Patent ID: 7031039
Filing Date: 2006-04-18
Classification: B41J

Abstract:
1. An optical scanning apparatus for scanning a plurality of surfaces to be scanned, comprising: a plurality of light sources; an optical deflector for deflecting and reflecting a plurality of light beams emitted from the plurality of light sources; and an imaging optical system for guiding the plurality of light beams which are deflected and reflected by the optical deflector to the different surfaces to be scanned, wherein: the plurality of light beams incident on the optical deflector are incident on a deflection surface of the optical deflector at different angles to a normal of the deflection surface withing a sub scanning section, the imaging optical system comprises a first optical element, the first optical element is commonly used for the plurality of light beams; optical power of the first optical element satisfies 0≦|φ the imaging optical system further comprises a plurality of second optical elements respectively provided for the plurality of light beams, and each of the plurality of second optical elements has optical power in a sub scanning direction, such that optical power of the first optical element and optical power of each of the plurality of second optical elements within a main scanning section are represented by φ each of the plurality of second optical elements has a shape in which at least one of a light incident surface and a light exit surface is spherical within a main scanning section; and optical power on the off-axis of each second optical element is lower than optical power on the on-axis of each second optical element within the sub scanning section.