METHOD FOR DETECTING DISPLACEMENT OF DROPLET HITTING POINT AND METHOD FOR DETECTING SIZE OF DROPLET HITTING POINT

摘要

PPROBLEM TO BE SOLVED: To provide a method for detecting displacement of droplet hitting points which enables correct and simple calculation, and to provide a method for detecting a size of the droplet hitting point. PSOLUTION: A plurality of ink liquid droplets are ejected from ejecting parts, respectively, whereby a droplet hitting line is formed for every ejecting part on a medium to be recorded. An image composed of the droplet hitting lines formed on the medium is read as a reading image, and the reading image is subjected to image processing. Pixels of both ends of each droplet hitting line in a reference axis direction are detected by every predetermined interval in a direction orthogonal to the reference axis. Coordinates of the pixels are calculated as position information of ends of the droplet hitting line. On the basis of the position information of the ends of the droplet hitting line, an approximate straight line connecting one end to one end of each of the droplets hitting lines formed from one ejecting part, and an approximate straight line connecting the other end to the other end are calculated for every ejecting part with inclinations of all approximate straight lines being made common. An interval of the droplet hitting points and the size of the droplet hitting point are calculated on the basis of the approximate straight lines obtained for every ejecting part. PCOPYRIGHT: (C)2008,JPO&INPIT