First delay mechanisms to delay a beam-detect signal by different lengths of time in synchronization with a first clock signal. The beam-detect signal is generated responsive to one or more beams being output towards a rotating polygonal mirror having facets and directed towards a sensor. One or more second delay mechanisms each correspond to one of the beams to delay a second clock signal, resulting in a beam-clock signal to align the beam over successive reflections by the facets. A mechanism determines a delay by which each second delay mechanism is to delay the second clock signal, based on the beam-detect signal as differently delayed by the first delay mechanisms.