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1. (WO2018123730) AUDIO REPRODUCTION DEVICE

Pub. No.:    WO/2018/123730    International Application No.:    PCT/JP2017/045521
Publication Date: Fri Jul 06 01:59:59 CEST 2018 International Filing Date: Wed Dec 20 00:59:59 CET 2017
IPC: H04R 3/00
G10K 9/122
H04R 17/00
Applicants: CRI MIDDLEWARE CO., LTD.
株式会社CRI・ミドルウェア
Inventors: ISHIGURO, Tetsuo
石黒 哲夫
Title: AUDIO REPRODUCTION DEVICE
Abstract:
[Problem] To provide: a piezoelectric buzzer that is inexpensive, has high-quality sound, and is low in current consumption; and an audio reproduction device that reproduces audio using said piezoelectric buzzer. [Solution] The present invention is provided with: a piezoelectric buzzer 60 having a piezoelectric element PZ that outputs, in the form of audio, vibration generated from a piezoelectric body 61 as a result of applying a signal voltage to the piezoelectric body 61, and having a resistor 65 (R0) that is connected in series to the piezoelectric element PZ and that constitutes a low-pass filter in conjunction with a capacitor equivalent to the piezoelectric element PZ; a microcomputer 20C which generates a PWM signal corresponding to an audio signal; and a drive circuit 20C in which power amplification is carried out by a switching operation performed, on the basis of the PWM signal, by four bipolar transistors constituting an H-bridge circuit 20C and which outputs a signal voltage of low consumption current corresponding to the PWM signal to the piezoelectric buzzer 60, in which the piezoelectric element 61 and the resistor 65 having a resistance value appropriate for the characteristic of the piezoelectric element 61 are connected in series, so as to generate an audio output of the piezoelectric buzzer 60.