| 摘要 |
PURPOSE:To send an extracted teletext broadcast signal of each television broadcast channel while being superimposed on a video signal of one channel of a CATV. CONSTITUTION:Plural tuners 1 receive a television signal, demodulates the signal into a composite video signal, plural teletext extract sections 2 extract respectively teletext broadcast signals, and they are stored in a memory section 3. Data read from the memory section 3 are transferred to a buffer memory section 4, in which the data are recorded in plural memory areas based on a signal from a synchronizing signal generating section 9 to be superimposed on the composite video signal for plural horizontal scanning period of a vertical blanking period, the data are superimposed onto a required composite video signal at a superimposition processing section 5, and an RF modulation section 6 modulates the superimposed signal to a signal of each channel of a CATV, a mixer section 7 mixes the signals from the modulation sections and the mixed signal is sent to a CATV network.
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