| 摘要 |
PROBLEM TO BE SOLVED: To accurately perform signal offset correction in long-distance transmission of an analog video signal. SOLUTION: In a signal transmission apparatus, a voltage level of an analog video signal Sp transmitted for a long distance is detected not during a back porch but during a vertical blanking interval VBI. During the vertical blanking interval VBI, the time for detecting the voltage level (voltage level sampling time) can be secured longer than that during the back porch. Therefore, even if there is a portion in which a voltage level is varied with signal attenuation as indicated with a codeΔt in Fig.2(c) or even if skew occurs during signal transmission, the sampling time can be secured long. As a result, voltage level detection accuracy becomes excellent and offset correction of video signals can be accurately performed. COPYRIGHT: (C)2011,JPO&INPIT
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