| 摘要 |
PURPOSE:To enable uniformity of form, pitch etc. of pores over a shadow mask for a color picture tube, by forming the shadow mask while regulating the coarseness of its surface by using mild steel etc. and forming pores by photoetching. CONSTITUTION:Over a plate material of a mild steel- or iron-nickel type alloy, or an iron-nickel-cobalt type alloy, buffing or acid cleansing is applied to regulate the surface coarseness within the center line means coarseness (Ra) 0.1- 0.4mum according to B0601, JIS, and the material is formed. Photoetching is applied thereon to prepare numerous circular pores, and a shadow mask for a color picture tube is made up. Thus, by regulating coarseness of the material surface within a specific coarseness, unevenness of form and pitch of pores caused by too much smooth surface is prevented, and a high accuracy and minuteness of the shadow mask can be secured. |
