said mask support means are composed of metal. .Iaddend. .Iadd.19. In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target enclosed by mask support means along each side of said target, each being composed of discrete, independent segments of metal attached to said inner surface by devitrifying glass frit, said segments supporting a tension foil shadow mask. .Iaddend. .Iadd.20. In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target enclosed by mask support means along each side, each of which is segmented at its interface with said inner surface, said mask support means each presenting at a distance from said interface a metal surface suitable for welding a tension foil shadow mask, said mask support means each being cemented at the segmented interface to said inner surface of said faceplate. .Iaddend. .Iadd.21. In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which are mask support means supporting a tension foil shadow mask, a portion of each of said mask support means which interfaces with said faceplate inner surface being composed of segments having rounded ends. .Iaddend. .Iadd.22. A front assembly for use in a color cathode ray tube, said assembly including a faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which are a plurality of mask support means expanding in cross-section away from said inner surface for supporting a tension foil shadow mask. .Iaddend. .Iadd.23. A front assembly for use in a color cathode ray tube, said assembly including a glass faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which and secured to said inner surface are mask support means supporting a tension foil shadow mask, said mask support means having a different coefficient of thermal expansion than said faceplate, said mask support means being segmented in its area of interface with said glass faceplate to reduce chipping or cracking of said faceplate due to differences in coefficients of thermal expansion of said mask support means means and said faceplate. .Iaddend. .Iadd.24. A front assembly for use in a color cathode ray tube, said assembly including a faceplate composed of glass having a predetermined coefficient of thermal expansion, and having on its inner surface a centrally disposed phosphor target enclosed by a mask support means composed of metal having a coefficient of thermal expansion different from that of said glass faceplate, said mask support means being attached to said faceplate inner surface and supporting a tension foil shadow mask, said mask support means along each side of said target being segmented in its area of interface with said glass and thereby effective to obviate the problem of said difference in coefficients of thermal expansion of said glass and said metal. .Iaddend. .Iadd.25. In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which and secured to said inner surface are mask support means, a portion of each of which mask support means which interfaces with said faceplate inner surface being composed of segments. .Iaddend. .Iadd.26. In a color cathode ray tube, a front assembly including a faceplate having on its inner surface a centrally disposed phosphor target, on each of opposed sides of which and secured to said inner surface are mask support means in the form of a plurality of discrete, independent segments. .Iaddend.