| 摘要 |
PROBLEM TO BE SOLVED: To provide a double tape type aperture grille of simple structure manufacturable easily, capable of momentarily damping the vibration of the tape part chiefly for 100-600 Hz, and sustaining practical application satisfactorily. SOLUTION: A double tape type aperture grille is formed so that the overlapping tape portions have natural frequencies, different not less than 0.5% or have densities or moduli of elasticity different not less than 1%. It is preferable that the two tape portions are made of different metals or alloys having different compositions, and still more preferable that they consist of iron, nickel, and/or alloys chiefly containing such elements.
|
