@techreport{oai:ipsj.ixsq.nii.ac.jp:00209739,
 author = {信太, 仰平 and 和田, 有司 and 中村, 健太郎 and Kohei, Shida and Yuji, Wada and Kentaro, Nakamura},
 issue = {1},
 month = {Feb},
 note = {センシング用途に加え，微小物体の非接触マニピュレーションやハプティックデバイスなどへ空中超音波の応用が広がっている．そこでは数 10 素子のアレイが用いられている．しかし，標準的な空中超音波トランスデューサは厚さなどの寸法が大きい．そこで，本研究では，円板と円環状圧電セラミックス素子だけから成る簡単で低背な構造で必要な音圧を発生できる空中超音波トランスデューサについて解析を行い，試作をとおしてその特性を評価した．外径 8 mm，高さ 1.8 mm で，約 46 kHz で動作するものを試作し，距離 300 mm で 119 dB (=18 Pa) の音圧を得た．指向性の半値全幅は 90°程度であった．共振の Q 値は大振幅時で 86 であった．本稿では，構造と動作原理，有限要素法解析に基づく設計，振動円板の材質を変えた場合の特性などについて述べる．, Application area of airborne ultrasound has been extending from sensing to non-contact manipulation of small objects and haptic devices. In these applications, an array consist of several 10 element transducers is used. There is a strong demand for smaller-sized transducer in thickness. This study deals with a low profile configuration for airborne ultrasonic transducer composed only of a thin vibrating disk and an annular piezoelectric ceramic element, which provides a required sound pressure. The characteristics of the designed transducer was evaluated through prototyping. A trial transducer of 8 mm and 1.8 mm in diameter and thickness successfully produced a sound pressure level of 119 dB (=18 Pa) at the distance of 300 mm and the frequency of around 46 kHz. The full width half maximum of the radiation directivity was approximately 90 degrees. The mechanical Q-value was 86 under high vibration amplitude. The structure, working principle, design based on finite element analysis, and characteristics for different disk materials are described in this report.},
 title = {低背な空中超音波トランスデューサの放射特性},
 year = {2021}
}