Position information is formed on a recording surface 11 of a recording medium 10. The position information is constructed from first line segments, which are parallel to each other, and a second line segment, which crosses the first line segments. On the basis of a distance between (i) an intersection C1 of one of the first line segment and a scan line and (ii) an intersection C2 of another of the first line segments and the scan line, the intersection C2 and an intersection C3 of the second line segment and the scan line are measured or calculated. By this, a position of a head in a Y direction is recognized.