| 摘要 |
An optical scanning apparatus, including an incident system that allows a beam from the light source to enter to deflector; and an imaging system that images the beam deflected by the deflector on a scanning surface, in which the incident system includes a first and second systems, the first system includes first and second elements each having a positive power with rotational symmetry, the light source is positioned at a shorter distance from the front focus position of the first element, the first element is formed integrally as a unit, powers of the second element and the first system, magnifications within main and sub-scanning sections of entire system, and focus movement within the main and sub-scanning sections on the scanning surface when the second element is moved in the optical axis direction are appropriately set. |
