| 摘要 |
PURPOSE:To provide a television modulator being able to display a time without any broadcast or various messages of a next broadcast time on its screen even at a time when no broadcast is executed. CONSTITUTION:The television modulator installed to a center equipment side of the CATV system, applying high frequency modulation to a video signal inputted from an input section and outputting a modulated signal to a CATV transmission line is provided with a video signal detection circuit 12 detecting the presence of the input of the video signal and sending a resulting detection signal, a video signal transmission means 13 sending a predetermined pattern or the like as a video signal, a changeover means 11 connecting selectively an output section to an input section or the video signal transmission means 13, and a central processing unit 9 controlling the changeover means 11 and the video signal transmission means 13 based on the detection signal from the video signal detection circuit 12. |
