| 摘要 |
PURPOSE: A light scanning unit and an electro-photographic image forming apparatus using the same are provided to completely remove a noise of a synchronous noise by arranging output terminals of a beam detection sensor at an edge portion of an optical beam scanning path on a light reception plane. CONSTITUTION: A beam deflector scans an optical beam in main scanning direction, and an optical scanning system collects the optical beam on a scanned surface. A beam detection sensor receives some of optical beams of the beam deflector. The beam detection sensor detects a sync signal from the optical beam. The beam detection sensor includes a light reception surface(163) and at least two output terminals(166,167). At least two output terminals are arranged at the edge portion of an optical beam scanning path of a light reception plane. |
