| 摘要 |
An achromatic, telecentric f-theta scan lens optical system (10) for a raster output scanner has a positive crown glass lens element (12), a negative flint lens element (14) and a concave mirror (16). The refractive indices of the positive crown glass lens element (12) and the negative flint lens element (14) are sufficiently different to achieve achromatization of a light beam by the two lens elements. The positive crown glass lens element (12), the negative flint lens element (14) and the concave mirror form a telecentric optical system. <IMAGE> |
