サブ波長構造による高性能反射防止膜の開発とそのカメラ用レンズへの応用

摘要

Canon Inc. released the new EF 24 mm F 1.4L II USM lens with a subwavelength structure coating (SWC) , a new type of high performance anti-reflective coating, in December 2008. The subwavelength structure, which is made from microcrystalline alumina, can be formed on large, curved surfaces using a simple sol-gel process. Furthermore, by inserting a thin-film layer with an intermediate refractive index between the lens and the microcrystalline alumina, it is possible to achieve superb anti-reflection performance matching various lens refractive indexes. This report presents the principles and performance of SWC and describes the application of SWC to camera lenses.