| 摘要 |
<p>PURPOSE:To improve the efficiency of ultrasonic wave generation by giving a medium body for resonance amplification to an ultrasonic oscillator in an IC card. CONSTITUTION:An ultrasonic oscillator 1 which transmits and receives information by an ultrasonic wave, its electrode 11, and a medium body 3 for resonance amplification consisting of a metallic material are laminated in the IC card main body, and dimensions and materials of the ultrasonic oscillator 1 and the medium body 3 for resonance amplification are so selected that Q is high in the natural oscillation mode. The periphery of the ultrasonic oscillator 1 is filled up with an oscillation absorbent for the purpose of preventing unnecessary oscillation from being transmitted to an integrated circuit part. Since the ultrasonic oscillator is provided with the medium body for resonance amplification, the ultrasonic wave is efficiently generated.</p> |
