Patent ID: 8523308

Claim:
A recording head adjustment method comprising: a dot row forming step of causing relative movement between a recording medium and a recording head in which a plurality of sub-heads each including a plurality of recording elements are joined together, and driving the plurality of recording elements at prescribed drive timing with respect to each of the plurality of sub-heads in such a manner that dot rows for the respective sub-heads are formed in a direction substantially perpendicular to a direction of the relative movement; a step-difference amount calculation step of measuring positions in the direction of the relative movement of the dot rows for the respective sub-heads in a situation where a range of a part of the dot rows formed by an overlapping portion between the mutually adjacent sub-heads where recording rates represented by number of dots per unit surface area are substantially same as each other is set as a measurement object, and obtaining an amount of step difference between the sub-heads represented by difference or ratio of the measured positions in the direction of the relative movement of the dot rows for the respective sub-heads; an adjustment value calculation step of calculating an adjustment value for the drive timing of the plurality of recording elements with respect to each of the plurality of sub-heads according to the obtained amount of step difference; and a drive timing adjustment step of adjusting relative drive timing with respect to each of the plurality of sub-heads according to the calculated adjustment value, wherein: in the dot row forming step, a plurality of first dot rows in the direction substantially perpendicular to the direction of the relative movement are formed at a prescribed arrangement interval in the direction of the relative movement by using one sub-head of the mutually adjacent sub-heads, and a second dot row in the direction substantially perpendicular to the direction of the relative movement is formed between the plurality of first dot rows by using the other sub-head of the mutually adjacent sub-heads, and in the step-difference amount calculation step, the amount of step difference between the mutually adjacent sub-heads is calculated according to measurement result of measuring pitches between the plurality of first dot rows and the second dot row.