Patent ID: 8130254
Filing Date: 2012-03-06
Classification: B41J,G02B

Abstract:
1. An optical scanning apparatus comprising two scanning units, the two scanning units each including: a light source unit; an incident optical system that guides light beams emitted from the light source unit to a deflecting unit; and an imaging optical system that causes the light beams deflected for scanning by a deflecting surface of the deflecting unit to form an image on a surface to be scanned, wherein: in a sub-scanning section, the two scanning units are arranged so as to oppose each other with the deflecting unit interposed therebetween; in the sub-scanning section, the two scanning units are configured such that main scanning planes thereof including an optical reference axis have a different height from a bottom surface of the deflecting unit in the direction of a rotational axis of the deflecting unit; the two scanning units each include a light blocking unit that prevents undesirable light generated by the other scanning unit from entering the corresponding scanning unit; of at least one imaging optical element constituting the imaging optical system, an imaging optical element disposed optically closest to the deflecting unit is arranged such that an optical axis of the imaging optical element is made eccentric in the sub-scanning section so that undesirable light generated by the other scanning unit is caused to travel away from the main scanning plane including the optical reference axis of the corresponding scanning unit.