| 摘要 |
PURPOSE:To improve contrast of a cathode ray tube for monochrome display by causing alkali ions in the uppermost layer of a face plate to be exchanged with silver ions, deoxidizing the silver ions to develop a color so as to color the surface of the face plate in amber or yellowish green. CONSTITUTION:The surface of a face plate preheated to 450 deg.C is dipped in eutetic salt of Na2SO4, K2SO4, ZnSO4 or Ag2SO4 which is melt by heating to 450 deg.C. This face plate is held for 30min at 450 deg.C, drawn up and cooled slowly. It is then cooled and washed with water to remove the eutetic salt adhered on the surface of the face plate. Alkali ions in the uppermost layer of the face plate are thereby exchanged with silver ions, and these silver ions are deoxidized to develop a color. The face plate is thus colored in amber or yellowish green for example, and the light transmittance of the face is lowered. Consequently, the contrast of the cathode ray tube can be improved. |
