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经营范围
发明名称
Manufacture of electroacoustic devices
摘要
申请公布号
US2173481(A)
申请公布日期
1939.09.19
申请号
US19380235751
申请日期
1938.10.19
申请人
BELL TELEPHONE LABORATORIES, INCORPORATED
发明人
KALIN WALTER
分类号
H04R29/00
主分类号
H04R29/00
代理机构
代理人
主权项
地址
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