| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum cleaner capable of muting a sound to a noise in a high-frequency range without lowering the efficiency of an electric blower in a simple structure. SOLUTION: The vacuum cleaner includes: an air exhaust route 11 for introducing exhaust air from the electric blower 8 to a body air outlet 4, a sensing means 17 for sensing the noise propagating through the route 11, a sound source 15a for generating a control sound for canceling the noise inside the route 11, a sound receiving means 18 for sensing the sound interfered with the noise and the control sound, and a control means for controlling an amplitude and a phase of the control sound, wherein the route 11 is divided into a plurality of channels and an acoustic transmission part 14 is provided between the source 15a and the adjoining channels. With this structure, the noise in the high-frequency range is propagated through the plurality of channels formed on the route 11 respectively as a plane wave with the approximately equal phase, thereby being muted to the noise in the high-frequency range and enabling comfortable use with a low noise without lowering the efficiency of the electric blower in independent and active noise muting systems with the number smaller than that of the channels. COPYRIGHT: (C)2009,JPO&INPIT
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