オオイシ　クニオ   大石　邦夫    所属   コンピュータサイエンス学部 コンピュータサイエンス学科    職種   教授
言語種別	英語
発行・発表の年月	2013/05
形態種別	国際会議論文
査読	査読あり
標題	A new loudspeaker for low frequency radiation by linear motion type piezoelectric ultrasonic actuators
執筆形態	共著
掲載誌名	International Congress on Acoustics 2013
掲載区分	国外
著者・共著者	Hiroya Saito, Hirokazu Negishi, Juro Ohga, Ikuo Oohira, Kunio Oishi, and Kazuaki Maeda
概要	The authors had proposed new direct-radiator loudspeaker constructions with a conventional paper cone radiator driven by Ultrasonic Motors (USM), as a substitution for voice-coil motor. However, those models needed a revolution to linear motion conversion mechanism, and avoiding zero region non linearity, like class A amplifier. These complications came from the conventional USM, since it is a rotational and having zero region non-linearity inherently. Here, the authors would propose a new mechanism by using new ultrasonic linear actuators, called Longitudinal-Bending Multilayered Transducers with Independent Electrodes (=LBMTIE). The beauty of LBMTIE is linear and to control vertical motion and horizontal motion independently, hence zero region non-linearity avoided. Therefore it is possible to substitute the voice-coil motor directly, which avoid the complicated mechanisms mentioned above. In this LBMTIE driven loudspeaker, vertical movement voltage be fixed and horizontal voltage is driven by audio signal, like voice-coil motor. In addition, there is a big contrast against conventional voice-coil motor, which is a typical transducer; as its electrical input and sound pressure output are direct proportion each other. This is because LBMTIE driven loudspeaker may behave a sort of modulator, which is not direct proportion in between input electric power and output sound pressure level.