发明名称 Communication terminal device and dialing key
摘要 A communication terminal device including a first switch provided between a button and an intermediate member, and a second switch provided below the intermediate member such that when the button is depressed, both the first and second switches are surely switched on. Both the switches are electrically insulated from each other. Wiring is made such that one of those switches may operate a telephone circuit connected directly to a telephone line while the other switch may operate a main communication unit operating with a commercial power source. Even when the commercial power source is interrupted due to a power stoppage, at least the telephone circuit is operable, so that the terminal device is capable of fulfilling at least the function of a telephone set and ensuring insulation between the telephone unit and the main communication unit.
申请公布号 US5428674(A) 申请公布日期 1995.06.27
申请号 US19940195032 申请日期 1994.02.14
申请人 MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 发明人 KAWASHIMA, SHOJI
分类号 H04M1/23;H04M1/26;H04M1/82;H04N1/327;(IPC1-7):H04M11/00;H04M1/00 主分类号 H04M1/23
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