| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of occasionally reducing detection accuracy of a moving distance when an attitude of a printing medium inclines to a carrying plane.SOLUTION: The light is irradiated to one surface of the printing medium P, and the light is irradiated at an angle different from a first illuminating means 10 to the one surface. The one surface is imaged by receiving the reflected light of the light irradiated to the one surface, and a plurality of first images expressed by the reflected light when irradiating the light to the first illuminating means 10 without irradiating the light to a second illuminating means 11 are acquired, and a value of indicating similarity of the plurality of first images is calculated. A plurality of second images expressed by the reflected light when irradiating the light to the second illuminating means 11 without irradiating the light to the first illuminating means 10 are acquired, and a value of indicting similarity of the plurality of second images is calculated. The illuminating means so far used when acquiring a set of images existing in the higher relationship in similarity among the similarity of the first images and the similarity of the second images, is selected as illumination used when detecting the moving distance of the printing medium P. |
