| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve automatic phase adjustment accuracy independently of a noise mixed in transmission from a video signal to quantization part and level variation by change of source video. <P>SOLUTION: A control part 1 obtains a start position change phase for changing a horizontal start position where an output value of an AD converting means becomes a minimum value that exceeds a threshold level and a finish position change phase for changing a horizontal finish position where the output value of the AD converting means becomes a maximum value that exceeds the threshold level for at least threshold levels of two stages by changing successively a phase adjustment value of a quantization clock of the AD converting means 6. A first phase section in which an analogue video signal starts transition to a higher second level from a first level and finishes is calculated from start position change phase and a second phase section in which an analogue video signal starts transition to the first level from the second level and finishes is calculated from the finish position change phase. A phase not included in the first and the second phase sections is set as a quantization clock phase. <P>COPYRIGHT: (C)2011,JPO&INPIT |
