| 摘要 |
PROBLEM TO BE SOLVED: To vibrate a dust-screening member at a high vibrating speed over a wide range so as to improve a capability of removing dust sticking on the dust-screening member. SOLUTION: A vibrating device includes a dust-screening filter 119 being a dust-screening member shaped like a plate as a whole, a piezoelectric element 120a as a first vibrating member secured onto the dust-screening member and configured to cause, when driven alone, the dust-screening member to undergo first standing-wave vibration, and a piezoelectric element 120b as a second vibrating member secured onto the dust-screening member and configured to cause, when driven alone, the dust-screening member to undergo second standing-wave vibration. The two piezoelectric elements are positioned so that when the two piezoelectric elements are vibrated, the first standing-wave vibration and second standing-wave vibration overlap each other, thus producing a travelling wave propagating in one direction and having nodes regions 177Y at an outer circumferential side of the dust-screening member, the node regions having virtually no vibrational amplitude. COPYRIGHT: (C)2010,JPO&INPIT |
