Manufacturing process of shadow mask and shadow mask plate therefor
AssigneeDainippon Screen Mfg. Co., Ltd.
InventorsToshio Yamamoto, Koji Sawada
Life of this patent
Estimating the term…
Abstract
A process of manufacturing a shadow mask includes the steps of preparing a plurality of metal plates having a surface deviation characterized in that its Rsk value is not more than 0.3 .mu.m, preferably less than 0, its Sm value is not less than 60 .mu.m, and its Pc value relative to the band of 1 .mu.m width centered about the center line of a roughness profile is not more than 60/cm, forming a plurality of apertures in each of the plates, registrating and piling up the plates upon each other, annealing the plates piled upon each other, and pressing and molding the annealed metal plates into a predetermined curvature. Each of the metal plates preferably has Ra in the range from 0.1 to 0.7 .mu.m.
Claims54
A process of manufacturing a shadow mask suitable for use in a cathode ray tube, comprising the steps of:
- preparing a plurality of metal plates;
- forming a plurality of apertures in said metal plates for passing electron beams therethrough;
- piling up said plurality of metal plates in close contact in such a manner that said apertures formed in each of said metal plates are arranged in a predetermined positional relation;
- annealing said piled up metal plates;
- and
- pressing and molding said piled and annealed metal plates into a predetermined curvature, wherein
- said metal plates are joined to each other in said annealing step due to surface deviation thereof, and remain joined to each other after said passing and molding step as well as after said shadow mask is assembled as an element of a cathode ray tube.
A process of manufacturing a shadow mask suitable for use in a cathode ray tube, comprising the steps of:
- preparing a plurality of metal plates;
- forming a plurality of apertures in said metal plates for passing electron beams therethrough;
- piling up said plurality of metal plates in close contact in such a manner that said apertures formed in each of said metal plates are arranged in a predetermined positional relation;
- annealing said piled up metal plates;
- pressing and molding said piled and annealed metal plates into a predetermined curvature, wherein
- said metal plates are joined to each other in said annealing step due to surface deviation;
- and
- each of said metal plates having a surface deviation characterized in that an Rsk value is not more than 0.3 .mu.m, an Sm value is not less than 60 .mu.m, and a PC value relative to the band of 1 .mu.m width centered about the center line of the roughness profile is not more than 60/cm.
A shadow mask plate for manufacturing a shadow mask suitable for use in a cathode ray tube, comprising
- a metal plate having a surface deviation characterized in that its Ra value is in the range of 0.1 .mu.m and 0.7 .mu.m, its Rsk value is not more than 0.3 .mu.m, its Sm value is not less than 60 .mu.m, and its Pc value relative to the band of 1 .mu.m width centered about the central line is not more than 60/cm.
A process of manufacturing a shadow mask suitable for use in a cathode ray tube, comprising the steps of:
- preparing a plurality of metal plates each having effective and non-effective portions;
- forming a plurality of apertures in said metal plates for passing electron beams therethrough;
- piling up said plurality of metal plates in close contact in such a manner that said apertures formed in each of said metal plates are arranged in a predetermined positional relation;
- spot welding said metal plates at predetermined points of said non-effective portions;
- annealing said piled up metal plates to join said metal plates to each other at their said effective portions;
- and
- pressing and molding said piled and annealed metal plates into a predetermined curvature while said metal plates remained joined to each other at their said effective portions.
A process of manufacturing a shadow mask suitable for use in a cathode ray tube, comprising the steps of:
- preparing a plurality of metal plates;
- forming a plurality of apertures in said metal plates for passing electron beams therethrough;
- forming a plurality of through-holes for registering each of said metal plates into a predetermined position,
- piling up said plurality of metal plates in close contact in such a manner that said apertures formed in each of said metal plates are arranged in a predetermined positional relation;
- annealing said piled up metal plates;
- pressing and molding said piled and annealed metal plates into a predetermined curvature;
- said piling up step including the steps of
- preparing metal plate supporting means having an upper surface for supporting said metal plates and a plurality of pins disposed upright in a positional relation identical to the positional relation between the plurality of through-holes formed in said metal plate;
- and
- piling up a predetermined number of said metal plates upon each other on said metal plate supporting means in such a manner that each of said pins is inserted in said through-hole;
- wherein
- said metal plates are joined to each other during said annealing step and remain joined after said pressing and molding step as well as after said shadow mask is assembled as an element of a cathode ray tube.
Dependencies are inferred from the claim text.