Patent ID: 7014289
Filing Date: 2006-03-21
Classification: B41J

Abstract:
1. An image forming device that forms an image on a print paper in an ink jet recording method with at least one head, comprising: main scanning direction moving means for moving a carriage in a main scanning direction, said carriage having said at least one head mounted thereon; paper conveying means for conveying the print paper in a sub-scanning direction; pattern printing means for printing, with said at least one head, a test pattern including predetermined pattern elements; wherein said position detecting means comprises low-resolution position detecting means based on a linear scale provided on a movement path of said carriage and high-resolution position detecting means for detecting a position more than twice as finely as a minimum unit determined by a resolution of said low-resolution position detecting means, wherein said low-resolution position detecting means comprises a counter for counting a timing signal based on said linear scale to determine a low-resolution position of said carriage at a time when said a rising and/or falling edge of a binary signal obtained by said binary conversion means is detected, and wherein said high-resolution position detecting means comprises a timer which is initialized by said timing signal and measures a time with a predetermined clock signal to determine a high-resolution position of said carriage within a unit interval determined by a resolution of said linear scale at a time when said a rising and/or falling edge of a binary signal obtained by said binary conversion means is detected, and wherein a count value of said counter and a measured value of said timer are combined with each other to precisely define the position of the pattern element detected by said pattern detecting means, and said position of the pattern element is compared with a print target position of said pattern element to obtain a mounting deviation amount of the head that printed said pattern element.