| 摘要 |
PURPOSE: A method for recognizing broadcasting mode in a multi-system television is provided to set up a broadcasting mode automatically with one free-run operation when channel is turned. A user does not need to handle keys. CONSTITUTION: If the user requests channel turn, a tuner is tuned to a selected channel(204). The tuner outputs received broadcasting signal to a mode switching part. If the user does not requests channel turn, a broadcasting mode which was set up previously is outputted to a CRT. The mode switching part outputs synchronizing signal to the micro processor. The micro processor determines whether broadcasting signal modulation mode is negative modulation mode by basing on the synchronizing signal(206). If the broadcasting signal modulation mode is not negative modulation, the micro processor recognizes broadcasting mode as SECAM-L mode, and outputs mode switching signal to the mode switching part(206a). If the broadcasting signal modulation mode is negative modulation, the micro processor determines whether a voice carrier frequency is 5.5 MHz(208). If the voice carrier frequency is 5.5 MHz, the micro processor recognizes broadcasting mode as PAL-B/G mode, and outputs mode switching signal to the mode switching part(208a). If the voice carrier frequency is not 5.5 MHz, the micro processor determines whether the voice carrier frequency is 6.0 MHz(210).
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