摘要:
A deviation test pattern includes a reference scale printed by one reference printing unit among a plurality of printing units arranged to print overlaid images of yellow, magenta, cyan and black. The reference scale has a plurality of scale bars arranged in a main-scanning direction at a pitch of 30 dots. Particularly, the deviation test pattern further includes a difference scale printed adjacent to and in parallel to the reference scale by a printing unit other than the reference printing unit. The difference scale has a plurality of scale bars arranged in the main-scanning direction at a pitch of 29 dots (or 31 dots).