US Patent 7398689 Piezo inkjet printer

An inkjet printer containing a substantially closed ink duct and a transducer used to generate a pressure wave in the duct, wherein the transducer comprises a first part and, separate from the first part, a second part whereby, by actuation of the transducer, the first part manifests a first deformation and the second part simultaneously manifests a second deformation actually opposed to the first deformation, such that a pressure wave is generated in the ink duct.