Patent attributes
The liquid ejection head comprises: a plurality of nozzles through which liquid is ejected; a plurality of pressure chambers which accumulate the liquid to be supplied to the nozzles; a plurality of pressure generating devices which apply pressure to the liquid inside the pressure chambers to eject the liquid through the nozzles; a common flow channel through which the liquid is supplied to the pressure chambers; and a wall which defines the common flow channel, at least a portion of the wall being composed of at least two layers including first and second members, a first surface of the first member coming in contact with the liquid in the common flow channel, the second member being arranged on a second surface of the first member reverse to the first surface, wherein: the first member has a thickness L which satisfies the following condition: L=λ×(2n+1)/4, where λ is a wavelength of an acoustic wave traveling through the first member, and n is an integer not smaller than zero; and an acoustic impedance Z1 of the liquid in the common flow channel, an acoustic impedance Z2 of the first member, and an acoustic impedance Z3 of the second member satisfy one of the following conditions: Z1<Z2<Z3 and Z3<Z2<Z1.
