Light beam scanning apparatus

摘要

A synchronizing light beam applied to a reference grating passes through the reference grating as a pulsed synchronizing light beam, which is converged by a convex entrance surface of a light guide rod onto a rear surface thereof. The synchronizing light beam is then diffused and reflected by a diffusion surface on the rear surface, and applied to photodiodes on respective opposite ends of the light guide rod. The photodiodes converts the applied light to a synchronizing signal.