| 摘要 |
A sheet member adapted for attachment to an acoustic or imaging apparatus to improve the acoustic or imaging performance thereof. The sheet member is generally circular, including a plurality of generally W-shaped cut-outs and a like plurality of generally V-shaped cut-outs both formed alternately and equi-angularly in the outer circumference thereof. The sheet member improves the acoustic or imaging performance by reducing the interference caused by electromagnetic radiations emitted from the acoustic or imaging apparatus or their components to which the sheet member is attached. The reduction of such interference can be attained also by forming a compact disc, a laser disc, a magnetic tape, a semiconductor chip, a circuit board, a magnetic or IC card or the like in a manner to have such cut-outs in their outer circumference. <IMAGE> |
