| 摘要 |
PROBLEM TO BE SOLVED: To prevent an image, in the way to listen audio (music), from being displayed in a television receiver on the terminal side, when only the audio (music) having no video is broadcast, in a digital modulator generating a television broadcast signal.SOLUTION: A digital modulator includes input terminals 12, 14 for inputting a video signal and an audio signal, a coding unit 24 for encoding the input signal, a multiplexing unit 26 for multiplexing additional data to the digital data encoded in the coding unit, and a modulation unit 28 for generating a television broadcast signal from a TS signal generated in the multiplexing unit. The input section of broadcast signal is provided with detectors 16, 18 for detecting the audio signal and video signal, a black screen generation unit 20 for generating the video signal of black screen, and a video switching unit 22 for inputting a video signal generated in the black screen generation unit 20 to the coding unit 24, when an audio signal is detected in the detectors 16, 18, and a video signal is not detected. |
