ANTIREFLECTING OPTICAL ELEMENT

摘要

PURPOSE:To obtain an antireflecting film having durability by forming the innermost layer of the multilayered antireflecting film of a mixed film contg. at least yttrium oxide and zirconium oxide and the outermost layer of a film consisting of silicon dioxide. CONSTITUTION:A synthetic resin substrate subjected to surface hardening treatment is first subjected to cleaning of the surface by using an ordinary multi- stage cleaning device using Freon and is thereafter formed thereon with the three-layered antireflecting film consisting of a mixed film contg. zirconium oxide/yttrium oxide=40/60 (by wt.) as the 1st layer from the substrate side, the film contg. titanium oxide as the 2nd layer and the film contg. silicon dioxide as the 3rd layer by using a vacuum deposition device provided with an electron beam gun. The vapor deposition temp. is 80 deg.C. The surface reflecting interference color of the resulting antireflecting film is magenta and the reflectivity of visible rays is as low as about 0.5%. The adhesion between the antireflecting film and the surface hardened film is accepted in a peeling test by using a cellophane tape. The film is just slightly flawed in the surface hardness test involving rubbing with steel wool. Thus the antireflecting film exhibits excellent performance.