| 摘要 |
PURPOSE:To attain automatically monitor starting operation and monitor completing operation by detecting a calling signal of a door phone, turning on the power supply of a television camera and the monitor television only for a fixed period and displaying a monitor video. CONSTITUTION:A television controller 5 consists of a calling detecting circuit 6, a camera control part 7, a television power supply control part 8 and a signal change over part 9. During a calling time from the door phone 1, a visitor is checked by the monitor video automatically displayed on the monitor television 4. When it is decided that the reception is not required, a hand set of an interphone 3 is not raised, and then the power supply of the television camera 2 and the monitor television 4 is automatically turned off after the preset fixed time. When the hand set is raised to receive the visitor, the power supply of the television camera 2 and the monitor television 4 is automatically turned off when the reception is completed and the hand set is returned and the monitored state is released.
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