PURPOSE: To obtain an automatic video interruption unit that can be connected to even a television receiver with no exclusive input terminal nor a exclusive circuit but only with a common external input terminal.

CONSTITUTION: When a visitor operates a doorphone 2 while television broadcast is being received, a signal generated by the doorphone 2 is transmitted to an interphone 3 and an interruption detection circuit 6. The interruption detection circuit 6 outputs an interruption signal to a microcomputer 22 for control. The microcomputer 22 for control supplies a power supply from a power switching circuit 8 to a door camera 1, puts the door camera 1 into an operating state and switches a video switching circuit 21 to the door camera to output the video signal from the door camera 1 to a video signal output terminal 12. This video signal is transmitted to the video input terminal of the television receiver as monitor and a video is projected there.