In bi-directional imaging, such as bi-directional printing, a driving
mechanism scans a light beam through a scan path across an imaging
window. A controller enables transmission of video data to a modulator
when the light beam is positioned for imaging on the imaging window.
Video data is transmitted to the modulator when the light beam is
traveling in a forward direction or a reverse direction across the
imaging window, whereby a modulated light beam is capable of producing an
image when traveling in the forward or reverse directions. The controller
adjusts scan durations or image rasterization rates to ensure that each
scan is properly aligned with the prior and subsequent scan.