To switch automatically a video image displayed on a view finder by automatically switching ON/OFF of a return signal.

A timing set variable resistor 46 is used to set the number of switching times of ON/OFF per minute and an oscillator 48 outputs a signal with a frequency depending on the setting. An output terminal of the oscillator 48 is connected to a base terminal of a transistor(TR) 52 via an automatic changeover switch 50 and a moving contact 54B of a relay switch 54 is closed/ open by an output signal from the oscillator 48. The signal denoting the ON/ OFF of the relay switch 54 is fed to a control circuit of the camera and the control circuit automatically switches a video image displayed on a view finder. Thus, it is possible to automatically switch a picked-up image of other cameraman and an image picked-up by himself alternately for a desired period.