| 摘要 |
PURPOSE:To make the illumination of an illumination optical system uniform, by placing plural compound eye lenses at an inter-main point distance D by 2 groups of a front proup and a rear group, and constituting its many convex lens elements so that a convex surface whose radius of curvature is small is positioned toward the incident light side. CONSTITUTION:In an IC pattern transfer device using an oval mirror, a light source, the first diverging collimation lens, and the second converging collimation lens, etc., as an optical integrator provided on the way from the first collimation lens to the second collimation lens, a single lens element of a compound eye lens of a front group, and a single lens element of a compound eye lens of a rear group are made to form a pair and are placed at an interval of a distance D, and they are constituted so that its focal distance f1 and f2 have an almost equal value, each convex curved surface whose radius of curvature is small is turned toward the incident light beam side, and also the relation of an inequality is satisfied. According to such a constitution, a loss of the quantity of light is reduced, and also unevenness of illumination light can be corrected. |
