Loudspeaker e.g. for advertising applications, has piezoelectric or electrostatic bending transducer coupled to diaphragm to transmit vibrations

摘要

The loudspeaker has a diaphragm for transmitting vibrations which are produced by at least one piezoelectric or electrostatic bending transducer (2) coupled to the diaphragm. The diaphragm preferably has a thickness in the range 50 to 250 micrometer, and is made of glass fiber reinforced plastics, paper, cardboard, glass, metal or wood. The bending transducer comprises a composite formed from piezoceramic plates, films or fibers and a plastics. Several bending transducers may be coupled together via conductive tracks on the diaphragm.