Kabushiki Kaisha Daini Seikosha

Sohya Takahashi

Yoshiaki Hara

Fumikazu Murakami

Shigeo Mori

Ichiro Horikoshi

An electroacoustic transducer particularly for small small-sized portable equipment such as a wristwatch comprises a first vibrating plate which is vibrated by means of an electromagnet and a second vibrating plate which is coupled with the first vibrating plate by an airtight space which acts as an air spring. The first and second vibrating plates have different natural resonant frequencies so that the vibration system comprising the two vibrating plates and the air spring coupling them with one another forms a vibration system having two resonant frequencies. A resonant air chamber superposed on the second vibrating plate has a sound radiating port and has a resonant frequency between the two resonant frequencies of the vibration system comprising the first and second vibrating plates and coupling air spring. The electroacoustic transducer thus responds to a considerable range of frequencies.

Growing community of inventors

Tokyo, Japan

Sohya Takahashi