| 摘要 |
A vibrating device includes a dust-screening member which is shaped like a plate as a whole and has at least one side that is symmetric with respect to a symmetry axis, and a vibrating member secured to the dust-screening member and configured to produce, at the dust-screening member, vibration having a vibrational amplitude perpendicular to a surface of the dust-screening member. The vibrating device further includes a drive unit configured to drive the vibrating member to produce vibration Z(x, y) at the dust-screening member, the vibration being expressed as follows: Z(x,y)=Wmn(x,y)·cos(γ)+Wnm(x,y)·sin(γ) where Z(x, y) is vibration at a given point P(x, y) on the dust-screening member, m and n are positive integers including 0, indicating the order of natural vibration corresponding to a vibrational mode, W mn ⁡ ( x , y ) = sin ⁡ ( n ⁢ ⁢ &pgr; · x + &pgr; 2 ) · sin ⁡ ( m ⁢ ⁢ &pgr; · y + &pgr; 2 ) , ⁢ W nm ⁡ ( x , y ) = sin ⁡ ( m ⁢ ⁢ &pgr; · x + &pgr; 2 ) · sin ⁡ ( n ⁢ ⁢ &pgr; · y + &pgr; 2 ) , ⁢ and γ is +&pgr;/4 or ranges from −&pgr;/8 to −&pgr;/4. |
