Method for producing electron tube

摘要

It is an object of the present invention to present a method for producing an electron tube capable of preventing agglomeration of particles contained in coating material to be coated on an shadow mask to form an electron beam reflecting film, that causes settling of the particles on a shadow mask or clogging of the coating system, and fluctuations of pressure for supplying the coating material to a spray nozzle, that cause unstable quantity by weight of the coating material discharged from the nozzle and excessive coating, thereby preventing deterioration of the quality of images. An electron beam reflecting film of high surface coverage can be formed for the electron tube with a small quantity by weight of the coating material containing bismuth oxide particles which have an average particle diameter D50 of 0.6 mum or less and a particle size distribution with the particles having a diameter between D40 and D60 accounting for at least 20% by volume of the total particles. This method supplies the coating material by oscillations of a piezoelectric element to the spray nozzle, or scans the nozzle just by slanting the nozzle at varying angles while keeping a head between the surface of the coating material in a coating material storage section and the nozzle center.