| 摘要 |
PROBLEM TO BE SOLVED: To detect the moving amount of various kinds of printing media with high accuracy.SOLUTION: LED light is applied to one surface of a printing medium, and laser beam is applied to one surface. By receiving the reflected light of the LED light or laser beam applied to one surface, an image of one surface is picked up. A plurality of LED illumination images to be expressed by the reflected light when the LED light is applied to an LED illuminator without applying laser beam to a laser beam illuminator are acquired. The value indicating the similarity of the plurality of LED illumination images is calculated. A plurality of laser beam illumination images to be expressed by the reflected beam when the laser beam is applied to the laser beam illuminator without applying LED light to the LED illuminator are acquired. The value indicating the similarity of the plurality of laser beam illumination images is calculated. An illuminator used when acquiring a set of the images having the higher similarity between the similarity of the LED illumination images and the similarity of the laser beam illumination images is selected as the illumination to be used for detecting the amount of movement of the printing medium. |
