DOKIKAIRO

摘要

PURPOSE:To extremely accurately sample a video signal by obtaining the synchronization of the video signal and a sampling clock signal and correcting the phase difference between a horizontal synchronizing signal and the video signal when the video signal to be inputted is sampled. CONSTITUTION:While a two-phase sampling clock signal 103 is generated in the internal part, the sampling clock signal 103 is switch-synchronized with a supplied horizontal synchronizing signal 101 as a reference, and further, the phase difference between a video signal 102 and the horizontal synchronizing signal 101 is detected with the synchronized sampling clock signal as the reference, a delay is added either to the horizontal synchronizing signal 101 or to the video signal 102, and the synchronization is executed. Thus, since the three signals, which are the sampling clock signal, the horizontal synchronizing signal, and the video signal, are completely synchronized, the supplied video signal 102 can be sampled accurately without generating any dot omission and dot formation even when the phase difference exists between the video signal 102 and the horizontal synchronizing signal 101, and further, a period is long, in which the video signal 102 is not supplied.