| 摘要 |
PROBLEM TO BE SOLVED: To prevent plastic deformation of a plastic lens by forming a surface modified layer on the surface of a plastic lens and to provide a plastic lens having high strength at the yielding point by further forming a surface protective layer of high hardness on the surface modified layer. SOLUTION: A plastic objective lens 22 has a surface modified layer 24 on the surface of a plastic lens base body 23 of the lens 22 by irradiation of ions to modify the surface, and the lens has a surface protective layer 25 formed by irradiation of ions on the surface modified layer 24. The surface modified layer 24 and surface protective layer 25 are preferably formed by irradiation of ions using ion sources. The surface protective layer 25 is preferably formed as a thin film using carbon or the like by laser ablation method. The surface modified layer 24 and surface protective layer 25 are preferably made of DLC having more SP3 bonds than SP2 bonds. |
