Abstract: A piezoelectric sound generator module is provided which has a reduced thickness and superior mountability while ensuring good sound pressure characteristics. A sound generating structure and an electronic device, each utilizing the sound generator module, are also provided. The sound generator module has a structure in which a holding member and an acoustic space forming member are bonded to each other while a piezoelectric vibration plate including piezoelectric elements bonded to front and back sides of a vibration plate is held between both the members. A window allowing the piezoelectric vibration plate to vibrate without interference and a lead-out portion are formed in the holding member. An acoustic space, a lead-out portion, and a sound guide path are formed in the acoustic space forming member. By bonding the piezoelectric vibration plate and the acoustic space forming member to the holding member, a thin sound generator module including the sound guide path in itself is formed.

Abstract: It is designed to restrain vibration of a casing, efficiently drive a piezoelectric sounding body (such as a piezoelectric speaker) and flatten sound pressure characteristic within the electronic instrument requiring the miniaturized type, light weight, and thin type in the electronic instrument, in particular the portable telephone. For accomplishing these objects, at a back side of a mass part within the casing of the electronic instrument, the piezoelectric sounding body is mounted via a ring shaped cushioning material. At a part not overlapping with the mass part, a partition is provided. A main air-chamber is tightly formed by the mass part, the piezoelectric sounding body, and the partition, and in the casing within the main air-chamber, a sound issuing hole is formed. The sound outputted from the upper face into the main air-chamber is outputted outside of the casing from the sound issuing hole.

Abstract: A piezoelectric element comprises a metallic plate-shaped diaphragm, a plate-shaped piezoelectric body, and electrodes provided on both surfaces of the piezoelectric body, wherein one electrode is fixed to a main surface of the diaphragm. An extension electrode is extended onto a projection projecting from the diaphragm while it is insulated from the diaphragm. The extension electrode is extended from the diaphragm to the projection while it is insulated from the diaphragm. The extension electrode is electrically connected to the electrode which is not fixed to the diaphragm of the piezoelectric body. The piezoelectric element is attached to a case while allowing a main surface of the projection on which the extension electrode is provided to be directed outward.

Abstract: A piezoelectric acoustic device comprises a case and a piezoelectric element which is accommodated in the case and has an inner peripheral surface thereof supported by an inner peripheral surface of the case at a middle portion thereof. A plurality of projections are provided on an inner peripheral surface of the case and spaced circumferentially along the inner peripheral surface of the case for supporting the peripheral portion of the piezoelectric element. A gap between the peripheral portion of the piezoelectric element and the inner peripheral surface of the case is closed by an elastic adhesive. A plurality of projections provided on and spaced circumferentially along the inner peripheral surface of the case contact the periphery of the piezoelectric element at the tips thereof, which restricts a radial movement of the piezoelectric element relative to the case.