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Telephone terminal device

  • US 5,157,711 A
  • Filed: 08/28/1990
  • Issued: 10/20/1992
  • Est. Priority Date: 08/31/1989
  • Status: Expired due to Fees
First Claim
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1. A telephone terminal device having a battery power supply and adapted for connection with an office line, comprising:

  • (a) battery power checking means, responsive to a call signal sent through said office line, for checking a power supply capability of said battery power supply by using power of said signal;

    (b) office line acquisition means for acquiring said office line;

    (c) first office line acquisition control means responsive to said call signal, for driving said office line acquisition means by said power of said call signal, when said battery power checking means determines that said power supply capability of said battery power supply is insufficient;

    (d) second office line acquisition control means responsive to said call signal, for driving said office line acquisition means by power supplied from said battery power supply, when said battery power checking means determines that said power supply capability of said battery power supply is sufficient; and

    (e) power supply means for receiving power supplied through said office line acquired by said office line acquisition means and for supplying received power to said telephone terminal device as device driving power.

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