Patent ID: 8462381

Claim:
A dot position measurement method comprising: a line pattern formation step of recording dots on a recording medium continuously by a plurality of recording elements of a recording head while performing relative movement between the recording head and the recording medium in such a manner that a measurement line pattern including a plurality of lines of rows of the dots corresponding to the plurality of recording elements respectively is formed on the recording medium, the measurement line pattern having a plurality of line blocks including recording line blocks and a reference line block, each of the recording line blocks including a group of the lines recorded by the recording elements spaced by a prescribed distance in a direction in which the plurality of recording elements are substantially arranged and which is perpendicular to a direction of the relative movement of the recording head, the reference line block including a group of the lines recorded by the recording elements selected from the recording elements for each of the recording line blocks; a reading step of reading the measurement line pattern on the recording medium formed in the line pattern formation step with an image reading apparatus in a state where a longitudinal direction of the plurality of lines of the measurement line pattern are directed to a sub-scanning direction of the image reading apparatus in such a manner that an electronic image data indicating a read image of the measurement line pattern is acquired; a line block position determination step of determining positions of the respective lines in each of the plurality of line blocks according to the read image acquired in the reading step; and a position correction step of correcting the positions of the respective lines in each of the recording line blocks determined in the line block position determination step, according to the reference line block.