| 摘要 |
Television receiving apparatus receives television signals broadcast over preselected broadcast channels by different television broadcast systems. A plurality of demodulators (27, 28) demodulate and concurrently display the television programme broadcast by the different systems. A processor (26) selects a broadcast channel to be demodulated by at least one of the demodulators (27, 28); and a detector (32) detects if television signals are being broadcast over the selected channel. If so, the sound carrier frequency derived from the broadcasted television signal is determined and the television broadcast system is identified as a function of that carrier frequency. A memory (33) stores an indication of the selected broadcast channel and the identity of the television broadcast system which uses that channel; whereafter the processor (26) is advanced to select yet another channel and to identify the system by which television signals are broadcast over that other channel. As this process continues, the memory (33) stores indications of channels which can be received and identities of the systems of those channels. Subsequently, desired broadcast channels together with the identities of the systems can be retrieved from the memory (33) to configure the respective demodulators (27, 28) in a manner compatible with those systems to enable the programmes which are broadcast over the retrieved channels to be demodulated and concurrently displayed, such as in a picture-in-picture format. |
