Nitto-denko Corporation

The School Corporation Kansai University

Kohei Oto

Saori Yamamoto

Yusuke Komoto

Tomoaki Hishiki

Yuka Sekiguchi

Ryohei Oban

Yoshinobu Kajikawa

Shun Hirose

A speaker () includes a radiation surface (). The radiation surface () has a first region (), a second region (), and a third region () between the first region () and the second region (). When an axis passing through the third region () and extending away from the radiation surface () is defined as a reference axis (X), the speaker () forms a first wavefront () propagating from the first region so as to approach the reference axis (X) and a second wavefront () propagating from the second region () so as to approach the reference axis (X).

Active noise control system

A piezoelectric speaker () includes a piezoelectric film (), a first joining layer (), and an interposed layer (). The piezoelectric film () includes a first electrode (), a second electrode (), and a piezoelectric body () sandwiched by the first electrode () and the second electrode (). The first joining layer () is a layer having pressure-sensitive adhesiveness or adhesiveness. The interposed layer () is disposed between the piezoelectric film () and the first joining layer (). Both principal surfaces of the piezoelectric film () vibrate up and down as a whole.

Piezoelectric speaker

A sound reducing system () includes at least one sound reducing speaker for radiating a sound wave for sound reduction. The at least one sound reducing speaker includes a piezoelectric speaker (). The piezoelectric speaker () includes a piezoelectric film (), a fixing face () in contact with a support supporting the piezoelectric speaker (), and a film holding portion () disposed between the piezoelectric film () and the fixing face (). (i) The film holding portion () includes a pressure-sensitive adhesive layer and the fixing face () is formed of a surface of the pressure-sensitive adhesive layer and/or (ii) the film holding portion () includes a porous body layer.

Sound reducing system

A piezoelectric speaker () includes: a piezoelectric film (); a fixing face () for fixing the piezoelectric film () to a support; and an interposed layer () disposed between the piezoelectric film () and the fixing face (). The interposed layer () has a holding degree of 5×10N/mor less.

A piezoelectric speaker-forming laminate () includes: a piezoelectric film (); a pressure-sensitive adhesive face (); an interposed layer () being a porous body layer and/or a resin layer disposed between the piezoelectric film () and the pressure-sensitive adhesive face (); and a release layer () joined to the pressure-sensitive adhesive face (). The pressure-sensitive adhesive face () is disposed in such a manner that at least a portion of the piezoelectric film () overlaps the pressure-sensitive adhesive face () when the piezoelectric film () is viewed in plan. The piezoelectric film () and the interposed layer () are allowed to be fixed to a support () as a piezoelectric speaker or a portion of a piezoelectric speaker by sticking the pressure-sensitive adhesive face () from which the release layer () has been removed to the support ().

Growing community of inventors

Osaka, Japan

Kohei Oto