| 摘要 |
PURPOSE: A PIP(picture in picture) channel selection device and a method is provided to repeatedly compare until tuning voltage of two signals is in concord, after detecting of a main/sub video signal while searching a channel to possibly exchange channels between the PIPs,and let the channels exchange smoothly. CONSTITUTION: The device comprises: a main/sub video signal demodulating section for demodulating a main/sub IF(intermediate frequency) outputted from a main/sub tuner to a main/sub video image signal and a main/sub SIF(speech intermediate frequency); a main/sub speech signal demodulating section for demodulating a main/sub speech signal from the main/sub SIF demodulating by the main/sub video signal demodulating section; a comparator measure for comparing the main/sub speech signal demodulating by the main/sub speech signal demodulating section; and a controller for storing main/sub tuning voltage of equivalent channels by varying tuning voltage of a main/sub tuning tuner to search an auto channel, and storing detected tuning voltage of the same channel according to relative output of the comparator. |
