| 摘要 |
PROBLEM TO BE SOLVED: To provide a data service signal detecting apparatus capable of detecting a data service signal always stably by preventing wrong detection of a positive period of a ternary synchronizing signal as a data service signal. SOLUTION: The data service signal detecting circuit starts to detect the data service signal at the time when a horizontal synchronizing signal finish position is detected by a horizontal synchronizing signal finish position detecting circuit. If a ternary synchronous signal is detected by a ternary signal detecting circuit, the result of detection in the data service signal obtained from the horizontal synchronizing signal finish position up to now is made to be invalid, and the detection of the data service signal is started at the time of detecting the finish position of the positive period of the ternary synchronizing signal.
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