发明名称 |
Remote meter reading apparatus comprising interphone means |
摘要 |
A utility meter in a dwelling or the like is read from a main station through a transmission line. A reverse current blocking diode is provided in the transmission line. Interphones for voice communication are connected to the transmission line at the meter and main station. A bias voltage source forward biases the diode to enable voice communication. |
申请公布号 |
US4151371(A) |
申请公布日期 |
1979.04.24 |
申请号 |
US19770861670 |
申请日期 |
1977.12.19 |
申请人 |
RICOH CO LTD |
发明人 |
ABE, TAKESHI;YOSHIHARA, ICHIRO |
分类号 |
H04M11/00;H04Q9/00;(IPC1-7):H04M11/00 |
主分类号 |
H04M11/00 |
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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