| 摘要 |
PURPOSE:To detect a focal state with simple configuration and processing. CONSTITUTION:An out of focus discrimination chart 16 of a 2-dimensional form in which a parameter representing a focal state such as a difference between a maximum value of picture data and a minimum value of the data varies with a read position in the subscanning direction 52 is prepared, the chart 16 is read by an image sensor, and when a distance L of a read position from a reference position 53 while the read parameter is a prescribed setting value is smaller than a prescribed expected value, it is discriminated that out of focus takes place. |
