Method of forming fluorescent screen of cathode ray tube
AssigneeSony Corporation
InventorsSaori Kawase, Hiroshi Kato, Tsuyoshi Kaneko
Life of this patent
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Abstract
A method of forming a phosphor layer of a fluorescent screen of a CRT, having a good screen quality by properly managing the dissolution of a water glass and barium acetate occurring in a covering water step and improve the uniformity. A phosphor layer is formed on an inner surface of a panel portion of a glass bulb by a precipitation process and a lacquer intermediate film is formed on the phosphor layer in a state where the phosphor layer is moistened by covering water. An electrolyte remaining in the phosphor layer after the phosphor layer is moistened by the covering water has a conductivity of 6.0.+-.4.0 .mu.s/cm in 200 ml of pure water of 20.degree. C..+-.1.degree. C.
Claims13
A method of forming a fluorescent screen for a cathode ray tube having a glass bulb, comprising the steps of:
- cleaning an inner surface of the glass bulb having a panel portion by using at least pure water;
- injecting an aqueous solution of electrolyte into the glass bulb;
- depositing a suspension of water glass and phosphor slurry on an inner surface of the panel portion;
- drying the suspension to form a phosphor layer;
- coating a whole surface of the phosphor layer with pure water from 30 to 180 seconds;
- spraying a lacquer comprising an acrylic resin on the wetted phosphor layer to form a lacquer film layer;
- forming a metal backing layer on the lacquer film layer;
- and
- heating the glass bulb to remove the lacquer film layer at a temperature at 400.degree. C. to 420.degree. C.
A method of preparing a phosphor layer on a surface of a glass bulb to receive a metal backing layer thereon to form a fluorescent screen for a cathode ray tube comprising coating an entire surface of a dried phosphor layer with water for 30 to 180 seconds prior to forming a metal backing layer on said phosphor layer, where, during said coating, water glass and an electrolyte, which are both constituents of said phosphor layer, dissolve in said water.
A method of preparing a phosphor layer on a surface of a glass bulb to receive a metal backing layer thereon to form a fluorescent screen for a cathode ray tube, comprising dissolving an electrolyte constituent of said phosphor layer by applying a film of water to an entire surface of said phosphor layer, said dissolving continuing until a conductivity of the electrolyte remaining in the phosphor layer is 6.0.+-.4 .mu.s/cm in 200 ml of pure water at 20.degree. C..+-.1.degree. C.
Dependencies are inferred from the claim text.