| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultraviolet ray converging lens capable of forming a spot of diffraction limit by utilizing a light source in an ultraviolet range having a wavelength <=300nm. SOLUTION: This lens is composed, in order from the side of a light source, of a first lens group GI including a meniscus lens whose concave surface confronts the side of a light source and expanding the diameter of a light beam and a second lens group GII composed of a first lens whose convex surface confronts the side of the light source, a second biconcave lens, a third and a fourth biconvex lenses, a fifth and sixth positive meniscus lenses whose convex surfaces confront the side of the light source and all lens elements are formed with quartz. The following conditions: -0.11<f/f1<0.05, 0.30<|rm1|/dm<1.00, rm1<0 are satisfied, where, f, f1, are the focal distances of the whole system and the first lens group, rm1, dm are the radius of curvature and the thickness of the surface of the meniscus lens on the side of the light source.
|
