Light scanning device with a short-path synchronizing grid

摘要

A scanning light beam is reflectively deflected by a light deflector in a main scanning direction substantially perpendicular to a subscanning direction in which an object surface to be scanned is moved. The deflected scanning light beam is passed through a scanning lens to scan the object surface in the main scanning direction. A synchronizing light beam is applied to the light deflector at a position where the scanning light beam is reflected thereby, in a direction allowing the synchronizing light beam that is reflectively deflected by the light deflector to be applied to the scanning lens. A converging lens is disposed on the optical path of the synchronizing light beam prior to application to the light deflector. The synchronizing light beam having left the scanning lens is passed through a grid and detected by a light detector assembly.