| 摘要 |
An optical scanning system includes a light source, a condenser lens for condensing a bundle of rays, a first image forming lens for converging the bundle of rays passed through the condenser to form a line image along a main scanning direction, a deflector having a deflection mirror to reflect the line image, and a second image forming lens for converging the bundle of rays deflected by the deflector on a scanning surface so as to form a scanning spot thereon. The second image forming lens includes a single lens. An imaginary converging point of the bundle of rays through the condenser behind the scanning surface is positioned in conjugate relation with the scanning surface. The deflection mirror is positioned in conjugate relation with the scanning surface. The single lens has a distorted cylindrical surface wherein refractive power in the sub-scanning direction varies along the main scanning direction and a toric surface wherein refractive power is positive and different for each of the main and sub scanning directions.
|
