发明名称 |
Digital electro-acoustic transducer |
摘要 |
A digital electro-acoustic transducer for improving the speech quality of sound under noisy circumstances is disclosed. A plurality of sound generating units A constituted by electrostatic electro-acoustic transducers (condenser earphones) and a sound receiving unit B constituted by an electrostatic acousto-electric transducer (condenser microphone) are disposed in a cavity of a soundproof housing. The units A are provided in a feedback loop and an output level of the unit B is adjusted by an preamplifier. An output of the preamplifier is sampled by a sample-and-hold circuit and an output thereof is delta-modulated by a delta modulation circuit. The number of pulses produced by the circuit is subjected to arithmetic operation in an arithmetic circuit to produce a drive signal for the units A. Vibration of a vibration film of the unit B is detected and arithmetical control is made to be always maintained to zero. On the other hand, an audio signal supplied from a signal terminal is superposed on a drive signal for the units A and is emitted into the cavity.
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申请公布号 |
US6449370(B1) |
申请公布日期 |
2002.09.10 |
申请号 |
US19990311142 |
申请日期 |
1999.05.13 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.;RIKO YASUHIRO |
发明人 |
YASUNO YOSHINOBU;RIKO YASUHIRO |
分类号 |
H04R1/00;H04R5/033;H04R19/00;(IPC1-7):H03B29/00;H04R3/00 |
主分类号 |
H04R1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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