| 摘要 |
PROBLEM TO BE SOLVED: To provide a fly eye lens which improves the uniformity of illumination efficiency and which decreases the directional dependence of coherency s of the illumination light even when the illuminating light is transmitted for exposure while the fly eye lens is partly covered by using a diaphragm, and to provide a projection exposure device equipped with this lens. SOLUTION: At least the peripheral part of the lens consists of a lens unit 22 of an annular element lens 21 having a fan-shaped cross section. Plural of annular element lenses 21 having each a fan-shaped cross section are connected to form the annular lens unit 22. The lens units having different outer diameters are concentrically assembled so that the element lenses are radially and concentrically arranged to obtain an annular fly eye lens. |
