Embodiments of the invention relate to writing servo patterns onto a recording disk with a high degree of accuracy and with correct phases in a servo-pattern-writing process. An In-Drive SSW (TSSW) process is processing to write product servo patterns onto a recording disk on the basis of time aligned patterns. In the processing to write product servo patterns onto a recording disk, time intervals between time aligned patterns already written on an ID-side track are measured, and timings to write the product servo patterns onto the recording disk on the basis of the measured time intervals are determined. Product servo patterns are then written onto an OD-side track with the determined timings relative to detections of the time aligned patterns used as references. In this way, circumferential-direction positions of product servo patterns written on a track may be aligned to the corresponding circumferential-direction positions of product servo patterns written on an adjacent track.