A scanning system for a printer or scanner that has a beam source that produces a light beam at a point of origin and has a scanning mirror that sweeps the light beam from a position “A” to a position “B.” A lens receives the light beam from the scanning mirror and directs the light beam as a scanning beam to an image plane surface. A first synchronizing mirror intercepts and reflects a light ray to a photo detection system when the scanning beam is at a position “A′” that is in the vicinity of position “A” and between position “A” and “B”. A second synchronizing mirror intercepts a light ray when the scanning beam is at a position “B′” that is in the vicinity of position “B” and between position “A” and “B”, and reflects the light ray to a folding mirror that reflects the light ray to the photo detection system. In some configurations two photo detection systems are used in lieu of the folding mirror. In some instances, the lens is a focusing lens and when the scanning beam is at position “A′” and when the scanning beam is at position “B′”, equal optical path lengths are established between (1) the point of origin and the photo detection system and (2) the point of origin and virtually to the image plane surface such that the light ray arriving at the photo detection system is well focused.