Title:
OPTICAL ELEMENT, OPTICAL SYSTEM, AND OPTICAL EQUIPMENT
Document Type and Number:
Japanese Patent JP2016018095
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an optical element, an optical system and optical equipment having an antireflection film that can maintain an excellent antireflection effect on a substrate composed of a material having a medium to low refractive index.SOLUTION: An optical element 100 is provided, which includes a substrate 110 made of glass transparent to light in a use wavelength region from 400 nm to 700 nm and an antireflection film 120 formed on the substrate. The antireflection film includes, successively from the substrate side, a first layer 122 as an inorganic oxide film essentially comprising silica, a second layer 124 as an inorganic oxide film, and a third layer 130 as a film containing silica fine particles. The antireflection film satisfies specific conditions in regard to a refractive index Nk of the substrate, a refractive index n1 and a physical film thickness d1 (nm) of the first layer, a refractive index n2 and a physical film thickness d2 (nm) of the second layer, and a refractive index n3 and a physical film thickness d3 (nm) of the third layer.SELECTED DRAWING: Figure 1
Inventors:
AMANO SAYOKO
MOMOKI KAZUHIKO
UCHIDA KAZUE
MOMOKI KAZUHIKO
UCHIDA KAZUE
Application Number:
JP2014141201A
Publication Date:
February 01, 2016
Filing Date:
July 09, 2014
Export Citation:
Assignee:
CANON KK
International Classes:
G02B1/11; B32B7/02; B32B9/00; B32B17/06
Attorney, Agent or Firm:
Ryosuke Fujimoto
Atsushi Mizumoto
Hirayama Tomoya
Atsushi Mizumoto
Hirayama Tomoya