APERTURE GRILLE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an aperture grille which does not become an off- specification product after blackening treatment. SOLUTION: This aperture grille is obtained by applying blackening treatment to a plated coat with the surface formed of iron or a metal layer containing iron, to form a black coat on the surface. In this constitution, the slit spacing of the aperture grille before blackening treatment is wider by 1-10μm than the slit spacing of the aperture grille after blackening treatment.