| 摘要 |
PROBLEM TO BE SOLVED: To provide a telephone terminal for detecting an operation state of a telephone line that detects the states of the telephone line while distinguishing an occupied state of the telephone line, a non-occupied state of the telephone line that is not in use and a non-connection state of the telephone line from each other even when the telephone terminal is not connected to the telephone line. SOLUTION: The telephone terminal is provided with a 1st line voltage detection section 2 and a 2nd line voltage detection section 3 whose detection voltage decision levels differ from each other, and automatically decides an occupied state of the telephone line that is in use, a non-occupied state of the telephone line that is not in use, and a non-connection state of the telephone line where the telephone terminal is not connected to the telephone line respectively through the discrimination of a level of a line voltage without the need for any switching operation by a user.
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