| 摘要 |
PROBLEM TO BE SOLVED: To lower a noise generated from an opening and shutting body equipment. SOLUTION: The noise or the like generated in the case of operation of an opening and shutting body means, for example, in the case of opening operation, a shutting operation and both opening and shutting operations is muffled by means of an active noise controller means. A control sound generated from the active noise controller means has the same amplitude as that of the noise, and it is an acoustic wave of an anti-phase. The control sound and the noise are interfered with each other by pronouncing the control sound from a speaker to muffle the noise in a shutter case, and the noise is lowered. COPYRIGHT: (C)2004,JPO
|
