摘要 |
PURPOSE:To weight respective piezoelectric vibrating parts, to directly input each bit signal of a digitized audio signal, and to reproduce audio by making the respective numbers of the piezoelectric ceramic layers of the plural piezoelectric vibrating parts different to each other. CONSTITUTION:Plural piezoelectric vibrating parts 13-16 driven by each bit signal of the digital input signal are stuck on a diaphragm 11 composed of an elastic body. Further, the respective numbers of piezoelectric ceramic layers 12 interposed between electrodes are made different to each other so that the respective piezoelectric vibrating parts 13-16 can generate sound pressure corresponding to the weight of each bit digit of the digital input signal. Thus, the respective piezoelectric vibrating parts 13-16 can be driven for every bit digit, and a PAM wave, namely, the continuous waveform of an original sound can be reproduced by inputting each bit signal of a binary code to the respective piezoelectric vibrating parts 13-16. |