| 摘要 |
PROBLEM TO BE SOLVED: To provide an image display device for correctly displaying an image while obtaining reproduction dot clocks of an optimum frequency corresponding to the kinds of video signals. SOLUTION: The kinds of the inputted video signals are estimated based on the total number of vertical lines, and the frequency dividing ratio of a PLL portion is temporally set as a predetermined value corresponding to an estimated kind. Next, the frequency dividing ratio is so calculated that the actually measured value of the horizontal display width measured in a video detection section and the capturing width which is the horizontal display width that can be captured in a frame memory coincide with each other, and the calculated horizontal display width and the calculated frequency dividing ratio is converted to a multiple of 4. Then, the phase of the reproduction dot clocks for the video signals is adjusted by using the reproduction dot clocks created in the PLL portion based on the converted frequency dividing ratio. Further, the frequency dividing ratio is recalculated in such a manner that the actually measured value of the horizontal display width measured in the video detection section by using the phase-controlled reproduction dot clocks and the calculated frequency dividing ratio is set again in the PLL portion. COPYRIGHT: (C)2008,JPO&INPIT |
