To improve the detection efficiency of synchronization signal by precisely detecting the synchronization signal, when a video signal is a weak electric-field signal, and when V-sag is generated.
An effective pixel/VB period determining section 120 determines whether a video signal is in an effective pixel period or in a VB period. Furthermore, a minimum detection section 130 detects a minimum value of a signal level in a detection period determined, according as to whether the video signal is in the effective pixel period or in the VB period. Then a minimum value decision section 140 decides whether the detected minimum value is an adequate value, and then a threshold calculation section 150 finds a threshold for synchronizing the signal detection, according to whether the minimum value is adequate. Once the threshold is found, a synchronization separation section 160 outputs the signal, when the level of the input video signal decreases below the threshold as a synchronization signal.
NORITAKE TOSHIYA
TAKEDA MIHO
Hiroshi Koyama
Hiroshi Takeuchi
Takahisa Shimada
Yuji Takeuchi
Katsumi Imae
Atsushi Fujita
Kazunari Ninomiya
Tomoo Harada
Iseki Katsumori